Biological and nonbiological complex drugs for multiple sclerosis in Latin America: regulations and risk management.

PubMed

Carrá, Adriana; Macías Islas, Miguel Angel; Tarulla, Adriana; Bichuetti, Denis Bernardi; Finkelsztejn, Alessandro; Fragoso, Yara Dadalti; Árcega-Revilla, Raul; Cárcamo Rodríguez, Claudia; Durán, Juan Carlos; Bonitto, Juan García; León, Rosalba; Oehninger Gatti, Carlos; Orozco, Geraldine; Vizcarra Escobar, Darwin

2015-06-01

Biological drugs and nonbiological complex drugs with expired patents are followed by biosimilars and follow-on drugs that are supposedly similar and comparable with the reference product in terms of quality, safety and efficacy. Unlike simple molecules that can be copied and reproduced, biosimilars and follow-on complex drugs are heterogeneous and need specific regulations from health and pharmacovigilance agencies. A panel of 14 Latin American experts on multiple sclerosis from nine different countries met to discuss the recommendations regarding biosimilars and follow-on complex drugs for treating multiple sclerosis. Specific measures relating to manufacturing, therapeutic equivalence assessment and pharmacovigilance reports need to be implemented before commercialization. Physical, chemical, biological and immunogenic characterizations of the new product need to be available before clinical trials start. The new product must maintain the same immunogenicity as the original. Automatic substitution of biological and complex drugs poses unacceptable risks to the patient.

Immunogenicity assessment during the development of protein therapeutics.

PubMed

Rosenberg, Amy S; Sauna, Zuben E

2018-05-01

Here we provide a critical review of the state of the art with respect to non-clinical assessments of immunogenicity for therapeutic proteins. The number of studies on immunogenicity published annually has more than doubled in the last 5 years. The science and technology, which have reached a critical mass, provide multiple of non-clinical approaches (computational, in vitro, ex vivo and animal models) to first predict and then to modify or eliminate T-cell or B-cell epitopes via de-immunization strategies. We discuss how these may be used in the context of drug development in assigning the immunogenicity risk of new and marketed therapeutic proteins. Protein therapeutics represents a large share of the pharma market and provide medical interventions for some of the most complex and intractable diseases. Immunogenicity (the development of antibodies to therapeutic proteins) is an important concern for both the safety and efficacy of protein therapeutics as immune responses may neutralize the activity of life-saving and highly effective protein therapeutics and induce hypersensitivity responses including anaphylaxis. The non-clinical computational tools and experimental technologies that offer a comprehensive and increasingly accurate estimation of immunogenic potential are surveyed here. This critical review also discusses technologies which are promising but are not as yet ready for routine use. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Use of In Vitro Assays to Assess Immunogenicity Risk of Antibody-Based Biotherapeutics

PubMed Central

Joubert, Marisa K.; Deshpande, Meghana; Yang, Jane; Reynolds, Helen; Bryson, Christine; Fogg, Mark; Baker, Matthew P.; Herskovitz, Jonathan; Goletz, Theresa J.; Zhou, Lei; Moxness, Michael; Flynn, Gregory C.; Narhi, Linda O.; Jawa, Vibha

2016-01-01

An In Vitro Comparative Immunogenicity Assessment (IVCIA) assay was evaluated as a tool for predicting the potential relative immunogenicity of biotherapeutic attributes. Peripheral blood mononuclear cells from up to 50 healthy naïve human donors were monitored up to 8 days for T-cell proliferation, the number of IL-2 or IFN-γ secreting cells, and the concentration of a panel of secreted cytokines. The response in the assay to 10 monoclonal antibodies was found to be in agreement with the clinical immunogenicity, suggesting that the assay might be applied to immunogenicity risk assessment of antibody biotherapeutic attributes. However, the response in the assay is a measure of T-cell functional activity and the alignment with clinical immunogenicity depends on several other factors. The assay was sensitive to sequence variants and could differentiate single point mutations of the same biotherapeutic. Nine mAbs that were highly aggregated by stirring induced a higher response in the assay than the original mAbs before stirring stress, in a manner that did not match the relative T-cell response of the original mAbs. In contrast, mAbs that were glycated by different sugars (galactose, glucose, and mannose) showed little to no increase in response in the assay above the response to the original mAbs before glycation treatment. The assay was also used successfully to assess similarity between multiple lots of the same mAb, both from the same manufacturer and from different manufacturers (biosimilars). A strategy for using the IVCIA assay for immunogenicity risk assessment during the entire lifespan development of biopharmaceuticals is proposed. PMID:27494246

Structure-based Design of Cyclically Permuted HIV-1 gp120 Trimers That Elicit Neutralizing Antibodies*

PubMed Central

Kesavardhana, Sannula; Das, Raksha; Citron, Michael; Datta, Rohini; Ecto, Linda; Srilatha, Nonavinakere Seetharam; DiStefano, Daniel; Swoyer, Ryan; Joyce, Joseph G.; Dutta, Somnath; LaBranche, Celia C.; Montefiori, David C.; Flynn, Jessica A.; Varadarajan, Raghavan

2017-01-01

A major goal for HIV-1 vaccine development is an ability to elicit strong and durable broadly neutralizing antibody (bNAb) responses. The trimeric envelope glycoprotein (Env) spikes on HIV-1 are known to contain multiple epitopes that are susceptible to bNAbs isolated from infected individuals. Nonetheless, all trimeric and monomeric Env immunogens designed to date have failed to elicit such antibodies. We report the structure-guided design of HIV-1 cyclically permuted gp120 that forms homogeneous, stable trimers, and displays enhanced binding to multiple bNAbs, including VRC01, VRC03, VRC-PG04, PGT128, and the quaternary epitope-specific bNAbs PGT145 and PGDM1400. Constructs that were cyclically permuted in the V1 loop region and contained an N-terminal trimerization domain to stabilize V1V2-mediated quaternary interactions, showed the highest homogeneity and the best antigenic characteristics. In guinea pigs, a DNA prime-protein boost regimen with these new gp120 trimer immunogens elicited potent neutralizing antibody responses against highly sensitive Tier 1A isolates and weaker neutralizing antibody responses with an average titer of about 115 against a panel of heterologous Tier 2 isolates. A modest fraction of the Tier 2 virus neutralizing activity appeared to target the CD4 binding site on gp120. These results suggest that cyclically permuted HIV-1 gp120 trimers represent a viable platform in which further modifications may be made to eventually achieve protective bNAb responses. PMID:27879316

Modulating immunogenic properties of HIV-1 gp41 membrane-proximal external region by destabilizing six-helix bundle structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Saikat; Shi, Heliang; Habte, Habtom H.

The C-terminal alpha-helix of gp41 membrane-proximal external region (MPER; {sup 671}NWFDITNWLWYIK{sup 683}) encompassing 4E10/10E8 epitopes is an attractive target for HIV-1 vaccine development. We previously reported that gp41-HR1-54Q, a trimeric protein comprised of the MPER in the context of a stable six-helix bundle (6HB), induced strong immune responses against the helix, but antibodies were directed primarily against the non-neutralizing face of the helix. To better target 4E10/10E8 epitopes, we generated four putative fusion intermediates by introducing double point mutations or deletions in the heptad repeat region 1 (HR1) that destabilize 6HB in varying degrees. One variant, HR1-∆10-54K, elicited antibodies inmore » rabbits that targeted W672, I675 and L679, which are critical for 4E10/10E8 recognition. Overall, the results demonstrated that altering structural parameters of 6HB can influence immunogenic properties of the MPER and antibody targeting. Further exploration of this strategy could allow development of immunogens that could lead to induction of 4E10/10E8-like antibodies. - Highlights: • Four gp41 MPER-based immunogens that resemble fusion intermediates were generated. • C-terminal region of MPER that contains 4E10/10E8 epitopes was highly immunogenic. • Altering 6HB structure can influence immunogenic properties of the MPER. • Induced antibodies targeted multiple residues critical for 4E10/10E8 binding. • Development of immunogens based on fusion intermediates is a promising strategy.« less

Elicitation of Robust Tier 2 Neutralizing Antibody Responses in Nonhuman Primates by HIV Envelope Trimer Immunization Using Optimized Approaches.

PubMed

Pauthner, Matthias; Havenar-Daughton, Colin; Sok, Devin; Nkolola, Joseph P; Bastidas, Raiza; Boopathy, Archana V; Carnathan, Diane G; Chandrashekar, Abishek; Cirelli, Kimberly M; Cottrell, Christopher A; Eroshkin, Alexey M; Guenaga, Javier; Kaushik, Kirti; Kulp, Daniel W; Liu, Jinyan; McCoy, Laura E; Oom, Aaron L; Ozorowski, Gabriel; Post, Kai W; Sharma, Shailendra K; Steichen, Jon M; de Taeye, Steven W; Tokatlian, Talar; Torrents de la Peña, Alba; Butera, Salvatore T; LaBranche, Celia C; Montefiori, David C; Silvestri, Guido; Wilson, Ian A; Irvine, Darrell J; Sanders, Rogier W; Schief, William R; Ward, Andrew B; Wyatt, Richard T; Barouch, Dan H; Crotty, Shane; Burton, Dennis R

2017-06-20

The development of stabilized recombinant HIV envelope trimers that mimic the virion surface molecule has increased enthusiasm for a neutralizing antibody (nAb)-based HIV vaccine. However, there is limited experience with recombinant trimers as immunogens in nonhuman primates, which are typically used as a model for humans. Here, we tested multiple immunogens and immunization strategies head-to-head to determine their impact on the quantity, quality, and kinetics of autologous tier 2 nAb development. A bilateral, adjuvanted, subcutaneous immunization protocol induced reproducible tier 2 nAb responses after only two immunizations 8 weeks apart, and these were further enhanced by a third immunization with BG505 SOSIP trimer. We identified immunogens that minimized non-neutralizing V3 responses and demonstrated that continuous immunogen delivery could enhance nAb responses. nAb responses were strongly associated with germinal center reactions, as assessed by lymph node fine needle aspiration. This study provides a framework for preclinical and clinical vaccine studies targeting nAb elicitation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Peptide Reactivity of Isothiocyanates - Implications for Skin Allergy

NASA Astrophysics Data System (ADS)

Karlsson, Isabella; Samuelsson, Kristin; Ponting, David J.; Törnqvist, Margareta; Ilag, Leopold L.; Nilsson, Ulrika

2016-02-01

Skin allergy is a chronic condition that affects about 20% of the population of the western world. This disease is caused by small reactive compounds, haptens, able to penetrate into the epidermis and modify endogenous proteins, thereby triggering an immunogenic reaction. Phenyl isothiocyanate (PITC) and ethyl isothiocyanate (EITC) have been suggested to be responsible for allergic skin reactions to chloroprene rubber, the main constituent of wetsuits, orthopedic braces, and many types of sports gear. In the present work we have studied the reactivity of the isothiocyanates PITC, EITC, and tetramethylrhodamine-6-isothiocyanate (6-TRITC) toward peptides under aqueous conditions at physiological pH to gain information about the types of immunogenic complexes these compounds may form in the skin. We found that all three compounds reacted quickly with cysteine moieties. For PITC and 6-TRITC the cysteine adducts decomposed over time, while stable adducts with lysine were formed. These experimental findings were verified by DFT calculations. Our results may suggest that the latter are responsible for allergic reactions to isothiocyanates. The initial adduct formation with cysteine residues may still be of great importance as it prevents hydrolysis and facilitates the transport of isothiocyanates into epidermis where they can form stable immunogenic complexes with lysine-containing proteins.

Development of designed site-directed pseudopeptide-peptido-mimetic immunogens as novel minimal subunit-vaccine candidates for malaria.

PubMed

Lozano, José Manuel; Lesmes, Liliana P; Carreño, Luisa F; Gallego, Gina M; Patarroyo, Manuel Elkin

2010-12-06

Synthetic vaccines constitute the most promising tools for controlling and preventing infectious diseases. When synthetic immunogens are designed from the pathogen native sequences, these are normally poorly immunogenic and do not induce protection, as demonstrated in our research. After attempting many synthetic strategies for improving the immunogenicity properties of these sequences, the approach consisting of identifying high binding motifs present in those, and then performing specific changes on amino-acids belonging to such motifs, has proven to be a workable strategy. In addition, other strategies consisting of chemically introducing non-natural constraints to the backbone topology of the molecule and modifying the α-carbon asymmetry are becoming valuable tools to be considered in this pursuit. Non-natural structural constraints to the peptide backbone can be achieved by introducing peptide bond isosters such as reduced amides, partially retro or retro-inverso modifications or even including urea motifs. The second can be obtained by strategically replacing L-amino-acids with their enantiomeric forms for obtaining both structurally site-directed designed immunogens as potential vaccine candidates and their Ig structural molecular images, both having immuno-therapeutic effects for preventing and controlling malaria.

Immunogenicity of biologic therapies: causes and consequences.

PubMed

Boehncke, Wolf-Henning; Brembilla, Nicolo Costantino

2018-04-25

Antibodies or fusion proteins termed biologics allow the targeted therapy of diseases. Many of these agents have proven superior efficacy and safety to conventional therapies, and subsequently revolutionized the management of numerous chronic diseases. Repetitive administration of these protein-based therapeutics to immunocompetent patients elicit immune responses in the form of Anti Drug Antibodies (ADAs), which in turn impact their pharmacological properties and may trigger adverse events. Areas covered: Structural characteristics determining the immunogenicity of biologics are reviewed along with strategies to minimize it. Next, the different types of treatment-emerging ADAs, their potential clinical implications, and assays to detect them are addressed. Emphasis is put on the review of data on the immunogenicity of different types of biologics across numerous indications. Finally, practical considerations are discussed on how to manage patients with issues around the immunogenicity of their biologic treatment. Expert commentary: Immunogenicity is a clinically relevant criterion when selecting a biologic. Besides intrinsic properties of the agent (namely its structure), its respective mode of action, dosing regimen, comedication, and the indication treated must be considered. ADA detection assays need to be standardized to improve comparability of available data and to allow clinical decision-making.

Safety and Immunogenicity of Heterologous Prime-Boost Immunisation with Plasmodium falciparum Malaria Candidate Vaccines, ChAd63 ME-TRAP and MVA ME-TRAP, in Healthy Gambian and Kenyan Adults

PubMed Central

Kimani, Domtila; Jagne, Ya Jankey; Sheehy, Susanne H.; Bliss, Carly M.; Duncan, Christopher J. A.; Collins, Katharine A.; Garcia Knight, Miguel A.; Kimani, Eva; Anagnostou, Nicholas A.; Berrie, Eleanor; Moyle, Sarah; Gilbert, Sarah C.; Spencer, Alexandra J.; Soipei, Peninah; Mueller, Jenny; Okebe, Joseph; Colloca, Stefano; Cortese, Riccardo; Viebig, Nicola K.; Roberts, Rachel; Gantlett, Katherine; Lawrie, Alison M.; Nicosia, Alfredo; Imoukhuede, Egeruan B.; Bejon, Philip; Urban, Britta C.; Flanagan, Katie L.; Ewer, Katie J.; Chilengi, Roma; Hill, Adrian V. S.; Bojang, Kalifa

2013-01-01

Background Heterologous prime boost immunization with chimpanzee adenovirus 63 (ChAd63) and Modified vaccinia Virus Ankara (MVA) vectored vaccines is a strategy recently shown to be capable of inducing strong cell mediated responses against several antigens from the malaria parasite. ChAd63-MVA expressing the Plasmodium falciparum pre-erythrocytic antigen ME-TRAP (multiple epitope string with thrombospondin-related adhesion protein) is a leading malaria vaccine candidate, capable of inducing sterile protection in malaria naïve adults following controlled human malaria infection (CHMI). Methodology We conducted two Phase Ib dose escalation clinical trials assessing the safety and immunogenicity of ChAd63-MVA ME-TRAP in 46 healthy malaria exposed adults in two African countries with similar malaria transmission patterns. Results ChAd63-MVA ME-TRAP was shown to be safe and immunogenic, inducing high-level T cell responses (median >1300 SFU/million PBMC). Conclusions ChAd63-MVA ME-TRAP is a safe and highly immunogenic vaccine regimen in adults with prior exposure to malaria. Further clinical trials to assess safety and immunogenicity in children and infants and protective efficacy in the field are now warranted. Trial Registration Pactr.org PACTR2010020001771828 Pactr.org PACTR201008000221638 ClinicalTrials.gov NCT01373879 NCT01373879 ClinicalTrials.gov NCT01379430 NCT01379430 PMID:23526949

Safety and immunogenicity of heterologous prime-boost immunisation with Plasmodium falciparum malaria candidate vaccines, ChAd63 ME-TRAP and MVA ME-TRAP, in healthy Gambian and Kenyan adults.

PubMed

Ogwang, Caroline; Afolabi, Muhammed; Kimani, Domtila; Jagne, Ya Jankey; Sheehy, Susanne H; Bliss, Carly M; Duncan, Christopher J A; Collins, Katharine A; Garcia Knight, Miguel A; Kimani, Eva; Anagnostou, Nicholas A; Berrie, Eleanor; Moyle, Sarah; Gilbert, Sarah C; Spencer, Alexandra J; Soipei, Peninah; Mueller, Jenny; Okebe, Joseph; Colloca, Stefano; Cortese, Riccardo; Viebig, Nicola K; Roberts, Rachel; Gantlett, Katherine; Lawrie, Alison M; Nicosia, Alfredo; Imoukhuede, Egeruan B; Bejon, Philip; Urban, Britta C; Flanagan, Katie L; Ewer, Katie J; Chilengi, Roma; Hill, Adrian V S; Bojang, Kalifa

2013-01-01

Heterologous prime boost immunization with chimpanzee adenovirus 63 (ChAd63) and Modified vaccinia Virus Ankara (MVA) vectored vaccines is a strategy recently shown to be capable of inducing strong cell mediated responses against several antigens from the malaria parasite. ChAd63-MVA expressing the Plasmodium falciparum pre-erythrocytic antigen ME-TRAP (multiple epitope string with thrombospondin-related adhesion protein) is a leading malaria vaccine candidate, capable of inducing sterile protection in malaria naïve adults following controlled human malaria infection (CHMI). We conducted two Phase Ib dose escalation clinical trials assessing the safety and immunogenicity of ChAd63-MVA ME-TRAP in 46 healthy malaria exposed adults in two African countries with similar malaria transmission patterns. ChAd63-MVA ME-TRAP was shown to be safe and immunogenic, inducing high-level T cell responses (median >1300 SFU/million PBMC). ChAd63-MVA ME-TRAP is a safe and highly immunogenic vaccine regimen in adults with prior exposure to malaria. Further clinical trials to assess safety and immunogenicity in children and infants and protective efficacy in the field are now warranted. Pactr.org PACTR2010020001771828 Pactr.org PACTR201008000221638 ClinicalTrials.gov NCT01373879 NCT01373879 ClinicalTrials.gov NCT01379430 NCT01379430.

A VLP-based vaccine targeting domain III of the West Nile virus E protein protects from lethal infection in mice.

PubMed

Spohn, Gunther; Jennings, Gary T; Martina, Byron Ee; Keller, Iris; Beck, Markus; Pumpens, Paul; Osterhaus, Albert Dme; Bachmann, Martin F

2010-07-06

Since its first appearance in the USA in 1999, West Nile virus (WNV) has spread in the Western hemisphere and continues to represent an important public health concern. In the absence of effective treatment, there is a medical need for the development of a safe and efficient vaccine. Live attenuated WNV vaccines have shown promise in preclinical and clinical studies but might carry inherent risks due to the possibility of reversion to more virulent forms. Subunit vaccines based on the large envelope (E) glycoprotein of WNV have therefore been explored as an alternative approach. Although these vaccines were shown to protect from disease in animal models, multiple injections and/or strong adjuvants were required to reach efficacy, underscoring the need for more immunogenic, yet safe DIII-based vaccines. We produced a conjugate vaccine against WNV consisting of recombinantly expressed domain III (DIII) of the E glycoprotein chemically cross-linked to virus-like particles derived from the recently discovered bacteriophage AP205. In contrast to isolated DIII protein, which required three administrations to induce detectable antibody titers in mice, high titers of DIII-specific antibodies were induced after a single injection of the conjugate vaccine. These antibodies were able to neutralize the virus in vitro and provided partial protection from a challenge with a lethal dose of WNV. Three injections of the vaccine induced high titers of virus-neutralizing antibodies, and completely protected mice from WNV infection. The immunogenicity of DIII can be strongly enhanced by conjugation to virus-like particles of the bacteriophage AP205. The superior immunogenicity of the conjugate vaccine with respect to other DIII-based subunit vaccines, its anticipated favourable safety profile and low production costs highlight its potential as an efficacious and cost-effective prophylaxis against WNV.

Monocyte NOTCH2 expression predicts IFN-β immunogenicity in multiple sclerosis patients.

PubMed

Adriani, Marsilio; Nytrova, Petra; Mbogning, Cyprien; Hässler, Signe; Medek, Karel; Jensen, Poul Erik H; Creeke, Paul; Warnke, Clemens; Ingenhoven, Kathleen; Hemmer, Bernhard; Sievers, Claudia; Lindberg Gasser, Raija Lp; Fissolo, Nicolas; Deisenhammer, Florian; Bocskei, Zsolt; Mikol, Vincent; Fogdell-Hahn, Anna; Kubala Havrdova, Eva; Broët, Philippe; Dönnes, Pierre; Mauri, Claudia; Jury, Elizabeth C

2018-06-07

Multiple sclerosis (MS) is an autoimmune disease characterized by CNS inflammation leading to demyelination and axonal damage. IFN-β is an established treatment for MS; however, up to 30% of IFN-β-treated MS patients develop neutralizing antidrug antibodies (nADA), leading to reduced drug bioactivity and efficacy. Mechanisms driving antidrug immunogenicity remain uncertain, and reliable biomarkers to predict immunogenicity development are lacking. Using high-throughput flow cytometry, NOTCH2 expression on CD14+ monocytes and increased frequency of proinflammatory monocyte subsets were identified as baseline predictors of nADA development in MS patients treated with IFN-β. The association of this monocyte profile with nADA development was validated in 2 independent cross-sectional MS patient cohorts and a prospective cohort followed before and after IFN-β administration. Reduced monocyte NOTCH2 expression in nADA+ MS patients was associated with NOTCH2 activation measured by increased expression of Notch-responsive genes, polarization of monocytes toward a nonclassical phenotype, and increased proinflammatory IL-6 production. NOTCH2 activation was T cell dependent and was only triggered in the presence of serum from nADA+ patients. Thus, nADA development was driven by a proinflammatory environment that triggered activation of the NOTCH2 signaling pathway prior to first IFN-β administration.

Enhanced structural stability of Concholepas hemocyanin increases its immunogenicity and maintains its non-specific immunostimulatory effects.

PubMed

Arancibia, Sergio; Del Campo, Miguel; Nova, Esteban; Salazar, Fabián; Becker, María Inés

2012-03-01

Hemocyanins, which boost the immune system of mammals, have been used as carrier-adjuvants to promote Ab production against haptens and peptides, as immunostimulants during therapy for bladder carcinoma and as a component in therapeutic vaccines for cancer. These biomedical applications have led to growing interest in obtaining hemocyanins with high immunogenicity. Here, we study the immunological properties of a modified oxidized Concholepas concholepas hemocyanin (Ox-CCH) obtained by the oxidation of its carbohydrates using sodium periodate. We assessed the internalization of Ox-CCH into DCs and its immunogenicity and antitumor effects. Transmission electron microscopy showed no changes in Ox-CCH quaternary structure with respect to native CCH, although proteolytic treatment followed by SDS-PAGE analysis demonstrated that Schiff bases were formed. Interestingly, DCs internalized Ox-CCH faster than CCH, mainly through macropinocytosis. During this process, Ox-CCH remained inside endosome-like structures for a longer period. Mouse immunization experiments demonstrated that Ox-CCH is more immunogenic and a better carrier than CCH. Moreover, Ox-CCH showed a significant antitumor effect in the B16F10 melanoma model similar to that produced by CCH, inducing IFN-γ secretion. Together, these data demonstrate that the aldehydes formed by the periodate oxidation of sugar moieties stabilizes the CCH structure, increasing its adjuvant/immunostimulatory carrier effects. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Epitope-Specific Evolution of Human B Cell Responses to Borrelia burgdorferi VlsE Protein from Early to Late Stages of Lyme Disease.

PubMed

Jacek, Elzbieta; Tang, Kevin S; Komorowski, Lars; Ajamian, Mary; Probst, Christian; Stevenson, Brian; Wormser, Gary P; Marques, Adriana R; Alaedini, Armin

2016-02-01

Most immunogenic proteins of Borrelia burgdorferi, the causative agent of Lyme disease, are known or expected to contain multiple B cell epitopes. However, the kinetics of the development of human B cell responses toward the various epitopes of individual proteins during the course of Lyme disease has not been examined. Using the highly immunogenic VlsE as a model Ag, we investigated the evolution of humoral immune responses toward its immunodominant sequences in 90 patients with a range of early to late manifestations of Lyme disease. The results demonstrate the existence of asynchronous, independently developing, Ab responses against the two major immunogenic regions of the VlsE molecule in the human host. Despite their strong immunogenicity, the target epitopes were inaccessible to Abs on intact spirochetes, suggesting a lack of direct immunoprotective effect. These observations document the association of immune reactivity toward specific VlsE sequences with different phases of Lyme disease, demonstrating the potential use of detailed epitope mapping of Ags for staging of the infection, and offer insights regarding the pathogen's possible immune evasion mechanisms. Copyright © 2016 by The American Association of Immunologists, Inc.

Influence of Oxidation and Multimerization on the Immunogenicity of a Thioredoxin-L2 Prophylactic Papillomavirus Vaccine

PubMed Central

Seitz, Hanna; Dantheny, Tatiana; Burkart, Frank; Ottonello, Simone

2013-01-01

Current commercial prophylactic human papillomavirus (HPV) vaccines are based on virus-like particles assembled from the major capsid protein L1 and show excellent safety and efficacy profiles. Still, a major limitation is their rather narrow range of protection against different HPV types. In contrast, the minor capsid protein L2 contains a so-called major cross-neutralizing epitope that can induce broad-range protective responses against multiple HPV types. This epitope is conserved among different papillomaviruses (PV) and contains two cysteine residues that are present in the L2 proteins of all known PV types. The main challenge in developing L2-directed vaccines is to overcome the intrinsically low immunogenicity of the L2 protein. Previously, we developed a recombinant L2-based prototype vaccine by inserting peptide epitopes spanning the cross-neutralizing L2 sequence into a bacterial thioredoxin (Trx) scaffold. These antigens induced high-titer neutralizing antibodies in mice. Here, we address the question of whether Trx scaffold multimerization may further enhance the immunogenicity of the TrxL2 vaccine. We also demonstrate that the oxidation state of the conserved cysteine residues is not essential for vaccine functionality, but it contributes to immunogenicity. PMID:23677323

Cross-reactive and pre-existing antibodies to therapeutic antibodies—Effects on treatment and immunogenicity

PubMed Central

van Schie, Karin A; Wolbink, Gerrit-Jan; Rispens, Theo

2015-01-01

The potential for immunogenicity is an ever-present concern during the development of biopharmaceuticals. Therapeutic antibodies occasionally elicit an antibody response in patients, which can result in loss of response or adverse effects. However, antibodies that bind a drug are sometimes found in pre-treatment serum samples, with the amount depending on drug, assay, and patient population. This review summarizes published data on pre-existing antibodies to therapeutic antibodies, including rheumatoid factors, anti-allotype antibodies, anti-hinge antibodies, and anti-glycan antibodies. Unlike anti-idiotype antibodies elicited by the drug, pre-formed antibodies in general appear to have little consequences during treatment. In the few cases where (potential) clinical consequences were encountered, antibodies were characterized and found to bind a distinct, unusual epitope of the therapeutic. Immunogenicity testing strategies should therefore always include a proper level of antibody characterization, especially when pre-formed antibodies are present. This minimizes false-positives, particularly due to rheumatoid factors, and helps to judge the potential threat in case a genuine pre-dose antibody reactivity is identified. PMID:25962087

The use of a P. falciparum specific coiled-coil domain to construct a self-assembling protein nanoparticle vaccine to prevent malaria.

PubMed

Karch, Christopher P; Doll, Tais A P F; Paulillo, Sara M; Nebie, Issa; Lanar, David E; Corradin, Giampietro; Burkhard, Peter

2017-09-06

The parasitic disease malaria remains a major global public health concern and no truly effective vaccine exists. One approach to the development of a malaria vaccine is to target the asexual blood stage that results in clinical symptoms. Most attempts have failed. New antigens such as P27A and P27 have emerged as potential new vaccine candidates. Multiple studies have demonstrated that antigens are more immunogenic and are better correlated with protection when presented on particulate delivery systems. One such particulate delivery system is the self-assembling protein nanoparticle (SAPN) that relies on coiled-coil domains of proteins to form stable nanoparticles. In the past we have used de novo designed amino acid domains to drive the formation of the coiled-coil scaffolds which present the antigenic epitopes on the particle surface. Here we use naturally occurring domains found in the tex1 protein to form the coiled-coil scaffolding of the nanoparticle. Thus, by engineering P27A and a new extended form of the coiled-coil domain P27 onto the N and C terminus of the SAPN protein monomer we have developed a particulate delivery system that effectively displays both antigens on a single particle that uses malaria tex1 sequences to form the nanoparticle scaffold. These particles are immunogenic in a murine model and induce immune responses similar to the ones observed in seropositive individuals in malaria endemic regions. We demonstrate that our P27/P27A-SAPNs induce an immune response akin to the one in seropositive individuals in Burkina Faso. Since P27 is highly conserved among different Plasmodium species, these novel SAPNs may even provide cross-protection between Plasmodium falciparum and Plasmodium vivax the two major human malaria pathogens. As the SAPNs are also easy to manufacture and store they can be delivered to the population in need without complication thus providing a low cost malaria vaccine.

Randomized phase I trial HIV-CORE 003: Depletion of serum amyloid P component and immunogenicity of DNA vaccination against HIV-1.

PubMed

Borthwick, Nicola J; Lane, Thirusha; Moyo, Nathifa; Crook, Alison; Shim, Jung Min; Baines, Ian; Wee, Edmund G; Hawkins, Philip N; Gillmore, Julian D; Hanke, Tomáš; Pepys, Mark B

2018-01-01

The failure of DNA vaccination in humans, in contrast to its efficacy in some species, is unexplained. Observational and interventional experimental evidence suggests that DNA immunogenicity may be prevented by binding of human serum amyloid P component (SAP). SAP is the single normal DNA binding protein in human plasma. The drug (R)-1-[6-[(R)-2-carboxypyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC, miridesap), developed for treatment of systemic amyloidosis and Alzheimer's disease, depletes circulating SAP by 95-99%. The proof-of-concept HIV-CORE 003 clinical trial tested whether SAP depletion by CPHPC would enhance the immune response in human volunteers to DNA vaccination delivering the HIVconsv immunogen derived from conserved sub-protein regions of HIV-1. Human volunteers received 3 intramuscular immunizations with an experimental DNA vaccine (DDD) expressing HIV-1-derived immunogen HIVconsv, with or without prior depletion of SAP by CPHPC. All subjects were subsequently boosted by simian (chimpanzee) adenovirus (C)- and poxvirus MVA (M)-vectored vaccines delivering the same immunogen. After administration of each vaccine modality, the peak total magnitudes, kinetics, functionality and memory subsets of the T-cell responses to HIVconsv were thoroughly characterized. No differences were observed between the CPHPC treated and control groups in any of the multiple quantitative and qualitative parameters of the T-cell responses to HIVconsv, except that after SAP depletion, there was a statistically significantly greater breadth of T-cell specificities, that is the number of recognized epitopes, following the DDDC vaccination. The protocol used here for SAP depletion by CPHPC prior to DNA vaccination produced only a very modest suggestion of enhanced immunogenicity. Further studies will be required to determine whether SAP depletion might have a practical value in DNA vaccination for other plasmid backbones and/or immunogens. Clinicaltrials.gov NCT02425241.

Ten tandem repeats of {beta}-hCG 109-118 enhance immunogenicity and anti-tumor effects of {beta}-hCG C-terminal peptide carried by mycobacterial heat-shock protein HSP65

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Yankai; Yan Rong; He Yi

2006-07-14

The {beta}-subunit of human chorionic gonadotropin ({beta}-hCG) is secreted by many kinds of tumors and it has been used as an ideal target antigen to develop vaccines against tumors. In view of the low immunogenicity of this self-peptide,we designed a method based on isocaudamer technique to repeat tandemly the 10-residue sequence X of {beta}-hCG (109-118), then 10 tandemly repeated copies of the 10-residue sequence combined with {beta}-hCG C-terminal 37 peptides were fused to mycobacterial heat-shock protein 65 to construct a fusion protein HSP65-X10-{beta}hCGCTP37 as an immunogen. In this study, we examined the effect of the tandem repeats of this 10-residuemore » sequence in eliciting an immune by comparing the immunogenicity and anti-tumor effects of the two immunogens, HSP65-X10-{beta}hCGCTP37 and HSP65-{beta}hCGCTP37 (without the 10 tandem repeats). Immunization of mice with the fusion protein HSP65-X10-{beta}hCGCTP37 elicited much higher levels of specific anti-{beta}-hCG antibodies and more effectively inhibited the growth of Lewis lung carcinoma (LLC) in vivo than with HSP65-{beta}hCGCTP37, which should suggest that HSP65-X10-{beta}hCGCTP37 may be an effective protein vaccine for the treatment of {beta}-hCG-dependent tumors and multiple tandem repeats of a certain epitope are an efficient method to overcome the low immunogenicity of self-peptide antigens.« less

Attenuated Human Parainfluenza Virus Type 1 Expressing the Respiratory Syncytial Virus (RSV) Fusion (F) Glycoprotein from an Added Gene: Effects of Prefusion Stabilization and Packaging of RSV F

PubMed Central

Liu, Xiang; Liang, Bo; Ngwuta, Joan; Liu, Xueqiao; Surman, Sonja; Lingemann, Matthias; Kwong, Peter D.; Graham, Barney S.; Collins, Peter L.

2017-01-01

ABSTRACT Human respiratory syncytial virus (RSV) is the most prevalent worldwide cause of severe respiratory tract infection in infants and young children. Human parainfluenza virus type 1 (HPIV1) also causes severe pediatric respiratory illness, especially croup. Both viruses lack vaccines. Here, we describe the preclinical development of a bivalent RSV/HPIV1 vaccine based on a recombinant HPIV1 vector, attenuated by a stabilized mutation, that expresses RSV F protein modified for increased stability in the prefusion (pre-F) conformation by previously described disulfide bond (DS) and hydrophobic cavity-filling (Cav1) mutations. RSV F was expressed from the first or second gene position as the full-length protein or as a chimeric protein with its transmembrane and cytoplasmic tail (TMCT) domains substituted with those of HPIV1 F in an effort to direct packaging in the vector particles. All constructs were recovered by reverse genetics. The TMCT versions of RSV F were packaged in the rHPIV1 particles much more efficiently than their full-length counterparts. In hamsters, the presence of the RSV F gene, and in particular the TMCT versions, was attenuating and resulted in reduced immunogenicity. However, the vector expressing full-length RSV F from the pre-N position was immunogenic for RSV and HPIV1. It conferred complement-independent high-quality RSV-neutralizing antibodies at titers similar to those of wild-type RSV and provided protection against RSV challenge. The vectors exhibited stable RSV F expression in vitro and in vivo. In conclusion, an attenuated rHPIV1 vector expressing a pre-F-stabilized form of RSV F demonstrated promising immunogenicity and should be further developed as an intranasal pediatric vaccine. IMPORTANCE RSV and HPIV1 are major viral causes of acute pediatric respiratory illness for which no vaccines or suitable antiviral drugs are available. The RSV F glycoprotein is the major RSV neutralization antigen. We used a rHPIV1 vector, bearing a stabilized attenuating mutation, to express the RSV F glycoprotein bearing amino acid substitutions that increase its stability in the pre-F form, the most immunogenic form that elicits highly functional virus-neutralizing antibodies. RSV F was expressed from the pre-N or N-P gene position of the rHPIV1 vector as a full-length protein or as a chimeric form with its TMCT domain derived from HPIV1 F. TMCT modification greatly increased packaging of RSV F into the vector particles but also increased vector attenuation in vivo, resulting in reduced immunogenicity. In contrast, full-length RSV F expressed from the pre-N position was immunogenic, eliciting complement-independent RSV-neutralizing antibodies and providing protection against RSV challenge. PMID:28835504

Engineering filamentous phage carriers to improve focusing of antibody responses against peptides.

PubMed

van Houten, Nienke E; Henry, Kevin A; Smith, George P; Scott, Jamie K

2010-03-02

The filamentous bacteriophage are highly immunogenic particles that can be used as carrier proteins for peptides and presumably other haptens and antigens. Our previous work demonstrated that the antibody response was better focused against a synthetic peptide if it was conjugated to phage as compared to the classical carrier, ovalbumin. We speculated that this was due, in part, to the relatively low surface complexity of the phage. Here, we further investigate the phage as an immunogenic carrier, and the effect reducing its surface complexity has on the antibody response against peptides that are either displayed as recombinant fusions to the phage coat or are chemically conjugated to it. Immunodominant regions of the minor coat protein, pIII, were removed from the phage surface by excising its N1 and N2 domains (Delta3 phage variant), whereas immunodominant epitopes of the major coat protein, pVIII, were altered by reducing the charge of its surface-exposed N-terminal residues (Delta8 phage variant). Immunization of mice revealed that the Delta3 variant was less immunogenic than wild-type (WT) phage, whereas the Delta8 variant was more immunogenic. The immunogenicity of two different peptides was tested in the context of the WT and Delta3 phage in two different forms: (i) as recombinant peptides fused to pVIII, and (ii) as synthetic peptides conjugated to the phage surface. One peptide (MD10) in its recombinant form produced a stronger anti-peptide antibody response fused to the WT carrier compared to the Delta3 phage carrier, and did not elicit a detectable anti-peptide response in its synthetic form conjugated to either phage carrier. This trend was reversed for a different peptide (4E10(L)), which did not produce a detectable anti-peptide antibody response as a recombinant fusion; yet, as a chemical conjugate to Delta3 phage, but not WT phage, it elicited a highly focused anti-peptide antibody response that exceeded the anti-carrier response by approximately 65-fold. The results suggest that focusing of the antibody response against synthetic peptides can be improved by decreasing the antigenic complexity of the phage surface. Copyright 2010 Elsevier Ltd. All rights reserved.

Accurate structure prediction of peptide–MHC complexes for identifying highly immunogenic antigens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Min-Sun; Park, Sung Yong; Miller, Keith R.

2013-11-01

Designing an optimal HIV-1 vaccine faces the challenge of identifying antigens that induce a broad immune capacity. One factor to control the breadth of T cell responses is the surface morphology of a peptide–MHC complex. Here, we present an in silico protocol for predicting peptide–MHC structure. A robust signature of a conformational transition was identified during all-atom molecular dynamics, which results in a model with high accuracy. A large test set was used in constructing our protocol and we went another step further using a blind test with a wild-type peptide and two highly immunogenic mutants, which predicted substantial conformationalmore » changes in both mutants. The center residues at position five of the analogs were configured to be accessible to solvent, forming a prominent surface, while the residue of the wild-type peptide was to point laterally toward the side of the binding cleft. We then experimentally determined the structures of the blind test set, using high resolution of X-ray crystallography, which verified predicted conformational changes. Our observation strongly supports a positive association of the surface morphology of a peptide–MHC complex to its immunogenicity. Our study offers the prospect of enhancing immunogenicity of vaccines by identifying MHC binding immunogens.« less

Native-like aggregates of Factor VIII (FVIII) are immunogenic von Willebrand Factor deficient and hemophilia A mice

PubMed Central

Pisal, Dipak S.; Kosloski, Matthew P.; Middaugh, C. Russell; Bankert, Richard B.; Balu-Iyer, Sathy V.

2013-01-01

The administration of recombinant Factor VIII (FVIII) is the first line therapy for Hemophilia A (HA), but 25–35% of patients develop an inhibitory antibody response. In general, the presence of aggregates contributes to unwanted immunogenic responses against therapeutic proteins. FVIII has been shown to form both native-like and non-native aggregates. Previously, we showed that non-native aggregates of FVIII are less immunogenic compared to the native protein. Here we investigated the effect of native-like aggregates of FVIII on immunogenicity in HA and von Willebrand Factor knockout (vWF−/−) mice. Mice immunized with native-like aggregates showed significantly higher inhibitory antibody titers compared to animals that received native FVIII. Following re-stimulation in vitro with native FVIII, the activation of CD4+ T cells isolated from mice immunized with native-like aggregates is ~4 fold higher than mice immunized with the native protein. Furthermore, this is associated with increases in the secretion of pro-inflammatory cytokines IL-6 and IL-17 in the native-like aggregate treatment group. The results indicate that the native-like aggregates of FVIII are more immunogenic than native FVIII for both the B cell and T cell responses. PMID:22388918

Expression and immunogenicity of novel subunit enterovirus 71 VP1 antigens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Juan; Department of Microbiology and Immunology, Nanjing Medical University; Wang, Shixia

Highlights: Black-Right-Pointing-Pointer EV71 is a major emerging infectious disease in many Asian countries. Black-Right-Pointing-Pointer Inactivated EV71 vaccines are in clinical studies but their safety and efficacy are unknown. Black-Right-Pointing-Pointer Developing subunit based EV71 vaccines is significant and novel antigen design is needed. Black-Right-Pointing-Pointer DNA immunization is an efficient tool to test the immunogenicity of VP1 based EV71 vaccines. Black-Right-Pointing-Pointer Multiple VP1 antigens are developed showing immunogenic potential. -- Abstract: Hand, foot, and mouth disease (HFMD) is a common viral illness in young children. HFMD is caused by viruses belonging to the enterovirus genus of the picornavirus family. Recently, enterovirus 71more » (EV71) has emerged as a virulent agent for HFMD with severe clinical outcomes. In the current report, we conducted a pilot antigen engineering study to optimize the expression and immunogenicity of subunit VP1 antigen for the design of EV71 vaccines. DNA immunization was adopted as a simple technical approach to test different designs of VP1 antigens without the need to express VP1 protein in vitro first. Our studies indicated that the expression and immunogenicity of VP1 protein can be improved with alternated VP1 antigen designs. Data presented in the current report revealed novel pathways to optimize the design of VP1 antigen-based EV71 vaccines.« less

Group A Streptococcal vaccine candidate: contribution of epitope to size, antigen presenting cell interaction and immunogenicity.

PubMed

Zaman, Mehfuz; Chandrudu, Saranya; Giddam, Ashwini K; Reiman, Jennifer; Skwarczynski, Mariusz; McPhun, Virginia; Moyle, Peter M; Batzloff, Michael R; Good, Michael F; Toth, Istvan

2014-12-01

Utilize lipopeptide vaccine delivery system to develop a vaccine candidate against Group A Streptococcus. Lipopeptides synthesized by solid-phase peptide synthesis-bearing carboxyl (C)-terminal and amino (N)-terminal Group A Streptococcus peptide epitopes. Nanoparticles formed were evaluated in vivo. Immune responses were induced in mice without additional adjuvant. We demonstrated for the first time that incorporation of the C-terminal epitope significantly enhanced the N-terminal epitope-specific antibody response and correlated with forming smaller nanoparticles. Antigen-presenting cells had increased uptake and maturation by smaller, more immunogenic nanoparticles. Antibodies raised by vaccination recognized isolates. Demonstrated the lipopeptidic nanoparticles to induce an immune response which can be influenced by the combined effect of epitope choice and size.

Intrinsic immunogenicity of rapidly-degradable polymers evolves during degradation.

PubMed

Andorko, James I; Hess, Krystina L; Pineault, Kevin G; Jewell, Christopher M

2016-03-01

Recent studies reveal many biomaterial vaccine carriers are able to activate immunostimulatory pathways, even in the absence of other immune signals. How the changing properties of polymers during biodegradation impact this intrinsic immunogenicity is not well studied, yet this information could contribute to rational design of degradable vaccine carriers that help direct immune response. We use degradable poly(beta-amino esters) (PBAEs) to explore intrinsic immunogenicity as a function of the degree of polymer degradation and polymer form (e.g., soluble, particles). PBAE particles condensed by electrostatic interaction to mimic a common vaccine approach strongly activate dendritic cells, drive antigen presentation, and enhance T cell proliferation in the presence of antigen. Polymer molecular weight strongly influences these effects, with maximum stimulation at short degradation times--corresponding to high molecular weight--and waning levels as degradation continues. In contrast, free polymer is immunologically inert. In mice, PBAE particles increase the numbers and activation state of cells in lymph nodes. Mechanistic studies reveal that this evolving immunogenicity occurs as the physicochemical properties and concentration of particles change during polymer degradation. This work confirms the immunological profile of degradable, synthetic polymers can evolve over time and creates an opportunity to leverage this feature in new vaccines. Degradable polymers are increasingly important in vaccination, but how the inherent immunogenicity of polymers changes during degradation is poorly understood. Using common rapidly-degradable vaccine carriers, we show that the activation of immune cells--even in the absence of other adjuvants--depends on polymer form (e.g., free, particulate) and the extent of degradation. These changing characteristics alter the physicochemical properties (e.g., charge, size, molecular weight) of polymer particles, driving changes in immunogenicity. Our results are important as many common biomaterials (e.g., PLGA) are now known to exhibit immune activity that alters how vaccines are processed. Thus, the results of this study could contribute to more rational design of biomaterial carriers that also actively direct the properties of responses generated by vaccines. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Hydroxyl Radical Modification of Collagen Type II Increases Its Arthritogenicity and Immunogenicity

PubMed Central

Shahab, Uzma; Ahmad, Saheem; Moinuddin; Dixit, Kiran; Habib, Safia; Alam, Khursheed; Ali, Asif

2012-01-01

Background The oxidation of proteins by endogenously generated free radicals causes structural modifications in the molecules that lead to generation of neo-antigenic epitopes that have implications in various autoimmune disorders, including rheumatoid arthritis (RA). Collagen induced arthritis (CIA) in rodents (rats and mice) is an accepted experimental model for RA. Methodology/Principal Findings Hydroxyl radicals were generated by the Fenton reaction. Collagen type II (CII) was modified by •OH radical (CII-OH) and analysed by ultraviolet-visible (UV-VIS), fluorescence and circular dichroism (CD) spectroscopy. The immunogenicity of native and modified CII was checked in female Lewis rats and specificity of the induced antibodies was ascertained by enzyme linked immunosorbent assay (ELISA). The extent of CIA was evaluated by visual inspection. We also estimated the oxidative and inflammatory markers in the sera of immunized rats. A slight change in the triple helical structure of CII as well as fragmentation was observed after hydroxyl radical modification. The modified CII was found to be highly arthritogenic and immunogenic as compared to the native form. The CII-OH immunized rats exhibited increased oxidative stress and inflammation as compared to the CII immunized rats in the control group. Conclusions/Significance Neo-antigenic epitopes were generated on •OH modified CII which rendered it highly immunogenic and arthritogenic as compared to the unmodified form. Since the rodent CIA model shares many features with human RA, these results illuminate the role of free radicals in human RA. PMID:22319617

Tracing evolutionary relicts of positive selection on eight malaria-related immune genes in mammals.

PubMed

Huang, Bing-Hong; Liao, Pei-Chun

2015-07-01

Plasmodium-induced malaria widely infects primates and other mammals. Multiple past studies have revealed that positive selection could be the main evolutionary force triggering the genetic diversity of anti-malaria resistance-associated genes in human or primates. However, researchers focused most of their attention on the infra-generic and intra-specific genome evolution rather than analyzing the complete evolutionary history of mammals. Here we extend previous research by testing the evolutionary link of natural selection on eight candidate genes associated with malaria resistance in mammals. Three of the eight genes were detected to be affected by recombination, including TNF-α, iNOS and DARC. Positive selection was detected in the rest five immunogenes multiple times in different ancestral lineages of extant species throughout the mammalian evolution. Signals of positive selection were exposed in four malaria-related immunogenes in primates: CCL2, IL-10, HO1 and CD36. However, selection signals of G6PD have only been detected in non-primate eutherians. Significantly higher evolutionary rates and more radical amino acid replacement were also detected in primate CD36, suggesting its functional divergence from other eutherians. Prevalent positive selection throughout the evolutionary trajectory of mammalian malaria-related genes supports the arms race evolutionary hypothesis of host genetic response of mammalian immunogenes to infectious pathogens. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

In situ vaccination with cowpea mosaic virus nanoparticles suppresses metastatic cancer

NASA Astrophysics Data System (ADS)

Lizotte, P. H.; Wen, A. M.; Sheen, M. R.; Fields, J.; Rojanasopondist, P.; Steinmetz, N. F.; Fiering, S.

2016-03-01

Nanotechnology has tremendous potential to contribute to cancer immunotherapy. The ‘in situ vaccination’ immunotherapy strategy directly manipulates identified tumours to overcome local tumour-mediated immunosuppression and subsequently stimulates systemic antitumour immunity to treat metastases. We show that inhalation of self-assembling virus-like nanoparticles from cowpea mosaic virus (CPMV) reduces established B16F10 lung melanoma and simultaneously generates potent systemic antitumour immunity against poorly immunogenic B16F10 in the skin. Full efficacy required Il-12, Ifn-γ, adaptive immunity and neutrophils. Inhaled CPMV nanoparticles were rapidly taken up by and activated neutrophils in the tumour microenvironment as an important part of the antitumour immune response. CPMV also exhibited clear treatment efficacy and systemic antitumour immunity in ovarian, colon, and breast tumour models in multiple anatomic locations. CPMV nanoparticles are stable, nontoxic, modifiable with drugs and antigens, and their nanomanufacture is highly scalable. These properties, combined with their inherent immunogenicity and demonstrated efficacy against a poorly immunogenic tumour, make CPMV an attractive and novel immunotherapy against metastatic cancer.

Technology evaluation: C242-DM1, ImmunoGen Inc.

PubMed

Smith, S

2001-04-01

C242-DM1 is a tumor-activated immunotoxin under development by GlaxoSmithKline plc (formerly SmithKline Beecham plc), under licence from ImmunoGen Inc, as a potential treatment for colon tumor. It consists of a colon cancer-specific humanized antibody, C242, conjugated to the maytansine derivative DM1. In preclinical studies, C242-DM1 caused complete tumor regression in animal models of both human pancreatic and non-small cell lung cancer (NSCLC) at non-toxic doses. C242-DM1 has also been evaluated in an immunoconjugate combination with J-591 (Cornell University). The J591-DM1 immunoconjugate demonstrated effective, antigen-specific delivery of a highly cytotoxic drug to PSMA-positive Pca cells in vitro and in vivo with low systemic toxicity. Results from studies in monkeys showed that C242-DM1 had no significant toxicity or side effects, when administered at doses higher than those that were previously shown to completely eradicate human colon tumors in mice [271420]. ImmunoGen acquired the right to evaluate, and an option to license, technology related to maytansines from Takeda. In February 1999, ImmunoGen and SmithKline Beecham signed a US $45 million development and commercialization agreement for C242-DM1 [313493]. In August 1997, Immunogen received an SBIR grant to advance development of huC242-DM1 [258356]. EP-00425235, held by ImmunoGen, covers conjugated forms of ansamitocin (maytansine) derivatives. Takeda holds several patents for the production of ansamitocin and its analogs, the first one being JP-53124692.

Attenuated Human Parainfluenza Virus Type 1 Expressing the Respiratory Syncytial Virus (RSV) Fusion (F) Glycoprotein from an Added Gene: Effects of Prefusion Stabilization and Packaging of RSV F.

PubMed

Liu, Xiang; Liang, Bo; Ngwuta, Joan; Liu, Xueqiao; Surman, Sonja; Lingemann, Matthias; Kwong, Peter D; Graham, Barney S; Collins, Peter L; Munir, Shirin

2017-11-15

Human respiratory syncytial virus (RSV) is the most prevalent worldwide cause of severe respiratory tract infection in infants and young children. Human parainfluenza virus type 1 (HPIV1) also causes severe pediatric respiratory illness, especially croup. Both viruses lack vaccines. Here, we describe the preclinical development of a bivalent RSV/HPIV1 vaccine based on a recombinant HPIV1 vector, attenuated by a stabilized mutation, that expresses RSV F protein modified for increased stability in the prefusion (pre-F) conformation by previously described disulfide bond (DS) and hydrophobic cavity-filling (Cav1) mutations. RSV F was expressed from the first or second gene position as the full-length protein or as a chimeric protein with its transmembrane and cytoplasmic tail (TMCT) domains substituted with those of HPIV1 F in an effort to direct packaging in the vector particles. All constructs were recovered by reverse genetics. The TMCT versions of RSV F were packaged in the rHPIV1 particles much more efficiently than their full-length counterparts. In hamsters, the presence of the RSV F gene, and in particular the TMCT versions, was attenuating and resulted in reduced immunogenicity. However, the vector expressing full-length RSV F from the pre-N position was immunogenic for RSV and HPIV1. It conferred complement-independent high-quality RSV-neutralizing antibodies at titers similar to those of wild-type RSV and provided protection against RSV challenge. The vectors exhibited stable RSV F expression in vitro and in vivo In conclusion, an attenuated rHPIV1 vector expressing a pre-F-stabilized form of RSV F demonstrated promising immunogenicity and should be further developed as an intranasal pediatric vaccine. IMPORTANCE RSV and HPIV1 are major viral causes of acute pediatric respiratory illness for which no vaccines or suitable antiviral drugs are available. The RSV F glycoprotein is the major RSV neutralization antigen. We used a rHPIV1 vector, bearing a stabilized attenuating mutation, to express the RSV F glycoprotein bearing amino acid substitutions that increase its stability in the pre-F form, the most immunogenic form that elicits highly functional virus-neutralizing antibodies. RSV F was expressed from the pre-N or N-P gene position of the rHPIV1 vector as a full-length protein or as a chimeric form with its TMCT domain derived from HPIV1 F. TMCT modification greatly increased packaging of RSV F into the vector particles but also increased vector attenuation in vivo , resulting in reduced immunogenicity. In contrast, full-length RSV F expressed from the pre-N position was immunogenic, eliciting complement-independent RSV-neutralizing antibodies and providing protection against RSV challenge. Copyright © 2017 American Society for Microbiology.

Immunogenic cancer cell death selectively induced by near infrared photoimmunotherapy initiates host tumor immunity.

PubMed

Ogawa, Mikako; Tomita, Yusuke; Nakamura, Yuko; Lee, Min-Jung; Lee, Sunmin; Tomita, Saori; Nagaya, Tadanobu; Sato, Kazuhide; Yamauchi, Toyohiko; Iwai, Hidenao; Kumar, Abhishek; Haystead, Timothy; Shroff, Hari; Choyke, Peter L; Trepel, Jane B; Kobayashi, Hisataka

2017-02-07

Immunogenic cell death (ICD) is a form of cell death that activates an adaptive immune response against dead-cell-associated antigens. Cancer cells killed via ICD can elicit antitumor immunity. ICD is efficiently induced by near-infrared photo-immunotherapy (NIR-PIT) that selectively kills target-cells on which antibody-photoabsorber conjugates bind and are activated by NIR light exposure. Advanced live cell microscopies showed that NIR-PIT caused rapid and irreversible damage to the cell membrane function leading to swelling and bursting, releasing intracellular components due to the influx of water into the cell. The process also induces relocation of ICD bio markers including calreticulin, Hsp70 and Hsp90 to the cell surface and the rapid release of immunogenic signals including ATP and HMGB1 followed by maturation of immature dendritic cells. Thus, NIR-PIT is a therapy that kills tumor cells by ICD, eliciting a host immune response against tumor.

Trial Watch: Immunogenic cell death inducers for anticancer chemotherapy.

PubMed

Pol, Jonathan; Vacchelli, Erika; Aranda, Fernando; Castoldi, Francesca; Eggermont, Alexander; Cremer, Isabelle; Sautès-Fridman, Catherine; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2015-04-01

The term "immunogenic cell death" (ICD) is now employed to indicate a functionally peculiar form of apoptosis that is sufficient for immunocompetent hosts to mount an adaptive immune response against dead cell-associated antigens. Several drugs have been ascribed with the ability to provoke ICD when employed as standalone therapeutic interventions. These include various chemotherapeutics routinely employed in the clinic (e.g., doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin) as well as some anticancer agents that are still under preclinical or clinical development (e.g., some microtubular inhibitors of the epothilone family). In addition, a few drugs are able to convert otherwise non-immunogenic instances of cell death into bona fide ICD, and may therefore be employed as chemotherapeutic adjuvants within combinatorial regimens. This is the case of cardiac glycosides, like digoxin and digitoxin, and zoledronic acid. Here, we discuss recent developments on anticancer chemotherapy based on ICD inducers.

Improved osteogenesis and upregulated immunogenicity in human placenta-derived mesenchymal stem cells primed with osteogenic induction medium.

PubMed

Fu, Xuejie; Yang, Huilin; Zhang, Hui; Wang, Guichao; Liu, Ke; Gu, Qiaoli; Tao, Yunxia; Chen, Guangcun; Jiang, Xiaohua; Li, Gang; Gu, Yanzheng; Shi, Qin

2016-09-20

Mesenchymal stem cells (MSCs) are widely used in cell-based therapy owing to their multilineage potential and low immunogenicity. However, low differentiation efficiency and unpredictable immunogenicity of allogeneic MSCs in vivo limit their success in therapeutic treatment. Herein, we evaluated the differentiation potential and immunogenicity of human placenta-derived MSCs manipulated with osteogenic priming and dedifferentiation process. MSCs from human placentas were subjected to osteogenic induction and then cultivated in osteogenic factor-free media; the obtained cell population was termed dedifferentiated mesenchymal stem cells (De-MSCs). De-MSCs were induced into osteo-, chondro- and adipo-differentiation in vitro. Cell proliferation was quantified by a Cell-Counting Kit-8 or tritiated thymidine ([(3)H]-TdR) incorporation. Meanwhile, the osteogenesis of De-MSCs in vivo was assayed by real-time PCR and histological staining. The expressions of stem cell markers and co-stimulatory molecules on De-MSCs and lymphocytes from primed BALB/c mouse with De-MSCs were determined by flow cytometry. De-MSCs exhibited some properties similar to MSCs including multiple differentiation potential and hypoimmunogenicity. Upon re-osteogenic induction, De-MSCs exhibited higher differentiation capability than MSCs both in vitro and in vivo. Of note, De-MSCs had upregulated immunogenicity in association with their osteogenesis, reflected by the alternated expressions of co-stimulatory molecules on the surface and decreased suppression on T cell activation. Functionally, De-MSC-derived osteoblasts could prime lymphocytes of peripheral blood and spleen in BALB/c mice in vivo. These data are of great significance for the potential application of De-MSCs as an alternative resource for regenerative medicine and tissue engineering. In order to avoid being rejected by the host during allogeneic De-MSC therapy, we suggest that immune intervention should be considered to boost the immune acceptance and integration because of the upregulated immunogenicity of De-MSCs with redifferentiation in clinical applications.

Phase 3 randomised study of the proposed biosimilar adalimumab GP2017 in psoriasis - impact of multiple switches.

PubMed

Blauvelt, A; Lacour, J-P; Fowler, J F; Weinberg, J M; Gospodinov, D; Schuck, E; Jauch-Lembach, J; Balfour, A; Leonardi, C L

2018-06-19

The impact of multiple switches between GP2017 and reference adalimumab (ref-ADMB) was assessed following the demonstration of equivalent efficacy and similar safety and immunogenicity, in adult patients with active, clinically stable, moderate-to-severe plaque psoriasis. This 51-week double-blinded, phase 3 study randomly assigned patients to GP2017 (N=231) or ref-ADMB (N=234) 80 mg subcutaneously at Week 0, then 40 mg biweekly from Week 1. At Week 17, patients were re-randomised to switch (n=126) or continue (n=253) treatment. Primary endpoint: patients achieving Psoriasis Area and Severity Index (PASI)75 at Week 16 (equivalence confirmed if the 95% confidence interval [CI] for the difference in PASI75 between treatments was ±18%). Key secondary endpoint: change from baseline to Week 16 in continuous PASI. Other endpoints: PASI over time, PASI 50/75/90/100, pharmacokinetics, safety, tolerability and immunogenicity for the switched and continued treatment groups. Equivalent efficacy between GP2017 and ref-ADMB was confirmed for the primary (66.8% and 65.0%, respectively; 95% CI, -7.46, 11.15) and key secondary (-60.7% and -61.5%, respectively; 95% CI, -3.15, 4.84) endpoints. PASI improved over time and was similar between treatment groups at Week 16, and the switched/continued groups from Weeks 17-51. There were no relevant safety or immunogenicity differences between GP2017 and ref-ADMB at Week 16, or the switched/continued groups from Weeks 17-51. No hypersensitivity to adalimumab was reported upon switching. Following the demonstration of GP2017 biosimilarity to ref-ADMB, switching up to four times between GP2017 and ref-ADMB had no detectable impact on efficacy, safety or immunogenicity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

A prophylactic multivalent vaccine against different filovirus species is immunogenic and provides protection from lethal infections with Ebolavirus and Marburgvirus species in non-human primates.

PubMed

Callendret, Benoit; Vellinga, Jort; Wunderlich, Kerstin; Rodriguez, Ariane; Steigerwald, Robin; Dirmeier, Ulrike; Cheminay, Cedric; Volkmann, Ariane; Brasel, Trevor; Carrion, Ricardo; Giavedoni, Luis D; Patterson, Jean L; Mire, Chad E; Geisbert, Thomas W; Hooper, Jay W; Weijtens, Mo; Hartkoorn-Pasma, Jutta; Custers, Jerome; Grazia Pau, Maria; Schuitemaker, Hanneke; Zahn, Roland

2018-01-01

The search for a universal filovirus vaccine that provides protection against multiple filovirus species has been prompted by sporadic but highly lethal outbreaks of Ebolavirus and Marburgvirus infections. A good prophylactic vaccine should be able to provide protection to all known filovirus species and as an upside potentially protect from newly emerging virus strains. We investigated the immunogenicity and protection elicited by multivalent vaccines expressing glycoproteins (GP) from Ebola virus (EBOV), Sudan virus (SUDV), Taï Forest virus (TAFV) and Marburg virus (MARV). Immune responses against filovirus GP have been associated with protection from disease. The GP antigens were expressed by adenovirus serotypes 26 and 35 (Ad26 and Ad35) and modified Vaccinia virus Ankara (MVA) vectors, all selected for their strong immunogenicity and good safety profile. Using fully lethal NHP intramuscular challenge models, we assessed different vaccination regimens for immunogenicity and protection from filovirus disease. Heterologous multivalent Ad26-Ad35 prime-boost vaccination regimens could give full protection against MARV (range 75%-100% protection) and EBOV (range 50% to 100%) challenge, and partial protection (75%) against SUDV challenge. Heterologous multivalent Ad26-MVA prime-boost immunization gave full protection against EBOV challenge in a small cohort study. The use of such multivalent vaccines did not show overt immune interference in comparison with monovalent vaccines. Multivalent vaccines induced GP-specific antibody responses and cellular IFNγ responses to each GP expressed by the vaccine, and cross-reactivity to TAFV GP was detected in a trivalent vaccine expressing GP from EBOV, SUDV and MARV. In the EBOV challenge studies, higher humoral EBOV GP-specific immune responses (p = 0.0004) were associated with survival from EBOV challenge and less so for cellular immune responses (p = 0.0320). These results demonstrate that it is feasible to generate a multivalent filovirus vaccine that can protect against lethal infection by multiple members of the filovirus family.

A prophylactic multivalent vaccine against different filovirus species is immunogenic and provides protection from lethal infections with Ebolavirus and Marburgvirus species in non-human primates

PubMed Central

Callendret, Benoit; Vellinga, Jort; Wunderlich, Kerstin; Steigerwald, Robin; Dirmeier, Ulrike; Cheminay, Cedric; Volkmann, Ariane; Brasel, Trevor; Carrion, Ricardo; Giavedoni, Luis D.; Patterson, Jean L.; Mire, Chad E.; Geisbert, Thomas W.; Hooper, Jay W.; Weijtens, Mo; Hartkoorn-Pasma, Jutta; Custers, Jerome; Grazia Pau, Maria; Schuitemaker, Hanneke

2018-01-01

The search for a universal filovirus vaccine that provides protection against multiple filovirus species has been prompted by sporadic but highly lethal outbreaks of Ebolavirus and Marburgvirus infections. A good prophylactic vaccine should be able to provide protection to all known filovirus species and as an upside potentially protect from newly emerging virus strains. We investigated the immunogenicity and protection elicited by multivalent vaccines expressing glycoproteins (GP) from Ebola virus (EBOV), Sudan virus (SUDV), Taï Forest virus (TAFV) and Marburg virus (MARV). Immune responses against filovirus GP have been associated with protection from disease. The GP antigens were expressed by adenovirus serotypes 26 and 35 (Ad26 and Ad35) and modified Vaccinia virus Ankara (MVA) vectors, all selected for their strong immunogenicity and good safety profile. Using fully lethal NHP intramuscular challenge models, we assessed different vaccination regimens for immunogenicity and protection from filovirus disease. Heterologous multivalent Ad26-Ad35 prime-boost vaccination regimens could give full protection against MARV (range 75%-100% protection) and EBOV (range 50% to 100%) challenge, and partial protection (75%) against SUDV challenge. Heterologous multivalent Ad26-MVA prime-boost immunization gave full protection against EBOV challenge in a small cohort study. The use of such multivalent vaccines did not show overt immune interference in comparison with monovalent vaccines. Multivalent vaccines induced GP-specific antibody responses and cellular IFNγ responses to each GP expressed by the vaccine, and cross-reactivity to TAFV GP was detected in a trivalent vaccine expressing GP from EBOV, SUDV and MARV. In the EBOV challenge studies, higher humoral EBOV GP-specific immune responses (p = 0.0004) were associated with survival from EBOV challenge and less so for cellular immune responses (p = 0.0320). These results demonstrate that it is feasible to generate a multivalent filovirus vaccine that can protect against lethal infection by multiple members of the filovirus family. PMID:29462200

Dengue envelope-based 'four-in-one' virus-like particles produced using Pichia pastoris induce enhancement-lacking, domain III-directed tetravalent neutralising antibodies in mice.

PubMed

Rajpoot, Ravi Kant; Shukla, Rahul; Arora, Upasana; Swaminathan, Sathyamangalam; Khanna, Navin

2018-06-05

Dengue is a significant public health problem worldwide, caused by four antigenically distinct mosquito-borne dengue virus (DENV) serotypes. Antibodies to any given DENV serotype which can afford protection against that serotype tend to enhance infection by other DENV serotypes, by a phenomenon termed antibody-dependent enhancement (ADE). Antibodies to the viral pre-membrane (prM) protein have been implicated in ADE. We show that co-expression of the envelope protein of all four DENV serotypes, in the yeast Pichia pastoris, leads to their co-assembly, in the absence of prM, into tetravalent mosaic VLPs (T-mVLPs), which retain the serotype-specific antigenic integrity and immunogenicity of all four types of their monomeric precursors. Following a three-dose immunisation schedule, the T-mVLPs elicited EDIII-directed antibodies in mice which could neutralise all four DENV serotypes. Importantly, anti-T-mVLP antibodies did not augment sub-lethal DENV-2 infection of dengue-sensitive AG129 mice, based on multiple parameters. The 'four-in-one' tetravalent T-mVLPs possess multiple desirable features which may potentially contribute to safety (non-viral, prM-lacking and ADE potential-lacking), immunogenicity (induction of virus-neutralising antibodies), and low cost (single tetravalent immunogen produced using P. pastoris, an expression system known for its high productivity using simple inexpensive media). These results strongly warrant further exploration of this vaccine candidate.

Heterogeneity in the A33 protein impacts the cross-protective efficacy of a candidate smallpox DNA vaccine.

PubMed

Golden, Joseph W; Hooper, Jay W

2008-07-20

We previously developed a gene-based vaccine, termed 4pox, which targets four orthopoxvirus proteins (A33, L1, B5, and A27). Because any subunit orthopoxvirus vaccine must protect against multiple species of orthopoxviruses, we are interested in understanding the cross-protective potential of our 4pox vaccine target immunogens. In our current studies, we focused on the A33 immunogen. We found one monoclonal antibody against A33, MAb-1G10, which could not bind the monkeypox virus A33 ortholog, A35. MAb-1G10 binding could be rescued if A35 amino acids 118 and 120 were substituted with those from A33. MAb-1G10 has been shown to protect mice from VACV challenge, thus our findings indicated a protective epitope differs among orthopoxviruses. Accordingly, we tested the cross-protective efficacy of a DNA vaccine consisting of A35R against VACV challenge and compared it to vaccination with A33R DNA. Mice vaccinated with A35R had greater mortality and more weight loss compared to those vaccinated with A33R. These findings demonstrate that despite high homology between A33R orthologs, amino acid differences can impact cross-protection. Furthermore, our results caution that adequate cross-protection by any pan-orthopoxvirus subunit vaccine will require not only careful evaluation of cross-protective immunity, but also of targeting of multiple orthopoxvirus immunogens.

Immunoproteomics Approach for Screening of Vaccine Candidates against Intestinal Botulism.

PubMed

Sharma, Arti; Rani, Sarita; Alam, Syed Imteyaz; Ponmariappan, Sarkaraisamy

2017-01-01

Intestinal botulism is an infectious form of botulism in which disease results from ingesting spores, which is followed by spore germination and intraluminal production of botulinum neurotoxins over an extended period. Botulinum neurotoxin is produced by endospore forming bacteria called C. botulinum. Immunoproteomic study was used to screen the cross reactive immunogenic proteins of Clostridium botulinum type B using C. botulinum type B live spore antiserum. The whole cell proteins were separated by two dimensional gel electrophoresis and transferred to polyvinylidene difluoride membranes. Further, the Western blotting was performed with mouse pups immune serum against C. botulinum type B live spores. Eight predominant cross immunoreactive proteins were identified by mass spectrometry. These immunogenic proteins might be used to develop novel subunit vaccine candidates against the intestinal botulism. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A Novel Immunogenic Spore Coat-Associated Protein in Bacillus Anthracis: Characterization via Proteomics Approaches and a Vector-Based Vaccine System

PubMed Central

Liu, Yu-Tsueng; Lin, Shwu-Bin; Huang, Cheng-Po; Huang, Chun-Ming

2007-01-01

New generation anthrax vaccines have been actively explored with the aim of enhancing efficacies and decreasing undesirable side effects that could be caused by licensed vaccines. Targeting novel antigens and/or eliminating the requirements for multiple needle injections and adjuvants are major objectives in the development of new anthrax vaccines. Using proteomics approaches, we identified a spore coat-associated protein (SCAP) in Bacillus anthracis. An E. coli vector-based vaccine system was used to determine the immunogenicity of SCAP. Mice generated detectable SCAP antibodies three weeks after intranasal immunization with an intact particle of ultraviolet (UV)-irradiated E. coli vector overproducing SCAP. The production of SCAP antibodies was detected via western blotting and SCAP-spotted antigen-arrays. The adjuvant effect of a UV-irradiated E. coli vector eliminates the necessity of boosting and the use of other immunomodulators which will foster the screening and manufacturing of new generation anthrax vaccines. More importantly, the immunogenic SCAP may potentially be a new candidate for the development of anthrax vaccines. PMID:18029197

Rationale for immune-based therapies in Merkel polyomavirus-positive and -negative Merkel cell carcinomas.

PubMed

Vandeven, Natalie; Nghiem, Paul

2016-07-01

Merkel cell carcinoma (MCC) is a rare but often deadly skin cancer that is typically caused by the Merkel cell polyomavirus (MCPyV). Polyomavirus T-antigen oncoproteins are persistently expressed in virus-positive MCCs (˜80% of cases), while remarkably high numbers of tumor-associated neoantigens are detected in virus-negative MCCs, suggesting that both MCC subsets may be immunogenic. Here we review mechanisms by which these immunogenic tumors evade multiple levels of host immunity. Additionally, we summarize the exciting potential of diverse immune-based approaches to treat MCC. In particular, agents blocking the PD-1 axis have yielded strikingly high response rates in MCC as compared with other solid tumors, highlighting the potential for immune-mediated treatment of this disease.

Critical review: assessment of interferon-β immunogenicity in multiple sclerosis.

PubMed

Bendtzen, Klaus

2010-10-01

This review discusses type I interferon (IFN) immunogenicity with focus on methods of detection of anti-IFN antibodies in patients treated with human recombinant IFN-β. Pitfalls involved in the clinical use of various types of assays for binding antibodies and neutralizing antibodies against IFN-β are presented, and the widely held distinction between binding antibodies and neutralizing antibodies is questioned both in terms of detection and clinical importance. The article also addresses important bioavailability and pharmacokinetic issues occurring with prolonged use of protein drugs. The rationale for individualized or personalized medicine, ie, optimizing therapies according to individual needs rather than using standardized trial-and-error regimens to all patients, is highlighted.

T7 phage displaying latent membrane protein 1 of Epstein-Barr virus elicits humoral and cellular immune responses in rats.

PubMed

Gao, J; Liu, Z; Huang, M; Li, X; Wang, Z

2011-01-01

The latent membrane protein 1 (LMP1) encoded by Epstein-Barr virus (EBV) has become a potential target in EBV-associated tumor prevention and treatment due to its multiple biological effects. In this study, the recombinant T7 phage displaying full-length LMP1 protein was cloned and used as an immunogen to immunize rats. Results of flow cytometry, Western blot analysis, and ELISA confirmed that both humoral and cellular immune responses were elicited in the immunized rats. Our data suggested that T7 phage was an efficient antigen carrier. The recombinant T7-LMP1 phage reconstitutes the antigenic and immunogenic properties of LMP1 and can serve as a vaccine against EBV.

Comparison of Immunogenicity in Rhesus Macaques of Transmitted-Founder, HIV-1 Group M Consensus, and Trivalent Mosaic Envelope Vaccines Formulated as a DNA Prime, NYVAC, and Envelope Protein Boost

PubMed Central

Hulot, Sandrine L.; Korber, Bette; Giorgi, Elena E.; Vandergrift, Nathan; Saunders, Kevin O.; Balachandran, Harikrishnan; Mach, Linh V.; Lifton, Michelle A.; Pantaleo, Giuseppe; Tartaglia, Jim; Phogat, Sanjay; Jacobs, Bertram; Kibler, Karen; Perdiguero, Beatriz; Gomez, Carmen E.; Esteban, Mariano; Rosati, Margherita; Felber, Barbara K.; Pavlakis, George N.; Parks, Robert; Lloyd, Krissey; Sutherland, Laura; Scearce, Richard; Letvin, Norman L.; Seaman, Michael S.; Alam, S. Munir; Montefiori, David; Liao, Hua-Xin; Haynes, Barton F.

2015-01-01

ABSTRACT An effective human immunodeficiency virus type 1 (HIV-1) vaccine must induce protective antibody responses, as well as CD4+ and CD8+ T cell responses, that can be effective despite extraordinary diversity of HIV-1. The consensus and mosaic immunogens are complete but artificial proteins, computationally designed to elicit immune responses with improved cross-reactive breadth, to attempt to overcome the challenge of global HIV diversity. In this study, we have compared the immunogenicity of a transmitted-founder (T/F) B clade Env (B.1059), a global group M consensus Env (Con-S), and a global trivalent mosaic Env protein in rhesus macaques. These antigens were delivered using a DNA prime-recombinant NYVAC (rNYVAC) vector and Env protein boost vaccination strategy. While Con-S Env was a single sequence, mosaic immunogens were a set of three Envs optimized to include the most common forms of potential T cell epitopes. Both Con-S and mosaic sequences retained common amino acids encompassed by both antibody and T cell epitopes and were central to globally circulating strains. Mosaics and Con-S Envs expressed as full-length proteins bound well to a number of neutralizing antibodies with discontinuous epitopes. Also, both consensus and mosaic immunogens induced significantly higher gamma interferon (IFN-γ) enzyme-linked immunosorbent spot assay (ELISpot) responses than B.1059 immunogen. Immunization with these proteins, particularly Con-S, also induced significantly higher neutralizing antibodies to viruses than B.1059 Env, primarily to tier 1 viruses. Both Con-S and mosaics stimulated more potent CD8-T cell responses against heterologous Envs than did B.1059. Both antibody and cellular data from this study strengthen the concept of using in silico-designed centralized immunogens for global HIV-1 vaccine development strategies. IMPORTANCE There is an increasing appreciation for the importance of vaccine-induced anti-Env antibody responses for preventing HIV-1 acquisition. This nonhuman primate study demonstrates that in silico-designed global HIV-1 immunogens, designed for a human clinical trial, are capable of eliciting not only T lymphocyte responses but also potent anti-Env antibody responses. PMID:25855741

APC targeting enhances immunogenicity of a novel multistage Fc-fusion tuberculosis vaccine in mice.

PubMed

Soleimanpour, Saman; Farsiani, Hadi; Mosavat, Arman; Ghazvini, Kiarash; Eydgahi, Mohammad Reza Akbari; Sankian, Mojtaba; Sadeghian, Hamid; Meshkat, Zahra; Rezaee, Seyed Abdolrahim

2015-12-01

Numerous studies have demonstrated that targeting immunogens to FcγR on antigen-presenting cells (APCs) can selectively uptake and increase cellular immunity in vitro and in vivo. Therefore, the present study was conducted to evaluate immunogenicity of a novel multistage tuberculosis vaccine, a combination of an early and a dormant immunogenic protein, ESAT6 and HspX, fused to Fcγ2a fragment of mouse IgG2a to target all forms of tuberculosis. Codon-optimized genes consisting of ESAT6, a linker, and HspX fused either to mouse Fcγ2a (ESAT6:HspX:mFcγ2a) or 6× His-tag (ESAT6:HspX:His) were synthesized. The resulting proteins were then produced in Pichia pastoris. The fusion proteins were separately emulsified in dimethyldioctadecylammonium bromide(DDA)-trehalose-6,6-dibehenate(TDB) adjuvant, and their immunogenicity with and without bacille Calmette-Guérin (BCG) was assessed in C57BL/6 mice. Th1, Th2, Th17, and T-reg cytokine patterns were evaluated using the ELISA method. Both multistage vaccines induced very strong IL-12 and IFN-γ secretion from splenic cells; the Fc-tagged subunit vaccine induced a more effective Th1 immune response (IFN-γ, 910 pg/mL, and IL-12, 854 pg/mL) with a very low increase in IL-17 (∼0.1 pg/mL) and IL-4 (37 pg/mL) and a mild increase in TGF-β (543 pg/mL) compared to the BCG or ESAT6:HspX:His primed and boosted groups. The production of IFN-γ to ESAT6:HspX:Fcγ2a was very consistent and showed an increasing trend for IL-12 compared to the BCG or ESAT6:HspX:His primed and boosted groups. Fcγ2a used as a delivery vehicle supported the idea of selective uptake, inducing cross-presentation and forming a proper anti-tuberculosis response in context of Th1/Th2 and Th17/T-reg balances, which is important for protection and prevention of damage.

Antibody formation towards porcine tissue in patients implanted with crosslinked heart valves is directed to antigenic tissue proteins and αGal epitopes and is reduced in healthy vegetarian subjects.

PubMed

Böer, Ulrike; Buettner, Falk F R; Schridde, Ariane; Klingenberg, Melanie; Sarikouch, Samir; Haverich, Axel; Wilhelmi, Mathias

2017-03-01

Glutaraldehyde-fixed porcine heart valves (ga-pV) are one of the most frequently used substitutes for insufficient aortic and pulmonary heart valves which, however, degenerate after 10-15 years. Yet, xeno-immunogenicity of ga-pV in humans including identification of immunogens still needs to be investigated. We here determined the immunogenicity of ga-pV in patients with respect to antibody formation, identity of immunogens and potential options to reduce antibody levels. Levels of tissue-specific and anti-αGal antibodies were determined retrospectively in patients who received ga-pV for 51 months (n=4), 25 months (n=6) or 5 months (n=4) and compared to age-matched untreated subjects (n=10) or younger subjects with or without vegetarian diet (n=12/15). Immunogenic proteins were investigated by Western blot approaches. Tissue-specific antibodies in patients were elevated after 5 (1.73-fold) and 25 (1.46-fold, both P<.0001) months but not after 51 months, whereas anti-Gal antibodies were induced 4.75-fold and 3.66-fold after 5 and 25 months (both P<.0001) and still were significantly elevated after 51 months (2.85-fold, P<.05). Western blots of porcine valve extracts with and without enzymatic deglycosylation revealed strong specific staining at ≈65 and ≈140 kDa by patient sera in either group which were identified by 2D Western blots and mass spectrometry as serum albumin and collagen 6A1. Vegetarian diet reduced significantly (0.63-fold, P<.01) the level of pre-formed αGal but not of tissue-specific antibodies. Immune response in patients towards ga-pV is induced by the porcine proteins albumin and collagen 6A1 as well as αGal epitopes, which seemed to be more sustained. In contrast, in healthy young subjects pre-formed anti-Gal antibodies were reduced by a meat-free nutrition. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Protein carriers of conjugate vaccines

PubMed Central

Pichichero, Michael E

2013-01-01

The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

Replication Competent Molecular Clones of HIV-1 Expressing Renilla Luciferase Facilitate the Analysis of Antibody Inhibition in PBMC

PubMed Central

Edmonds, Tara G.; Ding, Haitao; Yuan, Xing; Wei, Qing; Smith, Kendra S.; Conway, Joan A.; Wieczorek, Lindsay; Brown, Bruce; Polonis, Victoria; West, John T.; Montefiori, David C.; Kappes, John C.; Ochsenbauer, Christina

2010-01-01

Effective vaccine development for human immunodeficiency virus type 1 (HIV-1) will require assays that ascertain the capacity of vaccine immunogens to elicit neutralizing antibodies (NAb) to diverse HIV-1 strains. To facilitate NAb assessment in peripheral blood mononuclear cell (PBMC)-based assays, we developed an assay-adaptable platform based on a Renilla luciferase (LucR) expressing HIV-1 proviral backbone. LucR was inserted into pNL4-3 DNA, preserving all viral open reading frames. The proviral genome was engineered to facilitate expression of diverse HIV-1 env sequences, allowing analysis in an isogenic background. The resulting Env-IMC-LucR viruses are infectious, and LucR is stably expressed over multiple replications in PBMC. HIV-1 neutralization, targeting TZM-bl cells, was highly correlative comparing virus (LucR) and cell (firefly luciferase) readouts. In PBMC, NAb activity can be analyzed either within a single or multiple cycles of replication. These results represent advancement toward a standardizable PBMC-based neutralization assay for assessing HIV-1 vaccine immunogen efficacy. PMID:20863545

Replication competent molecular clones of HIV-1 expressing Renilla luciferase facilitate the analysis of antibody inhibition in PBMC.

PubMed

Edmonds, Tara G; Ding, Haitao; Yuan, Xing; Wei, Qing; Smith, Kendra S; Conway, Joan A; Wieczorek, Lindsay; Brown, Bruce; Polonis, Victoria; West, John T; Montefiori, David C; Kappes, John C; Ochsenbauer, Christina

2010-12-05

Effective vaccine development for human immunodeficiency virus type 1 (HIV-1) will require assays that ascertain the capacity of vaccine immunogens to elicit neutralizing antibodies (NAb) to diverse HIV-1 strains. To facilitate NAb assessment in peripheral blood mononuclear cell (PBMC)-based assays, we developed an assay-adaptable platform based on a Renilla luciferase (LucR) expressing HIV-1 proviral backbone. LucR was inserted into pNL4-3 DNA, preserving all viral open reading frames. The proviral genome was engineered to facilitate expression of diverse HIV-1 env sequences, allowing analysis in an isogenic background. The resulting Env-IMC-LucR viruses are infectious, and LucR is stably expressed over multiple replications in PBMC. HIV-1 neutralization, targeting TZM-bl cells, was highly correlative comparing virus (LucR) and cell (firefly luciferase) readouts. In PBMC, NAb activity can be analyzed either within a single or multiple cycles of replication. These results represent advancement toward a standardizable PBMC-based neutralization assay for assessing HIV-1 vaccine immunogen efficacy. Copyright © 2010 Elsevier Inc. All rights reserved.

Immunogenicity and protective efficacy of rotavirus VP8* fused to cholera toxin B subunit in a mouse model.

PubMed

Xue, Miaoge; Yu, Linqi; Jia, Lianzhi; Li, Yijian; Zeng, Yuanjun; Li, Tingdong; Ge, Shengxiang; Xia, Ningshao

2016-11-01

In attempts to develop recombinant subunit vaccines against rotavirus disease, it was previously shown that the N-terminal truncated VP8* protein, VP8-1 (aa26-231), is a good vaccine candidate when used for immunization in combination with Freund's adjuvant. However, this protein stimulated only weak immune response when aluminum hydroxide was used as an adjuvant. In this study, the nontoxic B subunit of cholera toxin (CTB) was employed as intra-molecular adjuvant to improve the immunogenicity of VP8-1. Both, the N-terminal and C-terminal fusion proteins, were purified to homogeneity, at which stage they formed pentamers, and showed significantly higher immunogenicity and protective efficacy than a VP8-1/aluminum hydroxide mixture in a mouse model. Compared to VP8-1-CTB, CTB-VP8-1 showed higher binding activity to both, GM1 and the conformation sensitive neutralizing monoclonal antibodies specific to VP8. More importantly, CTB-VP8-1 elicited higher titers of neutralizing antibodies and conferred higher protective efficacy than VP8-1-CTB. Therefore, the protein CTB-VP8-1, with enhanced immunogenicity and immunoprotectivity, could be considered as a viable candidate for further development of an alternative, replication-incompetent, parenterally administered vaccine against rotavirus disease.

Protein instability and immunogenicity: roadblocks to clinical application of injectable protein delivery systems for sustained release.

PubMed

Jiskoot, Wim; Randolph, Theodore W; Volkin, David B; Middaugh, C Russell; Schöneich, Christian; Winter, Gerhard; Friess, Wolfgang; Crommelin, Daan J A; Carpenter, John F

2012-03-01

Protein instability and immunogenicity are two main roadblocks to the clinical success of novel protein drug delivery systems. In this commentary, we discuss the need for more extensive analytical characterization in relation to concerns about protein instability in injectable drug delivery systems for sustained release. We then will briefly address immunogenicity concerns and outline current best practices for using state-of-the-art analytical assays to monitor protein stability for both conventional and novel therapeutic protein dosage forms. Next, we provide a summary of the stresses on proteins arising during preparation of drug delivery systems and subsequent in vivo release. We note the challenges and difficulties in achieving the absolute requirement of quantitatively assessing the degradation of protein molecules in a drug delivery system. We describe the potential roles for academic research in further improving protein stability and developing new analytical technologies to detect protein degradation byproducts in novel drug delivery systems. Finally, we provide recommendations for the appropriate approaches to formulation design and assay development to ensure that stable, minimally immunogenic formulations of therapeutic proteins are created. These approaches should help to increase the probability that novel drug delivery systems for sustained protein release will become more readily available as effective therapeutic agents to treat and benefit patients. Copyright © 2011 Wiley Periodicals, Inc.

Formulation and Immunogenicity studies of Type III Secretion System needle antigens as Vaccine Candidates

PubMed Central

Barrett, Brooke S.; Markham, Aaron P.; Esfandiary, Reza; Picking, Wendy L.; Picking, William D.; Joshi, Sangeeta B.; Middaugh, C. Russell

2013-01-01

Bacterial infections caused by Shigella flexneri, Salmonella typhimurium and Burkholderia pseudomallei are currently difficult to prevent due to the lack of a licensed vaccine. Here we present formulation and immunogenicity studies for the three type III secretion system (TTSS) needle proteins MxiHΔ5, PrgIΔ5 and BsaLΔ5 (each truncated by five residues at its C terminus) as potential candidates for vaccine development. These antigens are found to be thermally stabilized by the presence of carbohydrates and polyols. Additionally, all adsorb readily to aluminum hydroxide apparently through a combination of hydrogen bonds and/or Van der Waals forces. The interaction of these proteins with the aluminum-based adjuvant changes with time to resulting in varying degrees of irreversible binding. Peptide maps of desorbed protein, however, suggest that chemical changes are not responsible for this irreversible association. The ability of MxiHΔ5 and PrgIΔ5 to elicit strong humoral immune responses was tested in a murine model. When administered intramuscularly as monomers, the needle components exhibited dose dependent immunogenic behavior. The polymerized version of MxiH was exceptionally immunogenic even at low doses. The responses of both monomeric and polymerized forms were boosted by adsorption to an aluminum salt adjuvant. PMID:20845448

TLR-adjuvanted nanoparticle vaccines differentially influence the quality and longevity of responses to malaria antigen Pfs25.

PubMed

Thompson, Elizabeth A; Ols, Sebastian; Miura, Kazutoyo; Rausch, Kelly; Narum, David L; Spångberg, Mats; Juraska, Michal; Wille-Reece, Ulrike; Weiner, Amy; Howard, Randall F; Long, Carole A; Duffy, Patrick E; Johnston, Lloyd; O'Neil, Conlin P; Loré, Karin

2018-05-17

Transmission-blocking vaccines (TBVs) are considered an integral element of malaria eradication efforts. Despite promising evaluations of Plasmodium falciparum Pfs25-based TBVs in mice, clinical trials have failed to induce robust and long-lived Ab titers, in part due to the poorly immunogenic nature of Pfs25. Using nonhuman primates, we demonstrate that multiple aspects of Pfs25 immunity were enhanced by antigen encapsulation in poly(lactic-co-glycolic acid)-based [(PLGA)-based] synthetic vaccine particles (SVP[Pfs25]) and potent TLR-based adjuvants. SVP[Pfs25] increased Ab titers, Pfs25-specific plasmablasts, circulating memory B cells, and plasma cells in the bone marrow when benchmarked against the clinically tested multimeric form Pfs25-EPA given with GLA-LSQ. SVP[Pfs25] also induced the first reported Pfs25-specific circulating Th1 and Tfh cells to our knowledge. Multivariate correlative analysis indicated several mechanisms for the improved Ab responses. While Pfs25-specific B cells were responsible for increasing Ab titers, T cell responses stimulated increased Ab avidity. The innate immune activation differentially stimulated by the adjuvants revealed a strong correlation between type I IFN polarization, induced by R848 and CpG, and increased Ab half-life and longevity. Collectively, the data identify ways to improve vaccine-induced immunity to poorly immunogenic proteins, both by the choice of antigen and adjuvant formulation, and highlight underlying immunological mechanisms.

Alteration in the immunochemical dominance of determinants following the chemical modification of ox insulins: implications for the structure of the ox insulin monomer in solution.

PubMed Central

Hollins, P J; Nathan, M M

1979-01-01

Insulins of differing species, together with chemically modified insulins, were used in cross-reactivity experiments employing selected antisera raised to ox insulin in the Harley guinea-pig. The immunogen had been administered as a water-in-oil emulsion, using H. pertussis vaccine as adjuvant. Antibody was generated by determinants in the C-terminus of the B chain plus the adjacent N-terminus of the A chain, in the central core of the A chain (A8-A14 region) and in its anti-parallel N-terminus of the B chain. From this antibody pool chemically modified ox insulin selected antibody to unaltered determinants. The immunochemical data were compatible with monomeric ox insulin being immunogenic, the immunogen perhaps being recognized by the immune system in the form of the Molecule-II rather than the Molecule-I of the dimer pair (as originally suggested by X-ray crystallographic data). PMID:93526

Modelling the immunological response to a tetravalent dengue vaccine from multiple phase-2 trials in Latin America and South East Asia.

PubMed

Dorigatti, Ilaria; Aguas, Ricardo; Donnelly, Christl A; Guy, Bruno; Coudeville, Laurent; Jackson, Nicholas; Saville, Melanie; Ferguson, Neil M

2015-07-17

The most advanced dengue vaccine candidate is a live-attenuated recombinant vaccine containing the four dengue viruses on the yellow fever vaccine backbone (CYD-TDV) developed by Sanofi Pasteur. Several analyses have been published on the safety and immunogenicity of the CYD-TDV vaccine from single trials but none modelled the heterogeneity observed in the antibody responses elicited by the vaccine. We analyse the immunogenicity data collected in five phase-2 trials of the CYD-TDV vaccine. We provide a descriptive analysis of the aggregated datasets and fit the observed post-vaccination PRNT50 titres against the four dengue (DENV) serotypes using multivariate regression models. We find that the responses to CYD-TDV are principally predicted by the baseline immunological status against DENV, but the trial is also a significant predictor. We find that the CYD-TDV vaccine generates similar titres against all serotypes following the third dose, though DENV4 is immunodominant after the first dose. This study contributes to a better understanding of the immunological responses elicited by CYD-TDV. The recent availability of phase-3 data is a unique opportunity to further investigate the immunogenicity and efficacy of the CYD-TDV vaccine, especially in subjects with different levels of pre-existing immunity against DENV. Modelling multiple immunological outcomes with a single multivariate model offers advantages over traditional approaches, capturing correlations between response variables, and the statistical method adopted in this study can be applied to a variety of infections with interacting strains. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Generation of a More Immunogenic Measles Vaccine by Increasing Its Hemagglutinin Expression

PubMed Central

Julik, Emily

2016-01-01

ABSTRACT Imported measles virus (MV) outbreaks are maintained by poor vaccine responders and unvaccinated people. A convenient but more immunogenic vaccination strategy would enhance vaccine performance, contributing to measles eradication efforts. We report here the generation of alternative pediatric vaccines against MV with increased expression of the H protein in the background of the current MV vaccine strain. We generated two recombinants: MVvac2-H2, with increased full-length H expression resulting in a 3-fold increase in H incorporation into virions, and MVvac2-Hsol, vectoring a truncated, soluble form of the H protein that is secreted into the supernatants of infected cells. Replication fitness was conserved despite the duplication of the H cistron for both vectors. The modification to the envelope of MVvac2-H2 conferred upon this virus a measurable level of resistance to in vitro neutralization by MV polyclonal immune sera without altering its thermostability. Most interestingly, both recombinant MVs with enhanced H expression were significantly more immunogenic than their parental strain in outbred mice, while MVvac2-H2 additionally proved more immunogenic after a single, human-range dose in genetically modified MV-susceptible mice. IMPORTANCE Measles incidence was reduced drastically following the introduction of attenuated vaccines, but progress toward the eradication of this virus has stalled, and MV still threatens unvaccinated populations. Due to the contributions of primary vaccine failures and too-young-to-be-vaccinated infants to this problem, more immunogenic measles vaccines are highly desirable. We generated two experimental MV vaccines based on a current vaccine's genome but with enriched production of the H protein, the main MV antigen in provoking immunity. One vaccine incorporated H at higher rates in the viral envelope, and the other secreted a soluble H protein from infected cells. The increased expression of H by these vectors improved neutralizing responses induced in two small-animal models of MV immunogenicity. The enhanced immunogenicity of these vectors, mainly from the MV that incorporates additional H, suggests their value as potential alternative pediatric MV vaccines. PMID:26984727

Preferential Targeting of Conserved Gag Regions after Vaccination with a Heterologous DNA Prime-Modified Vaccinia Virus Ankara Boost HIV-1 Vaccine Regimen.

PubMed

Bauer, Asli; Podola, Lilli; Mann, Philipp; Missanga, Marco; Haule, Antelmo; Sudi, Lwitiho; Nilsson, Charlotta; Kaluwa, Bahati; Lueer, Cornelia; Mwakatima, Maria; Munseri, Patricia J; Maboko, Leonard; Robb, Merlin L; Tovanabutra, Sodsai; Kijak, Gustavo; Marovich, Mary; McCormack, Sheena; Joseph, Sarah; Lyamuya, Eligius; Wahren, Britta; Sandström, Eric; Biberfeld, Gunnel; Hoelscher, Michael; Bakari, Muhammad; Kroidl, Arne; Geldmacher, Christof

2017-09-15

Prime-boost vaccination strategies against HIV-1 often include multiple variants for a given immunogen for better coverage of the extensive viral diversity. To study the immunologic effects of this approach, we characterized breadth, phenotype, function, and specificity of Gag-specific T cells induced by a DNA-prime modified vaccinia virus Ankara (MVA)-boost vaccination strategy, which uses mismatched Gag immunogens in the TamoVac 01 phase IIa trial. Healthy Tanzanian volunteers received three injections of the DNA-SMI vaccine encoding a subtype B and AB-recombinant Gag p37 and two vaccinations with MVA-CMDR encoding subtype A Gag p55 Gag-specific T-cell responses were studied in 42 vaccinees using fresh peripheral blood mononuclear cells. After the first MVA-CMDR boost, vaccine-induced gamma interferon-positive (IFN-γ + ) Gag-specific T-cell responses were dominated by CD4 + T cells ( P < 0.001 compared to CD8 + T cells) that coexpressed interleukin-2 (IL-2) (66.4%) and/or tumor necrosis factor alpha (TNF-α) (63.7%). A median of 3 antigenic regions were targeted with a higher-magnitude median response to Gag p24 regions, more conserved between prime and boost, compared to those of regions within Gag p15 (not primed) and Gag p17 (less conserved; P < 0.0001 for both). Four regions within Gag p24 each were targeted by 45% to 74% of vaccinees upon restimulation with DNA-SMI-Gag matched peptides. The response rate to individual antigenic regions correlated with the sequence homology between the MVA- and DNA Gag-encoded immunogens ( P = 0.04, r 2 = 0.47). In summary, after the first MVA-CMDR boost, the sequence-mismatched DNA-prime MVA-boost vaccine strategy induced a Gag-specific T-cell response that was dominated by polyfunctional CD4 + T cells and that targeted multiple antigenic regions within the conserved Gag p24 protein. IMPORTANCE Genetic diversity is a major challenge for the design of vaccines against variable viruses. While including multiple variants for a given immunogen in prime-boost vaccination strategies is one approach that aims to improve coverage for global virus variants, the immunologic consequences of this strategy have been poorly defined so far. It is unclear whether inclusion of multiple variants in prime-boost vaccination strategies improves recognition of variant viruses by T cells and by which mechanisms this would be achieved, either by improved cross-recognition of multiple variants for a given antigenic region or through preferential targeting of antigenic regions more conserved between prime and boost. Engineering vaccines to induce adaptive immune responses that preferentially target conserved antigenic regions of viral vulnerability might facilitate better immune control after preventive and therapeutic vaccination for HIV and for other variable viruses. Copyright © 2017 American Society for Microbiology.

Different levels of immunogenicity of two strains of Fowlpox virus as recombinant vaccine vectors eliciting T-cell responses in heterologous prime-boost vaccination strategies.

PubMed

Cottingham, Matthew G; van Maurik, Andre; Zago, Manola; Newton, Angela T; Anderson, Richard J; Howard, M Keith; Schneider, Jörg; Skinner, Michael A

2006-07-01

The FP9 strain of F has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxvirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified V Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These "passage-specific" alterations are hypothesized to be involved in determining the immunogenicity of fowlpox virus as a recombinant vaccine vector.

Safety and immunogenicity of candidate vaccine M72/AS01E in adolescents in a TB endemic setting.

PubMed

Penn-Nicholson, Adam; Geldenhuys, Hennie; Burny, Wivine; van der Most, Robbert; Day, Cheryl L; Jongert, Erik; Moris, Philippe; Hatherill, Mark; Ofori-Anyinam, Opokua; Hanekom, Willem; Bollaerts, Anne; Demoitie, Marie-Ange; Kany Luabeya, Angelique Kany; De Ruymaeker, Evi; Tameris, Michele; Lapierre, Didier; Scriba, Thomas J

2015-07-31

Vaccination that prevents tuberculosis (TB) disease, particularly in adolescents, would have the greatest impact on the global TB epidemic. Safety, reactogenicity and immunogenicity of the vaccine candidate M72/AS01E was evaluated in healthy, HIV-negative adolescents in a TB endemic region, regardless of Mycobacterium tuberculosis (M.tb) infection status. In a phase II, double-blind randomized, controlled study (NCT00950612), two doses of M72/AS01E or placebo were administered intramuscularly, one month apart. Participants were followed-up post-vaccination, for 6 months. M72-specific immunogenicity was evaluated by intracellular cytokine staining analysis of T cells and NK cells by flow cytometry. No serious adverse events were recorded. M72/AS01E induced robust T cell and antibody responses, including antigen-dependent NK cell IFN-γ production. CD4 and CD8 T cell responses were sustained at 6 months post vaccination. Irrespective of M.tb infection status, vaccination induced a high frequency of M72-specific CD4 T cells expressing multiple combinations of Th1 cytokines, and low level IL-17. We observed rapid boosting of immune responses in M.tb-infected participants, suggesting natural infection acts as a prime to vaccination. The clinically acceptable safety and immunogenicity profile of M72/AS01E in adolescents living in an area with high TB burden support the move to efficacy trials. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Safety and immunogenicity of candidate vaccine M72/AS01E in adolescents in a TB endemic setting

PubMed Central

Penn-Nicholson, Adam; Geldenhuys, Hennie; Burny, Wivine; van der Most, Robbert; Day, Cheryl L.; Jongert, Erik; Moris, Philippe; Hatherill, Mark; Ofori-Anyinam, Opokua; Hanekom, Willem

2018-01-01

Background Vaccination that prevents tuberculosis (TB) disease, particularly in adolescents, would have the greatest impact on the global TB epidemic. Safety, reactogenicity and immunogenicity of the vaccine candidate M72/AS01E was evaluated in healthy, HIV-negative adolescents in a TB endemic region, regardless of Mycobacterium tuberculosis (M.tb) infection status. Methods In a phase II, double-blind randomized, controlled study (NCT00950612), two doses of M72/AS01E or placebo were administered intramuscularly, one month apart. Participants were followed-up post-vaccination, for 6 months. M72-specific immunogenicity was evaluated by intracellular cytokine staining analysis of T cells and NK cells by flow cytometry. Results No serious adverse events were recorded. M72/AS01E induced robust T cell and antibody responses, including antigen-dependent NK cell IFN-γ production. CD4 and CD8 T cell responses were sustained at 6 months post vaccination. Irrespective of M.tb infection status, vaccination induced a high frequency of M72-specific CD4 T cells expressing multiple combinations of Th1 cytokines, and low level IL-17. We observed rapid boosting of immune responses in M.tb-infected participants, suggesting natural infection acts as a prime to vaccination. Conclusions The clinically acceptable safety and immunogenicity profile of M72/AS01E in adolescents living in an area with high TB burden support the move to efficacy trials. PMID:26072017

Pre-existing immunity against vaccine vectors – friend or foe?

PubMed Central

Saxena, Manvendra; Van, Thi Thu Hao; Baird, Fiona J.; Coloe, Peter J.

2013-01-01

Over the last century, the successful attenuation of multiple bacterial and viral pathogens has led to an effective, robust and safe form of vaccination. Recently, these vaccines have been evaluated as delivery vectors for heterologous antigens, as a means of simultaneous vaccination against two pathogens. The general consensus from published studies is that these vaccine vectors have the potential to be both safe and efficacious. However, some of the commonly employed vectors, for example Salmonella and adenovirus, often have pre-existing immune responses in the host and this has the potential to modify the subsequent immune response to a vectored antigen. This review examines the literature on this topic, and concludes that for bacterial vectors there can in fact, in some cases, be an enhancement in immunogenicity, typically humoral, while for viral vectors pre-existing immunity is a hindrance for subsequent induction of cell-mediated responses. PMID:23175507

Antigenicity and Immunogenicity of RV144 Vaccine AIDSVAX Clade E Envelope Immunogen Is Enhanced by a gp120 N-Terminal Deletion

PubMed Central

Liao, Hua-Xin; Tomaras, Georgia D.; Bonsignori, Mattia; Tsao, Chun-Yen; Hwang, Kwan-Ki; Chen, Haiyan; Lloyd, Krissey E.; Bowman, Cindy; Sutherland, Laura; Jeffries, Thomas L.; Kozink, Daniel M.; Stewart, Shelley; Anasti, Kara; Jaeger, Frederick H.; Parks, Robert; Yates, Nicole L.; Overman, R. Glenn; Sinangil, Faruk; Berman, Phillip W.; Pitisuttithum, Punnee; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Karasavva, Nicos; Rerks-Ngarm, Supachai; Kim, Jerome H.; Michael, Nelson L.; Zolla-Pazner, Susan; Santra, Sampa; Letvin, Norman L.; Harrison, Stephen C.

2013-01-01

An immune correlates analysis of the RV144 HIV-1 vaccine trial revealed that antibody responses to the gp120 V1/V2 region correlated inversely with infection risk. The RV144 protein immunogens (A244-rp120 and MN-rgp120) were modified by an N-terminal 11-amino-acid deletion (Δ11) and addition of a herpes simplex virus (HSV) gD protein-derived tag (gD). We investigated the effects of these modifications on gp120 expression, antigenicity, and immunogenicity by comparing unmodified A244 gp120 with both Δ11 deletion and gD tag and with Δ11 only. Analysis of A244 gp120, with or without Δ11 or gD, demonstrated that the Δ11 deletion, without the addition of gD, was sufficient for enhanced antigenicity to gp120 C1 region, conformational V2, and V1/V2 gp120 conformational epitopes. RV144 vaccinee serum IgGs bound more avidly to A244 gp120 Δ11 than to the unmodified gp120, and their binding was blocked by C1, V2, and V1/V2 antibodies. Rhesus macaques immunized with the three different forms of A244 gp120 proteins gave similar levels of gp120 antibody titers, although higher antibody titers developed earlier in A244 Δ11 gp120-immunized animals. Conformational V1/V2 monoclonal antibodies (MAbs) gave significantly higher levels of blocking of plasma IgG from A244 Δ11 gp120-immunized animals than IgG from animals immunized with unmodified A244 gp120, thus indicating a qualitative difference in the V1/V2 antibodies induced by A244 Δ11 gp120. These results demonstrate that deletion of N-terminal residues in the RV144 A244 gp120 immunogen improves both envelope antigenicity and immunogenicity. PMID:23175357

Atheroprotective immunization with malondialdehyde-modified LDL is hapten specific and dependent on advanced MDA adducts: implications for development of an atheroprotective vaccine1[S

PubMed Central

Gonen, Ayelet; Hansen, Lotte F.; Turner, William W.; Montano, Erica N.; Que, Xuchu; Rafia, Apaїs; Chou, Meng-Yun; Wiesner, Philipp; Tsiantoulas, Dimitrios; Corr, Maripat; VanNieuwenhze, Michael S.; Tsimikas, Sotirios; Binder, Christoph J.; Witztum, Joseph L.; Hartvigsen, Karsten

2014-01-01

Immunization with homologous malondialdehyde (MDA)-modified LDL (MDA-LDL) leads to atheroprotection in experimental models supporting the concept that a vaccine to oxidation-specific epitopes (OSEs) of oxidized LDL could limit atherogenesis. However, modification of human LDL with OSE to use as an immunogen would be impractical for generalized use. Furthermore, when MDA is used to modify LDL, a wide variety of related MDA adducts are formed, both simple and more complex. To define the relevant epitopes that would reproduce the atheroprotective effects of immunization with MDA-LDL, we sought to determine the responsible immunodominant and atheroprotective adducts. We now demonstrate that fluorescent adducts of MDA involving the condensation of two or more MDA molecules with lysine to form malondialdehyde-acetaldehyde (MAA)-type adducts generate immunodominant epitopes that lead to atheroprotective responses. We further demonstrate that a T helper (Th) 2-biased hapten-specific humoral and cellular response is sufficient, and thus, MAA-modified homologous albumin is an equally effective immunogen. We further show that such Th2-biased humoral responses per se are not atheroprotective if they do not target relevant antigens. These data demonstrate the feasibility of development of a small-molecule immunogen that could stimulate MAA-specific immune responses, which could be used to develop a vaccine approach to retard or prevent atherogenesis. PMID:25143462

Engineering RENTA, a DNA prime-MVA boost HIV vaccine tailored for Eastern and Central Africa.

PubMed

Nkolola, J P; Wee, E G-T; Im, E-J; Jewell, C P; Chen, N; Xu, X-N; McMichael, A J; Hanke, T

2004-07-01

For the development of human immunodeficiency virus type 1 (HIV-1) vaccines, traditional approaches inducing virus-neutralizing antibodies have so far failed. Thus the effort is now focused on elicitation of cellular immunity. We are currently testing in clinical trials in the United Kingdom and East Africa a T-cell vaccine consisting of HIV-1 clade A Gag-derived immunogen HIVA delivered in a prime-boost regimen by a DNA plasmid and modified vaccinia virus Ankara (MVA). Here, we describe engineering and preclinical development of a second immunogen RENTA, which will be used in combination with the present vaccine in a four-component DNA/HIVA-RENTA prime-MVA/HIVA-RENTA boost formulation. RENTA is a fusion protein derived from consensus HIV clade A sequences of Tat, reverse transcriptase, Nef and gp41. We inactivated the natural biological activities of the HIV components and confirmed immunogenicities of the pTHr.RENTA and MVA.RENTA vaccines in mice. Furthermore, we demonstrated in mice and rhesus monkeys broadening of HIVA-elicited T-cell responses by a parallel induction of HIVA- and RENTA-specific responses recognizing multiple HIV epitopes.

Zwitterionic Nanocages Overcome the Efficacy Loss of Biologic Drugs.

PubMed

Li, Bowen; Yuan, Zhefan; Zhang, Peng; Sinclair, Andrew; Jain, Priyesh; Wu, Kan; Tsao, Caroline; Xie, Jingyi; Hung, Hsiang-Chieh; Lin, Xiaojie; Bai, Tao; Jiang, Shaoyi

2018-04-01

For biotherapeutics that require multiple administrations to fully cure diseases, the induction of undesirable immune response is one common cause for the failure of their treatment. Covalent binding of hydrophilic polymers to proteins is commonly employed to mitigate potential immune responses. However, while this technique is proved to partially reduce the antibodies (Abs) reactive to proteins, it may induce Abs toward their associated polymers and thus result in the loss of efficacy. Zwitterionic poly(carboxybetaine) (PCB) is recently shown to improve the immunologic properties of proteins without inducing any antipolymer Abs against itself. However, it is unclear if the improved immunologic profiles can translate to better clinical outcomes since improved immunogenicity cannot directly reflect amelioration in efficacy. Here, a PCB nanocage (PCB NC) is developed, which can physically encase proteins while keeping their structure intact. PCB NC encapsulation of uricase, a highly immunogenic enzyme, is demonstrated to eradicate all the immune responses. To bridge the gap between immunogenicity and efficacy studies, the therapeutic performance of PCB NC uricase is evaluated and compared with its PEGylated counterpart in a clinical-mimicking gouty rat model to determine any loss of efficacy evoked after five administrations. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Progress in Developing Virus-like Particle Influenza Vaccines

PubMed Central

Quan, Fu-Shi; Lee, Young-Tae; Kim, Ki-Hye; Kim, Min-Chul; Kang, Sang-Moo

2016-01-01

Summary Recombinant vaccines based on virus-like particles (VLPs) or nanoparticles have been successful in their safety and efficacy in preclinical and clinical studies. The technology of expressing enveloped VLP vaccines has combined with molecular engineering of proteins in membrane-anchor and immunogenic forms mimicking the native conformation of surface proteins on the enveloped viruses. This review summarizes recent developments in influenza VLP vaccines against seasonal, pandemic, and avian influenza viruses from the perspective of use in humans. The immunogenicity and efficacies of influenza VLP vaccine in the homologous and cross-protection were reviewed. Discussions include limitations of current influenza vaccination strategies and future directions to confer broadly cross protective new influenza vaccines as well as vaccination. PMID:27058302

Trial watch: Immunogenic cell death induction by anticancer chemotherapeutics.

PubMed

Garg, Abhishek D; More, Sanket; Rufo, Nicole; Mece, Odeta; Sassano, Maria Livia; Agostinis, Patrizia; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2017-01-01

The expression "immunogenic cell death" (ICD) refers to a functionally unique form of cell death that facilitates (instead of suppressing) a T cell-dependent immune response specific for dead cell-derived antigens. ICD critically relies on the activation of adaptive responses in dying cells, culminating with the exposure or secretion of immunostimulatory molecules commonly referred to as "damage-associated molecular patterns". Only a few agents can elicit bona fide ICD, including some clinically established chemotherapeutics such as doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin. In this Trial Watch, we discuss recent progress on the development of ICD-inducing chemotherapeutic regimens, focusing on studies that evaluate clinical efficacy in conjunction with immunological biomarkers.

Virus-like particles as universal influenza vaccines

PubMed Central

Kang, Sang-Moo; Kim, Min-Chul; Compans, Richard W

2012-01-01

Current influenza vaccines are primarily targeted to induce immunity to the influenza virus strain-specific hemagglutinin antigen and are not effective in controlling outbreaks of new pandemic viruses. An approach for developing universal vaccines is to present highly conserved antigenic epitopes in an immunogenic conformation such as virus-like particles (VLPs) together with an adjuvant to enhance the vaccine immunogenicity. In this review, the authors focus on conserved antigenic targets and molecular adjuvants that were presented in VLPs. Conserved antigenic targets that include the hemagglutinin stalk domain, the external domain of influenza M2 and neuraminidase are discussed in addition to molecular adjuvants that are engineered to be incorporated into VLPs in a membrane-anchored form. PMID:23002980

An Enhanced Synthetic Multiclade DNA Prime Induces Improved Cross-Clade-Reactive Functional Antibodies when Combined with an Adjuvanted Protein Boost in Nonhuman Primates

PubMed Central

Wise, Megan C.; Hutnick, Natalie A.; Pollara, Justin; Myles, Devin J. F.; Williams, Constance; Yan, Jian; LaBranche, Celia C.; Khan, Amir S.; Sardesai, Niranjan Y.; Montefiori, David; Barnett, Susan W.; Zolla-Pazner, Susan; Ferrari, Guido

2015-01-01

ABSTRACT The search for an efficacious human immunodeficiency virus type 1 (HIV-1) vaccine remains a pressing need. The moderate success of the RV144 Thai clinical vaccine trial suggested that vaccine-induced HIV-1-specific antibodies can reduce the risk of HIV-1 infection. We have made several improvements to the DNA platform and have previously shown that improved DNA vaccines alone are capable of inducing both binding and neutralizing antibodies in small-animal models. In this study, we explored how an improved DNA prime and recombinant protein boost would impact HIV-specific vaccine immunogenicity in rhesus macaques (RhM). After DNA immunization with either a single HIV Env consensus sequence or multiple constructs expressing HIV subtype-specific Env consensus sequences, we detected both CD4+ and CD8+ T-cell responses to all vaccine immunogens. These T-cell responses were further increased after protein boosting to levels exceeding those of DNA-only or protein-only immunization. In addition, we observed antibodies that exhibited robust cross-clade binding and neutralizing and antibody-dependent cellular cytotoxicity (ADCC) activity after immunization with the DNA prime-protein boost regimen, with the multiple-Env formulation inducing a more robust and broader response than the single-Env formulation. The magnitude and functionality of these responses emphasize the strong priming effect improved DNA immunogens can induce, which are further expanded upon protein boost. These results support further study of an improved synthetic DNA prime together with a protein boost for enhancing anti-HIV immune responses. IMPORTANCE Even with effective antiretroviral drugs, HIV remains an enormous global health burden. Vaccine development has been problematic in part due to the high degree of diversity and poor immunogenicity of the HIV Env protein. Studies suggest that a relevant HIV vaccine will likely need to induce broad cellular and humoral responses from a simple vaccine regimen due to the resource-limited setting in which the HIV pandemic is most rampant. DNA vaccination lends itself well to increasing the amount of diversity included in a vaccine due to the ease of manufacturing multiple plasmids and formulating them as a single immunization. By increasing the number of Envs within a formulation, we were able to show an increased breadth of responses as well as improved functionality induced in a nonhuman primate model. This increased breadth could be built upon, leading to better coverage against circulating strains with broader vaccine-induced protection. PMID:26085155

Consensus guidelines for the detection of immunogenic cell death

PubMed Central

Kepp, Oliver; Senovilla, Laura; Vitale, Ilio; Vacchelli, Erika; Adjemian, Sandy; Agostinis, Patrizia; Apetoh, Lionel; Aranda, Fernando; Barnaba, Vincenzo; Bloy, Norma; Bracci, Laura; Breckpot, Karine; Brough, David; Buqué, Aitziber; Castro, Maria G.; Cirone, Mara; Colombo, Maria I.; Cremer, Isabelle; Demaria, Sandra; Dini, Luciana; Eliopoulos, Aristides G.; Faggioni, Alberto; Formenti, Silvia C.; Fučíková, Jitka; Gabriele, Lucia; Gaipl, Udo S.; Galon, Jérôme; Garg, Abhishek; Ghiringhelli, François; Giese, Nathalia A.; Guo, Zong Sheng; Hemminki, Akseli; Herrmann, Martin; Hodge, James W.; Holdenrieder, Stefan; Honeychurch, Jamie; Hu, Hong-Min; Huang, Xing; Illidge, Tim M.; Kono, Koji; Korbelik, Mladen; Krysko, Dmitri V.; Loi, Sherene; Lowenstein, Pedro R.; Lugli, Enrico; Ma, Yuting; Madeo, Frank; Manfredi, Angelo A.; Martins, Isabelle; Mavilio, Domenico; Menger, Laurie; Merendino, Nicolò; Michaud, Michael; Mignot, Gregoire; Mossman, Karen L.; Multhoff, Gabriele; Oehler, Rudolf; Palombo, Fabio; Panaretakis, Theocharis; Pol, Jonathan; Proietti, Enrico; Ricci, Jean-Ehrland; Riganti, Chiara; Rovere-Querini, Patrizia; Rubartelli, Anna; Sistigu, Antonella; Smyth, Mark J.; Sonnemann, Juergen; Spisek, Radek; Stagg, John; Sukkurwala, Abdul Qader; Tartour, Eric; Thorburn, Andrew; Thorne, Stephen H.; Vandenabeele, Peter; Velotti, Francesca; Workenhe, Samuel T.; Yang, Haining; Zong, Wei-Xing; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2014-01-01

Apoptotic cells have long been considered as intrinsically tolerogenic or unable to elicit immune responses specific for dead cell-associated antigens. However, multiple stimuli can trigger a functionally peculiar type of apoptotic demise that does not go unnoticed by the adaptive arm of the immune system, which we named “immunogenic cell death” (ICD). ICD is preceded or accompanied by the emission of a series of immunostimulatory damage-associated molecular patterns (DAMPs) in a precise spatiotemporal configuration. Several anticancer agents that have been successfully employed in the clinic for decades, including various chemotherapeutics and radiotherapy, can elicit ICD. Moreover, defects in the components that underlie the capacity of the immune system to perceive cell death as immunogenic negatively influence disease outcome among cancer patients treated with ICD inducers. Thus, ICD has profound clinical and therapeutic implications. Unfortunately, the gold-standard approach to detect ICD relies on vaccination experiments involving immunocompetent murine models and syngeneic cancer cells, an approach that is incompatible with large screening campaigns. Here, we outline strategies conceived to detect surrogate markers of ICD in vitro and to screen large chemical libraries for putative ICD inducers, based on a high-content, high-throughput platform that we recently developed. Such a platform allows for the detection of multiple DAMPs, like cell surface-exposed calreticulin, extracellular ATP and high mobility group box 1 (HMGB1), and/or the processes that underlie their emission, such as endoplasmic reticulum stress, autophagy and necrotic plasma membrane permeabilization. We surmise that this technology will facilitate the development of next-generation anticancer regimens, which kill malignant cells and simultaneously convert them into a cancer-specific therapeutic vaccine. PMID:25941621

Human regulatory T cells do not suppress the antitumor immunity in the bone marrow: a role for bone marrow stromal cells in neutralizing regulatory T cells.

PubMed

Guichelaar, Teun; Emmelot, Maarten E; Rozemuller, Henk; Martini, Bianka; Groen, Richard W J; Storm, Gert; Lokhorst, Henk M; Martens, Anton C; Mutis, Tuna

2013-03-15

Regulatory T cells (Tregs) are potent tools to prevent graft-versus-host disease (GVHD) induced after allogeneic stem cell transplantation or donor lymphocyte infusions. Toward clinical application of Tregs for GVHD treatment, we investigated the impact of Tregs on the therapeutic graft-versus-tumor (GVT) effect against human multiple myeloma tumors with various immunogenicities, progression rates, and localizations in a humanized murine model. Immunodeficient Rag2(-/-)γc(-/-) mice, bearing various human multiple myeloma tumors, were treated with human peripheral blood mononuclear cell (PBMC) alone or together with autologous ex vivo cultured Tregs. Mice were analyzed for the in vivo engraftment, homing of T-cell subsets, development of GVHD and GVT. In additional in vitro assays, Tregs that were cultured together with bone marrow stromal cells were analyzed for phenotype and functions. Treatment with PBMC alone induced variable degrees of antitumor response, depending on the immunogenicity and the growth rate of the tumor. Coinfusion of Tregs did not impair the antitumor response against tumors residing within the bone marrow, irrespective of their immunogenicity or growth rates. In contrast, Tregs readily inhibited the antitumor effect against tumors growing outside the bone marrow. Exploring this remarkable phenomenon, we discovered that bone marrow stroma neutralizes the suppressive activity of Tregs in part via production of interleukin (IL)-1β/IL-6. We furthermore found in vitro and in vivo evidence of conversion of Tregs into IL-17-producing T cells in the bone marrow environment. These results provide new insights into the Treg immunobiology and indicate the conditional benefits of future Treg-based therapies.

Influence of protein expression system on elicitation of IgE antibody responses: experience with lactoferrin.

PubMed

Almond, Rachael J; Flanagan, Brian F; Kimber, Ian; Dearman, Rebecca J

2012-11-15

With increased interest in genetically modified (GM) crop plants there is an important need to understand the properties that contribute to the ability of such novel proteins to provoke immune and/or allergic responses. One characteristic that may be relevant is glycosylation, particularly as novel expression systems (e.g. bacterial to plant) will impact on the protein glycoprofile. The allergenicity (IgE inducing) and immunogenicity (IgG inducing) properties of wild type native human lactoferrin (NLF) from human milk (hm) and neutrophil granules (n) and a recombinant molecule produced in rice (RLF) have been assessed. These forms of lactoferrin have identical amino acid sequences, but different glycosylation patterns: hmNLF and nNLF have complex glycoprofiles including Lewis (Le)(x) structures, with particularly high levels of Le(x) expressed by nNLF, whereas RLF is simpler and rich in mannose residues. Antibody responses induced in BALB/c strain mice by intraperitoneal exposure to the different forms of lactoferrin were characterised. Immunisation with both forms of NLF stimulated substantial IgG and IgE antibody responses. In contrast, the recombinant molecule was considerably less immunogenic and failed to stimulate detectable IgE, irrespective of endotoxin and iron content. The glycans did not contribute to epitope formation, with equivalent IgE and IgG binding recorded for high titre anti-NLF antisera regardless of whether the immunising NLF or the recombinant molecule were used substrates in the analyses. These data demonstrate that differential glycosylation profiles can have a profound impact on protein allergenicity and immunogenicity, with mannose and Le(x) exhibiting opposing effects. These results have clear relevance for characterising the allergenic hazards of novel proteins in GM crops. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

[Prokaryotic expression and immunogenicity analysis of the chimeric HBcAg containing APP beta cleavage site peptide and Aβ(1-15);].

PubMed

Feng, Gai-feng; Wang, Jun-yang; Jin, Hui; Wang, Wei-xi; Qian, Yi-hua; Yang, Wei-na; Wang, Quan-ying; Yang, Guang-xiao

2011-11-01

To construct the recombinant prokaryotic expression plasmid pET/c-ABCSP-Aβ(15-c);, and evaluate the immunogenicity of the fusion protein expressed in E.coli. The gene fragment HBc88-144 was amplified by PCR and subcloned to pUC19. The APP beta cleavage site peptide(ABCSP) and Aβ(1-15); gene(ABCSP-Aβ(15);) was amplified by PCR and inserted downstream of HBc1-71 in pGEMEX/c1-71. After restriction enzyme digestion, c1-17-ABCSP-Aβ(15); were connected with HBc88-144, yielding the recombinant gene c-ABCSP-Aβ(15-c);. c-ABCSP-Aβ(15-c); gene was subcloned into pET-28a(+).The fusion protein expressed in transformed E.coli BL21 was induced with IPTG and analyzed by SDS-PAGE. The virus-like particles (VLP) formed by fusion protein was observed with Transmission Electron Microscope (TEM). 4 Kunming (KM) mice received intraperitoneal injection (i.p) of fusion protein VLP. The antibody was detected by indirect ELISA. The recombinant gene was confirmed by restriction enzyme digestion and DNA sequencing. After IPTG induction, fusion protein was expressed and mainly existed in the sediment of the bacterial lysate. The expression level was 40% of all the proteins in the sediment. The fusion protein could form VLP. After 5 times of immunization, the titer of anti-ABCSP and anti-Aβantibody in sera of KM mice reached up to 1:5 000 and 1:10 000 respectively, while the anti-HBc antibody was undetectable. Recombinant c-ABCSP-Aβ(15-c); gene can be expressed in E.coli. The expressed protein could form VLP and has a strong immunogenicity. This study lays the foundation for the study of AD genetic engineering vaccine.

Virus-like particle expression and assembly in plants: hepatitis B and Norwalk viruses.

PubMed

Huang, Zhong; Elkin, Galina; Maloney, Bryan J; Beuhner, Norene; Arntzen, Charles J; Thanavala, Yasmin; Mason, Hugh S

2005-03-07

Expression of vaccine antigens in plants and delivery via ingestion of transgenic plant material has shown promise in numerous pre-clinical animal studies and in a few clinical trials. A number of different viral antigens have been tested, and among the most promising are those that can assemble virus-like particles (VLP), which mimic the form of authentic virions and display neutralizing antibody epitopes. We have extensively studied plant expression, VLP assembly, and immunogenicity of hepatitis B surface antigen (HBsAg) and Norwalk virus capsid protein (NVCP). The HBsAg small protein (S protein) was found by TEM to assemble tubular membrane complexes derived from endoplasmic reticulum in suspension cultured cells of tobacco and soybean, and in potato leaf and tuber tissues. The potato material was immunogenic in mice upon delivery by ingestion. Here we describe the plant expression and immunogenicity of HBsAg middle protein (M protein or pre-S2 + S) which contains additional 55 amino acid pre-S2 region at N-terminus of the S protein. Plant-derived recombinant M protein provoked stronger serum antibody responses against HBsAg than did S protein when injected systemically in mice. We discuss implications for use of fusion proteins for enhanced immunogenicity and mucosal targeting of HBsAg, as well as delivery of heterologous fused antigens. NVCP expressed in plants assembled 38 nm virion-size icosahedral (T = 3) VLP, similar to those produced in insect cells. The VLP stimulated serum IgG and IgA responses in mice and humans when they were delivered by ingestion of fresh potato tuber. Here we show that freeze-drying of transgenic NVCP tomato fruit yielded stable preparations that stimulated excellent IgG and IgA responses against NVCP when fed to mice. However, the predominant VLP form in tomato fruit was the small 23 nm particle also observed in insect cell-derived NVCP.

Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

PubMed

Burlet, E; HogenEsch, H; Dunham, A; Morefield, G

2017-05-01

Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

Immunogenicity and protective efficacy of heparan sulphate binding proteins of Entamoeba histolytica in a guinea pig model of intestinal amoebiasis.

PubMed

Kaur, Upninder; Khurana, Sumeeta; Saikia, Uma Nahar; Dubey, M L

2013-11-01

Entamoeba histolytica infection is associated with considerable morbidity and mortality in the form of intestinal and extraintestinal amoebiasis. No vaccine is yet available for amoebiasis. Heparan Sulphate Binding Proteins (HSBPs) from E. histolytica were evaluated for immunogenicity and protective efficacy in a Guinea pig model. Animals were immunized subcutaneously with 30μg of HSBP by three weekly inoculations. The immunogenicity of HSBP was determined by antibody response (IgG, IgM and IgA), splenocyte proliferation assay and in vitro direct amoebicidal assay with splenic lymphocytes and monocytes from vaccinated and control animals. The efficacy of the vaccine was evaluated by challenge infection to vaccinated and control animals by intra-caecal inoculation of E. histolytica trophozoites and comparing gross and histopathological findings in caeca of these animals. HSBP was found to induce specific anti-amoebic response as seen by specific antibody production and direct amoebicidal activity of splenocytes. The vaccine also showed partial protection against challenge infection in vaccinated animals as shown by mild/absent lesions and histopathological findings. Copyright © 2013 Elsevier Inc. All rights reserved.

Immunogenicity of therapeutic proteins: the use of animal models.

PubMed

Brinks, Vera; Jiskoot, Wim; Schellekens, Huub

2011-10-01

Immunogenicity of therapeutic proteins lowers patient well-being and drastically increases therapeutic costs. Preventing immunogenicity is an important issue to consider when developing novel therapeutic proteins and applying them in the clinic. Animal models are increasingly used to study immunogenicity of therapeutic proteins. They are employed as predictive tools to assess different aspects of immunogenicity during drug development and have become vital in studying the mechanisms underlying immunogenicity of therapeutic proteins. However, the use of animal models needs critical evaluation. Because of species differences, predictive value of such models is limited, and mechanistic studies can be restricted. This review addresses the suitability of animal models for immunogenicity prediction and summarizes the insights in immunogenicity that they have given so far.

Results of a study of the reactogenic and immunogenic properties of live anti-poliomyelitis vaccine

PubMed Central

Smorodintsev, A. A.; Davidenkova, E. F.; Drobyshevskaya, A. I.; Ilyenko, V. I.; Gorev, N. E.; Kurnosova, L. M.; Klyuchareva, T. E.

1959-01-01

The authors have studied the harmlessness and immunogenic properties of live poliomyelitis vaccine made in Leningrad from Sabin strains of low pathogenicity for monkeys. More than 20 000 children of pre-school (6 months to 3 years) and school age (7-14 years) were each given 100 000 tissue-culture infective doses of virus of types 1, 2 and 3, injected either in three stages at monthly intervals in the form of monovaccines, or in two stages, a monovaccine of type 1 being followed after a month's interval by injection of a divalent vaccine of types 2 and 3. The vaccination caused no symptoms of lesions of the central nervous system or other organs. In the blood of the inoculated children there was a regular build-up of virus-neutralizing antibodies to the serotypes mentioned, the intensity of which depended on the antibody level before vaccination and was in a constant relationship to the multiplication of the virus in the intestinal canal. The antibody titre was maintained at high levels for 6-9 months after immunization and fell a little after 12-18 months. The vaccinal virus is easily transferred from vaccinated children to contact groups, which are gradually vaccinated by this natural means. Lengthy and numerous passages of vaccinal strains through the intestinal canal of normal, susceptible children showed that strains may periodically appear which have a higher neurotropic activity for monkeys. This activity, however, did not increase in subsequent passage and returned to the initial level. PMID:13832218

Recombinant Zika virus envelope protein elicited protective immunity against Zika virus in immunocompetent mice

PubMed Central

Liu, Zhihua; Li, Min; Liu, Haitao

2018-01-01

Zika virus (ZIKV) has caused great public concerns due to its recent large outbreaks and a close association with microcephaly in fetus and Guillain-Barre syndrome in adults. Rapid development of vaccines against ZIKV is a public health priority. To this end, we have constructed and purified recombinant ZIKV envelope protein using both prokaryotic and eukaryotic expression systems, and then tested their immunogenicity and protective efficacy in immune competent mice. Both protein immunogens elicited humoral and cellular immune responses, and protected immune competent mice from ZIKV challenge in vivo. These products could be further evaluated either as stand-alone vaccine candidate, or used in a prime-and-boost regimen with other forms of ZIKV vaccine. PMID:29590178

The grafting of universal T-helper epitopes enhances immunogenicity of HIV-1 Tat concurrently improving its safety profile.

PubMed

Kashi, Venkatesh P; Jacob, Rajesh A; Shamanna, Raghavendra A; Menon, Malini; Balasiddaiah, Anangi; Varghese, Rebu K; Bachu, Mahesh; Ranga, Udaykumar

2014-01-01

Extracellular Tat (eTat) plays an important role in HIV-1 pathogenesis. The presence of anti-Tat antibodies is negatively correlated with disease progression, hence making Tat a potential vaccine candidate. The cytotoxicity and moderate immunogenicity of Tat however remain impediments for developing Tat-based vaccines. Here, we report a novel strategy to concurrently enhance the immunogenicity and safety profile of Tat. The grafting of universal helper T-lymphocyte (HTL) epitopes, Pan DR Epitope (PADRE) and Pol711 into the cysteine rich domain (CRD) and the basic domain (BD) abolished the transactivation potential of the Tat protein. The HTL-Tat proteins elicited a significantly higher titer of antibodies as compared to the wild-type Tat in BALB/c mice. While the N-terminal epitope remained immunodominant in HTL-Tat immunizations, an additional epitope in exon-2 was recognized with comparable magnitude suggesting a broader immune recognition. Additionally, the HTL-Tat proteins induced cross-reactive antibodies of high avidity that efficiently neutralized exogenous Tat, thus blocking the activation of a Tat-defective provirus. With advantages such as presentation of multiple B-cell epitopes, enhanced antibody response and importantly, transactivation-deficient Tat protein, this approach has potential application for the generation of Tat-based HIV/AIDS vaccines.

Immunogenicity of therapeutics: a matter of efficacy and safety.

PubMed

Nechansky, Andreas; Kircheis, Ralf

2010-11-01

The unwanted immunogenicity of therapeutic proteins is a major concern regarding patient safety. Furthermore, pharmacokinetic, pharmacodynamic and clinical efficacy can be seriously affected by the immunogenicity of therapeutic proteins. Authorities have fully recognized this issue and demand appropriate and well-characterized assays to detect anti-drug antibodies (ADAs). We provide an overview of the immunogenicity topic in general, the regulatory background and insight into underlying immunological mechanisms and the limited ability to predict clinical immunogenicity a priori. Furthermore, we comment on the analytical testing approach and the status-quo of appropriate method validation. The review provides insight regarding the analytical approach that is expected by regulatory authorities overseeing immunogenicity testing requirements. Additionally, the factors influencing immunogenicity are summarized and key references regarding immunogenicity testing approaches and method validation are discussed. The unwanted immunogenicity of protein therapeutics is of major concern because of its potential to affect patient safety and drug efficacy. Analytical testing is sophisticated and requires more than one assay. Because immunogenicity in humans is hardly predictable, assay development has to start in a timely fashion and for clinical studies immunogenicity assay validation is mandatory prior to analyzing patient serum samples. Regarding ADAs, the question remains as to when such antibodies are regarded of clinical relevance and what levels are, if at all, acceptable. In summary, the detection of ADAs should raise the awareness of the physician concerning patient safety and of the sponsor/manufacture concerning the immunogenic potential of the drug product.

Humoral immunity targeting site I of antigenic domain 2 of glycoprotein B upon immunization with different cytomegalovirus candidate vaccines.

PubMed

Axelsson, Fredrika; Adler, Stuart P; Lamarre, Alain; Ohlin, Mats

2007-12-21

Glycoprotein B (gB) is a major component in several vaccines that are under development for prevention of disease by cytomegalovirus. It contains multiple determinants that are targets for neutralizing antibodies. One of them is site I of antigenic domain 2 (AD-2). The epitope, defined by short peptides, is quite conserved between different isolates. However, it is poorly immunogenic in natural infection. In this study we investigated the extent to which different vaccines, attenuated live Towne vaccine with or without priming with a canarypox virus coding for gB, or a recombinant gB vaccine adjuvanted with MF59, induced antibodies to this epitope. As in natural infection only a fraction of all subjects developed antibody responses against site I of AD-2 following vaccination. We suggest that strategies that enhance immunogenicity of this epitope will improve vaccine efficacy.

Advances in vascular tissue engineering.

PubMed

Thomas, Anita C; Campbell, Gordon R; Campbell, Julie H

2003-01-01

Coronary and peripheral artery bypass grafting is commonly used to relieve the symptoms of vascular deficiencies, but the supply of autologous artery or vein may not be sufficient or suitable for multiple bypass or repeat procedures, necessitating the use of other materials. Synthetic materials are suitable for large bore arteries but often thrombose when used in smaller arteries. Suitable replacement grafts must have appropriate characteristics, including resistance to infection, low immunogenicity and good biocompatability and thromboresistance, with appropriate mechanical and physiological properties and cheap and fast manufacture. Current avenues of graft development include coating synthetic grafts with either biological chemicals or cells with anticoagulatory properties. Matrix templates or acellular tubes of extracellular matrix (such as collagen) may be coated or infiltrated with cultured cells. Once placed into the artery, these grafts may become colonised by host cells and gain many of the properties of normal artery. "Tissue-engineered blood vessels" may also be formed from layers of human vascular cells grown in culture. These engineered vessels have many of the characteristics of arteries formed in vivo. "Artificial arteries" may be also be derived from peritoneal granulation tissue in body "bioreactors" by adapting the body's natural wound healing response to produce a hollow tube.

Genetics and evolution of Yersinia pseudotuberculosis O-specific polysaccharides: a novel pattern of O-antigen diversity

PubMed Central

Kenyon, Johanna J.; Cunneen, Monica M.

2017-01-01

Abstract O-antigen polysaccharide is a major immunogenic feature of the lipopolysaccharide of Gram-negative bacteria, and most species produce a large variety of forms that differ substantially from one another. There are 18 known O-antigen forms in the Yersinia pseudotuberculosis complex, which are typical in being composed of multiple copies of a short oligosaccharide called an O unit. The O-antigen gene clusters are located between the hemH and gsk genes, and are atypical as 15 of them are closely related, each having one of five downstream gene modules for alternative main-chain synthesis, and one of seven upstream modules for alternative side-branch sugar synthesis. As a result, many of the genes are in more than one gene cluster. The gene order in each module is such that, in general, the earlier a gene product functions in O-unit synthesis, the closer the gene is to the 5΄ end for side-branch modules or the 3΄ end for main-chain modules. We propose a model whereby natural selection could generate the observed pattern in gene order, a pattern that has also been observed in other species. PMID:28364730

Identification of Rothia Bacteria as Gluten-Degrading Natural Colonizers of the Upper Gastro-Intestinal Tract

PubMed Central

Zamakhchari, Maram; Wei, Guoxian; Dewhirst, Floyd; Lee, Jaeseop; Schuppan, Detlef; Oppenheim, Frank G.; Helmerhorst, Eva J.

2011-01-01

Background Gluten proteins, prominent constituents of barley, wheat and rye, cause celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and the protease-resistant domains contain multiple immunogenic epitopes. The aim of this study was to identify novel sources of gluten-digesting microbial enzymes from the upper gastro-intestinal tract with the potential to neutralize gluten epitopes. Methodology/Principal Findings Oral microorganisms with gluten-degrading capacity were obtained by a selective plating strategy using gluten agar. Microbial speciations were carried out by 16S rDNA gene sequencing. Enzyme activities were assessed using gliadin-derived enzymatic substrates, gliadins in solution, gliadin zymography, and 33-mer α-gliadin and 26-mer γ-gliadin immunogenic peptides. Fragments of the gliadin peptides were separated by RP-HPLC and structurally characterized by mass spectrometry. Strains with high activity towards gluten were typed as Rothia mucilaginosa and Rothia aeria. Gliadins (250 µg/ml) added to Rothia cell suspensions (OD620 1.2) were degraded by 50% after ∼30 min of incubation. Importantly, the 33-mer and 26-mer immunogenic peptides were also cleaved, primarily C-terminal to Xaa-Pro-Gln (XPQ) and Xaa-Pro-Tyr (XPY). The major gliadin-degrading enzymes produced by the Rothia strains were ∼70–75 kDa in size, and the enzyme expressed by Rothia aeria was active over a wide pH range (pH 3–10). Conclusion/Significance While the human digestive enzyme system lacks the capacity to cleave immunogenic gluten, such activities are naturally present in the oral microbial enzyme repertoire. The identified bacteria may be exploited for physiologic degradation of harmful gluten peptides. PMID:21957450

Identification of Rothia bacteria as gluten-degrading natural colonizers of the upper gastro-intestinal tract.

PubMed

Zamakhchari, Maram; Wei, Guoxian; Dewhirst, Floyd; Lee, Jaeseop; Schuppan, Detlef; Oppenheim, Frank G; Helmerhorst, Eva J

2011-01-01

Gluten proteins, prominent constituents of barley, wheat and rye, cause celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and the protease-resistant domains contain multiple immunogenic epitopes. The aim of this study was to identify novel sources of gluten-digesting microbial enzymes from the upper gastro-intestinal tract with the potential to neutralize gluten epitopes. Oral microorganisms with gluten-degrading capacity were obtained by a selective plating strategy using gluten agar. Microbial speciations were carried out by 16S rDNA gene sequencing. Enzyme activities were assessed using gliadin-derived enzymatic substrates, gliadins in solution, gliadin zymography, and 33-mer α-gliadin and 26-mer γ-gliadin immunogenic peptides. Fragments of the gliadin peptides were separated by RP-HPLC and structurally characterized by mass spectrometry. Strains with high activity towards gluten were typed as Rothia mucilaginosa and Rothia aeria. Gliadins (250 µg/ml) added to Rothia cell suspensions (OD(620) 1.2) were degraded by 50% after ∼30 min of incubation. Importantly, the 33-mer and 26-mer immunogenic peptides were also cleaved, primarily C-terminal to Xaa-Pro-Gln (XPQ) and Xaa-Pro-Tyr (XPY). The major gliadin-degrading enzymes produced by the Rothia strains were ∼70-75 kDa in size, and the enzyme expressed by Rothia aeria was active over a wide pH range (pH 3-10). While the human digestive enzyme system lacks the capacity to cleave immunogenic gluten, such activities are naturally present in the oral microbial enzyme repertoire. The identified bacteria may be exploited for physiologic degradation of harmful gluten peptides.

Maternal Milk T Cells Drive Development of Transgenerational Th1 Immunity in Offspring Thymus.

PubMed

Ghosh, Mrinal K; Nguyen, Virginia; Muller, H Konrad; Walker, Ameae M

2016-09-15

Using multiple murine foster-nursing protocols, thereby eliminating placental transfer and allowing a distinction between dam- and pup-derived cells, we show that foster nursing by an immunized dam results in development of CD8(+) T cells in nonimmunized foster pups that are specific for Ags against which the foster dam was immunized (Mycobacterium tuberculosis or Candida albicans). We have dubbed this process "maternal educational immunity" to distinguish it from passive cellular immunity. Of the variety of maternal immune cells present in milk, only T cells were detected in pup tissues. Maternal T cells, a substantial percentage of which were CD4(+)MHC class II(+), accumulated in the pup thymus and spleen during the nursing period. Further analysis of maternal cells in the pup thymus showed that a proportion was positive for maternal immunogen-specific MHC class II tetramers. To determine the outcome of Ag presentation in the thymus, the maternal or foster pup origin of immunogen-responding CD8(+) cells in foster pup spleens was assessed. Whereas ∼10% were maternally derived in the first few weeks after weaning, all immunogen-responding CD8(+) T cells were pup derived by 12 wk of age. Pup-derived immunogen-responsive CD8(+) cells persisted until at least 1 y of age. Passive cellular immunity is well accepted and has been demonstrated in the human population. In this study, we show an arguably more important role for transferred immune cells: the direction of offspring T cell development. Harnessing maternal educational immunity through prepregnancy immunization programs has potential for improvement of infant immunity. Copyright © 2016 by The American Association of Immunologists, Inc.

Safety and immunogenicity of heterologous prime-boost immunization with viral-vectored malaria vaccines adjuvanted with Matrix-M™.

PubMed

Venkatraman, Navin; Anagnostou, Nicholas; Bliss, Carly; Bowyer, Georgina; Wright, Danny; Lövgren-Bengtsson, Karin; Roberts, Rachel; Poulton, Ian; Lawrie, Alison; Ewer, Katie; V S Hill, Adrian

2017-10-27

The use of viral vectors in heterologous prime-boost regimens to induce potent T cell responses in addition to humoral immunity is a promising vaccination strategy in the fight against malaria. We conducted an open-label, first-in-human, controlled Phase I study evaluating the safety and immunogenicity of Matrix-M adjuvanted vaccination with a chimpanzee adenovirus serotype 63 (ChAd63) prime followed by a modified vaccinia Ankara (MVA) boost eight weeks later, both encoding the malaria ME-TRAP antigenic sequence (a multiple epitope string fused to thrombospondin-related adhesion protein). Twenty-two healthy adults were vaccinated intramuscularly with either ChAd63-MVA ME-TRAP alone (n=6) or adjuvanted with 25μg (n=8) or 50μg (n=8) Matrix-M. Vaccinations appeared to be safe and generally well tolerated, with the majority of local and systemic adverse events being mild in nature. The addition of Matrix-M to the vaccine did not increase local reactogenicity; however, systemic adverse events were reported more frequently by volunteers who received adjuvanted vaccine in comparison to the control group. T cell ELISpot responses peaked at 7-days post boost vaccination with MVA ME-TRAP in all three groups. TRAP-specific IgG responses were highest at 28-days post boost with MVA ME-TRAP in all three groups. There were no differences in cellular and humoral immunogenicity at any of the time points between the control group and the adjuvanted groups. We demonstrate that Matrix-M can be safely used in combination with ChAd63-MVA ME-TRAP heterologous prime-boost immunization without any reduction in cellular or humoral immunogenicity. Clinical Trials Registration NCT01669512. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques▿

PubMed Central

Rosario, Maximillian; Hopkins, Richard; Fulkerson, John; Borthwick, Nicola; Quigley, Máire F.; Joseph, Joan; Douek, Daniel C.; Greenaway, Hui Yee; Venturi, Vanessa; Gostick, Emma; Price, David A.; Both, Gerald W.; Sadoff, Jerald C.; Hanke, Tomáš

2010-01-01

Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankara-vectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration. PMID:20375158

Comparative seroprevalence and immunogenicity of six rare serotype recombinant adenovirus vaccine vectors from subgroups B and D.

PubMed

Abbink, Peter; Lemckert, Angelique A C; Ewald, Bonnie A; Lynch, Diana M; Denholtz, Matthew; Smits, Shirley; Holterman, Lennart; Damen, Irma; Vogels, Ronald; Thorner, Anna R; O'Brien, Kara L; Carville, Angela; Mansfield, Keith G; Goudsmit, Jaap; Havenga, Menzo J E; Barouch, Dan H

2007-05-01

Recombinant adenovirus serotype 5 (rAd5) vector-based vaccines are currently being developed for both human immunodeficiency virus type 1 and other pathogens. The potential limitations associated with rAd5 vectors, however, have led to the construction of novel rAd vectors derived from rare Ad serotypes. Several rare serotype rAd vectors have already been described, but a detailed comparison of multiple rAd vectors from subgroups B and D has not previously been reported. Such a comparison is critical for selecting optimal rAd vectors for advancement into clinical trials. Here we describe the construction of three novel rAd vector systems from Ad26, Ad48, and Ad50. We report comparative seroprevalence and immunogenicity studies involving rAd11, rAd35, and rAd50 vectors from subgroup B; rAd26, rAd48, and rAd49 vectors from subgroup D; and rAd5 vectors from subgroup C. All six rAd vectors from subgroups B and D exhibited low seroprevalence in a cohort of 200 individuals from sub-Saharan Africa, and they elicited Gag-specific cellular immune responses in mice both with and without preexisting anti-Ad5 immunity. The rAd vectors from subgroup D were also evaluated using rhesus monkeys and were shown to be immunogenic after a single injection. The rAd26 vectors proved the most immunogenic among the rare serotype rAd vectors studied, although all rare serotype rAd vectors were still less potent than rAd5 vectors in the absence of anti-Ad5 immunity. These studies substantially expand the portfolio of rare serotype rAd vectors that may prove useful as vaccine vectors for the developing world.

Infective and inactivated filamentous phage as carriers for immunogenic peptides.

PubMed

Samoylova, Tatiana I; Norris, Mandy D; Samoylov, Alexandre M; Cochran, Anna M; Wolfe, Karen G; Petrenko, Valery A; Cox, Nancy R

2012-07-01

The focus of this study is on development of vaccines using filamentous phage as a delivery vector for immunogenic peptides. The use of phage as a carrier for immunogenic peptides provides significant benefits such as high immunogenicity, low production costs, and high stability of phage preparations. However, introduction of live recombinant phage into the environment might represent a potential ecological problem. This, for example, may occur when vaccines are used in oral or nasal formulations in field conditions for wild and feral animals. To address this issue, comparative studies of antigenic properties of live and inactivated (non-viable) phage were accomplished. Inactivated phage, if released, will not propagate and will degrade as any other protein. In these experiments, a model phage clone that was previously selected from a phage display library and shown to stimulate production of anti-sperm antibodies with contraceptive properties was used. Multiple methods of phage inactivation were tested, including drying, freezing, autoclaving, heating, and UV irradiation. Under studied conditions, heating at 76°C for 3h, UV irradiation, and autoclaving resulted in complete phage inactivation. Phage samples treated by heat and UV were characterized by spectrophotometry and electron microscopy. To test antigenicity, live and inactivated phage preparations were injected into mice and antibody responses assayed by ELISA. It was found that phage killed by heat causes little to no immune responses, probably due to destruction of phage particles. In contrast, UV-inactivated phage stimulated production of IgG serum antibodies at the levels comparable to live phage. Thus, vaccines formulated to include UV-inactivated filamentous phage might represent environmentally safe alternatives to live phage vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

Empirical fitness models for hepatitis C virus immunogen design

NASA Astrophysics Data System (ADS)

Hart, Gregory R.; Ferguson, Andrew L.

2015-12-01

Hepatitis C virus (HCV) afflicts 170 million people worldwide, 2%-3% of the global population, and kills 350 000 each year. Prophylactic vaccination offers the most realistic and cost effective hope of controlling this epidemic in the developing world where expensive drug therapies are not available. Despite 20 years of research, the high mutability of the virus and lack of knowledge of what constitutes effective immune responses have impeded development of an effective vaccine. Coupling data mining of sequence databases with spin glass models from statistical physics, we have developed a computational approach to translate clinical sequence databases into empirical fitness landscapes quantifying the replicative capacity of the virus as a function of its amino acid sequence. These landscapes explicitly connect viral genotype to phenotypic fitness, and reveal vulnerable immunological targets within the viral proteome that can be exploited to rationally design vaccine immunogens. We have recovered the empirical fitness landscape for the HCV RNA-dependent RNA polymerase (protein NS5B) responsible for viral genome replication, and validated the predictions of our model by demonstrating excellent accord with experimental measurements and clinical observations. We have used our landscapes to perform exhaustive in silico screening of 16.8 million T-cell immunogen candidates to identify 86 optimal formulations. By reducing the search space of immunogen candidates by over five orders of magnitude, our approach can offer valuable savings in time, expense, and labor for experimental vaccine development and accelerate the search for a HCV vaccine. Abbreviations: HCV—hepatitis C virus, HLA—human leukocyte antigen, CTL—cytotoxic T lymphocyte, NS5B—nonstructural protein 5B, MSA—multiple sequence alignment, PEG-IFN—pegylated interferon.

Bioinformatics analysis of single and multi-hybrid epitopes of GRA-1, GRA-4, GRA-6 and GRA-7 proteins to improve DNA vaccine design against Toxoplasma gondii.

PubMed

Shaddel, Minoo; Ebrahimi, Mansour; Tabandeh, Mohammad Reza

2018-06-01

Toxoplasma gondii , is a causative agent of morbidity and mortality in immunocompromised and congenitally-infected individuals. Attempts to construct DNA vaccines against T. gondii using surface proteins are increasing. The dense granule antigens are highly expressed in the acute and chronic phases of T. gondii infection and considered as suitable DNA vaccine candidates to control toxoplasmosis. In the present study, bioinformatics tools and online software were used to predict, analyze and compare the structural, physical and chemical characters and immunogenicity of the GRA-1, GRA-4, GRA-6 and GRA-7 proteins. Sequence alignment results indicated that the GRA-1, GRA-4, GRA-6 and GRA-7 proteins had low similarity. The secondary structure prediction demonstrated that among the four proteins, GRA-1 and GRA-6 had similar secondary structure except for a little discrepancy. Hydrophilicity/hydrophobicity analysis showed multiple hydrophilic regions and some classical high hydrophilic domains for each protein sequence. Immunogenic epitope prediction results demonstrated that the GRA-1 and GRA-4 epitopes were stable and GRA-4 showed the highest degree of antigenicity. Although the GRA-7 epitope had the highest score of immunogenicity, this epitope was instable and had the lowest degree of antigenicity and half-time in eukaryotic cell. Also, the results indicated that GRA4-GRA7 epitope and GRA6-GRA7 had the highest degree of antigenicity and immunogenicity among multi-hybrid epitopes, respectively. Totally, in the present study, single epitopes showed the highest degree of antigenicity compared with multi-hybrid epitopes. Given the results, it can be concluded that GRA-4 and GRA-7 can be powerful DNA vaccine candidates against T. gondii .

Novel Injectable Pentablock Copolymer Based Thermoresponsive Hydrogels for Sustained Release Vaccines.

PubMed

Bobbala, Sharan; Tamboli, Viral; McDowell, Arlene; Mitra, Ashim K; Hook, Sarah

2016-01-01

The need for multiple vaccinations to enhance the immunogenicity of subunit vaccines may be reduced by delivering the vaccine over an extended period of time. Here, we report two novel injectable pentablock copolymer based thermoresponsive hydrogels made of polyethyleneglycol-polycaprolactone-polylactide-polycaprolactone-polyethyleneglycol (PEG-PCL-PLA-PCL-PEG) with varying ratios of polycaprolactone (PCL) and polylactide (PLA), as single shot sustained release vaccines. Pentablock copolymer hydrogels were loaded with vaccine-encapsulated poly lactic-co-glycolic acid nanoparticles (PLGA-NP) or with the soluble vaccine components. Incorporation of PLGA-NP into the thermoresponsive hydrogels increased the complex viscosity of the gels, lowered the gelation temperature, and minimized the burst release of antigen and adjuvants. The two pentablock hydrogels stimulated both cellular and humoral responses. The addition of PLGA-NP to the hydrogels sustained immune responses for up to 49 days. The polymer with a higher ratio of PCL to PLA formed a more rigid gel, induced stronger immune responses, and stimulated effective anti-tumor responses in a prophylactic melanoma tumor model.

Tryptophan 375 stabilizes the outer-domain core of gp120 for HIV vaccine immunogen design.

PubMed

Hu, Duoyi; Bowder, Dane; Wei, Wenzhong; Thompson, Jesse; Wilson, Mark A; Xiang, Shi-Hua

2017-05-25

The outer-domain core of gp120 may serve as a better HIV vaccine immunogen than the full-length gp120 because of its greater stability and immunogenicity. In our previous report, we introduced two disulfide bonds to the outer-domain core of gp120 to fix its conformation into a CD4-bound state, which resulted in a significant increase in its immunogenicity when compared to the wild-type outer-domain core. In this report, to further improve the immunogenicity of the outer-domain core based immunogen, we have introduced a Tryptophan residue at gp120 amino acid sequence position 375 (375S/W). Our data from immunized guinea pigs indeed shows a striking increase in the immune response due to this stabilized core outer-domain. Therefore, we conclude that the addition of 375W to the outer-domain core of gp120 further stabilizes the structure of immunogen and increases the immunogenicity. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Foreignness as a matter of degree: the relative immunogenicity of peptide/MHC ligands.

PubMed

van den Berg, Hugo A; Rand, David A

2004-12-21

The ability of T lymphocytes (T cells) to recognize and attack foreign invaders while leaving healthy cells unharmed is often analysed as a discrete self/non-self dichotomy, with each peptide/MHC ligand classified as either self or non-self. We argue that the ligand immunogenicity is more naturally treated as a continuous quantity, and show how to define and quantitate relative ligand immunogenicity. In our theory, self-tolerance is acquired through reduction of the relative immunogenicity of autoantigens, whereas xenoantigens, typically not presented during induction of deletional tolerance, retain a high degree of relative immunogenicity. Autoantigens that are not prominently presented in deletional tolerance likewise retain a high relative immunogenicity and remain essentially foreign. According to our analysis, any given autoantigen can attain a high level of relative immunogenicity, provided it is presented at sufficiently high levels. Our theory provides a quantitative tool to analyse the immunogenicity of tumour-associated neoantigens and the aetiology of autoimmune disease.

11th GCC Closed Forum: cumulative stability; matrix stability; immunogenicity assays; laboratory manuals; biosimilars; chiral methods; hybrid LBA/LCMS assays; fit-for-purpose validation; China Food and Drug Administration bioanalytical method validation.

PubMed

Islam, Rafiq; Briscoe, Chad; Bower, Joseph; Cape, Stephanie; Arnold, Mark; Hayes, Roger; Warren, Mark; Karnik, Shane; Stouffer, Bruce; Xiao, Yi Qun; van der Strate, Barry; Sikkema, Daniel; Fang, Xinping; Tudoroniu, Ariana; Tayyem, Rabab; Brant, Ashley; Spriggs, Franklin; Barry, Colin; Khan, Masood; Keyhani, Anahita; Zimmer, Jennifer; Caturla, Maria Cruz; Couerbe, Philippe; Khadang, Ardeshir; Bourdage, James; Datin, Jim; Zemo, Jennifer; Hughes, Nicola; Fatmi, Saadya; Sheldon, Curtis; Fountain, Scott; Satterwhite, Christina; Colletti, Kelly; Vija, Jenifer; Yu, Mathilde; Stamatopoulos, John; Lin, Jenny; Wilfahrt, Jim; Dinan, Andrew; Ohorodnik, Susan; Hulse, James; Patel, Vimal; Garofolo, Wei; Savoie, Natasha; Brown, Michael; Papac, Damon; Buonarati, Mike; Hristopoulos, George; Beaver, Chris; Boudreau, Nadine; Williard, Clark; Liu, Yansheng; Ray, Gene; Warrino, Dominic; Xu, Allan; Green, Rachel; Hayward-Sewell, Joanne; Marcelletti, John; Sanchez, Christina; Kennedy, Michael; Charles, Jessica St; Bouhajib, Mohammed; Nehls, Corey; Tabler, Edward; Tu, Jing; Joyce, Philip; Iordachescu, Adriana; DuBey, Ira; Lindsay, John; Yamashita, Jim; Wells, Edward

2018-04-01

The 11th Global CRO Council Closed Forum was held in Universal City, CA, USA on 3 April 2017. Representatives from international CRO members offering bioanalytical services were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The second CRO-Pharma Scientific Interchange Meeting was held on 7 April 2017, which included Pharma representatives' sharing perspectives on the topics discussed earlier in the week with the CRO members. The issues discussed at the meetings included cumulative stability evaluations, matrix stability evaluations, the 2016 US FDA Immunogenicity Guidance and recent and unexpected FDA Form 483s on immunogenicity assays, the bioanalytical laboratory's role in writing PK sample collection instructions, biosimilars, CRO perspectives on the use of chiral versus achiral methods, hybrid LBA/LCMS assays, applications of fit-for-purpose validation and, at the Global CRO Council Closed Forum only, the status and trend of current regulated bioanalytical practice in China under CFDA's new BMV policy. Conclusions from discussions of these topics at both meetings are included in this report.

An efficient method for native protein purification in the selected range from prostate cancer tissue digests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Rumana; Nicora, Carrie D.; Shukla, Anil K.

Prostate cancer (CP) cells differ from their normal counterpart in gene expression. Genes encoding secreted or extracellular proteins with increased expression in CP may serve as potential biomarkers. For their detection and quantification, assays based on monoclonal antibodies are best suited for development in a clinical setting. One approach to obtain antibodies is to use recombinant proteins as immunogen. However, the synthesis of recombinant protein for each identified candidate is time-consuming and expensive. It is also not practical to generate high quality antibodies to all identified candidates individually. Furthermore, non-native forms (e.g., recombinant) of proteins may not always lead tomore » useful antibodies. Our approach was to purify a subset of proteins from CP tissue specimens for use as immunogen.« less

Modeling of 3D Structure of Chimeric Constructs Based on Hemagglutinin of Influenza Virus and Immunogenic Epitopes of Streptococcus Agalactiae.

PubMed

Fedorova, E A; Smolonogina, T A; Isakova-Sivak, I N; Koren'kov, D A; Kotomina, T S; Leont'eva, G F; Suvorov, A N; Rudenko, L G

2018-04-01

A project of an experimental recombinant vector vaccine for prevention of diseases caused by pathogenic streptococci based on ScaAB lipoprotein of Streptococcus agalactiae and a coldadapted strain of live influenza vaccine as a vector was developed. The sequence of ScaAB lipoprotein was analyzed and fragments forming immunodominant epitopes were determined. Chimeric molecules of influenza virus hemagglutinin H7 carrying insertions of bacterial origin were constructed. Based on the results of simulation, the most promising variants were selected; they represented fragments of lipoprotein ScaAB lacking N-terminal domain bound to hemagglutinin via a flexible linker. These insertions should minimally modulate the properties of the influenza strain, while retaining potential immunogenicity to a wide group of pathogenic streptococci.

Development of replication-competent viral vectors for HIV vaccine delivery

PubMed Central

Parks, Christopher L.; Picker, Louis J.; King, C. Richter

2014-01-01

Purpose of review Briefly describe some of the replication-competent (RC) vectors being investigated for development of candidate HIV vaccines focusing primarily on technologies that have advanced to testing in macaques or have entered clinical trials. Recent findings RC viral vectors have advanced to the stage were decisions can be made regarding future development of HIV vaccines. The viruses being used as RC vector platforms vary considerably, and their unique attributes make it possible to test multiple vaccine design concepts and also mimic various aspects of an HIV infection. RC viral vectors encoding SIV or HIV proteins can be used to safely immunize macaques, and in some cases, there is evidence of significant vaccine efficacy in challenge protection studies. Several live HIV vaccine vectors are in clinical trials to evaluate immunogenicity, safety, the effect of mucosal delivery, and potential effects of pre-existing immunity. Summary A variety of DNA and RNA viruses are being used to develop RC viral vectors for HIV vaccine delivery. Multiple viral vector platforms have proven to be safe and immunogenic with evidence of efficacy in macaques. Some of the more advanced HIV vaccine prototypes based on vesicular stomatitis virus, vaccinia virus, measles virus, and Sendai virus are in clinical trials. PMID:23925000

Evaluation of a Salmonella Strain Lacking the Secondary Messenger C-di-GMP and RpoS as a Live Oral Vaccine

PubMed Central

García, Begoña; Gil, Carmen; García-Ona, Enrique; Burgui, Saioa; Casares, Noelia; Hervás-Stubbs, Sandra; Lasarte, Juan José; Lasa, Iñigo

2016-01-01

Salmonellosis is one of the most important bacterial zoonotic diseases transmitted through the consumption of contaminated food, with chicken and pig related products being key reservoirs of infection. Although numerous studies on animal vaccination have been performed in order to reduce Salmonella prevalence, there is still a need for an ideal vaccine. Here, with the aim of constructing a novel live attenuated Salmonella vaccine candidate, we firstly analyzed the impact of the absence of cyclic-di-GMP (c-di-GMP) in Salmonella virulence. C-di-GMP is an intracellular second messenger that controls a wide range of bacterial processes, including biofilm formation and synthesis of virulence factors, and also modulates the host innate immune response. Our results showed that a Salmonella multiple mutant in the twelve genes encoding diguanylate cyclase proteins that, as a consequence, cannot synthesize c-di-GMP, presents a moderate attenuation in a systemic murine infection model. An additional mutation of the rpoS gene resulted in a synergic attenuating effect that led to a highly attenuated strain, referred to as ΔXIII, immunogenic enough to protect mice against a lethal oral challenge of a S. Typhimurium virulent strain. ΔXIII immunogenicity relied on activation of both antibody and cell mediated immune responses characterized by the production of opsonizing antibodies and the induction of significant levels of IFN-γ, TNF-α, IL-2, IL-17 and IL-10. ΔXIII was unable to form a biofilm and did not survive under desiccation conditions, indicating that it could be easily eliminated from the environment. Moreover, ΔXIII shows DIVA features that allow differentiation of infected and vaccinated animals. Altogether, these results show ΔXIII as a safe and effective live DIVA vaccine. PMID:27537839

Nucleic acids encoding modified human immunodeficiency virus type 1 (HIV-1) group M consensus envelope glycoproteins

DOEpatents

Haynes, Barton F [Durham, NC; Gao, Feng [Durham, NC; Korber, Bette T [Los Alamos, NM; Hahn, Beatrice H [Birmingham, AL; Shaw, George M [Birmingham, AL; Kothe, Denise [Birmingham, AL; Li, Ying Ying [Hoover, AL; Decker, Julie [Alabaster, AL; Liao, Hua-Xin [Chapel Hill, NC

2011-12-06

The present invention relates, in general, to an immunogen and, in particular, to an immunogen for inducing antibodies that neutralizes a wide spectrum of HIV primary isolates and/or to an immunogen that induces a T cell immune response. The invention also relates to a method of inducing anti-HIV antibodies, and/or to a method of inducing a T cell immune response, using such an immunogen. The invention further relates to nucleic acid sequences encoding the present immunogens.

Murine immunization with CS21 pili or LngA major subunit of enterotoxigenic Escherichia coli (ETEC) elicits systemic and mucosal immune responses and inhibits ETEC gut colonization.

PubMed

Zhang, Chengxian; Iqbal, Junaid; Gómez-Duarte, Oscar G

2017-04-01

CS21 pili of enterotoxigenic Escherichia coli (ETEC) is one of the most prevalent ETEC colonization factors. CS21 major subunit, LngA, mediates ETEC adherence to intestinal cells, and contributes to ETEC pathogenesis in a neonatal mouse infection model. The objectives of this work were to evaluate LngA major subunit purified protein and CS21 purified pili on immunogenicity and protection against ETEC colonization of mice intestine. Recombinant LngA purified protein or purified CS21 pili from E9034A ETEC strain were evaluated for immunogenicity after immunization of C57BL/6 mice. Specific anti-LngA antibodies were detected from mice serum, feces, and intestine fluid samples by ELISA assays. Protection against gut colonization was evaluated on immunized mice orally challenged with wild type E9034A ETEC strain and by subsequent quantification of bacterial colony forming units (CFU) recovered from feces. Recombinant LngA protein and CS21 pili induced specific humoral and mucosal anti-LngA antibodies in the mouse model. CS21 combined with CT delivered intranasally as well as LngA combined with incomplete Freund adjuvant delivered intraperitoneally inhibited ETEC gut colonization in a mouse model. In conclusion, both LngA purified protein and CS21 pili from ETEC are highly immunogenic and may inhibit ETEC intestinal shedding. Our data on immunogenicity and immunoprotection indicates that CS21 is a suitable vaccine candidate for a future multivalent vaccine against ETEC diarrhea. Copyright © 2016 Elsevier B.V. All rights reserved.

ORFeome Phage Display.

PubMed

Zantow, Jonas; Moreira, Gustavo Marçal Schmidt Garcia; Dübel, Stefan; Hust, Michael

2018-01-01

ORFeome phage display allows the efficient functional screening of entire proteomes or even metaproteomes to identify immunogenic proteins. For this purpose, randomly fragmented, whole genomes or metagenomes are cloned into a phage-display vector allowing positive selection for open reading frames (ORF) to improve the library quality. These libraries display all possible proteins encoded by a pathogen or a microbiome on the phage surface. Consequently, immunogenic proteins can be selected from these libraries using disease-related immunoglobulins from patient serum. ORFeome phage display in particular allows the identification of immunogenic proteins that are only expressed in the host-pathogen interaction but not in cultivation, as well as the detection of very low expressed and very small immunogens and immunogenic proteins of non-cultivable organisms. The identified immunogenic proteins are potential biomarkers for the development of diagnostic assays or vaccines. These articles will give an introduction to ORFeome phage-display technology and give detailed protocols to identify immunogenic proteins by phage display.

The inducers of immunogenic cell death for tumor immunotherapy.

PubMed

Li, Xiuying

2018-01-01

Immunotherapy is a promising treatment modality that acts by selectively harnessing the host immune defenses against cancer. An effective immune response is often needed to eliminate tumors following treatment which can trigger the immunogenicity of dying tumor cells. Some treatment modalities (such as photodynamic therapy, high hydrostatic pressure or radiotherapy) and agents (some chemotherapeutic agents, oncolytic viruses) have been used to endow tumor cells with immunogenicity and/or increase their immunogenicity. These treatments and agents can boost the antitumor capacity by inducing immune responses against tumor neoantigens. Immunogenic cell death is a manner of cell death that can induce the emission of immunogenic damage-associated molecular patterns (DAMPs). DAMPs are sufficient for immunocompetent hosts to trigger the immune system. This review focuses on the latest developments in the treatment modalities and agents that can induce and/or enhance the immunogenicity of cancer cells.

Development of TaqMan probes targeting the four major celiac disease epitopes found in α-gliadin sequences of spelt (Triticum aestivum ssp. spelta) and bread wheat (Triticum aestivum ssp. aestivum).

PubMed

Dubois, Benjamin; Bertin, Pierre; Muhovski, Yordan; Escarnot, Emmanuelle; Mingeot, Dominique

2017-01-01

Celiac disease (CD) is caused by specific sequences of gluten proteins found in cereals such as bread wheat ( Triticum aestivum ssp. aestivum ) and spelt ( T. aestivum ssp. spelta ). Among them, the α-gliadins display the highest immunogenicity, with four T-cell stimulatory epitopes. The toxicity of each epitope sequence can be reduced or even suppressed according to the allelic form of each sequence. One way to address the CD problem would be to make use of this allelic variability in breeding programs to develop safe varieties, but tools to track the presence of toxic epitopes are required. The objective of this study was to develop a tool to accurately detect and quantify the immunogenic content of expressed α-gliadins of spelt and bread wheat. Four TaqMan probes that only hybridize to the canonical-i.e. toxic-form of each of the four epitopes were developed and their specificity was demonstrated. Six TaqMan probes targeting stable reference genes were also developed and constitute a tool to normalize qPCR data. The probes were used to measure the epitope expression levels of 11 contrasted spelt accessions and three ancestral diploid accessions of bread wheat and spelt. A high expression variability was highlighted among epitopes and among accessions, especially in Asian spelts, which showed lower epitope expression levels than the other spelts. Some discrepancies were identified between the canonical epitope expression level and the global amount of expressed α-gliadins, which makes the designed TaqMan probes a useful tool to quantify the immunogenic potential independently of the global amount of expressed α-gliadins. The results obtained in this study provide useful tools to study the immunogenic potential of expressed α-gliadin sequences from Triticeae accessions such as spelt and bread wheat. The application of the designed probes to contrasted spelt accessions revealed a high variability and interesting low canonical epitope expression levels in the Asian spelt accessions studied.

Nanosecond-Pulsed DBD Plasma-Generated Reactive Oxygen Species Trigger Immunogenic Cell Death in A549 Lung Carcinoma Cells through Intracellular Oxidative Stress

PubMed Central

Lin, Abraham; Truong, Billy; Patel, Sohil; Kaushik, Nagendra; Choi, Eun Ha; Fridman, Gregory; Fridman, Alexander; Miller, Vandana

2017-01-01

A novel application for non-thermal plasma is the induction of immunogenic cancer cell death for cancer immunotherapy. Cells undergoing immunogenic death emit danger signals which facilitate anti-tumor immune responses. Although pathways leading to immunogenic cell death are not fully understood; oxidative stress is considered to be part of the underlying mechanism. Here; we studied the interaction between dielectric barrier discharge plasma and cancer cells for oxidative stress-mediated immunogenic cell death. We assessed changes to the intracellular oxidative environment after plasma treatment and correlated it to emission of two danger signals: surface-exposed calreticulin and secreted adenosine triphosphate. Plasma-generated reactive oxygen and charged species were recognized as the major effectors of immunogenic cell death. Chemical attenuators of intracellular reactive oxygen species successfully abrogated oxidative stress following plasma treatment and modulated the emission of surface-exposed calreticulin. Secreted danger signals from cells undergoing immunogenic death enhanced the anti-tumor activity of macrophages. This study demonstrated that plasma triggers immunogenic cell death through oxidative stress pathways and highlights its potential development for cancer immunotherapy. PMID:28467380

Improved Prefusion Stability, Optimized Codon Usage, and Augmented Virion Packaging Enhance the Immunogenicity of Respiratory Syncytial Virus Fusion Protein in a Vectored-Vaccine Candidate

PubMed Central

Liang, Bo; Ngwuta, Joan O.; Surman, Sonja; Kabatova, Barbora; Liu, Xiang; Lingemann, Matthias; Liu, Xueqiao; Yang, Lijuan; Herbert, Richard; Swerczek, Joanna; Chen, Man; Moin, Syed M.; Kumar, Azad; McLellan, Jason S.; Kwong, Peter D.; Graham, Barney S.; Collins, Peter L.

2017-01-01

ABSTRACT Respiratory syncytial virus (RSV) is the most important viral agent of severe pediatric respiratory tract disease worldwide, but it lacks a licensed vaccine or suitable antiviral drug. A live attenuated chimeric bovine/human parainfluenza virus type 3 (rB/HPIV3) was developed previously as a vector expressing RSV fusion (F) protein to confer bivalent protection against RSV and HPIV3. In a previous clinical trial in virus-naive children, rB/HPIV3 was well tolerated but the immunogenicity of wild-type RSV F was unsatisfactory. We previously modified RSV F with a designed disulfide bond (DS) to increase stability in the prefusion (pre-F) conformation and to be efficiently packaged in the vector virion. Here, we further stabilized pre-F by adding both disulfide and cavity-filling mutations (DS-Cav1), and we also modified RSV F codon usage to have a lower CpG content and a higher level of expression. This RSV F open reading frame was evaluated in rB/HPIV3 in three forms: (i) pre-F without vector-packaging signal, (ii) pre-F with vector-packaging signal, and (iii) secreted pre-F ectodomain trimer. Despite being efficiently expressed, the secreted pre-F was poorly immunogenic. DS-Cav1 stabilized pre-F, with or without packaging, induced higher titers of pre-F specific antibodies in hamsters, and improved the quality of RSV-neutralizing serum antibodies. Codon-optimized RSV F containing fewer CpG dinucleotides had higher F expression, replicated more efficiently in vivo, and was more immunogenic. The combination of DS-Cav1 pre-F stabilization, optimized codon usage, reduced CpG content, and vector packaging significantly improved vector immunogenicity and protective efficacy against RSV. This provides an improved vectored RSV vaccine candidate suitable for pediatric clinical evaluation. IMPORTANCE RSV and HPIV3 are the first and second leading viral causes of severe pediatric respiratory disease worldwide. Licensed vaccines or suitable antiviral drugs are not available. We are developing a chimeric rB/HPIV3 vector expressing RSV F as a bivalent RSV/HPIV3 vaccine and have been evaluating means to increase RSV F immunogenicity. In this study, we evaluated the effects of improved stabilization of F in the pre-F conformation and of codon optimization resulting in reduced CpG content and greater pre-F expression. Reduced CpG content dampened the interferon response to infection, promoting higher replication and increased F expression. We demonstrate that improved pre-F stabilization and strategic manipulation of codon usage, together with efficient pre-F packaging into vector virions, significantly increased F immunogenicity in the bivalent RSV/HPIV3 vaccine. The improved immunogenicity included induction of increased titers of high-quality complement-independent antibodies with greater pre-F site Ø binding and greater protection against RSV challenge. PMID:28539444

Allergenicity, immunogenicity and dose-relationship of three intact allergen vaccines and four allergoid vaccines for subcutaneous grass pollen immunotherapy.

PubMed

Henmar, H; Lund, G; Lund, L; Petersen, A; Würtzen, P A

2008-09-01

Different vaccines containing intact allergens or chemically modified allergoids as active ingredients are commercially available for specific immunotherapy. Allergoids are claimed to have decreased allergenicity without loss of immunogenicity and this is stated to allow administration of high allergoid doses. We compared the allergenicity and immunogenicity of four commercially available chemically modified grass pollen allergoid products with three commercially available intact grass pollen allergen vaccines. The allergenicity was investigated with immunoglobulin (Ig)E-inhibition and basophil activation assays. Human T cell proliferation and specific IgG-titres following mouse immunizations were used to address immunogenicity. Furthermore, intact allergen vaccines with different contents of active ingredients were selected to study the influence of the allergen dose. In general, a lower allergenicity for allergen vaccines was clearly linked to a reduced immunogenicity. Compared with the vaccine with the highest amount of intact allergen, the allergoids caused reduced basophil activation as well as diminished immunogenicity demonstrated by reduced T cell activation and/or reduced induction of murine grass-specific IgG antibodies. Interestingly, intact allergen vaccines with lower content of active ingredient exhibited similarly reduced allergenicity, while immunogenicity was still higher or equal to that of allergoids. The low allergenicity observed for some allergoids was inherently linked to a significantly lower immunogenic response questioning the rationale behind the chemical modification into allergoids. In addition, the linkage between allergenicity, immunogenicity and dose found for intact allergen vaccines and the immunogen as well as allergenic immune responses observed for allergoids suggest that the modified allergen vaccines do not contain high doses of immunologically active ingredients.

Properties of MHC Class I Presented Peptides That Enhance Immunogenicity

PubMed Central

Calis, Jorg J. A.; Maybeno, Matt; Greenbaum, Jason A.; Weiskopf, Daniela; De Silva, Aruna D.; Sette, Alessandro; Keşmir, Can; Peters, Bjoern

2013-01-01

T-cells have to recognize peptides presented on MHC molecules to be activated and elicit their effector functions. Several studies demonstrate that some peptides are more immunogenic than others and therefore more likely to be T-cell epitopes. We set out to determine which properties cause such differences in immunogenicity. To this end, we collected and analyzed a large set of data describing the immunogenicity of peptides presented on various MHC-I molecules. Two main conclusions could be drawn from this analysis: First, in line with previous observations, we showed that positions P4–6 of a presented peptide are more important for immunogenicity. Second, some amino acids, especially those with large and aromatic side chains, are associated with immunogenicity. This information was combined into a simple model that was used to demonstrate that immunogenicity is, to a certain extent, predictable. This model (made available at http://tools.iedb.org/immunogenicity/) was validated with data from two independent epitope discovery studies. Interestingly, with this model we could show that T-cells are equipped to better recognize viral than human (self) peptides. After the past successful elucidation of different steps in the MHC-I presentation pathway, the identification of variables that influence immunogenicity will be an important next step in the investigation of T-cell epitopes and our understanding of cellular immune responses. PMID:24204222

Polyvalent immunogen

DOEpatents

Haynes, Barton F [Durham, NC; Korber, Bette T [Los Alamos, NM; De Lorimier, Robert M [Durham, NC; Liao, Hua-Xin [Chapel Hill, NC

2007-02-06

The present invention relates, generally, to a polyvalent immunogen and, more particularly, to a method of inducing neutralizing antibodies against HIV and to a polyvalent immunogen suitable for use in such a method.

Polyvalent immunogen

DOEpatents

Haynes, Barton F [Durham, NC; Korber, Bette T [Los Alamos, NM; De Lorimier, Robert M [Durham, NC

2007-03-27

The present invention relates, generally, to a polyvalent immunogen and, more particularly, to a method of inducing neutralizing antibodies against HIV and to a polyvalent immunogen suitable for use in such a method.

Vaccination with dendritic cells pulsed with hepatitis C pseudo particles induces specific immune responses in mice

PubMed Central

Weigand, Kilian; Voigt, Franziska; Encke, Jens; Hoyler, Birgit; Stremmel, Wolfgang; Eisenbach, Christoph

2012-01-01

AIM: To explore dendritic cells (DCs) multiple functions in immune modulation. METHODS: We used bone-marrow derived dendritic cells from BALB/c mice pulsed with pseudo particles from the hepatitis C virus to vaccinate naive BALB/c mice. Hepatitis C virus (HCV) pseudo particles consist of the genotype 1b derived envelope proteins E1 and E2, covering a non-HCV core structure. Thus, not a single epitope, but the whole “viral surface” induces immunogenicity. For vaccination, mature and activated DC were injected subcutaneously twice. RESULTS: Humoral and cellular immune responses measured by enzyme-linked immunosorbent assay and interferon-gamma enzyme-linked immunosorbent spot test showed antibody production as well as T-cells directed against HCV. Furthermore, T-cell responses confirmed two highly immunogenic regions in E1 and E2 outside the hypervariable region 1. CONCLUSION: Our results indicate dendritic cells as a promising vaccination model for HCV infection that should be evaluated further. PMID:22371638

Identification of Immunogenic Hot Spots within Plum Pox Potyvirus Capsid Protein for Efficient Antigen Presentation

PubMed Central

Fernández-Fernández, M. Rosario; Martínez-Torrecuadrada, Jorge L.; Roncal, Fernando; Domínguez, Elvira; García, Juan Antonio

2002-01-01

PEPSCAN analysis has been used to characterize the immunogenic regions of the capsid protein (CP) in virions of plum pox potyvirus (PPV). In addition to the well-known highly immunogenic N- and C-terminal domains of CP, regions within the core domain of the protein have also shown high immunogenicity. Moreover, the N terminus of CP is not homogeneously immunogenic, alternatively showing regions frequently recognized by antibodies and others that are not recognized at all. These results have helped us to design efficient antigen presentation vectors based on PPV. As predicted by PEPSCAN analysis, a small displacement of the insertion site in a previously constructed vector, PPV-γ, turned the derived chimeras into efficient immunogens. Vectors expressing foreign peptides at different positions within a highly immunogenic region (amino acids 43 to 52) in the N-terminal domain of CP were the most effective at inducing specific antibody responses against the foreign sequence. PMID:12438590

Expression and characterization of a novel truncated rotavirus VP4 for the development of a recombinant rotavirus vaccine.

PubMed

Li, Yijian; Xue, Miaoge; Yu, Linqi; Luo, Guoxing; Yang, Han; Jia, Lianzhi; Zeng, Yuanjun; Li, Tingdong; Ge, Shengxiang; Xia, Ningshao

2018-04-12

The outer capsid protein VP4 is an important target for the development of a recombinant rotavirus vaccine because it mediates the attachment and penetration of rotavirus. Due to the poor solubility of full-length VP4, VP8 was explored as candidate rotavirus vaccines in the past years. In previous studies, it has been found that the N-terminal truncated VP8 protein, VP8-1 (aa26-231), could be expressed in soluble form with improved immunogenicity compared to the core of VP8 (aa65-223). However, this protein stimulated only a weak immune response when aluminum hydroxide was used as an adjuvant. In addition, it should be noted that the protective efficacy of VP4 was higher than that of VP8 and VP5. In this study, it was found that when the N-terminal 25 amino acids were deleted, the truncated VP4 ∗ (aa26-476) containing VP8 and the stalk domain of VP5 could be expressed in soluble form in E. coli and purified to homogeneous trimers. Furthermore, the truncated VP4 could induce high titers of neutralizing antibodies when aluminum adjuvant was used and conferred high protective efficacy in reducing the severity of diarrhea and rotavirus shedding in stools in animal models. The immunogenicity of the truncated VP4 was significantly higher than that of VP8 ∗ and VP5 ∗ alone. Taken together, the truncated VP4 ∗ (aa26-476), with enhanced immunogenicity and immunoprotectivity, could be considered as a viable candidate for further development and has the potential to become a parenterally administered rotavirus vaccine. Copyright © 2018 Elsevier Ltd. All rights reserved.

Structural constraints-based evaluation of immunogenic avirulent toxins from Clostridium botulinum C2 and C3 toxins as subunit vaccines.

PubMed

Prisilla, A; Prathiviraj, R; Sasikala, R; Chellapandi, P

2016-10-01

Clostridium botulinum (group-III) is an anaerobic bacterium producing C2 and C3 toxins in addition to botulinum neurotoxins in avian and mammalian cells. C2 and C3 toxins are members of bacterial ADP-ribosyltransferase superfamily, which modify the eukaryotic cell surface proteins by ADP-ribosylation reaction. Herein, the mutant proteins with lack of catalytic and pore forming function derived from C2 (C2I and C2II) and C3 toxins were computationally evaluated to understand their structure-function integrity. We have chosen many structural constraints including local structural environment, folding process, backbone conformation, conformational dynamic sub-space, NAD-binding specificity and antigenic determinants for screening of suitable avirulent toxins. A total of 20 avirulent mutants were identified out of 23 mutants, which were experimentally produced by site-directed mutagenesis. No changes in secondary structural elements in particular to α-helices and β-sheets and also in fold rate of all-β classes. Structural stability was maintained by reordered hydrophobic and hydrogen bonding patterns. Molecular dynamic studies suggested that coupled mutations may restrain the binding affinity to NAD(+) or protein substrate upon structural destabilization. Avirulent toxins of this study have stable energetic backbone conformation with a common blue print of folding process. Molecular docking studies revealed that avirulent mutants formed more favorable hydrogen bonding with the side-chain of amino acids near to conserved NAD-binding core, despite of restraining NAD-binding specificity. Thus, structural constraints in the avirulent toxins would determine their immunogenic nature for the prioritization of protein-based subunit vaccine/immunogens to avian and veterinary animals infected with C. botulinum. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of culture filtrate proteins Rv1197 and Rv1198 of ESAT-6 family from Mycobacterium tuberculosis H37Rv.

PubMed

Pandey, Himanshu; Tripathi, Sarita; Srivastava, Kanchan; Tripathi, Dinesh K; Srivastava, Mrigank; Kant, Surya; Srivastava, Kishore K; Arora, Ashish

2017-02-01

We have characterized two immunogenic proteins, Rv1197 and Rv1198, of the Esx-5 system of the ESAT-6 family of Mycobacterium tuberculosis H37Rv. The complex formation between Rv1197 and Rv1198 was characterized by biophysical techniques. The reactivity of serum from TB patients towards these proteins was characterized by ELISA. Lymphocyte proliferation and cytokine induction were followed in restimulated splenocytes from immunized mice by using MTT assay and CBA flowcytometry, respectively. Rv1197 and Rv1198 strongly interact to form a heterodimeric complex under reducing conditions, which is characterized by a dissociation constant of 97×10 -9 M and melting temperature, Tm, of 50.5°C. Strong humoral responses to Rv1197, Rv1198, CFP-10 and MoaC1 (Rv3111) antigens were found in Indian patients with active pulmonary tuberculosis (n=44), in comparison to non-infected healthy individuals (n=20). The seroreactivity to Rv1198 was characterized by a sensitivity of 75% and specificity of 90%. In BALB/c mice, immunization with Rv1198-FIA induced a pro-inflammatory response with elevated levels of TNF and IL-6, along with low induction of IFN-γ, IL-2 and IL-10, but no induction of IL-4. Rv1197 and Rv1198 form a stable complex, which is regulated by the redox state of Rv1198. Rv1198 is immunogenic with highly specific seroreactivity towards TB patients' serum. Rv1198 elicits a pro-inflammatory recall response in immunized mice. This study characterizes the interaction of Rv1197 and Rv1198, and establishes the immunogenic nature of Rv1198. Copyright © 2016 Elsevier B.V. All rights reserved.

Immunogenicity of a plant-derived edible chimeric EspA, Intimin and Tir of Escherichia coli O157:H7 in mice.

PubMed

Amani, Jafar; Mousavi, Seyed Latif; Rafati, Sima; Salmanian, Ali Hatef

2011-04-01

Transgenic plants offer the possibility to produce and deliver an oral immunogen on a large-scale with low production costs and minimal purification or enrichment. Cattles are important reservoirs of Escherichia coli O157:H7 and developing a specific immunity in animals would be invaluable. Intimin, Tir, and EspA proteins are the virulence factors expressed by LEE locus of enterohemorrhagic E. coli. We hypothesized that the chimeric recombinant forms of these effectors delivered as an edible-base vaccine would reduce colonization of bacteria in mice. A synthetic gene (eit) composed of espA (e), eae (i) and tir (t) attached by linkers was constructed. The gene was codon optimized and cloned into plant expression vectors adjacent to CaMV35S and FAE promoters for expression in tobacco and canola plants. Of total soluble protein 0.2% and 0.3% (in average) were detected in transgenic tobacco leaves and canola seeds respectively. Mice immunized either subcutaneously or orally with recombinant EIT and challenged with E. coli O157:H7 significantly exhibited reduced bacterial shedding. Application of transgenic plants containing trivalent immunogen is an effective tool for protection against E. coli O157:H7. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Protective efficacy of cationic-PLGA microspheres loaded with DNA vaccine encoding the sip gene of Streptococcus agalactiae in tilapia.

PubMed

Ma, Yan-Ping; Ke, Hao; Liang, Zhi-Ling; Ma, Jiang-Yao; Hao, Le; Liu, Zhen-Xing

2017-07-01

Streptococcus agalactiae (S. agalactiae) is an important fish pathogen, which has received more attention in the past decade due to the increasing economic losses in the tilapia industry worldwide. As existing effective vaccines of S. agalactiae in fish have obvious disadvantage, to select immunoprotective antigens and package materials would undoubtedly contribute to the development of novel oral vaccines. In the present study, surface immunogenic protein (sip) was selected from the S. agalactiae serovar I a genomes as immunogenic protein in DNA vaccine form with cationic chitosan and biodegradable and biocompatible PLGA. The pcSip plasmid in cationic-PLGA was successfully expressed in tissues of immunized tilapia and the immunogenicity was assessed in tilapia challenge model. A significant increase was observed in the cytokine levels of IL-1β, TNF-α, CC1, CC2 in spleen and kidney tissues. Furthermore, immunized tilapia conferred different levels of protection against challenge with a lethal dose of highly virulent serovar I a S. agalactiae. Our results indicated that the pcSip plasmid in cationic-PLGA induced high level of antibodies and protection against S. agalactiae infection, could be effective oral DNA vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dietary Immunogen® modulated digestive enzyme activity and immune gene expression in Litopenaeus vannamei post larvae.

PubMed

Miandare, Hamed Kolangi; Mirghaed, Ali Taheri; Hosseini, Marjan; Mazloumi, Nastaran; Zargar, Ashkan; Nazari, Sajad

2017-11-01

Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is an important economical shrimp species worldwide, especially in the Middle East region, and farming activities of this species have been largely affected by diseases, mostly viral and bacterial diseases. Scientists have started to use prebiotics for bolstering the immune status of the animal. This study aimed to investigate the influence of Immunogen ® on growth, digestive enzyme activity and immune related gene expression of Litopenaeus vannamei post-larvae. All post-larvae were acclimated to the laboratory condition for 14 days. Upon acclimation, shrimps were fed on different levels of Immunogen ® (0, 0.5, 1 and 1.5 g kg -1 ) for 60 days. No significant differences were detected in weight gain, specific growth rate (SGR) and food conversion ratio (FCR) in shrimp post-larvae in which fed with different levels of Immunogen ® and control diet. The results showed that digestive enzymes activity including protease and lipase increased with different amounts of Immunogen ® in the shrimp diet. Protease activity increased with 1.5 g kg -1 Immunogen ® after 60 days and lipase activity increased with 1 and 1.5 g kg -1 Immunogen ® after 30 and 60 days of the trial respectively (P < 0.05), while amylase activity did not change in response to different levels of Immunogen ® (P > 0.05). The expression of immune related genes including, prophenoloxidase, crustin and g-type lysozyme increased with diet 1.5 g kg -1 Immunogen ® (P < 0.05) while expression of penaeidin gene increased only with experimental diet 1 g kg -1 of Immunogen ® . These results indicated that increase in digestive enzymes activity and expression of immune related genes could modulate the Immunogen ® in the innate immune system in L. vannamei in this study. Copyright © 2017. Published by Elsevier Ltd.

Key points in evaluating immunogenicity of pandemic influenza vaccines: A lesson from immunogenicity studies of influenza A(H1N1)pdm09 vaccine.

PubMed

Ohfuji, Satoko; Kobayashi, Masayuki; Ide, Yuichiro; Egawa, Yumi; Saito, Tomoko; Kondo, Kyoko; Ito, Kazuya; Kase, Tetsuo; Maeda, Akiko; Fukushima, Wakaba; Hirota, Yoshio

2017-09-18

Immunogenicity studies on pandemic influenza vaccine are necessary to inform rapid development and implementation of a vaccine during a pandemic. Thus, strategies for immunogenicity assessment are required. To identify essential factors to consider when evaluating the immunogenicity of pandemic influenza vaccines using the experience in Japan with the influenza A(H1N1)pdm09 vaccine. We conducted a search of observational studies using PubMed and IchushiWeb. Search terms included "influenza vaccine AND (immunogenicity OR immune response) AND Japan AND (2009 OR pdm09) NOT review," and was limited to studies conducted in humans. A total of 33 articles were identified, of which 16 articles met the inclusion criteria. Immunogenicity of the commercially available influenza A(H1N1)pdm09 vaccine satisfied the international criteria for influenza vaccine immunogenicity in all study populations. The most remarkable immune response was observed in junior high school students, while the lowest immune response was observed in hematological malignancy patients. Similar to immunogenicity studies on seasonal influenza vaccines, factors such as patient background (e.g., age, underlying condition, pre-vaccination titer, body mass index, etc.) and study procedure (e.g., concurrent measurement of pre- and post-vaccination antibody titer, effects of infection during the study period) may have affected the assessment of immunogenicity to the influenza A(H1N1)pdm09 vaccine. In addition, prior vaccination with the seasonal influenza vaccine may inhibit antibody induction by the influenza A(H1N1)pdm09 vaccine. This review discusses factors and strategies that must be considered and addressed during immunogenicity assessments of pandemic influenza vaccines, which may provide useful information for future influenza pandemics. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Allergenicity, immunogenicity and dose-relationship of three intact allergen vaccines and four allergoid vaccines for subcutaneous grass pollen immunotherapy

PubMed Central

Henmar, H; Lund, G; Lund, L; Petersen, A; Würtzen, P A

2008-01-01

Different vaccines containing intact allergens or chemically modified allergoids as active ingredients are commercially available for specific immunotherapy. Allergoids are claimed to have decreased allergenicity without loss of immunogenicity and this is stated to allow administration of high allergoid doses. We compared the allergenicity and immunogenicity of four commercially available chemically modified grass pollen allergoid products with three commercially available intact grass pollen allergen vaccines. The allergenicity was investigated with immunoglobulin (Ig)E-inhibition and basophil activation assays. Human T cell proliferation and specific IgG-titres following mouse immunizations were used to address immunogenicity. Furthermore, intact allergen vaccines with different contents of active ingredients were selected to study the influence of the allergen dose. In general, a lower allergenicity for allergen vaccines was clearly linked to a reduced immunogenicity. Compared with the vaccine with the highest amount of intact allergen, the allergoids caused reduced basophil activation as well as diminished immunogenicity demonstrated by reduced T cell activation and/or reduced induction of murine grass-specific IgG antibodies. Interestingly, intact allergen vaccines with lower content of active ingredient exhibited similarly reduced allergenicity, while immunogenicity was still higher or equal to that of allergoids. The low allergenicity observed for some allergoids was inherently linked to a significantly lower immunogenic response questioning the rationale behind the chemical modification into allergoids. In addition, the linkage between allergenicity, immunogenicity and dose found for intact allergen vaccines and the immunogen as well as allergenic immune responses observed for allergoids suggest that the modified allergen vaccines do not contain high doses of immunologically active ingredients. PMID:18647321

Intranasal delivery of Norwalk virus-like particles formulated in an in-situ gelling, dry powder vaccine

PubMed Central

Velasquez, Lissette S.; Shira, Samantha; Berta, Alice N.; Kilbourne, Jacquelyn; Medi, Babu M.; Tizard, Ian; Ni, Yawei; Arntzen, Charles J.; Herbst-Kralovetz, Melissa M.

2011-01-01

The development of a vaccine to prevent norovirus infections has been focused on immunization at a mucosal surface, but has been limited by the low immunogenicity of self-assembling Norwalk virus-like particles (NV VLPs) delivered enterically or at nasal surfaces. Nasal immunization, which offers the advantage of ease of immunization, faces obstacles imposed by the normal process of mucociliary clearance, which limits residence time of applied antigens. Herein, we describe the use of a dry powder formulation (GelVac) of an inert in-situ gelling polysaccharide (GelSite) extracted from Aloe vera for nasal delivery of NV VLP antigen. Powder formulations, with or without NV VLP antigen, were similar in structure in dry form or when rehydrated in simulated nasal fluids. Immunogenicity of the dry powder VLP formulation was compared to equivalent antigen/adjuvant liquid formulations in animals. For the GelVac powder, we observed superior NV-specific serum and mucosal (aerodigestive and reproductive tracts) antibody responses relative to liquid formulations. Incorporation of TLR7 agonist gardiquimod in dry powder formulations did not enhance antibody responses, although its inclusion in liquid formulations did enhance VLP immunogenicity irrespective of the presence or absence of GelSite. We interpret these data as showing that GelSite-based dry powder formulations 1.) stabilize the immunogenic structural properties of VLPs and 2.) induce systemic and mucosal antibody titers which are equal or greater than those achieved by VLPs plus adjuvant in a liquid formulation. We conclude that in-situ gelation of the GelVac dry powder formulation at nasal mucosal surfaces delays mucociliary clearance and thereby prolongs VLP antigen exposure to immune effector sites. PMID:21640778

Safety and Immunogenicity of PENNVAX-G DNA Prime Administered by Biojector 2000 or CELLECTRA Electroporation Device With Modified Vaccinia Ankara-CMDR Boost.

PubMed

Ake, Julie A; Schuetz, Alexandra; Pegu, Poonam; Wieczorek, Lindsay; Eller, Michael A; Kibuuka, Hannah; Sawe, Fredrick; Maboko, Leonard; Polonis, Victoria; Karasavva, Nicos; Weiner, David; Sekiziyivu, Arthur; Kosgei, Josphat; Missanga, Marco; Kroidl, Arne; Mann, Philipp; Ratto-Kim, Silvia; Anne Eller, Leigh; Earl, Patricia; Moss, Bernard; Dorsey-Spitz, Julie; Milazzo, Mark; Laissa Ouedraogo, G; Rizvi, Farrukh; Yan, Jian; Khan, Amir S; Peel, Sheila; Sardesai, Niranjan Y; Michael, Nelson L; Ngauy, Viseth; Marovich, Mary; Robb, Merlin L

2017-11-27

We report the first-in-human safety and immunogenicity evaluation of PENNVAX-G DNA/modified vaccinia Ankara-Chiang Mai double recombinant (MVA-CMDR) prime-boost human immuonodeficiency virus (HIV) vaccine, with intramuscular DNA delivery by either Biojector 2000 needle-free injection system (Biojector) or CELLECTRA electroporation device. Healthy, HIV-uninfected adults were randomized to receive 4 mg of PENNVAX-G DNA delivered intramuscularly by Biojector or electroporation at baseline and week 4 followed by intramuscular injection of 108 plaque forming units of MVA-CMDR at weeks 12 and 24. The open-label part A was conducted in the United States, followed by a double-blind, placebo-controlled part B in East Africa. Solicited and unsolicited adverse events were recorded, and immune responses were measured. Eighty-eight of 100 enrolled participants completed all study injections, which were generally safe and well tolerated, with more immediate, but transient, pain in the electroporation group. Cellular responses were observed in 57% of vaccine recipients tested and were CD4 predominant. High rates of binding antibody responses to CRF01_AE antigens, including gp70 V1V2 scaffold, were observed. Neutralizing antibodies were detected in a peripheral blood mononuclear cell assay, and moderate antibody-dependent, cell-mediated cytotoxicity activity was demonstrated. The PVG/MVA-CMDR HIV-1 vaccine regimen is safe and immunogenic. Substantial differences in safety or immunogenicity between modes of DNA delivery were not observed. NCT01260727. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

A novel, live-attenuated vesicular stomatitis virus vector displaying conformationally intact, functional HIV-1 envelope trimers that elicits potent cellular and humoral responses in mice.

PubMed

Rabinovich, Svetlana; Powell, Rebecca L R; Lindsay, Ross W B; Yuan, Maoli; Carpov, Alexei; Wilson, Aaron; Lopez, Mary; Coleman, John W; Wagner, Denise; Sharma, Palka; Kemelman, Marina; Wright, Kevin J; Seabrook, John P; Arendt, Heather; Martinez, Jennifer; DeStefano, Joanne; Chiuchiolo, Maria J; Parks, Christopher L

2014-01-01

Though vaccination with live-attenuated SIV provides the greatest protection from progressive disease caused by SIV challenge in rhesus macaques, attenuated HIV presents safety concerns as a vaccine; therefore, live viral vectors carrying HIV immunogens must be considered. We have designed a replication-competent vesicular stomatitis virus (VSV) displaying immunogenic HIV-1 Env trimers and attenuating quantities of the native surface glycoprotein (G). The clade B Env immunogen is an Env-VSV G hybrid (EnvG) in which the transmembrane and cytoplasmic tail regions are derived from G. Relocation of the G gene to the 5'terminus of the genome and insertion of EnvG into the natural G position induced a ∼1 log reduction in surface G, significant growth attenuation compared to wild-type, and incorporation of abundant EnvG. Western blot analysis indicated that ∼75% of incorporated EnvG was a mature proteolytically processed form. Flow cytometry showed that surface EnvG bound various conformationally- and trimer-specific antibodies (Abs), and in-vitro growth assays on CD4+CCR5+ cells demonstrated EnvG functionality. Neither intranasal (IN) or intramuscular (IM) administration in mice induced any observable pathology and all regimens tested generated potent Env-specific ELISA titers of 10(4)-10(5), with an IM VSV prime/IN VSV boost regimen eliciting the highest binding and neutralizing Ab titers. Significant quantities of Env-specific CD4+ T cells were also detected, which were augmented as much as 70-fold by priming with IM electroporated plasmids encoding EnvG and IL-12. These data suggest that our novel vector can achieve balanced safety and immunogenicity and should be considered as an HIV vaccine platform.

RIG-I-like helicases induce immunogenic cell death of pancreatic cancer cells and sensitize tumors toward killing by CD8+ T cells

PubMed Central

Duewell, P; Steger, A; Lohr, H; Bourhis, H; Hoelz, H; Kirchleitner, S V; Stieg, M R; Grassmann, S; Kobold, S; Siveke, J T; Endres, S; Schnurr, M

2014-01-01

Pancreatic cancer is characterized by a microenvironment suppressing immune responses. RIG-I-like helicases (RLH) are immunoreceptors for viral RNA that induce an antiviral response program via the production of type I interferons (IFN) and apoptosis in susceptible cells. We recently identified RLH as therapeutic targets of pancreatic cancer for counteracting immunosuppressive mechanisms and apoptosis induction. Here, we investigated immunogenic consequences of RLH-induced tumor cell death. Treatment of murine pancreatic cancer cell lines with RLH ligands induced production of type I IFN and proinflammatory cytokines. In addition, tumor cells died via intrinsic apoptosis and displayed features of immunogenic cell death, such as release of HMGB1 and translocation of calreticulin to the outer cell membrane. RLH-activated tumor cells led to activation of dendritic cells (DCs), which was mediated by tumor-derived type I IFN, whereas TLR, RAGE or inflammasome signaling was dispensable. Importantly, CD8α+ DCs effectively engulfed apoptotic tumor material and cross-presented tumor-associated antigen to naive CD8+ T cells. In comparison, tumor cell death mediated by oxaliplatin, staurosporine or mechanical disruption failed to induce DC activation and antigen presentation. Tumor cells treated with sublethal doses of RLH ligands upregulated Fas and MHC-I expression and were effectively sensitized towards Fas-mediated apoptosis and cytotoxic T lymphocyte (CTL)-mediated lysis. Vaccination of mice with RLH-activated tumor cells induced protective antitumor immunity in vivo. In addition, MDA5-based immunotherapy led to effective tumor control of established pancreatic tumors. In summary, RLH ligands induce a highly immunogenic form of tumor cell death linking innate and adaptive immunity. PMID:25012502

Dendritic Cell Targeting of Bacillus anthracis Protective Antigen Expressed by Lactobacillus acidophilus Protects Mice from Lethal Challenge

DTIC Science & Technology

2008-10-28

highly immunogenic, which may prevent their use in vaccine regimens requiring multiple doses (4). Probiotics are defined as ‘‘live microorganisms that...Sterne lethal challenge (Fig. 3 B and C). Thus, results from these studies further highlight the efficacy of employing probiotic lactic acid bacteria in...delivery via probiotic lactic acid bacteria is in their ability to induce antigen-specific IgA responses in feces, saliva, bronchoalveolar, mesenteric

Unlocking Barriers to DNA Vaccine Immunogenicity: A Cross-Species Analysis of Cytosolic DNA Sensing in Skeletal Muscle Myocytes

DTIC Science & Technology

2017-10-01

CRISPR Subtask 1A: i) design and produce mammalian expression plasmids encoding the Cas9 protein and specially...duration in SOW: 2017 Q4 – 2018 Q1 Subtask 2A: i) produce mouse myocyte cell lines that have undergone gene disruption via a technique named CRISPR ii...named CRISPR ii) confirm gene disruption and GFP expression iii) select multiple individual clones characterized with quantitative gene

Cellular immune responses against CT7 (MAGE-C1) and humoral responses against other cancer-testis antigens in multiple myeloma patients

PubMed Central

Lendvai, Nikoletta; Gnjatic, Sacha; Ritter, Erika; Mangone, Michael; Austin, Wayne; Reyner, Karina; Jayabalan, David; Niesvizky, Ruben; Jagannath, Sundar; Bhardwaj, Nina; Chen-Kiang, Selina; Old, Lloyd J.

2010-01-01

The type I melanoma antigen gene (MAGE) proteins CT7 (MAGE-C1) and MAGE-A3 are commonly expressed in multiple myeloma (MM), and their expression correlates with increased plasma cell proliferation and poor clinical outcome. They belong to the cancer-testis antigen (CTAg) group of tumor-associated proteins, some of which elicit spontaneous immune responses in cancer patients. CT7 and MAGE-A3 are promising antigenic targets for therapeutic tumor vaccines in myeloma; therefore, it is critical to determine if they are immunogenic in MM patients. We analyzed cellular and humoral immune responses against CTAgs in patients with plasma cell dyscrasias: MM, monoclonal gammopathy of undetermined significance (MGUS), and Waldenström's macroglobulinemia (WM). Bone marrow lymphocytes from two of four untreated MM patients exhibited CT7-specific cellular immune responses as measured by an autologous cellular immunity assay, the first such immune response to CT7 to be reported in cancer patients. Sera from 24 patients were screened by ELISA for humoral immune responses to CTAgs. Two patients with MM demonstrated positive titers, one for MAGE-A1 and the other for SSX1. These data demonstrate that CTAgs, particularly CT7, are immunogenic in MM patients and merit further exploration as targets of immunological therapy in MM. PMID:20108890

Cellular immune responses against CT7 (MAGE-C1) and humoral responses against other cancer-testis antigens in multiple myeloma patients.

PubMed

Lendvai, Nikoletta; Gnjatic, Sacha; Ritter, Erika; Mangone, Michael; Austin, Wayne; Reyner, Karina; Jayabalan, David; Niesvizky, Ruben; Jagannath, Sundar; Bhardwaj, Nina; Chen-Kiang, Selina; Old, Lloyd J; Cho, Hearn Jay

2010-01-29

The type I melanoma antigen gene (MAGE) proteins CT7 (MAGE-C1) and MAGE-A3 are commonly expressed in multiple myeloma (MM), and their expression correlates with increased plasma cell proliferation and poor clinical outcome. They belong to the cancer-testis antigen (CTAg) group of tumor-associated proteins, some of which elicit spontaneous immune responses in cancer patients. CT7 and MAGE-A3 are promising antigenic targets for therapeutic tumor vaccines in myeloma; therefore, it is critical to determine if they are immunogenic in MM patients. We analyzed cellular and humoral immune responses against CTAgs in patients with plasma cell dyscrasias: MM, monoclonal gammopathy of undetermined significance (MGUS), and Waldenström's macroglobulinemia (WM). Bone marrow lymphocytes from two of four untreated MM patients exhibited CT7-specific cellular immune responses as measured by an autologous cellular immunity assay, the first such immune response to CT7 to be reported in cancer patients. Sera from 24 patients were screened by ELISA for humoral immune responses to CTAgs. Two patients with MM demonstrated positive titers, one for MAGE-A1 and the other for SSX1. These data demonstrate that CTAgs, particularly CT7, are immunogenic in MM patients and merit further exploration as targets of immunological therapy in MM.

T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.

PubMed

de Melo, Andréa Barbosa; Nascimento, Eduardo J M; Braga-Neto, Ulisses; Dhalia, Rafael; Silva, Ana Maria; Oelke, Mathias; Schneck, Jonathan P; Sidney, John; Sette, Alessandro; Montenegro, Silvia M L; Marques, Ernesto T A

2013-01-01

The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4(+) and CD8(+) T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines.

Safety and immunogenicity of ricin vaccine, RVEc™, in a Phase 1 clinical trial.

PubMed

Pittman, Phillip R; Reisler, Ronald B; Lindsey, Changhong Y; Güereña, Fernando; Rivard, Robert; Clizbe, Denise P; Chambers, Matthew; Norris, Sarah; Smith, Leonard A

2015-12-16

Ricin is a potent toxin and potential bioterrorism weapon for which no specific licensed countermeasures are available. We report the safety and immunogenicity of the ricin vaccine RVEc™ in a Phase 1 (N=30) multiple-dose, open-label, non-placebo-controlled, dose-escalating (20, 50, and 100μg), single-center study. Each subject in the 20- and 50-μg dose groups (n=10 for each group) received three injections at 4-week intervals and was observed carefully for untoward effects of the vaccine; blood was drawn at predetermined intervals after each dose for up to 1 year. RVEc™ was safe and well tolerated at the 20- and 50-μg doses. The most common adverse events were pain at the injection site and headache. Of the 10 subjects who received a single 100-μg dose, two developed elevated creatine phosphokinase levels, which resolved without sequelae. No additional doses were administered to subjects in the 100-μg group. Immunogenicity of the vaccine was evaluated by measuring antibody response using the well standardized enzyme-linked immunosorbent assay (ELISA) and toxin neutralization assay (TNA). Of the subjects in the 20- and 50-μg dose groups, 100% achieved ELISA anti-ricin IgG titers of 1:500 to 1:121,500 and 50% produced neutralizing anti-ricin antibodies measurable by TNA. Four subjects in the 50-μg group received a single booster dose of RVEc™ 20-21 months after the initial dose. The single booster was safe and well tolerated, resulting in no serious adverse events, and significantly enhanced immunogenicity of the vaccine in human subjects. Each booster recipient developed a robust anamnestic response with ELISA anti-ricin IgG titers of 1:13,500 to 1:121,500 and neutralizing antibody titers of 1:400 to 1:3200. Future studies will attempt to optimize dose, scheduling, and route of administration. This study is registered at clinicaltrials.gov (NCT01317667 and NCT01846104). Published by Elsevier Ltd.

Safety, immunogenicity and efficacy of a recombinant tetravalent dengue vaccine: a meta-analysis of randomized trials.

PubMed

da Costa, Vivaldo G; Marques-Silva, Ariany C; Floriano, Vitor G; Moreli, Marcos L

2014-09-03

The World Health Organization has stipulated a target: reduce the mortality rate caused by dengue disease by 50% until 2020. Most likely, this goal can be achieved by means of a dengue vaccine. Accordingly, the recombinant and tetravalent dengue vaccine (CYD-TDV), developed by the Sanofi Pasteur Group, is in an advanced stage of human testing. Although there are multiple randomized, placebo-controlled trials evaluating the CYD-TDV, individual results may have little power to identify differences between the populations studied. Thus, we conducted a meta-analysis to determine a more precise estimate of the overall parameters of safety, immunogenicity and efficacy of CYD-TDV. A data search was conducted in the PubMed, Medline, Cochrane Central Register of Controlled Trials and SciELO databases with defined selection criteria. We included for meta-analysis seven randomized and placebo-controlled studies that included 6678 patients randomized to receive the CYD-TDV (4586) or placebo (2092). Regarding vaccine safety, it was found that there was no significant difference between treated and placebo groups, as only approximately 5.5% of patients were withdrawn from the study. Regarding immunogenicity, the levels of neutralizing antibodies were measured by weighted mean differences (WMD), which were always higher in the vaccinated group (WMD/DENV1=59.7, 95% confidence interval [CI] 57-61; WMD/DENV2=99, 95% CI 95-102; WMD/DENV3=138, 95% CI 133-142; WMD/DENV4=123, 95% CI 119-126). The clinical efficacy of the vaccine was 59% (95% CI 15-80; RR=0.41, 95% CI 0.2-0.85, I(2)=30.9%). In conclusion, safety and a balanced immune response to the CYD-TDV were found. However, to fully establish the clinical effectiveness and robustness of immunogenicity, it is necessary to perform further studies to assess the long-term effects of the vaccine. Copyright © 2014 Elsevier Ltd. All rights reserved.

T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

PubMed Central

de Melo, Andréa Barbosa; Nascimento, Eduardo J. M.; Braga-Neto, Ulisses; Dhalia, Rafael; Silva, Ana Maria; Oelke, Mathias; Schneck, Jonathan P.; Sidney, John; Sette, Alessandro; Montenegro, Silvia M. L.; Marques, Ernesto T. A.

2013-01-01

The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, “promiscuous” T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. PMID:23383350

Identification and characterization of major cat allergen Fel d 1 mimotopes on filamentous phage carriers.

PubMed

Luzar, Jernej; Molek, Peter; Šilar, Mira; Korošec, Peter; Košnik, Mitja; Štrukelj, Borut; Lunder, Mojca

2016-03-01

Cat allergy is one of the most prevalent allergies worldwide and can lead to the development of rhinitis and asthma. Thus far, only allergen extracts from natural sources have been used for allergen-specific immunotherapy. However, extracts and whole allergens in immunotherapy present an anaphylaxis risk. Identification of allergen epitopes or mimotopes has an important role in development of safe and effective allergen-specific immunotherapy. Moreover, with a suitable immunogenic carrier, the absence of sufficient immune response elicited by short peptides could be surmounted. In this study, we identified five structural mimotopes of the major cat allergen Fel d 1 by immunoscreening with random peptide phage libraries. The mimotopes were computationally mapped to the allergen surface, and their IgE reactivity was confirmed using sera from cat-allergic patients. Importantly, the mimotopes showed no basophil activation of the corresponding cat-allergic patients, which makes them good candidates for the development of hypoallergenic vaccine. As bacteriophage particles are becoming increasingly recognized as immunogenic carriers, we constructed bacteriophage particles displaying multiple copies of each selected mimotope on major phage coat protein. These constructed phages elicited T cell-mediated immune response, which was predominated by the type 1 T cell response. Mimotopes alone contributed to the type 1 T cell response by promoting IL-2 production. Fel d 1 mimotopes, as well as their filamentous phage immunogenic carriers, represent promising candidates in the development of hypoallergenic vaccine against cat allergy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cryopreservation-related loss of antigen-specific IFNγ producing CD4+ T-cells can skew immunogenicity data in vaccine trials: Lessons from a malaria vaccine trial substudy.

PubMed

Ford, Tom; Wenden, Claire; Mbekeani, Alison; Dally, Len; Cox, Josephine H; Morin, Merribeth; Winstone, Nicola; Hill, Adrian V S; Gilmour, Jill; Ewer, Katie J

2017-04-04

Ex vivo functional immunoassays such as ELISpot and intracellular cytokine staining (ICS) by flow cytometry are crucial tools in vaccine development both in the identification of novel immunogenic targets and in the immunological assessment of samples from clinical trials. Cryopreservation and subsequent thawing of PBMCs via validated processes has become a mainstay of clinical trials due to processing restrictions inherent in the disparate location and capacity of trial centres, and also in the need to standardize biological assays at central testing facilities. Logistical and financial requirement to batch process samples from multiple study timepoints are also key. We used ELISpot and ICS assays to assess antigen-specific immunogenicity in blood samples taken from subjects enrolled in a phase II malaria heterologous prime-boost vaccine trial and showed that the freeze thaw process can result in a 3-5-fold reduction of malaria antigen-specific IFNγ-producing CD3 + CD4 + effector populations from PBMC samples taken post vaccination. We have also demonstrated that peptide responsive CD8 + T cells are relatively unaffected, as well as CD4 + T cell populations that do not produce IFNγ. These findings contribute to a growing body of data that could be consolidated and synthesised as guidelines for clinical trials with the aim of increasing the efficiency of vaccine development pipelines. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A HIV-Tat/C4-binding protein chimera encoded by a DNA vaccine is highly immunogenic and contains acute EcoHIV infection in mice.

PubMed

Tomusange, Khamis; Wijesundara, Danushka; Gummow, Jason; Garrod, Tamsin; Li, Yanrui; Gray, Lachlan; Churchill, Melissa; Grubor-Bauk, Branka; Gowans, Eric J

2016-06-30

DNA vaccines are cost-effective to manufacture on a global scale and Tat-based DNA vaccines have yielded protective outcomes in preclinical and clinical models of human immunodeficiency virus (HIV), highlighting the potential of such vaccines. However, Tat-based DNA vaccines have been poorly immunogenic, and despite the administration of multiple doses and/or the addition of adjuvants, these vaccines are not in general use. In this study, we improved Tat immunogenicity by fusing it with the oligomerisation domain of a chimeric C4-binding protein (C4b-p), termed IMX313, resulting in Tat heptamerisation and linked Tat to the leader sequence of tissue plasminogen activator (TPA) to ensure that the bulk of heptamerised Tat is secreted. Mice vaccinated with secreted Tat fused to IMX313 (pVAX-sTat-IMX313) developed higher titres of Tat-specific serum IgG, mucosal sIgA and cell-mediated immune (CMI) responses, and showed superior control of EcoHIV infection, a surrogate murine HIV challenge model, compared with animals vaccinated with other test vaccines. Given the crucial contribution of Tat to HIV-1 pathogenesis and the precedent of Tat-based DNA vaccines in conferring some level of protection in animal models, we believe that the virologic control demonstrated with this novel multimerised Tat vaccine highlights the promise of this vaccine candidate for humans.

Identification of Immunogenic Targets for Lung Cancer Vaccines

DTIC Science & Technology

2017-09-01

quantitative proteomic analysis to identify proteins overexpressed in non-small cell lung cancer cell lines compared with normal lung epithelial...Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT: Approved for Public Release; Distribution...Department of the Army position, policy or decision unless so designated by other documentation. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188

Take my breath away: necrosis in kidney transplants kills the lungs!

PubMed

Vanden Berghe, Tom; Linkermann, Andreas

2015-04-01

Necrosis is not only a regulated process, it is an interconnected molecular network allowing different genetically encoded forms that are more or less immunogenic. Zhao et al. elegantly illustrate this concept, underscore the need for combination therapy to successfully interfere with regulated necrosis, and identify the role of regulated necrosis in the pathophysiology of remote lung injury.

Comparable Antigenicity and Immunogenicity of Oligomeric Forms of a Novel, Acute HIV-1 Subtype C gp145 Envelope for Use in Preclinical and Clinical Vaccine Research.

PubMed

Wieczorek, Lindsay; Krebs, Shelly J; Kalyanaraman, Vaniambadi; Whitney, Stephen; Tovanabutra, Sodsai; Moscoso, Carlos G; Sanders-Buell, Eric; Williams, Constance; Slike, Bonnie; Molnar, Sebastian; Dussupt, Vincent; Alam, S Munir; Chenine, Agnes-Laurence; Tong, Tina; Hill, Edgar L; Liao, Hua-Xin; Hoelscher, Michael; Maboko, Leonard; Zolla-Pazner, Susan; Haynes, Barton F; Pensiero, Michael; McCutchan, Francine; Malek-Salehi, Shawyon; Cheng, R Holland; Robb, Merlin L; VanCott, Thomas; Michael, Nelson L; Marovich, Mary A; Alving, Carl R; Matyas, Gary R; Rao, Mangala; Polonis, Victoria R

2015-08-01

Eliciting broadly reactive functional antibodies remains a challenge in human immunodeficiency virus type 1 (HIV-1) vaccine development that is complicated by variations in envelope (Env) subtype and structure. The majority of new global HIV-1 infections are subtype C, and novel antigenic properties have been described for subtype C Env proteins. Thus, an HIV-1 subtype C Env protein (CO6980v0c22) from an infected person in the acute phase (Fiebig stage I/II) was developed as a research reagent and candidate immunogen. The gp145 envelope is a novel immunogen with a fully intact membrane-proximal external region (MPER), extended by a polylysine tail. Soluble gp145 was enriched for trimers that yielded the expected "fan blade" motifs when visualized by cryoelectron microscopy. CO6980v0c22 gp145 reacts with the 4E10, PG9, PG16, and VRC01 HIV-1 neutralizing monoclonal antibodies (MAbs), as well as the V1/V2-specific PGT121, 697, 2158, and 2297 MAbs. Different gp145 oligomers were tested for immunogenicity in rabbits, and purified dimers, trimers, and larger multimers elicited similar levels of cross-subtype binding and neutralizing antibodies to tier 1 and some tier 2 viruses. Immunized rabbit sera did not neutralize the highly resistant CO6980v0c22 pseudovirus but did inhibit the homologous infectious molecular clone in a peripheral blood mononuclear cell (PBMC) assay. This Env is currently in good manufacturing practice (GMP) production to be made available for use as a clinical research tool and further evaluation as a candidate vaccine. At present, the product pipeline for HIV vaccines is insufficient and is limited by inadequate capacity to produce large quantities of vaccine to standards required for human clinical trials. Such products are required to evaluate critical questions of vaccine formulation, route, dosing, and schedule, as well as to establish vaccine efficacy. The gp145 Env protein presented in this study forms physical trimers, binds to many of the well-characterized broad neutralizing MAbs that target conserved Env epitopes, and induce cross-subtype neutralizing antibodies as measured in both cell line and primary cell assays. This subtype C Env gp145 protein is currently undergoing good manufacturing practice production for use as a reagent for preclinical studies and for human clinical research. This product will serve as a reagent for comparative studies and may represent a next-generation candidate HIV immunogen. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Attenuated Human Parainfluenza Virus Type 1 Expressing Ebola Virus Glycoprotein GP Administered Intranasally Is Immunogenic in African Green Monkeys.

PubMed

Lingemann, Matthias; Liu, Xueqiao; Surman, Sonja; Liang, Bo; Herbert, Richard; Hackenberg, Ashley D; Buchholz, Ursula J; Collins, Peter L; Munir, Shirin

2017-05-15

The recent 2014-2016 Ebola virus (EBOV) outbreak prompted increased efforts to develop vaccines against EBOV disease. We describe the development and preclinical evaluation of an attenuated recombinant human parainfluenza virus type 1 (rHPIV1) expressing the membrane-anchored form of EBOV glycoprotein GP, as an intranasal (i.n.) EBOV vaccine. GP was codon optimized and expressed either as a full-length protein or as an engineered chimeric form in which its transmembrane and cytoplasmic tail (TMCT) domains were replaced with those of the HPIV1 F protein in an effort to enhance packaging into the vector particle and immunogenicity. GP was inserted either preceding the N gene (pre-N) or between the N and P genes (N-P) of rHPIV1 bearing a stabilized attenuating mutation in the P/C gene (C Δ170 ). The constructs grew to high titers and efficiently and stably expressed GP. Viruses were attenuated, replicating at low titers over several days, in the respiratory tract of African green monkeys (AGMs). Two doses of candidates expressing GP from the pre-N position elicited higher GP neutralizing serum antibody titers than the N-P viruses, and unmodified GP induced higher levels than its TMCT counterpart. Unmodified EBOV GP was packaged into the HPIV1 particle, and the TMCT modification did not increase packaging or immunogenicity but rather reduced the stability of GP expression during in vivo replication. In conclusion, we identified an attenuated and immunogenic i.n. vaccine candidate expressing GP from the pre-N position. It is expected to be well tolerated in humans and is available for clinical evaluation. IMPORTANCE EBOV hemorrhagic fever is one of the most lethal viral infections and lacks a licensed vaccine. Contact of fluids from infected individuals, including droplets or aerosols, with mucosal surfaces is an important route of EBOV spread during a natural outbreak, and aerosols also might be exploited for intentional virus spread. Therefore, vaccines that protect against mucosal as well as systemic inoculation are needed. We evaluated a version of human parainfluenza virus type 1 (HPIV1) bearing a stabilized attenuating mutation in the P/C gene (C Δ170 ) as an intranasal vaccine vector to express the EBOV glycoprotein GP. We evaluated expression from two different genome positions (pre-N and N-P) and investigated the use of vector packaging signals. African green monkeys immunized with two doses of the vector expressing GP from the pre-N position developed high titers of GP neutralizing serum antibodies. The attenuated vaccine candidate is expected to be safe and immunogenic and is available for clinical development. Copyright © 2017 American Society for Microbiology.

A Streptococcus mutans immunogen that reacts equally with S. mutans antibody of all serotypes.

PubMed

Everhart, D L; Miglietta, L M; Maresca, V A; Kelly-Hatfield, P

1984-01-01

We have studied a possible immunogen from S. mutans that has the capability of producing antibody to S. mutans which reacts equally well with all serotypes. This immunogen, a ribosomal preparation, is immunogenic in mice, is antigenic with rabbit anti-S. mutans, and is antigenic with the human antibody that also reacts with S. mutans. The human antibody is of the IgG class and S-IgA class.

Safety and Immunogenicity Testing of a Pilot Polysaccharide Vaccine Preparation to Pseudomonas aeruginosa.

DTIC Science & Technology

1981-09-01

8217-NAL." BUR-._,AL)- ’..O,.-,.S.AN--DA. .-D-S.... . . . .A AD___________ Safety and Immunogenicity Testing of a Pilot Polysaccharide Vaccine Preparation...COVERED Safety and Immunogenicity Testing of a Pilot Annual Report Polysaccharide Vaccine Preparation to (16 Aug. 80 - 1 Aug. 81) Pseudomonas...immunogenic or biologically active component of the vaccine. The vaccine is a high molecu- lar weight polysaccharide (PS) material isolated from the outer

Salk's HIV immunogen: an immune-based therapy in human trials since 1988.

PubMed

Jonas Salk, the developer of the first polio vaccine, has created a therapeutic vaccine for HIV which helps the immune system fight disease progression. Salk uses inactivated HIV-1 virus combined with Incomplete Freund's Adjuvant (IFA) in the vaccine preparation. The resulting HIV-1 immunogen was first studied in 1987, and since then, 235 seropositive individuals have received inoculations without serious adverse effects. Data from the first 25 subjects indicate that immunization with the HIV-1 immunogen results in improvement of cell-mediated response against the virus, a slower increase in the amount of virus present, and a reduced rate of clinical progression. Subsequent studies also show that higher doses of immunogen may produce stronger cell-mediated responses and high HIV-DTH (delayed-type hypersensitivity responsiveness immunogen) is associated with better outcome. Additional trials of HIV-1 immunogen are awaiting Food and Drug Administration approval.

Presentation of lipid antigens to T cells.

PubMed

Mori, Lucia; De Libero, Gennaro

2008-04-15

T cells specific for lipid antigens participate in regulation of the immune response during infections, tumor immunosurveillance, allergy and autoimmune diseases. T cells recognize lipid antigens as complexes formed with CD1 antigen-presenting molecules, thus resembling recognition of MHC-peptide complexes. The biophysical properties of lipids impose unique mechanisms for their delivery, internalization into antigen-presenting cells, membrane trafficking, processing, and loading of CD1 molecules. Each of these steps is controlled at molecular and celular levels and determines lipid immunogenicity. Lipid antigens may derive from microbes and from the cellular metabolism, thus allowing the immune system to survey a large repertoire of immunogenic molecules. Recognition of lipid antigens facilitates the detection of infectious agents and the initiation of responses involved in immunoregulation and autoimmunity. This review focuses on the presentation mechanisms and specific recognition of self and bacterial lipid antigens and discusses the important open issues.

Maturation of the lymphoid system. II. Characterization of the cellular levels of unresponsiveness induced in neonates by a T-dependent antigen that is an obligate immunogen in adults.

PubMed

Etlinger, H M; Chiller, J M

1979-06-01

It has previously shown that AHGG, a form of HGG that is highly immunogenic in euthymic adult mice, is capable of inducing specific unresponsiveness when injected into neonatal animals. This report extends this finding and indicates that such a neonatal treatment results in the induction of tolerance in T as well as B cells. Furthermore, a similar conclusion was reached regarding specific T lymphocyte function in animals treated as neonates with OVA. The ability of LPS to modulate responses of neonatal animals to AHGG or DHGG was also examined. It appeared that such mice were not susceptible to the adjuvant effects of LPS until the 4th week of life. Furthermore, LPS was incapable of inhibiting the unresponsiveness induced in mice by either DHGG or AHGG until the 3rd or 4th week of life.

Elicitation of strong immune responses by a DNA vaccine expressing a secreted form of hepatitis C virus envelope protein E2 in murine and porcine animal models

PubMed Central

Li, Yi-Ping; Kang, Hye Na; Babiuk, Lorne A; Liu, Qiang

2006-01-01

AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS: Intradermal injection of E2 DNA vaccine induced strong Th1-like immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-like ones in piglets. CONCLUSION: A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations. PMID:17131474

Immunogenic peptides comprising a T-helper epitope and a B-cell neutralizing antibody epitope

DOEpatents

Haynes, Barton F [Durham, NC; Korber, Bette T [Los Alamos, NM; De Lorimier, Robert M [Durham, NC

2006-12-26

The present invention relates, generally, to a polyvalent immunogen and, more particularly, to a method of inducing neutralizing antibodies against HIV and to a polyvalent immunogen suitable for use in such a method.

The value of duck-embryo vaccine and high-egg-passage Flury vaccine in experimental rabies infection in guinea-pigs

PubMed Central

Veeraraghavan, N.; Subrahmanyan, T. P.

1963-01-01

The authors have compared the value of multiple doses of duck-embryo and HEP Flury vaccine with that of pooled 5% sheep-brain vaccine in experimental rabies infection in guinea-pigs. They found that the duck-embryo vaccine given in a dosage corresponding to 14 ml of 10% vaccine (the dosage recommended for human treatment), either alone or with antirabies serum, gave no protection and that, even when administered in a dosage corresponding to 140 ml of 5% pooled vaccine, both the duck-embryo and the HEP Flury vaccines, whether alone or with serum, conferred little protection. Pooled phenolized vaccine under identical conditions gave good results. The immunogenicity of duck-embryo and HEP Flury vaccines, given before infection, was also inferior to that of pooled vaccine; and the duck-embryo vaccine was found to be a poorer antigen than the pooled vaccine in mouse potency tests. The authors conclude that the dosage of duck-embryo vaccine recommended for human treatment is inadequate and that the HEP Flury vaccine in its present form is unsuitable for post-infection treatment. PMID:14065070

Molecular-specific urokinase antibodies

NASA Technical Reports Server (NTRS)

Atassi, M. Zouhair (Inventor); Morrison, Dennis R. (Inventor)

2009-01-01

Antibodies have been developed against the different molecular forms of urokinase using synthetic peptides as immunogens. The peptides were synthesized specifically to represent those regions of the urokinase molecules which are exposed in the three-dimensional configuration of the molecule and are uniquely homologous to urokinase. Antibodies are directed against the lysine 158-isoleucine 159 peptide bond which is cleaved during activation from the single-chain (ScuPA) form to the bioactive double chain (54 KDa and 33 KDa) forms of urokinase and against the lysine 135 lysine 136 bond that is cleaved in the process of removing the alpha-chain from the 54 KDa form to produce the 33 KDa form of urokinase. These antibodies enable the direct measurement of the different molecular forms of urokinase from small samples of conditioned medium harvested from cell cultures.

The Influences of Glycosylation on the Antigenicity, Immunogenicity, and Protective Efficacy of Ebola Virus GP DNA Vaccines

DTIC Science & Technology

2006-11-22

multiple muta- tions were not studied, (iii) a vaccinia virus (VACV)- T7 system was used for transient expression, (iv) pseudotyped retrovi- ruses were used...those studies produced little to no detectable GP1 or GP2 in the transient VACV- T7 expression assays, whereas in our studies with the DNA con- structs...type GP2 was detected in pseudotyped retroviruses, a result seemingly in conflict with these authors’ findings with the VACV- T7 expression. Although

Prolonging microtubule dysruption enhances the immunogenicity of chronic lymphocytic leukaemia cells

PubMed Central

Shaha, S P; Tomic, J; Shi, Y; Pham, T; Mero, P; White, D; He, L; Baryza, J L; Wender, P A; Booth, J W; Spaner, D E

2009-01-01

Cytotoxic chemotherapies do not usually mediate the expression of an immunogenic gene programme in tumours, despite activating many of the signalling pathways employed by highly immunogenic cells. Concomitant use of agents that modulate and complement stress-signalling pathways activated by chemotherapeutic agents may then enhance the immunogenicity of cancer cells, increase their susceptibility to T cell-mediated controls and lead to higher clinical remission rates. Consistent with this hypothesis, the microtubule inhibitor, vincristine, caused chronic lymphocytic leukaemia (CLL) cells to die rapidly, without increasing their immunogenicity. Protein kinase C (PKC) agonists (such as bryostatin) delayed the death of vincristine-treated CLL cells and made them highly immunogenic, with increased stimulatory abilities in mixed lymphocyte responses, production of proinflammatory cytokines, expression of co-stimulatory molecules and activation of c-Jun N-terminal kinase (JNK), p38 and nuclear factor kappa B (NF-κB) signalling pathways. This phenotype was similar to the result of activating CLL cells through Toll-like receptors (TLRs), which communicate ‘danger’ signals from infectious pathogens. Use of PKC agonists and microtubule inhibitors to mimic TLR-signalling, and increase the immunogenicity of CLL cells, has implications for the design of chemo-immunotherapeutic strategies. PMID:19737143

Impact of product-related factors on immunogenicity of biotherapeutics.

PubMed

Singh, Satish Kumar

2011-02-01

All protein therapeutics have the potential to be immunogenic. Several factors, including patient characteristics, disease state, and the therapy itself, influence the generation of an immune response. Product-related factors such as the molecule design, the expression system, post-translational modifications, impurities, contaminants, formulation and excipients, container, closure, as well as degradation products are all implicated. However, a critical examination of the available data shows that clear unequivocal evidence for the impact of these latter factors on clinical immunogenicity is lacking. No report could be found that clearly deconvolutes the clinical impact of the product attributes on patient susceptibility. Aggregation carries the greatest concern as a risk factor for immunogenicity, but the impact of aggregates is likely to depend on their structure as well as on the functionality (e.g., immunostimulatory or immunomodulatory) of the therapeutic. Preclinical studies are not yet capable of assessing the clinically relevant immunogenicity potential of these product-related factors. Simply addressing these risk factors as part of product development will not eliminate immunogenicity. Minimization of immunogenicity has to begin at the molecule design stage by reducing or eliminating antigenic epitopes and building in favorable physical and chemical properties. Copyright © 2010 Wiley-Liss, Inc.

Functional Analysis of the Anti-adalimumab Response Using Patient-derived Monoclonal Antibodies♦

PubMed Central

van Schouwenburg, Pauline A.; Kruithof, Simone; Votsmeier, Christian; van Schie, Karin; Hart, Margreet H.; de Jong, Rob N.; van Buren, Esther E. L.; van Ham, Marieke; Aarden, Lucien; Wolbink, Gertjan; Wouters, Diana; Rispens, Theo

2014-01-01

The production of antibodies to adalimumab in autoimmune patients treated with adalimumab is shown to diminish treatment efficacy. We previously showed that these antibodies are almost exclusively neutralizing, indicating a restricted response. Here, we investigated the characteristics of a panel of patient-derived monoclonal antibodies for binding to adalimumab. Single B-cells were isolated from two patients, cultured, and screened for adalimumab specificity. Analysis of variable region sequences of 16 clones suggests that the immune response against adalimumab is broad, involving multiple B-cell clones each using different combinations of V(D)J segments. A strong bias for replacement mutations in the complementarity determining regions was found, indicating an antigen-driven response. We recombinantly expressed 11 different monoclonal antibodies and investigated their affinity and specificity. All clones except one are of high affinity (Kd between 0.6 and 233 pm) and compete with TNF as well as each other for binding to adalimumab. However, binding to a panel of single-point mutants of adalimumab indicates markedly different fine specificities that also result in a differential tendency of each clone to form dimeric and multimeric immune complexes. We conclude that although all anti-adalimumab antibodies compete for binding to TNF, the response is clonally diverse and involves multiple epitopes on adalimumab. These results are important for understanding the relationship between self and non-self or idiotypic determinants on therapeutic antibodies and their potential immunogenicity. PMID:25326381

The increased incidence of pure red cell aplasia with an Eprex formulation in uncoated rubber stopper syringes.

PubMed

Boven, Katia; Stryker, Scott; Knight, John; Thomas, Adrian; van Regenmortel, Marc; Kemeny, David M; Power, David; Rossert, Jerome; Casadevall, Nicole

2005-06-01

The incidence of pure red cell aplasia (PRCA) in chronic kidney disease patients treated with epoetins increased substantially in 1998, was shown to be antibody mediated, and was associated predominantly with subcutaneous administration of Eprex. A technical investigation identified organic compounds leached from uncoated rubber stoppers in prefilled syringes containing polysorbate 80 as the most probable cause of the increased immunogenicity. This study investigated whether the incidence of PRCA was higher for exposure to the product form containing leachates than for leachate-free product forms. Antibody-mediated PRCA cases were classified according to indication, product form, and route of administration. Exposure estimates were obtained by country, indication, route of administration, and product form. For 2001 to 2003, the PRCA incidence rate for patients with subcutaneous exposure to Eprex in prefilled syringes with polysorbate 80 and uncoated rubber stoppers (leachates present) was 4.61/10,000 patient years (95% CI 3.88-5.43) versus 0.26/10,000 patient years (95% CI 0.007-1.44) for syringes with coated stoppers (leachates absent). The rate difference was 4.35/10,000 patient years (95% CI 3.44-5.26; P < 0.0001); the rate ratio was 17 (95% CI 3.14-707). A substantial rate difference remained in sensitivity analyses that adjusted for exposure to multiple product forms. The epidemiologic data, together with the chemical and immunologic data, support the hypothesis that leachates from uncoated rubber syringe stoppers caused the increased incidence of PRCA associated with Eprex. Currently, all Eprex prefilled syringes contain fluoro-resin coated stoppers, which has contributed to decreased incidence of PRCA with continued surveillance.

Immunogenicity of HPV prophylactic vaccines: Serology assays and their use in HPV vaccine evaluation and development.

PubMed

Pinto, Ligia A; Dillner, Joakim; Beddows, Simon; Unger, Elizabeth R

2018-01-17

When administered as standard three-dose schedules, the licensed HPV prophylactic vaccines have demonstrated extraordinary immunogenicity and efficacy. We summarize the immunogenicity of these licensed vaccines and the most commonly used serology assays, with a focus on key considerations for one-dose vaccine schedules. Although immune correlates of protection against infection are not entirely clear, both preclinical and clinical evidence point to neutralizing antibodies as the principal mechanism of protection. Thus, immunogenicity assessments in vaccine trials have focused on measurements of antibody responses to the vaccine. Non-inferiority of antibody responses after two doses of HPV vaccines separated by 6 months has been demonstrated and this evidence supported the recent WHO recommendations for two-dose vaccination schedules in both boys and girls 9-14 years of age. There is also some evidence suggesting that one dose of HPV vaccines may provide protection similar to the currently recommended two-dose regimens but robust data on efficacy and immunogenicity of one-dose vaccine schedules are lacking. In addition, immunogenicity has been assessed and reported using different methods, precluding direct comparison of results between different studies and vaccines. New head-to-head vaccine trials evaluating one-dose immunogenicity and efficacy have been initiated and an increase in the number of trials relying on immunobridging is anticipated. Therefore, standardized measurement and reporting of immunogenicity for the up to nine HPV types targeted by the current vaccines is now critical. Building on previous HPV serology assay standardization and harmonization efforts initiated by the WHO HPV LabNet in 2006, new secondary standards, critical reference reagents and testing guidelines will be generated as part of a new partnership to facilitate harmonization of the immunogenicity testing in new HPV vaccine trials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combined radiotherapy and Corynebacterium parvum treatment of rat tumors with different immunogenicity. [X rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moroson, H.; Stowe, S.; Rotman, M.

1978-01-01

Evidence is presented that combined radiotherapy and Corynebacterium parvum treatment gives better results than radiotherapy alone in rats bearing a chemically-induced highly-immunogenic transplanted fibrosarcoma termed BP 179; however, similar behavior is not observed with either of two weakly-immunogenic mammary carcinomas, 13762 or ME/H. Relative immunogenicity is determined by the ability of immunized rats to reject tumor cell challenge. Both 13762 and ME/H carcinomata grow progressively and metastasize early to the retroperitoneal cavity and lungs if they are left untreated. Local radiotherapy of the primary tumor has no influence on growth of metastases whether it is combined with C. parvum ormore » not. Results of cell-mediated cytotoxicity studies with lymphocytes from BP 179 and ME/H tumor bearing rats treated with radiation or radiation plus C. parvum support the in vivo findings of combined radiotherapy. These data suggest that unlike strongly immunogenic tumors, weakly immunogenic tumors will not respond better to C. parvum combined with radiation therapy.« less

HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen

DOE PAGES

Jardine, Joseph G.; Kulp, Daniel W.; Havenar-Daughton, Colin; ...

2016-03-25

Induction of broadly neutralizing antibodies (bnAbs) is a major HIV vaccine goal. Germline-targeting immunogens aim to initiate bnAb induction by activating bnAb germline precursor B cells. Critical unmet challenges are to determine whether bnAb precursor naïve B cells bind germline-targeting immunogens and occur at sufficient frequency in humans for reliable vaccine responses. We employed deep mutational scanning and multi-target optimization to develop a germline-targeting immunogen (eOD-GT8) for diverse VRC01-class bnAbs. We then used the immunogen to isolate VRC01-class precursor naïve B cells from HIV-uninfected donors. Frequencies of true VRC01-class precursors, their structures, and their eOD-GT8 affinities support this immunogen asmore » a candidate human vaccine prime. Lastly, these methods could be applied to germline targeting for other classes of HIV bnAbs and for Abs to other pathogens.« less

HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, Joseph G.; Kulp, Daniel W.; Havenar-Daughton, Colin

Induction of broadly neutralizing antibodies (bnAbs) is a major HIV vaccine goal. Germline-targeting immunogens aim to initiate bnAb induction by activating bnAb germline precursor B cells. Critical unmet challenges are to determine whether bnAb precursor naïve B cells bind germline-targeting immunogens and occur at sufficient frequency in humans for reliable vaccine responses. We employed deep mutational scanning and multi-target optimization to develop a germline-targeting immunogen (eOD-GT8) for diverse VRC01-class bnAbs. We then used the immunogen to isolate VRC01-class precursor naïve B cells from HIV-uninfected donors. Frequencies of true VRC01-class precursors, their structures, and their eOD-GT8 affinities support this immunogen asmore » a candidate human vaccine prime. Lastly, these methods could be applied to germline targeting for other classes of HIV bnAbs and for Abs to other pathogens.« less

HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen.

PubMed

Jardine, Joseph G; Kulp, Daniel W; Havenar-Daughton, Colin; Sarkar, Anita; Briney, Bryan; Sok, Devin; Sesterhenn, Fabian; Ereño-Orbea, June; Kalyuzhniy, Oleksandr; Deresa, Isaiah; Hu, Xiaozhen; Spencer, Skye; Jones, Meaghan; Georgeson, Erik; Adachi, Yumiko; Kubitz, Michael; deCamp, Allan C; Julien, Jean-Philippe; Wilson, Ian A; Burton, Dennis R; Crotty, Shane; Schief, William R

2016-03-25

Induction of broadly neutralizing antibodies (bnAbs) is a major HIV vaccine goal. Germline-targeting immunogens aim to initiate bnAb induction by activating bnAb germline precursor B cells. Critical unmet challenges are to determine whether bnAb precursor naïve B cells bind germline-targeting immunogens and occur at sufficient frequency in humans for reliable vaccine responses. Using deep mutational scanning and multitarget optimization, we developed a germline-targeting immunogen (eOD-GT8) for diverse VRC01-class bnAbs. We then used the immunogen to isolate VRC01-class precursor naïve B cells from HIV-uninfected donors. Frequencies of true VRC01-class precursors, their structures, and their eOD-GT8 affinities support this immunogen as a candidate human vaccine prime. These methods could be applied to germline targeting for other classes of HIV bnAbs and for Abs to other pathogens. Copyright © 2016, American Association for the Advancement of Science.

[The immune system and the eye].

PubMed

Faber, Carsten; Nissen, Mogens Holst

2008-09-15

The special relationship between the eye and the immune system rests on a number of anatomical, physiological and immunological mechanisms. These mechanisms prevent the delicate structures of the eye from potentially damaging immunogenic inflammation while protecting against pathogens. Rather than inflammation, antigen induces a form of systemic and antigen-specific immunological tolerance. Owing to its systemic nature, this tolerance may be utilised to achieve successful treatment of immunological disorders.

Applications of Gold Nanoparticles in Nanomedicine: Recent Advances in Vaccines.

PubMed

Carabineiro, Sónia Alexandra Correia

2017-05-22

Nowadays, gold is used in (nano-)medicine, usually in the form of nanoparticles, due to the solid proofs given of its therapeutic effects on several diseases. Gold also plays an important role in the vaccine field as an adjuvant and a carrier, reducing toxicity, enhancing immunogenic activity, and providing stability in storage. An even brighter golden future is expected for gold applications in this area.

A Conformational Change of C Fragment of Tetanus Neurotoxin Reduces Its Ganglioside-Binding Activity but Does Not Destroy Its Immunogenicity ▿

PubMed Central

Yu, Rui; Yi, Shaoqiong; Yu, Changming; Fang, Ting; Liu, Shuling; Yu, Ting; Song, Xiaohong; Fu, Ling; Hou, Lihua; Chen, Wei

2011-01-01

The C fragment of tetanus neurotoxin (TeNT-Hc) with different conformations was observed due to the four cysteine residues within it which could form different intramolecular disulfide bonds. In this study, we prepared and compared three types of monomeric TeNT-Hc with different conformational components: free sulfhydryls (50 kDa), bound sulfhydryls (44 kDa), and a mixture of the two conformational proteins (half 50 kDa and half 44 kDa). TeNT-Hc with bound sulfhydryls reduced its binding activity to ganglioside GT1b and neuronal PC-12 cells compared to what was seen for TeNT-Hc with free sulfhydryls. However, there was no significant difference among their immunogenicities in mice, including induction of antitetanus toxoid IgG titers, antibody types, and protective capacities against tetanus neurotoxin challenge. Our results showed that the conformational changes of TeNT-Hc resulting from disulfide bond formation reduced its ganglioside-binding activity but did not destroy its immunogenicity, and the protein still retained continuous B cell and T cell epitopes; that is, the presence of the ganglioside-binding site within TeNT-Hc may be not essential for the induction of a fully protective antitetanus response. TeNT-Hc with bound sulfhydryls may be developed into an ideal human vaccine with a lower potential for side effects. PMID:21813664

Peptides containing antigenic and cationic domains have enhanced, multivalent immunogenicity when bound to DNA vaccines.

PubMed

Riedl, Petra; Reimann, Jörg; Schirmbeck, Reinhold

2004-02-01

We explored strategies to codeliver DNA- and peptide-based vaccines in a way that enhances the immunogenicity of both components of the combination vaccine for T cells. Specific CD8(+) T cell responses to an antigenic peptide are primed when the peptide is fused to a cationic peptide domain that is bound to plasmid DNA or oligonucleotides (ODN; with or without CpG motifs). Plasmid DNA mixed with antigenic/cationic peptides or histones forms large complexes with different biological properties depending on the molar ratios of peptide/protein and polynucleotide. Complexes containing high (but not low) molar ratios of cationic peptide to DNA facilitate transfection (DNA uptake and expression of the plasmid-encoded product) of cells. In contrast, complexes containing low (but not high) molar ratios of cationic peptide to DNA prime potent multispecific T cell responses after a single intramuscular injection of the complexes. The general validity of this observation was confirmed mixing different antigenic/cationic peptides with different DNA vaccines. In these vaccine formulations, multispecific CD8(+) T cell responses specific for epitopes of the peptide- as well as the DNA-based vaccine were efficiently coprimed, together with humoral antibody responses to conformational determinants of large viral antigens encoded by the DNA vaccine. The data indicate that mixtures of DNA vaccines with antigenic, cationic peptides are immunogenic vaccine formulations particularly suited for the induction of multispecific T cell responses.

Anchoring tick salivary anti-complement proteins IRAC I and IRAC II to membrane increases their immunogenicity

PubMed Central

Gillet, Laurent; Schroeder, Hélène; Mast, Jan; Thirion, Muriel; Renauld, Jean-Christophe; Dewals, Benjamin; Vanderplasschen, Alain

2009-01-01

Tick salivary proteins are promising targets for the development of anti-tick vaccines. Recently, we described two paralogous anti-complement proteins, called Ixodes ricinus anti-complement (IRAC) proteins I and II, that are co-expressed in tick I. ricinus salivary glands. However, our previous attempts to immunize rabbits against IRAC via infection with recombinant Bovine herpesvirus 4 (BoHV-4) vectors invariably failed although both recombinants expressed high levels of functional IRAC proteins in vitro. As IRAC are soluble monovalent antigens, one of the possible explanations is that monovalent ligation of the B-cell receptor induces receptor activation but fails to promote antigen presentation, a phenomenon that is thought to induce a state of B-cell tolerance. In the present study, we tried to increase IRAC immunogenicity by expressing them as oligovalent antigens. To this end, IRAC were fused to membrane anchors and BoHV-4 vectors expressing these recombinant forms were produced. The immunization potentials of recombinant viruses expressing either secreted or transmembrane IRAC proteins were then compared. While the former did not induce a detectable immune response against IRAC, the latter led to high titres of anti-IRAC antibodies that only marginally affected tick blood feeding. All together, the data presented in this study demonstrate that the immunogenicity of a soluble antigen can be greatly improved by anchoring it in membrane. PMID:19531344

Anchoring tick salivary anti-complement proteins IRAC I and IRAC II to membrane increases their immunogenicity.

PubMed

Gillet, Laurent; Schroeder, Hélène; Mast, Jan; Thirion, Muriel; Renauld, Jean-Christophe; Dewals, Benjamin; Vanderplasschen, Alain

2009-01-01

Tick salivary proteins are promising targets for the development of anti-tick vaccines. Recently, we described two paralogous anti-complement proteins, called Ixodes ricinus anti-complement (IRAC) proteins I and II, that are co-expressed in tick I. ricinus salivary glands. However, our previous attempts to immunize rabbits against IRAC via infection with recombinant Bovine herpesvirus 4 (BoHV-4) vectors invariably failed although both recombinants expressed high levels of functional IRAC proteins in vitro. As IRAC are soluble monovalent antigens, one of the possible explanations is that monovalent ligation of the B-cell receptor induces receptor activation but fails to promote antigen presentation, a phenomenon that is thought to induce a state of B-cell tolerance. In the present study, we tried to increase IRAC immunogenicity by expressing them as oligovalent antigens. To this end, IRAC were fused to membrane anchors and BoHV-4 vectors expressing these recombinant forms were produced. The immunization potentials of recombinant viruses expressing either secreted or transmembrane IRAC proteins were then compared. While the former did not induce a detectable immune response against IRAC, the latter led to high titres of anti-IRAC antibodies that only marginally affected tick blood feeding. All together, the data presented in this study demonstrate that the immunogenicity of a soluble antigen can be greatly improved by anchoring it in membrane.

The effect of in silico targeting Pseudomonas aeruginosa patatin-like protein D, for immunogenic administration.

PubMed

Chirani, Alireza Salimi; Majidzadeh, Robabeh; Pouriran, Ramin; Heidary, Mohsen; Nasiri, Mohammad Javad; Gholami, Mehrdad; Goudarzi, Mehdi; Omrani, Vahid Fallah

2018-02-05

The vaccine candidates that have been introduced for immunization against Pseudomonas aeruginosa (P. aeruginosa) strains are quite diverse. In fact, there has been no proper antigen to act as an effective immunogenic substance against this ubiquitous pathogen in the market as yet. The complications caused by this bacterium due to the rapid development of multiple drug resistant strains have led to clinical problems worldwide. P. aeruginosa encodes many specific virulence elements that could be used as appropriate vaccine candidates. Type Vd secretion system, also known as patatin-like protein D, is a novel P. aeruginosa auto-transporter system. It is known that cellular or humoral immune responses could be elevated by chimeric proteins carrying epitopes. It has been recognized that in silico tools are essential for the evaluation of new chimeric antigens. In this study, we have considered the patatin-like protein D (PlpD) molecule from P. aeruginosa and predicted some immunogenic properties of this strong cytotoxic phospholipase A2 with the use of in-depth computational and immunoinformatics assessment methods The novelty of our in silico study is the modeling and assessment of both humoral and cellular immune potential against the PlpD molecule. The molecule was considered by multiple sequence alignment and homology valuation. The extremely conserved regions in the PlpD were predicted. The allergenic and physicochemical property predictions on the PlpD state that the molecule is a non-allergic and stable molecule. High-resolution secondary and tertiary conformations were created. Indeed, the B-cell and T-cell epitope mapping on the chimeric target protein confirmed that the engineered protein contained a tremendous number of both B-cell and T-cell corresponding epitopes. This investigation magnificently attained the chimeric molecule as being a potent lipolytic enzyme composed of numerous B-cell and T-cell restricted epitopes and could induce both humoral and cellular immune responses. The results indicated that this molecule has therapeutic potential against several potent pathogenic P. aeruginosa strains. Copyright © 2018. Published by Elsevier Ltd.

Real-Life Efficacy, Immunogenicity and Safety of Biosimilar Infliximab.

PubMed

Vegh, Zsuzsanna; Kurti, Zsuzsanna; Lakatos, Peter L

2017-01-01

Recently, the use of biosimilar infliximab (IFX) in the treatment of inflammatory bowel diseases has become widespread in some European and non-European countries. Data on the efficacy, safety and immunogenicity from real-life cohorts are accumulating. The first reports showed similar outcomes in the induction and maintenance of remission, mucosal healing, safety and immunogenicity profile to the originator IFX. In the present review, we aimed to summarize the existing knowledge on the efficacy, safety and immunogenicity profile of biosimilar IFX reported from real-life cohorts. © 2017 S. Karger AG, Basel.

The mechanisms of Ag85A DNA vaccine activates RNA sensors through new signal transduction.

PubMed

Zhai, Jingbo; Wang, Qiubo; Gao, Yunfeng; Zhang, Ran; Li, Shengjun; Wei, Bing; You, Yong; Sun, Xun; Lu, Changlong

2018-06-01

Low immunogenicity is one of the major problems limiting the clinical use for DNA vaccines, which makes it impossible to obtain a strong protective immune response after vaccination. In order to explore whether Ag85A DNA vaccine could mount more efficiently protective immune response through new RNA sensor and its signal transduction pathway of antigen presentation we designed and synthesized Ag85A gene fragment containing multiple points mutations and transfected the gene fragment into the dendritic cell line (DC2.4) by CRISPR/Cas9. Subsequently, we focused on the changes of RNA sensors RIG-I, Mda-5, and the downstream adaptors MAVS, IRF3, IRF7 and IFN-β. The results indicated the significant increases in the mRNA and protein expression of RNA sensors RIG-I, Mda-5 and related adaptors MAVS, IRF3, IRF7, and IFN-β in the mutant DC 2.4 cells. The flow cytometry results demonstrated that the expression of MHC II on the surface of DC 2.4 significantly increased when compared with that in control. Therefore, it is suggested that Ag85A mutant DNA could release immunogenic message through RNA sensors and related adaptors via non protein pathway. There is at least one RNA signal transduction pathway of Ag85A DNA in DC2.4 cell. The work provides a new mode of action for nucleic acid vaccine to improve immunogenicity and meaningful data for the better understanding of the mechanisms of DNA vaccine. Copyright © 2017. Published by Elsevier B.V.

Strategies for Increasing Pancreatic Tumor Immunogenicity

PubMed Central

Johnson, Burles A.; Yarchoan, Mark; Lee, Valerie; Laheru, Daniel A.; Jaffee, Elizabeth M.

2017-01-01

Immunotherapy has changed the standard of care for multiple deadly cancers including lung, head and neck, gastric, and some colorectal cancers. However, single agent immunotherapy has had little effect in pancreatic adenocarcinoma (PDAC). Increasing evidence suggests that the PDAC microenvironment is comprised of an intricate network of signals between immune cells, PDAC cells, and stroma, resulting in an immunosuppressive environment resistant to single agent immunotherapies. In this review, we discuss differences between immunotherapy sensitive cancers and PDAC, the complex interactions between PDAC stroma and suppressive tumor infiltrating cells that facilitate PDAC development and progression, the immunologic targets within these complex networks that are drugable, and data supporting combination drug approaches that modulate multiple PDAC signals, which should lead to improved clinical outcomes. PMID:28373364

Applying biotin-streptavidin binding for iscom (immunostimulating complex) association of recombinant immunogens.

PubMed

Wikman, Maria; Friedman, Mikaela; Pinitkiatisakul, Sunan; Hemphill, Andrew; Lövgren-Bengtsson, Karin; Lundén, Anna; Ståhl, Stefan

2005-04-01

We have previously reported strategies for Escherichia coli production of recombinant immunogens fused to hydrophobic peptide or lipid tags to improve their capacity to be incorporated into an adjuvant formulation. In the present study, we have explored the strong interaction between biotin and SA (streptavidin) (K(D) approximately 10(-15) M) to couple recombinant immunogens to iscoms (immunostimulating complexes). Two different concepts were evaluated. In the first concept, a His(6)-tagged SA fusion protein (His(6)-SA) was bound to Ni(2+)-loaded iscom matrix (iscom without associated protein), and biotinylated immunogens were thereafter associated with the SA-coated iscoms. The immunogens were either biotinylated in vivo on E. coli expression or double biotinylated in vivo and in vitro. In the second concept, the recombinant immunogens were expressed as SA fusion proteins, which were directly bound to a biotinylated iscom matrix. A 53-amino-acid malaria peptide (M5), derived from the central repeat region of the Plasmodium falciparum blood-stage antigen Pf155/RESA, and a 232-amino-acid segment (SRS2') from the central region (from Pro-97 to Lys-328) of the major surface antigen NcSRS2 of the protozoan parasite Neospora caninum, served as model immunogens in the present study. All fusion proteins generated were found to be efficiently expressed and could be recovered to high purity using affinity chromatography. The association between the different immunogen-containing fusion proteins and the corresponding iscom matrix was demonstrated by analytical ultracentrifugation in a sucrose density gradient. However, some fusion proteins were, to a certain extent, also found to associate unspecifically with a regular iscom matrix. Furthermore, selected iscom fractions were demonstrated to induce high-titre antigen-specific antibody responses on immunization of mice. For the particular target immunogen SRS2', the induced antibodies demonstrated reactivity to the native antigen NcSRS2. We believe that the presented concepts offer convenient methods to achieve efficient adjuvant association of recombinant immunogens, and the advantages and disadvantages of the two concepts are discussed.

Identification of immunogenic proteins and evaluation of four recombinant proteins as potential vaccine antigens from Vibrio anguillarum in flounder (Paralichthys olivaceus).

PubMed

Xing, Jing; Xu, Hongsen; Wang, Yang; Tang, Xiaoqian; Sheng, Xiuzhen; Zhan, Wenbin

2017-05-31

Vibrio anguillarum is a severe bacterial pathogen that can infect a wide range of fish species. Identification of immunogenic proteins and development of vaccine are essential for disease prevention. In this study, immunogenic proteins were screened and identified from V. anguillarum, and then protective efficacy of the immunogenic proteins was evaluated. Immunogenic proteins in V. anguillarum whole cell were detected by Western blotting (WB) using immunized flounder (Paralichthys olivaceus) serum, and then identified by Mass spectrometry (MS). The recombinant proteins of four identified immunogenic proteins were produced and immunized to fish, and then percentages of surface membrane immunoglobulin-positive (sIg+) cells in peripheral blood lymphocytes (PBL), total antibodies, antibodies against V. anguillarum, antibodies against recombinant proteins and relative percent survival (RPS) were measured, respectively. The results showed that five immunogenic proteins, VAA, Groel, OmpU, PteF and SpK, were identified; their recombinant proteins, rOmpU, rGroel, rSpK and rVAA, could induce the proliferation of sIg+ cells in PBL and production of total antibodies, antibodies against V. anguillarum and antibodies against the recombinant proteins; their protection against V. anguillarum showed 64.86%, 72.97%, 21.62% and 78.38% RPS, respectively. The results revealed that the immunoproteomic technique using fish anti-V. anguillarum serum provided an efficient way to screen the immunogenic protein for vaccine antigen. Moreover, the rVAA, rGroel and rOmpU had potential to be vaccine candidates against V. anguillarum infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Towards Preserving the Immunogenicity of Protein Antigens Carried by Nanoparticles While Avoiding the Cold Chain

PubMed Central

Sloat, Brian R.; Sandoval, Michael A.; Cui, Zhengrong

2010-01-01

Nanoparticles are an attractive vaccine carrier with potent adjuvant activity. Data from our previous studies showed that immunization of mice with lecithin/glyceryl monostearate-based nanoparticles with protein antigens conjugated onto their surface induced a strong, quick, and long-lasting antigen-specific immune response. In the present study, we evaluated the feasibility of preserving the immunogenicity of protein antigens carried by nanoparticles without refrigeration using these antigen-conjugated nanoparticles as a model. The nanoparticles were lyophilized, and the immunogenicity of the antigens was evaluated in a mouse model using bovine serum albumin or the Bacillus anthracis protective antigen protein as model antigens. With proper excipients, the nanoparticles can be lyophilized while maintaining the immunogenicity of the antigens. Moreover, the immunogenicity of the model antigen conjugated onto the nanoparticles was undamaged after a relatively extended period of storage at room temperature or under accelerated conditions (37°C) when the nanoparticles were lyophilized with 5% mannitol plus 1% polyvinylpyrrolidone. To our knowledge, the present study represents an early attempt to preserve the immunogenicity of the protein antigens carried by nanoparticles without refrigeration. PMID:20416366

Statistical Linkage Analysis of Substitutions in Patient-Derived Sequences of Genotype 1a Hepatitis C Virus Nonstructural Protein 3 Exposes Targets for Immunogen Design

PubMed Central

Quadeer, Ahmed A.; Louie, Raymond H. Y.; Shekhar, Karthik; Chakraborty, Arup K.; Hsing, I-Ming

2014-01-01

ABSTRACT Chronic hepatitis C virus (HCV) infection is one of the leading causes of liver failure and liver cancer, affecting around 3% of the world's population. The extreme sequence variability of the virus resulting from error-prone replication has thwarted the discovery of a universal prophylactic vaccine. It is known that vigorous and multispecific cellular immune responses, involving both helper CD4+ and cytotoxic CD8+ T cells, are associated with the spontaneous clearance of acute HCV infection. Escape mutations in viral epitopes can, however, abrogate protective T-cell responses, leading to viral persistence and associated pathologies. Despite the propensity of the virus to mutate, there might still exist substitutions that incur a fitness cost. In this paper, we identify groups of coevolving residues within HCV nonstructural protein 3 (NS3) by analyzing diverse sequences of this protein using ideas from random matrix theory and associated methods. Our analyses indicate that one of these groups comprises a large percentage of residues for which HCV appears to resist multiple simultaneous substitutions. Targeting multiple residues in this group through vaccine-induced immune responses should either lead to viral recognition or elicit escape substitutions that compromise viral fitness. Our predictions are supported by published clinical data, which suggested that immune genotypes associated with spontaneous clearance of HCV preferentially recognized and targeted this vulnerable group of residues. Moreover, mapping the sites of this group onto the available protein structure provided insight into its functional significance. An epitope-based immunogen is proposed as an alternative to the NS3 epitopes in the peptide-based vaccine IC41. IMPORTANCE Despite much experimental work on HCV, a thorough statistical study of the HCV sequences for the purpose of immunogen design was missing in the literature. Such a study is vital to identify epistatic couplings among residues that can provide useful insights for designing a potent vaccine. In this work, ideas from random matrix theory were applied to characterize the statistics of substitutions within the diverse publicly available sequences of the genotype 1a HCV NS3 protein, leading to a group of sites for which HCV appears to resist simultaneous substitutions possibly due to deleterious effect on viral fitness. Our analysis leads to completely novel immunogen designs for HCV. In addition, the NS3 epitopes used in the recently proposed peptide-based vaccine IC41 were analyzed in the context of our framework. Our analysis predicts that alternative NS3 epitopes may be worth exploring as they might be more efficacious. PMID:24760894

Genotoxic effect and antigen binding characteristics of SLE auto-antibodies to peroxynitrite-modified human DNA.

PubMed

Khan, Md Asad; Alam, Khursheed; Mehdi, Syed Hassan; Rizvi, M Moshahid A

2017-12-01

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by auto-antibodies against native deoxyribonucleic acid after modification and is one of the reasons for the development of SLE. Here, we have evaluated the structural perturbations in human placental DNA by peroxynitrite using spectroscopy, thermal denaturation and high-performance liquid chromatography (HPLC). Peroxynitrite is a powerful potent bi-functional oxidative/nitrative agent that is produced both endogenously and exogenously. In experimental animals, the peroxynitrite-modified DNA was found to be highly immunogenic. The induced antibodies showed cross-reactions with different types of DNA and nitrogen bases that were modified with peroxynitrite by inhibition ELISA. The antibody activity was inhibited by approximately 89% with its immunogen as the inhibitor. The antigen-antibodies interaction between induced antibodies with peroxynitrite-modified DNA showed retarded mobility as compared to the native form. Furthermore, significantly increased binding was also observed in SLE autoantibodies with peroxynitrite-modified DNA than native form. Moreover, DNA isolated from lymphocyte of SLE patients revealed significant recognition of anti-peroxynitrite-modified DNA immunoglobulin G (IgG). Our data indicates that DNA modified with peroxynitrite presents unique antigenic determinants that may induce autoantibody response in SLE. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel fusion protein domain III-capsid from dengue-2, in a highly aggregated form, induces a functional immune response and protection in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valdes, Iris, E-mail: iris.valdes@cigb.edu.c; Bernardo, Lidice; Gil, Lazaro

Based on the immunogenicity of domain III from the Envelope protein of dengue virus as well as the proven protective capacity of the capsid antigen, we have designed a novel domain III-capsid chimeric protein with the goal of obtaining a molecule potentially able to induce both humoral and cell-mediated immunity (CMI). After expression of the recombinant gene in Escherichia coli, the domain III moiety retained its antigenicity as evaluated with anti-dengue sera. In order to explore alternatives for modulating the immunogenicity of the protein, it was mixed with oligodeoxynucleotides in order to obtain particulated aggregates and then immunologically evaluated inmore » mice in comparison with non-aggregated controls. Although the humoral immune response induced by both forms of the protein was equivalent, the aggregated variant resulted in a much stronger CMI as measured by in vitro IFN-gamma secretion and protection experiments, mediated by CD4{sup +} and CD8{sup +} cells. The present work provides additional evidence in support for a crucial role of CMI in protection against dengue virus and describes a novel vaccine candidate against the disease based on a recombinant protein that can stimulate both arms of the acquired immune system.« less

Role of gangliosides in active immunotherapy with melanoma vaccine.

PubMed

Ravindranath, M H; Morton, D L

1991-01-01

Among various tumor associated cell surface antigens, gangliosides, the glycosphingolipids that contain sialic acids, offer a variety of epitopes, some of which are preferentially expressed on melanoma cells. These surface components of the bilayered lipid membrane of tumor cells are the targets of active immunotherapy with melanoma vaccine. Purified gangliosides in aqueous solution form micelles and, at high density, form lactones. Their antigenic expression (physical conformation and orientation) on the cell surface is governed by the nature of the sphingosine and the fatty acids they contain. Evidence is accruing to show that the nature of the fatty acid moiety of gangliosides differs in normal and neoplastic cells. Gangliosides per se are not immunogenic and require extrinsic adjuvanticity. Preparation of a melanoma cell vaccine for active immunotherapy requires an understanding of the ganglioside profile of melanoma, the ganglioside-associated heterogeneity of melanoma, and the role of shed melanoma gangliosides in the immunosuppression of cell mediated and humoral immunity. In addition, the role of some of the anti-ganglioside antibodies in the elimination of shed gangliosides, the cytotoxic killing of tumor cells, as well as in the down-regulation of lymphocyte functions must be considered in the formulation of vaccine. Different strategies for augmenting the immunogenicity of melanoma associated gangliosides with melanoma vaccine are evaluated.

Short-chain consensus alpha-neurotoxin: a synthetic 60-mer peptide with generic traits and enhanced immunogenic properties.

PubMed

de la Rosa, Guillermo; Corrales-García, Ligia L; Rodriguez-Ruiz, Ximena; López-Vera, Estuardo; Corzo, Gerardo

2018-07-01

The three-fingered toxin family and more precisely short-chain α-neurotoxins (also known as Type I α-neurotoxins) are crucial in defining the elapid envenomation process, but paradoxically, they are barely neutralized by current elapid snake antivenoms. This work has been focused on the primary structural identity among Type I neurotoxins in order to create a consensus short-chain α-neurotoxin with conserved characteristics. A multiple sequence alignment considering the twelve most toxic short-chain α-neurotoxins reported from the venoms of the elapid genera Acanthophis, Oxyuranus, Walterinnesia, Naja, Dendroaspis and Micrurus led us to propose a short-chain consensus α-neurotoxin, here named ScNtx. The synthetic ScNtx gene was de novo constructed and cloned into the expression vector pQE30 containing a 6His-Tag and an FXa proteolytic cleavage region. Escherichia coli Origami cells transfected with the pQE30/ScNtx vector expressed the recombinant consensus neurotoxin in a soluble form with a yield of 1.5 mg/L of culture medium. The 60-amino acid residue ScNtx contains canonical structural motifs similar to α-neurotoxins from African elapids and its LD 50 of 3.8 µg/mice is similar to the most toxic short-chain α-neurotoxins reported from elapid venoms. Furthermore, ScNtx was also able to antagonize muscular, but not neuronal, nicotinic acetylcholine receptors (nAChR). Rabbits immunized with ScNtx were able to immune-recognize short-chain α-neurotoxins within whole elapid venoms. Type I neurotoxins are difficult to isolate and purify from natural sources; therefore, the heterologous expression of molecules such ScNtx, bearing crucial motifs and key amino acids, is a step forward to create common immunogens for developing cost-effective antivenoms with a wider spectrum of efficacy, quality and strong therapeutic value.

Application of M13 phage display for identifying immunogenic proteins from tick (Ixodes scapularis) saliva.

PubMed

Becker, Martin; Felsberger, André; Frenzel, André; Shattuck, Wendy M C; Dyer, Megan; Kügler, Jonas; Zantow, Jonas; Mather, Thomas N; Hust, Michael

2015-05-30

Ticks act as vectors for a large number of different pathogens, perhaps most notably Borrelia burgdorferi, the causative agent of Lyme disease. The most prominent tick vector in the United States is the blacklegged tick, Ixodes scapularis. Tick bites are of special public health concern since there are no vaccines available against most tick-transmitted pathogens. Based on the observation that certain non-natural host animals such as guinea pigs or humans can develop adaptive immune responses to tick bites, anti-tick vaccination is a potential approach to tackle health risks associated with tick bites. The aim of this study was to use an oligopeptide phage display strategy to identify immunogenic salivary gland proteins from I. scapularis that are recognized by human immune sera. Oligopeptide libraries were generated from salivary gland mRNA of 18 h fed nymphal I. scapularis. Eight immunogenic oligopeptides were selected using human immune sera. Three selected immunogenic oligopeptides were cloned and produced as recombinant proteins. The immunogenic character of an identified metalloprotease (MP1) was validated with human sera. This enzyme has been described previously and was hypothesized as immunogenic which was confirmed in this study. Interestingly, it also has close homologs in other Ixodes species. An immunogenic protein of I. scapularis was identified by oligopeptide phage display. MP1 is a potential candidate for vaccine development.

Diversification of the celiac disease α-gliadin complex in wheat: a 33-mer peptide with six overlapping epitopes, evolved following polyploidization.

PubMed

Ozuna, Carmen V; Iehisa, Julio C M; Giménez, María J; Alvarez, Juan B; Sousa, Carolina; Barro, Francisco

2015-06-01

The gluten proteins from wheat, barley and rye are responsible both for celiac disease (CD) and for non-celiac gluten sensitivity, two pathologies affecting up to 6-8% of the human population worldwide. The wheat α-gliadin proteins contain three major CD immunogenic peptides: p31-43, which induces the innate immune response; the 33-mer, formed by six overlapping copies of three highly stimulatory epitopes; and an additional DQ2.5-glia-α3 epitope which partially overlaps with the 33-mer. Next-generation sequencing (NGS) and Sanger sequencing of α-gliadin genes from diploid and polyploid wheat provided six types of α-gliadins (named 1-6) with strong differences in their frequencies in diploid and polyploid wheat, and in the presence and abundance of these CD immunogenic peptides. Immunogenic variants of the p31-43 peptide were found in most of the α-gliadins. Variants of the DQ2.5-glia-α3 epitope were associated with specific types of α-gliadins. Remarkably, only type 1 α-gliadins contained 33-mer epitopes. Moreover, the full immunodominant 33-mer fragment was only present in hexaploid wheat at low abundance, probably as the result of allohexaploidization events from subtype 1.2 α-gliadins found only in Aegilops tauschii, the D-genome donor of hexaploid wheat. Type 3 α-gliadins seem to be the ancestral type as they are found in most of the α-gliadin-expressing Triticeae species. These findings are important for reducing the incidence of CD by the breeding/selection of wheat varieties with low stimulatory capacity of T cells. Moreover, advanced genome-editing techniques (TALENs, CRISPR) will be easier to implement on the small group of α-gliadins containing only immunogenic peptides. © 2015 Society for Experimental Biology and John Wiley & Sons Ltd.

Encoded novel forms of HSP70 or a cytolytic protein increase DNA vaccine potency.

PubMed

Garrod, Tamsin; Grubor-Bauk, Branka; Yu, Stanley; Gargett, Tessa; Gowans, Eric J

2014-01-01

In humans, DNA vaccines have failed to demonstrate the equivalent levels of immunogenicity that were shown in smaller animals. Previous studies have encoded adjuvants, predominantly cytokines, within these vaccines in an attempt to increase antigen-specific immune responses. However, these strategies have lacked breadth of innate immune activation and have led to disappointing results in clinical trials. Damage associated molecular patterns (DAMPs) have been identified as pattern recognition receptor (PRR) agonists. DAMPs can bind to a wide range of PRRs on dendritic cells (DCs) and thus our studies have aimed to utilize this characteristic to act as an adjuvant in a DNA vaccine approach. Specifically, HSP70 has been identified as a DAMP, but has been limited by its lack of accessibility to PRRs in and on DCs. Here, we discuss the promising results achieved with the inclusion of membrane-bound or secreted HSP70 into a DNA vaccine encoding HIV gag as the model immunogen.

Immunogenicity and therapeutic effects of a Mycobacterium tuberculosis rv2190c DNA vaccine in mice.

PubMed

Liang, Yan; Zhang, Xiaoyan; Bai, Xuejuan; Xiao, Li; Wang, Xiaomei; Zhang, Junxian; Yang, Yourong; Song, Jinying; Wang, Lan; Wu, Xueqiong

2017-02-27

Tuberculosis (TB) is a major global public health problem. New treatment methods on TB are urgently demanded. In this study, Mycobacterium tuberculosis (MTB) rv2190c DNA vaccine was prepared and its immunogenicity and therapeutic effects were evaluated. Non-infected mice immunized with rv2190c DNA or ag85a DNA showed higher levels of interferon-gamma (IFN-γ) in stimulated spleen lymphocyte culture supernatants, and had more Th1 cells and an elevatory ratio of Th1/Th2 immune cells in whole blood, indicating that Th1-type immune response was predominant. Compared with the saline group, ag85a DNA group and rv2190c DNA group in the infected mice decreased the lung colony-forming units (CFUs) by 0.533 and 0.283 log 10 , and spleen CFUs by 0.425 and 0.321 log 10 respectively, and pathological lesion. The rv2190c DNA had some immunotherapeutic effect on TB.

High-throughput identification and dendritic cell-based functional validation of MHC class I-restricted Mycobacterium tuberculosis epitopes

PubMed Central

Nair, Smita K.; Tomaras, Georgia D.; Sales, Ana Paula; Boczkowski, David; Chan, Cliburn; Plonk, Kelly; Cai, Yongting; Dannull, Jens; Kepler, Thomas B.; Pruitt, Scott K.; Weinhold, Kent J.

2014-01-01

Emergence of drug-resistant strains of the pathogen Mycobacterium tuberculosis (Mtb) and the ineffectiveness of BCG in curtailing Mtb infection makes vaccine development for tuberculosis an important objective. Identifying immunogenic CD8+ T cell peptide epitopes is necessary for peptide-based vaccine strategies. We present a three-tiered strategy for identifying and validating immunogenic peptides: first, identify peptides that form stable complexes with class I MHC molecules; second, determine whether cytotoxic T lymphocytes (CTLs) raised against the whole protein antigen recognize and lyse target cells pulsed with peptides that passed step 1; third, determine whether peptides that passed step 2, when administered in vivo as a vaccine in HLA-A2 transgenic mice, elicit CTLs that lyse target cells expressing the whole protein antigen. Our innovative approach uses dendritic cells transfected with Mtb antigen-encoding mRNA to drive antigen expression. Using this strategy, we have identified five novel peptide epitopes from the Mtb proteins Apa, Mtb8.4 and Mtb19. PMID:24755960

Mosaic vaccines elicit CD8+ T cell responses in monkeys that confer immune coverage of diverse HIV strains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, Will; Korber, Bette

2009-01-01

Creation of a successful HIV vaccine will require the development of a strategy to generate cellular immunity with sufficient cross-clade breadth to deal with the extreme genetic diversity of the virus. Polyvalent mosaic immunogens derived from in silica recombination of natural strains of HIV are designed to induce cellular immune responses that maximally cover the sequence diversity of circulating virus isolates. Immunization of rhesus monkeys with plasmid DNA and recombinant vaccinia virus vaccine constructs expressing either consensus immunogens or polyvalent mosaic immunogens elicited a CD4+ T lymphocyte-biased response with comparably broad epitope-specific total T lymphocyte specificities. However, immunization with themore » mosaic immunogens induced HIV-specific CD8+ T lymphocyte responses with markedly greater depth and breadth. Therefore, the use of polyvalent mosaic immunogens is a promising strategy for a global vaccine for HIV.« less

The formulation and immunogenicity of therapeutic proteins: Product quality as a key factor.

PubMed

Richard, Joel; Prang, Nadia

2010-08-01

The formation of anti-drug antibodies represents a risk that should be assessed carefully during biopharmaceutical drug product (DP) development, as such antibodies compromise safety and efficacy and may alter the pharmacokinetic properties of a compound. This feature review discusses immunogenicity issues in biopharmaceutical DP development, with a focus on product quality. Excipient-induced and aggregate-induced immunogenicity are reviewed based on the concepts of 'aggregation-competent' species and 'provocative' aggregates. In addition, the influence of formulation parameters, such as particulates and contaminants appearing in the DP during processing and storage, on aggregate-induced immunogenicity are presented, including the role of fill-and-finish equipments and the effect of interactions with container materials. Furthermore, methods to detect and quantify aggregation and precursor conformational changes in a protein formulation are reviewed, and immunological mechanisms that may lead to aggregate-induced immunogenicity are proposed and discussed.

Carbon nanotubes as vaccine scaffolds

PubMed Central

Scheinberg, David A.; McDevitt, Michael R.; Dao, Tao; Mulvey, Justin J.; Feinberg, Evan; Alidori, Simone

2013-01-01

Carbon nanotubes display characteristics that are potentially useful in their development as scaffolds for vaccine compositions. These features include stability in vivo, lack of intrinsic immunogenicity, low toxicity, and the ability to be appended with multiple copies of antigens. In addition, the particulate nature of carbon nanotubes and their unusual properties of rapid entry into antigen-presenting cells, such as dendritic cells, make them especially useful as carriers of antigens. Early attempts demonstrating carbon nanotube-based vaccines can be used in both infectious disease settings and cancer are promising. PMID:23899863

Immunogenicity of biotherapy used in psoriasis: the science behind the scenes.

PubMed

Jullien, Denis; Prinz, Jörg C; Nestle, Frank O

2015-01-01

A potential limitation in the use of biologic drugs used to treat psoriasis is the development of anti-drug antibodies (ADAs). Many factors contribute to this unwanted immune response, from the product itself, to its mode of administration, the underlying disease, and patient characteristics. ADAs may decrease the efficacy of biologic drugs by neutralizing them or modifying their clearance and may account for hypersensitivity reactions. This article reviews the scientific basis of immunogenicity and the mechanisms by which it affects clinical outcomes. It also considers testing for immunogenicity and how biologic therapy of psoriasis may be tailored on the basis of immunogenicity.

Towards preserving the immunogenicity of protein antigens carried by nanoparticles while avoiding the cold chain.

PubMed

Sloat, Brian R; Sandoval, Michael A; Cui, Zhengrong

2010-06-30

Nanoparticles are an attractive vaccine carrier with potent adjuvant activity. Data from our previous studies showed that immunization of mice with lecithin/glyceryl monostearate-based nanoparticles with protein antigens conjugated onto their surface induced a strong, quick, and long-lasting antigen-specific immune response. In the present study, we evaluated the feasibility of preserving the immunogenicity of protein antigens carried by nanoparticles without refrigeration using these antigen-conjugated nanoparticles as a model. The nanoparticles were lyophilized, and the immunogenicity of the antigens was evaluated in a mouse model using bovine serum albumin or the Bacillus anthracis protective antigen protein as model antigens. With proper excipients, the nanoparticles can be lyophilized while maintaining the immunogenicity of the antigens. Moreover, the immunogenicity of the model antigen conjugated onto the nanoparticles was undamaged after a relatively extended period of storage at room temperature or under accelerated conditions (37 degrees C) when the nanoparticles were lyophilized with 5% mannitol plus 1% polyvinylpyrrolidone. To our knowledge, the present study represents an early attempt to preserve the immunogenicity of the protein antigens carried by nanoparticles without refrigeration. 2010 Elsevier B.V. All rights reserved.

The Role of Immunogenicity in Cardiovascular Disease

PubMed Central

Jan, Michael; Virtue, Anthony T.; Pansuria, Meghanaben; Liu, Jingshan; Xiong, Xinyu; Fang, Pu; Meng, Shu; Wang, Hong; Yang, Xiao-Feng

2012-01-01

Recently, many of the complexities associated with cardiovascular diseases (CVD) have been unlocked. However, despite these breakthroughs, CVD and its related complications are the leading contributors of morbidity and mortality worldwide, which indicates the shortcomings of current treatment regimens and the need for continued research. Published data within the field clearly indicates that CVD are built on inflammation and autoimmune platforms, though a strong, fundamental understanding of the mechanisms remains elusive. Areas such as the mechanisms underlying increased immunogenicity of self-proteins in the cardiovascular system, the roles of immunogenic auto-antigens in eliciting inflammatory autoimmune responses, and the immunosuppressive mechanisms involved in controlling inflammatory and autoimmune cardiovascular diseases remain to be well-understood. We will delve into these topics and the advancements made within the field in this review. Specifically, we will concentrate on the innate and adaptive immune responses mediating immunogenicity; the mechanisms of inflammation and autoimmunity in atherogenesis; the mechanisms of inflammation and autoimmunity in diabetic atherosclerosis; immunogenicity and stem cell therapy; as well as immunogenicity and immunosuppression. In depth examination and comprehension of these topics will provide insight into the recent progress of the field and bring to the forefront potentially novel therapeutic avenues. PMID:24511305

Understanding the immunogenicity and antigenicity of nanomaterials: Past, present and future

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilinskaya, Anna N.; Dobrovolskaia, Marina A., E-ma

Nanoparticle immunogenicity and antigenicity have been under investigation for many years. During the past decade, significant progress has been made in understanding what makes a nanoparticle immunogenic, how immune cells respond to nanoparticles, what consequences of nanoparticle-specific antibody formation exist and how they challenge the application of nanoparticles for drug delivery. Moreover, it has been recognized that accidental contamination of therapeutic protein formulations with nanosized particulate materials may contribute to the immunogenicity of this type of biotechnology products. While the immunological properties of engineered nanomaterials and their application as vaccine carriers and adjuvants have been given substantial consideration in themore » current literature, little attention has been paid to nanoparticle immuno- and antigenicity. To fill in this gap, we herein provide an overview of this subject to highlight the current state of the field, review past and present research, and discuss future research directions. - Highlights: • Most engineered nanomaterials are not immunogenic per se. • Generation of nanoparticle-specific antibody can be T-cell dependent or independent. • Antibodies can be generated to particle core, terminal groups or surface coatings. • Engineered and accidental nanomaterials have distinct contribution to immunogenicity. • Tunable physicochemical properties make each nanoparticle unique.« less

Identification of In Vivo-Expressed Immunogenic Proteins by Serological Proteome Analysis of the Bacillus anthracis Secretome▿ †

PubMed Central

Chitlaru, Theodor; Gat, Orit; Grosfeld, Haim; Inbar, Itzhak; Gozlan, Yael; Shafferman, Avigdor

2007-01-01

In a previous comparative proteomic study of Bacillus anthracis examining the influence of the virulence plasmids and of various growth conditions on the composition of the bacterial secretome, we identified 64 abundantly expressed proteins (T. Chitlaru, O. Gat, Y. Gozlan, N. Ariel, and A. Shafferman, J. Bacteriol. 188:3551-3571, 2006). Using a battery of sera from B. anthracis-infected animals, in the present study we demonstrated that 49 of these proteins are immunogenic. Thirty-eight B. anthracis immunogens are documented in this study for the first time. The relative immunogenicities of the 49 secreted proteins appear to span a >10,000-fold range. The proteins eliciting the highest humoral response in the course of infection include, in addition to the well-established immunogens protective antigen (PA), Sap, and EA1, GroEL (BA0267), AhpC (BA0345), MntA (BA3189), HtrA (BA3660), 2,3-cyclic nucleotide diesterase (BA4346), collagen adhesin (BAS5205), an alanine amidase (BA0898), and an endopeptidase (BA1952), as well as three proteins having unknown functions (BA0796, BA0799, and BA0307). Of these 14 highly potent secreted immunogens, 11 are known to be associated with virulence and pathogenicity in B. anthracis or in other bacterial pathogens. Combining the results reported here with the results of a similar study of the membranal proteome of B. anthracis (T. Chitlaru, N. Ariel, A. Zvi, M. Lion, B. Velan, A. Shafferman, and E. Elhanany, Proteomics 4:677-691, 2004) and the results obtained in a functional genomic search for immunogens (O. Gat, H. Grosfeld, N. Ariel, I. Inbar, G. Zaide, Y. Broder, A. Zvi, T. Chitlaru, Z. Altboum, D. Stein, S. Cohen, and A. Shafferman, Infect. Immun. 74:3987-4001, 2006), we generated a list of 84 in vivo-expressed immunogens for future evaluation for vaccine development, diagnostics, and/or therapeutic intervention. In a preliminary study, the efficacies of eight immunogens following DNA immunization of guinea pigs were compared to the efficacy of a PA DNA vaccine. All eight immunogens induced specific high antibody titers comparable to the titers elicited by PA; however, unlike PA, none of them provided protection against a lethal challenge (50 50% lethal doses) of virulent B. anthracis strain Vollum spores. PMID:17353282

Species specificity, surface exposure, protein expression, immunogenicity, and participation in biofilm formation of Porphyromonas gingivalis HmuY

PubMed Central

2010-01-01

Background Porphyromonas gingivalis is a major etiological agent of chronic periodontitis. The aim of this study was to examine the species specificity, surface exposure, protein expression, immunogenicity, and participation in biofilm formation of the P. gingivalis heme-binding protein HmuY. Results HmuY is a unique protein of P. gingivalis since only low amino-acid sequence homology has been found to proteins encoded in other species. It is exposed on the cell surface and highly abundant in the outer membrane of the cell, in outer-membrane vesicles, and is released into culture medium in a soluble form. The protein is produced constitutively at low levels in bacteria grown under high-iron/heme conditions and at higher levels in bacteria growing under the low-iron/heme conditions typical of dental plaque. HmuY is immunogenic and elicits high IgG antibody titers in rabbits. It is also engaged in homotypic biofilm formation by P. gingivalis. Anti-HmuY antibodies exhibit inhibitory activity against P. gingivalis growth and biofilm formation. Conclusions Here it is demonstrated that HmuY may play a significant role not only in heme acquisition, but also in biofilm accumulation on abiotic surfaces. The data also suggest that HmuY, as a surface-exposed protein, would be available for recognition by the immune response during chronic periodontitis and the production of anti-HmuY antibodies may inhibit biofilm formation. PMID:20438645

Prolongation of the survival of breast cancer-bearing mice immunized with GM-CSF-secreting syngeneic/allogeneic fibroblasts transfected with a cDNA expression library from breast cancer cells.

PubMed

Kim, Tae S; Jung, Mi Y; Cho, Daeho; Cohen, Edward P

2006-10-30

Breast cancer cells, like other types of neoplastic cells, form weakly immunogenic tumor-associated antigens. The antigenic properties of the tumor-associated antigens can be enhanced if they are expressed by highly immunogenic cells. In this study, a cancer vaccine was prepared by transfer of a cDNA expression library from SB5b breast carcinoma into mouse fibroblast cells of C3H/He mouse origin (H-2(k)), that had been previously modified to secrete GM-CSF and to express allogeneic class I-determinants (H-2(b)). The transfected syngeneic/allogeneic fibroblasts secreting GM-CSF were used as a vaccine in C3H/He mice. Robust cell-mediated immunity toward the breast cancer cells was generated in mice immunized with the cDNA-based vaccine. The immunity, mediated predominantly by CD8(+) T lymphocytes, was directed toward the breast cancer cells, but not against either of two other non-cross-reactive neoplasms of C3H/He mice. The immunity was sufficient to prolong the survival of mice with established breast cancer. Among other advantages, preparation of the vaccine by cDNA-transfer into a fibroblast cell line enabled the recipient cells to be modified in advance of DNA-transfer to augment their immunogenic properties. As the transferred DNA is replicated as the transfected cells divide, the vaccine could be prepared from microgram quantities of tumor tissue.

A functional whole blood assay to measure viability of mycobacteria, using reporter-gene tagged BCG or M.Tb (BCGlux/M.Tb lux).

PubMed

Newton, Sandra; Martineau, Adrian; Kampmann, Beate

2011-09-14

Functional assays have long played a key role in measuring of immunogenicity of a given vaccine. This is conventionally expressed as serum bactericidal titers. Studies of serum bactericidal titers in response to childhood vaccines have enabled us to develop and validate cut-off levels for protective immune responses and such cut-offs are in routine use. No such assays have been taken forward into the routine assessment of vaccines that induce primarily cell-mediated immunity in the form of effector T cell responses, such as TB vaccines. In the animal model, the performance of a given vaccine candidate is routinely evaluated in standardized bactericidal assays, and all current novel TB-vaccine candidates have been subjected to this step in their evaluation prior to phase 1 human trials. The assessment of immunogenicity and therefore likelihood of protective efficacy of novel anti-TB vaccines should ideally undergo a similar step-wise evaluation in the human models now, including measurements in bactericidal assays. Bactericidal assays in the context of tuberculosis vaccine research are already well established in the animal models, where they are applied to screen potentially promising vaccine candidates. Reduction of bacterial load in various organs functions as the main read-out of immunogenicity. However, no such assays have been incorporated into clinical trials for novel anti-TB vaccines to date. Although there is still uncertainty about the exact mechanisms that lead to killing of mycobacteria inside human macrophages, the interaction of macrophages and T cells with mycobacteria is clearly required. The assay described in this paper represents a novel generation of bactericidal assays that enables studies of such key cellular components with all other cellular and humoral factors present in whole blood without making assumptions about their relative individual contribution. The assay described by our group uses small volumes of whole blood and has already been employed in studies of adults and children in TB-endemic settings. We have shown immunogenicity of the BCG vaccine, increased growth of mycobacteria in HIV-positive patients, as well as the effect of anti-retroviral therapy and Vitamin D on mycobacterial survival in vitro. Here we summarise the methodology, and present our reproducibility data using this relatively simple, low-cost and field-friendly model. Note: Definitions/Abbreviations BCG lux = M. bovis BCG, Montreal strain, transformed with shuttle plasmid pSMT1 carrying the luxAB genes from Vibrio harveyi, under the control of the mycobacterial GroEL (hsp60) promoter. CFU = Colony Forming Unit (a measure of mycobacterial viability).

Immunogenicity of a chimeric peptide corresponding to T helper and B cell epitopes of the Chlamydia trachomatis major outer membrane protein

PubMed Central

1992-01-01

The immunogenicity of a chimeric T/B cell peptide corresponding to antigenically characterized epitopes of the Chlamydia trachomatis major outer membrane protein (MOMP) was studied in mice to further define its potential use in the development of a subunit vaccine in preventing blinding trachoma in humans. The chimeric peptide, designated A8-VDI, corresponds to a conserved MOMP T helper (Th) cell epitope(s) (A8, residues 106-130) and serovar A VDI (residues 66-80), which contains the serovar-specific neutralizing epitope 71VAGLEK76. Mice immunized with peptide A8-VDI produced high-titered polyclonal IgG antibodies which recognized the VAGLEK-neutralizing epitope. Peptide A8-VDI primed A/J mice to produce high-titered serum-neutralizing antibodies in response to a secondary immunization with intact chlamydial elementary bodies (EBs). Peptide A8-VDI, but not peptide VDI alone, was immunogenic in six different inbred strains of mice disparate at H-2, indicating that the Th cell epitope(s) contained in the A8 portion of the chimera was recognized in the context of multiple major histocompatibility complex (MHC) haplotypes. An unexpected finding of this work was that different inbred strains of mice immunized with the chimeric peptide produced antibodies of differing fine specificities to the VDI portion of the chimera. Some mouse strains produced anti-VDI antibodies that did not recognize the VAGLEK-neutralizing epitope. The ability of mice to respond to the VAGLEK-neutralizing site was not dependent on MHC haplotype since mouse strains of the same H-2 haplotype produced anti-VDI antibodies of differing fine specificity. PMID:1370528

Control of humoral immunity and auto-immunity by the CXCR4/CXCL12 axis in lupus patients following influenza vaccine.

PubMed

Launay, Odile; Paul, Stéphane; Servettaz, Amélie; Roguet, Gwénaëlle; Rozenberg, Flore; Lucht, Frédéric; Lambert, Claude; Presles, Emilie; Goulvestre, Claire; Méritet, Jean-François; Galtier, Florence; Dubray, Claude; Lebon, Pierre; Weill, Bernard; Batteux, Frédéric

2013-08-02

CXCR4 is a chemokine receptor with multiple effects on the immune system, upregulated in patients with SLE, and correlated with disease severity. This study has investigated whether the levels of CXCR4 expressed on leucocyte subsets in lupus patients are correlated with the efficacy and the safety of the influenza vaccine. Twenty-seven patients were vaccinated and vaccine immunogenicity and tolerance were evaluated. CXCR4 was assayed on leucocyte subsets and correlated with clinical and immunological signs of diseases activity. A significant increase in the titres of antibodies to the three viral strains was observed along with trends towards an increased vaccine efficacy in patients with quiescent disease vs patients with active disease. Recent flu vaccine history and, to a lesser extent, immunosuppressive treatment may influence vaccine immunogenicity. Influenza immunization was not associated with clinical side-effects or clinical lupus flare but with an increase in rheumatoid factor levels. Our study also confirms the correlation of CXCR4 expression with biological autoimmunity as shown by the correlation between the percentage of CXCR4-positive T cells and the ANA titres at D0, and the reverse correlation between CXCR4 expression and vaccine immunogenicity as demonstrated by the higher percentage of CXCR4-positive T cells at D0 and D30 in non-responders vs responders. Altogether, our study confirms the efficacy and the safety of flu vaccine in SLE patients, highlights the role of CXCR4 as a surrogate marker for autoimmunity in lupus and shows that CXCR4 expression on T cells is predictive of vaccine efficacy in SLE patients. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Measles Virus Hemagglutinin epitopes immunogenic in natural infection and vaccination are targeted by broad or genotype-specific neutralizing monoclonal antibodies.

PubMed

Muñoz-Alía, Miguel Angel; Casasnovas, José M; Celma, María Luisa; Carabaña, Juan; Liton, Paloma B; Fernandez-Muñoz, Rafael

2017-05-15

Measles virus (MV) remains a leading cause of vaccine-preventable deaths in children. Protection against MV is associated with neutralizing antibodies that preferentially recognize the viral hemagglutinin (MV-H), and to a lesser extent, the fusion protein (MV-F). Although MV is serologically monotypic, 24 genotypes have been identified. Here we report three neutralization epitopes conserved in the more prevalent circulating MV genotypes, two located in the MV-H receptor binding site (RBS) (antigenic site III) and a third in MV-H/MV-F interphase (antigenic site Ia) which are essential for MV multiplication. In contrast, two MV-H neutralization epitopes, showed a genotype-specific neutralization escape due to a single amino acid change, that we mapped in the "noose" antigenic site, or an enhanced neutralization epitope (antigenic site IIa). The monoclonal antibody (mAb) neutralization potency correlated with its binding affinity and was mainly driven by kinetic dissociation rate (k off ). We developed an immunoassay for mAb binding to MV-H in its native hetero-oligomeric structure with MV-F on the surface of a MV productive steady-state persistently infected (p.i.) human cell lines, and a competitive-binding assay with serum from individuals with past infection by different MV genotypes. Binding assays revealed that a broad neutralization epitope, in RBS antigenic site, a genotype specific neutralization epitopes, in noose and IIa sites, were immunogenic in natural infection and vaccination and may elicit long-lasting humoral immunity that might contribute to explain MV immunogenic stability. These results support the design of improved measles vaccines, broad-spectrum prophylactic or therapeutic antibodies and MV-used in oncolytic therapies. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of pre-existing antibody presence as a risk factor for posttreatment anti-drug antibody induction: analysis of human clinical study data for multiple biotherapeutics.

PubMed

Xue, Li; Rup, Bonita

2013-07-01

Biotherapeutic-reactive antibodies in treatment-naïve subjects (i.e., pre-existing antibodies) have been commonly detected during clinical immunogenicity assessments; however information on pre-existing antibody prevalence, physiological effects, and impact on posttreatment anti-drug antibody (ADA) induction remains limited. In this analysis, pre-existing antibody prevalence and impact on posttreatment ADA induction were determined using ADA data from 12 biotherapeutics analyzed in 32 clinical studies. Approximately half (58%) of the biotherapeutics were associated with some level of pre-existing antibodies and 67% of those were associated with posttreatment ADA induction. Across all studies, 5.6% of study subjects demonstrated presence of pre-existing antibodies, among which, 17% of the individual subjects had posttreatment increases in their ADA titers while 16% had decreased titers and 67% had no change in titers. However, in studies conducted in the rheumatoid arthritis (RA) population, 14.8% of RA patients were associated with pre-existing antibodies and 30% of those had posttreatment titer increases. The results suggest that in most study subjects, pre-existing antibodies pose a low risk for posttreatment ADA induction. That said, the high risk of induction implicated for RA patients, primarily observed in treatments evaluating novel antibody-based constructs, indicates that further understanding of the contribution of product and disease-specific factors is needed. Cross-industry efforts to collect and analyze a larger data set would enhance understanding of the prevalence, nature, and physiological consequences of pre-existing antibodies, better inform the immunogenicity risk profiles of products associated with these antibodies and lead to better fit-for-purpose immunogenicity management and mitigation strategies.

The influence of delivery vectors on HIV vaccine efficacy

PubMed Central

Ondondo, Beatrice O.

2014-01-01

Development of an effective HIV/AIDS vaccine remains a big challenge, largely due to the enormous HIV diversity which propels immune escape. Thus novel vaccine strategies are targeting multiple variants of conserved antibody and T cell epitopic regions which would incur a huge fitness cost to the virus in the event of mutational escape. Besides immunogen design, the delivery modality is critical for vaccine potency and efficacy, and should be carefully selected in order to not only maximize transgene expression, but to also enhance the immuno-stimulatory potential to activate innate and adaptive immune systems. To date, five HIV vaccine candidates have been evaluated for efficacy and protection from acquisition was only achieved in a small proportion of vaccinees in the RV144 study which used a canarypox vector for delivery. Conversely, in the STEP study (HVTN 502) where human adenovirus serotype 5 (Ad5) was used, strong immune responses were induced but vaccination was more associated with increased risk of HIV acquisition than protection in vaccinees with pre-existing Ad5 immunity. The possibility that pre-existing immunity to a highly promising delivery vector may alter the natural course of HIV to increase acquisition risk is quite worrisome and a huge setback for HIV vaccine development. Thus, HIV vaccine development efforts are now geared toward delivery platforms which attain superior immunogenicity while concurrently limiting potential catastrophic effects likely to arise from pre-existing immunity or vector-related immuno-modulation. However, it still remains unclear whether it is poor immunogenicity of HIV antigens or substandard immunological potency of the safer delivery vectors that has limited the success of HIV vaccines. This article discusses some of the promising delivery vectors to be harnessed for improved HIV vaccine efficacy. PMID:25202303

An RLP23-SOBIR1-BAK1 complex mediates NLP-triggered immunity.

PubMed

Albert, Isabell; Böhm, Hannah; Albert, Markus; Feiler, Christina E; Imkampe, Julia; Wallmeroth, Niklas; Brancato, Caterina; Raaymakers, Tom M; Oome, Stan; Zhang, Heqiao; Krol, Elzbieta; Grefen, Christopher; Gust, Andrea A; Chai, Jijie; Hedrich, Rainer; Van den Ackerveken, Guido; Nürnberger, Thorsten

2015-10-05

Plants and animals employ innate immune systems to cope with microbial infection. Pattern-triggered immunity relies on the recognition of microbe-derived patterns by pattern recognition receptors (PRRs). Necrosis and ethylene-inducing peptide 1-like proteins (NLPs) constitute plant immunogenic patterns that are unique, as these proteins are produced by multiple prokaryotic (bacterial) and eukaryotic (fungal, oomycete) species. Here we show that the leucine-rich repeat receptor protein (LRR-RP) RLP23 binds in vivo to a conserved 20-amino-acid fragment found in most NLPs (nlp20), thereby mediating immune activation in Arabidopsis thaliana. RLP23 forms a constitutive, ligand-independent complex with the LRR receptor kinase (LRR-RK) SOBIR1 (Suppressor of Brassinosteroid insensitive 1 (BRI1)-associated kinase (BAK1)-interacting receptor kinase 1), and recruits a second LRR-RK, BAK1, into a tripartite complex upon ligand binding. Stable, ectopic expression of RLP23 in potato (Solanum tuberosum) confers nlp20 pattern recognition and enhanced immunity to destructive oomycete and fungal plant pathogens, such as Phytophthora infestans and Sclerotinia sclerotiorum. PRRs that recognize widespread microbial patterns might be particularly suited for engineering immunity in crop plants.

Virus-like Particles Containing Multiple M2 Extracellular Domains Confer Improved Cross-protection Against Various Subtypes of Influenza Virus

PubMed Central

Kim, Min-Chul; Song, Jae-Min; O, Eunju; Kwon, Young-Man; Lee, Youn-Jeong; Compans, Richard W; Kang, Sang-Moo

2013-01-01

The extracellular domain of M2 (M2e), a small ion channel membrane protein, is well conserved among different human influenza A virus strains. To improve the protective efficacy of M2e vaccines, we genetically engineered a tandem repeat of M2e epitope sequences (M2e5x) of human, swine, and avian origin influenza A viruses, which was expressed in a membrane-anchored form and incorporated in virus-like particles (VLPs). The M2e5x protein with the transmembrane domain of hemagglutinin (HA) was effectively incorporated into VLPs at a several 100-fold higher level than that on influenza virions. Intramuscular immunization with M2e5x VLP vaccines was highly effective in inducing M2e-specific antibodies reactive to different influenza viruses, mucosal and systemic immune responses, and cross-protection regardless of influenza virus subtypes in the absence of adjuvant. Importantly, immune sera were found to be sufficient for conferring protection in naive mice, which was long-lived and cross-protective. Thus, molecular designing and presenting M2e immunogens on VLPs provide a promising platform for developing universal influenza vaccines without using adjuvants. PMID:23247101

Epitope-focused peptide immunogens in human use adjuvants protect rabbits from experimental inhalation anthrax.

PubMed

Oscherwitz, Jon; Feldman, Daniel; Yu, Fen; Cease, Kemp B

2015-01-09

Anthrax represents a formidable bioterrorism threat for which new, optimized vaccines are required. We previously demonstrated that epitope-focused multiple antigenic peptides or a recombinant protein in Freund's adjuvant can elicit Ab against the loop neutralizing determinant (LND), a cryptic linear neutralizing epitope in the 2ß2-2ß3 loop of protective antigen from Bacillus anthracis, which mediated protection of rabbits from inhalation challenge with B. anthracis Ames strain. However, demonstration of efficacy using human-use adjuvants is required before proceeding with further development of an LND vaccine for testing in non-human primates and humans. To optimize the LND immunogen, we first evaluated the protective efficacy and immune correlates associated with immunization of rabbits with mixtures containing two molecular variants of multiple antigenic peptides in Freunds adjuvant, termed BT-LND(2) and TB-LND(2). TB-LND(2) was then further evaluated for protective efficacy in rabbits employing human-use adjuvants. Immunization of rabbits with TB-LND(2) in human-use adjuvants elicited protection from Ames strain spore challenge which was statistically indistinguishable from that elicited through immunization with protective antigen. All TB-LND(2) rabbits with any detectable serum neutralization prior to challenge were protected from aerosolized spore exposure. Remarkably, rabbits immunized with TB-LND(2) in Alhydrogel/CpG had significant anamnestic increases in post-challenge LND-specific Ab and neutralization titers despite little evidence of spore germination in these rabbits. An LND-specific epitope-focused vaccine may complement PA-based vaccines and may represent a complementary stand-alone vaccine for anthrax. Copyright © 2014 Elsevier Ltd. All rights reserved.

A molecular dynamics study of loop fluctuation in human papillomavirus type 16 virus-like particles: a possible indicator of immunogenicity.

PubMed

Joshi, Harshad; Cheluvaraja, Srinath; Somogyi, Endre; Brown, Darron R; Ortoleva, Peter

2011-11-28

Immunogenicity varies between the human papillomavirus (HPV) L1 monomer assemblies of various sizes (e.g., monomers, pentamers or whole capsids). The hypothesis that this can be attributed to the intensity of fluctuations of important loops containing neutralizing epitopes for the various assemblies is proposed for HPV L1 assemblies. Molecular dynamics simulations were utilized to begin testing this hypothesis. Fluctuations of loops that contain critical neutralizing epitopes (especially FG loop) were quantified via root-mean-square fluctuation and features in the frequency spectrum of dynamic changes in loop conformation. If this fluctuation-immunogenicity hypothesis is a universal aspect of immunogenicity (i.e., immune system recognition of an epitope within a loop is more reliable when it is presented via a more stable delivery structure), then fluctuation measures can serve as one predictor of immunogenicity as part of a computer-aided vaccine design strategy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Reduced T cell response to beta-lactoglobulin by conjugation with acidic oligosaccharides.

PubMed

Yoshida, Tadashi; Sasahara, Yoshimasa; Miyakawa, Shunpei; Hattori, Makoto

2005-08-24

We have previously reported that the conjugation of beta-lactoglobulin (beta-LG) with alginic acid oligosaccharide (ALGO) and phosphoryl oligosaccharides reduced the immunogenicity of beta-LG. In addition, those conjugates showed higher thermal stability and improved emulsifying properties than those of native beta-LG. We examine in this study the effect of conjugation on the T cell response. Our results demonstrate that the T cell response was reduced when mice were immunized with the conjugates. The findings obtained from an experiment using overlapping synthetic peptides show that novel epitopes were not generated by conjugation. One of the mechanisms for the reduced T cell response to the conjugates was found to be the reduced susceptibility of the conjugates to processing enzymes for antigen presentation. We further clarify that the beta-LG-ALGO conjugate modulated the immune response to Th1 dominance. We consider that this property of the beta-LG-ALGO conjugate would be effective for preventing food allergy as well as by its reduced immunogenicity. Our observations indicate that the method used in this study could be applied to various protein allergens to achieve reduced allergenicity with multiple improvements in their properties.

A randomised, double-blind, controlled trial of a killed L. major vaccine plus BCG against zoonotic cutaneous leishmaniasis in Iran.

PubMed

Momeni, A Z; Jalayer, T; Emamjomeh, M; Khamesipour, A; Zicker, F; Ghassemi, R L; Dowlati, Y; Sharifi, I; Aminjavaheri, M; Shafiei, A; Alimohammadian, M H; Hashemi-Fesharki, R; Nasseri, K; Godal, T; Smith, P G; Modabber, F

1999-02-05

Safety and efficacy of killed (autoclaved) L. major promastigotes, ALM, mixed with BCG against zoonotic cutaneous leishmaniasis was tested in healthy volunteers (n = 2453) in a randomized double blind trial vs. BCG as control. Side-effects were similar in both groups but tended to be slightly more frequent and prolonged in the ALM + BCG group. Leishmanin skin test conversion (induration > or =5 mm) was significantly greater in the ALM + BCG than in the BCG group (36.2% vs. 7.9% on day-80 and 33% vs. 19%, after 1 year, respectively). Cumulative incidence rates for 2 years, were similar in both groups (18.0% vs. 18.5%). However, LST responders on day 80 (> or =5 mm) had a significantly lower incidence (35%) of CL during the first year than non-responders. A single dose of ALM + BCG is not sufficiently immunogenic to provide a measurable response when compared to BCG alone. A single dose of this vaccine has been shown to be safe with no evidence of an exacerbating response following natural infection; hence, multiple doses or other adjuvants should be considered to increase its immunogenicity.

Can dendritic cells improve whole cancer cell vaccines based on immunogenically killed cancer cells?

PubMed Central

Cicchelero, Laetitia; Denies, Sofie; Devriendt, Bert; de Rooster, Hilde; Sanders, Niek N

2015-01-01

Immunogenic cell death (ICD) offers interesting opportunities in cancer cell (CC) vaccine manufacture, as it increases the immunogenicity of the dead CC. Furthermore, fusion of CCs with dendritic cells (DCs) is considered a superior method for generating whole CC vaccines. Therefore, in this work, we determined in naive mice whether immunogenically killed CCs per se (CC vaccine) elicit an antitumoral immune response different from the response observed when immunogenically killed CCs are associated with DCs through fusion (fusion vaccine) or through co-incubation (co-incubation vaccine). After tumor inoculation, the type of immune response in the prophylactically vaccinated mice differed between the groups. In more detail, fusion vaccines elicited a humoral anticancer response, whereas the co-incubation and CC vaccine mainly induced a cellular response. Despite these differences, all three approaches offered a prophylactic protection against tumor development in the murine mammary carcinoma model. In summary, it can be concluded that whole CC vaccines based on immunogenically killed CCs may not necessarily require association with DCs to elicit a protective anticancer immune response. If this finding can be endorsed in other cancer models, the manufacture of CC vaccines would greatly benefit from this new insight, as production of DC-based vaccines is laborious, time-consuming and expensive. PMID:26587315

Determinants of immunogenic response to protein therapeutics.

PubMed

Singh, Satish K; Cousens, Leslie P; Alvarez, David; Mahajan, Pramod B

2012-09-01

Protein therapeutics occupy a very significant position in the biopharmaceutical market. In addition to the preclinical, clinical and post marketing challenges common to other drugs, unwanted immunogenicity is known to affect efficacy and/or safety of most biotherapeutics. A standard set of immunogenicity risk factors are routinely used to inform monitoring strategies in clinical studies. A number of in-silico, in vivo and in vitro approaches have also been employed to predict immunogenicity of biotherapeutics, but with limited success. Emerging data also indicates the role of immune tolerance mechanisms and impact of several product-related factors on modulating host immune responses. Thus, a comprehensive discussion of the impact of innate and adaptive mechanisms and molecules involved in induction of host immune responses on immunogenicity of protein therapeutics is needed. A detailed understanding of these issues is essential in order to fully exploit the therapeutic potential of this class of drugs. This Roundtable Session was designed to provide a common platform for discussing basic immunobiological and pharmacological issues related to the role of biotherapeutic-associated risk factors, as well as host immune system in immunogenicity against protein therapeutics. The session included overview presentations from three speakers, followed by a panel discussion with audience participation. Copyright © 2012. Published by Elsevier Ltd.. All rights reserved.

Identification of immunogenic polypeptides from a Mycoplasma hyopneumoniae genome library by phage display.

PubMed

Kügler, Jonas; Nieswandt, Simone; Gerlach, Gerald F; Meens, Jochen; Schirrmann, Thomas; Hust, Michael

2008-09-01

The identification of immunogenic polypeptides of pathogens is helpful for the development of diagnostic assays and therapeutic applications like vaccines. Routinely, these proteins are identified by two-dimensional polyacrylamide gel electrophoresis and Western blot using convalescent serum, followed by mass spectrometry. This technology, however, is limited, because low or differentially expressed proteins, e.g. dependent on pathogen-host interaction, cannot be identified. In this work, we developed and improved a M13 genomic phage display-based method for the selection of immunogenic polypeptides of Mycoplasma hyopneumoniae, a pathogen causing porcine enzootic pneumonia. The fragmented genome of M. hyopneumoniae was cloned into a phage display vector, and the genomic library was packaged using the helperphage Hyperphage to enrich open reading frames (ORFs). Afterwards, the phage display library was screened by panning using convalescent serum. The analysis of individual phage clones resulted in the identification of five genes encoding immunogenic proteins, only two of which had been previously identified and described as immunogenic. This M13 genomic phage display, directly combining ORF enrichment and the presentation of the corresponding polypeptide on the phage surface, complements proteome-based methods for the identification of immunogenic polypeptides and is particularly well suited for the use in mycoplasma species.

Rhizobium etli asparaginase II

PubMed Central

Huerta-Saquero, Alejandro; Evangelista-Martínez, Zahaed; Moreno-Enriquez, Angélica; Perez-Rueda, Ernesto

2013-01-01

Bacterial l-asparaginase has been a universal component of therapies for childhood acute lymphoblastic leukemia since the 1970s. Two principal enzymes derived from Escherichia coli and Erwinia chrysanthemi are the only options clinically approved to date. We recently reported a study of recombinant l-asparaginase (AnsA) from Rhizobium etli and described an increasing type of AnsA family members. Sequence analysis revealed four conserved motifs with notable differences with respect to the conserved regions of amino acid sequences of type I and type II l-asparaginases, particularly in comparison with therapeutic enzymes from E. coli and E. chrysanthemi. These differences suggested a distinct immunological specificity. Here, we report an in silico analysis that revealed immunogenic determinants of AnsA. Also, we used an extensive approach to compare the crystal structures of E. coli and E. chrysantemi asparaginases with a computational model of AnsA and identified immunogenic epitopes. A three-dimensional model of AsnA revealed, as expected based on sequence dissimilarities, completely different folding and different immunogenic epitopes. This approach could be very useful in transcending the problem of immunogenicity in two major ways: by chemical modifications of epitopes to reduce drug immunogenicity, and by site-directed mutagenesis of amino acid residues to diminish immunogenicity without reduction of enzymatic activity. PMID:22895060

Rhizobium etli asparaginase II: an alternative for acute lymphoblastic leukemia (ALL) treatment.

PubMed

Huerta-Saquero, Alejandro; Evangelista-Martínez, Zahaed; Moreno-Enriquez, Angélica; Perez-Rueda, Ernesto

2013-01-01

Bacterial L-asparaginase has been a universal component of therapies for childhood acute lymphoblastic leukemia since the 1970s. Two principal enzymes derived from Escherichia coli and Erwinia chrysanthemi are the only options clinically approved to date. We recently reported a study of recombinant L-asparaginase (AnsA) from Rhizobium etli and described an increasing type of AnsA family members. Sequence analysis revealed four conserved motifs with notable differences with respect to the conserved regions of amino acid sequences of type I and type II L-asparaginases, particularly in comparison with therapeutic enzymes from E. coli and E. chrysanthemi. These differences suggested a distinct immunological specificity. Here, we report an in silico analysis that revealed immunogenic determinants of AnsA. Also, we used an extensive approach to compare the crystal structures of E. coli and E. chrysantemi asparaginases with a computational model of AnsA and identified immunogenic epitopes. A three-dimensional model of AsnA revealed, as expected based on sequence dissimilarities, completely different folding and different immunogenic epitopes. This approach could be very useful in transcending the problem of immunogenicity in two major ways: by chemical modifications of epitopes to reduce drug immunogenicity, and by site-directed mutagenesis of amino acid residues to diminish immunogenicity without reduction of enzymatic activity.

Mutual enhancement of IL-2 and IL-7 on DNA vaccine immunogenicity mainly involves regulations on their receptor expression and receptor-expressing lymphocyte generation.

PubMed

Zhang, Yonghong; Liang, Shuang; Li, Xiujin; Wang, Liyue; Zhang, Jianlou; Xu, Jian; Huo, Shanshan; Cao, Xuebin; Zhong, Zhenyu; Zhong, Fei

2015-07-09

Our previous study showed that IL-2 and IL-7 could mutually enhance the immunogenicity of canine parvovirus VP2 DNA vaccine, although the underlying mechanism remained unknown. Here, we used the OVA gene as a DNA vaccine in a mouse model to test their enhancement on DNA vaccine immunogenicity and to explore the molecular mechanism. Results showed that both IL-2 and IL-7 genes significantly increased the immunogenicity of OVA DNA vaccine in mice. Co-administration of IL-2 and IL-7 genes with OVA DNA significantly increased OVA-specific antibody titers, T cell proliferation and IFN-γ production compared with IL-2 or IL-7 alone, confirming that IL-2 and IL-7 mutually enhanced DNA vaccine immunogenicity. Mechanistically, we have shown that IL-2 significantly stimulated generation of IL-7 receptor-expressing lymphocytes, and that IL-7 significantly induced IL-2 receptor expression. These results contribute to an explanation of the mechanism of the mutual effects of IL-2 and IL-7 on enhancing DNA vaccine immunogenicity and provided a basis for further investigation on their mutual effects on adjuvant activity and immune regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antitumor effects of a tumor cell vaccine expressing a membrane-bound form of the IL-12 p35 subunit.

PubMed

Lim, Ho Yong; Ju, Hee Young; Chung, Hee-Yong; Kim, Young Sang

2010-08-15

We investigated whether expression of the IL-12 p35 subunit in membrane-bound form in tumor cells enhanced their immunogenicity. Since p35 is only secreted when associated with the IL-12 p40 subunit, we generated tumor cells expressing membrane-bound forms of p35 and p40 as chimeras with the transmembrane/cytoplasmic region of TNFα (mbIL-12p35 and mbIL-12p40). The relevant vectors were transfected into MethA fibrosarcoma cells, and mbIL-12p35 or mbIL-12p40-expressing tumor clones were isolated and their ability to induce antitumor immunity studied. Cells of the mbIL-12p35 tumor clone induced CD69 expression and IFNγ production in purified CD8(+) T cells in vitro, and their in vivo tumorigenicity was reduced. Cells of the mbIL-12p40 tumor clone failed to show either of these activities. Mice that had rejected cells of the mbIL-12p35 tumor clone possessed systemic antitumor immunity to wild type tumor cells. The growth rate of mbIL-12p35 tumor cells was greater in CD8(+) T cell-depleted mice than in CD4(+) T-cell- and NK cell-depleted mice or normal mice, suggesting that CD8(+) T cells were mainly responsible for the antitumor immunity. These results indicate that expression of mbIL-12p35 on tumor cells enhances their immunogenicity by increasing their ability to activate CD8(+) T cells, possibly by direct priming.

Factors influencing preclinical in vivo evaluation of mumps vaccine strain immunogenicity

PubMed Central

Halassy, B; Kurtović, T; Brgles, M; Lang Balija, M; Forčić, D

2015-01-01

Immunogenicity testing in animals is a necessary preclinical assay for demonstration of vaccine efficacy the results of which are often the basis for the decision whether to proceed or withdraw the further development of the novel vaccine candidate. However, in vivo assays are rarely, if at all, optimized and validated. Here we clearly demonstrate the importance of in vivo assay (mumps virus immunogenicity testing in guinea pigs) optimization for gaining reliable results and the suitability of Fractional factorial design of experiments (DoE) for such a purpose. By the use of DoE with resolution IV (2IV(4-1)) we clearly revealed that the parameters significantly increasing assay sensitivity were interval between animal immunizations followed by the body weight of experimental animals. The quantity (0 versus 2%) of the stabilizer (fetal bovine serum, FBS) in the sample was shown as non-influencing parameter in DoE setup. However, the separate experiment investigating only the FBS influence, and performed under other parameters optimally set, showed that FBS also influences the results of immunogenicity assay. Such finding indicated that (a) factors with strong influence on the measured outcome can hide the effects of parameters with modest/low influence and (b) the matrix of mumps virus samples to be compared for immunogenicity must be identical for reliable virus immunogenicity comparison. Finally the 3 mumps vaccine strains widely used for decades in the licensed vaccines were for the first time compared in an animal model, and results obtained were in line with their reported immunogenicity in human population supporting the predictive power of the optimized in vivo assay. PMID:26376015

Factors influencing preclinical in vivo evaluation of mumps vaccine strain immunogenicity.

PubMed

Halassy, B; Kurtović, T; Brgles, M; Lang Balija, M; Forčić, D

2015-01-01

Immunogenicity testing in animals is a necessary preclinical assay for demonstration of vaccine efficacy the results of which are often the basis for the decision whether to proceed or withdraw the further development of the novel vaccine candidate. However, in vivo assays are rarely, if at all, optimized and validated. Here we clearly demonstrate the importance of in vivo assay (mumps virus immunogenicity testing in guinea pigs) optimization for gaining reliable results and the suitability of Fractional factorial design of experiments (DoE) for such a purpose. By the use of DoE with resolution IV (2IV((4-1))) we clearly revealed that the parameters significantly increasing assay sensitivity were interval between animal immunizations followed by the body weight of experimental animals. The quantity (0 versus 2%) of the stabilizer (fetal bovine serum, FBS) in the sample was shown as non-influencing parameter in DoE setup. However, the separate experiment investigating only the FBS influence, and performed under other parameters optimally set, showed that FBS also influences the results of immunogenicity assay. Such finding indicated that (a) factors with strong influence on the measured outcome can hide the effects of parameters with modest/low influence and (b) the matrix of mumps virus samples to be compared for immunogenicity must be identical for reliable virus immunogenicity comparison. Finally the 3 mumps vaccine strains widely used for decades in the licensed vaccines were for the first time compared in an animal model, and results obtained were in line with their reported immunogenicity in human population supporting the predictive power of the optimized in vivo assay.

Development of a strategy and computational application to select candidate protein analogues with reduced HLA binding and immunogenicity.

PubMed

Dhanda, Sandeep Kumar; Grifoni, Alba; Pham, John; Vaughan, Kerrie; Sidney, John; Peters, Bjoern; Sette, Alessandro

2018-01-01

Unwanted immune responses against protein therapeutics can reduce efficacy or lead to adverse reactions. T-cell responses are key in the development of such responses, and are directed against immunodominant regions within the protein sequence, often associated with binding to several allelic variants of HLA class II molecules (promiscuous binders). Herein, we report a novel computational strategy to predict 'de-immunized' peptides, based on previous studies of erythropoietin protein immunogenicity. This algorithm (or method) first predicts promiscuous binding regions within the target protein sequence and then identifies residue substitutions predicted to reduce HLA binding. Further, this method anticipates the effect of any given substitution on flanking peptides, thereby circumventing the creation of nascent HLA-binding regions. As a proof-of-principle, the algorithm was applied to Vatreptacog α, an engineered Factor VII molecule associated with unintended immunogenicity. The algorithm correctly predicted the two immunogenic peptides containing the engineered residues. As a further validation, we selected and evaluated the immunogenicity of seven substitutions predicted to simultaneously reduce HLA binding for both peptides, five control substitutions with no predicted reduction in HLA-binding capacity, and additional flanking region controls. In vitro immunogenicity was detected in 21·4% of the cultures of peptides predicted to have reduced HLA binding and 11·4% of the flanking regions, compared with 46% for the cultures of the peptides predicted to be immunogenic. This method has been implemented as an interactive application, freely available online at http://tools.iedb.org/deimmunization/. © 2017 John Wiley & Sons Ltd.

[Treatment perspectives].

PubMed

Garnier-Lengliné, H; Malamut, G; Cerf-Bensussan, N; Ruemmele, F M

2013-06-01

Celiac disease (CD) is a chronic inflammatory enteropathy caused by the ingestion of gluten. A safe and efficient but unpleasant treatment exists for CD in form of a strict gluten-free diet. Thus, there is a need for new treatment strategies, which are based on the improved and advanced understanding of the pathophysiology of CD. The first strategy consists in reducing or even eliminating major antigenic motifs in gluten, responsible for the inflammatory reaction. The use of less immunogenic wheat was suggested but this seems rather difficult to realize. However, a complete digestion of the immunogenic parts of gluten looks very promising. This can be obtained by the use of polymers, capable to sequester gluten proteins or even better via the exogenous administration of propyl-endopeptidases, with two different enzymes under development. Another approach could be the use of inhibitors of tissue transglutaminase, a strategy which is under clinical investigation. Alternatively, inhibition of the site of liaison of immunostimulatory peptides with HLA molecules was suggested and is also under investigation in vivo. For patients suffering from refractory sprue, the inhibition of IL15 might be of therapeutic interest with the hope to improve the fatal outcome of many of these patients. However, the ultimate treatment approach is in form of prevention and the role of infectious agents, such as Rotavirus, in disease onset has to be considered. Copyright © 2011. Published by Elsevier SAS.

Recombinant H7 hemagglutinin forms subviral particles that protect mice and ferrets from challenge with H7N9 influenza virus

PubMed Central

Pushko, Peter; Pujanauski, Lindsey M.; Sun, Xiangjie; Pearce, Melissa; Hidajat, Rachmat; Kort, Thomas; Schwartzman, Louis M.; Tretyakova, Irina; Chunqing, Liu; Taubenberger, Jeffery K.; Tumpey, Terrence M.

2015-01-01

A novel avian-origin influenza A H7N9 virus emerged in China in 2013 and continues to cause sporadic human infections with mortality rates approaching 35%. Currently there are no approved human vaccines for H7N9 virus. Recombinant approaches including hemagglutinin (HA) and virus-like particles (VLPs) have resulted in experimental vaccines with advantageous safety and manufacturing characteristics. While high immunogenicity of VLP vaccines has been attributed to the native conformation of HA arranged in the regular repeated patterns within virus-like structures, there is limited data regarding molecular organization of HA within recombinant HA vaccine preparations. In this study, the full-length recombinant H7 protein (rH7) of A/Anhui/1/2013 (H7N9) virus was expressed in Sf9 cells. We showed that purified full-length rH7 retained functional ability to agglutinate red blood cells and formed oligomeric pleomorphic subviral particles (SVPs) of ~20 nm in diameter composed of approximately 10 HA0 molecules. No significant quantities of free monomeric HA0 were observed in rH7 preparation by size exclusion chromatography. Immunogenicity and protective efficacy of rH7 SVPs was confirmed in the mouse and ferret challenge models suggesting that SVPs can be used for vaccination against H7N9 virus. PMID:26207590

Virus-based nanoparticles as platform technologies for modern vaccines

PubMed Central

Lee, Karin L.; Twyman, Richard M.; Fiering, Steven

2017-01-01

Nanoscale engineering is revolutionizing the development of vaccines and immunotherapies. Viruses have played a key role in this field because they can function as prefabricated nanoscaffolds with unique properties that are easy to modify. Viruses are immunogenic through multiple pathways, and antigens displayed naturally or by engineering on the surface can be used to create vaccines against the cognate virus, other pathogens, specific molecules or cellular targets such as tumors. This review focuses on the development of virus-based nanoparticle systems as vaccines indicated for the prevention or treatment of infectious diseases, chronic diseases, cancer, and addiction. PMID:26782096

[Research progress on ebola virus glycoprotein].

PubMed

Ding, Guo-Yong; Wang, Zhi-Yu; Gao, Lu; Jiang, Bao-Fa

2013-03-01

Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans and there are no effective therapeutic or prophylactic treatments available. The glycoprotein (GP) of EBOV is a transmembrane envelope protein known to play multiple functions including virus attachment and entry, cell rounding and cytotoxicity, down-regulation of host surface proteins, and enhancement of virus assembly and budding. GP is the primary target of protective immunity and the key target for developing neutralizing antibodies. In this paper, the research progress on genetic structure, pathogenesis and immunogenicity of EBOV GP in the last 5 years is reviewed.

Production of pseudoinfectious yellow fever virus with a two-component genome.

PubMed

Shustov, Alexandr V; Mason, Peter W; Frolov, Ilya

2007-11-01

Application of genetically modified, deficient-in-replication flaviviruses that are incapable of developing productive, spreading infection is a promising means of designing safe and effective vaccines. Here we describe a two-component genome yellow fever virus (YFV) replication system in which each of the genomes encodes complete sets of nonstructural proteins that form the replication complex but expresses either only capsid or prM/E instead of the entire structural polyprotein. Upon delivery to the same cell, these genomes produce together all of the viral structural proteins, and cells release a combination of virions with both types of genomes packaged into separate particles. In tissue culture, this modified YFV can be further passaged at an escalating scale by using a high multiplicity of infection (MOI). However, at a low MOI, only one of the genomes is delivered into the cells, and infection cannot spread. The replicating prM/E-encoding genome produces extracellular E protein in the form of secreted subviral particles that are known to be an effective immunogen. The presented strategy of developing viruses defective in replication might be applied to other flaviviruses, and these two-component genome viruses can be useful for diagnostic or vaccine applications, including the delivery and expression of heterologous genes. In addition, the achieved separation of the capsid-coding sequence and the cyclization signal in the YFV genome provides a new means for studying the mechanism of the flavivirus packaging process.

Pre-clinical antigenicity studies of an innovative multivalent vaccine for human visceral leishmaniasis.

PubMed

Cecílio, Pedro; Pérez-Cabezas, Begoña; Fernández, Laura; Moreno, Javier; Carrillo, Eugenia; Requena, José M; Fichera, Epifanio; Reed, Steven G; Coler, Rhea N; Kamhawi, Shaden; Oliveira, Fabiano; Valenzuela, Jesus G; Gradoni, Luigi; Glueck, Reinhard; Gupta, Gaurav; Cordeiro-da-Silva, Anabela

2017-11-01

The notion that previous infection by Leishmania spp. in endemic areas leads to robust anti-Leishmania immunity, supports vaccination as a potentially effective approach to prevent disease development. Nevertheless, to date there is no vaccine available for human leishmaniasis. We optimized and assessed in vivo the safety and immunogenicity of an innovative vaccine candidate against human visceral leishmaniasis (VL), consisting of Virus-Like Particles (VLP) loaded with three different recombinant proteins (LJL143 from Lutzomyia longipalpis saliva as the vector-derived (VD) component, and KMP11 and LeishF3+, as parasite-derived (PD) antigens) and adjuvanted with GLA-SE, a TLR4 agonist. No apparent adverse reactions were observed during the experimental time-frame, which together with the normal hematological parameters detected seems to point to the safety of the formulation. Furthermore, measurements of antigen-specific cellular and humoral responses, generally higher in immunized versus control groups, confirmed the immunogenicity of the vaccine formulation. Interestingly, the immune responses against the VD protein were reproducibly more robust than those elicited against leishmanial antigens, and were apparently not caused by immunodominance of the VD antigen. Remarkably, priming with the VD protein alone and boosting with the complete vaccine candidate contributed towards an increase of the immune responses to the PD antigens, assessed in the form of increased ex vivo CD4+ and CD8+ T cell proliferation against both the PD antigens and total Leishmania antigen (TLA). Overall, our immunogenicity data indicate that this innovative vaccine formulation represents a promising anti-Leishmania vaccine whose efficacy deserves to be tested in the context of the "natural infection".

Translating the Immunogenicity of Prime-boost Immunization With ChAd63 and MVA ME-TRAP From Malaria Naive to Malaria-endemic Populations

PubMed Central

Kimani, Domtila; Jagne, Ya Jankey; Cox, Momodou; Kimani, Eva; Bliss, Carly M; Gitau, Evelyn; Ogwang, Caroline; Afolabi, Muhammed O; Bowyer, Georgina; Collins, Katharine A; Edwards, Nick; Hodgson, Susanne H; Duncan, Christopher J A; Spencer, Alexandra J; Knight, Miguel G; Drammeh, Abdoulie; Anagnostou, Nicholas A; Berrie, Eleanor; Moyle, Sarah; Gilbert, Sarah C; Soipei, Peninah; Okebe, Joseph; Colloca, Stefano; Cortese, Riccardo; Viebig, Nicola K; Roberts, Rachel; Lawrie, Alison M; Nicosia, Alfredo; Imoukhuede, Egeruan B; Bejon, Philip; Chilengi, Roma; Bojang, Kalifa; Flanagan, Katie L; Hill, Adrian V S; Urban, Britta C; Ewer, Katie J

2014-01-01

To induce a deployable level of efficacy, a successful malaria vaccine would likely benefit from both potent cellular and humoral immunity. These requirements are met by a heterologous prime-boost immunization strategy employing a chimpanzee adenovirus vector followed by modified vaccinia Ankara (MVA), both encoding the pre-erythrocytic malaria antigen ME-thrombospondin-related adhesive protein (TRAP), with high immunogenicity and significant efficacy in UK adults. We undertook two phase 1b open-label studies in adults in Kenya and The Gambia in areas of similar seasonal malaria transmission dynamics and have previously reported safety and basic immunogenicity data. We now report flow cytometry and additional interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) data characterizing pre-existing and induced cellular immunity as well as anti-TRAP IgG responses. T-cell responses induced by vaccination averaged 1,254 spot-forming cells (SFC) per million peripheral blood mononuclear cells (PBMC) across both trials and flow cytometry revealed cytokine production from both CD4+ and CD8+ T cells with the frequency of CD8+ IFN-γ-secreting monofunctional T cells (previously shown to associate with vaccine efficacy) particularly high in Kenyan adults. Immunization with ChAd63 and MVA ME-TRAP induced strong cellular and humoral immune responses in adults living in two malaria-endemic regions of Africa. This prime-boost approach targeting the pre-erythrocytic stage of the malaria life-cycle is now being assessed for efficacy in a target population. PMID:24930599

Adult and cord blood endothelial progenitor cells have different gene expression profiles and immunogenic potential.

PubMed

Nuzzolo, Eugenia R; Capodimonti, Sara; Martini, Maurizio; Iachininoto, Maria G; Bianchi, Maria; Cocomazzi, Alessandra; Zini, Gina; Leone, Giuseppe; Larocca, Luigi M; Teofili, Luciana

2014-01-01

Endothelial colony-forming cells (ECFC) are endowed with vascular regenerative ability in vivo and in vitro. In this study we compared the genotypic profile and the immunogenic potential of adult and cord blood ECFC, in order to explore the feasibility of using them as a cell therapy product. ECFC were obtained from cord blood samples not suitable for haematopoietic stem cell transplantation and from adult healthy blood donors after informed consent. Genotypes were analysed by commercially available microarray assays and results were confirmed by real-time polymerase chain reaction analysis. HLA antigen expression was evaluated by flow-cytometry. Immunogenic capacity was investigated by evaluating the activation of allogeneic lymphocytes and monocytes in co-cultures with ECFC. Microarray assays revealed that the genetic profile of cord blood and adult ECFC differed in about 20% of examined genes. We found that cord blood ECFC were characterised by lower pro-inflammatory and pro-thrombotic gene expression as compared to adult ECFC. Furthermore, whereas cord blood and adult ECFCs expressed similar amount of HLA molecules both at baseline and after incubation with γ-interferon, cord blood ECFC elicited a weaker expression of pro-inflammatory cytokine genes. Finally, we observed no differences in the amount of HLA antigens expressed among cord blood ECFC, adult ECFC and mesenchymal cells. Our observations suggest that cord blood ECFC have a lower pro-inflammatory and pro-thrombotic profile than adult ECFC. These preliminary data offer level-headed evidence to use cord blood ECFC as a cell therapy product in vascular diseases.

Anti-EBOV GP IgGs Lacking α1-3-Galactose and Neu5Gc Prolong Survival and Decrease Blood Viral Load in EBOV-Infected Guinea Pigs

PubMed Central

Reynard, Olivier; Jacquot, Frédéric; Evanno, Gwénaëlle; Mai, Hoa Le; Martinet, Bernard; Duvaux, Odile; Bach, Jean-Marie; Conchon, Sophie; Judor, Jean-Paul; Perota, Andrea; Lagutina, Irina; Duchi, Roberto; Lazzari, Giovanna; Le Berre, Ludmilla; Perreault, Hélène; Lheriteau, Elsa; Raoul, Hervé; Volchkov, Viktor; Galli, Cesare; Soulillou, Jean-Paul

2016-01-01

Polyclonal xenogenic IgGs, although having been used in the prevention and cure of severe infectious diseases, are highly immunogenic, which may restrict their usage in new applications such as Ebola hemorrhagic fever. IgG glycans display powerful xenogeneic antigens in humans, for example α1–3 Galactose and the glycolyl form of neuraminic acid Neu5Gc, and IgGs deprived of these key sugar epitopes may represent an advantage for passive immunotherapy. In this paper, we explored whether low immunogenicity IgGs had a protective effect on a guinea pig model of Ebola virus (EBOV) infection. For this purpose, a double knock-out pig lacking α1–3 Galactose and Neu5Gc was immunized against virus-like particles displaying surface EBOV glycoprotein GP. Following purification from serum, hyper-immune polyclonal IgGs were obtained, exhibiting an anti-EBOV GP titer of 1:100,000 and a virus neutralizing titer of 1:100. Guinea pigs were injected intramuscularly with purified IgGs on day 0 and day 3 post-EBOV infection. Compared to control animals treated with IgGs from non-immunized double KO pigs, the anti-EBOV IgGs-treated animals exhibited a significantly prolonged survival and a decreased virus load in blood on day 3. The data obtained indicated that IgGs lacking α1–3 Galactose and Neu5Gc, two highly immunogenic epitopes in humans, have a protective effect upon EBOV infection. PMID:27280712

[Results of radioiodine therapy in different forms of hyperthyroidism in relation to the planned dosage].

PubMed

Moser, E

1992-07-01

The aim of this study was to assess the efficacy of radioiodine therapy (131J) in a large group (n = 925) of hyperthyroid patients treated at two major departments of nuclear medicine (Freiburg, abbr. FR, and Munich, abbr. M). 761 patients suffered from non-immunogenic hyperthyroidism (Plummer's disease) and the remaining 164 patients from immunogenic hyperthyroidism (Graves' disease). In these cases, radioiodine therapy using doses between 60 and 80 Gy proved ineffective, FR (80 Gy) recording 28% success and M (60 Gy) 54%. A dose of 150 Gy, however, is successful in more than 80% of the cases: FR 81%, M86%. However, the incidence rate of hypothyroidism increases consecutively with 150 Gy: FR 49%, M 62%. In patients suffering from Plummer's disease, the solitary autonomous nodule can be eliminated by radioiodine therapy (400 Gy) with a high rate of success (95%); the same applies to multinodular autonomous adenomas. The therapeutic concept applying a dose of 400 Gy to the total functional autonomous tissue (delineated by ultrasound) yields slightly better results (95%) than 150 Gy applied to thyroid gland (M88%, FR82%). This dosimetric compromise is a practicable alternative which is tolerably successful. In patients suffering from disseminated non-immunogenic hyperthyroidism, a dose of 150 Gy applied to the entire organ succeeds in 85% of the cases. The rate of hypothyroidism resulting from these dose recommendations is the lesser evil compared to residual or recurrent hyperthyroidism, since hypothyroid patients can be treated without any problem with thyroid hormones.

Differences in components at delayed-type hypersensitivity reaction sites in mice immunized with either a protective or a nonprotective immunogen of Cryptococcus neoformans.

PubMed

Nichols, Kasie L; Bauman, Sean K; Schafer, Fredda B; Murphy, Juneann W

2002-02-01

Cell-mediated immunity is the major protective mechanism against Cryptococcus neoformans. Delayed swelling reactions, i.e., delayed-type hypersensitivity (DTH), in response to an intradermal injection of specific antigen are used as a means of detecting a cell-mediated immune (CMI) response to the antigen. We have found previously that the presence of an anticryptococcal DTH response in mice is not always indicative of protection against a cryptococcal infection. Using one immunogen that induces a protective anticryptococcal CMI response and one that induces a nonprotective response, we have shown that mice immunized with the protective immunogen undergo a classical DTH response characterized by mononuclear cell and neutrophil infiltrates and the presence of gamma interferon and NO. In contrast, immunization with the nonprotective immunogen results in an influx of primarily neutrophils and production of tumor necrosis factor alpha (TNF-alpha) at the DTH reaction site. Even when the anticryptococcal DTH response was augmented by blocking the down-regulator, CTLA-4 (CD152), on T cells in the mice given the nonprotective immunogen, the main leukocyte population infiltrating the DTH reaction site is the neutrophil. Although TNF-alpha is increased at the DTH reaction site in mice immunized with the nonprotective immunogen, it is unlikely that TNF-alpha activates the neutrophils, because the density of TNF receptors on the neutrophils is reduced below control levels. Uncoupling of DTH reactivity and protection has been demonstrated in other infectious-disease models; however, the mechanisms differ from our model. These findings stress the importance of defining the cascade of events occurring in response to various immunogens and establishing the relationships between protection and DTH reactions.

Advance in Anti-tumor Mechanisms of Shikonin, Alkannin and their Derivatives.

PubMed

Zhang, Xu; Cui, Jia-Hua; Meng, Qing-Qing; Li, Shao-Shun; Zhou, Wen; Xiao, Sui

2018-01-01

Shikonin, alkannin and their derivatives, the main ingredient of Lithospermum erythrorhizon and Arnebia euchroma (Royle) Johnst native to Inner Mongolian and Northwest of China respectively, hold promising potentials for antitumor effects via multiple-target mechanisms. This review will emphasize the importance of their antitumor activity in apoptosis, necroptosis and immunogenic cell death, and expound the relationship of their antitumor activity and naphthoquinone scaffold that could generate ROS and alkylating agent. Meanwhile, the antitumor mechanisms of naturally-occurring shikonin, alkannin and their derivatives, which were divided into the direct interaction involved in alkylating agent, covalently binding the DNA and protein, as well as the indirect interaction mediated by ROS, nonspecifically influencing the mitochondria or multiple signal pathways, will be systematically summarized and discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Trial watch

PubMed Central

Vacchelli, Erika; Galluzzi, Lorenzo; Fridman, Wolf Hervé; Galon, Jerome; Sautès-Fridman, Catherine; Tartour, Eric; Kroemer, Guido

2012-01-01

The long-established notion that apoptosis would be immunologically silent, and hence it would go unnoticed by the immune system, if not tolerogenic, and hence it would actively suppress immune responses, has recently been revisited. In some instances, indeed, cancer cells undergo apoptosis while emitting a spatiotemporally-defined combination of signals that renders them capable of eliciting a long-term protective antitumor immune response. Importantly, only a few anticancer agents can stimulate such an immunogenic cell death. These include cyclophosphamide, doxorubicin and oxaliplatin, which are currently approved by FDA for the treatment of multiple hematologic and solid malignancies, as well as mitoxantrone, which is being used in cancer therapy and against multiple sclerosis. In this Trial Watch, we will review and discuss the progress of recent (initiated after January 2008) clinical trials evaluating the off-label use of cyclophosphamide, doxorubicin, oxaliplatin and mitoxantrone. PMID:22720239

Immunogenicity and Safety of the New Inactivated Quadrivalent Influenza Vaccine Vaxigrip Tetra: Preliminary Results in Children ≥6 Months and Older Adults

PubMed Central

Montomoli, Emanuele; Torelli, Alessandro; Gianchecchi, Elena

2018-01-01

Since the mid-1980s, two lineages of influenza B viruses have been distinguished. These can co-circulate, limiting the protection provided by inactivated trivalent influenza vaccines (TIVs). This has prompted efforts to formulate quadrivalent influenza vaccines (QIVs), to enhance protection against circulating influenza B viruses. This review describes the results obtained from seven phase III clinical trials evaluating the immunogenicity, safety, and lot-to-lot consistency of a new quadrivalent split-virion influenza vaccine (Vaxigrip Tetra®) formulated by adding a second B strain to the already licensed TIV. Since Vaxigrip Tetra was developed by means of a manufacturing process strictly related to that used for TIV, the data on the safety profile of TIV are considered supportive of that of Vaxigrip Tetra. The safety and immunogenicity of Vaxigrip Tetra were similar to those of the corresponding licensed TIV. Moreover, the new vaccine elicits a superior immune response towards the additional strain, without affecting immunogenicity towards the other three strains. Vaxigrip Tetra is well tolerated, has aroused no safety concerns, and is recommended for the active immunization of individuals aged ≥6 months. In addition, preliminary data confirm its immunogenicity and safety even in children aged 6–35 months and its immunogenicity in older subjects (aged 66–80 years). PMID:29518013

Immunogenicity of Membrane-bound HIV-1 gp41 Membrane-proximal External Region (MPER) Segments Is Dominated by Residue Accessibility and Modulated by Stereochemistry*

PubMed Central

Kim, Mikyung; Song, Likai; Moon, James; Sun, Zhen-Yu J.; Bershteyn, Anna; Hanson, Melissa; Cain, Derek; Goka, Selasie; Kelsoe, Garnett; Wagner, Gerhard; Irvine, Darrell; Reinherz, Ellis L.

2013-01-01

Structural characterization of epitope-paratope pairs has contributed to the understanding of antigenicity. By contrast, few structural studies relate to immunogenicity, the process of antigen-induced immune responses in vivo. Using a lipid-arrayed membrane-proximal external region (MPER) of HIV-1 glycoprotein 41 as a model antigen, we investigated the influence of physicochemical properties on immunogenicity in relation to structural modifications of MPER/liposome vaccines. Anchoring the MPER to the membrane via an alkyl tail or transmembrane domain retained the MPER on liposomes in vivo, while preserving MPER secondary structure. However, structural modifications that affected MPER membrane orientation and antigenic residue accessibility strongly impacted induced antibody responses. The solvent-exposed MPER tryptophan residue (Trp-680) was immunodominant, focusing immune responses, despite sequence variability elsewhere. Nonetheless, immunogenicity could be readily manipulated using site-directed mutagenesis or structural constraints to modulate amino acid surface display. These studies provide fundamental insights for immunogen design aimed at targeting B cell antibody responses. PMID:24047898

Cutting Edge: Processing of Oxidized Peptides in Macrophages Regulates T Cell Activation and Development of Autoimmune Arthritis.

PubMed

Yang, Min; Haase, Claus; Viljanen, Johan; Xu, Bingze; Ge, Changrong; Kihlberg, Jan; Holmdahl, Rikard

2017-12-15

APCs are known to produce NADPH oxidase (NOX) 2 - derived reactive oxygen species; however, whether and how NOX2-mediated oxidation affects redox-sensitive immunogenic peptides remains elusive. In this study, we investigated a major immunogenic peptide in glucose-6-phosphate isomerase (G6PI), a potential autoantigen in rheumatoid arthritis, which can form internal disulfide bonds. Ag presentation assays showed that presentation of this G6PI peptide was more efficient in NOX2-deficient ( Ncf1 m1J/m1J mutant) mice, compared with wild-type controls. IFN-γ - inducible lysosomal thiol reductase (GILT), which facilitates disulfide bond-containing Ag processing, was found to be upregulated in macrophages from Ncf1 mutant mice. Ncf1 mutant mice exhibited more severe G6PI peptide-induced arthritis, which was accompanied by the increased GILT expression in macrophages and enhanced Ag-specific T cell responses. Our results show that NOX2-dependent processing of the redox-sensitive autoantigens by APCs modify T cell activity and development of autoimmune arthritis. Copyright © 2017 by The American Association of Immunologists, Inc.

Development of a vaccine against Streptococcus agalactiae in fish based on truncated cell wall surface anchor proteins.

PubMed

Liu, H; Zhang, S; Shen, Z; Ren, G; Liu, L; Ma, Y; Zhang, Y; Wang, W

2016-10-08

Streptococcus agalactiae is an important fish pathogen and a leading cause of major economic losses to the aquaculture industry worldwide. In the present study, the two truncated recombinant proteins of cell wall surface anchor family of S agalactiae, CWSAP465 and CWSAP1035, were expressed in Escherichia coli, and their immunogenicity and efficacy against the bacterium were evaluated in tilapia and turbot. The results showed that the prokaryotic expression of the two constructs, p32a-CWSAP465 and p32a-CWSAP1035, gave rise to a high yield of soluble proteins with good immunogenicity. The immunisation-challenge study revealed that tilapia and turbot immunised with recombinant truncated proteins produced high levels of antibodies with a peak at four weeks after immunisation and were protected from a challenge by a virulent S agalactiae at a dose of 1×10 9 colony forming units/ml. The recombinant truncated proteins had higher efficacy than the whole-cell inactivated vaccine. Therefore, the study demonstrated that CWSAP465 and CWSAP1035 are two viable vaccine candidates against S agalactiae in fish. British Veterinary Association.

[Immunoloical aspects of the antropogenic response to the antigens of symbiotic non-toxigenic diphtherial corynebacteria].

PubMed

Shmeleva, E A; Popkova, S M; Makarova, S I; Baturina, I G

2006-01-01

Corynebacteria, being ancient symbionts of open cavities of human body, carry unique, balanced immunogenic stimuli, formed in the process of evolution, thus maintaining non-specific resistance at a certain level. They favor formation of human microcenotic communities as a normal biological and physiological phenomenon. Codivak, a preparation of natural antigens of a symbiotic strain of non-toxigenic diphtherial corynebacteria, is able to correct not only disturbances of oropharyngeal immunity, but also general cell-mediated and humoral immunity disorders.

Recombinant Modified Vaccinia Virus Ankara Generating Ebola Virus-Like Particles.

PubMed

Schweneker, Marc; Laimbacher, Andrea S; Zimmer, Gert; Wagner, Susanne; Schraner, Elisabeth M; Wolferstätter, Michael; Klingenberg, Marieken; Dirmeier, Ulrike; Steigerwald, Robin; Lauterbach, Henning; Hochrein, Hubertus; Chaplin, Paul; Suter, Mark; Hausmann, Jürgen

2017-06-01

There are currently no approved therapeutics or vaccines to treat or protect against the severe hemorrhagic fever and death caused by Ebola virus (EBOV). Ebola virus-like particles (EBOV VLPs) consisting of the matrix protein VP40, the glycoprotein (GP), and the nucleoprotein (NP) are highly immunogenic and protective in nonhuman primates against Ebola virus disease (EVD). We have constructed a modified vaccinia virus Ankara-Bavarian Nordic (MVA-BN) recombinant coexpressing VP40 and GP of EBOV Mayinga and the NP of Taï Forest virus (TAFV) (MVA-BN-EBOV-VLP) to launch noninfectious EBOV VLPs as a second vaccine modality in the MVA-BN-EBOV-VLP-vaccinated organism. Human cells infected with either MVA-BN-EBOV-VLP or MVA-BN-EBOV-GP showed comparable GP expression levels and transport of complex N-glycosylated GP to the cell surface. Human cells infected with MVA-BN-EBOV-VLP produced large amounts of EBOV VLPs that were decorated with GP spikes but excluded the poxviral membrane protein B5, thus resembling authentic EBOV particles. The heterologous TAFV NP enhanced EBOV VP40-driven VLP formation with efficiency similar to that of the homologous EBOV NP in a transient-expression assay, and both NPs were incorporated into EBOV VLPs. EBOV GP-specific CD8 T cell responses were comparable between MVA-BN-EBOV-VLP- and MVA-BN-EBOV-GP-immunized mice. The levels of EBOV GP-specific neutralizing and binding antibodies, as well as GP-specific IgG1/IgG2a ratios induced by the two constructs, in mice were also similar, raising the question whether the quality rather than the quantity of the GP-specific antibody response might be altered by an EBOV VLP-generating MVA recombinant. IMPORTANCE The recent outbreak of Ebola virus (EBOV), claiming more than 11,000 lives, has underscored the need to advance the development of safe and effective filovirus vaccines. Virus-like particles (VLPs), as well as recombinant viral vectors, have proved to be promising vaccine candidates. Modified vaccinia virus Ankara-Bavarian Nordic (MVA-BN) is a safe and immunogenic vaccine vector with a large capacity to accommodate multiple foreign genes. In this study, we combined the advantages of VLPs and the MVA platform by generating a recombinant MVA-BN-EBOV-VLP that would produce noninfectious EBOV VLPs in the vaccinated individual. Our results show that human cells infected with MVA-BN-EBOV-VLP indeed formed and released EBOV VLPs, thus producing a highly authentic immunogen. MVA-BN-EBOV-VLP efficiently induced EBOV-specific humoral and cellular immune responses in vaccinated mice. These results are the basis for future advancements, e.g., by including antigens from various filoviral species to develop multivalent VLP-producing MVA-based filovirus vaccines. Copyright © 2017 American Society for Microbiology.

Cytokine treatment optimises the immunotherapeutic effects of umbilical cord-derived MSC for treatment of inflammatory liver disease.

PubMed

de Witte, Samantha F H; Merino, Ana M; Franquesa, Marcella; Strini, Tanja; van Zoggel, Johanna A A; Korevaar, Sander S; Luk, Franka; Gargesha, Madhu; O'Flynn, Lisa; Roy, Debashish; Elliman, Steve J; Newsome, Philip N; Baan, Carla C; Hoogduijn, Martin J

2017-06-08

Mesenchymal stromal cells (MSC) possess immunomodulatory properties and low immunogenicity, both crucial properties for their development into an effective cellular immunotherapy. They have shown benefit in clinical trials targeting liver diseases; however the efficacy of MSC therapy will benefit from improvement of the immunomodulatory and immunogenic properties of MSC. MSC derived from human umbilical cords (ucMSC) were treated for 3 days in vitro with various inflammatory factors, interleukins, vitamins and serum deprivation. Their immunogenicity and immunomodulatory capacity were examined by gene-expression analysis, surface-marker expressions, IDO activity, PGE 2 secretion and inhibition of T cell proliferation and IFNγ production. Furthermore, their activation of NK cell cytotoxicity was investigated via CD107a expression on NK cells. The immunomodulatory capacity, biodistribution and survival of pre-treated ucMSC were investigated in a CCl 4 -induced liver disease mouse model. In addition, capacity of pre-treated MSC to ameliorate liver inflammation was examined in an ex vivo liver inflammation co-culture model. IFN-γ and a multiple cytokine cocktail (MC) consisting of IFN-γ, TGFβ and retinoic acid upregulated the expression of immunomodulatory factor PD-L1 and IDO activity. Subsequently, both treatments enhanced the capacity of ucMSC to inhibit CD4 and CD8 T cell proliferation and IFN-γ production. The susceptibility of ucMSC for NK cell lysis was decreased by IFN-β, TGFβ and MC treatment. In vivo, no immunomodulation was observed by the ucMSC. Four hours after intravenous infusion in mice with CCl 4 -induced inflammatory liver injury, the majority of ucMSC were trapped in the lungs. Rapid clearance of ucMSC(VitB 6 ), ucMSC(Starv + VitB 6 ) and ucMSC(MC) and altered bio-distribution of ucMSC(TGFβ) compared to untreated ucMSC was observed. In the ex vivo co-culture system with inflammatory liver slices ucMSC(MC) showed significantly enhanced modulatory capacity compared to untreated ucMSC. The present study demonstrates the responsiveness of ucMSC to in vitro optimisation treatment. The observed improvements in immunomodulatory capacity as well as immunogenicity after MC treatment may improve the efficacy of ucMSC as immunotherapy targeted towards liver inflammation.

Meningococcal vaccine development--from glycoconjugates against MenACWY to proteins against MenB--potential for broad protection against meningococcal disease.

PubMed

Dull, Peter M; McIntosh, E David

2012-05-30

Novartis Vaccines has a long-standing research and development interest in the prevention of invasive meningococcal disease. From the initial licensure of the monovalent meningococcal C glycoconjugate vaccine, Menjugate(®), in response to the emergence of a virulent serogroup C ST-11 strain in the United Kingdom to the more recent development and licensure of a quadrivalent meningococcal ACWY glycoconjugate vaccine, Menveo(®), Novartis has a continuing commitment to the development of more effective tools for the control of meningococcal disease. Menveo is now licensed for use in adolescents and adults in over 50 countries and results from phase III studies have shown the vaccine to be well-tolerated and highly immunogenic in infants with vaccination beginning from 2 months of age. The 'holy grail' of meningococcal disease control is a broadly protective vaccine against serogroup B (MenB), preferably a vaccine that protects all age groups including infants. As the serogroup B capsule is poorly immunogenic, efforts over the past 40 years have focused on identifying conserved proteins expressed on the bacterial surface that elicit bactericidal antibodies. Novartis has approached this problem utilizing genomic tools to identify proteins meeting these criteria in a process now known as 'reverse vaccinology'[1]. This process has resulted in a novel multicomponent MenB vaccine (4CMenB) that consists of four major immunogenic components (three subcapsular MenB protein antigens plus outer membrane vesicles (OMVs) which themselves provide multiple subcapsular antigens, the immunodominant one being PorA). These all induce bactericidal antibodies against the antigens that are important in determining the survival, function, and virulence of the meningococci. Phase II studies of 4CMenB have been completed and have demonstrated that the vaccine is highly immunogenic against reference meningococcal strains selected to support licensure. Post-vaccination sera from clinical studies have also been tested against a diverse panel of serogroup B strains to support the development of the Meningococcal Antigen Typing System (MATS), a tool used to predict vaccine strain coverage [2] This overview is intended to give a broad summary of the key clinical data derived from the Menveo and 4CMenB clinical development programs. Copyright © 2012. Published by Elsevier Ltd.

Ribosomal vaccines. I. Immunogenicity of ribosomal fractions isolated from Salmonella typhimurium and Yersinia pestis.

PubMed

Johnson, W

1972-06-01

The immunogenicity of ribosomes and ribosomal subfractions isolated from Yersina pestis and Salmonella typhimurium has been studied. Ribosomes and ribosomal protein isolated from S. typhimurium protected mice against lethal challenge. Ribosomal ribonucleic acid isolated by phenol extraction failed to induce any significant level of protection in mice. None of the ribosomes or ribosomal subfractions isolated from Y. pestis were effective in inducing immunity to lethal challenge. These results suggest that the immunogen of the ribosomal vaccine is protein.

Ribosomal Vaccines I. Immunogenicity of Ribosomal Fractions Isolated from Salmonella typhimurium and Yersinia pestis

PubMed Central

Johnson, William

1972-01-01

The immunogenicity of ribosomes and ribosomal subfractions isolated from Yersina pestis and Salmonella typhimurium has been studied. Ribosomes and ribosomal protein isolated from S. typhimurium protected mice against lethal challenge. Ribosomal ribonucleic acid isolated by phenol extraction failed to induce any significant level of protection in mice. None of the ribosomes or ribosomal subfractions isolated from Y. pestis were effective in inducing immunity to lethal challenge. These results suggest that the immunogen of the ribosomal vaccine is protein. Images PMID:4564407

Structure of a High-Affinity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saphire, E.O.; Montero, M.; Menendez, A.

2007-07-13

The human antibody b12 recognizes a discontinuous epitope on gp120 and is one of the rare monoclonal antibodies that neutralize a broad range of primary human immunodeficiency virus type 1 (HIV-1) isolates. We previously reported the isolation of B2.1, a dimeric peptide that binds with high specificity to b12 and competes with gp120 for b12 antibody binding. Here, we show that the affinity of B2.1 was improved 60-fold over its synthetic-peptide counterpart by fusing it to the N terminus of a soluble protein. This affinity, which is within an order of magnitude of that of gp120, probably more closely reflectsmore » the affinity of the phage-borne peptide. The crystal structure of a complex between Fab of b12 and B2.1 was determined at 1.8 Angstrom resolution. The structural data allowed the differentiation of residues that form critical contacts with b12 from those required for maintenance of the antigenic structure of the peptide, and revealed that three contiguous residues mediate B2.1's critical contacts with b12. This single region of critical contact between the B2.1 peptide and the b12 paratope is unlikely to mimic the discontinuous key binding residues involved in the full b12 epitope for gp120, as previously identified by alanine scanning substitutions on the gp120 surface. These structural observations are supported by experiments that demonstrate that B2.1 is an ineffective immunogenic mimic of the b12 epitope on gp120. Indeed, an extensive series of immunizations with B2.1 in various forms failed to produce gp120 cross-reactive sera. The functional and structural data presented here, however, suggest that the mechanism by which b12 recognizes the two antigens is very different. Here, we present the first crystal structure of peptide bound to an antibody that was originally raised against a discontinuous protein epitope. Our results highlight the challenge of producing immunogens that mimic discontinuous protein epitopes, and the necessity of combining complementary experimental approaches in analyzing the antigenic and immunogenic properties of putative molecular mimics.« less

POPISK: T-cell reactivity prediction using support vector machines and string kernels

PubMed Central

2011-01-01

Background Accurate prediction of peptide immunogenicity and characterization of relation between peptide sequences and peptide immunogenicity will be greatly helpful for vaccine designs and understanding of the immune system. In contrast to the prediction of antigen processing and presentation pathway, the prediction of subsequent T-cell reactivity is a much harder topic. Previous studies of identifying T-cell receptor (TCR) recognition positions were based on small-scale analyses using only a few peptides and concluded different recognition positions such as positions 4, 6 and 8 of peptides with length 9. Large-scale analyses are necessary to better characterize the effect of peptide sequence variations on T-cell reactivity and design predictors of a peptide's T-cell reactivity (and thus immunogenicity). The identification and characterization of important positions influencing T-cell reactivity will provide insights into the underlying mechanism of immunogenicity. Results This work establishes a large dataset by collecting immunogenicity data from three major immunology databases. In order to consider the effect of MHC restriction, peptides are classified by their associated MHC alleles. Subsequently, a computational method (named POPISK) using support vector machine with a weighted degree string kernel is proposed to predict T-cell reactivity and identify important recognition positions. POPISK yields a mean 10-fold cross-validation accuracy of 68% in predicting T-cell reactivity of HLA-A2-binding peptides. POPISK is capable of predicting immunogenicity with scores that can also correctly predict the change in T-cell reactivity related to point mutations in epitopes reported in previous studies using crystal structures. Thorough analyses of the prediction results identify the important positions 4, 6, 8 and 9, and yield insights into the molecular basis for TCR recognition. Finally, we relate this finding to physicochemical properties and structural features of the MHC-peptide-TCR interaction. Conclusions A computational method POPISK is proposed to predict immunogenicity with scores which are useful for predicting immunogenicity changes made by single-residue modifications. The web server of POPISK is freely available at http://iclab.life.nctu.edu.tw/POPISK. PMID:22085524

POPISK: T-cell reactivity prediction using support vector machines and string kernels.

PubMed

Tung, Chun-Wei; Ziehm, Matthias; Kämper, Andreas; Kohlbacher, Oliver; Ho, Shinn-Ying

2011-11-15

Accurate prediction of peptide immunogenicity and characterization of relation between peptide sequences and peptide immunogenicity will be greatly helpful for vaccine designs and understanding of the immune system. In contrast to the prediction of antigen processing and presentation pathway, the prediction of subsequent T-cell reactivity is a much harder topic. Previous studies of identifying T-cell receptor (TCR) recognition positions were based on small-scale analyses using only a few peptides and concluded different recognition positions such as positions 4, 6 and 8 of peptides with length 9. Large-scale analyses are necessary to better characterize the effect of peptide sequence variations on T-cell reactivity and design predictors of a peptide's T-cell reactivity (and thus immunogenicity). The identification and characterization of important positions influencing T-cell reactivity will provide insights into the underlying mechanism of immunogenicity. This work establishes a large dataset by collecting immunogenicity data from three major immunology databases. In order to consider the effect of MHC restriction, peptides are classified by their associated MHC alleles. Subsequently, a computational method (named POPISK) using support vector machine with a weighted degree string kernel is proposed to predict T-cell reactivity and identify important recognition positions. POPISK yields a mean 10-fold cross-validation accuracy of 68% in predicting T-cell reactivity of HLA-A2-binding peptides. POPISK is capable of predicting immunogenicity with scores that can also correctly predict the change in T-cell reactivity related to point mutations in epitopes reported in previous studies using crystal structures. Thorough analyses of the prediction results identify the important positions 4, 6, 8 and 9, and yield insights into the molecular basis for TCR recognition. Finally, we relate this finding to physicochemical properties and structural features of the MHC-peptide-TCR interaction. A computational method POPISK is proposed to predict immunogenicity with scores which are useful for predicting immunogenicity changes made by single-residue modifications. The web server of POPISK is freely available at http://iclab.life.nctu.edu.tw/POPISK.

Recent advances in the use of gelatin in biomedical research.

PubMed

Su, Kai; Wang, Chunming

2015-11-01

The biomacromolecule, gelatin, has increasingly been used in biomedicine-beyond its traditional use in food and cosmetics. The appealing advantages of gelatin, such as its cell-adhesive structure, low cost, off-the-shelf availability, high biocompatibility, biodegradability and low immunogenicity, among others, have made it a desirable candidate for the development of biomaterials for tissue engineering and drug delivery. Gelatin can be formulated in the form of nanoparticles, employed as size-controllable porogen, adopted as surface coating agent and mixed with synthetic or natural biopolymers forming composite scaffolds. In this article, we review recent advances in the versatile applications of gelatin within biomedical context and attempt to draw upon its advantages and potential challenges.

Development of a Vaccine Incorporating Killed Virus of Canine Origin for the Prevention of Canine Parvovirus Infection

PubMed Central

Povey, C.

1982-01-01

A parvovirus of canine origin, cultured in a feline kidney cell line, was inactivated with formalin. Three pilot serials were produced and three forms of finished vaccine (nonadjuvanted, single adjuvanted and double adjuvanted) were tested in vaccination and challenge trials. A comparison was also made with two inactivated feline panleukopenia virus vaccines, one of which has official approval for use in dogs. The inactivated canine vaccine in nonadjuvanted, adjuvanted or double adjuvanted form was immunogenic in 20 of 20 vaccinated dogs. The double adjuvanted vaccine is selected as the one of choice on the basis of best and most persistent seriological response. PMID:7039811

Recognition of the different structural forms of the capsid protein determines the outcome following infection with porcine circovirus type 2.

PubMed

Trible, Benjamin R; Suddith, Andrew W; Kerrigan, Maureen A; Cino-Ozuna, Ada G; Hesse, Richard A; Rowland, Raymond R R

2012-12-01

Porcine circovirus type 2 (PCV2) capsid protein (CP) is the only protein necessary for the formation of the virion capsid, and recombinant CP spontaneously forms virus-like particles (VLPs). Located within a single CP subunit is an immunodominant epitope consisting of residues 169 to 180 [CP(169-180)], which is exposed on the surface of the subunit, but, in the structural context of the VLP, the epitope is buried and inaccessible to antibody. High levels of anti-CP(169-180) activity are associated with porcine circovirus-associated disease (PCVAD). The purpose of this study was to investigate the role of the immune response to monomer CP in the development of PCVAD. The approach was to immunize pigs with CP monomer, followed by challenge with PCV2 and porcine reproductive and respiratory syndrome virus (PRRSV). To maintain the CP immunogen as a stable monomer, CP(43-233) was fused to ubiquitin (Ub-CP). Size exclusion chromatography showed that Ub-CP was present as a single 33-kDa protein. Pigs immunized with Ub-CP developed a strong antibody response to PCV2, including antibodies against CP(169-180). However, only low levels of virus neutralizing activity were detected, and viremia levels were similar to those of nonimmunized pigs. As a positive control, immunization with baculovirus-expressed CP (Bac-CP) resulted in high levels of virus neutralizing activity, small amounts of anti-CP(169-180) activity, and the absence of viremia in pigs following virus challenge. The data support the role of CP(169-180) as an immunological decoy and illustrate the importance of the structural form of the CP immunogen in determining the outcome following infection.

Immunogenicity of HILDA/LIF either in a soluble or in a membrane anchored form expressed in vivo by recombinant vaccinia viruses.

PubMed

Taupin, J L; Acres, B; Dott, K; Schmitt, D; Kieny, M P; Gualde, N; Moreau, J F

1993-09-01

Insertion of various cDNAs in the genome of the vaccinia virus (VV) enables the in vivo and in vitro study of the functional role and/or the immunogenicity of the virally encoded recombinant proteins. We have prepared a recombinant VV expressing the cDNA of the human cytokine HILDA/LIF (human interleukin for DA cells/leukaemia inhibitory factor), and used this virus to immunize mice against this protein, which is very homologous to its murine counterpart (approximately 80% homology). We also constructed and expressed by the same system a chimeric gene encoding the HILDA/LIF protein fused to the 37 COOH-terminal amino-acids of the human decay accelerating factor (DAF). This sequence proved to be sufficient for the targeting of the fusion protein to the cell membrane, where it is linked to the phosphatidylinositols. Both recombinant VVs induced cytokine-specific antibodies in mice as analysed with an ELISA where the recombinant HILDA/LIF was plastic-coated and a cytofluorometric assay where the LIF-DAF molecule was present at the cell surface of stably transfected P815. In the latter case HILDA/LIF remained biologically active suggesting that it was expressed in its native form. The LIF-DAF fusion protein was found to exhibit a better capacity to elicit an antibody response against the native form of the cytokine as detected in cytofluorometric assays. Whatever the recombinant virus used to immunize the mice, the MoAbs obtained were positive either in the ELISA or in the cytofluorometric assays but one, which suggested that the plastic coating induced a conformational change of HILDA/LIF.

Nucleic acids encoding mosaic HIV-1 gag proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korber, Bette T.; Perkins, Simon; Bhattacharya, Tanmoy

The disclosure generally relates to an immunogenic composition (e.g., a vaccine) and, in particular, to a polyvalent immunogenic composition, such as a polyvalent HIV vaccine, and to methods of using same.

CYD-TDV dengue vaccine: systematic review and meta-analysis of efficacy, immunogenicity and safety.

PubMed

Godói, Isabella Piassi; Lemos, Livia Lovato Pires; de Araújo, Vânia Eloisa; Bonoto, Braúlio Cesar; Godman, Brian; Guerra Júnior, Augusto Afonso

2017-03-01

Dengue virus (DENV) is a serious global health problem. CYD-TDC (Dengvaxia ® ) was the first vaccine to gain regulatory approval to try and address this problem. Summarize all available evidence on the immunogenicity, efficacy and safety of the CYD-TDV dengue vaccine. Meta-analysis and systematic review. The best and worst immunogenicity results were for DENV4 and DENV1, respectively. Vaccine efficacy of 60% was derived from studies with participants aged 2-16 years old, with DENV4 and DENV2 presenting the best and worst results, respectively. Erythema and swelling were more frequent with CYD-TDV. No differences were detected for systemic adverse events. CYD-TDV showed moderate efficacy in children and adolescents. From the immunogenicity results in adults, we can expect satisfactory efficacy from vaccination in this population.

Use of Prior Vaccinations for the Development of New Vaccines

NASA Astrophysics Data System (ADS)

Etlinger, H. M.; Gillessen, D.; Lahm, H.-W.; Matile, H.; Schonfeld, H.-J.; Trzeciak, A.

1990-07-01

There is currently a need for vaccine development to improve the immunogenicity of protective epitopes, which themselves are often poorly immunogenic. Although the immunogenicity of these epitopes can be enhanced by linking them to highly immunogenic carriers, such carriers derived from current vaccines have not proven to be generally effective. One reason may be related to epitope-specific suppression, in which prior vaccination with a protein can inhibit the antibody response to new epitopes linked to the protein. To circumvent such inhibition, a peptide from tetanus toxoid was identified that, when linked to a B cell epitope and injected into tetanus toxoid-primed recipients, retained sequences for carrier but not suppressor function. The antibody response to the B cell epitope was enhanced. This may be a general method for taking advantage of previous vaccinations in the development of new vaccines.

Immunogenicity of biologically-derived therapeutics: assessment and interpretation of nonclinical safety studies.

PubMed

Ponce, Rafael; Abad, Leslie; Amaravadi, Lakshmi; Gelzleichter, Thomas; Gore, Elizabeth; Green, James; Gupta, Shalini; Herzyk, Danuta; Hurst, Christopher; Ivens, Inge A; Kawabata, Thomas; Maier, Curtis; Mounho, Barbara; Rup, Bonita; Shankar, Gopi; Smith, Holly; Thomas, Peter; Wierda, Dan

2009-07-01

An evaluation of potential antibody formation to biologic therapeutics during the course of nonclinical safety studies and its impact on the toxicity profile is expected under current regulatory guidance and is accepted standard practice. However, approaches for incorporating this information in the interpretation of nonclinical safety studies are not clearly established. Described here are the immunological basis of anti-drug antibody formation to biopharmaceuticals (immunogenicity) in laboratory animals, and approaches for generating and interpreting immunogenicity data from nonclinical safety studies of biotechnology-derived therapeutics to support their progression to clinical evaluation. We subscribe that immunogenicity testing strategies should be adapted to the specific needs of each therapeutic development program, and data generated from such analyses should be integrated with available clinical and anatomic pathology, pharmacokinetic, and pharmacodynamic data to properly interpret nonclinical studies.

Screening of primary gp120 immunogens to formulate the next generation polyvalent DNA prime-protein boost HIV-1 vaccines

PubMed Central

Wang, Shixia; Chou, Te-hui; Hackett, Anthony; Efros, Veronica; Wang, Yan; Han, Dong; Wallace, Aaron; Chen, Yuxin; Hu, Guangnan; Liu, Shuying; Clapham, Paul; Arthos, James; Montefiori, David; Lu, Shan

2017-01-01

ABSTRACT Our previous preclinical studies and a Phase I clinical trial DP6-001 have indicated that a polyvalent Env formulation was able to elicit broadly reactive antibody responses including low titer neutralizing antibody responses against viral isolates of subtypes A, B, C and AE. In the current report, a panel of 62 gp120 immunogens were screened in a rabbit model to identify gp120 immunogens that can elicit improved binding and neutralizing antibody responses and some of them can be included in the next polyvalent formulation. Only about 19% of gp120 immunogens in this panel were able to elicit neutralizing antibodies against greater than 50% of the viruses included in a high throughput PhenoSense neutralization assay when these immuongens were tested as a DNA prime followed by a fixed 5-valent gp120 protein vaccine boost. The new polyvalent formulation, using five gp120 immunogens selected from this subgroup, elicited improved quality of antibody responses in rabbits than the previous DP6-001 formulation. More significantly, this new polyvalent formulation elicited higher antibody responses against a panel of gp70V1/V2 antigens expressing V1/V2 sequences from diverse subtypes. Bioinformatics analysis supports the design of a 4-valent or 5-valent formulation using gp120 immunogens from this screening study to achieve a broad coverage against 16 HIV-1 subtypes. PMID:28933684

Chicken IgY Fc expressed by Eimeria mitis enhances the immunogenicity of E. mitis.

PubMed

Qin, Mei; Tang, Xinming; Yin, Guangwen; Liu, Xianyong; Suo, Jingxia; Tao, Geru; Ei-Ashram, Saeed; Li, Yuan; Suo, Xun

2016-03-21

Eimeria species are obligate intracellular apicomplexan parasites, causing great economic losses in the poultry industry. Currently wild-and attenuated- type anticoccidial vaccines are used to control coccidiosis. However, their use in fast growing broilers is limited by vaccination side effects caused by medium and/or low immunogenic Eimeria spp. There is, therefore, a need for a vaccine with high immunogenicity for broilers. The avian yolk sac IgY Fc is the avian counterpart of the mammalian IgG Fc, which enhances immunogenicity of Fc-fusion proteins. Here, we developed a stable transgenic Eimeria mitis expressing IgY Fc (Emi.chFc) and investigated whether the avian IgY Fc fragment enhances the immunogenicity of E. mitis. Two-week-old broilers were immunized with either Emi.chFc or wild type Eimeria and challenged with wild type E. mitis to analyze the protective properties of transgenic Emi.chFc. Chickens immunized with Emi.chFc had significantly lower oocyst output, in comparison with PBS, mock control (transgenic E. mitis expressing HA1 from H9N2 avian influenza virus) and wildtype E. mitis immunized groups after challenge, indicating that IgY Fc enhanced the immunogenicity of E. mitis. Our findings suggest that IgY Fc-expressing Eimeria may be a better coccidiosis vaccine, and transgenic Eimeria expressing Fc-fused exogenous antigens may be used as a novel vaccine-delivery vehicle against a wide variety of pathogens.

Aleuria Aurantia Lectin (AAL)-Reactive Immunoglobulin G Rapidly Appears in Sera of Animals following Antigen Exposure

PubMed Central

Chen, Songming; Lu, Chen; Gu, Hongbo; Mehta, Anand; Li, Jianwei; Romano, Patrick B.; Horn, David; Hooper, D. Craig; Bazemore-Walker, Carthene R.; Block, Timothy

2012-01-01

We have discovered an Aleuria Aurantia Lectin (AAL)-reactive immunoglobulin G (IgG) that naturally occurs in the circulation of rabbits and mice, following immune responses induced by various foreign antigens. AAL can specifically bind to fucose moieties on glycoproteins. However, most serum IgGs are poorly bound by AAL unless they are denatured or treated with glycosidase. In this study, using an immunogen-independent AAL-antibody microarray assay that we developed, we detected AAL-reactive IgG in the sera of all animals that had been immunized 1–2 weeks previously with various immunogens with and without adjuvants and developed immunogen-specific responses. All of these animals subsequently developed immunogen-specific immune responses. The kinetics of the production of AAL-reactive IgG in mice and rabbits were distinct from those of the immunogen-specific IgGs elicited in the same animals: they rose and fell within one to two weeks, and peaked between four to seven days after exposure, while immunogen-specific IgGs continued to rise during the same period. Mass spectrometric profiling of the Fc glycoforms of purified AAL-reactive IgGs indicates that these are mainly comprised of IgGs with core-fucosylated and either mono-or non-galactosylated Fc N-glycan structures. Our results suggest that AAL-reactive IgG could be a previously unrecognized IgG subset that is selectively produced at the onset of a humoral response. PMID:23024749

Immune Protection of Nonhuman Primates against Ebola Virus with Single Low-Dose Adenovirus Vectors Encoding Modified GPs

PubMed Central

Geisbert, Joan B; Shedlock, Devon J; Xu, Ling; Lamoreaux, Laurie; Custers, Jerome H. H. V; Popernack, Paul M; Yang, Zhi-Yong; Pau, Maria G; Roederer, Mario; Koup, Richard A; Goudsmit, Jaap; Jahrling, Peter B; Nabel, Gary J

2006-01-01

Background Ebola virus causes a hemorrhagic fever syndrome that is associated with high mortality in humans. In the absence of effective therapies for Ebola virus infection, the development of a vaccine becomes an important strategy to contain outbreaks. Immunization with DNA and/or replication-defective adenoviral vectors (rAd) encoding the Ebola glycoprotein (GP) and nucleoprotein (NP) has been previously shown to confer specific protective immunity in nonhuman primates. GP can exert cytopathic effects on transfected cells in vitro, and multiple GP forms have been identified in nature, raising the question of which would be optimal for a human vaccine. Methods and Findings To address this question, we have explored the efficacy of mutant GPs from multiple Ebola virus strains with reduced in vitro cytopathicity and analyzed their protective effects in the primate challenge model, with or without NP. Deletion of the GP transmembrane domain eliminated in vitro cytopathicity but reduced its protective efficacy by at least one order of magnitude. In contrast, a point mutation was identified that abolished this cytopathicity but retained immunogenicity and conferred immune protection in the absence of NP. The minimal effective rAd dose was established at 1010 particles, two logs lower than that used previously. Conclusions Expression of specific GPs alone vectored by rAd are sufficient to confer protection against lethal challenge in a relevant nonhuman primate model. Elimination of NP from the vaccine and dose reductions to 1010 rAd particles do not diminish protection and simplify the vaccine, providing the basis for selection of a human vaccine candidate. PMID:16683867

The double-edged sword: How evolution can make or break a live-attenuated virus vaccine

PubMed Central

Hanley, Kathryn A.

2012-01-01

Even students who reject evolution are often willing to consider cases in which evolutionary biology contributes to, or undermines, biomedical interventions. Moreover the intersection of evolutionary biology and biomedicine is fascinating in its own right. This review offers an overview of the ways in which evolution has impacted the design and deployment of live-attenuated virus vaccines, with subsections that may be useful as lecture material or as the basis for case studies in classes at a variety of levels. Live- attenuated virus vaccines have been modified in ways that restrain their replication in a host, so that infection (vaccination) produces immunity but not disease. Applied evolution, in the form of serial passage in novel host cells, is a “classical” method to generate live-attenuated viruses. However many live-attenuated vaccines exhibit reversion to virulence through back-mutation of attenuating mutations, compensatory mutations elsewhere in the genome, recombination or reassortment, or changes in quasispecies diversity. Additionally the combination of multiple live-attenuated strains may result in competition or facilitation between individual vaccine viruses, resulting in undesirable increases in virulence or decreases in immunogenicity. Genetic engineering informed by evolutionary thinking has led to a number of novel approaches to generate live-attenuated virus vaccines that contain substantial safeguards against reversion to virulence and that ameliorate interference among multiple vaccine strains. Finally, vaccines have the potential to shape the evolution of their wild type counterparts in counter-productive ways; at the extreme vaccine-driven eradication of a virus may create an empty niche that promotes the emergence of new viral pathogens. PMID:22468165

Rescue of Pompe disease in mice by AAV-mediated liver delivery of secretable acid α-glucosidase

PubMed Central

Puzzo, Francesco; Colella, Pasqualina; Biferi, Maria G.; Bali, Deeksha; Paulk, Nicole K.; Vidal, Patrice; Collaud, Fanny; Simon-Sola, Marcelo; Charles, Severine; Hardet, Romain; Leborgne, Christian; Meliani, Amine; Cohen-Tannoudji, Mathilde; Astord, Stephanie; Gjata, Bernard; Sellier, Pauline; van Wittenberghe, Laetitia; Vignaud, Alban; Boisgerault, Florence; Barkats, Martine; Laforet, Pascal; Kay, Mark A.; Koeberl, Dwight D.; Ronzitti, Giuseppe; Mingozzi, Federico

2018-01-01

Glycogen storage disease type II or Pompe disease is a severe neuromuscular disorder caused by mutations in the lysosomal enzyme, acid α-glucosidase (GAA), which result in pathological accumulation of glycogen throughout the body. Enzyme replacement therapy is available for Pompe disease; however, it has limited efficacy, has high immunogenicity, and fails to correct pathological glycogen accumulation in nervous tissue and skeletal muscle. Using bioinformatics analysis and protein engineering, we developed transgenes encoding GAA that could be expressed and secreted by hepatocytes. Then, we used adeno-associated virus (AAV) vectors optimized for hepatic expression to deliver the GAA transgenes to Gaa knockout (Gaa−/−) mice, a model of Pompe disease. Therapeutic gene transfer to the liver rescued glycogen accumulation in muscle and the central nervous system, and ameliorated cardiac hypertrophy as well as muscle and respiratory dysfunction in the Gaa−/− mice; mouse survival was also increased. Secretable GAA showed improved therapeutic efficacy and lower immunogenicity compared to nonengineered GAA. Scale-up to nonhuman primates, and modeling of GAA expression in primary human hepatocytes using hepatotropic AAV vectors, demonstrated the therapeutic potential of AAV vector–mediated liver expression of secretable GAA for treating pathological glycogen accumulation in multiple tissues in Pompe disease. PMID:29187643

Immunostimulatory Effects of Melphalan and Usefulness in Adoptive Cell Therapy with Antitumor CD4+ T Cells.

PubMed

Kuczma, Michal; Ding, Zhi-Chun; Zhou, Gang

2016-01-01

The alkylating agent melphalan is used in the treatment of hematological malignancies, especially multiple myeloma. In the past, the usefulness of melphalan has been solely attributed to its cytotoxicity on fastgrowing cancerous cells. Although the immunomodulatory effects of melphalan were suggested many years ago, only recently has this aspect of melphalan's activity begun to be elucidated at the molecular level. Emerging evidence indicates that melphalan can foster an immunogenic microenvironment by inducing immunogenic cell death (ICD) as characterized by membrane translocation of endoplasmic reticulum protein calreticulin (CRT) and by release of chromatin-binding protein high-mobility group box 1 (HMGB1). In addition, the lympho-depletive effect of melphalan can induce the release of pro-inflammatory cytokines and growth factors, deplete regulatory T cells, and create space to facilitate the expansion of infused tumor-reactive T cells. These features suggest that melphalan can be used as a preparative chemotherapy for adoptive T-cell therapy. This notion is supported by our recent work demonstrating that the combination of melphalan and adoptive transfer of tumor-reactive CD4+ T cells can mediate potent antitumor effects in animal models. This review summarizes the recent advances in understanding and utilizing the immunomodulatory effects of melphalan.

Immunostimulatory Effects of Melphalan and Usefulness in Adoptive Cell Therapy with Antitumor CD4+ T Cells

PubMed Central

Kuczma, Michal; Ding, Zhi-Chun; Zhou, Gang

2017-01-01

The alkylating agent melphalan is used in the treatment of hematological malignancies, especially multiple myeloma. In the past, the usefulness of melphalan has been solely attributed to its cytotoxicity on fast-growing cancerous cells. Although the immunomodulatory effects of melphalan were suggested many years ago, only recently has this aspect of melphalan’s activity begun to be elucidated at the molecular level. Emerging evidence indicates that melphalan can foster an immunogenic microenvironment by inducing immunogenic cell death (ICD) as characterized by membrane translocation of endoplasmic reticulum protein calreticulin (CRT) and by release of chromatin-binding protein high-mobility group box 1 (HMGB1). In addition, the lympho-depletive effect of melphalan can induce the release of pro-inflammatory cytokines and growth factors, deplete regulatory T cells, and create space to facilitate the expansion of infused tumor-reactive T cells. These features suggest that melphalan can be used as a preparative chemotherapy for adoptive T-cell therapy. This notion is supported by our recent work demonstrating that the combination of melphalan and adoptive transfer of tumor-reactive CD4+ T cells can mediate potent antitumor effects in animal models. This review summarizes the recent advances in understanding and utilizing the immunomodulatory effects of melphalan. PMID:27910767

Oral Modeling of an Adenovirus-Based Quadrivalent Influenza Vaccine in Ferrets and Mice.

PubMed

Scallan, Ciaran D; Lindbloom, Jonathan D; Tucker, Sean N

2016-06-01

Oral vaccines delivered as tablets offer a number of advantages over traditional parenteral-based vaccines including the ease of delivery, lack of needles, no need for trained medical personnel, and the ability to formulate into temperature-stable tablets. We have been evaluating an oral vaccine platform based on recombinant adenoviral vectors for the purpose of creating a prophylactic vaccine to prevent influenza, and have demonstrated vaccine efficacy in animal models and substantial immunogenicity in humans. These studies have evaluated monovalent vaccines to date. To protect against the major circulating A and B influenza strains, a multivalent influenza vaccine will be required. In this study, the immunogenicity of orally delivered monovalent, bivalent, trivalent, and quadrivalent vaccines was tested in ferrets and mice. The various vaccine combinations were tested by blending monovalent recombinant adenovirus vaccines, each expressing hemagglutinin from a single strain. Human tablet delivery was modeled in animals by oral gavage in mice and by endoscopic delivery in ferrets. We demonstrated minimal interference between the various vaccine vectors when used in combination and that the oral quadrivalent vaccine compared favorably to an approved trivalent inactivated vaccine. The quadrivalent vaccine presented here produced immune responses that we predict should be capable of providing protection against multiple influenza strains, and the platform should have applications to other multivalent vaccines. Vaxart, Inc.

Progress with infliximab biosimilars for inflammatory bowel disease.

PubMed

Kurti, Zsuzsanna; Gonczi, Lorant; Lakatos, Peter L

2018-04-29

Biological therapies have revolutionized the treatment of inflammatory bowel diseases (IBD) in the last two decades. Though biological drugs are effective, their use is associated with high costs and access to biological agents varies among countries. As the patent for the reference products expired, the advent of biosimilar monoclonal antibodies has been expected. Biosimilars represent less expensive alternatives compared to the reference product. Areas covered: In this review, authors will review the literature on the clinical efficacy, safety and immunogenicity of current and future biosimilar infliximabs. Short- and medium-term data from real-life cohorts and from randomized-clinical trials in IBD demonstrated similar outcomes in terms of efficacy, safety and immunogenicity as the reference product for CT-P13. Switch data from the reference to the biosimilar product are also accumulating (including the NOR-SWITCH and the CT-P13 3.4 study). Expert opinion: The use of biosimilar infliximab in IBD is increasing worldwide. Its use may be associated with budget savings leading to better access to biological therapies and consequently improved health outcomes. Switching from the originator to a biosimilar in patients with IBD is acceptable, although scientific and clinical evidence is lacking regarding reverse switching, multiple switching, and cross-switching among biosimilars in IBD patients.

Modulating Vaccinia Virus Immunomodulators to Improve Immunological Memory

PubMed Central

Torres, Alice A.; Smith, Geoffrey L.

2018-01-01

The increasing frequency of monkeypox virus infections, new outbreaks of other zoonotic orthopoxviruses and concern about the re-emergence of smallpox have prompted research into developing antiviral drugs and better vaccines against these viruses. This article considers the genetic engineering of vaccinia virus (VACV) to enhance vaccine immunogenicity and safety. The virulence, immunogenicity and protective efficacy of VACV strains engineered to lack specific immunomodulatory or host range proteins are described. The ultimate goal is to develop safer and more immunogenic VACV vaccines that induce long-lasting immunological memory. PMID:29495547

A tetravalent virus-like particle vaccine designed to display domain III of dengue envelope proteins induces multi-serotype neutralizing antibodies in mice and macaques which confer protection against antibody dependent enhancement in AG129 mice

PubMed Central

Shukla, Rahul; Poddar, Ankur; Shanmugam, Rajgokul K.; White, Laura J.; Mattocks, Melissa M.; Raut, Rajendra; Perween, Ashiya; Tyagi, Poornima; de Silva, Aravinda M.; Bhaumik, Siddhartha K.; Kaja, Murali Krishna; Villinger, François; Ahmed, Rafi; Johnston, Robert E.; Khanna, Navin

2018-01-01

Background Dengue is one of the fastest spreading vector-borne diseases, caused by four antigenically distinct dengue viruses (DENVs). Antibodies against DENVs are responsible for both protection as well as pathogenesis. A vaccine that is safe for and efficacious in all people irrespective of their age and domicile is still an unmet need. It is becoming increasingly apparent that vaccine design must eliminate epitopes implicated in the induction of infection-enhancing antibodies. Methodology/principal findings We report a Pichia pastoris-expressed dengue immunogen, DSV4, based on DENV envelope protein domain III (EDIII), which contains well-characterized serotype-specific and cross-reactive epitopes. In natural infection, <10% of the total neutralizing antibody response is EDIII-directed. Yet, this is a functionally relevant domain which interacts with the host cell surface receptor. DSV4 was designed by in-frame fusion of EDIII of all four DENV serotypes and hepatitis B surface (S) antigen and co-expressed with unfused S antigen to form mosaic virus-like particles (VLPs). These VLPs displayed EDIIIs of all four DENV serotypes based on probing with a battery of serotype-specific anti-EDIII monoclonal antibodies. The DSV4 VLPs were highly immunogenic, inducing potent and durable neutralizing antibodies against all four DENV serotypes encompassing multiple genotypes, in mice and macaques. DSV4-induced murine antibodies suppressed viremia in AG129 mice and conferred protection against lethal DENV-4 virus challenge. Further, neither murine nor macaque anti-DSV4 antibodies promoted mortality or inflammatory cytokine production when passively transferred and tested in an in vivo dengue disease enhancement model of AG129 mice. Conclusions/significance Directing the immune response to a non-immunodominant but functionally relevant serotype-specific dengue epitope of the four DENV serotypes, displayed on a VLP platform, can help minimize the risk of inducing disease-enhancing antibodies while eliciting effective tetravalent seroconversion. DSV4 has a significant potential to emerge as a safe, efficacious and inexpensive subunit dengue vaccine candidate. PMID:29309412

Immunogenicity and Protective Efficacy in Mice and Hamsters of a β-Propiolactone Inactivated Whole Virus SARS-CoV Vaccine

PubMed Central

Roberts, Anjeanette; Lamirande, Elaine W.; Vogel, Leatrice; Baras, Benoît; Goossens, Geneviève; Knott, Isabelle; Chen, Jun; Ward, Jerrold M.; Vassilev, Ventzislav

2010-01-01

Abstract The immunogenicity and efficacy of β-propiolactone (BPL) inactivated whole virion SARS-CoV (WI-SARS) vaccine was evaluated in BALB/c mice and golden Syrian hamsters. The vaccine preparation was tested with or without adjuvants. Adjuvant Systems AS01B and AS03A were selected and tested for their capacity to elicit high humoral and cellular immune responses to WI-SARS vaccine. We evaluated the effect of vaccine dose and each adjuvant on immunogenicity and efficacy in mice, and the effect of vaccine dose with or without the AS01B adjuvant on the immunogenicity and efficacy in hamsters. Efficacy was evaluated by challenge with wild-type virus at early and late time points (4 and 18 wk post-vaccination). A single dose of vaccine with or without adjuvant was poorly immunogenic in mice; a second dose resulted in a significant boost in antibody levels, even in the absence of adjuvant. The use of adjuvants resulted in higher antibody titers, with the AS01B-adjuvanted vaccine being slightly more immunogenic than the AS03A-adjuvanted vaccine. Two doses of WI-SARS with and without Adjuvant Systems were highly efficacious in mice. In hamsters, two doses of WI-SARS with and without AS01B were immunogenic, and two doses of 2 μg of WI-SARS with and without the adjuvant provided complete protection from early challenge. Although antibody titers had declined in all groups of vaccinated hamsters 18 wk after the second dose, the vaccinated hamsters were still partially protected from wild-type virus challenge. Vaccine with adjuvant provided better protection than non-adjuvanted WI-SARS vaccine at this later time point. Enhanced disease was not observed in the lungs or liver of hamsters following SARS-CoV challenge, regardless of the level of serum neutralizing antibodies. PMID:20883165

Immunogenicity and thermal stability of a combined vaccine against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases.

PubMed

Saydam, Manolya; Burkin, Karena; Care, Rory; Rigsby, Peter; Bolgiano, Barbara; Mawas, Fatme

2010-08-31

The immunogenicity, structure and stability of a combined conjugate vaccine against Haemophilus influenzae type b and meningococcal serogroup C (Hib/MenC) were investigated. A rat model for immunogenicity showed that antibody responses to Hib and MenC in the combined vaccine were similar to or higher than those of individual conjugates given alone, or concomitantly at separate sites. At elevated temperatures, the combination vaccine was slightly more stable than a monovalent Hib-TT vaccine, with respect to molecular size, which could be attributed to differences in the formulations. Following 5 weeks incubation at 56 degrees C, there was some dissociation of high molecular weight conjugate without significant loss of saccharide integrity; however, this did not significantly affect the vaccine immunogenicity, demonstrating the stability of this lyophilized vaccine. (c) 2010 Elsevier Ltd. All rights reserved.

Characterization and standardization of Sabin based inactivated polio vaccine: proposal for a new antigen unit for inactivated polio vaccines.

PubMed

Westdijk, Janny; Brugmans, Debbie; Martin, Javier; van't Oever, Aart; Bakker, Wilfried A M; Levels, Lonneke; Kersten, Gideon

2011-04-18

GMP-batches of Sabin-IPV were characterized for their antigenic and immunogenic properties. Antigenic fingerprints of Sabin-IPV reveal that the D-antigen unit is not a fixed amount of antigen but depends on antibody and assay type. Instead of the D-antigen unit we propose standardization of IPV based on a combination of protein amount for dose and D-antigenicity for quality of the vaccine. Although Sabin-IPV type 2 is less immunogenic than regular wild type IPV type 2, the immunogenicity (virus neutralizing titers) per microgram antigen for Sabin-IPV type 2 is in the same order as for wild type serotypes 1 and 3. The latter observations are in line with data from human trials. This suggests that a higher dose of Sabin-IPV type 2 to compensate for the lower rat immunogenicity may not be necessary. Copyright © 2011 Elsevier Ltd. All rights reserved.

From the bench to clinical practice: understanding the challenges and uncertainties in immunogenicity testing for biopharmaceuticals

PubMed Central

Gunn, G. R.; Sealey, D. C. F.; Jamali, F.; Meibohm, B.; Ghosh, S.

2016-01-01

Summary Unlike conventional chemical drugs where immunogenicity typically does not occur, the development of anti‐drug antibodies following treatment with biologics has led to concerns about their impact on clinical safety and efficacy. Hence the elucidation of the immunogenicity of biologics is required for drug approval by health regulatory authorities worldwide. Published ADA ‘incidence’ rates can vary greatly between same‐class products and different patient populations. Such differences are due to disparate bioanalytical methods and interpretation approaches, as well as a plethora of product‐specific and patient‐specific factors that are not fully understood. Therefore, the incidence of ADA and their association with clinical consequences cannot be generalized across products. In this context, the intent of this review article is to discuss the complex nature of ADA and key nuances of the methodologies used for immunogenicity assessments, and to dispel some fallacies and myths. PMID:26597698

The safety and immunogenicity of influenza vaccine in children with asthma in Mexico.

PubMed

Pedroza, Alvaro; Huerta, José G; Garcia, Maria de la Luz; Rojas, Arsheli; López-Martínez, Irma; Penagos, Martín; Franco-Paredes, Carlos; Deroche, Christele; Mascareñas, Cesar

2009-07-01

The morbidity and mortality associated with influenza is substantial in children with asthma. There are no available data on the safety and immunogenicity of influenza vaccine in children with asthma in Latin America. Furthermore, it is unclear if influenza vaccination may cause asthma exacerbations. We conducted a placebo-controlled trial to investigate the safety and immunogenicity of an inactivated trivalent split virus influenza vaccine in children with asthma in Mexico. We also measured the impact of influenza vaccination on pulmonary function tests in this population. The inactivated influenza vaccine was immunogenic and safe in terms of local and systemic side effects compared to placebo. We observed no significant impact on pulmonary function tests among vaccine recipients. Given the significant morbidity associated with influenza in children, strategies to promote increased influenza vaccination coverage in this high-risk group in Latin America and elsewhere are urgently needed.

Mosaic HIV envelope immunogenic polypeptides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon

Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in amore » subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.« less

Addressing the Immunogenicity of the Cargo and of the Targeting Antibodies with a Focus on Deimmunized Bacterial Toxins and on Antibody-Targeted Human Effector Proteins

PubMed Central

Grinberg, Yehudit; Benhar, Itai

2017-01-01

Third-generation immunotoxins are composed of a human, or humanized, targeting moiety, usually a monoclonal antibody or an antibody fragment, and a non-human effector molecule. Due to the non-human origin of the cytotoxic domain, these molecules stimulate potent anti-drug immune responses, which limit treatment options. Efforts are made to deimmunize such immunotoxins or to combine treatment with immunosuppression. An alternative approach is using the so-called “human cytotoxic fusion proteins”, in which antibodies are used to target human effector proteins. Here, we present three relevant approaches for reducing the immunogenicity of antibody-targeted protein therapeutics: (1) reducing the immunogenicity of the bacterial toxin, (2) fusing human cytokines to antibodies to generate immunocytokines and (3) addressing the immunogenicity of the targeting antibodies. PMID:28574434

Structural mimicry of O-antigen by a peptide revealed in a complex with an antibody raised against Shigella flexneri serotype 2a.

PubMed

Theillet, François-Xavier; Saul, Frederick A; Vulliez-Le Normand, Brigitte; Hoos, Sylviane; Felici, Franco; Weintraub, Andrej; Mulard, Laurence A; Phalipon, Armelle; Delepierre, Muriel; Bentley, Graham A

2009-05-15

The use of carbohydrate-mimicking peptides to induce immune responses against surface polysaccharides of pathogenic bacteria offers a novel approach to vaccine development. Factors governing antigenic and immunogenic mimicry, however, are complex and poorly understood. We have addressed this question using the anti-lipopolysaccharide monoclonal antibody F22-4, which was raised against Shigella flexneri serotype 2a and shown to protect against homologous infection in a mouse model. In a previous crystallographic study, we described F22-4 in complex with two synthetic fragments of the O-antigen, the serotype-specific saccharide moiety of lipopolysaccharide. Here, we present a crystallographic and NMR study of the interaction of F22-4 with a dodecapeptide selected by phage display using the monoclonal antibody. Like the synthetic decasaccharide, the peptide binds to F22-4 with micromolar affinity. Although the peptide and decasaccharide use very similar regions of the antigen-binding site, indicating good antigenic mimicry, immunogenic mimicry by the peptide was not observed. The F22-4-antigen interaction is significantly more hydrophobic with the peptide than with oligosaccharides; nonetheless, all hydrogen bonds formed between the peptide and F22-4 have equivalents in the oligosaccharide complex. Two bridging water molecules are also in common, adding to partial structural mimicry. Whereas the bound peptide is entirely helical, its structure in solution, as shown by NMR, is helical in the central region only. Moreover, docking the NMR structure into the antigen-binding site shows that steric hindrance would occur, revealing poor complementarity between the major solution conformation and the antibody that could contribute to the absence of immunogenic mimicry.

Pre-clinical antigenicity studies of an innovative multivalent vaccine for human visceral leishmaniasis

PubMed Central

Cecílio, Pedro; Pérez-Cabezas, Begoña; Fernández, Laura; Moreno, Javier; Carrillo, Eugenia; Requena, José M.; Fichera, Epifanio; Reed, Steven G.; Coler, Rhea N.; Kamhawi, Shaden; Oliveira, Fabiano; Valenzuela, Jesus G.; Gradoni, Luigi; Glueck, Reinhard; Gupta, Gaurav

2017-01-01

The notion that previous infection by Leishmania spp. in endemic areas leads to robust anti-Leishmania immunity, supports vaccination as a potentially effective approach to prevent disease development. Nevertheless, to date there is no vaccine available for human leishmaniasis. We optimized and assessed in vivo the safety and immunogenicity of an innovative vaccine candidate against human visceral leishmaniasis (VL), consisting of Virus-Like Particles (VLP) loaded with three different recombinant proteins (LJL143 from Lutzomyia longipalpis saliva as the vector-derived (VD) component, and KMP11 and LeishF3+, as parasite-derived (PD) antigens) and adjuvanted with GLA-SE, a TLR4 agonist. No apparent adverse reactions were observed during the experimental time-frame, which together with the normal hematological parameters detected seems to point to the safety of the formulation. Furthermore, measurements of antigen-specific cellular and humoral responses, generally higher in immunized versus control groups, confirmed the immunogenicity of the vaccine formulation. Interestingly, the immune responses against the VD protein were reproducibly more robust than those elicited against leishmanial antigens, and were apparently not caused by immunodominance of the VD antigen. Remarkably, priming with the VD protein alone and boosting with the complete vaccine candidate contributed towards an increase of the immune responses to the PD antigens, assessed in the form of increased ex vivo CD4+ and CD8+ T cell proliferation against both the PD antigens and total Leishmania antigen (TLA). Overall, our immunogenicity data indicate that this innovative vaccine formulation represents a promising anti-Leishmania vaccine whose efficacy deserves to be tested in the context of the “natural infection”. PMID:29176865

Immunogenicity of hydrolysate formulas in children (part 1). Analysis of 202 reactions.

PubMed

Cantani, A; Micera, M

2000-01-01

Cow's milk protein hydrolyzed formulas appeared in the 1940s with the aim of decreasing or eliminating the allergenicity of cow's milk proteins, in addition to reducing the risk of sensitization. In recent years, the so-called "hypoallergenic" formulas have been developed. The use of such hydrolyzed formulas is based on the premise that predigested proteins, when fed as amino acids and peptides, provide nutrients in a nonantigenic form. Thus, protein hydrolyzed formulas have been classified as hypoallergenic. These formulas are processed by heat and enzymatic hydrolysis, and the conformational and sequential structures are more or less changed. The formulas contain peptides of lower molecular weight than the native protein source, which are thought to be less immunogenic. Hydrolyzed formulas appear to be nutritionally adequate and infants generally gain weight until they refuse the formula because of its bad taste. However, caution should be taken when such formulas are given for prolonged periods since no data are available on nutritional assessment of infants exclusively fed hydrolyzed formulas for several months. In this paper we report and discuss more than 202 reactions to different hydrolyzed formulas, including cases of anaphylactic shock and apparent life-threatening events. The cross-reactivity between different hydrolyzed formulas and cow's milk proteins, and the potential immunogenicity of such formulas are discussed. We conclude that none of the hydrolyzed formulas are nonallergenic, both for allergic children and for high-risk babies. Moreover, we suggest that double-blind placebo-controlled food challenge studies in larger cohorts of babies evaluated with well-defined and well-validated diagnostic methods may establish a more reliable prevalence of allergy to hydrolyzed formulas.

Immunogenicity of a live-attenuated human rotavirus RIX4414 vaccine with or without buffering agent.

PubMed

Kerdpanich, Angkool; Chokephaibulkit, Kulkanya; Watanaveeradej, Veerachai; Vanprapar, Nirun; Simasathien, Sriluck; Phavichitr, Nopaorn; Bock, Hans L; Damaso, Silvia; Hutagalung, Yanee; Han, Htay-Htay

2010-03-26

The lyophilized form of the human rotavirus RIX4414 vaccine (Rotarix()) is usually reconstituted with a liquid calcium carbonate (CaCO(3)) buffer and administered orally. However, errors in the reconstitution could occur (e.g. reconstituted with water instead of CaCO(3) buffer) or the buffer might be temporarily unavailable in few instances. This study was conducted to evaluate the immunogenicity of the RIX4414 vaccine if the vaccine was reconstituted with other agents (e.g., water) instead of CaCO(3) buffer. There was no statistical difference detected between RIX4414 vaccine reconstituted with buffer or water in vaccine take or in seroconversion rate. The anti-rotavirus Immunoglobulin A (IgA) seroconversion rate 2 months post-Dose 2 was 84.7% (95% CI: 78.1-90.0) for the group with buffer and 78.6% (95% CI: 71.2-84.8) for the group with water. Solicited and unsolicited symptoms reported were similar across groups. No vaccine related serious adverse events (SAEs) were reported. Healthy infants aged 6-12 weeks, received two oral doses of the RIX4414 vaccine/placebo, reconstituted either with injectable water or CaCO(3) buffer according to a 0, 2 month schedule. Seroconversion rates in terms of anti-RV IgA antibody levels (cut off: >/=20 U/ml by ELISA) and vaccine take were calculated 2 months post-Dose 2. Solicited and unsolicited symptoms reported during the 15- and 31-day follow-up period after each dose and SAE s reported during the entire study period were recorded. Administration of RIX4414 vaccine in the absence of CaCO(3) buffer was shown to be well tolerated and immunogenic in Thai infants.

Packaging and Prefusion Stabilization Separately and Additively Increase the Quantity and Quality of Respiratory Syncytial Virus (RSV)-Neutralizing Antibodies Induced by an RSV Fusion Protein Expressed by a Parainfluenza Virus Vector.

PubMed

Liang, Bo; Ngwuta, Joan O; Herbert, Richard; Swerczek, Joanna; Dorward, David W; Amaro-Carambot, Emerito; Mackow, Natalie; Kabatova, Barbora; Lingemann, Matthias; Surman, Sonja; Yang, Lijuan; Chen, Man; Moin, Syed M; Kumar, Azad; McLellan, Jason S; Kwong, Peter D; Graham, Barney S; Schaap-Nutt, Anne; Collins, Peter L; Munir, Shirin

2016-11-01

Human respiratory syncytial virus (RSV) and human parainfluenza virus type 3 (HPIV3) are major pediatric respiratory pathogens that lack vaccines. A chimeric bovine/human PIV3 (rB/HPIV3) virus expressing the unmodified, wild-type (wt) RSV fusion (F) protein from an added gene was previously evaluated in seronegative children as a bivalent intranasal RSV/HPIV3 vaccine, and it was well tolerated but insufficiently immunogenic for RSV F. We recently showed that rB/HPIV3 expressing a partially stabilized prefusion form (pre-F) of RSV F efficiently induced "high-quality" RSV-neutralizing antibodies, defined as antibodies that neutralize RSV in vitro without added complement (B. Liang et al., J Virol 89:9499-9510, 2015, doi:10.1128/JVI.01373-15). In the present study, we modified RSV F by replacing its cytoplasmic tail (CT) domain or its CT and transmembrane (TM) domains (TMCT) with counterparts from BPIV3 F, with or without pre-F stabilization. This resulted in RSV F being packaged in the rB/HPIV3 particle with an efficiency similar to that of RSV particles. Enhanced packaging was substantially attenuating in hamsters (10- to 100-fold) and rhesus monkeys (100- to 1,000-fold). Nonetheless, TMCT-directed packaging substantially increased the titers of high-quality RSV-neutralizing serum antibodies in hamsters. In rhesus monkeys, a strongly additive immunogenic effect of packaging and pre-F stabilization was observed, as demonstrated by 8- and 30-fold increases of RSV-neutralizing serum antibody titers in the presence and absence of added complement, respectively, compared to pre-F stabilization alone. Analysis of vaccine-induced F-specific antibodies by binding assays indicated that packaging conferred substantial stabilization of RSV F in the pre-F conformation. This provides an improved version of this well-tolerated RSV/HPIV3 vaccine candidate, with potently improved immunogenicity, which can be returned to clinical trials. Human respiratory syncytial virus (RSV) and human parainfluenza virus type 3 (HPIV3) are major viral agents of acute pediatric bronchiolitis and pneumonia worldwide that lack vaccines. A bivalent intranasal RSV/HPIV3 vaccine candidate consisting of a chimeric bovine/human PIV3 (rB/HPIV3) strain expressing the RSV fusion (F) protein was previously shown to be well tolerated by seronegative children but was insufficiently immunogenic for RSV F. In the present study, the RSV F protein was engineered to be packaged efficiently into vaccine virus particles. This resulted in a significantly enhanced quantity and quality of RSV-neutralizing antibodies in hamsters and nonhuman primates. In nonhuman primates, this effect was strongly additive to the previously described stabilization of the prefusion conformation of the F protein. The improved immunogenicity of RSV F by packaging appeared to involve prefusion stabilization. These findings provide a potently more immunogenic version of this well-tolerated vaccine candidate and should be applicable to other vectored vaccines. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Packaging and Prefusion Stabilization Separately and Additively Increase the Quantity and Quality of Respiratory Syncytial Virus (RSV)-Neutralizing Antibodies Induced by an RSV Fusion Protein Expressed by a Parainfluenza Virus Vector

PubMed Central

Liang, Bo; Ngwuta, Joan O.; Herbert, Richard; Swerczek, Joanna; Dorward, David W.; Amaro-Carambot, Emerito; Mackow, Natalie; Kabatova, Barbora; Lingemann, Matthias; Surman, Sonja; Yang, Lijuan; Chen, Man; Moin, Syed M.; Kumar, Azad; McLellan, Jason S.; Kwong, Peter D.; Graham, Barney S.; Schaap-Nutt, Anne; Collins, Peter L.

2016-01-01

ABSTRACT Human respiratory syncytial virus (RSV) and human parainfluenza virus type 3 (HPIV3) are major pediatric respiratory pathogens that lack vaccines. A chimeric bovine/human PIV3 (rB/HPIV3) virus expressing the unmodified, wild-type (wt) RSV fusion (F) protein from an added gene was previously evaluated in seronegative children as a bivalent intranasal RSV/HPIV3 vaccine, and it was well tolerated but insufficiently immunogenic for RSV F. We recently showed that rB/HPIV3 expressing a partially stabilized prefusion form (pre-F) of RSV F efficiently induced “high-quality” RSV-neutralizing antibodies, defined as antibodies that neutralize RSV in vitro without added complement (B. Liang et al., J Virol 89:9499–9510, 2015, doi:10.1128/JVI.01373-15). In the present study, we modified RSV F by replacing its cytoplasmic tail (CT) domain or its CT and transmembrane (TM) domains (TMCT) with counterparts from BPIV3 F, with or without pre-F stabilization. This resulted in RSV F being packaged in the rB/HPIV3 particle with an efficiency similar to that of RSV particles. Enhanced packaging was substantially attenuating in hamsters (10- to 100-fold) and rhesus monkeys (100- to 1,000-fold). Nonetheless, TMCT-directed packaging substantially increased the titers of high-quality RSV-neutralizing serum antibodies in hamsters. In rhesus monkeys, a strongly additive immunogenic effect of packaging and pre-F stabilization was observed, as demonstrated by 8- and 30-fold increases of RSV-neutralizing serum antibody titers in the presence and absence of added complement, respectively, compared to pre-F stabilization alone. Analysis of vaccine-induced F-specific antibodies by binding assays indicated that packaging conferred substantial stabilization of RSV F in the pre-F conformation. This provides an improved version of this well-tolerated RSV/HPIV3 vaccine candidate, with potently improved immunogenicity, which can be returned to clinical trials. IMPORTANCE Human respiratory syncytial virus (RSV) and human parainfluenza virus type 3 (HPIV3) are major viral agents of acute pediatric bronchiolitis and pneumonia worldwide that lack vaccines. A bivalent intranasal RSV/HPIV3 vaccine candidate consisting of a chimeric bovine/human PIV3 (rB/HPIV3) strain expressing the RSV fusion (F) protein was previously shown to be well tolerated by seronegative children but was insufficiently immunogenic for RSV F. In the present study, the RSV F protein was engineered to be packaged efficiently into vaccine virus particles. This resulted in a significantly enhanced quantity and quality of RSV-neutralizing antibodies in hamsters and nonhuman primates. In nonhuman primates, this effect was strongly additive to the previously described stabilization of the prefusion conformation of the F protein. The improved immunogenicity of RSV F by packaging appeared to involve prefusion stabilization. These findings provide a potently more immunogenic version of this well-tolerated vaccine candidate and should be applicable to other vectored vaccines. PMID:27581977

Non-plaque-forming virions of Modified Vaccinia virus Ankara express viral genes.

PubMed

Lülf, Anna-Theresa; Freudenstein, Astrid; Marr, Lisa; Sutter, Gerd; Volz, Asisa

2016-12-01

In cell culture infections with vaccinia virus the number of counted virus particles is substantially higher than the number of plaques obtained by titration. We found that standard vaccine preparations of recombinant Modified Vaccinia virus Ankara produce only about 20-30% plaque-forming virions in fully permissive cell cultures. To evaluate the biological activity of the non-plaque-forming particles, we generated recombinant viruses expressing fluorescent reporter proteins under transcriptional control of specific viral early and late promoters. Live cell imaging and automated counting by fluorescent microscopy indicated that virtually all virus particles can enter cells and switch on viral gene expression. Although most of the non-plaque-forming infections are arrested at the level of viral early gene expression, we detected activation of late viral transcription in 10-20% of single infected cells. Thus, non-plaque-forming particles are biologically active, and likely contribute to the immunogenicity of vaccinia virus vaccines. Copyright © 2016 Elsevier Inc. All rights reserved.

Silencing of Endogenous IL-10 in Human Dendritic Cells Leads to the Generation of an Improved CTL Response Against Human Melanoma Associated Antigenic Epitope, MART-127−35

PubMed Central

Chhabra, Arvind; Chakraborty, Nityo G.; Mukherji, Bijay

2008-01-01

Dendritic cells (DC) present antigenic epitopes to and activate T cells. They also polarize the ensuing T cell response to Th1 or Th2 type response, depending on their cytokine production profile. For example, IL-12 producing DC generate Th1 type T cell response whereas IL-10 producing DC is usually tolerogenic. Different strategies -- such as the use of cytokines and anti-cytokine antibodies, dominant negative forms of protein, anti-sense RNA etc. -- have been employed to influence the cytokine synthetic profile of DC as well as to make DC more immunogenic. Utilizing GFP expressing recombinant adenoviruses in association with lipid-mediated transfection of siRNA, we have silenced the endogenous IL-10 gene in DC. We show that IL-10 gene silenced DC produce more IL-12 and also generates a better cytolytic T cell response against the human melanoma associated epitope, MART-127−35, in-vitro. We also show that the GFP expressing adenoviral vector can be used to optimize the parameters for siRNA delivery in primary cells and show that RNA interference methodology can efficiently knock-down virus encoded genes transcribed at very high multiplicity of infection in DC. PMID:18249038

Isolation and quantification of Quillaja saponaria Molina saponins and lipids in iscom-matrix and iscoms.

PubMed

Behboudi, S; Morein, B; Rönnberg, B

1995-12-01

In the iscom, multiple copies of antigen are attached by hydrophobic interaction to a matrix which is built up by Quillaja triterpenoid saponins and lipids. Thus, the iscom presents antigen in multimeric form in a small particle with a built-in adjuvant resulting in a highly immunogenic antigen formulation. We have designed a chloroform-methanol-water extraction procedure to isolate the triterpenoid saponins and lipids incorporated into iscom-matrix and iscoms. The triterpenoids in the triterpenoid phase were quantitated using orcinol sulfuric acid detecting their carbohydrate chains and by HPLC. The cholesterol and phosphatidylcholine in the lipid phase were quantitated by HPLC and a commercial colorimetric method for the cholesterol. The quantitative methods showed an almost total separation and recovery of triterpenoids and lipids in their respective phases, while protein was detected in all phases after extraction. The protein content was determined by the method of Lowry and by amino acid analysis. Amino acid analysis was shown to be the reliable method of the two to quantitate proteins in iscoms. In conclusion, simple, reproducible and efficient procedures have been designed to isolate and quantitate the triterpenoids and lipids added for preparation of iscom-matrix and iscoms. The procedures described should also be useful to adequately define constituents in prospective vaccines.

Low immunogenicity of allogeneic human umbilical cord blood-derived mesenchymal stem cells in vitro and in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Miyoung; Jeong, Sang Young; Ha, Jueun

2014-04-18

Highlights: • hUCB-MSCs maintained low immunogenicity even after immune challenge in vitro. • Humanized NSG mice were established using human UCB CD34+ cells. • Repeated intravenous hUCB-MSC injection into mice did not lead to immune responses and adverse events. • Allogeneic hUCB-MSCs maintained low immunogenicity in vitro and in vivo. - Abstract: Evaluation of the immunogenicity of human mesenchymal stem cells (MSCs) in an allogeneic setting during therapy has been hampered by lack of suitable models due to technical and ethical limitations. Here, we show that allogeneic human umbilical cord blood derived-MSCs (hUCB-MSCs) maintained low immunogenicity even after immune challengemore » in vitro. To confirm these properties in vivo, a humanized mouse model was established by injecting isolated hUCB-derived CD34+ cells intravenously into immunocompromised NOD/SCID IL2γnull (NSG) mice. After repeated intravenous injection of human peripheral blood mononuclear cells (hPBMCs) or MRC5 cells into these mice, immunological alterations including T cell proliferation and increased IFN-γ, TNF-α, and human IgG levels, were observed. In contrast, hUCB-MSC injection did not elicit these responses. While lymphocyte infiltration in the lung and small intestine and reduced survival rates were observed after hPBMC or MRC5 transplantation, no adverse events were observed following hUCB-MSC introduction. In conclusion, our data suggest that allogeneic hUCB-MSCs have low immunogenicity in vitro and in vivo, and are therefore “immunologically safe” for use in allogeneic clinical applications.« less

Breadth of neutralizing antibodies elicited by stable, homogeneous clade A and clade C HIV-1 gp140 envelope trimers in guinea pigs.

PubMed

Nkolola, Joseph P; Peng, Hanqin; Settembre, Ethan C; Freeman, Michael; Grandpre, Lauren E; Devoy, Colleen; Lynch, Diana M; La Porte, Annalena; Simmons, Nathaniel L; Bradley, Ritu; Montefiori, David C; Seaman, Michael S; Chen, Bing; Barouch, Dan H

2010-04-01

The native envelope (Env) spike on the surface of human immunodeficiency virus type 1 (HIV-1) is trimeric, and thus trimeric Env vaccine immunogens are currently being explored in preclinical immunogenicity studies. Key challenges have included the production and purification of biochemically homogeneous and stable trimers and the evaluation of these immunogens utilizing standardized virus panels for neutralization assays. Here we report the binding and neutralizing antibody (NAb) responses elicited by clade A (92UG037.8) and clade C (CZA97.012) Env gp140 trimer immunogens in guinea pigs. These trimers have been selected and engineered for optimal biochemical stability and have defined antigenic properties. Purified gp140 trimers with Ribi adjuvant elicited potent, cross-clade NAb responses against tier 1 viruses as well as detectable but low-titer NAb responses against select tier 2 viruses from clades A, B, and C. In particular, the clade C trimer elicited NAbs that neutralized 27%, 20%, and 47% of tier 2 viruses from clades A, B, and C, respectively. Heterologous DNA prime, protein boost as well as DNA prime, recombinant adenovirus boost regimens expressing these antigens, however, did not result in an increased magnitude or breadth of NAb responses in this system. These data demonstrate the immunogenicity of stable, homogeneous clade A and clade C gp140 trimers and exemplify the utility of standardized tier 1 and tier 2 virus panels for assessing the NAb responses of candidate HIV-1 Env immunogens.

Immunogenic Activity of a Ribosomal Fraction Obtained from Mycobacterium tuberculosis

PubMed Central

Youmans, Anne S.; Youmans, Guy P.

1965-01-01

Youmans, Anne S. (Northwestern University Medical School, Chicago, Ill.), and Guy P. Youmans. Immunogenic activity of a ribosomal fraction obtained from Mycobacterium tuberculosis. J. Bacteriol. 89:1291–1298. 1965.—The highly immunogenic particulate fraction obtained from mechanically ruptured cells of the H37Ra strain of Mycobacterium tuberculosis was suspended and centrifuged at 20,360 × g. The supernatant liquid from this centrifugation was centrifuged at 56,550 × g to remove the larger particles, and the supernatant liquid from this was centrifuged at 144,000 × g to obtain a ribosomal fraction. The sediments from the first two centrifugations were highly immunogenic, but the ribosomal fraction showed only slight capacity to immunize mice. However, when the ribosomal fraction was mixed with Freund's incomplete adjuvant, the immunogenic activity was equivalent to the particulate fraction from which it was prepared. To test the hypothesis that some membranous substance in the particulate fraction was acting as an adjuvant for the smaller particles in the ribosomal fraction, portions of the particulate fraction were treated separately with each of the membrane-disrupting agents, sodium deoxycholate, sodium lauryl sulfate, and 1 m sodium chloride. The treated materials were then centrifuged at 144,000 × g, and the sediments were tested for immunogenicity both with and without the addition of Freund's incomplete adjuvant. Without the adjuvant, the immunizing activities were very weak or absent; with the adjuvant, they were equivalent to that of the particulate fraction from which they were prepared. Other factors which have been found to damage or destroy membranes, such as freezing and thawing, and heat, also significantly decreased the immunogenic activity of the particulate fraction unless it was incorporated into Freund's incomplete adjuvant. The larger particles which sedimented at 56,550 × g were also treated with sodium lauryl sulfate and sodium chloride. Again, immunogenicity was greatly reduced but was fully restored by use of Freund's incomplete adjuvant. The data suggest, then, that the immunizing component of the particulate fraction is a substance (ribosomal?) which sediments at 144,000 × g, but for maximal immunizing activity a labile, possibly membranous, moiety of the mycobacterial cell, which has the properties of an adjuvant, is required. PMID:14293000

13-valent pneumococcal conjugate vaccine given with meningococcal C-tetanus toxoid conjugate and other routine pediatric vaccinations: immunogenicity and safety.

PubMed

Martinón-Torres, Federico; Gimenez-Sanchez, Francisco; Gurtman, Alejandra; Bernaola, Enrique; Diez-Domingo, Javier; Carmona, Alfonso; Sidhu, Mohinder; Sarkozy, Denise A; Gruber, William C; Emini, Emilio A; Scott, Daniel A

2012-04-01

As multiple vaccines are administered concomitantly during routine pediatric immunizations, it is important to ascertain the potential interference of any new vaccine on the immune response to the concomitantly administered vaccines. Immune responses to meningococcal serogroup C-tetanus toxoid conjugate vaccine (MnCC-TT) and the diphtheria and tetanus antigens in routine pediatric vaccines (diphtheria, tetanus, acellular pertussis-hepatitis B virus-inactivated poliovirus/Haemophilus influenza type b [DTaP-HBV-IPV/Hib] and DTaP-IPV+Hib) when given concomitantly with the 13-valent pneumococcal conjugate vaccine (PCV13) were compared with responses when given with PCV7. In addition, the immunogenicity and safety of PCV13 were assessed. Healthy infants were randomized to receive PCV13 or PCV7 (ages 2, 4, 6 and 15 months), concomitant with MnCC-TT (2, 4 and 15 months), DTaP-HBV-IPV/Hib (2, 4 and 6 months), and DTaP-IPV+Hib (15 months). Immune responses to MnCC-TT and to the diphtheria and tetanus antigens administered with PCV13 were noninferior to the responses observed when the vaccines were administered with PCV7; ≥96.6 (postinfant) and ≥99.4% (posttoddler) subjects achieved prespecified immune response levels to each antigen in each group. After the infant series, ≥93.0% of subjects receiving PCV13 achieved pneumococcal anticapsular immunoglobulin G concentrations ≥0.35 µg/mL for all serotypes except serotype 3 (86.2%), increasing to 98.1-100% for most serotypes (serotype 3: 93.6%) after the toddler dose. Local and systemic reactions were similar between groups. Immune responses to MnCC-TT, and other childhood vaccines (DTaP-HBV-IPV/Hib, DTaP-IPV+Hib) were noninferior when concomitantly administered with PCV13 compared with PCV7. PCV13 does not interfere with MnCC-TT. PCV13 is highly immunogenic with a favorable safety profile.

Immunogenicity of Mycobacterium leprae unique antigens in leprosy endemic populations in Asia and Africa.

PubMed

Bobosha, Kidist; Van Der Ploeg-Van Schip, Jolien J; Zewdie, Martha; Sapkota, Bishwa Raj; Hagge, Deanna A; Franken, Kees L M C; Inbiale, Wondmagegn; Aseffa, Abraham; Ottenhoff, Tom H M; Geluk, Annemieke

2011-12-01

Ongoing transmission of leprosy is evident from the stable disease incidence in high burden areas. Tools for early detection of Mycobacterium leprae (M. leprae) infection, particularly in sub-clinically infected individuals, are urgently required to reduce transmission. Following the sequencing of the M. leprae genome, many M. leprae-unique candidate proteins have been identified, several of which have been tested for induction of M. leprae specific T cell responses in different leprosy endemic areas. In this study, 21 M. leprae-unique proteins and 10 peptide pools covering the complete sequence of five M. leprae-unique proteins (ML0576, ML1989, ML1990, ML2283, and ML2567) were evaluated in 160 individuals in Nepal and Ethiopia. These included: tuberculoid and borderline tuberculoid (TT/BT), borderline borderline and borderline lepromatous (BB/BL) leprosy patients; healthy household contacts (HHC); tuberculosis (TB) patients and endemic controls (EC). Immunogenicity of the proteins was determined by IFN-gamma secretion via stimulation of PBMC in 6 days lymphocyte stimulation tests (LST) or in whole blood assays (WBA). In LST, BB/BL patients (40%) responded to ML0573 and ML1601 whereas ML1604 was most immunogenic in TT/BT (35%) and HHC (36%). Additionally, significant numbers of EC displayed IFN-gamma production in response to ML0573 (54%), ML1601 (50%) and ML1604 (54%). TB patients on the other hand, hardly responded to any of the proteins except for ML1989. Comparison of IFN-gamma responses to ML0121, ML0141 and ML0188 for TT/BT patients showed specific increase in diluted 6 days WBA compared to the undiluted 24 hours WBA, whereas EC showed a reduced response in the diluted WBA, which may indicate detection of disease-specific responses in the 6 days WBA. In summary, identification of multiple M. leprae proteins inducing M. leprae-specific T cell responses in groups at high risk of developing leprosy may contribute to improve early detection for M. leprae infection.

Peptide-loaded Langerhans cells, despite increased IL15 secretion and T cell activation in vitro, elicit anti-tumor T cell responses comparable to peptide-loaded monocyte-derived dendritic cells in vivo

PubMed Central

Romano, Emanuela; Rossi, Marco; Ratzinger, Gudrun; de Cos, Maria-Angeles; Chung, David J.; Panageas, Katherine S.; Wolchok, Jedd D.; Houghton, Alan N.; Chapman, Paul B.; Heller, Glenn; Yuan, Jianda; Young, James W.

2013-01-01

Purpose We compared the efficacy of human Langerhans cells (LCs) as tumor immunogens in vivo with monocyte-derived DCs (moDCs) and investigated how IL15 supports optimal DC-stimulated antitumor immunity. Experimental Design AJCC stage III/IV melanoma patients participated in this first clinical trial comparing melanoma peptide-pulsed LC with moDC vaccines (NCT00700167,www.ClinicalTrials.gov). Correlative studies evaluated mechanisms mediating IL15 support of DC-stimulated antitumor immunity. Results Both DC vaccines were safe and immunogenic for melanoma antigens. LC-based vaccines stimulated significantly greater tyrosinase-HLA-A*0201 tetramer reactivity than did moDC-based vaccines. The two DC subtypes were otherwise statistically comparable, in contrast to extensive prior data in vitro demonstrating LC superiority. LCs synthesize much more IL15 than moDCs and stimulate significantly more antigen-specific lymphocytes with a cytolytic IFN-gamma profile even without exogenous IL15. When supplemented by low dose IL15, instead of IL2, moDCs stimulate 5-6 logs more tumor antigen-specific effector memory T-cells (TEMRA) over 3-4 weeks in vitro. IL2 and IL15 can be synergistic in moDC stimulation of cytolytic T-cells. IL15 promotes T-cell expression of the antiapoptotic bcl-2 and inhibits candidate regulatory T-cell (Treg) expansion after DC stimulation, countering two effects of IL2 that do not foster tumor immunity. Conclusions MoDC-based vaccines will require exogenous IL15 to achieve clinical efficacy. Alternatively, LCs can couple the endogenous production of IL15 with potent T-cell stimulatory activity. Optimization of full length tumor antigen expression for processing into multiple immunogenic peptides for presentation by both class I and II MHC therefore merits emphasis to support more effective antitumor immunity stimulated by LCs. PMID:21355077

[Comparison of two different vaccination schemes against Hepatitis A and B in Mexican children and adolescents].

PubMed

González-Huezo, Ma Saraí; Sánchez-Avila, Francisco; García Mayol, Marcelino; Castro Narro, Graciela; Sixtos, Sara; Lisker-Melman, Mauricio; Kershenobich, David

2003-01-01

Development of multiple antigens in combined vaccines offers the advantages of reducing costs, increasing compliance and provides dual protection. Hepatitis A is an endemic disease in Mexico and hepatitis B, notwithstanding low prevalence, confers risk of progression to cirrhosis, hepatocellular carcinoma, and high medical costs in consequence. Determine immunogenicity and reactogenicity of a combined vaccine when compared with use of conventional vaccines simultaneously. The present study was a prospective, open, and randomized trial; 73 healthy children and adolescents were included, all with negative serologic markers. They were assigned to one of the following groups: Group 1, combined vaccine (n = 49) Twinrix (HAV 720 UE/HBV 20 micrograms), and group 2, separate vaccines (n = 24) Engerix B 20 micrograms/Havrix 720 UE. Both groups were given two-dose series at months 0 and 6. Geometric titles of antibody production (GMT) anti-HAV and anti-HBV were determined in months 1, 2, 6 and 7. Adverse reactions were registered during the study. No difference was observed between the two groups in age or gender. Immunogenicity anti-HAV: 100% of vaccines in both groups reached seroprotective levels (> or = 33 mUI/mL). Antibody titles in group 1 were three times higher than those in group 2 (9,696 mIU/mL vs. 3,940 mIU/mL [p = 0.003]) at the end of the study. Immunogenicity anti-HBV: All subjects in both groups reached seroprotective levels (> or = 10 mIU/mL) with similar antibody titles at the end of the study (group 1: 5,603 mIU/mL vs. group 2: 5,201 mIU/mL [p = 0.55 NS]). Reactogenicity: No serious adverse reactions were observed; main were local, and frequency and characteristics were similar in both groups. Seroprotective levels and reactogenicity obtained from use of a combined vaccine against hepatitis A/B are acceptable when compared with use of conventional vaccines administered separately.

Clinical trial in healthy malaria-naïve adults to evaluate the safety, tolerability, immunogenicity and efficacy of MuStDO5, a five-gene, sporozoite/hepatic stage Plasmodium falciparum DNA vaccine combined with escalating dose human GM-CSF DNA

PubMed Central

Richie, Thomas L.; Charoenvit, Yupin; Wang, Ruobing; Epstein, Judith E.; Hedstrom, Richard C.; Kumar, Sanjai; Luke, Thomas C.; Freilich, Daniel A.; Aguiar, Joao C.; Sacci, Jr., John B.; Sedegah, Martha; Nosek, Jr., Ronald A.; De La Vega, Patricia; Berzins, Mara P.; Majam, Victoria F.; Abot, Esteban N.; Ganeshan, Harini; Richie, Nancy O.; Banania, Jo Glenna; Baraceros, Maria Fe B.; Geter, Tanya G.; Mere, Robin; Bebris, Lolita; Limbach, Keith; Hickey, Bradley W.; Lanar, David E.; Ng, Jennifer; Shi, Meng; Hobart, Peter M.; Norman, Jon A.; Soisson, Lorraine A.; Hollingdale, Michael R.; Rogers, William O.; Doolan, Denise L.; Hoffman, Stephen L.

2012-01-01

When introduced in the 1990s, immunization with DNA plasmids was considered potentially revolutionary for vaccine development, particularly for vaccines intended to induce protective CD8 T cell responses against multiple antigens. We conducted, in 1997−1998, the first clinical trial in healthy humans of a DNA vaccine, a single plasmid encoding Plasmodium falciparum circumsporozoite protein (PfCSP), as an initial step toward developing a multi-antigen malaria vaccine targeting the liver stages of the parasite. As the next step, we conducted in 2000–2001 a clinical trial of a five-plasmid mixture called MuStDO5 encoding pre-erythrocytic antigens PfCSP, PfSSP2/TRAP, PfEXP1, PfLSA1 and PfLSA3. Thirty-two, malaria-naïve, adult volunteers were enrolled sequentially into four cohorts receiving a mixture of 500 μg of each plasmid plus escalating doses (0, 20, 100 or 500 μg) of a sixth plasmid encoding human granulocyte macrophage-colony stimulating factor (hGM-CSF). Three doses of each formulation were administered intramuscularly by needle-less jet injection at 0, 4 and 8 weeks, and each cohort had controlled human malaria infection administered by five mosquito bites 18 d later. The vaccine was safe and well-tolerated, inducing moderate antigen-specific, MHC-restricted T cell interferon-γ responses but no antibodies. Although no volunteers were protected, T cell responses were boosted post malaria challenge. This trial demonstrated the MuStDO5 DNA and hGM-CSF plasmids to be safe and modestly immunogenic for T cell responses. It also laid the foundation for priming with DNA plasmids and boosting with recombinant viruses, an approach known for nearly 15 y to enhance the immunogenicity and protective efficacy of DNA vaccines. PMID:23151451

Perspectives on Subcutaneous Route of Administration as an Immunogenicity Risk Factor for Therapeutic Proteins.

PubMed

Hamuro, Lora; Kijanka, Grzegorz; Kinderman, Francis; Kropshofer, Harald; Bu, De-Xiu; Zepeda, Monica; Jawa, Vibha

2017-10-01

An increasing number of therapeutic proteins are being developed for delivery through the subcutaneous (SC) route of administration. Relative to intravenous (IV) administration, the SC route offers more convenience to patients, flexibility in dosing, and potential to reduce health care costs. There is a perception that SC administration can pose a higher immunogenicity risk than IV administration for a given protein. To evaluate whether there is a difference in therapeutic protein immunogenicity associated with administration routes, a more detailed understanding of the interactions with the immune system by each route is needed. Few approved therapeutic proteins have available clinical immunogenicity data sets in the public domain that represent both IV and SC administration routes. This has prevented a direct comparison of the 2 routes of administration across a large sample size. Of the 6 marketed products where SC and IV route-related incidences of anti-drug antibody (ADA) were available, 4 were associated with higher immunogenicity incidence with SC. In other cases, there was no apparent difference between the SC and IV routes. Overall, the ADA incidence was low (<15%) with no impact on safety or efficacy. The challenges associated with identifying specific risk factors unique to SC administration are discussed. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Factors affecting the immunogenicity and potency of tetanus toxoid: implications for the elimination of neonatal and non-neonatal tetanus as public health problems.

PubMed Central

Dietz, V.; Galazka, A.; van Loon, F.; Cochi, S.

1997-01-01

An estimated 400,000 deaths occur annually from neonatal tetanus (NT). In 1989 WHO adopted the goal of eliminating NT as a public health problem worldwide. To achieve this, and to control non-neonatal tetanus (non-NT), WHO recommends that newborns be passively protected at birth by the antepartum administration of at least two doses of tetanus toxoid (TT) to their mothers and that all children subsequently receive at least three doses of diphtheria-tetanus-pertussis (DTP) vaccine. For this strategy to be effective, the TT used must be immunogenic. Potential factors that may affect TT immunogenicity need to be evaluated if NT is to be eliminated and if non-NT is to be controlled. Although data are conflicting, concurrent malarial infection may decrease the immune response to TT; however, malarial chemoprophylaxis may enhance the immune response. Malnutrition does not appear to affect immunogenicity; nevertheless, one study suggests that vitamin A deficiency is associated with an impaired immune response. Although it has been postulated that placental transfer of tetanus antibody is impaired in African women, a survey of the published literature suggests that this is not the case. Freezing TT has been shown to decrease its potency, but its impact on immunogenicity needs more evaluation. PMID:9141753

Reporting, Visualization, and Modeling of Immunogenicity Data to Assess Its Impact on Pharmacokinetics, Efficacy, and Safety of Monoclonal Antibodies.

PubMed

Passey, Chaitali; Suryawanshi, Satyendra; Sanghavi, Kinjal; Gupta, Manish

2018-02-26

The rapidly increasing number of therapeutic biologics in development has led to a growing recognition of the need for improvements in immunogenicity assessment. Published data are often inadequate to assess the impact of an antidrug antibody (ADA) on pharmacokinetics, safety, and efficacy, and enable a fully informed decision about patient management in the event of ADA development. The recent introduction of detailed regulatory guidance for industry should help address many past inadequacies in immunogenicity assessment. Nonetheless, careful analysis of gathered data and clear reporting of results are critical to a full understanding of the clinical relevance of ADAs, but have not been widely considered in published literature to date. Here, we review visualization and modeling of immunogenicity data. We present several relatively simple visualization techniques that can provide preliminary information about the kinetics and magnitude of ADA responses, and their impact on pharmacokinetics and clinical endpoints for a given therapeutic protein. We focus on individual sample- and patient-level data, which can be used to build a picture of any trends, thereby guiding analysis of the overall study population. We also discuss methods for modeling ADA data to investigate the impact of immunogenicity on pharmacokinetics, efficacy, and safety.

Subunit influenza vaccines produced from cell culture or in embryonated chicken eggs: comparison of safety, reactogenicity, and immunogenicity.

PubMed

Reisinger, Keith S; Block, Stanley L; Izu, Allen; Groth, Nicola; Holmes, Sandra J

2009-09-15

This study assessed the safety, reactogenicity, and immunogenicity of an injectable cell culture-derived influenza vaccine (CCIV), compared with those of an injectable egg-based trivalent inactivated influenza vaccine (TIV). Adult subjects (n = 613; 18 to <50 years of age) were randomized (1:1) to receive either CCIV or TIV. The safety and reactogenicity of the 2 vaccines were assessed on the basis of solicited indicators and other adverse events (AEs) within 7 days of vaccination. All serious AEs and those AEs resulting in withdrawal were recorded throughout the study. Antibody titers were determined by the hemagglutination inhibition assay, using egg- and cell-derived antigens. Immunogenicity was assessed on the basis of the ratio of postvaccination (day 22) geometric mean titers (GMTs) between the 2 vaccines, seroprotection rates, and seroconversion rates. There was no clinically relevant difference between the safety and reactogenicity profiles of the 2 vaccines. The immunogenicity of CCIV was demonstrated to be noninferior to that of TIV on the basis of the ratio of postvaccination GMTs between the 2 vaccines. GMTs, seroprotection rates, and seroconversion rates were comparable between the 2 vaccines. The safety, reactogenicity, and immunogenicity of the CCIV and the egg-based TIV are comparable.

Update on Janus Kinase Antagonists in Inflammatory Bowel Disease

PubMed Central

Boland, Brigid S.; Sandborn, William J.; Chang, John T.

2014-01-01

Janus kinase (JAK) inhibitors have emerged as a novel orally administered small molecule therapy for the treatment of ulcerative colitis and possibly Crohn’s disease. These molecules are designed to selectively target the activity of specific JAKs and offer a targeted mechanism of action without risk of immunogenicity. Based on data from clinical trials in rheumatoid arthritis and phase 2 studies in inflammatory bowel disease, tofacitinib and other JAK inhibitors are likely to become a new form of medical therapy for the treatment of inflammatory bowel disease. PMID:25110261

Oral immunization with a recombinant bacterial antigen produced in transgenic plants.

PubMed

Haq, T A; Mason, H S; Clements, J D; Arntzen, C J

1995-05-05

The binding subunit of Escherichia coli heat-labile enterotoxin (LT-B) is a highly active oral immunogen. Transgenic tobacco and potato plants were made with the use of genes encoding LT-B or an LT-B fusion protein with a microsomal retention sequence. The plants expressed the foreign peptides, both of which formed oligomers that bound the natural ligand. Mice immunized by gavage produced serum and gut mucosal anti-LT-B immunoglobulins that neutralized the enterotoxin in cell protection assays. Feeding mice fresh transgenic potato tubers also caused oral immunization.

Formulation and Stability of Solutions.

PubMed

Akers, Michael J

2016-01-01

Ready-to-use solutions are the most preferable and most common dosage forms for injectable and topical ophthalmic products. Drugs formulated as solution almost always have chemical and physical stability challenges as well as solubility limitations and the need to prevent inadvertent microbial contamination issues. The first in this series of articles took us through a discussion of optimizing the physical stability of solutions. This article concludes this series of articles with a discussion on foreign particles, protein aggregation, and immunogenicity; optimizing microbiological activity; and osmolality (tonicity) agents, and discusses how these challenges and issues are addressed.

The Dynamical Behaviors for a Class of Immunogenic Tumor Model with Delay

PubMed Central

Muthoni, Mutei Damaris; Pang, Jianhua

2017-01-01

This paper aims at studying the model proposed by Kuznetsov and Taylor in 1994. Inspired by Mayer et al., time delay is introduced in the general model. The dynamic behaviors of this model are studied, which include the existence and stability of the equilibria and Hopf bifurcation of the model with discrete delays. The properties of the bifurcated periodic solutions are studied by using the normal form on the center manifold. Numerical examples and simulations are given to illustrate the bifurcation analysis and the obtained results. PMID:29312457

Relationship between potential aggregation-prone regions and HLA-DR-binding T-cell immune epitopes: implications for rational design of novel and follow-on therapeutic antibodies.

PubMed

Kumar, Sandeep; Mitchell, Mark A; Rup, Bonita; Singh, Satish K

2012-08-01

Aggregation and unwanted immunogenicity are hurdles to avoid in successful commercial development of antibody-based therapeutics. In this article, the relationship between aggregation-prone regions (APRs), capable of forming cross-β motifs/amyloid fibrils, and major histocompatibility complex class II-restricted human leukocyte antigen (HLA)-DR-binding T-cell immune epitopes (TcIEs) is analyzed using amino acid sequences of 25 therapeutic antibodies, 55 TcIEs recognized by T-regulatory cells (tregitopes), 1000 randomly generated 15-residue-long peptides, 2257 human self-TcIEs (autoantigens), and 11 peptides in HLA-peptide cocrystal structures. Sequence analyses from these diverse sources consistently show a high level of correlation between APRs and TcIEs: approximately one-third of TcIEs contain APRs, but the majority of APRs occur within TcIE regions (TcIERs). Tregitopes also contain APRs. Most APR-containing TcIERs can bind multiple HLA-DR alleles, suggesting that aggregation-driven adverse immune responses could impact a broad segment of patient population. This article has identified common molecular sequence-structure loci that potentially contribute toward both manufacturability and safety profiles of the therapeutic antibodies, thereby laying a foundation for simultaneous optimization of these attributes in novel and follow-on candidates. Incidence of APRs within TcIERs is not special to biotherapeutics, self-TcIEs from human proteins, involved in various diseases, also contain predicted APRs and experimentally proven amyloid-fibril-forming peptide sequence portions. Copyright © 2012 Wiley Periodicals, Inc.

Glycosylation Benchmark Profile for HIV-1 Envelope Glycoprotein Production Based on Eleven Env Trimers

PubMed Central

Go, Eden P.; Ding, Haitao; Zhang, Shijian; Ringe, Rajesh P.; Nicely, Nathan; Hua, David; Steinbock, Robert T.; Golabek, Michael; Alin, James; Alam, S. Munir; Cupo, Albert; Haynes, Barton F.; Kappes, John C.; Moore, John P.; Sodroski, Joseph G.

2017-01-01

ABSTRACT HIV-1 envelope glycoprotein (Env) glycosylation is important because individual glycans are components of multiple broadly neutralizing antibody epitopes, while shielding other sites that might otherwise be immunogenic. The glycosylation on Env is influenced by a variety of factors, including the genotype of the protein, the cell line used for its expression, and the details of the construct design. Here, we used a mass spectrometry (MS)-based approach to map the complete glycosylation profile at every site in multiple HIV-1 Env trimers, accomplishing two goals. (i) We determined which glycosylation sites contain conserved glycan profiles across many trimeric Envs. (ii) We identified the variables that impact Env's glycosylation profile at sites with divergent glycosylation. Over half of the gp120 glycosylation sites on 11 different trimeric Envs have a conserved glycan profile, indicating that a native consensus glycosylation profile does indeed exist among trimers. We showed that some soluble gp120s and gp140s exhibit highly divergent glycosylation profiles compared to trimeric Env. We also assessed the impact of several variables on Env glycosylation: truncating the full-length Env; producing Env, instead of the more virologically relevant T lymphocytes, in CHO cells; and purifying Env with different chromatographic platforms, including nickel-nitrilotriacetic acid (Ni-NTA), 2G12, and PGT151 affinity. This report provides the first consensus glycosylation profile of Env trimers, which should serve as a useful benchmark for HIV-1 vaccine developers. This report also defines the sites where glycosylation may be impacted when Env trimers are truncated or produced in CHO cells. IMPORTANCE A protective HIV-1 vaccine will likely include a recombinant version of the viral envelope glycoprotein (Env). Env is highly glycosylated, and yet vaccine developers have lacked guidance on how to assess whether their immunogens have optimal glycosylation. The following important questions are still unanswered. (i) What is the “target” glycosylation profile, when the goal is to generate a natively glycosylated protein? (ii) What variables exert the greatest influence on Env glycosylation? We identified numerous sites on Env where the glycosylation profile does not deviate in 11 different Env trimers, and we investigated the impact on the divergent glycosylation profiles of changing the genotype of the Env sequence, the construct design, the purification method, and the producer cell type. The data presented here give vaccine developers a “glycosylation target” for their immunogens, and they show how protein production variables can impact Env glycosylation. PMID:28202756

The influence of different cucumariosides on immunogenicity of OmpF porin from Yersinia pseudotuberulosis as a model protein antigen of tubular immunostimulating complex

NASA Astrophysics Data System (ADS)

Sanina, N. M.; Chopenko, N. S.; Davydova, L. A.; Mazeika, A. N.; Portnyagina, O. Yu.; Kim, N. Yu.; Golotin, V. A.; Kostetsky, E. Y.; Shnyrov, V. L.

2017-09-01

Nanoparticulate tubular immunostimulating complex (TI-complex) is a novel promising adjuvant carrier of antigens allowing to create safe and effective vaccines of new generation. The adjuvant activity of TI-complexes based on monogalactosyldyacylglycerol (MGDG) from the sea alga Ulva lactuca and different triterpene glycosides cucumariosides (CDs) from marine invertebrate Cucumaria japonica and their fractions was studied to assess effects of different CDs on the immunogenicity of porin OmpF from Yersinia pseudotuberculosis (YOmpF). TI-complexes with cucumarioside A2-2 (CDA2-2) maximally stimulated anti-porin antibody production. Studies of protein intrinsic fluorescence showed that all CDs had a relaxing effect on the conformation of YOmpF, loosening peripheral region of protein and promoting exposure of the protein antigenic determinants to the water environment. The greatest immunostimulating effect of TI-complexes comprising CDA2-2 was accompanied by mild effect of this CD on the tertiary structure of protein antigen YOmpF, whereas cucumarioside E (CDE) and cucumarioside A2-4 (CDA2-4) caused especially sharp redistribution of spectral form of the YOmpF corresponding to the emission of an intrinsic protein fluorophore tryptophan.

Clostridium difficile carbohydrates: glucan in spores, PSII common antigen in cells, immunogenicity of PSII in swine and synthesis of a dual C. difficile-ETEC conjugate vaccine.

PubMed

Bertolo, Lisa; Boncheff, Alexander G; Ma, Zuchao; Chen, Yu-Han; Wakeford, Terra; Friendship, Robert M; Rosseau, Joyce; Weese, J Scott; Chu, Michele; Mallozzi, Michael; Vedantam, Gayatri; Monteiro, Mario A

2012-06-01

Clostridium difficile is responsible for severe diarrhea in humans that may cause death. Spores are the infectious form of C. difficile, which germinate into toxin-producing vegetative cells in response to bile acids. Recently, we discovered that C. difficile cells possess three complex polysaccharides (PSs), named PSI, PSII, and PSIII, in which PSI was only associated with a hypervirulent ribotype 027 strain, PSII was hypothesized to be a common antigen, and PSIII was a water-insoluble polymer. Here, we show that (i) C. difficile spores contain, at least in part, a D-glucan, (ii) PSI is not a ribotype 027-unique antigen, (iii) common antigen PSII may in part be present as a low molecular weight lipoteichoic acid, (iv) selective hydrolysis of PSII yields single PSII repeat units, (v) the glycosyl diester-phosphate linkage affords high flexibility to PSII, and (vi) that PSII is immunogenic in sows. Also, with the intent of creating a dual anti-diarrheal vaccine against C. difficile and enterotoxin Escherichia coli (ETEC) infections in humans, we describe the conjugation of PSII to the ETEC-associated LTB enterotoxin. Copyright © 2012 Elsevier Ltd. All rights reserved.

Early molecular correlates of adverse events following yellow fever vaccination

PubMed Central

Chan, Candice Y.Y.; Chan, Kuan Rong; Chua, Camillus J.H.; nur Hazirah, Sharifah; Ghosh, Sujoy; Ooi, Eng Eong; Low, Jenny G.

2017-01-01

The innate immune response shapes the development of adaptive immunity following infections and vaccination. However, it can also induce symptoms such as fever and myalgia, leading to the possibility that the molecular basis of immunogenicity and reactogenicity of vaccination are inseparably linked. To test this possibility, we used the yellow fever live-attenuated vaccine (YFLAV) as a model to study the molecular correlates of reactogenicity or adverse events (AEs). We analyzed the outcome of 68 adults who completed a YFLAV clinical trial, of which 43 (63.2%) reported systemic AEs. Through whole-genome profiling of blood collected before and after YFLAV dosing, we observed that activation of innate immune genes at day 1, but not day 3 after vaccination, was directly correlated with AEs. These findings contrast with the gene expression profile at day 3 that we and others have previously shown to be correlated with immunogenicity. We conclude that although the innate immune response is a double-edged sword, its expression that induces AEs is temporally distinct from that which engenders robust immunity. The use of genomic profiling thus provides molecular insights into the biology of AEs that potentially forms a basis for the development of safer vaccines. PMID:28978802

Evaluation of the immunogenicity and protective effects of a trivalent chimeric norovirus P particle immunogen displaying influenza HA2 from subtypes H1, H3 and B.

PubMed

Gong, Xin; Yin, He; Shi, Yuhua; He, Xiaoqiu; Yu, Yongjiao; Guan, Shanshan; Kuai, Ziyu; Haji, Nasteha M; Haji, Nafisa M; Kong, Wei; Shan, Yaming

2016-05-25

The ectodomain of the influenza A virus (IAV) hemagglutinin (HA) stem is highly conserved across strains and has shown promise as a universal influenza vaccine in a mouse model. In this study, potential B-cell epitopes were found through sequence alignment and epitope prediction in a stem fragment, HA2:90-105, which is highly conserved among virus subtypes H1, H3 and B. A norovirus (NoV) P particle platform was used to express the HA2:90-105 sequences from subtypes H1, H3 and B in loops 1, 2 and 3 of the protrusion (P) domain, respectively. Through mouse immunization and microneutralization assays, the immunogenicity and protective efficacy of the chimeric NoV P particle (trivalent HA2-PP) were tested against infection with three subtypes (H1N1, H3N2 and B) of IAV in Madin-Darby canine kidney cells. The protective efficacy of the trivalent HA2-PP was also evaluated preliminarily in vivo by virus challenge in the mouse model. The trivalent HA2-PP immunogen induced significant IgG antibody responses, which could be enhanced by a virus booster vaccination. Moreover, the trivalent HA2-PP immunogen also demonstrated in vitro neutralization of the H3 and B viruses, and in vivo protection against the H3 virus. Our results support the notion that a broadly protective vaccine approach using an HA2-based NoV P particle platform can provide cross-protection against challenge viruses of different IAV subtypes. The efficacy of the immunogen should be further enhanced for practicality, and a better understanding of the protective immune mechanism will be critical for the development of HA2-based multivalent vaccines.

Immunogenicity to poliovirus type 2 following two doses of fractional intradermal inactivated poliovirus vaccine: A novel dose sparing immunization schedule.

PubMed

Anand, Abhijeet; Molodecky, Natalie A; Pallansch, Mark A; Sutter, Roland W

2017-05-19

The polio eradication endgame strategic plan calls for the sequential removal of Sabin poliovirus serotypes from the trivalent oral poliovirus vaccine (tOPV), starting with type 2, and the introduction of ≥1 dose of inactivated poliovirus vaccine (IPV), to maintain an immunity base against poliovirus type 2. The global removal of oral poliovirus type 2 was successfully implemented in May 2016. However, IPV supply constraints has prevented introduction in 21 countries and led to complete stock-out in >20 countries. We conducted a literature review and contacted corresponding authors of recent studies with fractional-dose IPV (fIPV), one-fifth of intramuscular dose administered intradermally, to conduct additional type 2 immunogenicity analyses of two fIPV doses compared with one full-dose IPV. Four studies were identified that assessed immunogenicity of two fIPV doses compared to one full-dose IPV. Two fractional doses are more immunogenic than 1 full-dose, with type 2 seroconversion rates improving between absolute 19-42% (median: 37%, p<0.001) and relative increase of 53-125% (median: 82%), and antibody titer to type 2 increasing by 2-32-fold (median: 10-fold). Early age of administration and shorter intervals between doses were associated with lower immunogenicity. Overall, two fIPV doses are more immunogenic than a single full-dose, associated with significantly increased seroconversion rates and antibody titers. Two fIPV doses together use two-fifth of the vaccine compared to one full-dose IPV. In response to the current IPV shortage, a schedule of two fIPV doses at ages 6 and 14weekshas been endorsed by technical oversight committees and has been introduced in some affected countries. Copyright © 2017. Published by Elsevier Ltd.

Interference of Monovalent, Bivalent, and Trivalent Oral Poliovirus Vaccines on Monovalent Rotavirus Vaccine Immunogenicity in Rural Bangladesh

PubMed Central

Emperador, Devy M.; Velasquez, Daniel E.; Estivariz, Concepcion F.; Lopman, Ben; Jiang, Baoming; Parashar, Umesh; Anand, Abhijeet; Zaman, Khalequ

2016-01-01

Background Trivalent oral poliovirus vaccine (OPV) is known to interfere with monovalent rotavirus vaccine (RV1) immunogenicity. The interference caused by bivalent and monovalent OPV formulations, which will be increasingly used globally in coming years, has not been examined. We conducted a post hoc analysis to assess the effect of coadministration of different OPV formulations on RV1 immunogenicity. Methods Healthy infants in Matlab, Bangladesh, were randomized to receive 3 doses of monovalent OPV type 1 or bivalent OPV types 1 and 3 at either 6, 8, and 10 or 6, 10, and 14 weeks of age or trivalent OPV at 6, 10, and 14 weeks of age. All infants received 2 doses of RV1 at about 6 and 10 weeks of age. Concomitant administration was defined as RV1 and OPV given on the same day; staggered administration as RV1 and OPV given ≥1 day apart. Rotavirus seroconversion was defined as a 4-fold rise in immunoglobulin A titer from before the first RV1 dose to ≥3 weeks after the second RV1 dose. Results There were no significant differences in baseline RV1 immunogenicity among the 409 infants included in the final analysis. Infants who received RV1 and OPV concomitantly, regardless of OPV formulation, were less likely to seroconvert (47%; 95% confidence interval, 39%–54%) than those who received both vaccines staggered ≥1 day (63%; 57%–70%; P < .001). For staggered administration, we found no evidence that the interval between RV1 and OPV administration affected RV1 immunogenicity. Conclusions Coadministration of monovalent, bivalent, or trivalent OPV seems to lower RV1 immunogenicity. Clinical Trials Registration NCT01633216. PMID:26349548

Immunogenicity is not improved by increased antigen dose or booster dosing of seasonal influenza vaccine in a randomized trial of HIV infected adults.

PubMed

Cooper, Curtis; Thorne, Anona; Klein, Marina; Conway, Brian; Boivin, Guy; Haase, David; Shafran, Stephen; Zubyk, Wendy; Singer, Joel; Halperin, Scott; Walmsley, Sharon

2011-03-25

The risk of poor vaccine immunogenicity and more severe influenza disease in HIV necessitate strategies to improve vaccine efficacy. A randomized, multi-centered, controlled, vaccine trial with three parallel groups was conducted at 12 CIHR Canadian HIV Trials Network sites. Three dosing strategies were used in HIV infected adults (18 to 60 years): two standard doses over 28 days, two double doses over 28 days and a single standard dose of influenza vaccine, administered prior to the 2008 influenza season. A trivalent killed split non-adjuvanted influenza vaccine (Fluviral™) was used. Serum hemagglutinin inhibition (HAI) activity for the three influenza strains in the vaccine was measured to assess immunogenicity. 297 of 298 participants received at least one injection. Baseline CD4 (median 470 cells/µL) and HIV RNA (76% of patients with viral load <50 copies/mL) were similar between groups. 89% were on HAART. The overall immunogenicity of influenza vaccine across time points and the three influenza strains assessed was poor (Range HAI ≥ 40 =  31-58%). Double dose plus double dose booster slightly increased the proportion achieving HAI titre doubling from baseline for A/Brisbane and B/Florida at weeks 4, 8 and 20 compared to standard vaccine dose. Increased immunogenicity with increased antigen dose and booster dosing was most apparent in participants with unsuppressed HIV RNA at baseline. None of 8 serious adverse events were thought to be immunization-related. Even with increased antigen dose and booster dosing, non-adjuvanted influenza vaccine immunogenicity is poor in HIV infected individuals. Alternative influenza vaccines are required in this hyporesponsive population. ClinicalTrials.gov NCT00764998.

Immunogenicity of variable regions of hepatitis C virus proteins: selection and modification of peptide epitopes to assess hepatitis C virus genotypes by ELISA.

PubMed

Rodríguez-López, M; Riezu-Boj, J I; Ruiz, M; Berasain, C; Civeira, M P; Prieto, J; Borrás-Cuesta, F

1999-03-01

The immunogenicity of variable regions of hepatitis C virus (HCV) proteins was studied by ELISA by using 543 synthetic peptides from 120 variable regions and 90 sera from HCV-infected patients. Some regions from certain genotypes were less immunogenic, or even non-immunogenic, compared with their equivalents in other genotypes. However, the mean recognition of all peptides from genotypes 1a, 1b and 3 by sera infected with genotypes 1a, 1b and 3, respectively, showed no significant differences, suggesting a similar overall immunogenicity of variable regions from these genotypes. Proteins NS4a, NS4b and NS5a were found to be the most immunogenic. Recognition of individual peptides by the sera of infected patients showed that the humoral response against HCV is patient-dependent. The work shows that 15-mer peptides may encompass several B-cell epitopes. These epitopes may lie in slightly different positions in different genotypes. Thirty-one percent of the 543 peptides were recognized by some of the 35 healthy donors. This may be a reflection of the large number of antigens to which they had been exposed, but it may also reflect a strategy of HCV to respond to immune pressure. After selection and modification, a set of 40 peptides was used to assess genotypes 1a, 1b, 1, 2 and 3 in the sera of HCV-infected patients, with sensitivities of 34.1, 48.5, 68.8, 58.3 and 48.9% and specificities of 100, 99.1, 97.1, 99.5 and 99%, respectively. The overall sensitivity and specificity for the assessment of genotypes 1, 2 and 3 were 64 and 98%, respectively.

Immunologically active peptides capable of inducing immunization against malaria and genes encoding therefor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dame, J.B.; Williams, J.L.; McCutchan, T.F.

An antimalarial immunogenic stimulant is described comprising an immunogenic carrier and a peptide sequence of between 2 and 1000 consecutive repeats of a sequence Asn-X-Y-Pro, wherein X is Ala or Val and Y is Asn or Asp.

New FDA draft guidance on immunogenicity.

PubMed

Parenky, Ashwin; Myler, Heather; Amaravadi, Lakshmi; Bechtold-Peters, Karoline; Rosenberg, Amy; Kirshner, Susan; Quarmby, Valerie

2014-05-01

A "Late Breaking" session was held on May 20 at the 2013 American Association of Pharmaceutical Scientists-National Biotech Conference (AAPS-NBC) to discuss the US Food and Drug Administration's (FDA) 2013 draft guidance on Immunogenicity Assessment for Therapeutic Protein Products. The session was initiated by a presentation from the FDA which highlighted several key aspects of the 2013 draft guidance pertaining to immunogenicity risk, the potential impact on patient safety and product efficacy, and risk mitigation. This was followed by an open discussion on the draft guidance which enabled delegates from biopharmaceutical companies to engage the FDA on topics that had emerged from their review of the draft guidance. The multidisciplinary audience fostered an environment that was conducive to scientific discussion on a broad range of topics such as clinical impact, immune mitigation strategies, immune prediction and the role of formulation, excipients, aggregates, and degradation products in immunogenicity. This meeting report highlights several key aspects of the 2013 draft guidance together with related dialog from the session.

Enhancing efficiency and quality of statistical estimation of immunogenicity assay cut points through standardization and automation.

PubMed

Su, Cheng; Zhou, Lei; Hu, Zheng; Weng, Winnie; Subramani, Jayanthi; Tadkod, Vineet; Hamilton, Kortney; Bautista, Ami; Wu, Yu; Chirmule, Narendra; Zhong, Zhandong Don

2015-10-01

Biotherapeutics can elicit immune responses, which can alter the exposure, safety, and efficacy of the therapeutics. A well-designed and robust bioanalytical method is critical for the detection and characterization of relevant anti-drug antibody (ADA) and the success of an immunogenicity study. As a fundamental criterion in immunogenicity testing, assay cut points need to be statistically established with a risk-based approach to reduce subjectivity. This manuscript describes the development of a validated, web-based, multi-tier customized assay statistical tool (CAST) for assessing cut points of ADA assays. The tool provides an intuitive web interface that allows users to import experimental data generated from a standardized experimental design, select the assay factors, run the standardized analysis algorithms, and generate tables, figures, and listings (TFL). It allows bioanalytical scientists to perform complex statistical analysis at a click of the button to produce reliable assay parameters in support of immunogenicity studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Approaches to the induction of HIV broadly neutralizing antibodies.

PubMed

Moore, Penny L; Williamson, Carolyn

2016-11-01

A vaccine that elicits antibody responses that can neutralize the diversity of HIV clades has not yet been achieved, and is a major focus of HIV vaccine research. Here, we provide an update on the barriers to eliciting such antibodies, and how advances in immunogen design may circumvent these roadblocks, focusing on data published in the last year. Studies of how broadly neutralizing antibodies (bNAbs) develop in HIV-infected donors continue to produce key insights, suggesting that for some viral targets there are common pathways to developing breadth. Germline-targeting strategies, that aim to recruit rare precursors of bNAbs, have shown promise in immunogenicity studies, and structural biology has led to advances in immunogen design. Mapping of strain-specific tier 2 vaccine responses has highlighted the challenges that remain in driving antibodies toward breadth. Elucidation of the HIV envelope structure, together with an understanding of how bNAbs emerge in vivo has guided the design of new immunogens and vaccine strategies that show promise for eliciting protective antibodies.

Homology analysis and cross-immunogenicity of OmpA from pathogenic Yersinia enterocolitica, Yersinia pseudotuberculosis and Yersinia pestis.

PubMed

Chen, Yuhuang; Duan, Ran; Li, Xu; Li, Kewei; Liang, Junrong; Liu, Chang; Qiu, Haiyan; Xiao, Yuchun; Jing, Huaiqi; Wang, Xin

2015-12-01

The outer membrane protein A (OmpA) is one of the intra-species conserved proteins with immunogenicity widely found in the family of Enterobacteriaceae. Here we first confirmed OmpA is conserved in the three pathogenic Yersinia: Yersinia pestis, Yersinia pseudotuberculosis and pathogenic Yersinia enterocolitica, with high homology at the nucleotide level and at the amino acid sequence level. The identity of ompA sequences for 262 Y. pestis strains, 134 Y. pseudotuberculosis strains and 219 pathogenic Y. enterocolitica strains are 100%, 98.8% and 97.7% similar. The main pattern of OmpA of pathogenic Yersinia are 86.2% and 88.8% identical at the nucleotide and amino acid sequence levels, respectively. Immunological analysis showed the immunogenicity of each OmpA and cross-immunogenicity of OmpA for pathogenic Yersinia where OmpA may be a vaccine candidate for Y. pestis and other pathogenic Yersinia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structure-Based Design of Hepatitis C Virus Vaccines That Elicit Neutralizing Antibody Responses to a Conserved Epitope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, Brian G.; Boucher, Elisabeth N.; Piepenbrink, Kurt H.

Despite recent advances in therapeutic options, hepatitis C virus (HCV) remains a severe global disease burden, and a vaccine can substantially reduce its incidence. Due to its extremely high sequence variability, HCV can readily escape the immune response; thus, an effective vaccine must target conserved, functionally important epitopes. Using the structure of a broadly neutralizing antibody in complex with a conserved linear epitope from the HCV E2 envelope glycoprotein (residues 412 to 423; epitope I), we performed structure-based design of immunogens to induce antibody responses to this epitope. This resulted in epitope-based immunogens based on a cyclic defensin protein, asmore » well as a bivalent immunogen with two copies of the epitope on the E2 surface. We solved the X-ray structure of a cyclic immunogen in complex with the HCV1 antibody and confirmed preservation of the epitope conformation and the HCV1 interface. Mice vaccinated with our designed immunogens produced robust antibody responses to epitope I, and their serum could neutralize HCV. Notably, the cyclic designs induced greater epitope-specific responses and neutralization than the native peptide epitope. Beyond successfully designing several novel HCV immunogens, this study demonstrates the principle that neutralizing anti-HCV antibodies can be induced by epitope-based, engineered vaccines and provides the basis for further efforts in structure-based design of HCV vaccines. IMPORTANCEHepatitis C virus is a leading cause of liver disease and liver cancer, with approximately 3% of the world's population infected. To combat this virus, an effective vaccine would have distinct advantages over current therapeutic options, yet experimental vaccines have not been successful to date, due in part to the virus's high sequence variability leading to immune escape. In this study, we rationally designed several vaccine immunogens based on the structure of a conserved epitope that is the target of broadly neutralizing antibodies.In vivoresults in mice indicated that these antigens elicited epitope-specific neutralizing antibodies, with various degrees of potency and breadth. These promising results suggest that a rational design approach can be used to generate an effective vaccine for this virus.« less

Enhancing the Thermostability and Immunogenicity of a Respiratory Syncytial Virus (RSV) Live-Attenuated Vaccine by Incorporating Unique RSV Line19F Protein Residues.

PubMed

Rostad, Christina A; Stobart, Christopher C; Todd, Sean O; Molina, Samuel A; Lee, Sujin; Blanco, Jorge C G; Moore, Martin L

2018-03-15

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, and an effective vaccine is not yet available. We previously generated an RSV live-attenuated vaccine (LAV) candidate, DB1, which was attenuated by a low-fusion subgroup B F protein (BAF) and codon-deoptimized nonstructural protein genes. DB1 was immunogenic and protective in cotton rats but lacked thermostability and stability of the prefusion conformation of F compared to strains with the line19F gene. We hypothesized that substitution of unique residues from the thermostable A2-line19F strain could thermostabilize DB1 and boost its immunogenicity. We therefore substituted 4 unique line19F residues into the BAF protein of DB1 by site-directed mutagenesis and rescued the recombinant virus, DB1-QUAD. Compared to DB1, DB1-QUAD had improved thermostability at 4°C and higher levels of prefusion F as measured by enzyme-linked immunosorbent assays (ELISAs). DB1-QUAD was attenuated in normal human bronchial epithelial cells, in BALB/c mice, and in cotton rats but grew to wild-type titers in Vero cells. In mice, DB1-QUAD was highly immunogenic and generated significantly higher neutralizing antibody titers to a panel of RSV A and B strains than did DB1. DB1-QUAD was also efficacious against wild-type RSV challenge in mice and cotton rats. Thus, substitution of unique line19F residues into RSV LAV DB1 enhanced vaccine thermostability, incorporation of prefusion F, and immunogenicity and generated a promising vaccine candidate that merits further investigation. IMPORTANCE We boosted the thermostability and immunogenicity of an RSV live-attenuated vaccine candidate by substituting 4 unique residues from the RSV line19F protein into the F protein of the heterologous vaccine strain DB1. The resultant vaccine candidate, DB1-QUAD, was thermostable, attenuated in vivo , highly immunogenic, and protective against RSV challenge in mice and cotton rats. Copyright © 2018 American Society for Microbiology.

FDA advisory committees meet January 26 on Salk HIV-1 immunogen.

PubMed

1995-01-06

Two advisory committees of the Food and Drug Administration (FDA) will meet to consider future trials of the HIV-1 immunogen developed by Dr. Jonas Salk. The Immune Response Corporation has already conducted several studies of the immunogen, and has found improvement in various immunological and other blood tests, and no adverse effects. However, the studies have not been large enough to show conclusively that the treatment has clinical benefit in delaying disease progression. The new, larger trials are intended to demonstrate a delay in disease progression and validate the use of blood-test markers of disease progression for studying an immune-based treatment.

Feedback from the European Bioanalysis Forum: focus workshop on current analysis of immunogenicity: best practices and regulatory hurdles.

PubMed

Goodman, Joanne; Cowen, Simon; Devanarayan, Viswanath; Egging, David; Emrich, Thomas; Golob, Michaela; Kramer, Daniel; McNally, Jim; Munday, James; Nelson, Robert; Pedras-Vasconcelos, João A; Piironen, Timo; Sickert, Denise; Skibeli, Venke; Fjording, Marianne Scheel; Timmerman, Philip

2018-02-01

European Bioanalysis Forum Workshop, Lisbon, Portugal, September 2016: At the recent European Bioanalysis Forum Focus Workshop, 'current analysis of immunogenicity: best practices and regulatory hurdles', several important challenges facing the bioanalytical community in relation to immunogenicity assays were discussed through a mixture of presentations and panel sessions. The main areas of focus were the evolving regulatory landscape, challenges of assay interferences from either drug or target, cut-point setting and whether alternative assays can be used to replace neutralizing antibody assays. This workshop report captures discussions and potential solutions and/or recommendations made by the speakers and delegates.

Cellular GFP Toxicity and Immunogenicity: Potential Confounders in in Vivo Cell Tracking Experiments.

PubMed

Ansari, Amir Mehdi; Ahmed, A Karim; Matsangos, Aerielle E; Lay, Frank; Born, Louis J; Marti, Guy; Harmon, John W; Sun, Zhaoli

2016-10-01

Green Fluorescent protein (GFP), used as a cellular tag, provides researchers with a valuable method of measuring gene expression and cell tracking. However, there is evidence to suggest that the immunogenicity and cytotoxicity of GFP potentially confounds the interpretation of in vivo experimental data. Studies have shown that GFP expression can deteriorate over time as GFP tagged cells are prone to death. Therefore, the cells that were originally marked with GFP do not survive and cannot be accurately traced over time. This review will present current evidence for the immunogenicity and cytotoxicity of GFP in in vivo studies by characterizing these responses.

RNActive® Technology: Generation and Testing of Stable and Immunogenic mRNA Vaccines.

PubMed

Rauch, Susanne; Lutz, Johannes; Kowalczyk, Aleksandra; Schlake, Thomas; Heidenreich, Regina

2017-01-01

Developing effective mRNA vaccines poses certain challenges concerning mRNA stability and ability to induce sufficient immune stimulation and requires a specific panel of techniques for production and testing. Here, we describe the production of stabilized mRNA with enhanced immunogenicity, generated using conventional nucleotides only, by introducing changes to the mRNA sequence and by complexation with the nucleotide-binding peptide protamine (RNActive® technology). Methods described here include the synthesis, purification, and protamine complexation of mRNA vaccines as well as a comprehensive panel of in vitro and in vivo methods for evaluation of vaccine quality and immunogenicity.

Methods and Protocols for Developing Prion Vaccines.

PubMed

Marciniuk, Kristen; Taschuk, Ryan; Napper, Scott

2016-01-01

Prion diseases denote a distinct form of infectivity that is based in the misfolding of a self-protein (PrP(C)) into a pathological, infectious conformation (PrP(Sc)). Efforts to develop vaccines for prion diseases have been complicated by the potential dangers that are associated with induction of immune responses against a self-protein. As a consequence, there is considerable appeal for vaccines that specifically target the misfolded prion conformation. Such conformation-specific immunotherapy is made possible through the identification of vaccine targets (epitopes) that are exclusively presented as a consequence of misfolding. An immune response directed against these targets, termed disease-specific epitopes (DSEs), has the potential to spare the function of the native form of the protein while clearing, or neutralizing, the infectious isomer. Although identification of DSEs represents a critical first step in the induction of conformation-specific immune responses, substantial efforts are required to translate these targets into functional vaccines. Due to the poor immunogenicity that is inherent to self-proteins, and that is often associated with short peptides, substantial efforts are required to overcome tolerance-to-self and maximize the resultant immune response following DSE-based immunization. This often includes optimization of target sequences in terms of immunogenicity and development of effective formulation and delivery strategies for the associated peptides. Further, these vaccines must satisfy additional criteria from perspectives of specificity (PrP(C) vs. PrP(Sc)) and safety (antibody-induced template-driven misfolding of PrP(C)). The emphasis of this report is on the steps required to translate DSEs into prion vaccines and subsequent evaluation of the resulting immune responses.

Comparison of safety and immunogenicity of purified chick embryo cell vaccine using Zagreb and Essen regimens in patients with category II exposure in China.

PubMed

Hu, Quan; Liu, Man-Qing; Zhu, Zheng-Gang; Zhu, Ze-Rong; Lu, Sha

2014-01-01

The aim was to compare the safety and immunogenicity of purified chick embryo cell vaccine (PCECV) with Zagreb 2-1-1 and Essen 1-1-1-1-1 regimens in patients with WHO category II exposure in China. Side effects including systemic and local symptoms were recorded for all patients during vaccination with purified chick embryo cell vaccine (PCECV) under Zagreb 2-1-1 or Essen 1-1-1-1-1 regimens, and the rabies neutralization antibody titers in patients' serum at days 0, 7, 14, 45, 365 post-immunization were measured to determine the immunogenicity. Fever and pain were the most common events for systemic and local symptoms respectively, and most side effects (86.78%, 105/121) occurred after the first dose of vaccination. Safety analysis showed differences in side effects in<5-year-old patients between Zagreb and Essen regimens, especially after the first dose of vaccination (P = 0.043). Immunogenicity analysis indicated that Zagreb can achieve higher neutralization antibody titers and a greater seroconversion rate in a shorter time but had less persistence than Essen. When compared with the Essen regimen, the Zagreb regimen had a different immunogenicity in all study subjects, and different safety profile in young children, and a further study with a larger population and longer surveillance is warranted.

Aggregated Recombinant Human Interferon Beta Induces Antibodies but No Memory in Immune-Tolerant Transgenic Mice

PubMed Central

Sauerborn, Melody; Gilli, Francesca; Brinks, Vera; Schellekens, Huub; Jiskoot, Wim

2010-01-01

ABSTRACT Purpose To study the influence of protein aggregation on the immunogenicity of recombinant human interferon beta (rhIFNβ) in wild-type mice and transgenic, immune-tolerant mice, and to evaluate the induction of immunological memory. Methods RhIFNβ-1b and three rhIFNβ-1a preparations with different aggregate levels were injected intraperitoneally in mice 15× during 3 weeks, and the mice were rechallenged with rhIFNβ-1a. The formation of binding (BABs) and neutralizing antibodies (NABs) was monitored. Results Bulk rhIFNβ-1a contained large, mainly non-covalent aggregates and stressed rhIFNβ-1a mainly covalent, homogeneous (ca. 100 nm) aggregates. Reformulated rhIFNβ-1a was essentially aggregate-free. All products induced BABs and NABs in wild-type mice. Immunogenicity in the transgenic mice was product dependent. RhIFNβ-1b showed the highest and reformulated rhIFNβ-1a the lowest immunogenicity. In contrast with wild-type mice, transgenic mice did not show NABs, nor did they respond to the rechallenge. Conclusions The immunogenicity of the products in transgenic mice, unlike in wild-type mice, varied. In the transgenic mice, neither NABs nor immunological memory developed. The immunogenicity of rhIFNβ in a model reflecting the human immune system depends on the presence and the characteristics of aggregates. PMID:20499141

A novel pathway combining calreticulin exposure and ATP secretion in immunogenic cancer cell death

PubMed Central

Garg, Abhishek D; Krysko, Dmitri V; Verfaillie, Tom; Kaczmarek, Agnieszka; Ferreira, Gabriela B; Marysael, Thierry; Rubio, Noemi; Firczuk, Malgorzata; Mathieu, Chantal; Roebroek, Anton J M; Annaert, Wim; Golab, Jakub; de Witte, Peter; Vandenabeele, Peter; Agostinis, Patrizia

2012-01-01

Surface-exposed calreticulin (ecto-CRT) and secreted ATP are crucial damage-associated molecular patterns (DAMPs) for immunogenic apoptosis. Inducers of immunogenic apoptosis rely on an endoplasmic reticulum (ER)-based (reactive oxygen species (ROS)-regulated) pathway for ecto-CRT induction, but the ATP secretion pathway is unknown. We found that after photodynamic therapy (PDT), which generates ROS-mediated ER stress, dying cancer cells undergo immunogenic apoptosis characterized by phenotypic maturation (CD80high, CD83high, CD86high, MHC-IIhigh) and functional stimulation (NOhigh, IL-10absent, IL-1βhigh) of dendritic cells as well as induction of a protective antitumour immune response. Intriguingly, early after PDT the cancer cells displayed ecto-CRT and secreted ATP before exhibiting biochemical signatures of apoptosis, through overlapping PERK-orchestrated pathways that require a functional secretory pathway and phosphoinositide 3-kinase (PI3K)-mediated plasma membrane/extracellular trafficking. Interestingly, eIF2α phosphorylation and caspase-8 signalling are dispensable for this ecto-CRT exposure. We also identified LRP1/CD91 as the surface docking site for ecto-CRT and found that depletion of PERK, PI3K p110α and LRP1 but not caspase-8 reduced the immunogenicity of the cancer cells. These results unravel a novel PERK-dependent subroutine for the early and simultaneous emission of two critical DAMPs following ROS-mediated ER stress. PMID:22252128

Immunoproteomic identification of immunogenic proteins in Cronobacter sakazakii strain BAA-894.

PubMed

Wang, Jian; Du, Xin-Jun; Lu, Xiao-Nan; Wang, Shuo

2013-03-01

Cronobacter spp. are emerging opportunistic pathogens. Cronobacter sakazakii is considered as the predominant species in all infections. So far, our understanding of the species' immunogens and potential virulence factors of Cronobacter spp. remains limited. In this study, an immunoproteomic approach was used to investigate soluble and insoluble proteins from the genome-sequenced strain C. sakazakii ATCC BAA-894. Proteins were separated using two-dimensional electrophoresis, detected by Western blotting with polyclonal antibodies of C. sakazakii BAA-894, and identified using tandem mass spectrometry (MALDI-MS and MALDI-MS/MS, MS/MSMS). A total of 11 immunoreactive proteins were initially identified in C. sakazakii BAA-894, including two outer membrane proteins, four periplasmic proteins, and five cytoplasmic proteins. In silico functional analysis of the 11 identified proteins indicated three proteins that were initially described as immunogens of pathogenic bacteria. For the remaining eight proteins, one protein was categorized as a potential virulence factor involved in protection against reactive oxygen species, and seven proteins were considered to play potential roles in adhesion, invasion, and biofilm formation. To our knowledge, this is the first time that immunogenic proteins of C. sakazakii BAA-894 have been identified as immunogens and potential virulence factors by an immunoproteomics approach. Future studies should investigate the roles of these proteins in bacterial pathogenesis and modulation of host immune responses during infection to identify their potential as molecular therapeutic targets.

Investigation of the immunogenicity of different types of aggregates of a murine monoclonal antibody in mice.

PubMed

Freitag, Angelika J; Shomali, Maliheh; Michalakis, Stylianos; Biel, Martin; Siedler, Michael; Kaymakcalan, Zehra; Carpenter, John F; Randolph, Theodore W; Winter, Gerhard; Engert, Julia

2015-02-01

The potential contribution of protein aggregates to the unwanted immunogenicity of protein pharmaceuticals is a major concern. In the present study a murine monoclonal antibody was utilized to study the immunogenicity of different types of aggregates in mice. Samples containing defined types of aggregates were prepared by processes such as stirring, agitation, exposure to ultraviolet (UV) light and exposure to elevated temperatures. Aggregates were analyzed by size-exclusion chromatography, light obscuration, turbidimetry, infrared (IR) spectroscopy and UV spectroscopy. Samples were separated into fractions based on aggregate size by asymmetrical flow field-flow fractionation or by centrifugation. Samples containing different types and sizes of aggregates were subsequently administered to C57BL/6 J and BALB/c mice, and serum was analyzed for the presence of anti-IgG1, anti-IgG2a, anti-IgG2b and anti-IgG3 antibodies. In addition, the pharmacokinetic profile of the murine antibody was investigated. In this study, samples containing high numbers of different types of aggregates were administered in order to challenge the in vivo system. The magnitude of immune response depends on the nature of the aggregates. The most immunogenic aggregates were of relatively large and insoluble nature, with perturbed, non-native structures. This study shows that not all protein drug aggregates are equally immunogenic.

AAV-expressed eCD4-Ig provides durable protection from multiple SHIV challenges

PubMed Central

Gardner, Matthew R.; Kattenhorn, Lisa M.; Kondur, Hema R.; von Schaewen, Markus; Dorfman, Tatyana; Chiang, Jessica J.; Haworth, Kevin G.; Decker, Julie M.; Alpert, Michael D.; Bailey, Charles C.; Neale, Ernest S.; Fellinger, Christoph H.; Joshi, Vinita R.; Fuchs, Sebastian P.; Martinez-Navio, Jose M.; Quinlan, Brian D.; Yao, Annie Y.; Mouquet, Hugo; Gorman, Jason; Zhang, Baoshan; Poignard, Pascal; Nussenzweig, Michel C.; Burton, Dennis R.; Kwong, Peter D.; Piatak, Michael; Lifson, Jeffrey D.; Gao, Guangping; Desrosiers, Ronald C.; Evans, David T.; Hahn, Beatrice H.; Ploss, Alexander; Cannon, Paula M.; Seaman, Michael S.; Farzan, Michael

2015-01-01

Long-term in vivo expression of a broad and potent entry inhibitor could circumvent the need for a conventional vaccine for HIV-1. Adeno-associated virus (AAV) vectors can stably express HIV-1 broadly neutralizing antibodies (bNAbs)1,2. However even the best bNAbs neutralize 10–50% of HIV-1 isolates inefficiently (IC80 > 5 μg/ml), suggesting that high concentrations of these antibodies would be necessary to achieve general protection3–6. Here we show that eCD4-Ig, a fusion of CD4-Ig with a small CCR5-mimetic sulfopeptide, binds avidly and cooperatively to the HIV-1 envelope glycoprotein (Env) and is more potent than the best bNAbs (geometric mean IC50 < 0.05 μg/ml). Because eCD4-Ig binds only conserved regions of Env, it is also much broader than any bNAb. For example, eCD4-Ig efficiently neutralized 100% of a diverse panel of neutralization-resistant HIV-1, HIV-2, and SIV isolates, including a comprehensive set of isolates resistant to the CD4-binding site bNAbs VRC01, NIH45-46, and 3BNC117. Rhesus macaques inoculated with an AAV vector stably expressed 17 to 77 μg/ml of fully functional rhesus eCD4-Ig for 40 weeks, and these macaques were protected from multiple infectious challenges with SHIV-AD8. Rhesus eCD4-Ig was also markedly less immunogenic than rhesus forms of four well characterized bNAbs. Our data suggest that AAV-delivered eCD4-Ig can function like an effective HIV-1 vaccine. PMID:25707797

Use of parvovirus-like particles for vaccination and induction of multiple immune responses.

PubMed

Casal, J I

1999-04-01

Expression of the VP2 gene of autonomous parvoviruses in insect cells with the use of the baculovirus system has led to the production of virus-like particles (VLPs) formed by the self-assembly of VP2. These VLPs are expressed at high levels and can easily be purified by salt fractionation. They are highly immunogenic in the corresponding host, being fully protective at doses as low as 1-2 microg of purified material per animal. No special adjuvants are required. An interesting property of these particles is their usefulness as a diagnostic reagent for ELISA kits, which have successfully replaced conventional methods for parvovirus diagnostics based on haemagglutination. Another application of the hybrid recombinant parvovirus-like particles of pig parvovirus (PPV) and canine parvovirus (CPV) is its use as an antigen delivery system. PPV:VLPs containing a CD8(+) epitope from the lymphocytic choriomeningitis virus (LCMV) nucleoprotein are able to evoke a potent cytolytic T-lymphocyte response and to protect mice against a lethal infection with LCMV. Also, PPV:VLPs containing the C3:T epitope from poliovirus elicited a T helper response in mice. These T-cell epitopes were inserted into the N-terminus of the VP2 protein. Unfortunately, the N-terminus is not adequate for antibody responses because it is inside the particle. Recent findings have shown that fine tailoring of the point of insertion around the tip of loop 2 of the surface of CPV allowed the elicitation of a potent antibody response. Thus mice immunized with chimaeric C3:B CPV:VLPs were able to elicit a strong neutralizing antibody response (>3 log10 units) against poliovirus. We now have the possibility of using these particles to elicit different immune responses against single or multiple pathogens in a simple and economic way.

Developing novel immunogens for a safe and effective Alzheimer's disease vaccine.

PubMed

Lemere, Cynthia A

2009-01-01

Alzheimer's disease (AD) is the most prevalent form of neurodegeneration; however, therapies to prevent or treat AD are inadequate. Amyloid-beta (Abeta) protein accrues in cortical senile plaques, one of the key neuropathological hallmarks of AD, and is elevated in brains of early onset AD patients in a small number of families that bear certain genetic mutations, further implicating its role in this devastating neurological disease. In addition, soluble Abeta oligomers have been shown to be detrimental to neuronal function. Therapeutic strategies aimed at lowering cerebral Abeta levels are currently under development. One strategy is to immunize AD patients with Abeta peptides so that they will generate antibodies that bind to Abeta protein and enhance its clearance. As of 1999, Abeta immunotherapy, either through active immunization with Abeta peptides or through passive transfer of Abeta-specific antibodies, has been shown to reduce cerebral Abeta levels and improve cognitive deficits in AD mouse models and lower plaque load in nonhuman primates. However, a Phase II clinical trial of active immunization using full-length human Abeta1-42 peptide and a strong Th1-biased adjuvant, QS-21, ended prematurely in 2002 because of the onset of meningoencephalitis in approximately 6% of the AD patients enrolled in the study. It is possible that T cell recognition of the human full-length Abeta peptide as a self-protein may have induced an adverse autoimmune response in these patients. Although only approximately 20% of immunized patients generated anti-Abeta titers, responders showed some general slowing of cognitive decline. Focal cortical regions devoid of Abeta plaques were observed in brain tissues of several immunized patients who have since come to autopsy. In order to avoid a deleterious immune response, passive Abeta immunotherapy is under investigation by administering monthly intravenous injections of humanized Abeta monoclonal antibodies to AD patients. However, a safe and effective active Abeta vaccine would be more cost-effective and more readily available to a larger AD population. We have developed several novel short Abeta immunogens that target the Abeta N-terminus containing a strong B cell epitope while avoiding the Abeta mid-region and C-terminus containing T cell epitopes. These immunogens include dendrimeric Abeta1-15 (16 copies of Abeta1-15 on a lysine antigen tree), 2xAbeta1-15 (a tandem repeat of two lysine-linked Abeta1-15 peptides), and 2xAbeta1-15 with the addition of a three amino acid RGD motif (R-2xAbeta1-15). Intranasal immunization with our short Abeta fragment immunogens and a mucosal adjuvant, mutant Escherichia coli heat-labile enterotoxin LT(R192G), resulted in reduced cerebral Abeta levels, plaque deposition, and gliosis, as well as increased plasma Abeta levels and improved cognition in a transgenic mouse model of AD. Preclinical trials in nonhuman primates, and human clinical trials using similar Abeta immunogens, are now underway. Abeta immunotherapy looks promising but must be made safer and more effective at generating antibody titers in the elderly. It is hoped that these novel immunogens will enhance Abeta antibody generation across a broad population and avoid the adverse events seen in the earlier clinical trial.

Calreticulin exposure by malignant blasts correlates with robust anticancer immunity and improved clinical outcome in AML patients

PubMed Central

Fucikova, Jitka; Truxova, Iva; Hensler, Michal; Becht, Etienne; Kasikova, Lenka; Moserova, Irena; Vosahlikova, Sarka; Klouckova, Jana; Church, Sarah E.; Cremer, Isabelle; Kepp, Oliver; Kroemer, Guido; Galluzzi, Lorenzo; Salek, Cyril

2016-01-01

Cancer cell death can be perceived as immunogenic by the host only when malignant cells emit immunostimulatory signals (so-called “damage-associated molecular patterns,” DAMPs), as they die in the context of failing adaptive responses to stress. Accumulating preclinical and clinical evidence indicates that the capacity of immunogenic cell death to (re-)activate an anticancer immune response is key to the success of various chemo- and radiotherapeutic regimens. Malignant blasts from patients with acute myeloid leukemia (AML) exposed multiple DAMPs, including calreticulin (CRT), heat-shock protein 70 (HSP70), and HSP90 on their plasma membrane irrespective of treatment. In these patients, high levels of surface-exposed CRT correlated with an increased proportion of natural killer cells and effector memory CD4+ and CD8+ T cells in the periphery. Moreover, CRT exposure on the plasma membrane of malignant blasts positively correlated with the frequency of circulating T cells specific for leukemia-associated antigens, indicating that ecto-CRT favors the initiation of anticancer immunity in patients with AML. Finally, although the levels of ecto-HSP70, ecto-HSP90, and ecto-CRT were all associated with improved relapse-free survival, only CRT exposure significantly correlated with superior overall survival. Thus, CRT exposure represents a novel powerful prognostic biomarker for patients with AML, reflecting the activation of a clinically relevant AML-specific immune response. PMID:27802968

Safety and Immunogenicity of ChAd63 and MVA ME-TRAP in West African Children and Infants

PubMed Central

Afolabi, Muhammed O; Tiono, Alfred B; Adetifa, Uche J; Yaro, Jean Baptiste; Drammeh, Abdoulie; Nébié, Issa; Bliss, Carly; Hodgson, Susanne H; Anagnostou, Nicholas A; Sanou, Guillaume S; Jagne, Ya Jankey; Ouedraogo, Oumarou; Tamara, Casimir; Ouedraogo, Nicolas; Ouedraogo, Mirielle; Njie-Jobe, Jainaba; Diarra, Amidou; Duncan, Christopher JA; Cortese, Riccardo; Nicosia, Alfredo; Roberts, Rachel; Viebig, Nicola K; Leroy, Odile; Lawrie, Alison M; Flanagan, Katie L; Kampman, Beate; Bejon, Philip; Imoukhuede, Egeruan B; Ewer, Katie J; Hill, Adrian VS; Bojang, Kalifa; Sirima, Sodiomon B

2016-01-01

Malaria remains a significant global health burden and a vaccine would make a substantial contribution to malaria control. Chimpanzee Adenovirus 63 Modified Vaccinia Ankara Multiple epitope thrombospondin adhesion protein (ME-TRAP) and vaccination has shown significant efficacy against malaria sporozoite challenge in malaria-naive European volunteers and against malaria infection in Kenyan adults. Infants are the target age group for malaria vaccination; however, no studies have yet assessed T-cell responses in children and infants. We enrolled 138 Gambian and Burkinabe children in four different age-groups: 2–6 years old in The Gambia; 5–17 months old in Burkina Faso; 5–12 months old, and also 10 weeks old, in The Gambia; and evaluated the safety and immunogenicity of Chimpanzee Adenovirus 63 Modified Vaccinia Ankara ME-TRAP heterologous prime-boost immunization. The vaccines were well tolerated in all age groups with no vaccine-related serious adverse events. T-cell responses to vaccination peaked 7 days after boosting with Modified Vaccinia Ankara, with T-cell responses highest in 10 week-old infants. Heterologous prime-boost immunization with Chimpanzee Adenovirus 63 and Modified Vaccinia Ankara ME-TRAP was well tolerated in infants and children, inducing strong T-cell responses. We identify an approach that induces potent T-cell responses in infants, which may be useful for preventing other infectious diseases requiring cellular immunity. PMID:27109630

The delicate balance in genetically engineering live vaccines

PubMed Central

Galen, James E.; Curtiss, Roy

2014-01-01

Contemporary vaccine development relies less on empirical methods of vaccine construction, and now employs a powerful array of precise engineering strategies to construct immunogenic live vaccines. In this review, we will survey various engineering techniques used to create attenuated vaccines, with an emphasis on recent advances and insights. We will further explore the adaptation of attenuated strains to create multivalent vaccine platforms for immunization against multiple unrelated pathogens. These carrier vaccines are engineered to deliver sufficient levels of protective antigens to appropriate lymphoid inductive sites to elicit both carrier-specific and foreign antigen-specific immunity. Although many of these technologies were originally developed for use in Salmonella vaccines, application of the essential logic of these approaches will be extended to development of other enteric vaccines where possible. A central theme driving our discussion will stress that the ultimate success of an engineered vaccine rests on achieving the proper balance between attenuation and immunogenicity. Achieving this balance will avoid over-activation of inflammatory responses, which results in unacceptable reactogenicity, but will retain sufficient metabolic fitness to enable the live vaccine to reach deep tissue inductive sites and trigger protective immunity. The breadth of examples presented herein will clearly demonstrate that genetic engineering offers the potential for rapidly propelling vaccine development forward into novel applications and therapies which will significantly expand the role of vaccines in public health. PMID:24370705

76 FR 60510 - Prospective Grant of Exclusive License: Compositions and Method for Preventing Reactogenicity...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-29

... Immunogenic Live Rotavirus Compositions AGENCY: National Institutes of Health, Public Health Service, HHS... Associated with Administration of Immunogenic Live Rotavirus Compositions,'' and all continuing applications... license territory may be ``worldwide'', and the field of use may be limited to ``rhesus-based rotavirus...

A STUDY OF IMMUNOGENIC AND ANTIGENIC PROPERTIES OF DIPHTHERIA TOXOID EXPOSED TO STERILIZING DOSES OF $gamma$-RAYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaulen, D.R.

1959-01-01

Experimental results indicate that crude diphtheria toxoid may be exposed to sterilizing doses of gamma radiation without damage of its properties. Exposure of purified and adsorbed preparations resulted in a deterioration of immunogenic and antigenic properties of diphtheria toxoid. (C.H.)

Effects of glycosylation on antigenicity and immunogenicity of classical swine fever virus envelope proteins

USDA-ARS?s Scientific Manuscript database

Classical swine fever virus (CSFV) harbors three envelope glycoproteins (E(rns), E1 and E2). Previous studies have demonstrated that removal of specific glycosylation sites within these proteins yielded attenuated and immunogenic CSFV mutants. Here we analyzed the effects of lack of glycosylation of...

Antigenic Structure of the Human Muscle Nicotinic Acetylcholine Receptor Main Immunogenic Region

PubMed Central

Luo, Jie; Lindstrom, Jon

2009-01-01

The main immunogenic region on the α1 subunits of muscle nicotinic acetylcholine receptors provokes half or more of the autoantibodies in myasthenia gravis and its animal model. Many of these autoantibodies depend on the native conformation of the receptor for their ability to bind with high affinity. We mapped this region and explained the conformation-dependence of its epitopes by making chimeras in which sequences of human muscle α1 subunits were replaced in human neuronal α7 subunits or Aplysia acetylcholine binding protein. These chimeras also revealed that the main immunogenic region can play a major role in promoting conformational maturation, and, consequently, assembly of receptor subunits. PMID:19705087

Idiotypic specificities and cross-reactivities of rabbit antibodies to human antidextran.

PubMed

Outschoorn, I M

1979-10-01

Idiotypic antibodies were prepared by immunizing two groups of rabbits with dextran-antidextran specific precipitates and purified antidextran obtained subsequently from the same human donor. Half of the animals were made tolerant to pooled human IgG. Tests showed that sera from tolerant rabbits reacted better with the antidextran preparation used to immunize the other group of animals than with the antidextran that formed part of their immunogen. Non-tolerant animals did not recognize this serological difference. Sera from animals immunized with the antidextran preparation donated later reacted better with this material irrespective of their tolerance to human IgG.

Randomized trial on the safety, tolerability, and immunogenicity of MenACWY-CRM, an investigational quadrivalent meningococcal glycoconjugate vaccine, administered concomitantly with a combined tetanus, reduced diphtheria, and acellular pertussis vaccine in adolescents and young adults.

PubMed

Gasparini, Roberto; Conversano, Michele; Bona, Gianni; Gabutti, Giovanni; Anemona, Alessandra; Dull, Peter M; Ceddia, Francesca

2010-04-01

This study evaluated the safety, tolerability, and immunogenicity of an investigational quadrivalent meningococcal conjugate vaccine, MenACWY-CRM, when administered concomitantly with a combined tetanus, reduced diphtheria, and acellular pertussis (Tdap) vaccine, in subjects aged 11 to 25 years. Subjects received either MenACWY-CRM and Tdap, MenACWY-CRM and saline placebo, or Tdap and saline placebo. No significant increase in reactogenicity and no clinically significant vaccine-related adverse events (AEs) occurred when MenACWY-CRM and Tdap were administered concomitantly. Similar immunogenic responses to diphtheria, tetanus, and meningococcal (serogroups A, C, W-135, and Y) antigens were observed, regardless of concomitant vaccine administration. Antipertussis antibody responses were comparable between vaccine groups for filamentous hemagglutinin and were slightly lower, although not clinically significantly, for pertussis toxoid and pertactin when the two vaccines were administered concomitantly. These results indicate that the investigational MenACWY-CRM vaccine is well tolerated and immunogenic and that it can be coadministered with Tdap to adolescents and young adults.

Immune interaction between components of acellular pertussis-diphtheria-tetanus (DTaP) vaccine and Haemophilus influenzae b (Hib) conjugate vaccine in a rat model.

PubMed

Mawas, Fatme; Dickinson, Robert; Douglas-Bardsley, Alexandra; Xing, Dorothy K L; Sesardic, Dorothea; Corbel, Michael J

2006-04-24

We have previously shown that, consistent with clinical trial results, the immune response to a Haemophilus influenzae b (Hib) conjugate vaccine in a rat model was compromised and modulated when given combined with a DTaP3 vaccine, as compared to both vaccines given separately. The present study extended our investigation to evaluate the immunogenicity of all DTaP3 components in combined versus separate administration of Hib with DTaP3 and investigated immune interactions between Hib and individual components of DTaP3. Rats were immunised with Hib and DTaP3 or with Hib and individual DTaP3 components. Cellular and humoral immune responses to Hib and DTaP3 components were evaluated. Our results indicate that the immunogenicity of DTaP3 components was similar or greater in combined versus separate administration of Hib and DTaP3. Moreover, combined administration of Hib and TT reduced immunogenicity of both Hib and TT. Hib immunogenicity was also significantly reduced when given combined with FHA and following adsorption to Al(OH)3.

Oligopeptide M13 Phage Display in Pathogen Research

PubMed Central

Kügler, Jonas; Zantow, Jonas; Meyer, Torsten; Hust, Michael

2013-01-01

Phage display has become an established, widely used method for selection of peptides, antibodies or alternative scaffolds. The use of phage display for the selection of antigens from genomic or cDNA libraries of pathogens which is an alternative to the classical way of identifying immunogenic proteins is not well-known. In recent years several new applications for oligopeptide phage display in disease related fields have been developed which has led to the identification of various new antigens. These novel identified immunogenic proteins provide new insights into host pathogen interactions and can be used for the development of new diagnostic tests and vaccines. In this review we focus on the M13 oligopeptide phage display system for pathogen research but will also give examples for lambda phage display and for applications in other disease related fields. In addition, a detailed technical work flow for the identification of immunogenic oligopeptides using the pHORF system is given. The described identification of immunogenic proteins of pathogens using oligopeptide phage display can be linked to antibody phage display resulting in a vaccine pipeline. PMID:24136040

Oligopeptide m13 phage display in pathogen research.

PubMed

Kügler, Jonas; Zantow, Jonas; Meyer, Torsten; Hust, Michael

2013-10-16

Phage display has become an established, widely used method for selection of peptides, antibodies or alternative scaffolds. The use of phage display for the selection of antigens from genomic or cDNA libraries of pathogens which is an alternative to the classical way of identifying immunogenic proteins is not well-known. In recent years several new applications for oligopeptide phage display in disease related fields have been developed which has led to the identification of various new antigens. These novel identified immunogenic proteins provide new insights into host pathogen interactions and can be used for the development of new diagnostic tests and vaccines. In this review we focus on the M13 oligopeptide phage display system for pathogen research but will also give examples for lambda phage display and for applications in other disease related fields. In addition, a detailed technical work flow for the identification of immunogenic oligopeptides using the pHORF system is given. The described identification of immunogenic proteins of pathogens using oligopeptide phage display can be linked to antibody phage display resulting in a vaccine pipeline.

Combined immunogenicity data for a new DTaP-IPV-Hep B-PRP-T vaccine (Hexaxim) following primary series administration at 2, 4, 6 months of age in Latin America.

PubMed

Santos-Lima, Eduardo; B'Chir, Siham; Lane, Andrew

2013-02-18

The immunogenicity of a primary series of a new, fully liquid DTaP-IPV-Hep B-PRP-T vaccine (Hexaxim), administered at 2, 4, 6 months of age in four clinical studies is reviewed. Immunogenicity data at 1 month after the third vaccination were assessed and pooled from a total of 1270 participants (per-protocol population) in four randomized clinical trials in Argentina, Mexico, and Peru. Hepatitis B vaccine was not administered at birth. All seroprotection (D, T, polio-1, -2, -3, Hep B, PRP-T [Hib]), seroconversion (PT and FHA), and vaccine response (PT and FHA) data were high, and were similar to licensed comparators (pooled SP, SC, and VR rates were 97.1-100%, 96.0-97.0%, and 99.7-99.9%, respectively). These data show the good immunogenicity of this new hexavalent vaccine that can provide the opportunity to increase global compliance to complex pediatric vaccination schedules. Copyright © 2013. Published by Elsevier Ltd.

Design of a platform technology for systemic delivery of siRNA to tumours using rolling circle transcription

NASA Astrophysics Data System (ADS)

Jang, Mihue; Kim, Jong Hwan; Nam, Hae Yun; Kwon, Ick Chan; Ahn, Hyung Jun

2015-08-01

For therapeutic applications of siRNA, there are technical challenges with respect to targeted and systemic delivery. We here report a new siRNA carrier, RNAtr NPs, in a way that multiple tandem copies of RNA hairpins as a result of rolling circle transcription (RCT) can be readily adapted in tumour-targeted and systemic siRNA delivery. RNAtr NPs provide a means of condensing large amounts of multimeric RNA transcripts into the compact nanoparticles, especially without the aid of polycationic agents, and thus reduce the risk of immunogenicity and cytotoxicity by avoiding the use of synthetic polycationic reagents. This strategy allows the design of a platform technology for systemic delivery of siRNA to tumour sites, because RCT reaction, which enzymatically generates RNA polymers in multiple copy numbers at low cost, can lead to directly accessible routes to targeted and systemic delivery. Therefore, RNAtr NPs suggest great potentials as the siRNA therapeutics for cancer treatment.

DEVELOPING A VACCINE AGAINST MULTIPLE PSYCHOACTIVE TARGETS: A CASE STUDY OF HEROIN

PubMed Central

Stowe, G. Neil; Schlosburg, Joel E.; Vendruscolo, Leandro F.; Edwards, Scott; Misra, Kaushik K.; Schulteis, Gery; Zakhari, Joseph S.; Koob, George F.; Janda, Kim D.

2012-01-01

Heroin addiction is a wide-reaching problem with a spectrum of damaging social consequences. Currently approved heroin addiction medications include drugs that bind at the same receptors (e.g. opioid receptors) occupied by heroin and/or its metabolites in the brain, but undesired side effects of these treatments, maintenance dependence and relapse to drug taking remains problematic. A vaccine capable of blocking heroin’s effects could provide an economical, long-lasting and sustainable adjunct to heroin addiction therapy without the side effects associated with available treatment options. Heroin, however, presents a particularly challenging vaccine target as it is metabolized to multiple psychoactive molecules of differing lipophilicity, with differing abilities to cross the blood brain barrier. In this review, we discuss the opiate scaffolding and hapten design considerations to confer immunogenicity as well as the specificity of the immune response towards structurally similar opiates. In addition, we detail different strategies employed in the design of immunoconjugates for a vaccine-based therapy for heroin addiction treatment. PMID:22229311

Improved immunogenicity of individual influenza vaccine components delivered with a novel dissolving microneedle patch stable at room temperature

PubMed Central

Vassilieva, Elena V.; Kalluri, Haripriya; McAllister, Devin; Taherbhai, Misha T.; Esser, E. Stein; Pewin, Winston P.; Pulit-Penaloza, Joanna A.; Prausnitz, Mark R.; Compans, Richard W.; Skountzou, Ioanna

2015-01-01

Prevention of seasonal influenza epidemics and pandemics relies on widespread vaccination coverage to induce protective immunity. In addition to a good antigenic match with the circulating viruses, the effectiveness of individual strains represented in the trivalent vaccines depends on their immunogenicity. In this study we evaluated the immunogenicity of H1N1, H3N2 and B seasonal influenza virus vaccine strains delivered individually with a novel dissolving microneedle patch and the stability of this formulation during storage at 25°C. Our data demonstrate that all strains retained their antigenic activity after incorporation in the dissolving patches as measured by SRID assay and immune responses to vaccination in BALB/c mice. After a single immunization all three antigens delivered with microneedle patches induced superior neutralizing antibody titers compared to intramuscular immunization. Cutaneous antigen delivery was especially beneficial for the less immunogenic B strain. Mice immunized with dissolving microneedle patches encapsulating influenza A/Brisbane/59/07 (H1N1) vaccine were fully protected against lethal challenge by homologous mouse-adapted influenza virus. All vaccine components retained activity during storage at room temperature for at least three months as measured in vitro by SRID assay and in vivo by mouse immunization studies. Our data demonstrate that dissolving microneedle patches are a promising advance for influenza cutaneous vaccination due to improved immune responses using less immunogenic influenza antigens and enhanced stability. PMID:25895053

Approaches to Mitigate the Unwanted Immunogenicity of Therapeutic Proteins during Drug Development.

PubMed

Salazar-Fontana, Laura I; Desai, Dharmesh D; Khan, Tarik A; Pillutla, Renuka C; Prior, Sandra; Ramakrishnan, Radha; Schneider, Jennifer; Joseph, Alexandra

2017-03-01

All biotherapeutics have the potential to induce an immune response. This immunological response is complex and, in addition to antibody formation, involves T cell activation and innate immune responses that could contribute to adverse effects. Integrated immunogenicity data analysis is crucial to understanding the possible clinical consequences of anti-drug antibody (ADA) responses. Because patient- and product-related factors can influence the immunogenicity of a therapeutic protein, a risk-based approach is recommended and followed by most drug developers to provide insight over the potential harm of unwanted ADA responses. This paper examines mitigation strategies currently implemented and novel under investigation approaches used by drug developers. The review describes immunomodulatory regimens used in the clinic to mitigate deleterious ADA responses to replacement therapies for deficiency syndromes, such as hemophilia A and B, and high risk classical infantile Pompe patients (e.g., cyclophosphamide, methotrexate, rituximab); novel in silico and in vitro prediction tools used to select candidates based on their immunogenicity potential (e.g., anti-CD52 antibody primary sequence and IFN beta-1a formulation); in vitro generation of tolerogenic antigen-presenting cells (APCs) to reduce ADA responses to factor VIII and IX in murine models of hemophilia; and selection of novel delivery systems to reduce in vivo ADA responses to highly immunogenic biotherapeutics (e.g., asparaginase). We conclude that mitigation strategies should be considered early in development for biotherapeutics based on our knowledge of existing clinical data for biotherapeutics and the immune response involved in the generation of these ADAs.

Oxygen-boosted immunogenic photodynamic therapy with gold nanocages@manganese dioxide to inhibit tumor growth and metastases.

PubMed

Liang, Ruijing; Liu, Lanlan; He, Huamei; Chen, Zhikuan; Han, Zhiqun; Luo, Zhenyu; Wu, Zhihao; Zheng, Mingbin; Ma, Yifan; Cai, Lintao

2018-09-01

Metastatic triple-negative breast cancer (mTNBC) is an aggressive disease among women worldwide, characterized by high mortality and poor prognosis despite systemic therapy with radiation and chemotherapies. Photodynamic therapy (PDT) is an important strategy to eliminate the primary tumor, however its therapeutic efficacy against metastases and recurrence is still limited. Here, we employed a template method to develop the core-shell gold nanocage@manganese dioxide (AuNC@MnO 2 , AM) nanoparticles as tumor microenvironment responsive oxygen producers and near-infrared (NIR)-triggered reactive oxygen species (ROS) generators for oxygen-boosted immunogenic PDT against mTNBC. In this platform, MnO 2 shell degrades in acidic tumor microenvironment pH/H 2 O 2 conditions and generates massive oxygen to boost PDT effect of AM nanoparticles under laser irradiation. Fluorescence (FL)/photoacoustic (PA)/magnetic resonance (MR) multimodal imaging confirms the effective accumulation of AM nanoparticles with sufficient oxygenation in tumor site to ameliorate local hypoxia. Moreover, the oxygen-boosted PDT effect of AM not only destroys primary tumor effectively but also elicits immunogenic cell death (ICD) with damage-associated molecular patterns (DAMPs) release, which subsequently induces DC maturation and effector cells activation, thereby robustly evoking systematic antitumor immune responses against mTNBC. Hence, this oxygen-boosted immunogenic PDT nanosystem offers a promising approach to ablate primary tumor and simultaneously prevent tumor metastases via immunogenic abscopal effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Immunogenicity and immunomodulatory properties of hepatocyte-like cells derived from human amniotic epithelial cells.

PubMed

Tee, Jing Yang; Vaghjiani, Vijesh; Liu, Yu Han; Murthi, Padma; Chan, James; Manuelpillai, Ursula

2013-01-01

Hepatocyte transplantation is being trialled as an alternative to whole organ transplant for patients with acute liver failure and liver specific metabolic diseases. Due to the scarcity of human hepatocytes, hepatocyte-like cells (HLC) generated from stem cells may become a viable alternative to hepatocyte transplantation. Human amniotic epithelial cells (hAEC) from the placenta have stem cell-like properties and can be differentiated into HLC. Naïve hAEC have low immunogenicity and exert immunomodulatory effects that may facilitate allogeneic transplantation. However, whether the immunogenicity and immunomodulatory properties alter with differentiation into HLC are unknown. We further characterized HLC generated from hAEC, examined changes in human leucocyte antigens (HLA) and co-stimulatory molecules and effects exerted by the HLC on human peripheral blood mononuclear cells (PBMC). HLC derived from hAEC expressed proteins found in hepatocytes, had CYP3A4 drug metabolizing enzyme activity and secreted urea. IFN-γ treatment increased HLA Class IA, Class II and co-stimulatory molecule CD40 expression in the HLC. IFN-γ treated HLC stimulated proliferation of PBMC in one-way mixed lymphocyte reactions and were more immunogenic than undifferentiated hAEC. However, the HLC showed immunomodulatory properties and inhibited mitogen induced PBMC proliferation in vitro. PBMC proliferation may have been inhibited by IL-6, TGF-β1, PGE2 and HLA-G secreted by the HLC. The retention of immunomodulatory properties may enable HLC grafts to survive for longer periods despite the immunogenicity of the HLC.

2017 White Paper: rise of hybrid LBA/LCMS immunogenicity assays (Part 2: hybrid LBA/LCMS biotherapeutics, biomarkers & immunogenicity assays and regulatory agencies' inputs).

PubMed

Neubert, Hendrik; Song, An; Lee, Anita; Wei, Cong; Duggan, Jeff; Xu, Keyang; Woolf, Eric; Evans, Chris; Palandra, Joe; Laterza, Omar; Amur, Shashi; Berger, Isabella; Bustard, Mark; Cancilla, Mark; Chen, Shang-Chiung; Cho, Seongeun Julia; Ciccimaro, Eugene; Cludts, Isabelle; Cocea, Laurent; D'Arienzo, Celia; Danan-Leon, Lieza; Donato, Lorella Di; Garofolo, Fabio; Haidar, Sam; Ishii-Watabe, Akiko; Jiang, Hao; Kadavil, John; Kassim, Sean; Kurki, Pekka; Blaye, Olivier Le; Liu, Kai; Mathews, Rod; Lima Santos, Gustavo Mendes; Niwa, Makoto; Pedras-Vasconcelos, João; Qian, Mark; Rago, Brian; Saad, Ola; Saito, Yoshiro; Savoie, Natasha; Su, Dian; Szapacs, Matthew; Tampal, Nilufer; Vinter, Stephen; Wang, Jian; Welink, Jan; Whale, Emma; Wilson, Amanda; Xue, Y-J

2017-12-01

The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid ligand binding assay (LBA)/LCMS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations for biotherapeutics, biomarkers and immunogenicity assays using hybrid LBA/LCMS and regulatory agencies' inputs. Part 1 (LCMS for small molecules, peptides and small molecule biomarkers) and Part 3 (LBA: immunogenicity, biomarkers and pharmacokinetic assays) are published in Volume 9 of Bioanalysis, issues 22 and 24 (2017), respectively.

Development of an FHbp-CTB holotoxin-like chimera and the elicitation of bactericidal antibodies against serogroup B Neisseria meningitidis.

PubMed

Price, Gregory A; Bash, Margaret C

2018-01-29

The Neisseria meningitidis factor H binding protein (FHbp) is an important virulence factor and vaccine antigen contained in both USA licensed serogroup B meningococcal vaccines. Recent studies in human factor H (hFH) transgenic mice suggest that hFH-FHbp interactions lower FHbp-elicited immunogenicity. To provide tools with which to characterize and potentially improve FHbp immunogenicity, we developed an FHbp-cholera holotoxin-like chimera vaccine expression system in Escherichia coli that utilizes cholera toxin B (CTB) as both a scaffold and adjuvant for FHbp. We developed FHbp-CTB chimeras using a wild-type (WT) FHbp and a low hFH-binding FHbp mutant R41S. Both chimeras bound to G M1 ganglioside and were recognized by the FHbp-specific monoclonal antibody JAR4. The R41S mutant had greatly reduced hFH binding compared to the WT FHbp-CTB chimera. WT and R41S FHbp-CTB chimeric antigens were compared to equimolar amounts of FHbp admixed with CTB or FHbp alone in mouse immunogenicity studies. The chimeras were significantly more immunogenic than FHbp alone or mixed with CTB, and elicited bactericidal antibodies against a panel of MenB isolates. This study demonstrates a unique and simple method for studying FHbp immunogenicity. The chimeric approach may facilitate studies of other protein-based antigens targeting pathogenic Neisseria and lay groundwork for the development of new protein based vaccines against meningococcal and gonococcal disease. Published by Elsevier Ltd.

Preparation, characterization, and immunogenicity of Haemophilus influenzae type b polysaccharide-protein conjugates

PubMed Central

1980-01-01

A method is presented for covalently bonding Haemophilus influenzae type b capsular polysaccharide (HIB Ps) to several proteins. The method is efficient and relies upon the use of adipic dihydrazide as a spacer between the capsular polysaccharide and the carrier protein. In contrast to the poor immunogenicity of the purified HIB Ps in mice and rabbits, the HIB Ps-protein conjugates induced serum anti-type b antibodies having bactericidal activity at levels shown to be protective in humans when low doses were injected subcutaneously in a saline solution. The antibody response in mice was related to the dose of the conjugates, increased with the number of injections, and could be primed by the previous injection of the carrier protein. The HIB Ps- protein conjugates were immunogenic in three different mouse strains. The importance of the carrier molecule for the enhanced immunogenicity of the HIB Ps-protein conjugates was shown by the failure of HIB Ps hybrids prepared with either the homologous polysaccharide or pneumococcus type 3 polysaccharide to induce antibodie in mice. Rabbits injected with the HIB Ps-protein conjugates emulsified in Freund's adjuvant produced high levels of serum anti-type b antibodies which induced a bactericidal effect upon H. influenzae type b organisms. It is proposed that the HIB Ps component of the polysaccharide protein conjugates has been converted to a thymic-dependent immunogen. This method may be used to prepare protein-polysaccharide conjugates with HIB Ps and other polysaccharides to be considered for human use. PMID:6967514

Alpha Particles Induce Autophagy in Multiple Myeloma Cells.

PubMed

Gorin, Jean-Baptiste; Gouard, Sébastien; Ménager, Jérémie; Morgenstern, Alfred; Bruchertseifer, Frank; Faivre-Chauvet, Alain; Guilloux, Yannick; Chérel, Michel; Davodeau, François; Gaschet, Joëlle

2015-01-01

Radiation emitted by the radionuclides in radioimmunotherapy (RIT) approaches induce direct killing of the targeted cells as well as indirect killing through the bystander effect. Our research group is dedicated to the development of α-RIT, i.e., RIT using α-particles especially for the treatment of multiple myeloma (MM). γ-irradiation and β-irradiation have been shown to trigger apoptosis in tumor cells. Cell death mode induced by (213)Bi α-irradiation appears more controversial. We therefore decided to investigate the effects of (213)Bi on MM cell radiobiology, notably cell death mechanisms as well as tumor cell immunogenicity after irradiation. Murine 5T33 and human LP-1 MM cell lines were used to study the effects of such α-particles. We first examined the effects of (213)Bi on proliferation rate, double-strand DNA breaks, cell cycle, and cell death. Then, we investigated autophagy after (213)Bi irradiation. Finally, a coculture of dendritic cells (DCs) with irradiated tumor cells or their culture media was performed to test whether it would induce DC activation. We showed that (213)Bi induces DNA double-strand breaks, cell cycle arrest, and autophagy in both cell lines, but we detected only slight levels of early apoptosis within the 120 h following irradiation in 5T33 and LP-1. Inhibition of autophagy prevented (213)Bi-induced inhibition of proliferation in LP-1 suggesting that this mechanism is involved in cell death after irradiation. We then assessed the immunogenicity of irradiated cells and found that irradiated LP-1 can activate DC through the secretion of soluble factor(s); however, no increase in membrane or extracellular expression of danger-associated molecular patterns was observed after irradiation. This study demonstrates that (213)Bi induces mainly necrosis in MM cells, low levels of apoptosis, and autophagy that might be involved in tumor cell death.

Gene transfer preferentially selects MHC class I positive tumour cells and enhances tumour immunogenicity.

PubMed

Hacker, Ulrich T; Schildhauer, Ines; Barroso, Margarita Céspedes; Kofler, David M; Gerner, Franz M; Mysliwietz, Josef; Buening, Hildegard; Hallek, Michael; King, Susan B S

2006-05-01

The modulated expression of MHC class I on tumour tissue is well documented. Although the effect of MHC class I expression on the tumorigenicity and immunogenicity of MHC class I negative tumour cell lines has been rigorously studied, less is known about the validity of gene transfer and selection in cell lines with a mixed MHC class I phenotype. To address this issue we identified a C26 cell subline that consists of distinct populations of MHC class I (H-2D/K) positive and negative cells. Transient transfection experiments using liposome-based transfer showed a lower transgene expression in MHC class I negative cells. In addition, MHC class I negative cells were more sensitive to antibiotic selection. This led to the generation of fully MHC class I positive cell lines. In contrast to C26 cells, all transfectants were rejected in vivo and induced protection against the parental tumour cells in rechallenge experiments. Tumour cell specificity of the immune response was demonstrated in in vitro cytokine secretion and cytotoxicity assays. Transfectants expressing CD40 ligand and hygromycin phosphotransferase were not more immunogenic than cells expressing hygromycin resistance alone. We suggest that the MHC class I positive phenotype of the C26 transfectants had a bearing on their immunogenicity, because selected MHC class I positive cells were more immunogenic than parental C26 cells and could induce specific anti-tumour immune responses. These data demonstrate that the generation of tumour cell transfectants can lead to the selection of subpopulations that show an altered phenotype compared to the parental cell line and display altered immunogenicity independent of selection marker genes or other immune modulatory genes. Our results show the importance of monitoring gene transfer in the whole tumour cell population, especially for the evaluation of in vivo therapies targeted to heterogeneous tumour cell populations.

Safety and immunogenicity of a CRM or TT conjugated meningococcal vaccine in healthy toddlers.

PubMed

Bona, Gianni; Castiglia, Paolo; Zoppi, Giorgio; de Martino, Maurizio; Tasciotti, Annaelisa; D'Agostino, Diego; Han, Linda; Smolenov, Igor

2016-06-17

MenACWY-CRM (Menveo(®); GlaxoSmithKline) and MenACWY-TT (Nimenrix(®); Pfizer) are two meningococcal vaccines licensed in the European Union for use in both children and adults. While both vaccines target meningococcal serogroups A, C, W and Y, immunogenicity and reactogenicity of these quadrivalent meningococcal conjugate vaccines may differ due to differences in formulation processes and chemical structure. Yet data on the comparability of these two vaccines are limited. The reactogenicity and immunogenicity of one dose of either MenACWY-CRM or MenACWY-TT were evaluated in healthy toddlers aged 12-15 months. Immunogenicity was assessed using serum bactericidal antibody assays (SBA) with human (hSBA) and rabbit (rSBA) complement. A total of 202 children aged 12-15 months were enrolled to receive one dose of MenACWY-CRM or MenACWY-TT. Similar numbers of subjects reported solicited reactions within 7 days following either vaccination. Tenderness at the injection site was the most common local reaction. Systemic reactions reported were similar for both vaccines and mostly mild to moderate in severity: irritability, sleepiness and change in eating habits were most commonly reported. Immunogenicity at 1 month post-vaccination was generally comparable for both vaccines across serogroups. At 6 months post-vaccination antibody persistence against serogroups C, W, and Y was substantial for both vaccines, as measured by both assay methodologies. For serogroup A, hSBA titers declined in both groups, while rSBA titers remained high. Despite differences in composition, the MenACWY-CRM and MenACWY-TT vaccines have comparable reactogenicity and immunogenicity profiles. Immediate immune responses and short-term antibody persistence were largely similar between groups. Both vaccines were well-tolerated and no safety concerns were identified. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evaluation of the immunogenicity and protective effects of a trivalent chimeric norovirus P particle immunogen displaying influenza HA2 from subtypes H1, H3 and B

PubMed Central

Gong, Xin; Yin, He; Shi, Yuhua; He, Xiaoqiu; Yu, Yongjiao; Guan, Shanshan; Kuai, Ziyu; Haji, Nasteha M; Haji, Nafisa M; Kong, Wei; Shan, Yaming

2016-01-01

The ectodomain of the influenza A virus (IAV) hemagglutinin (HA) stem is highly conserved across strains and has shown promise as a universal influenza vaccine in a mouse model. In this study, potential B-cell epitopes were found through sequence alignment and epitope prediction in a stem fragment, HA2:90-105, which is highly conserved among virus subtypes H1, H3 and B. A norovirus (NoV) P particle platform was used to express the HA2:90-105 sequences from subtypes H1, H3 and B in loops 1, 2 and 3 of the protrusion (P) domain, respectively. Through mouse immunization and microneutralization assays, the immunogenicity and protective efficacy of the chimeric NoV P particle (trivalent HA2-PP) were tested against infection with three subtypes (H1N1, H3N2 and B) of IAV in Madin–Darby canine kidney cells. The protective efficacy of the trivalent HA2-PP was also evaluated preliminarily in vivo by virus challenge in the mouse model. The trivalent HA2-PP immunogen induced significant IgG antibody responses, which could be enhanced by a virus booster vaccination. Moreover, the trivalent HA2-PP immunogen also demonstrated in vitro neutralization of the H3 and B viruses, and in vivo protection against the H3 virus. Our results support the notion that a broadly protective vaccine approach using an HA2-based NoV P particle platform can provide cross-protection against challenge viruses of different IAV subtypes. The efficacy of the immunogen should be further enhanced for practicality, and a better understanding of the protective immune mechanism will be critical for the development of HA2-based multivalent vaccines. PMID:27222326

Diverse manifestations of tumorigenicity and immunogenicity displayed by the poorly immunogenic B16-BL6 melanoma transduced with cytokine genes.

PubMed

Arca, M J; Krauss, J C; Strome, S E; Cameron, M J; Chang, A E

1996-05-01

We evaluated the in vivo response to the poorly immunogenic B16-BL6 (BL6) murine melanoma genetically altered to secrete interleukin-2 (IL-2), IL-4, interferon gamma (IFN gamma) and granulocyte/macrophage-colony-stimulating factor (GM-CSF). Three parameters were evaluated: (1) tumorigenicity, (2) vaccination of naive animals, and (3) assessment of antitumor reactivity of T cells derived from tumor-draining lymph nodes (TDLN). Secretion of IL-2 abrogated the tumorigenicity of BL6, while IFN gamma and IL-4 partially reduced tumorigenicity, and GM-CSF had no effect. Protective immunity to wild-type tumor challenge could not be achieved by vaccination with irradiated cytokine-secreting tumors, although IL-2 and IL-4 secretion appeared to retard the growth of the challenge inoculum significantly. An alternative method to evaluate the immunogenicity of the cytokine-secreting tumors was to measure the ability of T cells obtained from TDLN to mediate regression of wild-type tumor in adoptive immunotherapy. Neither IL-2 nor IFN gamma secretion resulted in the induction of immune T cells. By contrast, GM-CSF and IL-4 secretion were found to induce immune T cells in the TDLN with GM-CSF being superior to IL-4. The combined secretion of GM-CSF and IL-4 did not lead to enhanced induction of immune T cells. GM-CSF secretion was found to upregulate B7-1 expression in TDLN, consistent with an increase in the population of antigen-presenting cells. These studies demonstrated that reduced tumorigenicity by cytokine secretion did not correlate with increased immunogenicity. With the cytokines examined, there was limited capability of developing protective immunity against the BL6 tumor. Nevertheless, GM-CSF and IL-4 secretion significantly enhanced T cell immune reactivity to the poorly immunogenic BL6 tumor.

Preclinical evaluation of a Haemophilus influenzae type b conjugate vaccine process intended for technology transfer.

PubMed

Hamidi, Ahd; Verdijk, Pauline; Kreeftenberg, Hans

2014-01-01

Introduction of Haemophilus influenzae type b (Hib) vaccine in low- and middle-income countries has been limited by cost and availability of Hib conjugate vaccines for a long time. It was previously recognized by the Institute for Translational Vaccinology (Intravacc, originating from the former Vaccinology Unit of the National Institute of Public Health [RIVM] and the Netherlands Vaccine Institute [NVI]) that local production of a Hib conjugate vaccine would increase the affordability and sustainability of the vaccine and thereby help to speed up Hib introduction in these countries. A new affordable and a non-infringing production process for a Hib conjugate vaccine was developed, including relevant quality control tests, and the technology was transferred to a number of vaccine manufacturers in India, Indonesia, and China. As part of the Hib technology transfer project managed by Intravacc, a preclinical toxicity study was conducted in the Netherlands to test the safety and immunogenicity of this new Hib conjugate vaccine. The data generated by this study were used by the technology transfer partners to accelerate the clinical development of the new Hib conjugate vaccine. A repeated dose toxicity and local tolerance study in rats was performed to assess the reactogenicity and immunogenicity of a new Hib conjugate vaccine compared to a licensed vaccine. The results showed that the vaccine was well tolerated and immunogenic in rats, no major differences in both safety and immunogenicity in rats were found between the vaccine produced according to the production process developed by Intravacc and the licensed one. Rats may be useful to verify the immunogenicity of Hib conjugate vaccines and for preclinical evaluation. In general, nonclinical evaluation of the new Hib conjugate vaccine, including this proof of concept (safety and immunogenicity study in rats), made it possible for technology transfer partners, having implemented the original process with no changes in the manufacturing process and vaccine formulation, to start directly with phase 1 clinical trials.

Contribution of enhanced engagement of antigen presentation machinery to the clinical immunogenicity of a human interleukin (IL)-21 receptor-blocking therapeutic antibody.

PubMed

Xue, L; Hickling, T; Song, R; Nowak, J; Rup, B

2016-01-01

Reliable risk assessment for biotherapeutics requires accurate evaluation of risk factors associated with immunogenicity. Immunogenicity risk assessment tools were developed and applied to investigate the immunogenicity of a fully human therapeutic monoclonal antibody, ATR-107 [anti-interleukin (IL)-21 receptor] that elicited anti-drug antibodies (ADA) in 76% of healthy subjects in a Phase 1 study. Because the ATR-107 target is expressed on dendritic cells (DCs), the immunogenicity risk related to engagement with DC and antigen presentation pathways was studied. Despite the presence of IL-21R on DCs, ATR-107 did not bind to the DCs more extensively than the control therapeutic antibody (PF-1) that had elicited low clinical ADA incidence. However, ATR-107, but not the control therapeutic antibody, was translocated to the DC late endosomes, co-localized with intracellular antigen-D related (HLA-DR) molecules and presented a dominant T cell epitope overlapping the complementarity determining region 2 (CDR2) of the light chain. ATR-107 induced increased DC activation exemplified by up-regulation of DC surface expression of CD86, CD274 (PD-L1) and CD40, increased expansion of activated DC populations expressing CD86(hi), CD40(hi), CD83(hi), programmed death ligand 1 (PD-L1)(hi), HLA-DR(hi) or CCR7(hi), as well as elevated secretion of tumour necrosis factor (TNF)-α by DCs. DCs exposed to ATR-107 stimulated an autologous T cell proliferative response in human donor cells, in concert with the detection of immunoglobulin (Ig)G-type anti-ATR-107 antibody response in clinical samples. Collectively, the enhanced engagement of antigen presentation machinery by ATR-107 was suggested. The approaches and findings described in this study may be relevant to identifying lower immunogenicity risk targets and therapeutic molecules. © 2015 British Society for Immunology.

Phase I/II, open-label trial of safety and immunogenicity of meningococcal (groups A, C, Y, and W-135) polysaccharide diphtheria toxoid conjugate vaccine in human immunodeficiency virus-infected adolescents.

PubMed

Siberry, George K; Williams, Paige L; Lujan-Zilbermann, Jorge; Warshaw, Meredith G; Spector, Stephen A; Decker, Michael D; Heckman, Barbara E; Demske, Emily F; Read, Jennifer S; Jean-Philippe, Patrick; Kabat, William; Nachman, Sharon

2010-05-01

Quadrivalent meningococcal polysaccharide conjugate vaccine (MCV4) is routinely recommended for healthy youth in the United States, but there are no data about its use in HIV-infected people. P1065 is a Phase I/II trial of MCV4 safety and immunogenicity in HIV-infected children and youth performed at 27 US sites of the IMPAACT network. All youth (11-24 years old) received 1 dose of open-label MCV4 at entry. Standardized questionnaires were used to evaluate safety. Baseline protective immunity was defined as rabbit serum bactericidal antibody (rSBA) titer > or = 1:128. Immunogenic response was defined as a > or = 4-fold rise in rSBA against each meningococcal serogroup. Multivariable logistic regression analysis was used to evaluate the association of demographic and clinical characteristics on immunogenic response to serogroup C. Among 319 subjects who received MCV4, 10 (3.1%) reported immediate adverse events which were local and mild, and 7 (2.2%) experienced Grade > or = 3 adverse events, unrelated to vaccine. The 305 subjects with serologic data had a median age of 17 years and were 59% male, 50% Black, and 38% Latino. Subjects were stratified by entry CD4%: 12%, CD4 <15%; 40%, 15% to 24%; and 48%, > or = 25%. Baseline protective immunity varied by serogroup: A, 41%; C, 11%; W-135, 15%; Y, 35% The immunogenic response rates to serogroups A, C, W-135, and Y were 68%, 52%, 73%, and 63%, respectively. In multivariable logistic regression models, lower entry CD4%, higher entry viral load, and CDC Class B/C diagnosis were associated with significantly lower odds of response to serogroup C. Many HIV-infected youth naturally acquire meningococcal immunity. MCV4 is safe and immunogenic in HIV-infected youth, but response rates are lower than in healthy youth, particularly for those with more advanced HIV clinical, immunologic, and virologic status.

Immunogenicity, safety, and efficacy of abatacept administered subcutaneously with or without background methotrexate in patients with rheumatoid arthritis: results from a phase III, international, multicenter, parallel-arm, open-label study.

PubMed

Nash, Peter; Nayiager, Sauithree; Genovese, Mark C; Kivitz, Alan J; Oelke, Kurt; Ludivico, Charles; Palmer, William; Rodriguez, Cristian; Delaet, Ingrid; Elegbe, Ayanbola; Corbo, Michael

2013-05-01

To evaluate the impact of concomitant methotrexate (MTX) on subcutaneous (SC) abatacept immunogenicity, and to assess safety and efficacy. This phase III, open-label study had a 4-month short-term (ST) period and an ongoing long-term extension (LTE) period. Rheumatoid arthritis patients were stratified to receive SC abatacept (125 mg/week) with (combination) or without MTX (monotherapy), with no intravenous loading dose; patients receiving monotherapy could add MTX in the LTE period. Immunogenicity (percentage of anti-abatacept antibody-positive patients) was assessed. ST and LTE period data are reported, including efficacy through LTE month 14 and safety through LTE month 20. Ninety-six of 100 enrolled patients completed the ST period; 3.9% (combination) and 4.1% of patients (monotherapy) developed transient immunogenicity, and no patients were antibody positive at month 4. Serious adverse events (SAEs) were reported in 3.9% (combination) and 6.1% of patients (monotherapy); 5.9% (combination) and 8.2% of patients (monotherapy) experienced SC injection reactions, and all were mild in intensity. Mean 28-joint Disease Activity Score (DAS28) changes were -1.67 (95% confidence interval [95% CI] -2.06, -1.28; combination) and -1.94 (95% CI -2.46, -1.42; monotherapy) at month 4. Ninety patients entered and were treated in the LTE period; 83.3% (75 of 90) remained ongoing at month 24. One LTE-treated patient (1.1%) developed immunogenicity, 14.4% of patients experienced SAEs, and no SC injection reactions were reported. For patients entering the LTE period, mean DAS28 changes from baseline were -1.84 (95% CI -2.23, -1.34; combination) and -2.86 (95% CI -3.46, -2.27; monotherapy) at month 18. SC abatacept did not elicit immunogenicity associated with loss of safety or efficacy, either with or without MTX. Copyright © 2013 by the American College of Rheumatology.

Interference of Monovalent, Bivalent, and Trivalent Oral Poliovirus Vaccines on Monovalent Rotavirus Vaccine Immunogenicity in Rural Bangladesh.

PubMed

Emperador, Devy M; Velasquez, Daniel E; Estivariz, Concepcion F; Lopman, Ben; Jiang, Baoming; Parashar, Umesh; Anand, Abhijeet; Zaman, Khalequ

2016-01-15

Trivalent oral poliovirus vaccine (OPV) is known to interfere with monovalent rotavirus vaccine (RV1) immunogenicity. The interference caused by bivalent and monovalent OPV formulations, which will be increasingly used globally in coming years, has not been examined. We conducted a post hoc analysis to assess the effect of coadministration of different OPV formulations on RV1 immunogenicity. Healthy infants in Matlab, Bangladesh, were randomized to receive 3 doses of monovalent OPV type 1 or bivalent OPV types 1 and 3 at either 6, 8, and 10 or 6, 10, and 14 weeks of age or trivalent OPV at 6, 10, and 14 weeks of age. All infants received 2 doses of RV1 at about 6 and 10 weeks of age. Concomitant administration was defined as RV1 and OPV given on the same day; staggered administration as RV1 and OPV given ≥1 day apart. Rotavirus seroconversion was defined as a 4-fold rise in immunoglobulin A titer from before the first RV1 dose to ≥3 weeks after the second RV1 dose. There were no significant differences in baseline RV1 immunogenicity among the 409 infants included in the final analysis. Infants who received RV1 and OPV concomitantly, regardless of OPV formulation, were less likely to seroconvert (47%; 95% confidence interval, 39%-54%) than those who received both vaccines staggered ≥1 day (63%; 57%-70%; P < .001). For staggered administration, we found no evidence that the interval between RV1 and OPV administration affected RV1 immunogenicity. Coadministration of monovalent, bivalent, or trivalent OPV seems to lower RV1 immunogenicity. NCT01633216. Published by Oxford University Press for the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

CD4 T cell-mediated masking effects of the immunogenicity of tumor-associated antigens are qualitatively and quantitatively different depending on the individual antigens.

PubMed

Okano, Shinji; Matsumoto, Yoshihiro; Yoshiya, Shohei; Yamashita, Yo-ichi; Harimoto, Norifumi; Ikegami, Toru; Shirabe, Ken; Harada, Mamoru; Yoshikai, Yasunobu; Maehara, Yoshihiko

2013-01-01

The use of cancer immunotherapy as part of multidisciplinary therapies for cancer is a promising strategy for the cure of advanced cancer patients. In cancer immunotherapy, the effective priming of tumor-associated antigen (TAA)-specific CD8+ T cells is essential, and therefore, the appropriate selection of the best peptide for targeting the cancer is a most important concern. One criticism in the selection of a TAA is the immunogenicity of the TAA, the vaccination of which effectively elicits clinical responses. However, the critical basic immunological factors that affect the differences in the immunogenicity of TAAs remain to be elucidated. Here we found that CD4 T-cell responses suppressed the immunogenicity of the concomitant TAA in a murine melanoma model in which intratumoral activated dendritic therapy (ITADT) was used for treatment of the established cancer, and we observed that the antitumor effects were largely dependent on the CD8 T-cell response. CD4 T-cell depletion simply enhanced the tyrosinase-related protein (TRP)-2(180-188) peptide-specific cytotoxic T-cell (CTL) responses, and CD4 T-cell depletion provided immunogenicity for mgp100(25-33) peptide, to which a CTL response could not be detected at all in CD4 T-cell-intact mice in the early therapeutic phase. Further, the mgp100(25-33) peptide-specific CTL response again became undetectable after the recovery of CD4 T cells in previously CD4-depleted, tumor-eradicated mice, whereas the TRP-2(180-188) peptide-specific CTL response was still much stronger in CD4-depleted mice than in CD4-intact mice. These findings suggest that the CD4 T cell-mediated masking effects of the immunogenicity of tumor-associated antigens are qualitatively and quantitatively different depending on the individual antigens.

Comparison of the immunogenicity and safety of the conventional subunit, MF59-adjuvanted, and intradermal influenza vaccines in the elderly.

PubMed

Seo, Yu Bin; Choi, Won Suk; Lee, Jacob; Song, Joon Young; Cheong, Hee Jin; Kim, Woo Joo

2014-07-01

The influenza vaccination is known as the most effective method for preventing influenza infection and its complications in the elderly. Conventional subunit (Agrippal S1; Novartis), MF59-adjuvanted (Fluad; Novartis), and intradermal (IDflu15; Sanofi Pasteur) influenza vaccines are widely used throughout South Korea. However, few comparative studies evaluating the safety and immunogenicity of these vaccines are available. Prior to the beginning of the 2011-2012 influenza season, 335 healthy elderly volunteers randomly received one of three seasonal trivalent influenza vaccines, the conventional subunit, MF59-adjuvanted, or intradermal influenza vaccine. Serum hemagglutination-inhibiting antibody levels were measured at the time of vaccination and at 1 and 6 months after vaccination. Adverse events were recorded prospectively. A total of 113 conventional subunit, 111 MF59-adjuvanted, and 111 intradermal influenza vaccine volunteers were followed up during a 6-month postvaccination period. One month after vaccination, all three vaccines satisfied Committee for Medical Products for Human Use (CHMP) immunogenicity criteria for the A/H1N1 and A/H3N2 strains but not for the B strain. Compared with the subunit vaccine, the intradermal vaccine exhibited noninferiority, while the MF59-adjuvanted vaccine exhibited superiority. Furthermore, the MF59-adjuvanted vaccine was more immunogenic against the A/H3N2 strain than was the subunit vaccine up to 6 months postvaccination. The most common local and systemic reactions to the conventional subunit, MF59-adjuvanted, and intradermal influenza vaccines were pain at the injection site (7.1%, 10.8%, and 6.3%, respectively) and generalized myalgia (0.9%, 8.1%, and 5.4%, respectively). Local and systemic reactions were similar among the three vaccine groups. MF59-adjuvanted vaccine exhibited superior immunogenicity compared with a conventional subunit vaccine and had a comparable safety profile. For older adults, the MF59-adjuvanted vaccine is preferable for providing superior immunogenicity. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Comparison of the safety and immunogenicity of live attenuated and inactivated hepatitis A vaccine in healthy Chinese children aged 18 months to 16 years: results from a randomized, parallel controlled, phase IV study.

PubMed

Ma, F; Yang, J; Kang, G; Sun, Q; Lu, P; Zhao, Y; Wang, Z; Luo, J; Wang, Z

2016-09-01

For large-scale immunization of children with hepatitis A (HA) vaccines in China, accurately designed studies comparing the safety and immunogenicity of the live attenuated HA vaccine (HA-L) and inactivated HA vaccine (HA-I) are necessary. A randomized, parallel controlled, phase IV clinical trial was conducted with 6000 healthy children aged 18 months to 16 years. HA-L or HA-I was administered at a ratio of 1: 1 to randomized selected participants. The safety and immunogenicity were evaluated. Both HA-L and HA-I were well tolerated by all participants. The immunogenicity results showed that the seroconversion rates (HA-L versus HA-I: 98.0% versus 100%, respectively, p >0.05), and geometric mean concentrations in participants negative for antibodies against HA virus IgG (anti-HAV IgG) before vaccination did not differ significantly between the two types of vaccines (HA-L versus HA-I first dose: 898.9 versus 886.2 mIU/mL, respectively, p >0.05). After administration of the booster dose of HA-I, the geometric mean concentrations of anti-HAV IgG (HA-I booster dose: 2591.2 mIU/mL) was higher than that after the first dose (p <0.05) and that reported in participants administered HA-L (p <0.05). Additionally, 12 (25%) of the 48 randomized selected participants who received HA-L tested positive for HA antigen in stool samples. Hence, both HA-L and HA-I could provide acceptable immunogenicity in children. The effects of long-term immunogenicity after natural exposure to wild-type HA virus and the possibility of mutational shifts of the live vaccine virus in the field need to be studied in more detail. Copyright © 2016. Published by Elsevier Ltd.

A Recombinant Respiratory Syncytial Virus Vaccine Candidate Attenuated by a Low-Fusion F Protein Is Immunogenic and Protective against Challenge in Cotton Rats

PubMed Central

Rostad, Christina A.; Stobart, Christopher C.; Gilbert, Brian E.; Pickles, Ray J.; Hotard, Anne L.; Meng, Jia; Blanco, Jorge C. G.; Moin, Syed M.; Graham, Barney S.; Piedra, Pedro A.

2016-01-01

ABSTRACT Although respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, a safe and effective vaccine is not yet available. Live-attenuated vaccines (LAVs) are the most advanced vaccine candidates in RSV-naive infants. However, designing an LAV with appropriate attenuation yet sufficient immunogenicity has proven challenging. In this study, we implemented reverse genetics to address these obstacles with a multifaceted LAV design that combined the codon deoptimization of genes for nonstructural proteins NS1 and NS2 (dNS), deletion of the small hydrophobic protein (ΔSH) gene, and replacement of the wild-type fusion (F) protein gene with a low-fusion RSV subgroup B F consensus sequence of the Buenos Aires clade (BAF). This vaccine candidate, RSV-A2-dNS-ΔSH-BAF (DB1), was attenuated in two models of primary human airway epithelial cells and in the upper and lower airways of cotton rats. DB1 was also highly immunogenic in cotton rats and elicited broadly neutralizing antibodies against a diverse panel of recombinant RSV strains. When vaccinated cotton rats were challenged with wild-type RSV A, DB1 reduced viral titers in the upper and lower airways by 3.8 log10 total PFU and 2.7 log10 PFU/g of tissue, respectively, compared to those in unvaccinated animals (P < 0.0001). DB1 was thus attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. DB1 is the first RSV LAV to incorporate a low-fusion F protein as a strategy to attenuate viral replication and preserve immunogenicity. IMPORTANCE RSV is a leading cause of infant hospitalizations and deaths. The development of an effective vaccine for this high-risk population is therefore a public health priority. Although live-attenuated vaccines have been safely administered to RSV-naive infants, strategies to balance vaccine attenuation with immunogenicity have been elusive. In this study, we introduced a novel strategy to attenuate a recombinant RSV vaccine by incorporating a low-fusion, subgroup B F protein in the genetic background of codon-deoptimized nonstructural protein genes and a deleted small hydrophobic protein gene. The resultant vaccine candidate, DB1, was attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. PMID:27279612

A Recombinant Respiratory Syncytial Virus Vaccine Candidate Attenuated by a Low-Fusion F Protein Is Immunogenic and Protective against Challenge in Cotton Rats.

PubMed

Rostad, Christina A; Stobart, Christopher C; Gilbert, Brian E; Pickles, Ray J; Hotard, Anne L; Meng, Jia; Blanco, Jorge C G; Moin, Syed M; Graham, Barney S; Piedra, Pedro A; Moore, Martin L

2016-08-15

Although respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, a safe and effective vaccine is not yet available. Live-attenuated vaccines (LAVs) are the most advanced vaccine candidates in RSV-naive infants. However, designing an LAV with appropriate attenuation yet sufficient immunogenicity has proven challenging. In this study, we implemented reverse genetics to address these obstacles with a multifaceted LAV design that combined the codon deoptimization of genes for nonstructural proteins NS1 and NS2 (dNS), deletion of the small hydrophobic protein (ΔSH) gene, and replacement of the wild-type fusion (F) protein gene with a low-fusion RSV subgroup B F consensus sequence of the Buenos Aires clade (BAF). This vaccine candidate, RSV-A2-dNS-ΔSH-BAF (DB1), was attenuated in two models of primary human airway epithelial cells and in the upper and lower airways of cotton rats. DB1 was also highly immunogenic in cotton rats and elicited broadly neutralizing antibodies against a diverse panel of recombinant RSV strains. When vaccinated cotton rats were challenged with wild-type RSV A, DB1 reduced viral titers in the upper and lower airways by 3.8 log10 total PFU and 2.7 log10 PFU/g of tissue, respectively, compared to those in unvaccinated animals (P < 0.0001). DB1 was thus attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. DB1 is the first RSV LAV to incorporate a low-fusion F protein as a strategy to attenuate viral replication and preserve immunogenicity. RSV is a leading cause of infant hospitalizations and deaths. The development of an effective vaccine for this high-risk population is therefore a public health priority. Although live-attenuated vaccines have been safely administered to RSV-naive infants, strategies to balance vaccine attenuation with immunogenicity have been elusive. In this study, we introduced a novel strategy to attenuate a recombinant RSV vaccine by incorporating a low-fusion, subgroup B F protein in the genetic background of codon-deoptimized nonstructural protein genes and a deleted small hydrophobic protein gene. The resultant vaccine candidate, DB1, was attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Proteomics and bioinformatics strategies to design countermeasures against infectious threat agents.

PubMed

Khan, Akbar S; Mujer, Cesar V; Alefantis, Timothy G; Connolly, Joseph P; Mayr, Ulrike Beate; Walcher, Petra; Lubitz, Werner; Delvecchio, Vito G

2006-01-01

The potential devastation resulting from an intentional outbreak caused by biological warfare agents such as Brucella abortus and Bacillus anthracis underscores the need for next generation vaccines. Proteomics, genomics, and systems biology approaches coupled with the bacterial ghost (BG) vaccine delivery strategy offer an ideal approach for developing safer, cost-effective, and efficacious vaccines for human use in a relatively rapid time frame. Critical to any subunit vaccine development strategy is the identification of a pathogen's proteins with the greatest potential of eliciting a protective immune response. These proteins are collectively referred to as the pathogen's immunome. Proteomics provides high-resolution identification of these immunogenic proteins using standard proteomic technologies, Western blots probed with antisera from infected patients, and the pathogen's sequenced and annotated genome. Selected immunoreactive proteins can be then cloned and expressed in nonpathogenic Gram-negative bacteria. Subsequently, a temperature shift or chemical induction process is initiated to induce expression of the PhiX174 E-lysis gene, whose protein product forms an E tunnel between the inner and outer membrane of the bacteria, expelling all intracellular contents. The BG vaccine system is a proven strategy developed for many different pathogens and tested in a complete array of animal models. The BG vaccine system also has great potential for producing multiagent vaccines for protection to multiple species in a single formulation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kong, Leopold; Kadam, Rameshwar U.; Giang, Erick

Hepatitis C virus (HCV) is a positive-strand RNA virus within the Flaviviridae family. The viral “spike” of HCV is formed by two envelope glycoproteins, E1 and E2, which together mediate viral entry by engaging host receptors and undergoing conformational changes to facilitate membrane fusion. While E2 can be readily produced in the absence of E1, E1 cannot be expressed without E2 and few reagents, including monoclonal antibodies, are available for study of this essential HCV glycoprotein. A human MAb to E1, IGH526, was previously reported to cross-neutralize different HCV isolates and, therefore, we sought to further characterize the IGH526 neutralizingmore » epitope to obtain information for vaccine design. Here, we found that MAb IGH526 bound to a discontinuous epitope, but with a major component corresponding to E1 residues 314-324. The crystal structure of IGH526 Fab with this E1 glycopeptide at 1.75Å resolution revealed that the antibody binds to one face of an α-helical peptide. Single mutations on the helix substantially lowered IGH526 binding but did not affect neutralization, indicating either that multiple mutations are required or that additional regions are recognized by the antibody in the context of the membrane-associated envelope oligomer. Finally, molecular dynamics simulations indicate the free peptide is flexible in solution, suggesting that it requires stabilization for use as a candidate vaccine immunogen.« less

Broadly Protective Shigella Vaccine Based on Type III Secretion Apparatus Proteins

PubMed Central

Martinez-Becerra, Francisco J.; Kissmann, Julian M.; Diaz-McNair, Jovita; Choudhari, Shyamal P.; Quick, Amy M.; Mellado-Sanchez, Gabriela; Clements, John D.

2012-01-01

Shigella spp. are food- and waterborne pathogens that cause severe diarrheal and dysenteric disease associated with high morbidity and mortality. Individuals most often affected are children under 5 years of age in the developing world. The existence of multiple Shigella serotypes and the heterogenic distribution of pathogenic strains, as well as emerging antibiotic resistance, require the development of a broadly protective vaccine. All Shigella spp. utilize a type III secretion system (TTSS) to initiate infection. The type III secretion apparatus (TTSA) is the molecular needle and syringe that form the energized conduit between the bacterial cytoplasm and the host cell to transport effector proteins that manipulate cellular processes to benefit the pathogen. IpaB and IpaD form a tip complex atop the TTSA needle and are required for pathogenesis. Because they are common to all virulent Shigella spp., they are ideal candidate antigens for a subunit-based, broad-spectrum vaccine. We examined the immunogenicity and protective efficacy of IpaB and IpaD, alone or combined, coadministered with a double mutant heat-labile toxin (dmLT) from Escherichia coli, used as a mucosal adjuvant, in a mouse model of intranasal immunization and pulmonary challenge. Robust systemic and mucosal antibody- and T cell-mediated immunities were induced against both proteins, particularly IpaB. Mice immunized in the presence of dmLT with IpaB alone or IpaB combined with IpaD were fully protected against lethal pulmonary infection with Shigella flexneri and Shigella sonnei. We provide the first demonstration that the Shigella TTSAs IpaB and IpaD are promising antigens for the development of a cross-protective Shigella vaccine. PMID:22202122

Regulated Expression of Adenoviral Vectors-Based Gene Therapies

PubMed Central

Curtin, James F.; Candolfi, Marianela; Puntel, Mariana; Xiong, Weidong; Muhammad, A. K. M.; Kroeger, Kurt; Mondkar, Sonali; Liu, Chunyan; Bondale, Niyati; Lowenstein, Pedro R.; Castro, Maria G.

2008-01-01

Summary Regulatable promoter systems allow gene expression to be tightly controlled in vivo. This is highly desirable for the development of safe, efficacious adenoviral vectors that can be used to treat human diseases in the clinic. Ideally, regulatable cassettes should have minimal gene expression in the “OFF” state, and expression should quickly reach therapeutic levels in the “ON” state. In addition, the components of regulatable cassettes should be non-toxic at physiological concentrations and should not be immunogenic, especially when treating chronic illness that requires long-lasting gene expression. In this chapter, we will describe in detail protocols to develop and validate first generation (Ad) and high-capacity adenoviral (HC-Ad) vectors that express therapeutic genes under the control of the TetON regulatable system. Our laboratory has successfully used these protocols to regulate the expression of marker genes, immune stimulatory genes, and toxins for cancer gene therapeutics, i.e., glioma that is a deadly form of brain cancer. We have shown that this third generation TetON regulatable system, incorporating a doxycycline (DOX)-sensitive rtTA2S-M2 inducer and tTSKid silencer, is non-toxic, relatively non-immunogenic, and can tightly regulate reporter transgene expression downstream of a TRE promoter from adenoviral vectors in vitro and also in vivo. PMID:18470649

A Novel Cell Wall Lipopeptide Is Important for Biofilm Formation and Pathogenicity of Mycobacterium avium subspecies paratuberculosis

PubMed Central

Wu, Chia-wei; Schmoller, Shelly K.; Bannantine, John P.; Eckstein, Torsten M.; Inamine, Julie M.; Livesey, Michael; Albrecht, Ralph; Talaat, Adel M.

2009-01-01

Biofilm formation by pathogenic bacteria plays a key role in their pathogenesis. Previously, the pstA gene was shown to be involved in the virulence of Mycobacterium avium subspecies paratuberculosis (M. ap), the causative agent of Johne's disease in cattle and a potential risk factor for Crohn's disease. Scanning electron microscopy and colonization levels of the M. ap mutant indicated that the pstA gene significantly contributes to the ability of M. ap to form biofilms. Digital measurements taken during electron microscopy identified a unique morphology for the ΔpstA mutant, which consisted of significantly shorter bacilli than the wild type. Analysis of the lipid profiles of the mycobacterial strains identified a novel lipopeptide that was present in the cell wall extracts of wild-type M. ap, but missing from the ΔpstA mutant. Interestingly, the calf infection model suggested that pstA contributes to intestinal invasion of M. ap. Furthermore, immunoblot analysis of peptides encoded by pstA identified a specific and significant level of immunogenicity. Taken together, our analysis revealed a novel cell wall component that could contribute to biofilm formation and to the virulence and immunogenicity of M. ap. Molecular tools to better control M. ap infections could be developed utilizing the presented findings. PMID:19490829

Immunogenicity and protective efficacy of the Mycobacterium tuberculosis fadD26 mutant

PubMed Central

Infante, E; Aguilar, L D; Gicquel, B; Pando, R Hernandez

2005-01-01

The Mycobacterium tuberculosis fadD26 mutant has impaired synthesis of phthiocerol dimycocerosates (DIM) and is attenuated in BALB/c mice. Survival analysis following direct intratracheal infection confirmed the attenuation: 60% survival at 4 months post-infection versus 100% mortality at 9 weeks post-infection with the wild-type strain. The fadD26 mutant induced less pneumonia and larger DTH reactions. It induced lower but progressive production of interferon (IFN)-γ, interleukin (IL)-4 and tumour necrosis factor (TNF)-α. Used as a subcutaneous vaccine 60 days before intratracheal challenge with a hypervirulent strain of M. tuberculosis (Beijing code 9501000), the mutant induced a higher level of protection than did Bacille Calmette–Guérin (BCG). Seventy per cent of the mice vaccinated with the fadD26 mutant survived at 16 weeks after challenge compared to 30% of those vaccinated with BCG. Similarly, there was less tissue damage (pneumonia) and lower colony-forming units (CFU) in the mice vaccinated with the fadD26 mutant compared to the findings in mice vaccinated with BCG. These data suggest that DIM synthesis is important for the pathogenicity of M. tuberculosis, and that inactivation of DIM synthesis can increase the immunogenicity of live vaccines, and increase their ability to protect against tuberculosis. PMID:15958066

Increased tumor localization and reduced immune response to adenoviral vector formulated with the liposome DDAB/DOPE.

PubMed

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Abu-Asab, Mones S; Tsokos, Maria; Morris, John C; Kalle, Wouter H J

2007-04-01

We aimed to increase the efficiency of adenoviral vectors by limiting adenoviral spread from the target site and reducing unwanted host immune responses to the vector. We complexed adenoviral vectors with DDAB-DOPE liposomes to form adenovirus-liposomal (AL) complexes. AL complexes were delivered by intratumoral injection in an immunocompetent subcutaneous rat tumor model and the immunogenicity of the AL complexes and the expression efficiency in the tumor and other organs was examined. Animals treated with the AL complexes had significantly lower levels of beta-galactosidase expression in systemic tissues compared to animals treated with the naked adenovirus (NA) (P<0.05). The tumor to non-tumor ratio of beta-galactosidase marker expression was significantly higher for the AL complex treated animals. NA induced significantly higher titers of adenoviral-specific antibodies compared to the AL complexes (P<0.05). The AL complexes provided protection (immunoshielding) to the adenovirus from neutralizing antibody. Forty-seven percent more beta-galactosidase expression was detected following intratumoral injection with AL complexes compared to the NA in animals pre-immunized with adenovirus. Complexing of adenovirus with liposomes provides a simple method to enhance tumor localization of the vector, decrease the immunogenicity of adenovirus, and provide protection of the virus from pre-existing neutralizing antibodies.

THE EFFECT OF MASSIVE DOSES OF $gamma$-RADIATION ON THE IMMUNOGENIC PROPERTIES OF BACTERIA OF THE INTESTINAL GROUP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tumanian, M.A.; Duplishcheva, A.P.; Sedova, T.S.

1958-01-01

Bacteria of the intestinal group were found to be killed by radiation doses of 400,000 to 600,000 r. When spore forms of bacteria were contained in the material, sterilization was achieved by doses of 1.5 to 2 Mr. Applications of radiosterilization are discussed for the preparation of bacterial-cell vaccines, bacterial antigen complexes. chemical vaccines, and the preparation of vaccines made from bacteria killed by radiation. A study was made of the quality, antigenic and immunogenic properties, liability to retain Vi antigen, and toxicity of vaccines and antigenic complexes prepared from irradiated dysentery and typhoid bacteria. It was found that themore » radio-antigens were less toxic than antigens prepared from formalinized bacteria or from bacteria which had not been killed before the preparation of the antigen. When antigen previously prepared from formalinized bacteria was subjected to radiation, it either did not differ in toxic properties from the unirradiated antigen or was more toxic. Radiovaccines induced antibody formatdon in the same way as ordinary formalinized vaccines. Experimental data are tabulated. It was concluded that gamma irradiation can be used both for the production of intestinal group vaccines and antigens and for the sterilization of corresponding bacterial preparations already prepared. (C.H.)« less

ANTI-11[E]-PYROGLUTAMATE-MODIFIED AMYLOID β ANTIBODIES CROSS-REACT WITH OTHER PATHOLOGICAL Aβ SPECIES: RELEVANCE FOR IMMUNOTHERAPY

PubMed Central

Perez-Garmendia, Roxanna; Ibarra-Bracamontes, Vanessa; Vasilevko, Vitaly; Luna-Muñoz, Jose; Mena, Raul; Govezensky, Tzipe; Acero, Gonzalo; Manoutcharian, Karen; Cribbs, David H.; Gevorkian, Goar

2010-01-01

N-truncated/modified forms of amyloid beta (Aß) peptide are found in diffused and dense core plaques in Alzheimer's disease (AD) and Down's syndrome patients as well as animal models of AD, and represent highly desirable therapeutic targets. In the present study we have focused on Ntruncated/modified Aβ peptide bearing amino-terminal pyroglutamate at position 11 (AβN11(pE)). We identified two B-cell epitopes recognized by rabbit anti-AβN11(pE) polyclonal antibodies. Interestingly, rabbit anti-AβN11(pE) polyclonal antibodies bound also to full-length Aβ1-42 and N-truncated/modified AβN3(pE), suggesting that the three peptides may share a common B-cell epitope. Importantly, rabbit anti-AβN11(pE) antibodies bound to naturally occurring Aβ aggregates present in brain samples from AD patients. These results are potentially important for developing novel immunogens for targeting N-truncated/modified Aβ aggregates as well, since the most commonly used immunogens in the majority of vaccine studies have been shown to induce antibodies that recognize the N-terminal immunodominant epitope (EFRH) of the full length Aβ, which is absent in N-amino truncated peptides. PMID:20864186

Oral administration of live Shigella vaccine candidates in rhesus monkeys show no evidence of competition for colonization and immunogenicity between different serotypes.

PubMed

Ranallo, R T; Kaminski, R; Baqar, S; Dutta, M; Lugo-Roman, L A; Boren, T; Barnoy, S; Venkatesan, M M

2014-03-26

Live oral monovalent Shigella flexneri 2a vaccine candidates as well as bivalent formulations with Shigella sonnei were evaluated in a rhesus monkey model for colonization and immunogenicity. Freshly harvested suspensions of S. flexneri 2a vaccine candidates WRSf2G12 and WRSf2G15 as well as S. sonnei vaccine candidate WRSs3 were nasogastrically administered to groups of rhesus monkeys, Macaca mulatta, either in a monovalent form or when combined with each other. The animals were monitored daily for physical well-being, stools were subjected to quantitative colony immunoblot assays for bacterial excretion and blood and stools were evaluated for humoral and mucosal immune responses. No clinical symptoms were noted in any group of animals and the vaccine candidates were excreted robustly for 48-72h without significant changes in either the magnitude or duration of excretion when given as a monovalent or as bivalent mixtures. Similarly, immunological interferences were not apparent in the magnitude of humoral and mucosal immune responses observed toward Shigella-specific antigens when monkeys were fed monovalent or bivalent formulations. These results predict that a multivalent live oral vaccine of more than one serotype can have a favorable outcome for protection against shigellosis. Published by Elsevier Ltd.

Identification of a Short Cell-Penetrating Peptide from Bovine Lactoferricin for Intracellular Delivery of DNA in Human A549 Cells

PubMed Central

Liu, Betty R.; Huang, Yue-Wern; Aronstam, Robert S.; Lee, Han-Jung

2016-01-01

Cell-penetrating peptides (CPPs) have been shown to deliver cargos, including protein, DNA, RNA, and nanomaterials, in fully active forms into live cells. Most of the CPP sequences in use today are based on non-native proteins that may be immunogenic. Here we demonstrate that the L5a CPP (RRWQW) from bovine lactoferricin (LFcin), stably and noncovalently complexed with plasmid DNA and prepared at an optimal nitrogen/phosphate ratio of 12, is able to efficiently enter into human lung cancer A549 cells. The L5a CPP delivered a plasmid containing the enhanced green fluorescent protein (EGFP) coding sequence that was subsequently expressed in cells, as revealed by real-time PCR and fluorescent microscopy at the mRNA and protein levels, respectively. Treatment with calcium chloride increased the level of gene expression, without affecting CPP-mediated transfection efficiency. Zeta-potential analysis revealed that positively electrostatic interactions of CPP/DNA complexes correlated with CPP-mediated transport. The L5a and L5a/DNA complexes were not cytotoxic. This biomimetic LFcin L5a represents one of the shortest effective CPPs and could be a promising lead peptide with less immunogenic for DNA delivery in gene therapy. PMID:26942714

Identification of a Short Cell-Penetrating Peptide from Bovine Lactoferricin for Intracellular Delivery of DNA in Human A549 Cells.

PubMed

Liu, Betty R; Huang, Yue-Wern; Aronstam, Robert S; Lee, Han-Jung

2016-01-01

Cell-penetrating peptides (CPPs) have been shown to deliver cargos, including protein, DNA, RNA, and nanomaterials, in fully active forms into live cells. Most of the CPP sequences in use today are based on non-native proteins that may be immunogenic. Here we demonstrate that the L5a CPP (RRWQW) from bovine lactoferricin (LFcin), stably and noncovalently complexed with plasmid DNA and prepared at an optimal nitrogen/phosphate ratio of 12, is able to efficiently enter into human lung cancer A549 cells. The L5a CPP delivered a plasmid containing the enhanced green fluorescent protein (EGFP) coding sequence that was subsequently expressed in cells, as revealed by real-time PCR and fluorescent microscopy at the mRNA and protein levels, respectively. Treatment with calcium chloride increased the level of gene expression, without affecting CPP-mediated transfection efficiency. Zeta-potential analysis revealed that positively electrostatic interactions of CPP/DNA complexes correlated with CPP-mediated transport. The L5a and L5a/DNA complexes were not cytotoxic. This biomimetic LFcin L5a represents one of the shortest effective CPPs and could be a promising lead peptide with less immunogenic for DNA delivery in gene therapy.

Phenylalanine ammonia lyase, enzyme substitution therapy for phenylketonuria, where are we now?

PubMed

Sarkissian, Christineh N; Gámez, Alejandra

2005-12-01

Phenylketonuria (PKU) is an autosomal recessive genetic disorder in which mutations in the phenylalanine-4-hydroxylase (PAH) gene result in an inactive enzyme (PAH, EC 1.14.16.1). The effect is an inability to metabolize phenylalanine (Phe), translating into elevated levels of Phe in the bloodstream (hyperphenylalaninemia). If therapy is not implemented at birth, mental retardation can occur. PKU patients respond to treatment with a low-phenylalanine diet, but compliance with the diet is difficult, therefore the development of alternative treatments is desirable. Enzyme substitution therapy with a recombinant phenylalanine ammonia lyase (PAL) is currently being explored. This enzyme converts Phe to the harmless metabolites, trans-cinnamic acid and trace ammonia. Taken orally and when non-absorbable and protected, PAL lowers plasma Phe in mutant hyperphenylalaninemic mouse models. Subcutaneous administration of PAL results in more substantial lowering of plasma and significant reduction in brain Phe levels, however the metabolic effect is not sustained following repeated injections due to an immune response. We have chemically modified PAL by pegylation to produce a protected form of PAL that possesses better specific activity, prolonged half-life, and reduced immunogenicity in vivo. Subcutaneous administration of pegylated molecules to PKU mice has the desired metabolic response (prolonged reduction in blood Phe levels) with greatly attenuated immunogenicity.

Phase 1 Trials of rVSV Ebola Vaccine in Africa and Europe.

PubMed

Agnandji, Selidji T; Huttner, Angela; Zinser, Madeleine E; Njuguna, Patricia; Dahlke, Christine; Fernandes, José F; Yerly, Sabine; Dayer, Julie-Anne; Kraehling, Verena; Kasonta, Rahel; Adegnika, Akim A; Altfeld, Marcus; Auderset, Floriane; Bache, Emmanuel B; Biedenkopf, Nadine; Borregaard, Saskia; Brosnahan, Jessica S; Burrow, Rebekah; Combescure, Christophe; Desmeules, Jules; Eickmann, Markus; Fehling, Sarah K; Finckh, Axel; Goncalves, Ana Rita; Grobusch, Martin P; Hooper, Jay; Jambrecina, Alen; Kabwende, Anita L; Kaya, Gürkan; Kimani, Domtila; Lell, Bertrand; Lemaître, Barbara; Lohse, Ansgar W; Massinga-Loembe, Marguerite; Matthey, Alain; Mordmüller, Benjamin; Nolting, Anne; Ogwang, Caroline; Ramharter, Michael; Schmidt-Chanasit, Jonas; Schmiedel, Stefan; Silvera, Peter; Stahl, Felix R; Staines, Henry M; Strecker, Thomas; Stubbe, Hans C; Tsofa, Benjamin; Zaki, Sherif; Fast, Patricia; Moorthy, Vasee; Kaiser, Laurent; Krishna, Sanjeev; Becker, Stephan; Kieny, Marie-Paule; Bejon, Philip; Kremsner, Peter G; Addo, Marylyn M; Siegrist, Claire-Anne

2016-04-28

The replication-competent recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing a Zaire ebolavirus (ZEBOV) glycoprotein was selected for rapid safety and immunogenicity testing before its use in West Africa. We performed three open-label, dose-escalation phase 1 trials and one randomized, double-blind, controlled phase 1 trial to assess the safety, side-effect profile, and immunogenicity of rVSV-ZEBOV at various doses in 158 healthy adults in Europe and Africa. All participants were injected with doses of vaccine ranging from 300,000 to 50 million plaque-forming units (PFU) or placebo. No serious vaccine-related adverse events were reported. Mild-to-moderate early-onset reactogenicity was frequent but transient (median, 1 day). Fever was observed in up to 30% of vaccinees. Vaccine viremia was detected within 3 days in 123 of the 130 participants (95%) receiving 3 million PFU or more; rVSV was not detected in saliva or urine. In the second week after injection, arthritis affecting one to four joints developed in 11 of 51 participants (22%) in Geneva, with pain lasting a median of 8 days (interquartile range, 4 to 87); 2 self-limited cases occurred in 60 participants (3%) in Hamburg, Germany, and Kilifi, Kenya. The virus was identified in one synovial-fluid aspirate and in skin vesicles of 2 other vaccinees, showing peripheral viral replication in the second week after immunization. ZEBOV-glycoprotein-specific antibody responses were detected in all the participants, with similar glycoprotein-binding antibody titers but significantly higher neutralizing antibody titers at higher doses. Glycoprotein-binding antibody titers were sustained through 180 days in all participants. In these studies, rVSV-ZEBOV was reactogenic but immunogenic after a single dose and warrants further evaluation for safety and efficacy. (Funded by the Wellcome Trust and others; ClinicalTrials.gov numbers, NCT02283099, NCT02287480, and NCT02296983; Pan African Clinical Trials Registry number, PACTR201411000919191.).

Immunogenic Peptides (Vaccines) for the Treatment of Prostate and Breast Cancer | NCI Technology Transfer Center | TTC

Cancer.gov

Researchers at the NCI have developed a novel treatment for prostate and breast cancer using synthetic peptides derived from TARP, the T cell receptor gamma alternate reading frame protein. These immunogenic peptides from TARP elicit an immune response, triggering T cells to kill only the cancer cells within a patient.

Immunogenicity and efficacy of fowlpox-vectored and inactivated avian influenza vaccines alone or in a prime-boost schedule in chickens with maternal antibodies

USDA-ARS?s Scientific Manuscript database

Inactivated and fowlpox (FP)-vectored vaccines have been used to control avian influenza (AI) in poultry. In endemic countries, breeder flocks are vaccinated and therefore, maternally-derived antibodies (MDA) are transferred to their progeny. Results of several immunogenicity and efficacy studies ...

HIV-1 envelope glycoprotein

DOEpatents

Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

2017-08-22

The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

Identification and cloning of two immunogenic Clostridium perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO) of C. perfringens

USDA-ARS?s Scientific Manuscript database

Clostridium-related diseases such as gangrenous dermatitis (GD) and necrotic enteritis (NE) are increasingly emerging as major diseases in recent years with high economic loss around the world. In this report, we characterized two immunogenic Clostridium perfringens (CP) proteins (e.g., elongation f...

Stability of the Rabbit Immunogenic Marker of RA 27/3 Rubella Vaccine Virus After Human Passage

PubMed Central

Linnemann, Calvin C.; Hutchinson, Leslie; Rotte, Thomas C.; Hegg, Marion E.; Schiff, Gilbert M.

1974-01-01

Rabbits were inoculated intravenously with “wild” rubella virus, RA 27/3 rubella vaccine virus, or rubella virus isolated from recipients of RA 27/3 vaccine. Rabbits receiving “wild” virus developed rubella hemagglutination inhibition antibody, and those receiving vaccine virus did not. One of the five reisolates tested produced a low transient antibody response in two of the five rabbits inoculated with this strain. The study indicates that the rabbit immunogenic marker after intravenous injection can be used to determine if a rubella virus isolated from a patient is of “wild” or vaccine origin. There was no significant change in the reduced immunogenicity characteristics of the RA 27/3 vaccine virus after human passage. PMID:4206028

Vaccine adjuvants: Why and how.

PubMed

Christensen, Dennis

2016-10-02

Novel vaccine strategies include the so-called subunit vaccines, which encompass only the part of the pathogen to which immune recognition results in protection. The high purity of these vaccines make adverse events less likely, but it also makes the vaccines less immunogenic and therefore potentially less effective. Vaccine adjuvants that increase and modulate the immunogenicity of the vaccine are therefore added to solve this problem. Besides aluminum salts, which have been used in vaccines for 90 years, a number of novel vaccine adjuvants have been included in licensed vaccines over the last 30 years. Increasing insight into immunological mechanisms and how to manipulate them has replaced empirical with rational design of adjuvants, leading to vaccine adjuvants with increased and customized immunogenicity profiles without compromising vaccine safety.

Design and crystal structure of a native-like HIV-1 envelope trimer that engages multiple broadly neutralizing antibody precursors in vivo

DOE PAGES

Medina-Ramírez, Max; Garces, Fernando; Escolano, Amelia; ...

2017-08-28

Induction of broadly neutralizing antibodies (bNAbs) by HIV-1 envelope glycoprotein immunogens would be a major advance toward an effective vaccine. A critical step in this process is the activation of naive B cells expressing germline (gl) antibody precursors that have the potential to evolve into bNAbs. Here, we reengineered the BG505 SOSIP.664 glycoprotein to engage gl precursors of bNAbs that target either the trimer apex or the CD4-binding site. The resulting BG505 SOSIP.v4.1-GT1 trimer binds multiple bNAb gl precursors in vitro. Immunization experiments in knock-in mice expressing gl-VRC01 or gl-PGT121 show that this trimer activates B cells in vivo, resultingmore » in the secretion of specific antibodies into the sera. A crystal structure of the gl-targeting trimer at 3.2-Å resolution in complex with neutralizing antibodies 35O22 and 9H+109L reveals a native-like conformation and the successful incorporation of design features associated with binding of multiple gl-bNAb precursors.« less

Design and crystal structure of a native-like HIV-1 envelope trimer that engages multiple broadly neutralizing antibody precursors in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramírez, Max; Garces, Fernando; Escolano, Amelia

Induction of broadly neutralizing antibodies (bNAbs) by HIV-1 envelope glycoprotein immunogens would be a major advance toward an effective vaccine. A critical step in this process is the activation of naive B cells expressing germline (gl) antibody precursors that have the potential to evolve into bNAbs. Here, we reengineered the BG505 SOSIP.664 glycoprotein to engage gl precursors of bNAbs that target either the trimer apex or the CD4-binding site. The resulting BG505 SOSIP.v4.1-GT1 trimer binds multiple bNAb gl precursors in vitro. Immunization experiments in knock-in mice expressing gl-VRC01 or gl-PGT121 show that this trimer activates B cells in vivo, resultingmore » in the secretion of specific antibodies into the sera. A crystal structure of the gl-targeting trimer at 3.2-Å resolution in complex with neutralizing antibodies 35O22 and 9H+109L reveals a native-like conformation and the successful incorporation of design features associated with binding of multiple gl-bNAb precursors.« less

Clinical practice of analysis of anti-drug antibodies against interferon beta and natalizumab in multiple sclerosis patients in Europe: A descriptive study of test results

PubMed Central

Auer, Michael; Ryner, Malin; Hässler, Signe; Bachelet, Delphine; Mbogning, Cyprien; Warnke, Clemens; Buck, Dorothea; Hyldgaard Jensen, Poul Erik; Sievers, Claudia; Ingenhoven, Kathleen; Fissolo, Nicolas; Lindberg, Raija; Grummel, Verena; Donnellan, Naoimh; Comabella, Manuel; Montalban, Xavier; Kieseier, Bernd; Soelberg Sørensen, Per; Hartung, Hans-Peter; Derfuss, Tobias; Lawton, Andy; Sikkema, Dan; Pallardy, Marc; Hemmer, Bernhard; Deisenhammer, Florian; Broët, Philippe; Dönnes, Pierre; Davidson, Julie; Fogdell-Hahn, Anna

2017-01-01

Antibodies against biopharmaceuticals (anti-drug antibodies, ADA) have been a well-integrated part of the clinical care of multiple sclerosis (MS) in several European countries. ADA data generated in Europe during the more than 10 years of ADA monitoring in MS patients treated with interferon beta (IFNβ) and natalizumab have been pooled and characterized through collaboration within a European consortium. The aim of this study was to report on the clinical practice of ADA testing in Europe, considering the number of ADA tests performed and type of ADA assays used, and to determine the frequency of ADA testing against the different drug preparations in different countries. A common database platform (tranSMART) for querying, analyzing and storing retrospective data of MS cohorts was set up to harmonize the data and compare results of ADA tests between different countries. Retrospective data from six countries (Sweden, Austria, Spain, Switzerland, Germany and Denmark) on 20,695 patients and on 42,555 samples were loaded into tranSMART including data points of age, gender, treatment, samples, and ADA results. The previously observed immunogenic difference among the four IFNβ preparations was confirmed in this large dataset. Decreased usage of the more immunogenic preparations IFNβ-1a subcutaneous (s.c.) and IFNβ-1b s.c. in favor of the least immunogenic preparation IFNβ-1a intramuscular (i.m.) was observed. The median time from treatment start to first ADA test correlated with time to first positive test. Shorter times were observed for IFNβ-1b-Extavia s.c. (0.99 and 0.94 years) and natalizumab (0.25 and 0.23 years), which were introduced on the market when ADA testing was already available, as compared to IFNβ-1a i.m. (1.41 and 2.27 years), IFNβ-1b-Betaferon s.c. (2.51 and 1.96 years) and IFNβ-1a s.c. (2.11 and 2.09 years) which were available years before routine testing began. A higher rate of anti-IFNβ ADA was observed in test samples taken from older patients. Testing for ADA varies between different European countries and is highly dependent on the policy within each country. For drugs where routine monitoring of ADA is not in place, there is a risk that some patients remain on treatment for several years despite ADA positivity. For drugs where a strategy of ADA testing is introduced with the release of the drug, there is a reduced risk of having ADA positive patients and thus of less efficient treatment. This indicates that potential savings in health cost might be achieved by routine analysis of ADA. PMID:28170401

Clinical practice of analysis of anti-drug antibodies against interferon beta and natalizumab in multiple sclerosis patients in Europe: A descriptive study of test results.

PubMed

Link, Jenny; Ramanujam, Ryan; Auer, Michael; Ryner, Malin; Hässler, Signe; Bachelet, Delphine; Mbogning, Cyprien; Warnke, Clemens; Buck, Dorothea; Hyldgaard Jensen, Poul Erik; Sievers, Claudia; Ingenhoven, Kathleen; Fissolo, Nicolas; Lindberg, Raija; Grummel, Verena; Donnellan, Naoimh; Comabella, Manuel; Montalban, Xavier; Kieseier, Bernd; Soelberg Sørensen, Per; Hartung, Hans-Peter; Derfuss, Tobias; Lawton, Andy; Sikkema, Dan; Pallardy, Marc; Hemmer, Bernhard; Deisenhammer, Florian; Broët, Philippe; Dönnes, Pierre; Davidson, Julie; Fogdell-Hahn, Anna

2017-01-01

Antibodies against biopharmaceuticals (anti-drug antibodies, ADA) have been a well-integrated part of the clinical care of multiple sclerosis (MS) in several European countries. ADA data generated in Europe during the more than 10 years of ADA monitoring in MS patients treated with interferon beta (IFNβ) and natalizumab have been pooled and characterized through collaboration within a European consortium. The aim of this study was to report on the clinical practice of ADA testing in Europe, considering the number of ADA tests performed and type of ADA assays used, and to determine the frequency of ADA testing against the different drug preparations in different countries. A common database platform (tranSMART) for querying, analyzing and storing retrospective data of MS cohorts was set up to harmonize the data and compare results of ADA tests between different countries. Retrospective data from six countries (Sweden, Austria, Spain, Switzerland, Germany and Denmark) on 20,695 patients and on 42,555 samples were loaded into tranSMART including data points of age, gender, treatment, samples, and ADA results. The previously observed immunogenic difference among the four IFNβ preparations was confirmed in this large dataset. Decreased usage of the more immunogenic preparations IFNβ-1a subcutaneous (s.c.) and IFNβ-1b s.c. in favor of the least immunogenic preparation IFNβ-1a intramuscular (i.m.) was observed. The median time from treatment start to first ADA test correlated with time to first positive test. Shorter times were observed for IFNβ-1b-Extavia s.c. (0.99 and 0.94 years) and natalizumab (0.25 and 0.23 years), which were introduced on the market when ADA testing was already available, as compared to IFNβ-1a i.m. (1.41 and 2.27 years), IFNβ-1b-Betaferon s.c. (2.51 and 1.96 years) and IFNβ-1a s.c. (2.11 and 2.09 years) which were available years before routine testing began. A higher rate of anti-IFNβ ADA was observed in test samples taken from older patients. Testing for ADA varies between different European countries and is highly dependent on the policy within each country. For drugs where routine monitoring of ADA is not in place, there is a risk that some patients remain on treatment for several years despite ADA positivity. For drugs where a strategy of ADA testing is introduced with the release of the drug, there is a reduced risk of having ADA positive patients and thus of less efficient treatment. This indicates that potential savings in health cost might be achieved by routine analysis of ADA.

Fitness-Balanced Escape Determines Resolution of Dynamic Founder Virus Escape Processes in HIV-1 Infection

PubMed Central

Sunshine, Justine E.; Larsen, Brendan B.; Maust, Brandon; Casey, Ellie; Deng, Wenje; Chen, Lennie; Westfall, Dylan H.; Kim, Moon; Zhao, Hong; Ghorai, Suvankar; Lanxon-Cookson, Erinn; Rolland, Morgane; Collier, Ann C.; Maenza, Janine; Mullins, James I.

2015-01-01

ABSTRACT To understand the interplay between host cytotoxic T-lymphocyte (CTL) responses and the mechanisms by which HIV-1 evades them, we studied viral evolutionary patterns associated with host CTL responses in six linked transmission pairs. HIV-1 sequences corresponding to full-length p17 and p24 gag were generated by 454 pyrosequencing for all pairs near the time of transmission, and seroconverting partners were followed for a median of 847 days postinfection. T-cell responses were screened by gamma interferon/interleukin-2 (IFN-γ/IL-2) FluoroSpot using autologous peptide sets reflecting any Gag variant present in at least 5% of sequence reads in the individual's viral population. While we found little evidence for the occurrence of CTL reversions, CTL escape processes were found to be highly dynamic, with multiple epitope variants emerging simultaneously. We found a correlation between epitope entropy and the number of epitope variants per response (r = 0.43; P = 0.05). In cases in which multiple escape mutations developed within a targeted epitope, a variant with no fitness cost became fixed in the viral population. When multiple mutations within an epitope achieved fitness-balanced escape, these escape mutants were each maintained in the viral population. Additional mutations found to confer escape but undetected in viral populations incurred high fitness costs, suggesting that functional constraints limit the available sites tolerable to escape mutations. These results further our understanding of the impact of CTL escape and reversion from the founder virus in HIV infection and contribute to the identification of immunogenic Gag regions most vulnerable to a targeted T-cell attack. IMPORTANCE Rapid diversification of the viral population is a hallmark of HIV-1 infection, and understanding the selective forces driving the emergence of viral variants can provide critical insight into the interplay between host immune responses and viral evolution. We used deep sequencing to comprehensively follow viral evolution over time in six linked HIV transmission pairs. We then mapped T-cell responses to explore if mutations arose due to adaption to the host and found that escape processes were often highly dynamic, with multiple mutations arising within targeted epitopes. When we explored the impact of these mutations on replicative capacity, we found that dynamic escape processes only resolve with the selection of mutations that conferred escape with no fitness cost to the virus. These results provide further understanding of the complicated viral-host interactions that occur during early HIV-1 infection and may help inform the design of future vaccine immunogens. PMID:26223634

Immunization With Fc-Based Recombinant Epstein–Barr Virus gp350 Elicits Potent Neutralizing Humoral Immune Response in a BALB/c Mice Model

PubMed Central

Zhao, Bingchun; Zhang, Xiao; Krummenacher, Claude; Song, Shuo; Gao, Ling; Zhang, Haojiong; Xu, Miao; Feng, Lin; Feng, Qisheng; Zeng, Musheng; Xu, Yuting; Zeng, Yixin

2018-01-01

Epstein–Barr virus (EBV) was the first human virus proved to be closely associated with tumor development, such as lymphoma, nasopharyngeal carcinoma, and EBV-associated gastric carcinoma. Despite many efforts to develop prophylactic vaccines against EBV infection and diseases, no candidates have succeeded in effectively blocking EBV infection in clinical trials. Previous investigations showed that EBV gp350 plays a pivotal role in the infection of B-lymphocytes. Nevertheless, using monomeric gp350 proteins as antigens has not been effective in preventing infection. Multimeric forms of the antigen are more potently immunogenic than monomers; however, the multimerization elements used in previous constructs are not approved for human clinical trials. To prepare a much-needed EBV prophylactic vaccine that is potent, safe, and applicable, we constructed an Fc-based form of gp350 to serve as a dimeric antigen. Here, we show that the Fc-based gp350 antigen exhibits dramatically enhanced immunogenicity compared with wild-type gp350 protein. The complete or partial gp350 ectodomain was fused with the mouse IgG2a Fc domain. Fusion with the Fc domain did not impair gp350 folding, binding to a conformation-dependent neutralizing antibody (nAb) and binding to its receptor by enzyme-linked immunosorbent assay and surface plasmon resonance. Specific antibody titers against gp350 were notably enhanced by immunization with gp350-Fc dimers compared with gp350 monomers. Furthermore, immunization with gp350-Fc fusion proteins elicited potent nAbs against EBV. Our data strongly suggest that an EBV gp350 vaccine based on Fc fusion proteins may be an efficient candidate to prevent EBV infection in clinical applications. PMID:29765376

Biochemical, Conformational, and Immunogenic Analysis of Soluble Trimeric Forms of Henipavirus Fusion Glycoproteins

PubMed Central

Chan, Yee-Peng; Lu, Min; Dutta, Somnath; Yan, Lianying; Barr, Jennifer; Flora, Michael; Feng, Yan-Ru; Xu, Kai; Nikolov, Dimitar B.; Wang, Lin-Fa; Skiniotis, Georgios

2012-01-01

The henipaviruses, Hendra virus (HeV) and Nipah virus (NiV), are paramyxoviruses discovered in the mid- to late 1990s that possess a broad host tropism and are known to cause severe and often fatal disease in both humans and animals. HeV and NiV infect cells by a pH-independent membrane fusion mechanism facilitated by their attachment (G) and fusion (F) glycoproteins. Here, several soluble forms of henipavirus F (sF) were engineered and characterized. Recombinant sF was produced by deleting the transmembrane (TM) and cytoplasmic tail (CT) domains and appending a glycosylphosphatidylinositol (GPI) anchor signal sequence followed by GPI-phospholipase D digestion, appending a trimeric coiled-coil (GCNt) domain (sFGCNt), or deleting the TM, CT, and fusion peptide domain. These sF glycoproteins were produced as F0 precursors, and all were apparent stable trimers recognized by NiV-specific antisera. Surprisingly, however, only the GCNt-appended constructs (sFGCNt) could elicit cross-reactive henipavirus-neutralizing antibody in mice. In addition, sFGCNt constructs could be triggered in vitro by protease cleavage and heat to transition from an apparent prefusion to postfusion conformation, transitioning through an intermediate that could be captured by a peptide corresponding to the C-terminal heptad repeat domain of F. The pre- and postfusion structures of sFGCNt and non-GCNt-appended sF could be revealed by electron microscopy and were distinguishable by F-specific monoclonal antibodies. These data suggest that only certain sF constructs could serve as potential subunit vaccine immunogens against henipaviruses and also establish important tools for further structural, functional, and diagnostic studies on these important emerging viruses. PMID:22915804

The Recombinant Bacille Calmette-Guérin Vaccine VPM1002: Ready for Clinical Efficacy Testing.

PubMed

Nieuwenhuizen, Natalie E; Kulkarni, Prasad S; Shaligram, Umesh; Cotton, Mark F; Rentsch, Cyrill A; Eisele, Bernd; Grode, Leander; Kaufmann, Stefan H E

2017-01-01

The only licensed vaccine against tuberculosis (TB), bacille Calmette-Guérin (BCG), protects against severe extrapulmonary forms of TB but is virtually ineffective against the most prevalent form of the disease, pulmonary TB. BCG was genetically modified at the Max Planck Institute for Infection Biology to improve its immunogenicity by replacing the urease C encoding gene with the listeriolysin encoding gene from Listeria monocytogenes . Listeriolysin perturbates the phagosomal membrane at acidic pH. Urease C is involved in neutralization of the phagosome harboring BCG. Its depletion allows for rapid phagosome acidification and promotes phagolysosome fusion. As a result, BCGΔ ureC :: hly (VPM1002) promotes apoptosis and autophagy and facilitates release of mycobacterial antigens into the cytosol. In preclinical studies, VPM1002 has been far more efficacious and safer than BCG. The vaccine was licensed to Vakzine Projekt Management and later sublicensed to the Serum Institute of India Pvt. Ltd., the largest vaccine producer in the world. The vaccine has passed phase I clinical trials in Germany and South Africa, demonstrating its safety and immunogenicity in young adults. It was also successfully tested in a phase IIa randomized clinical trial in healthy South African newborns and is currently undergoing a phase IIb study in HIV exposed and unexposed newborns. A phase II/III clinical trial will commence in India in 2017 to assess efficacy against recurrence of TB. The target indications for VPM1002 are newborn immunization to prevent TB as well as post-exposure immunization in adults to prevent TB recurrence. In addition, a Phase I trial in non-muscle invasive bladder cancer patients has been completed, and phase II trials are ongoing. This review describes the development of VPM1002 from the drawing board to its clinical assessment.

Novel polyvalent live vaccine against varicella-zoster and mumps virus infections.

PubMed

Matsuura, Masaaki; Somboonthum, Pranee; Murakami, Kouki; Ota, Megumi; Shoji, Masaki; Kawabata, Kenji; Mizuguchi, Hiroyuki; Gomi, Yasuyuki; Yamanishi, Koichi; Mori, Yasuko

2013-10-01

The varicella-zoster virus (VZV) Oka vaccine strain (vOka) is a highly immunogenic and safe live vaccine that has long been used worldwide. Because its genome is large, making it suitable for inserting foreign genes, vOka is considered a candidate vector for novel polyvalent vaccines. Previously, a recombinant vOka, rvOka-HN, that expresses mumps virus (MuV) hemagglutinin-neuraminidase (HN) was generated by the present team. rvOka-HN induces production of neutralizing antibodies against MuV in guinea pigs. MuV also expresses fusion (F) protein, which is important for inducing neutralizing antibodies, in its viral envelope. To induce a more robust immune response against MuV than that obtained with rvOka-HN, here an rvOka expressing both HN and F (rvOka-HN-F) was generated. However, co-expression of HN and F caused the infected cells to form syncytia, which reduced virus titers. To reduce the amount of cell fusion, an rvOka expressing HN and a mutant F, F(S195Y) were generated. Almost no syncytia formed among the rvOka-HN-F(S195Y)-infected cells and the growth of rvOka-HN-F(S195Y) was similar to that of the original vOka clone. Moreover, replacement of serine 195 with tyrosine had no effect on the immunogenicity of F in mice and guinea pigs. Although obvious augmentation of neutralizing antibody production was not observed after adding F protein to vOka-HN, the anti-F antibodies did have neutralizing activity. These data suggest that F protein contributes to induction of immune protection against MuV. Therefore this recombinant virus is a promising candidate vaccine for polyvalent protection against both VZV and MuV. © 2013 The Societies and Wiley Publishing Asia Pty Ltd.

Safety and immunogenicity of mammalian cell derived and Modified Vaccinia Ankara vectored African swine fever subunit antigens in swine.

PubMed

Lopera-Madrid, Jaime; Osorio, Jorge E; He, Yongqun; Xiang, Zuoshuang; Adams, L Garry; Laughlin, Richard C; Mwangi, Waithaka; Subramanya, Sandesh; Neilan, John; Brake, David; Burrage, Thomas G; Brown, William Clay; Clavijo, Alfonso; Bounpheng, Mangkey A

2017-03-01

A reverse vaccinology system, Vaxign, was used to identify and select a subset of five African Swine Fever (ASF) antigens that were successfully purified from human embryonic kidney 293 (HEK) cells and produced in Modified vaccinia virus Ankara (MVA) viral vectors. Three HEK-purified antigens [B646L (p72), E183L (p54), and O61R (p12)], and three MVA-vectored antigens [B646L, EP153R, and EP402R (CD2v)] were evaluated using a prime-boost immunization regimen swine safety and immunogenicity study. Antibody responses were detected in pigs following prime-boost immunization four weeks apart with the HEK-293-purified p72, p54, and p12 antigens. Notably, sera from the vaccinees were positive by immunofluorescence on ASFV (Georgia 2007/1)-infected primary macrophages. Although MVA-vectored p72, CD2v, and EP153R failed to induce antibody responses, interferon-gamma (IFN-γ + ) spot forming cell responses against all three antigens were detected one week post-boost. The highest IFN-γ + spot forming cell responses were detected against p72 in pigs primed with MVA-p72 and boosted with the recombinant p72. Antigen-specific (p12, p72, CD2v, and EP153R) T-cell proliferative responses were also detected post-boost. Collectively, these results are the first demonstration that ASFV subunit antigens purified from mammalian cells or expressed in MVA vectors are safe and can induce ASFV-specific antibody and T-cell responses following a prime-boost immunization regimen in swine. Copyright © 2017 Elsevier B.V. All rights reserved.

Covalent decoration of adenovirus vector capsids with the carbohydrate epitope αGal does not improve vector immunogenicity, but allows to study the in vivo fate of adenovirus immunocomplexes.

PubMed

Kratzer, Ramona F; Espenlaub, Sigrid; Hoffmeister, Andrea; Kron, Matthias W; Kreppel, Florian

2017-01-01

Adenovirus-based vectors are promising tools for genetic vaccination. However, several obstacles have to be overcome prior to a routine clinical application of adenovirus-based vectors as efficacious vectored vaccines. The linear trisaccharide epitope αGal (alpha-Gal) with the carbohydrate sequence galactose-α-1,3-galactosyl-β-1,4-N-acetylglucosamine has been described as a potent adjuvant for recombinant or attenuated vaccines. Humans and α-1,3-galactosyltransferase knockout mice do not express this epitope. Upon exposure of α-1,3-galactosyltransferase-deficient organisms to αGal in the environment, large amounts of circulating anti-Gal antibodies are produced consistently. Immunocomplexes formed between recombinant αGal-decorated vaccines and anti-Gal antibodies exhibit superior immunogenicity. We studied the effects of the trisaccharide epitope on CD8 T cell responses that are directed specifically to vector-encoded transgenic antigens. For that, covalently αGal-decorated adenovirus vectors were delivered to anti-Gal α-1,3-galactosyltransferase knockout mice. We generated replication-defective, E1-deleted adenovirus type 5 vectors that were decorated with αGal at the hexon hypervariable regions 1 or 5, at fiber knob, or at penton base. Surprisingly, none of the adenovirus immunocomplexes being formed from αGal-decorated adenovirus vectors and anti-Gal immunoglobulins improved the frequencies of CD8 T cell responses against the transgenic antigen ovalbumin. Humoral immunity directed to the adenovirus vector was neither increased. However, our data indicated that decoration of Ad vectors with the αGal epitope is a powerful tool to analyze the fate of adenovirus immunocomplexes in vivo.

Synthesis, Biodegradability, and Biocompatibility of Lysine Diisocyanate–Glucose Polymers

PubMed Central

ZHANG, JIAN-YING; BECKMAN, ERIC J.; HU, JING; YANG, GUO-GUANG; AGARWAL, SUDHA; HOLLINGER, JEFFREY O.

2016-01-01

The success of a tissue-engineering application depends on the use of suitable biomaterials that degrade in a timely manner and induce the least immunogenicity in the host. With this purpose in mind, we have attempted to synthesize a novel nontoxic biodegradable lysine diisocyanate (LDI)-and glucose-based polymer via polymerization of highly purified LDI with glucose and its subsequent hydration to form a spongy matrix. The LDI–glucose polymer was degradable in aqueous solutions at 37, 22, and 4°C, and yielded lysine and glucose as breakdown products. The degradation products of the LDI–glucose polymer did not significantly affect the pH of the solution. The physical properties of the polymer were found to be adequate for supporting cell growth in vitro, as evidenced by the fact that rabbit bone marrow stromal cells (BMSCs) attached to the polymer matrix, remained viable on its surface, and formed multilayered confluent cultures with retention of their phenotype over a period of 2 to 4 weeks. These observations suggest that the LDI–glucose polymer and its degradation products were nontoxic in vitro. Further examination in vivo over 8 weeks revealed that subcutaneous implantation of hydrated matrix degraded in vivo three times faster than in vitro. The implanted polymer was not immunogenic and did not induce antibody responses in the host. Histological analysis of the implanted polymer showed that LDI–glucose polymer induced a minimal foreign body reaction, with formation of a capsule around the degrading polymer. The results suggest that biodegradable peptide-based polymers can be synthesized, and may potentially find their way into biomedical applications because of their biodegradability and biocompatibility. PMID:12459056

Antibodies Elicited by Multiple Envelope Glycoprotein Immunogens in Primates Neutralize Primary Human Immunodeficiency Viruses (HIV-1) Sensitized by CD4-Mimetic Compounds

PubMed Central

Madani, Navid; Princiotto, Amy M.; Easterhoff, David; Bradley, Todd; Luo, Kan; Williams, Wilton B.; Liao, Hua-Xin; Moody, M. Anthony; Phad, Ganesh E.; Vázquez Bernat, Néstor; Melillo, Bruno; Santra, Sampa; Smith, Amos B.; Karlsson Hedestam, Gunilla B.; Haynes, Barton

2016-01-01

ABSTRACT The human immunodeficiency virus (HIV-1) envelope glycoproteins (Env) mediate virus entry through a series of complex conformational changes triggered by binding to the receptors CD4 and CCR5/CXCR4. Broadly neutralizing antibodies that recognize conserved Env epitopes are thought to be an important component of a protective immune response. However, to date, HIV-1 Env immunogens that elicit broadly neutralizing antibodies have not been identified, creating hurdles for vaccine development. Small-molecule CD4-mimetic compounds engage the CD4-binding pocket on the gp120 exterior Env and induce Env conformations that are highly sensitive to neutralization by antibodies, including antibodies directed against the conserved Env region that interacts with CCR5/CXCR4. Here, we show that CD4-mimetic compounds sensitize primary HIV-1 to neutralization by antibodies that can be elicited in monkeys and humans within 6 months by several Env vaccine candidates, including gp120 monomers. Monoclonal antibodies directed against the gp120 V2 and V3 variable regions were isolated from the immunized monkeys and humans; these monoclonal antibodies neutralized a primary HIV-1 only when the virus was sensitized by a CD4-mimetic compound. Thus, in addition to their direct antiviral effect, CD4-mimetic compounds dramatically enhance the HIV-1-neutralizing activity of antibodies that can be elicited with currently available immunogens. Used as components of microbicides, the CD4-mimetic compounds might increase the protective efficacy of HIV-1 vaccines. IMPORTANCE Preventing HIV-1 transmission is a high priority for global health. Eliciting antibodies that can neutralize transmitted strains of HIV-1 is difficult, creating problems for the development of an effective vaccine. We found that small-molecule CD4-mimetic compounds sensitize HIV-1 to antibodies that can be elicited in vaccinated humans and monkeys. These results suggest an approach to prevent HIV-1 sexual transmission in which a virus-sensitizing microbicide is combined with a vaccine. PMID:26962221

Vaccination of HIV-infected pregnant women: implications for protection of their young infants.

PubMed

Dangor, Ziyaad; Nunes, Marta C; Kwatra, Gaurav; Lala, Sanjay G; Madhi, Shabir A

2017-01-01

The prevention of mother to child transmission of HIV has resulted in reduced burden of pediatric HIV-infection, but the prevalence of maternal HIV infection remains high in sub-Saharan African countries. HIV-exposed-uninfected infants have an increased risk of morbidity and mortality due to infectious diseases than HIV-unexposed infants, particularly during the first six months of life, which in part might be due to lower levels of pathogen-specific protective antibodies acquired transplacentally from their mothers. This could be mitigated by vaccinating pregnant women to boost antibody levels; although vaccine responses among HIV-infected pregnant women might differ compared to HIV-uninfected women. We reviewed studies that compared natural and vaccine-induced antibody levels to different epitopes between HIV-infected and HIV-uninfected pregnant women. Most studies reported lower baseline/pre-vaccination antibody levels in HIV-infected pregnant women, which may not be reversed by antiretroviral therapy during pregnancy. There were only few studies on vaccination of HIV-infected pregnant women, mainly on influenza virus and group B Streptococcus (GBS) vaccines. Immunogenicity studies on influenza vaccines indicated that HIV-infected pregnant women had lower vaccine induced hemagglutination inhibition antibody titers and a decreased likelihood of seroconversion compared to HIV-uninfected women; and while higher CD4+ T-lymphocyte levels were associated with better immune responses to vaccination, HIV viral load was not associated with responses. Furthermore, infants born to influenza vaccinated HIV-infected pregnant women also had lower antibody levels and a lower proportion of HIV-exposed infants had titers above the putative correlate of protection compared to HIV-unexposed infants. The immunogenicity of a CRM 197 -conjugated trivalent GBS vaccine was also lower in HIV-infected pregnant women compared to HIV-uninfected women, irrespective of CD4+ T-lymphocyte counts. Poorer immunogenicity of vaccines reported in HIV-infected compared to HIV-uninfected pregnant women might compromise the potential benefits to their young infants. Alternate vaccination strategies, including vaccines with higher antigen concentration, adjuvanted vaccines or multiple doses schedules might be required in HIV-infected pregnant women to optimize antibody transferred to their fetuses.

Safety and immunogenicity of different doses and schedules of a live attenuated tetravalent dengue vaccine (TDV) in healthy adults: A Phase 1b randomized study.

PubMed

Rupp, Richard; Luckasen, Gary Joseph; Kirstein, Judith Lee; Osorio, Jorge E; Santangelo, Joseph D; Raanan, Marsha; Smith, Mary Kathryn; Wallace, Derek; Gordon, Gilad S; Stinchcomb, Dan T

2015-11-17

A safe, effective dengue vaccine that can simultaneously induce immunity to all four dengue virus serotypes (DENV-1-4) is a public health priority. A chimeric tetravalent dengue vaccine (TDV) based on an attenuated DENV-2 serotype backbone was evaluated in healthy, flavivirus-seronegative adults. In this randomized, multicenter, Phase 1b study conducted in the United States, the safety and immunogenicity of TDV were evaluated in 140 participants aged 18-45 years in six dosing regimen study groups. Participants were injected subcutaneously on Days 0 and 90; placebo (saline) was injected where appropriate to maintain double blinding. Three different TDV dosages (TDV, a vaccine in which TDV-4 had been increased three-fold, and a one-tenth TDV dose), and single or double dosing were evaluated in one and/or both arms. Primary endpoints were solicited and unsolicited adverse events (AEs) and seroconversion rates to DENV-1-4 at Day 120. The severity of all AEs was generally mild. The most common unsolicited AEs were headache (52%), fatigue (43%) and myalgia (29%). The incidence of injection site pain ranged from 29 to 64% and 5 to 52% among study groups after the first and second doses, respectively. At Day 120, the ranges of seroconversion rates among the groups were DEN-1: 84-100%; DEN-2: 96-100%; DEN-3: 83-100%; and DEN-4: 33-77%. More than 80% of participants in each group seroconverted to at least three dengue serotypes. Substantial GMT increases from baseline were observed for DEN-1-3 at all time points from Day 30 onward; DEN-4 GMT increases were lower. Increasing TDV-4 slightly increased DEN-4 GMT, did not impact DEN-2 and DEN-3 GMT, but reduced DEN-1 GMT. Neither multiple dosing in both arms, nor one-tenth TDV dosing meaningfully impacted GMT increases relative to TDV. All TDV doses and dosing schedules were well tolerated and immunogenic in healthy flavivirus-naive adults (ClinicalTrials.gov NCT01511250). Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vectorology and Factor Delivery in Induced Pluripotent Stem Cell Reprogramming

PubMed Central

2014-01-01

Induced pluripotent stem cell (iPSC) reprogramming requires sustained expression of multiple reprogramming factors for a limited period of time (10–30 days). Conventional iPSC reprogramming was achieved using lentiviral or simple retroviral vectors. Retroviral reprogramming has flaws of insertional mutagenesis, uncontrolled silencing, residual expression and re-activation of transgenes, and immunogenicity. To overcome these issues, various technologies were explored, including adenoviral vectors, protein transduction, RNA transfection, minicircle DNA, excisable PiggyBac (PB) transposon, Cre-lox excision system, negative-sense RNA replicon, positive-sense RNA replicon, Epstein-Barr virus-based episomal plasmids, and repeated transfections of plasmids. This review provides summaries of the main vectorologies and factor delivery systems used in current reprogramming protocols. PMID:24625220

Deep sequencing methods for protein engineering and design.

PubMed

Wrenbeck, Emily E; Faber, Matthew S; Whitehead, Timothy A

2017-08-01

The advent of next-generation sequencing (NGS) has revolutionized protein science, and the development of complementary methods enabling NGS-driven protein engineering have followed. In general, these experiments address the functional consequences of thousands of protein variants in a massively parallel manner using genotype-phenotype linked high-throughput functional screens followed by DNA counting via deep sequencing. We highlight the use of information rich datasets to engineer protein molecular recognition. Examples include the creation of multiple dual-affinity Fabs targeting structurally dissimilar epitopes and engineering of a broad germline-targeted anti-HIV-1 immunogen. Additionally, we highlight the generation of enzyme fitness landscapes for conducting fundamental studies of protein behavior and evolution. We conclude with discussion of technological advances. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quality, immunogenicity and stability of meningococcal serogroup ACWY-CRM197, DT and TT glycoconjugate vaccines.

PubMed

Beresford, Nicola J; Martino, Angela; Feavers, Ian M; Corbel, Michael J; Bai, Xilian; Borrow, Ray; Bolgiano, Barbara

2017-06-16

A physicochemical and immunological study of the stability of three different meningococcal (Men) ACWY conjugate vaccines was performed to evaluate any patterns of serogroup oligo- or polysaccharide-specific or carrier protein-specific stability that would affect immunogenicity. Critical quality and stability-indicating characteristics were measured, with the study supporting the suitability of both HPLC-SEC and HPAEC-PAD methods to detect changes following inappropriate vaccine storage. All three final products, ACWY-CRM 197 , -DT and -TT conjugate vaccines had expected quality indicator values and similar immunogenicity in a mouse model (anti-PS IgG and rSBA) when stored at +2-8°C. When stored at ≥+37°C, all conjugated carrier proteins and serogroup saccharides were affected. Direct correlations were observed between the depolymerization of the MenA saccharide as evidenced by a size-reduction in the MenA conjugates (CRM 197 , DT and TT) and their immunogenicity. MenA was the most labile serogroup, followed by MenC; then MenW and Y, which were similar. At high temperatures, the conjugated carrier proteins were prone to unfolding and/or aggregation. The anti-MenC IgG responses of the multivalent conjugate vaccines in mice were equivalent to those observed in monovalent MenC conjugate vaccines, and were independent of the carrier protein. For any newly developing MenACWY saccharide-protein conjugate vaccines, a key recommendation would be to consider the lyophilization of final product to prevent deleterious degradation that would affect immunogenicity. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Lot-to-lot consistency study of the fully liquid pentavalent DTwP-HepB-Hib vaccine Quinvaxem® demonstrating clinical equivalence, suitability of the vaccine as a booster and concomitant administration with measles vaccine

PubMed Central

Aspinall, Sanet; Traynor, Deirdre; Bedford, Philip; Hartmann, Katharina

2012-01-01

This double-blind, randomized study evaluated the immunogenicity and safety of three production lots of the fully liquid combination DTwP-Hep-Hib vaccine, Quinvaxem® (Crucell, The Netherlands) in 360 healthy infants aged 42–64 d old given at 6, 10 and 14 weeks of age (Core Study). The Core Study was followed by an open-label Booster Phase evaluating immunogenicity and safety of a booster dose of Quinvaxem® given with either concomitant or deferred measles vaccine in 227 infants who completed the Core Study. One month after the third dose of Quinvaxem® immune responses reflecting seroprotection or seroconversion were observed in more than 90% of infants for all three vaccine lots. Quinvaxem® elicited a strong booster response as demonstrated by a large increase in antibodies against all antigens, which appeared to be unaffected by concomitant administration of the measles vaccine. Safety results were in line with previous reports for Quinvaxem® with no unexpected adverse events (AEs) being reported. In the Core Study and Booster Phase, Quinvaxem® was well tolerated. No study vaccine-related serious AEs were reported. Thus, Quinvaxem® was immunogenic and well-tolerated when administered to infants according to a 6–10–14 week vaccination schedule. The three production lots had consistent reactogenicity and immunogenicity profiles. The booster dose of Quinvaxem® was also immunogenic and safe, regardless of whether a monovalent measles vaccine was administered concomitantly or one month later. PMID:22854660

Immunogenicity of biologics in inflammatory bowel disease

PubMed Central

Vermeire, Séverine; Gils, Ann; Accossato, Paola; Lula, Sadiq; Marren, Amy

2018-01-01

Crohn’s disease and ulcerative colitis are chronic inflammatory disorders of the gastrointestinal tract. Treatment options include biologic therapies; however, a proportion of patients lose response to biologics, partly due to the formation of anti-drug antibodies (ADAbs). Concomitant immunosuppressive agents reduce the development of ADAbs. This review article aims to assess the immunogenicity of biologic therapies and their clinical implications. A comprehensive literature search was conducted for articles published January 2009 to August 2015 reporting immunogenicity to adalimumab (ADM), certolizumab pegol (CZP), golimumab, infliximab (IFX), ustekinumab, and vedolizumab in inflammatory bowel disease (IBD). Eligible articles were reviewed and quality assessed by independent reviewers. Overall, 122 publications reporting 114 studies were assessed. ADAbs were reported for all agents, but the percentage of patients developing ADAbs was extremely variable, with the highest (65.3%) being for IFX administration to patients with IBD. ADAb presence was frequently associated with a reduction in primary efficacy and a loss of response, and, for IFX, an increase in adverse events (AEs). Lower serum levels of ADM, CZP and IFX were seen in ADAbs-positive rather than ADAbs-negative patients; pharmacokinetic data were unavailable for other therapies. Little information was available regarding the timing of ADAb development; studies reported their detection from as early as 10–14 days up to months after treatment initiation. Biologic therapies carry an intrinsic risk of immunogenicity, although reported rates of ADAbs vary considerably. The clinical implications of immunogenicity are a concern for effective treatment; further research, particularly into the more recently approved biologics, is required. PMID:29383030

The Optimisation of the Expression of Recombinant Surface Immunogenic Protein of Group B Streptococcus in Escherichia coli by Response Surface Methodology Improves Humoral Immunity.

PubMed

Díaz-Dinamarca, Diego A; Jerias, José I; Soto, Daniel A; Soto, Jorge A; Díaz, Natalia V; Leyton, Yessica Y; Villegas, Rodrigo A; Kalergis, Alexis M; Vásquez, Abel E

2018-03-01

Group B Streptococcus (GBS) is the leading cause of neonatal meningitis and a common pathogen in livestock and aquaculture industries around the world. Conjugate polysaccharide and protein-based vaccines are under development. The surface immunogenic protein (SIP) is a conserved protein in all GBS serotypes and has been shown to be a good target for vaccine development. The expression of recombinant proteins in Escherichia coli cells has been shown to be useful in the development of vaccines, and the protein purification is a factor affecting their immunogenicity. The response surface methodology (RSM) and Box-Behnken design can optimise the performance in the expression of recombinant proteins. However, the biological effect in mice immunised with an immunogenic protein that is optimised by RSM and purified by low-affinity chromatography is unknown. In this study, we used RSM for the optimisation of the expression of the rSIP, and we evaluated the SIP-specific humoral response and the property to decrease the GBS colonisation in the vaginal tract in female mice. It was observed by NI-NTA chromatography that the RSM increases the yield in the expression of rSIP, generating a better purification process. This improvement in rSIP purification suggests a better induction of IgG anti-SIP immune response and a positive effect in the decreased GBS intravaginal colonisation. The RSM applied to optimise the expression of recombinant proteins with immunogenic capacity is an interesting alternative in the evaluation of vaccines in preclinical phase, which could improve their immune response.

Predicted MHC peptide binding promiscuity explains MHC class I 'hotspots' of antigen presentation defined by mass spectrometry eluted ligand data.

PubMed

Jappe, Emma Christine; Kringelum, Jens; Trolle, Thomas; Nielsen, Morten

2018-02-15

Peptides that bind to and are presented by MHC class I and class II molecules collectively make up the immunopeptidome. In the context of vaccine development, an understanding of the immunopeptidome is essential, and much effort has been dedicated to its accurate and cost-effective identification. Current state-of-the-art methods mainly comprise in silico tools for predicting MHC binding, which is strongly correlated with peptide immunogenicity. However, only a small proportion of the peptides that bind to MHC molecules are, in fact, immunogenic, and substantial work has been dedicated to uncovering additional determinants of peptide immunogenicity. In this context, and in light of recent advancements in mass spectrometry (MS), the existence of immunological hotspots has been given new life, inciting the hypothesis that hotspots are associated with MHC class I peptide immunogenicity. We here introduce a precise terminology for defining these hotspots and carry out a systematic analysis of MS and in silico predicted hotspots. We find that hotspots defined from MS data are largely captured by peptide binding predictions, enabling their replication in silico. This leads us to conclude that hotspots, to a great degree, are simply a result of promiscuous HLA binding, which disproves the hypothesis that the identification of hotspots provides novel information in the context of immunogenic peptide prediction. Furthermore, our analyses demonstrate that the signal of ligand processing, although present in the MS data, has very low predictive power to discriminate between MS and in silico defined hotspots. © 2018 John Wiley & Sons Ltd.

Safety and immunogenicity of one versus two doses of Takeda's tetravalent dengue vaccine in children in Asia and Latin America: interim results from a phase 2, randomised, placebo-controlled study.

PubMed

Sáez-Llorens, Xavier; Tricou, Vianney; Yu, Delia; Rivera, Luis; Tuboi, Suely; Garbes, Pedro; Borkowski, Astrid; Wallace, Derek

2017-06-01

Dengue is the most common mosquito-borne viral disease in human beings, and vector control has not halted its spread worldwide. A dengue vaccine for individuals aged 9 years and older has been licensed, but there remains urgent medical need for a vaccine that is safe and effective against all four dengue virus serotypes (DENV-1-4) in recipients of all ages. Here, we present the preplanned interim analyses at 6 months of a tetravalent dengue vaccine candidate (TDV), which is comprised of an attenuated DENV-2 virus strain (TDV-2) and three chimeric viruses containing the premembrane and envelope protein genes of DENV-1, DENV-3, and DENV-4 genetically engineered into the attenuated TDV-2 genome backbone (TDV-1, TDV-3, and TDV-4). An ongoing phase 2, randomised, double-blind, placebo-controlled trial of a TDV is being done at three sites in dengue-endemic countries (Dominican Republic, Panama, and the Philippines) to determine its safety and immunogenicity over 48 months in healthy participants aged 2-17 years who were randomly assigned (1:2:5:1) using an interactive web response system (stratified by age) to subcutaneous TDV injection (one 0·5 mL dose containing 2·5 × 10 4 plaque-forming units [PFU] of TDV-1; 6·3 × 10 3 PFU of TDV-2; 3·2 × 10 4 PFU of TDV-3; and 4·0 × 10 5 PFU of TDV-4) in different dose schedules (two-dose regimen at 0 and 3 months, one dose at 0 months, or one dose at 0 months and a booster at 12 months) or placebo. The primary endpoint of this 6 month interim analysis was geometric mean titres (GMTs) of neutralising antibodies against DENV-1-4 in the per-protocol immunogenicity subset at 1 month, 3 months, and 6 months after the first injection. Safety was assessed as a secondary outcome as percentage of participants with serious adverse events in all participants who were injected (safety set), and solicited and unsolicited adverse events (immunogenicity subset). This trial is registered with ClinicalTrials.gov, number NCT02302066. 1800 participants were enrolled between Dec 5, 2014, and Feb 13, 2015. 1794 participants were given study injection as follows: 200 participants were given two-dose regimen at 0 and 3 months (group 1), 398 were given one dose at 0 months (group 2), 998 were given one dose at 0 months and will be given (trial ongoing) a booster at 12 months (group 3), and 198 were given placebo (group 4). These 1794 participants were included in the safety set; 562 participants were randomly assigned to the immunogenicity subset, of which 503 were included in the per-protocol set. TDV elicited neutralising antibodies against all DENV serotypes, which peaked at 1 month and remained elevated above baseline at 6 months. At 6 months, GMTs of neutralising antibodies against DENV-1 were 489 (95% CI 321-746) for group 1, 434 (306-615) for group 2, 532 (384-738) for group 3, and 62 (32-120) for group 4; GMTs of neutralising antibodies against DENV-2 were 1565 (1145-2140) for group 1, 1639 (1286-2088) for group 2, 1288 (1031-1610) for group 3, and 86 (44-169) for group 4; GMTs of neutralising antibodies against DENV-3 were 160 (104-248) for group 1, 151 (106-214) for group 2, 173 (124-240) for group 3, and 40 (23-71) for group 4; and GMTs of neutralising antibodies against DENV-4 were 117 (79-175) for group 1, 110 (80-149) for group 2, 93 (69-125) for group 3, and 24 (15-38) for group 4. No vaccine-related serious adverse events occurred; 15 (3%) of 562 participants in the immunogenicity subset reported vaccine-related unsolicited adverse events. The reactogenicity profile of TDV was acceptable, and similar to previous findings with TDV. TDV is safe and immunogenic in individuals aged 2-17 years, irrespective of previous dengue exposure. A second TDV dose induced enhanced immunogenicity against DENV-3 and DENV-4 in children who were seronegative before vaccination. These data supported the initiation of phase 3 evaluation of the efficacy and safety of TDV given in a two-dose schedule 3 months apart, with analyses that take into account baseline age and dengue serostatus. Takeda Vaccines. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Regulatory Evaluation of Vaccines for Human Use.

PubMed

Baylor, Norman W

2016-01-01

A vaccine is an immunogen, the administration of which is intended to stimulate the immune system to result in the prevention, amelioration, or therapy of any disease or infection (US Food and Drug Administration. Guidance for Industry: content and format of chemistry, manufacturing, and controls information and establishment description information for a vaccine or related product). A vaccine may be a live attenuated preparation of microorganisms, inactivated (killed) whole organisms, living irradiated cells, crude fractions, or purified immunogens, including those derived from recombinant DNA in a host cell, conjugates formed by covalent linkage of components, synthetic antigens, polynucleotides (such as the plasmid DNA vaccines), living vectored cells expressing specific heterologous immunogens, or cells pulsed with immunogen. Vaccines are highly complex products that differ from small molecule drugs because of the biological nature of the source materials such as those derived from microorganisms as well as the various cell substrates from which some are derived. Regardless of the technology used, because of their complexities, vaccines must undergo extensive characterization and testing. Special expertise and procedures are needed for their manufacture, control, and regulation. The Food and Drug Administration (FDA) is the National Regulatory Authority (NRA) in the United States responsible for assuring quality, safety, and effectiveness of all human medical products, including vaccines for human use.The Center for Biologics Evaluation and Research (CBER) within the US FDA is responsible for overseeing the regulation of therapeutic and preventative vaccines against infectious diseases. Authority for the regulation of vaccines resides in Section 351 of the Public Health Service Act and specific sections of the Federal Food, Drug, and Cosmetic Act (FD&C). Vaccines are regulated as biologics and licensed based on the demonstration of safety and effectiveness. The vaccine development process can be divided into two major categories: those events that are not under the regulatory authority of the FDA and are exploratory in nature and those events that are subject to regulatory authority by the FDA. Exploratory events or research and development cover basic research drug discovery processes that occur before the sponsor submits an investigational new drug application (IND) to the FDA. There are four main stages of vaccine development under the purview of regulatory authorities: preclinical, clinical (IND), licensing, and post-licensure. Throughout their life cycle from preclinical evaluation to post-licensure lot release testing, vaccines are subject to rigorous testing and oversight by manufacturers and NRAs. In this chapter an overview of the regulatory evaluation and testing requirements for vaccines is presented.

Bioterrorism Preparedness for Infectious Disease (BTPID) Proposal

DTIC Science & Technology

2007-01-01

approximately $210,000/ year x 5 years. (Pending) Safety, Tolerability and Immunogenicity of ACAM3000 Modified Vaccinia Ankara (MVA) Small Pox ...Hospital. • (Pending) Safety, Tolerability and Immunogenicity of ACAM3000 Modified Vaccinia Ankara (MVA) Small Pox Vaccine in HIV-Seropositive...choosing optimal pox virus derived vectors as vaccines in terms of reducing clinical reactogenicity and inducing dendritic cell (DC) aturation. 2006 Elsevier

77 FR 8263 - Prospective Grant of Exclusive License: The Development of Anti-mesothelin Targeted Immunotoxins...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

... ``Pseudomonas Exotoxin A with Less Immunogenic B Cell Epitopes'' [HHS Ref. E-263-2011/0-US-01], US Patent application 61/495,085 entitled ``Pseudomonas Exotoxin A with Less Immunogenic T Cell Epitopes'' [HHS Ref. E... Immunotoxin in Which All B-Cell Epitopes Have Been Removed and Which Has High Cytotoxic Activity'' [HHS Ref. E...

Canarypox virus expressing infectious bursal disease VP2 protein as immunogen for chickens

PubMed Central

Zanetti, Flavia Adriana; Grand, María Daniela Conte; Mitarotonda, Romina Cristina; Taboga, Oscar Alberto; Calamante, Gabriela

2014-01-01

Canarypox viruses (CNPV) carrying the coding sequence of VP2 protein from infectious bursal disease virus (IBDV) were obtained. These viruses were able to express VP2 protein in vitro and to induce IBDV-neutralizing antibodies when inoculated in specific pathogen-free chickens demonstrating that CNPV platform is usefulness to develop immunogens for chickens. PMID:24948937

[Safety and immunogenicity of a 7-valent pneumococcal conjugate vaccine (Prevenar) booster dose in healthy Chinese toddlers].

PubMed

Li, Rong-cheng; Li, Feng-xiang; Li, Yan-ping

2009-06-01

To evaluate the safety and immunogenicity of the booster dose of 7 valent pneumococcal conjugate vaccine (PCV7) to the healthy Chinese toddlers who had received 3 primary doses. Four hundred and eighty-eight Chinese toddlers received a booster dose of PCV7 at age of 12-15 months following a primary series of the vaccine given at ages 3, 4, 5 months separately with Diphtheria Tetanus Acellular Pertussis Combined Vaccine (DTaP) in Group 1 or concurrently with DTaP in Group 2. Following the booster dose immunization, each subject was followed up for 30 days to observe the safety of the vaccine. Blood samples were taken from a subset of subjects prior and post 30 days the booster dose immunization to evaluate immunogenicity. A high proportion of subjects in Group 1 (89%) and Group 2 (91%) remained afebrile after the booster dose. Local reactions to the PCV7 booster dose were generally mild. For each serotype, the rise in GMC (post-/pre-vaccination) showed a statistically significant difference (P<0.0001) between both groups. PCV7 administered as a booster dose is generally safe, well tolerate, and immunogenic in healthy Chinese toddlers.

Assessing the relationship between antigenicity and immunogenicity of human rabies vaccines when administered by intradermal route

PubMed Central

Bilagumba, Gangaboraiah; Ravish, Haradanahalli Shankarappa; Narayana, Hanumanthappa Ashwath Doddabele

2010-01-01

The metadata of 10 published studies and 3 vaccine trial reports comprising of 19 vaccine cohorts from four countries conducted over a period of 23 years (1986–2009) was used for metaanalysis. The vaccines studied were purified chick embryo cell vaccine (Rabipur, India and Germany), purified vero cell rabies vaccine (Verorab, France; Indirab, India) and human diploid cell vaccine (MIRV, France). The potency of these vaccines varied from 0.55 IU to 2.32 IU per intradermal dose of 0.1 ml per site. The vaccines were administered to 1,011 subjects comprising of 19 cohorts and using five different ID regimens. The immunogenicity was measured by assays of rabies virus neutralizing antibody (RVNA) titres using rapid fluorescent focus inhibition test (RFFIT) [15 cohorts] and mouse neutralization test (MNT) [4 cohorts]. The statistical analysis of the data was done by Karl Pearson's correlation coefficient to measure the relationship between antigenicity and immunogenicity. It was revealed that, there was no significant linear relationship between antigenicity and immunogenicity of rabies vaccines when administered by intradermal route (p > 0.230 and p > 0.568). PMID:20523131

Structural and Computational Biology in the Design of Immunogenic Vaccine Antigens

PubMed Central

Liljeroos, Lassi; Malito, Enrico; Ferlenghi, Ilaria; Bottomley, Matthew James

2015-01-01

Vaccination is historically one of the most important medical interventions for the prevention of infectious disease. Previously, vaccines were typically made of rather crude mixtures of inactivated or attenuated causative agents. However, over the last 10–20 years, several important technological and computational advances have enabled major progress in the discovery and design of potently immunogenic recombinant protein vaccine antigens. Here we discuss three key breakthrough approaches that have potentiated structural and computational vaccine design. Firstly, genomic sciences gave birth to the field of reverse vaccinology, which has enabled the rapid computational identification of potential vaccine antigens. Secondly, major advances in structural biology, experimental epitope mapping, and computational epitope prediction have yielded molecular insights into the immunogenic determinants defining protective antigens, enabling their rational optimization. Thirdly, and most recently, computational approaches have been used to convert this wealth of structural and immunological information into the design of improved vaccine antigens. This review aims to illustrate the growing power of combining sequencing, structural and computational approaches, and we discuss how this may drive the design of novel immunogens suitable for future vaccines urgently needed to increase the global prevention of infectious disease. PMID:26526043

The Immunogenicity and Safety of CYD-Tetravalent Dengue Vaccine (CYD-TDV) in Children and Adolescents: A Systematic Review.

PubMed

Agarwal, Raksheeth; Wahid, Mardiastuti H; Yausep, Oliver E; Angel, Sharon H; Lokeswara, Angga W

2017-01-01

to assess the immunogenicity and safety of CYD-tetravalent dengue vaccine (CYD-TDV) in children. comprehensive literature searches were conducted on various databases. Randomized-controlled trials on children with CYD-TDV as intervention were selected based on inclusion and exclusion criteria. Data extracted from selected trials included safety of vaccine and immunogenicity in terms of Geometric Mean Titres (GMT) of antibodies.   six clinical trials were selected based on preset criteria. GMT values were obtained using 50% Plaque Reduction Neutralization Test (PRNT) and safety was semi-quantitatively assessed based on adverse effects. Additional data processing was done to obtain a better understanding on the trends among the studies. The results showed that the groups vaccinated with CYD-TDV showed higher immunogenicity against dengue virus antigens than the control groups. Safety results were satisfactory in all trials, and most severe side effects were unrelated to the vaccine. CYD-TDV is both effective and safe for patients in endemic regions. This gives promise for further development and large-scale research on this vaccine to assess its efficacy in decreasing dengue prevalence, and its pervasive implementation in endemic countries, such as Indonesia.

Structural and Computational Biology in the Design of Immunogenic Vaccine Antigens.

PubMed

Liljeroos, Lassi; Malito, Enrico; Ferlenghi, Ilaria; Bottomley, Matthew James

2015-01-01

Vaccination is historically one of the most important medical interventions for the prevention of infectious disease. Previously, vaccines were typically made of rather crude mixtures of inactivated or attenuated causative agents. However, over the last 10-20 years, several important technological and computational advances have enabled major progress in the discovery and design of potently immunogenic recombinant protein vaccine antigens. Here we discuss three key breakthrough approaches that have potentiated structural and computational vaccine design. Firstly, genomic sciences gave birth to the field of reverse vaccinology, which has enabled the rapid computational identification of potential vaccine antigens. Secondly, major advances in structural biology, experimental epitope mapping, and computational epitope prediction have yielded molecular insights into the immunogenic determinants defining protective antigens, enabling their rational optimization. Thirdly, and most recently, computational approaches have been used to convert this wealth of structural and immunological information into the design of improved vaccine antigens. This review aims to illustrate the growing power of combining sequencing, structural and computational approaches, and we discuss how this may drive the design of novel immunogens suitable for future vaccines urgently needed to increase the global prevention of infectious disease.

Phage display as a promising approach for vaccine development.

PubMed

Aghebati-Maleki, Leili; Bakhshinejad, Babak; Baradaran, Behzad; Motallebnezhad, Morteza; Aghebati-Maleki, Ali; Nickho, Hamid; Yousefi, Mehdi; Majidi, Jafar

2016-09-29

Bacteriophages are specific antagonists to bacterial hosts. These viral entities have attracted growing interest as optimal vaccine delivery vehicles. Phages are well-matched for vaccine design due to being highly stable under harsh environmental conditions, simple and inexpensive large scale production, and potent adjuvant capacities. Phage vaccines have efficient immunostimulatory effects and present a high safety profile because these viruses have made a constant relationship with the mammalian body during a long-standing evolutionary period. The birth of phage display technology has been a turning point in the development of phage-based vaccines. Phage display vaccines are made by expressing multiple copies of an antigen on the surface of immunogenic phage particles, thereby eliciting a powerful and effective immune response. Also, the ability to produce combinatorial peptide libraries with a highly diverse pool of randomized ligands has transformed phage display into a straightforward, versatile and high throughput screening methodology for the identification of potential vaccine candidates against different diseases in particular microbial infections. These libraries can be conveniently screened through an affinity selection-based strategy called biopanning against a wide variety of targets for the selection of mimotopes with high antigenicity and immunogenicity. Also, they can be panned against the antiserum of convalescent individuals to recognize novel peptidomimetics of pathogen-related epitopes. Phage display has represented enormous promise for finding new strategies of vaccine discovery and production and current breakthroughs promise a brilliant future for the development of different phage-based vaccine platforms.

Disabled infectious single cycle-herpes simplex virus (DISC-HSV) as a vector for immunogene therapy of cancer.

PubMed

Rees, Robert C; McArdle, Stephanie; Mian, Shahid; Li, Geng; Ahmad, Murrium; Parkinson, Richard; Ali, Selman A

2002-02-01

Disabled infectious single cycle-herpes simplex viruses (DISC-HSV) have been shown to be safe for use in humans and may be considered efficacious as vectors for immunogene therapy in cancer. Preclinical studies show that DISC-HSV is an efficient delivery system for cytokine genes and antigens. DISC-HSV infects a high proportion of cells, resulting in rapid gene expression for at least 72 h. The DISC-HSV-mGM-CSF vector, when inoculated into tumors, induces tumor regression in a high percentage of animals, concomitant with establishing a cytotoxic T-cell response, which is MHC class I restricted and directed against peptides of known tumor antigens. The inherent properties of DISC-HSV makes it a suitable vector for consideration in human immunogene therapy trials.

Bioengineering towards self-assembly of particulate vaccines.

PubMed

Rehm, Bernd H A

2017-12-01

There is an unmet demand for safe and efficient vaccines for prevention of various infectious diseases. Subunit vaccines comprise selected pathogen specific antigens are a safe alternative to whole organism vaccines. However they often lack immunogenicity. Natural and synthetic self-assembling polymers and proteins will be reviewed in view their use to encapsulate and/or display antigens to serve as immunogenic antigen carriers for induction of protective immunity. Recent advances made in in vivo assembly of antigen-displaying polyester inclusions will be a focus. Particulate vaccines are inherently immunogenic due to enhanced uptake by antigen presenting cells which process antigens mediating adaptive immune responses. Bioengineering approaches enable the design of tailor-made particulate vaccines to fine tune immune responses towards protective immunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coupling of aggregation and immunogenicity in biotherapeutics: T- and B-cell immune epitopes may contain aggregation-prone regions.

PubMed

Kumar, Sandeep; Singh, Satish K; Wang, Xiaoling; Rup, Bonita; Gill, Davinder

2011-05-01

Biotherapeutics, including recombinant or plasma-derived human proteins and antibody-based molecules, have emerged as an important class of pharmaceuticals. Aggregation and immunogenicity are among the major bottlenecks during discovery and development of biotherapeutics. Computational tools that can predict aggregation prone regions as well as T- and B-cell immune epitopes from protein sequence and structure have become available recently. Here, we describe a potential coupling between aggregation and immunogenicity: T-cell and B-cell immune epitopes in therapeutic proteins may contain aggregation-prone regions. The details of biological mechanisms behind this observation remain to be understood. However, our observation opens up an exciting potential for rational design of de-immunized novel, as well as follow on biotherapeutics with reduced aggregation propensity.

[Novel therapy for malignant lymphoma: adoptive immuno-gene therapy using chimeric antigen receptor(CAR)-expressing T lymphocytes].

PubMed

Ozawa, Keiya

2014-03-01

Adoptive T-cell therapy using chimeric antigen receptor (CAR) technology is a novel approach to cancer immuno-gene therapy. CARs are hybrid proteins consisting of target-antigen-specific single-chain antibody fragment fused to intracellular T-cell activation domains (CD28 or CD137/CD3 zeta receptor). CAR-expressing engineered T lymphocytes can directly recognize and kill tumor cells in an HLA independent manner. In the United States, promising results have been obtained in the clinical trials of adoptive immuno-gene therapy using CD19-CAR-T lymphocytes for the treatment of refractory B-cell malignancies, including chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL). In this review article, CD19-CAR-T gene therapy for refractory B-cell non-Hodgkin lymphoma is discussed.

Effect of the Deletion of Genes Encoding Proteins of the Extracellular Virion Form of Vaccinia Virus on Vaccine Immunogenicity and Protective Effectiveness in the Mouse Model

PubMed Central

Meseda, Clement A.; Campbell, Joseph; Kumar, Arunima; Garcia, Alonzo D.; Merchlinsky, Michael; Weir, Jerry P.

2013-01-01

Antibodies to both infectious forms of vaccinia virus, the mature virion (MV) and the enveloped virion (EV), as well as cell-mediated immune response appear to be important for protection against smallpox. EV virus particles, although more labile and less numerous than MV, are important for dissemination and spread of virus in infected hosts and thus important in virus pathogenesis. The importance of the EV A33 and B5 proteins for vaccine induced immunity and protection in a murine intranasal challenge model was evaluated by deletion of both the A33R and B5R genes in a vaccine-derived strain of vaccinia virus. Deletion of either A33R or B5R resulted in viruses with a small plaque phenotype and reduced virus yields, as reported previously, whereas deletion of both EV protein-encoding genes resulted in a virus that formed small infection foci that were detectable and quantifiable only by immunostaining and an even more dramatic decrease in total virus yield in cell culture. Deletion of B5R, either as a single gene knockout or in the double EV gene knockout virus, resulted in a loss of EV neutralizing activity, but all EV gene knockout viruses still induced a robust neutralizing activity against the vaccinia MV form of the virus. The effect of elimination of A33 and/or B5 on the protection afforded by vaccination was evaluated by intranasal challenge with a lethal dose of either vaccinia virus WR or IHD-J, a strain of vaccinia virus that produces relatively higher amounts of EV virus. The results from multiple experiments, using a range of vaccination doses and virus challenge doses, and using mortality, morbidity, and virus dissemination as endpoints, indicate that the absence of A33 and B5 have little effect on the ability of a vaccinia vaccine virus to provide protection against a lethal intranasal challenge in a mouse model. PMID:23785523

Idiotypic specificities and cross-reactivities of rabbit antibodies to human antidextran.

PubMed Central

Outschoorn, I M

1979-01-01

Idiotypic antibodies were prepared by immunizing two groups of rabbits with dextran-antidextran specific precipitates and purified antidextran obtained subsequently from the same human donor. Half of the animals were made tolerant to pooled human IgG. Tests showed that sera from tolerant rabbits reacted better with the antidextran preparation used to immunize the other group of animals than with the antidextran that formed part of their immunogen. Non-tolerant animals did not recognize this serological difference. Sera from animals immunized with the antidextran preparation donated later reacted better with this material irrespective of their tolerance to human IgG. PMID:92456

Neutrophils come of age in chronic inflammation

PubMed Central

Caielli, Simone; Banchereau, Jacques; Pascual, Virginia

2013-01-01

Neutrophils have long been known to participate in acute inflammation, but a role in chronic inflammatory and autoimmune diseases is now emerging. These cells are key players in the recognition and elimination of pathogens, but they also sense self components, including nucleic acids and products of sterile tissue damage. While this normally contributes to tissue repair, it can also lead to the release of highly immunogenic products that can trigger and/or amplify autoimmune pathogenic loops. Understanding the mechanisms that underlie neutrophil activation, migration, survival and their various forms of death in health and disease might provide us with new approaches to treat chronic inflammatory conditions. PMID:23127555

Induction of Immunogenic Cell Death with Non-Thermal Plasma for Cancer Immunotherapy

NASA Astrophysics Data System (ADS)

Lin, Abraham G.

Even with the recent advancements in cancer immunotherapy, treatments are still associated with debilitating side effects and unacceptable fail rates. Induction of immunogenic cell death (ICD) in tumors is a promising approach to cancer treatment that may overcome these deficiencies. Cells undergoing ICD pathways enhance the interactions between cancerous cells and immune cells of the patient, resulting in the generation of anti-cancer immunity. The goal of this therapy relies on the engagement and reestablishment of the patient's natural immune processes to target and eliminate cancerous cells systemically. The main objective of this research was to determine if non-thermal plasma could be used to elicit immunogenic cancer cell death for cancer immunotherapy. My hypothesis was that plasma induces immunogenic cancer cell death through oxidative stress pathways, followed by development of a specific anti-tumor immune response. This was tested by investigating the interactions between plasma and multiple cancerous cells in vitro and validating anti-tumor immune responses in vivo. Following plasma treatment, two surrogate ICD markers, secreted adenosine triphosphate (ATP) and surface exposed calreticulin (ecto-CRT), were emitted from all three cancerous cell lines tested: A549 lung carcinoma cell line, CNE-1 radiation-resistant nasopharyngeal cell line and CT26 colorectal cancer cell line. When these cells were co-cultured with macrophages, cells of the innate immune system, the tumoricidal activity of macrophages was enhanced, thus demonstrating the immunostimulatory activity of cells undergoing ICD. The underlying mechanisms of plasma-induced ICD were also evaluated. When plasma is generated, four major components are produced: electromagnetic fields, ultraviolet radiation, and charged and neutral reactive species. Of these, we determined that plasma-generated charged and short-lived reactive oxygen species (ROS) were the major effectors of ICD. Following plasma treatment, ROS immediately increased. When chemical attenuators of ROS were used, intracellular ROS was abrogated and emission of ICD markers were attenuated. This strongly suggests that plasma-induced ICD is associated with increased intracellular ROS. The gold-standard approach to evaluating whether a stimulus can elicit genuine ICD relies on a vaccination assay. CT26 colorectal cancer cells were treated at ICD-inducing regimes of plasma and injected into syngeneic Balb/c mice. One week later, mice were challenged with live CT26 cancer cells. Tumor progression was moderated in animals immunized with plasma-treated CT26 cells. Altogether, these provide strong evidence that plasma regimes can be adapted for a new application: ICD induction. Next, a study was conducted to test the potential of plasma to induce ICD in tumors in animals. Plasma treatment of subcutaneous tumors in mice elicited the emission of ecto-CRT and high mobility group box 1 (HMGB1), another marker of ICD, in the tumor and also recruited CD11c+ and CD45+ immune cells locally. This was followed by development of cancer-specific splenic T cells, indicating that a systemic anti-tumor response was elicited from localized plasma treatment of the tumor. Overall, this work demonstrates the development of non-thermal plasma as a novel method of inducing immunogenic cell death for cancer immunotherapy. The obtained results further our understanding of plasma-cellular interaction mechanisms and highlight the potential for clinical translation.

Structures of Coxsackievirus A16 Capsids with Native Antigenicity: Implications for Particle Expansion, Receptor Binding, and Immunogenicity.

PubMed

Ren, Jingshan; Wang, Xiangxi; Zhu, Ling; Hu, Zhongyu; Gao, Qiang; Yang, Pan; Li, Xuemei; Wang, Junzhi; Shen, Xinliang; Fry, Elizabeth E; Rao, Zihe; Stuart, David I

2015-10-01

Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the primary causes of the epidemics of hand-foot-and-mouth disease (HFMD) that affect more than a million children in China each year and lead to hundreds of deaths. Although there has been progress with vaccines for EV71, the development of a CVA16 vaccine has proved more challenging, and the EV71 vaccine does not give useful cross-protection, despite the capsid proteins of the two viruses sharing about 80% sequence identity. The structural details of the expanded forms of the capsids, which possess nonnative antigenicity, are now well understood, but high resolution information for the native antigenic form of CVA16 has been missing. Here, we remedy this with high resolution X-ray structures of both mature and natural empty CVA16 particles and also of empty recombinant viruslike particles of CVA16 produced in insect cells, a potential vaccine antigen. All three structures are unexpanded native particles and antigenically identical. The recombinant particles have recruited a lipid moiety to stabilize the native antigenic state that is different from the one used in a natural virus infection. As expected, the mature CVA16 virus is similar to EV71; however, structural and immunogenic comparisons highlight differences that may have implications for vaccine production. Hand-foot-and-mouth disease is a serious public health threat to children in Asian-Pacific countries, resulting in millions of cases. EV71 and CVA16 are the two dominant causative agents of the disease that, while usually mild, can cause severe neurological complications, leading to hundreds of deaths. EV71 vaccines do not provide protection against CVA16. A CVA16 vaccine or bivalent EV71/CVA16 vaccine is therefore urgently needed. We report atomic structures for the mature CVA16 virus, a natural empty particle, and a recombinant CVA16 virus-like particle that does not contain the viral genome. All three particles have similar structures and identical antigenicity. The recombinant particles, produced in insect cells (a system suitable for making vaccine antigen), are stabilized by recruiting from the insect cells a small molecule that is different from that used by the virus in a normal infection. We present structural and immunogenic comparisons with EV71 to facilitate structure-based drug design and vaccine development. Copyright © 2015, Ren et al.

A Chimeric HIV-1 gp120 Fused with Vaccinia Virus 14K (A27) Protein as an HIV Immunogen

PubMed Central

Vijayan, Aneesh; García-Arriaza, Juan; C. Raman, Suresh; Conesa, José Javier; Chichón, Francisco Javier; Santiago, César; Sorzano, Carlos Óscar S.; Carrascosa, José L.; Esteban, Mariano

2015-01-01

In the HIV vaccine field, there is a need to produce highly immunogenic forms of the Env protein with the capacity to trigger broad B and T-cell responses. Here, we report the generation and characterization of a chimeric HIV-1 gp120 protein (termed gp120-14K) by fusing gp120 from clade B with the vaccinia virus (VACV) 14K oligomeric protein (derived from A27L gene). Stable CHO cell lines expressing HIV-1 gp120-14K protein were generated and the protein purified was characterized by size exclusion chromatography, electron microscopy and binding to anti-Env antibodies. These approaches indicate that gp120-14K protein is oligomeric and reacts with a wide spectrum of HIV-1 neutralizing antibodies. Furthermore, in human monocyte-derived dendritic cells (moDCs), gp120-14K protein upregulates the levels of several proinflammatory cytokines and chemokines associated with Th1 innate immune responses (IL-1β, IFN-γ, IL-6, IL-8, IL-12, RANTES). Moreover, we showed in a murine model, that a heterologous prime/boost immunization protocol consisting of a DNA prime with a plasmid expressing gp120-14K protein followed by a boost with MVA-B [a recombinant modified vaccinia virus Ankara (MVA) expressing HIV-1 gp120, Gag, Pol and Nef antigens from clade B], generates stronger, more polyfunctional, and greater effector memory HIV-1-specific CD4+ and CD8+ T-cell immune responses, than immunization with DNA-gp120/MVA-B. The DNA/MVA protocol was superior to immunization with the combination of protein/MVA and the latter was superior to a prime/boost of MVA/MVA or protein/protein. In addition, these immunization protocols enhanced antibody responses against gp120 of the class IgG2a and IgG3, together favoring a Th1 humoral immune response. These results demonstrate that fusing HIV-1 gp120 with VACV 14K forms an oligomeric protein which is highly antigenic as it activates a Th1 innate immune response in human moDCs, and in vaccinated mice triggers polyfunctional HIV-1-specific adaptive and memory T-cell immune responses, as well as humoral responses. This novel HIV-1 gp120-14K immunogen might be considered as an HIV vaccine candidate for broad T and B-cell immune responses. PMID:26208356

Multivalent Immunogenic Vaccines for Treating Prostate and Breast Cancer | NCI Technology Transfer Center | TTC

Cancer.gov

Researchers at the NCI have developed a treatment for prostate and breast cancer using multivalent peptides derived from TARP, the T cell receptor gamma alternate reading frame protein. These immunogenic peptides from TARP elicit an immune response, triggering T cells to kill only the cancer cells within a patient. NCI seeks licensees or co-development partners to commercialize this invention.

Trypanosoma cruzi. Surface antigens of blood and culture forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nogueira, N.; Chaplan, S.; Tydings, J.D.

1981-03-01

The surface polypeptides of both cultured and blood forms of Trypanosoma cruzi were iodinated by the glucose oxidase-lactoperoxidase technique. Blood-form trypomastigotes (BFT) isolated form infected mice displayed a major 90,000-Mr component. In contrast, both epimastigotes and trypomastigotes obtained form acellular cultures expressed a smaller 75,000-Mr peptide. Both major surface components were presumably glycoproteins in terms of their binding to concanavalin A-Sepharose 4B. Within a 3-h period, both blood and culture forms synthesized their respective surface glycoproteins (90,000 Mr and 75,000 Mr, respectively in vitro. (/sub 35/S)methionine-labeled surface peptides were immunoprecipitated with immune sera of both human and murine origin. Amore » panel of sera form patients with chronic Chagas' disease and hyperimmunized mice recognized similar surface peptides. These immunogens were the same components as the major iodinated species. The major BFT surface peptide was readily removed by trypsin treatment of the parasites, although the procedure did not affect the 75,000-Mr peptide from the culture forms. Two-dimensional polyacrylamide gel electrophoresis revealed that the 90,000-Mr peptide found on BFT was an acidic protein of isoelectric point (pI) 5.0, whereas, the 75,000-Mr peptide form culture-form trypomastigotes has a pI of 7.2. The 90,000-Mr component is thought to be responsible for the anti-phagocytic properties of the BFT (1).« less

Structure-Based Design of a Soluble Prefusion-Closed HIV-1 Env Trimer with Reduced CD4 Affinity and Improved Immunogenicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chuang, Gwo-Yu; Geng, Hui; Pancera, Marie

ABSTRACT The HIV-1 envelope (Env) trimer is a target for vaccine design as well as a conformational machine that facilitates virus entry by transitioning between prefusion-closed, CD4-bound, and coreceptor-bound conformations by transitioning into a postfusion state. Vaccine designers have sought to restrict the conformation of the HIV-1 Env trimer to its prefusion-closed state as this state is recognized by most broadly neutralizing, but not nonneutralizing, antibodies. We previously identified a disulfide bond, I201C-A433C (DS), which stabilizes Env in the vaccine-desired prefusion-closed state. When placed into the context of BG505 SOSIP.664, a soluble Env trimer mimic developed by Sanders, Moore, andmore » colleagues, the engineered DS-SOSIP trimer showed reduced conformational triggering by CD4. Here, we further stabilize DS-SOSIP through a combination of structure-based design and 96-well-based expression and antigenic assessment. From 103 designs, we identified one, named DS-SOSIP.4mut, with four additional mutations at the interface of potentially mobile domains of the prefusion-closed structure. We also determined the crystal structures of DS-SOSIP.4mut at 4.1-Å resolution and of an additional DS-SOSIP.6mut variant at 4.3-Å resolution, and these confirmed the formation of engineered disulfide bonds. Notably, DS-SOSIP.4mut elicited a higher ratio of tier 2 autologous titers versus tier 1 V3-sensitive titers than BG505 SOSIP.664. DS-SOSIP.4mut also showed reduced recognition of CD4 and increased thermostability. The improved antigenicity, thermostability, and immunogenicity of DS-SOSIP.4mut suggest utility as an immunogen or a serologic probe; moreover, the specific four alterations identified here, M154, M300, M302, and L320 (4mut), can also be transferred to other HIV-1 Env trimers of interest to improve their properties. IMPORTANCEOne approach to elicit broadly neutralizing antibodies against HIV-1 is to stabilize the structurally flexible HIV-1 envelope (Env) trimer in a conformation that displays predominantly broadly neutralizing epitopes and few to no nonneutralizing epitopes. The prefusion-closed conformation of HIV-1 Env has been identified as one such preferred conformation, and a current leading vaccine candidate is the BG505 DS-SOSIP variant, comprising two disulfides and an Ile-to-Pro mutation of Env from strain BG505. Here, we introduced additional mutations to further stabilize BG505 DS-SOSIP in the vaccine-preferred prefusion-closed conformation. In guinea pigs, our best mutant, DS-SOSIP.4mut, elicited a significantly higher ratio of autologous versus V3-directed neutralizing antibody responses than the SOSIP-stabilized form. We also observed an improvement in thermostability and a reduction in CD4 affinity. With improved antigenicity, stability, and immunogenicity, DS-SOSIP.4mut-stabilized trimers may have utility as HIV-1 immunogens or in other antigen-specific contexts, such as with B-cell probes.« less

Fine Mapping of Murine Antibody Responses to Immunization with a Novel Soluble Form of Hepatitis C Virus Envelope Glycoprotein Complex

PubMed Central

Ruwona, Tinashe B.; Giang, Erick; Nieusma, Travis

2014-01-01

ABSTRACT The hepatitis C virus (HCV) envelope glycoprotein E1E2 complex is a candidate vaccine antigen. Previous immunization studies of E1E2 have yielded various results on its ability to induce virus-neutralizing antibodies in animal models and humans. The murine model has become a vital tool for HCV research owing to the development of humanized mice susceptible to HCV infection. In this study, we investigated the antibody responses of mice immunized with E1E2 and a novel soluble form of E1E2 (sE1E2) by a DNA prime and protein boost strategy. The results showed that sE1E2 elicited higher antibody titers and a greater breadth of reactivity than the wild-type cell-associated E1E2. However, immune sera elicited by either immunogen were only weakly neutralizing. In order to understand the contrasting results of binding and serum neutralizing activities, epitopes targeted by the polyclonal antibody responses were mapped and monoclonal antibodies (MAbs) were generated. The results showed that the majority of serum antibodies were directed to the E1 region 211 to 250 and the E2 regions 421 to 469, 512 to 539, 568 to 609, and 638 to 651, instead of the well-known immunodominant E2 hypervariable region 1 (HVR1). Unexpectedly, in MAb analysis, ∼12% of MAbs isolated were specific to the conserved E2 antigenic site 412 to 423, and 85% of them cross-neutralized multiple HCV isolates. The epitopes recognized by these MAbs are similar but distinct from the previously reported HCV1 and AP33 broadly neutralizing epitopes. In conclusion, E1E2 can prime B cells specific to conserved neutralizing epitopes, but the levels of serum neutralizing antibodies elicited are insufficient for effective virus neutralization. The sE1E2 constructs described in this study can be a useful template for rational antigen engineering. IMPORTANCE Hepatitis C virus infects 2 to 3% of the world's population and is a leading cause of liver failures and the need for liver transplantation. The virus envelope glycoprotein complex E1E2 produced by detergent extraction of cells overexpressing the protein was evaluated in a phase I clinical trial but failed to induce neutralizing antibodies in most subjects. In this study, we designed a novel form of E1E2 which is secreted from cells and is soluble and compared it to wild-type E1E2 by DNA immunization of mice. The results showed that this new E1E2 is more immunogenic than wild-type E1E2. Detailed mapping of the antibody responses revealed that antibodies to the conserved E2 antigenic site 412 to 423 were elicited but the serum concentrations were too low to neutralize the virus effectively. This soluble E1E2 provides a new reagent for studying HCV and for rational vaccine design. PMID:24965471

Duodenal Bacteria From Patients With Celiac Disease and Healthy Subjects Distinctly Affect Gluten Breakdown and Immunogenicity.

PubMed

Caminero, Alberto; Galipeau, Heather J; McCarville, Justin L; Johnston, Chad W; Bernier, Steve P; Russell, Amy K; Jury, Jennifer; Herran, Alexandra R; Casqueiro, Javier; Tye-Din, Jason A; Surette, Michael G; Magarvey, Nathan A; Schuppan, Detlef; Verdu, Elena F

2016-10-01

Partially degraded gluten peptides from cereals trigger celiac disease (CD), an autoimmune enteropathy occurring in genetically susceptible persons. Susceptibility genes are necessary but not sufficient to induce CD, and additional environmental factors related to unfavorable alterations in the microbiota have been proposed. We investigated gluten metabolism by opportunistic pathogens and commensal duodenal bacteria and characterized the capacity of the produced peptides to activate gluten-specific T-cells from CD patients. We colonized germ-free C57BL/6 mice with bacteria isolated from the small intestine of CD patients or healthy controls, selected for their in vitro gluten-degrading capacity. After gluten gavage, gliadin amount and proteolytic activities were measured in intestinal contents. Peptides produced by bacteria used in mouse colonizations from the immunogenic 33-mer gluten peptide were characterized by liquid chromatography tandem mass spectrometry and their immunogenic potential was evaluated using peripheral blood mononuclear cells from celiac patients after receiving a 3-day gluten challenge. Bacterial colonizations produced distinct gluten-degradation patterns in the mouse small intestine. Pseudomonas aeruginosa, an opportunistic pathogen from CD patients, exhibited elastase activity and produced peptides that better translocated the mouse intestinal barrier. P aeruginosa-modified gluten peptides activated gluten-specific T-cells from CD patients. In contrast, Lactobacillus spp. from the duodenum of non-CD controls degraded gluten peptides produced by human and P aeruginosa proteases, reducing their immunogenicity. Small intestinal bacteria exhibit distinct gluten metabolic patterns in vivo, increasing or reducing gluten peptide immunogenicity. This microbe-gluten-host interaction may modulate autoimmune risk in genetically susceptible persons and may underlie the reported association of dysbiosis and CD. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Analysis of the immunoproteome of Mycoplasma mycoides subsp. mycoides small colony type reveals immunogenic homologues to other known virulence traits in related Mycoplasma species.

PubMed

Jores, Joerg; Meens, Jochen; Buettner, Falk F R; Linz, Bodo; Naessens, Jan; Gerlach, Gerald F

2009-10-15

Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides small colony type (MmmSC) has been eradicated in the developed world, but it is still present in many countries of sub-Saharan Africa. After initially successful control measures in the 1960s it has been spreading due to a lack of money, fragmentation of veterinary services, uncontrolled cattle movement, insufficient vaccine efficacy and sensitivity of current diagnostic tests. In this study we used two-dimensional polyacrylamide gel electrophoresis followed by immunoblot with sera from MmmSC-infected animals and MALDI-ToF mass spectrometry to identify novel immunogenic proteins as candidate molecules for improved diagnostics and vaccines. We identified 24 immunogens recognized by pooled sera from experimentally infected cattle. Furthermore, a serum from an animal with acute clinical disease as well as severe pathomorphological lesions recognized 13 additional immunogens indicating variation in the antibody responses to CBPP amongst cattle. Most immunogens showed compelling similarity to protein/gene sequences in the two ruminant pathogens M. capricolum subsp. capricolum and M. mycoides subsp. mycoides large colony type both belonging to the mycoides cluster. Three of these proteins, namely glycerol-3-phosphate oxidase, adenylosuccinate synthase, and glyceraldehyde-3-phosphate dehydrogenase, had no compelling homologue in the other distantly related bovine pathogen M. agalactiae. In addition, translation elongation factor Tu, heat shock protein 70, pyruvate dehydrogenase, and FKBP-type peptidyl-prolyl isomerase, which have been found to mediate adhesion to host tissue in other mycoplasmas were shown to be expressed and recognized by sera. These proteins have potential for the development of improved diagnostic tests and possibly vaccines.

Comparison of allergenicity and immunogenicity of an intact allergen vaccine and commercially available allergoid products for birch pollen immunotherapy.

PubMed

Lund, L; Henmar, H; Würtzen, P A; Lund, G; Hjortskov, N; Larsen, J N

2007-04-01

Specific immunotherapy with intact allergen vaccine is a well-documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10-year period did not indicate increased safety of allergoids over intact allergens. The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine. Solid-phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose. IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen-specific IgG responses in mice. While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid concept.

Conjugating recombinant proteins to Pseudomonas aeruginosa ExoProtein A: a strategy for enhancing immunogenicity of malaria vaccine candidates.

PubMed

Qian, Feng; Wu, Yimin; Muratova, Olga; Zhou, Hong; Dobrescu, Gelu; Duggan, Peter; Lynn, Lambert; Song, Guanhong; Zhang, Yanling; Reiter, Karine; MacDonald, Nicholas; Narum, David L; Long, Carole A; Miller, Louis H; Saul, Allan; Mullen, Gregory E D

2007-05-16

Conjugation of polysaccharides to carrier proteins has been a successful approach for producing safe and effective vaccines. In an attempt to increase the immunogenicity of two malarial vaccine candidate proteins of Plasmodium falciparum, apical membrane antigen 1 (AMA1) to a blood stage vaccine candidate and surface protein 25 (Pfs25) a mosquito stage vaccine candidate, were each independently chemically conjugated to the mutant, nontoxic Pseudomonas aeruginosa ExoProtein A (rEPA). AMA1 is a large (66kD) relatively good immunogen in mice; Pfs25 is a poorly immunogenic protein when presented on alum to mice. Mice were immunized on days 0 and 28 with AMA1- or Pfs25-rEPA conjugates or unconjugated AMA1 or Pfs25, all formulated on Alhydrogel. Remarkably, sera from mice 14 days after the second immunization with Pfs25-rEPA conjugates displayed over a 1000-fold higher antibody titers as compared to unconjugated Pfs25. In contrast, AMA1 conjugated under the same conditions induced only a three-fold increase in antibody titers. When tested for functional activity, antibodies elicited by the AMA1-rEPA inhibited invasion of erythrocytes by blood-stage parasites and antibodies elicited by the Pfs25-rEPA conjugates blocked the development of the sexual stage parasites in the mosquito midgut. These results demonstrate that conjugation to rEPA induces a marked improvement in the antibody titer in mice for the poor immunogen (Pfs25) and for the larger protein (AMA1). These conjugates now need to be tested in humans to determine if mice are predictive of the response in humans.

Investigation of the Mechanism of Therapeutic Protein-Drug Interaction Between Methotrexate and Golimumab, an Anti-TNFα Monoclonal Antibody.

PubMed

Wang, Weirong; Leu, Jocelyn; Watson, Rebecca; Xu, Zhenhua; Zhou, Honghui

2018-04-17

A prominent example of human therapeutic protein-drug interaction (TP-DI) is between methotrexate (MTX) and anti-TNFα mAbs. One plausible mechanism for this TP-DI is through the pharmacodynamic effect of MTX on immunogenicity. However, there is no definitive evidence to substantiate this mechanism, and other competing hypotheses, such as MTX suppressing FcγRI expression thereby affecting mAb PK, have also been proposed. In order to understand this mechanism, a cynomolgus monkey study was conducted using golimumab as a model compound. Golimumab elicited high incidences of immunogenicity in healthy cynomolgus monkeys. Concomitant dosing of MTX delayed the onset and reduced the magnitude of anti-drug antibody (ADA) formation. The impact of MTX on golimumab PK correlated with the ADA status. Prior to ADA formation, MTX has no discernable effect on golimumab PK. Additionally, no alteration in FcγRI expression was observed following MTX treatment. The impact of MTX on golimumab immunogenicity and PK has been observed in patients with rheumatoid arthritis, psoriatic arthritis (PsA), and ankylosing spondylitis. In a representative phase 3 study of golimumab in patients with PsA, patients not receiving concomitant MTX was reported to have ~ 30% lower steady-state trough golimumab levels compared to those who received MTX. However, further analysis showed that PsA patients who were negative for ADA in both treatment groups had comparable trough levels of golimumab. Taken together, our results suggest that the mechanism of TP-DI between MTX and golimumab can mostly be attributed to the pharmacodynamic effect of MTX, i.e., the lowering of immunogenicity and immunogenicity-mediated clearance of mAbs.

Immunogenicity and safety of an adjuvanted herpes zoster subunit candidate vaccine in adults ≥ 50 years of age with a prior history of herpes zoster: A phase III, non-randomized, open-label clinical trial.

PubMed

Godeaux, Olivier; Kovac, Martina; Shu, Daniel; Grupping, Katrijn; Campora, Laura; Douha, Martine; Heineman, Thomas C; Lal, Himal

2017-05-04

This phase III, non-randomized, open-label, multi-center study (NCT01827839) evaluated the immunogenicity and safety of an adjuvanted recombinant subunit herpes zoster (HZ) vaccine (HZ/su) in adults aged ≥ 50 y with prior physician-documented history of HZ. Participants (stratified by age: 50-59, 60-69 and ≥ 70 y) received 2 doses of HZ/su 2 months apart and were followed-up for another 12 months. Anti-glycoprotein E (gE) antibodies were measured by enzyme-linked immunosorbent assay before vaccination and 1 month after the second dose (Month 3). Solicited local and general adverse events (AEs) were recorded for 7 d and unsolicited AEs for 30 d after each vaccination. Serious AEs were recorded until study end. The primary immunogenicity objective was met if the lower limit of the 95% confidence interval (CI) of the vaccine response rate (VRR), defined as a 4-fold increase in anti-gE over baseline, at Month 3 was ≥ 60%. 96 participants (32/age group) were enrolled. The primary immunogenicity objective was met, as the VRR at Month 3 was 90.2% (95% CI: 81.7-95.7). Geometric mean anti-gE antibody concentrations at Month 3 were similar across age groups. 77.9% and 71.6% of participants reported local and general solicited AEs, respectively. The most frequent solicited AEs were pain at injection site, fatigue, headache, myalgia and shivering. The HZ/su vaccine was immunogenic in adults aged ≥ 50 y with a physician-documented history of HZ, and no safety concerns were identified.

Safety, reactogenicity and immunogenicity of a booster dose of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Malian children.

PubMed

Dicko, Alassane; Santara, Gaoussou; Mahamar, Almahamoudou; Sidibe, Youssoufa; Barry, Amadou; Dicko, Yahia; Diallo, Aminata; Dolo, Amagana; Doumbo, Ogobara; Shafi, Fakrudeen; François, Nancy; Strezova, Ana; Borys, Dorota; Schuerman, Lode

2013-02-01

Primary vaccination with the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) was previously shown to be immunogenic and well tolerated in Malian children. Data on booster vaccination with a fourth consecutive dose of PHiD-CV are available for Europe, Asia and Latin America but are lacking for Africa. The present study evaluated further the safety, reactogenicity and immunogenicity of a fourth consecutive (booster) dose of PHiD-CV. Low incidences of AEs with grade 3 intensity (2.1% of subjects) were observed. There were no reports of large swelling reactions and serious adverse events. One month post-booster vaccination, for each vaccine pneumococcal serotype, at least 97.8% of subjects had antibody concentrations ≥ 0.2 μg/ml, and at least 97.1% of subjects had opsonophagocytic activity ≥ 8. From pre- to post-booster, a 12.3-fold increase in anti-protein D geometric mean concentration was observed. This phase III, open-label study was conducted in Ouelessebougou, Mali, between November 2009 and June 2010. The study population consisted of Malian children previously primed (3 doses) with PHiD-CV in study NCT00678301 receiving a fourth consecutive (booster) dose of PHiD-CV in the second year of life. The incidences of adverse events (AEs) with grade 3 intensity (primary objective) or of any intensity (secondary objective), and the immunogenicity (secondary objective) of the PHiD-CV booster dose were assessed. A booster dose of PHiD-CV was well tolerated when administered to Malian children in the second year of life and was highly immunogenic for all 10 vaccine pneumococcal serotypes and NTHi protein D. (ClinicalTrials.gov identifier: NCT00985465).

Matrix-M™ adjuvant enhances immunogenicity of both protein- and modified vaccinia virus Ankara-based influenza vaccines in mice.

PubMed

Magnusson, Sofia E; Altenburg, Arwen F; Bengtsson, Karin Lövgren; Bosman, Fons; de Vries, Rory D; Rimmelzwaan, Guus F; Stertman, Linda

2018-04-01

Influenza viruses continuously circulate in the human population and escape recognition by virus neutralizing antibodies induced by prior infection or vaccination through accumulation of mutations in the surface proteins hemagglutinin (HA) and neuraminidase (NA). Various strategies to develop a vaccine that provides broad protection against different influenza A viruses are under investigation, including use of recombinant (r) viral vectors and adjuvants. The replication-deficient modified vaccinia virus Ankara (MVA) is a promising vaccine vector that efficiently induces B and T cell responses specific for the antigen of interest. It is assumed that live vaccine vectors do not require an adjuvant to be immunogenic as the vector already mediates recruitment and activation of immune cells. To address this topic, BALB/c mice were vaccinated with either protein- or rMVA-based HA influenza vaccines, formulated with or without the saponin-based Matrix-M™ adjuvant. Co-formulation with Matrix-M significantly increased HA vaccine immunogenicity, resulting in antigen-specific humoral and cellular immune responses comparable to those induced by unadjuvanted rMVA-HA. Of special interest, rMVA-HA immunogenicity was also enhanced by addition of Matrix-M, demonstrated by enhanced HA inhibition antibody titres and cellular immune responses. Matrix-M added to either protein- or rMVA-based HA vaccines mediated recruitment and activation of antigen-presenting cells and lymphocytes to the draining lymph node 24 and 48 h post-vaccination. Taken together, these results suggest that adjuvants can be used not only with protein-based vaccines but also in combination with rMVA to increase vaccine immunogenicity, which may be a step forward to generate new and more effective influenza vaccines.

A phase 1, open-label, randomized study to compare the immunogenicity and safety of different administration routes and doses of virosomal influenza vaccine in elderly.

PubMed

Levin, Yotam; Kochba, Efrat; Shukarev, Georgi; Rusch, Sarah; Herrera-Taracena, Guillermo; van Damme, Pierre

2016-10-17

Influenza remains a significant problem in elderly despite widespread vaccination coverage. This randomized, phase-I study in elderly compared different strategies of improving vaccine immunogenicity. A total of 370 healthy participants (⩾65years) were randomized equally 1:1:1:1:1:1 to six influenza vaccine treatments (approximately 60-63 participants per treatment arm) at day 1 that consisted of three investigational virosomal vaccine formulations at doses of 7.5, 15, and 45μg HA antigen/strain administered intradermally (ID) by MicronJet600™ microneedle device (NanoPass Technologies) or intramuscularly (IM), and three comparator registered seasonal vaccines; Inflexal V™ (Janssen) and MF59 adjuvanted Fluad™ (Novartis) administered IM and Intanza™ (Sanofi Pasteur) administered ID via Soluvia™ prefilled microinjection system (BD). Serological evaluations were performed at days 22 and 90 and safety followed-up for 6months. Intradermal delivery of virosomal vaccine using MicronJet600™ resulted in significantly higher immunogenicity than the equivalent dose of virosomal Inflexal V™ administered intramuscularly across most of the parameters and strains, as well as in some of the readouts and strains as compared with the 45μg dose of virosomal vaccine formulation. Of 370 participants, 300 (81.1%) reported ⩾1 adverse event (AE); more participants reported solicited local AEs (72.2%) than solicited systemic AEs (12.2%). Intradermal delivery significantly improved influenza vaccine immunogenicity compared with intramuscular delivery. Triple dose (45μg) virosomal vaccine did not demonstrate any benefit on vaccine's immunogenicity over 15μg commercial presentation. All treatments were generally safe and well-tolerated. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Safety, Tolerability and Immunogenicity of Pentavalent Rotavirus Vaccine Manufactured by a Modified Process.

PubMed

Martinón-Torres, Federico; Greenberg, David; Varman, Meera; Killar, John A; Hille, Darcy; Strable, Erica L; Stek, Jon E; Kaplan, Susan S

2017-04-01

Rotavirus is the leading cause of severe diarrhea in infants and young children. The current formulation of pentavalent rotavirus vaccine (RV5) must be stored refrigerated at 2-8°C. A modified formulation of RV5 (RV5mp) has been developed with stability at 37°C for 7 days and an expiry extended to 36 months when stored at 2-8°C. This study (ClinicalTrials.gov identifier: NCT01600092; EudraCT number: 2012-001611-23) evaluated the safety, tolerability and immunogenicity of RV5mp versus the currently marketed RV5 in infants. To maintain blinding, both vaccine formulations were stored refrigerated at 2-8°C for the duration of the study. Immunogenicity endpoints were (1) serum neutralizing antibody titers to human rotavirus serotypes G1, G2, G3, G4 and P1A[8] and (2) proportion of subjects with a ≥3-fold rise from baseline for serum neutralizing antibody to human rotavirus serotypes G1, G2, G3, G4 and P1A[8] and serum antirotavirus immunoglobulin A. The RV5mp group (n = 505) and RV5 group (n = 509) had comparable safety profiles. There were no deaths and no vaccine-related serious adverse events in this study. With respect to immunogenicity, RV5mp was noninferior compared with RV5. Serum neutralizing antibody responses by country and breast-feeding status were generally consistent with the overall results. RV5mp enhances storage requirements while maintaining the immunogenicity and safety profile of the currently licensed RV5. A vaccine that is stable at room temperature may be more convenient for vaccinators, particularly in places where the cold chain is unreliable, and ultimately will permit more widespread use.

Human Papillomavirus Virus-Like Particles Are Efficient Oral Immunogens when Coadministered with Escherichia coli Heat-Labile Enterotoxin Mutant R192G or CpG DNA

PubMed Central

Gerber, S.; Lane, C.; Brown, D. M.; Lord, E.; DiLorenzo, M.; Clements, J. D.; Rybicki, E.; Williamson, A.-L.; Rose, R. C.

2001-01-01

Certain human papillomaviruses (HPVs) cause most cervical cancer, which remains a significant source of morbidity and mortality among women worldwide. HPV recombinant virus-like particles (VLPs) are promising vaccine candidates for controlling anogenital HPV disease and are now being evaluated as a parenteral vaccine modality in human subjects. Vaccines formulated for injection generally are more costly, more difficult to administer, and less acceptable to recipients than are mucosally administered vaccines. Since oral delivery represents an attractive alternative to parenteral injection for large-scale human vaccination, the oral immunogenicity of HPV type 11 (HPV-11) VLPs in mice was previously investigated; it was found that a modest systemic neutralizing antibody response was induced (R. C. Rose, C. Lane, S. Wilson, J. A. Suzich, E. Rybicki, and A. L. Williamson, Vaccine 17:2129–2135, 1999). Here we examine whether VLPs of other genotypes may also be immunogenic when administered orally and whether mucosal adjuvants can be used to enhance VLP oral immunogenicity. We show that HPV-16 and HPV-18 VLPs are immunogenic when administered orally and that oral coadministration of these antigens with Escherichia coli heat-labile enterotoxin (LT) mutant R192G (LT R192G) or CpG DNA can significantly improve anti-VLP humoral responses in peripheral blood and in genital mucosal secretions. Our results also suggest that LT R192G may be superior to CpG DNA in this ability. These findings support the concept of oral immunization against anogenital HPV disease and suggest that clinical studies involving this approach may be warranted. PMID:11312347

Safety and immunogenicity of an intramuscular quadrivalent influenza vaccine in children 3 to 8 y of age: A phase III randomized controlled study.

PubMed

Pepin, Stephanie; Szymanski, Henryk; Rochín Kobashi, Ilya Angélica; Villagomez Martinez, Sandra; González Zamora, José Francisco; Brzostek, Jerzy; Huang, Li-Min; Chiu, Cheng-Hsun; Chen, Po-Yen; Ahonen, Anitta; Forstén, Aino; Seppä, Ilkka; Quiroz, René Farfán; Korhonen, Tiina; Rivas, Enrique; Monfredo, Celine; Hutagalung, Yanee; Menezes, Josemund; Vesikari, Timo

2016-12-01

A quadrivalent, inactivated, split-virion influenza vaccine containing a strain from both B lineages (IIV4) has been developed, but its safety and immunogenicity in young children has not been described. This was a phase III, randomized, double-blind, active-controlled, multi-center study to examine the immunogenicity and safety of IIV4 in children 3-8 y of age (EudraCT no. 2011-005374-33). Participants were randomized 5:1:1 to receive the 2013/2014 Northern Hemisphere formulation of IIV4, an investigational trivalent comparator (IIV3) containing the B/Victoria lineage strain, or the licensed Northern Hemisphere IIV3 containing the B/Yamagata lineage strain. Participants who had not previously received a full influenza vaccination schedule received 2 doses of vaccine 28 d apart; all others received a single dose. 1242 children were included. For all 4 strains, IIV4 induced geometric mean haemagglutination inhibition titres non-inferior to those induced by the IIV3 comparators. For both B strains, geometric mean antibody titres induced by IIV4 were superior to those induced by the IIV3 with the alternative lineage strain. Similar proportions of participants vaccinated with IIV4 and IIV3 reported solicited injection-site reactions, solicited systemic reactions, and vaccine-related adverse events. A single vaccine-related serious adverse event, thrombocytopenia, was reported 9 d after vaccination with IIV4 and resolved without sequelae. In conclusion, in children aged 3-8 y who received one dose or 2 doses 28 d apart, IIV4 had an acceptable safety profile, was as immunogenic as IIV3 for the shared strains, and had superior immunogenicity for the additional B strain.

Immunogenicity and safety assessment of a trivalent, inactivated split influenza vaccine in Korean children: Double-blind, randomized, active-controlled multicenter phase III clinical trial.

PubMed

Han, Seung Beom; Rhim, Jung-Woo; Shin, Hye Jo; Lee, Soo Young; Kim, Hyun-Hee; Kim, Jong-Hyun; Lee, Kyung-Yil; Ma, Sang Hyuk; Park, Joon Soo; Kim, Hwang Min; Kim, Chun Soo; Kim, Dong Ho; Choi, Young Youn; Cha, Sung-Ho; Hong, Young Jin; Kang, Jin Han

2015-01-01

A multicenter, double-blind, randomized, active-control phase III clinical trial was performed to assess the immunogenicity and safety of a trivalent, inactivated split influenza vaccine. Korean children between the ages of 6 months and 18 y were enrolled and randomized into a study (study vaccine) or a control vaccine group (commercially available trivalent, inactivated split influenza vaccine) in a 5:1 ratio. Antibody responses were determined using hemagglutination inhibition assay, and post-vaccination immunogenicity was assessed based on seroconversion and seroprotection rates. For safety assessment, solicited local and systemic adverse events up to 28 d after vaccination and unsolicited adverse events up to 6 months after vaccination were evaluated. Immunogenicity was assessed in 337 and 68 children of the study and control groups. In the study vaccine group, seroconversion rates against influenza A/H1N1, A/H3N2, and B strains were 62.0% (95% CI: 56.8-67.2), 53.4% (95% CI: 48.1-58.7), and 54.9% (95% CI: 48.1-60.2), respectively. The corresponding seroprotection rates were 95.0% (95% CI: 92.6-97.3), 93.8% (95% CI: 91.2-96.4), and 95.3% (95% CI: 93.0-97.5). The lower 95% CI limits of the seroconversion and seroprotection rates were over 40% and 70%, respectively, against all strains. Seroconversion and seroprotection rates were not significantly different between the study and control vaccine groups. Furthermore, the frequencies of adverse events were not significantly different between the 2 vaccine groups, and no serious vaccination-related adverse events were noted. In conclusion, the study vaccine exhibited substantial immunogenicity and safety in Korean children and is expected to be clinically effective.

Immunogenic proteins of Brucella abortus to minimize cross reactions in brucellosis diagnosis.

PubMed

Ko, Kyung Yuk; Kim, Jong-Wan; Her, Moon; Kang, Sung-Il; Jung, Suk Chan; Cho, Dong Hee; Kim, Ji-Yeon

2012-05-04

To overcome the limitations of serological diagnosis, including false positive reactions caused by other pathogens, specific antigens for diagnosis of brucellosis other than LPS have been required. The present study was conducted to separate and identify immuno-dominant insoluble proteins of Brucella abortus against the antisera of cattle infected with B. abortus, or/and Yersinia enterocolitica, or the sera of non-infected cattle. After separating insoluble proteins of B. abortus by two dimensional electrophoresis (2-DE), their immuno-reactivity was determined by western blotting. A portion of the immunogenic spots against the positive antisera of B. abortus that have the potential for use as specific antigens were identified by MS/MS analysis. Overall, 18 immunogenic insoluble proteins of B. abortus 1119-3 showed immuno-reactivity against only the positive antisera of B. abortus, but failed to have immunogenicity toward both the positive sera of Y. enterocolitica and the negative sera of B. abortus. Identification of these proteins revealed the following: F0F1 ATP synthase subunit β, solute-binding family 5 protein, 28 kDa OMP, Leu/Ile/Val-binding family protein, Histidinol dehyddrogenase, Hypothetical protein, Twin-arginine translocation pathway signal sequence domain-containing protein, Dihydroorotase, Serine protease family protein, β-hydroxyacyl-(acyl-carrier-protein) dehydratase FabA, Short-chain dehydrogenase-/reductase carbonic anhydrase, Orinithine carbamoyltransferase, Leucyl aminopeptidase, Cold shock DNA-binding domain-containing protein, Cu/Zn superoxide dismutase, and Methionine aminopeptidase. The 18 immunogenic proteins separated in the present study can be considered candidate antigens to minimize cross reaction in the diagnosis of brucellosis and useful sources for Brucella vaccine development. Copyright © 2011 Elsevier B.V. All rights reserved.

Food Processing: The Influence of the Maillard Reaction on Immunogenicity and Allergenicity of Food Proteins

PubMed Central

Teodorowicz, Malgorzata; van Neerven, Joost

2017-01-01

The majority of foods that are consumed in our developed society have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars, the Maillard reaction (MR). Maillard reaction products (MRPs) contribute to the taste, smell and color of many food products, and thus influence consumers’ choices. However, in recent years, MRPs have been linked to the increasing prevalence of diet- and inflammation-related non-communicable diseases including food allergy. Although during the last years a better understanding of immunogenicity of MRPs has been achieved, still only little is known about the structural/chemical characteristics predisposing MRPs to interact with antigen presenting cells (APCs). This report provides a comprehensive review of recent studies on the influence of the Maillard reaction on the immunogenicity and allergenicity of food proteins. PMID:28777346

Reduced immunogenicity of diphtheria and tetanus toxoids when combined with pertussis toxoid.

PubMed

Trollfors, Birger; Taranger, John; Lagergård, Teresa; Sundh, Valter

2005-01-01

The effect of pertussis toxoid on the immunogenicity of diphtheria and tetanus toxoids (DT) was studied during a double blind efficacy trial of an acellular pertussis vaccine. Infants received DT with or without pertussis toxoid at 3, 5 and 12 months of age. Geometric mean concentrations were higher in the DT than in the DT-pertussis toxoid group 1 month (diphtheria toxoid 4.76 versus 3.58 IU/mL, P = 0.009; tetanus toxoid 4.42 versus 2.66 IU/mL, P < 0.0001) and 2 years after the third injection (diphtheria toxoid 0.15 versus 0.10 IU/mL, P < 0.0001; tetanus toxoid 0.38 versus 0.18 IU/mL, P < 0.0001). Pertussis toxoid causes a small but significant reduction of the immunogenicity of diphtheria toxoid and tetanus toxoid.

Acellular pertussis vaccine boosters combined with diphtheria and tetanus toxoid boosters for adolescents: safety and immunogenicity assessment when preceded by different 5-dose DTaP/DTwP schedules.

PubMed

Pichichero, Michael E; Casey, Janet R; Francis, Anne B; Marsocci, Steven M; Murphy, Marie; Hoeger, William; Cleary, Carolyn

2006-09-01

A sixth dose of tetanus, diphtheria, acellular pertussis (Tdap) vaccine in adolescents might produce a differing reactogenicity and/or immunogenicity response depending on the composition of the 5 prior doses of DTaP or DT-whole cell pertussis (DTwP) vaccine. Reactions and immune responses following receipt of the Sanofi Pasteur (Adacel) and GlaxoSmithKline (Boostrix) Tdap vaccines were assessed in 229 adolescents. No differences were observed for reactions to either Tdap vaccine regardless of the prior DTaP/DTwP vaccination history. Seroprotective levels and antibody concentrations were comparable regardless of prior DTaP/DTwP vaccine history. A sixth sequential dose of Tdap after 5 doses of DTaP appears safe and immunogenic.

Virus-like particles as a vaccine delivery system: myths and facts.

PubMed

Roy, Polly; Noad, Rob

2009-01-01

Vaccines against viral disease have traditionally relied on attenuated virus strains or inactivation of infectious virus. Subunit vaccines based on viral proteins expressed in heterologous systems have been effective for some pathogens, but have often suffered from poor immunogenicity due to incorrect protein folding or modification. In this chapter we focus on a specific class of viral subunit vaccine that mimics the overall structure of virus particles and thus preserves the native antigenic conformation of the immunogenic proteins. These virus-like particles (VLPs) have been produced for a wide range of taxonomically and structurally distinct viruses, and have unique advantages in terms of safety and immunogenicity over previous approaches. With new VLP vaccines for papillomavirus beginning to reach the market place we argue that this technology has now 'come-of-age' and must be considered a viable vaccine strategy.

Immunogenic activity of the fish tapeworm Pterobothrium heteracanthum (Trypanorhyncha: Pterobothriidae) in BALB/c mice.

PubMed

Mattos, D P B G; Verícimo, M A; Lopes, L M S; São Clemente, S C

2015-03-01

The aim of this study was to verify the immunogenicity of Pterobothrium heteracanthum (Cestoda: Trypanorhyncha) crude protein extract (PH-CPE) in BALB/c mice. The parasites were obtained from Micropogonias furnieri (Osteichthyes: Sciaenidae). Groups of six mice were each immunized with 10, 50 or 100 μg of PH-CPE, on days 0 and 35. Both specific IgG and IgE responses were developed after immunization. The immunoblot assay revealed that specific IgG recognizes PH-CPE proteins with two molecular weight ranges, 60-75 and 30-40 kDa, and that IgE recognizes larger proteins over 120 kDa. This appears to be the first report on the immunogenicity of metacestodes within the Pterobothriidae and that PH-CPE is a potential inducer of a specific IgE response.

An update on safety and immunogenicity of vaccines containing emulsion-based adjuvants.

PubMed

Fox, Christopher B; Haensler, Jean

2013-07-01

With the exception of alum, emulsion-based vaccine adjuvants have been administered to far more people than any other adjuvant, especially since the 2009 H1N1 influenza pandemic. The number of clinical safety and immunogenicity evaluations of vaccines containing emulsion adjuvants has correspondingly mushroomed. In this review, the authors introduce emulsion adjuvant composition and history before detailing the most recent findings from clinical and postmarketing data regarding the effects of emulsion adjuvants on vaccine immunogenicity and safety, with emphasis on the most widely distributed emulsion adjuvants, MF59® and AS03. The authors also present a summary of other emulsion adjuvants in clinical development and indicate promising avenues for future emulsion-based adjuvant development. Overall, emulsion adjuvants have demonstrated potent adjuvant activity across a number of disease indications along with acceptable safety profiles.

Coiled-Coil Irregularities and Instabilities in Group A Streptococcus M1 Are Required for Virulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

McNamara, Case; Zinkernagel, Annelies S.; Macheboeuf, Pauline

2008-07-21

Antigenically variable M proteins are major virulence factors and immunogens of the human pathogen group A Streptococcus (GAS). Here, we report the -3 angstrom resolution structure of a GAS M1 fragment containing the regions responsible for eliciting type-specific, protective immunity and for binding fibrinogen, which promotes M1 proinflammatory and antiphagocytic functions. The structure revealed substantial irregularities and instabilities throughout the coiled coil of the M1 fragment. Similar structural irregularities occur in myosin and tropomyosin, explaining the patterns of cross-reactivity seen in autoimmune sequelae of GAS infection. Sequence idealization of a large segment of the M1 coiled coil enhanced stability butmore » diminished fibrinogen binding, proinflammatory effects, and antibody cross-reactivity, whereas it left protective immunogenicity undiminished. Idealized M proteins appear to have promise as vaccine immunogens.« less

Comparative effects of carrier proteins on vaccine-induced immune response.

PubMed

Knuf, Markus; Kowalzik, Frank; Kieninger, Dorothee

2011-07-12

The efficacy of vaccines against major encapsulated bacterial pathogens -Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae type b (Hib) - has been significantly enhanced by conjugating the respective polysaccharides with different carrier proteins: diphtheria toxoid; non-toxic cross-reactive material of diphtheria toxin(197), tetanus toxoid, N. meningitidis outer membrane protein, and non-typeable H. influenzae-derived protein D. Hib, meningococcal, and pneumococcal conjugate vaccines have shown good safety and immunogenicity profiles regardless of the carrier protein used, although data are conflicting as to which carrier protein is the most immunogenic. Coadministration of conjugate vaccines bearing the same carrier protein has the potential for inducing either positive or negative effects on vaccine immunogenicity (immune interference). Clinical studies on the coadministration of conjugate vaccines reveal conflicting data with respect to immune interference and vaccine efficacy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Food Processing: The Influence of the Maillard Reaction on Immunogenicity and Allergenicity of Food Proteins.

PubMed

Teodorowicz, Malgorzata; van Neerven, Joost; Savelkoul, Huub

2017-08-04

The majority of foods that are consumed in our developed society have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars, the Maillard reaction (MR). Maillard reaction products (MRPs) contribute to the taste, smell and color of many food products, and thus influence consumers' choices. However, in recent years, MRPs have been linked to the increasing prevalence of diet- and inflammation-related non-communicable diseases including food allergy. Although during the last years a better understanding of immunogenicity of MRPs has been achieved, still only little is known about the structural/chemical characteristics predisposing MRPs to interact with antigen presenting cells (APCs). This report provides a comprehensive review of recent studies on the influence of the Maillard reaction on the immunogenicity and allergenicity of food proteins.

Association between mitogenicity and immunogenicity of 4-hydroxy-3,5- dinitrophenacetyl-lipopolysaccharide, a T-independent antigen

PubMed Central

1976-01-01

Polymyxin B, which is a basic polypeptide produced by various strains of Bacillus Polymyxa, has previously been shown to prevent the lethal effect of LPS and to neutralize the Schwartzmann reaction. In this study we have investigated the interactions between polymyxin B and lipopolysaccharide (LPS) and hapten LPS conjugates. Polymyxin B was found to suppress mitogenicity of LPS and also to inhibit immunogenicity of the hapten conjugate 4-hydroxy-3,5-dinitrophenacetyl (NNP)-LPS. Inhibition was not due to interference with the expression of NNP determinants nor to cross-reactivity between PB and the hapten. Since mitogenicity and immunogenicity decreased in parallel, we conclude that B-cell activation in specific thymus independent responses does not take place in the absence of a nonspecific (non-Ig- mediated) signal. PMID:178823

An overview on Leishmania vaccines: A narrative review article.

PubMed

Rezvan, Hossein; Moafi, Mohammad

2015-01-01

Leishmaniasis is one of the major health problems and categorized as a class I disease (emerging and uncontrolled) by World Health Organization (WHO), causing highly significant morbidity and mortality. Indeed, more than 350 million individuals are at risk of Leishmania infection, and about 1.6 million new cases occur causing more than 50 thousands death annually. Because of the severe toxicity and drug resistance, present chemotherapy regimen against diverse forms of Leishmania infections is not totally worthwhile. However, sound immunity due to natural infection, implies that vigor cellular immunity against Leishmania parasites, via their live, attenuated or killed forms, can be developed in dogs and humans. Moreover, genetically conserved antigens (in most of Leishmania species), and components of sand fly saliva confer potential immunogenic molecules for Leishmania vaccination. Vaccines successes in animal studies and some clinical trials clearly justify more researches and investments illuminating opportunities in suitable vaccine designation.

An overview on Leishmania vaccines: A narrative review article

PubMed Central

Rezvan, Hossein; Moafi, Mohammad

2015-01-01

Leishmaniasis is one of the major health problems and categorized as a class I disease (emerging and uncontrolled) by World Health Organization (WHO), causing highly significant morbidity and mortality. Indeed, more than 350 million individuals are at risk of Leishmania infection, and about 1.6 million new cases occur causing more than 50 thousands death annually. Because of the severe toxicity and drug resistance, present chemotherapy regimen against diverse forms of Leishmania infections is not totally worthwhile. However, sound immunity due to natural infection, implies that vigor cellular immunity against Leishmania parasites, via their live, attenuated or killed forms, can be developed in dogs and humans. Moreover, genetically conserved antigens (in most of Leishmania species), and components of sand fly saliva confer potential immunogenic molecules for Leishmania vaccination. Vaccines successes in animal studies and some clinical trials clearly justify more researches and investments illuminating opportunities in suitable vaccine designation. PMID:25992245

Immunogenicity of MenACWY-CRM in Korean Military Recruits: Influence of Tetanus-Diphtheria Toxoid Vaccination on the Vaccine Response to MenACWY-CRM.

PubMed

Kim, Han Wool; Park, In Ho; You, Sooseong; Yu, Hee Tae; Oh, In Soo; Sung, Pil Soo; Shin, Eui Cheol; Kim, Kyung Hyo

2016-11-01

The quadrivalent meningococcal conjugate vaccine (MenACWY-CRM) has been introduced for military recruits in Korea since 2012. This study was performed to evaluate the immunogenicity of MenACWY-CRM in Korean military recruits. In addition, the influence of tetanus-diphtheria toxoids (Td) vaccination on the vaccine response to MenACWY-CRM was analyzed. A total of 75 military recruits were enrolled. Among them, 18 received a dose of MenACWY-CRM only (group 1), and 57 received Td three days before MenACWY-CRM immunization (group 2). The immunogenicity of MenACWY-CRM was compared between the two groups. The serum bactericidal activity with baby rabbit complement was measured before and three weeks after immunization against serogroups A, C, W-135, and Y. The geometric mean titers (GMTs) against four serogroups were significantly increased in both groups after immunization. Compared to group 2, group 1 exhibited significantly higher vaccine responses in several aspects: post-immune GMTs against serogroup A and C, seroresponse rates against serogroup A, and a fold increases of titers against serogroup A, C, and Y. MenACWY-CRM was immunogenic against all vaccine-serogroups in Korean military recruits. Vaccine response to MenACWY-CRM was influenced by Td administered three days earlier.

The corn smut-made cholera oral vaccine is thermostable and induces long-lasting immunity in mouse.

PubMed

Monreal-Escalante, Elizabeth; Navarro-Tovar, Gabriela; León-Gallo, Amalia; Juárez-Montiel, Margarita; Becerra-Flora, Alicia; Jiménez-Bremont, Juan Francisco; Rosales-Mendoza, Sergio

2016-09-20

The use of corn smut for the production of recombinant vaccines has been recently implemented by our group. In this study, the stability and immunogenic properties of the corn smut-based cholera vaccine, based on the cholera toxin B subunit (CTB), were determined in mouse. The immunogenic potential of distinct corn smut CTB doses ranging from 1 to 30μg were assessed, with maximum humoral responses at both the systemic (IgG) and intestinal (IgA) levels at a dose of 15μg. The humoral response last for up to 70days after the third boost. Mice were fully protected against a challenge with cholera toxin after receiving three 15μg-doses. Remarkably, the corn smut-made vaccine retained its immunogenic activity after storage at room temperature for a period of 1year and no reduction on CTB was observed following exposure at 50°C for 2h. These data support the use of the corn smut-made CTB vaccine as a highly stable and effective immunogen and justify its evaluation in target animal models, such as piglet and sheep, as well as clinical evaluations in humans. Copyright © 2016 Elsevier B.V. All rights reserved.

Clinical concerns of immunogenicity produced at cellular levels by biopharmaceuticals following their parenteral administration into human body.

PubMed

Tamilvanan, Shunmugaperumal; Raja, Natarajan Livingston; Sa, Biswanath; Basu, Sanat Kumar

2010-08-01

Similar to the low molecular weight traditional drugs, biopharmaceuticals are capable of producing not only therapeutic effects but also side effects provided if the dose of these compounds exceeds certain concentration and/or if the exposure duration of these compounds at subtoxic doses is being lengthened. In addition, a major drawback of biopharmaceuticals is the risk of antibody formation. Following the administration of biopharmaceuticals into human body, the formation of antidrug-antibody (ADA) or neutralizing antibody and other general immune system effects (including allergy, anaphylaxis, or serum sickness) are of clinical concern regarding therapeutic efficacy and patient safety. For example, drug-induced neutralizing antibodies to erythropoietin (EPO) result in pure red cell aplasia, whereas drug-induced acquired anti-factor VIII antibodies worsen the pathology associated with hemophilia. Since most of the already developed or under development biopharmaceuticals are to some extent immunogenic, the regulatory agencies insist to conduct potential ADA formation during the drug development process itself. This review encompasses a short overview on the clinical concerns of immunogenicity produced at cellular levels by growth hormone, interferon-alpha, EPO, factor VIII, and factor IX following their parenteral administration into human body. Clinical concerns related to immunogenicity produced by the biosimilar versions of these drugs are also presented wherever possible.

HIV-1 Immunogen: an overview of almost 30 years of clinical testing of a candidate therapeutic vaccine.

PubMed

Graziani, Gina M; Angel, Jonathan B

2016-07-01

Although current antiretroviral therapy (ART) has transformed HIV infection into a chronic, manageable disease, ART does not cure HIV infection. Furthermore, the majority of the world's infected individuals live in resource-limited countries in which access to ART is limited. Thus, the development of an effective therapeutic HIV vaccine would be an invaluable treatment alternative. Developed by the late Dr. Jonas Salk, HIV-1 Immunogen (Remune®) is a candidate therapeutic vaccine that has been studied in thousands of HIV-infected individuals in more than a dozen clinical trials during almost three decades. This Drug Evaluation, which summarizes the results of these trials that have shown the vaccine to be safe and immunogenic, also discusses the contradictory and controversial conclusions drawn from the phases 2, 2/3 and 3 trials that assessed the clinical efficacy of this vaccine. Given the lack of unequivocal clinical benefits of HIV-1 Immunogen despite almost 30 years of extensive testing, it does not appear, in our view, that this vaccine is a clinically effective immunotherapy. However, inclusion of this vaccine in the newly proposed 'Kick/Shock and Kill' strategy for HIV eradication, or use as a prophylactic vaccine, could be considered for future trials.

Effect of immunodepletion of MHC class II-positive cells from pancreatic islets on generation of cytotoxic T-lymphocytes in mixed islet-lymphocyte coculture.

PubMed

Stock, P G; Ascher, N L; Platt, J L; Kaufman, D B; Chen, S; Field, M J; Sutherland, D E

1989-01-01

In vitro manipulation of pancreatic islets to decrease islet immunogenicity before transplantation has largely been directed at eliminating the major histocompatibility complex (MHC) class II-positive passenger leukocytes from the islets. The mixed islet-lymphocyte coculture (MILC) system was used to quantitate the efficacy of immunodepletion of MHC class II-positive cells from pancreatic islets in terms of reducing immunogenicity. With these experiments we compared the in vitro immunogenicity of MHC class II-depleted islets with untreated islets. B10.BR (H-2k) islets were treated with anti-Iak alloserum followed by complement. This treatment successfully eliminated MHC class II-positive cells from the islets, as demonstrated by indirect immunofluorescence techniques. Depleted islets generated slightly lower amounts of allospecific cytotoxic T-lymphocyte (CTL) activity when exposed to C57BL/6 (H-2b) splenocytes in the MILC than untreated control islets. Although the amount of CTL generated by the depleted islets was slightly less than that generated by untreated islets, there was significant stimulation of CTL by the MHC class II-depleted islets. Therefore, the presence or absence of MHC class II cells within the islet is unlikely to be the decisive factor contributing to islet immunogenicity.

Evaluation of the use of various rat strains for immunogenic potency tests of Sabin-derived inactivated polio vaccines.

PubMed

Someya, Yuichi; Ami, Yasushi; Takai-Todaka, Reiko; Fujimoto, Akira; Haga, Kei; Murakami, Kosuke; Fujii, Yoshiki; Shirato, Haruko; Oka, Tomoichiro; Shimoike, Takashi; Katayama, Kazuhiko; Wakita, Takaji

2018-03-01

Slc:Wistar rats have been the only strain used in Japan for purpose of evaluating a national reference vaccine for the Sabin-derived inactivated polio vaccine (sIPV) and the immunogenicity of sIPV-containing products. However, following the discovery that the Slc:Wistar strain was genetically related to the Fischer 344 strain, other "real" Wistar strains, such as Crlj:WI, that are available worldwide were tested in terms of their usefulness in evaluating the immunogenicity of the past and current lots of a national reference vaccine. The response of the Crlj:WI rats against the serotype 1 of sIPV was comparable to that of the Slc:Wistar rats, while the Crlj:WI rats exhibited a higher level of response against the serotypes 2 and 3. The immunogenic potency units of a national reference vaccine determined using the Slc:Wistar rats were reproduced on tests using the Crlj:WI rats. These results indicate that a titer of the neutralizing antibody obtained in response to a given dose of sIPV cannot be directly compared between these two rat strains, but that, more importantly, the potency units are almost equivalent for the two rat strains. Copyright © 2018 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

2016 White Paper on recent issues in bioanalysis: focus on biomarker assay validation (BAV): (Part 3 - LBA, biomarkers and immunogenicity).

PubMed

Richards, Susan; Amaravadi, Lakshmi; Pillutla, Renuka; Birnboeck, Herbert; Torri, Albert; Cowan, Kyra J; Papadimitriou, Apollon; Garofolo, Fabio; Satterwhite, Christina; Piccoli, Steven; Wu, Bonnie; Krinos-Fiorotti, Corinna; Allinson, John; Berisha, Flora; Cocea, Laurent; Croft, Stephanie; Fraser, Stephanie; Galliccia, Fabrizio; Gorovits, Boris; Gupta, Swati; Gupta, Vinita; Haidar, Sam; Hottenstein, Charles; Ishii-Watabe, Akiko; Jani, Darshana; Kadavil, John; Kamerud, John; Kramer, Daniel; Litwin, Virginia; Lima Santos, Gustavo Mendes; Nelson, Robert; Ni, Yan; Pedras-Vasconcelos, João; Qiu, Yongchang; Rhyne, Paul; Safavi, Afshin; Saito, Yoshiro; Savoie, Natasha; Scheibner, Kara; Schick, Eginhard; Siguenza, Patricia Y; Smeraglia, John; Staack, Roland F; Subramanyam, Meena; Sumner, Giane; Thway, Theingi; Uhlinger, David; Ullmann, Martin; Vitaliti, Alessandra; Welink, Jan; Whiting, Chan C; Xue, Li; Zeng, Rong

2016-12-01

The 2016 10th Workshop on Recent Issues in Bioanalysis (10th WRIB) took place in Orlando, Florida with participation of close to 700 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations, and regulatory agencies worldwide. WRIB was once again a weeklong event - A Full Immersion Week of Bioanalysis for PK, Biomarkers and Immunogenicity. As usual, it is specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecules involving LCMS, hybrid LBA/LCMS, and LBA approaches, with the focus on PK, biomarkers and immunogenicity. This 2016 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. This White Paper is published in 3 parts due to length. This part (Part 3) discusses the recommendations for large molecule bioanalysis using LBA, biomarkers and immunogenicity. Parts 1 (small molecule bioanalysis using LCMS) and Part 2 (Hybrid LBA/LCMS and regulatory inputs from major global health authorities) have been published in the Bioanalysis journal, issues 22 and 23, respectively.

First-in-Human Randomized Controlled Trial of Mosaic HIV-1 Immunogens Delivered via a Modified Vaccinia Ankara Vector.

PubMed

Baden, Lindsey R; Walsh, Stephen R; Seaman, Michael S; Cohen, Yehuda Z; Johnson, Jennifer A; Licona, J Humberto; Filter, Rachel D; Kleinjan, Jane A; Gothing, Jon A; Jennings, Julia; Peter, Lauren; Nkolola, Joseph; Abbink, Peter; Borducchi, Erica N; Kirilova, Marinela; Stephenson, Kathryn E; Pegu, Poonam; Eller, Michael A; Trinh, Hung V; Rao, Mangala; Ake, Julie A; Sarnecki, Michal; Nijs, Steven; Callewaert, Katleen; Schuitemaker, Hanneke; Hendriks, Jenny; Pau, Maria G; Tomaka, Frank; Korber, Bette T; Alter, Galit; Dolin, Raphael; Earl, Patricia L; Moss, Bernard; Michael, Nelson L; Robb, Merlin L; Barouch, Dan H

2018-04-13

Mosaic immunogens are bioinformatically engineered HIV-1 sequences designed to elicit clade independent coverage against globally circulating HIV-1 strains. This Phase 1 double-blind, randomized, placebo-controlled trial enrolled healthy HIV uninfected adults who received two doses of a modified vaccinia Ankara (MVA) vectored HIV-1 bivalent mosaic immunogen vaccine or placebo on days 0 and 84. Two groups were enrolled: those who were HIV-1 vaccine naïve (N=15) and those who had received an HIV-1 vaccine four to six years earlier (Ad26.ENVA.01, N=10). We performed pre-specified blinded cellular and humoral immunogenicity analyses at days 0, 14, 28, 84, 98, 112, 168, 270, and 365. All 50 planned vaccinations were administered. Vaccination was safe and generally well tolerated. No vaccine-related serious adverse events occurred. Both cellular and humoral cross-clade immune responses were elicited after one or two vaccinations in all participants in the HIV-1 vaccine naïve group. Env-specific responses were induced after a single immunization in nearly all subjects who had previously received the prototype Ad26.ENVA.01 vaccine. No safety concerns were identified and multi-clade HIV-1 specific immune responses were elicited. http://www.clinicaltrials.gov/ Identifier: NCT02218125.

Genipin crosslinking reduced the immunogenicity of xenogeneic decellularized porcine whole-liver matrices through regulation of immune cell proliferation and polarization

NASA Astrophysics Data System (ADS)

Wang, Yujia; Bao, Ji; Wu, Xiujuan; Wu, Qiong; Li, Yi; Zhou, Yongjie; Li, Li; Bu, Hong

2016-04-01

Decellularized xenogeneic whole-liver matrices are plausible biomedical materials for the bioengineering of liver transplantation. A common method to reduce the inflammatory potential of xenogeneic matrices is crosslinking. Nevertheless, a comprehensive analysis of the immunogenic features of cross-linked decellularized tissue is still lacking. We aimed to reduce the immunogenicity of decellularized porcine whole-liver matrix through crosslinking with glutaraldehyde or genipin, a new natural agent, and investigated the mechanism of the immune-mediated responses. The histologic assessment of the host’s immune reaction activated in response to these scaffolds, as well as the M1/M2 phenotypic polarization profile of macrophages, was studied in vivo. The genipin-fixed scaffold elicited a predominantly M2 phenotype response, while the glutaraldehyde-fixed scaffold resulted in disrupted host tissue remodeling and a mixed macrophage polarization profile. The specific subsets of immune cells involved in the responses to the scaffolds were identified in vitro. Crosslinking alleviated the host response by reducing the proliferation of lymphocytes and their subsets, accompanied by a decreased release of both Th1 and Th2 cytokines. Therefore, we conclude that the natural genipin crosslinking could lower the immunogenic potential of xenogeneic decellularized whole-liver scaffolds.

The modulation of Dicer regulates tumor immunogenicity in melanoma

PubMed Central

Hoffend, Nicholas C.; Magner, William J.; Tomasi, Thomas B.

2016-01-01

MicroRNAs (miRs) are small non-coding RNAs that regulate most cellular protein networks by targeting mRNAs for translational inhibition or degradation. Dicer, a type III endoribonuclease, is a critical component in microRNA biogenesis and is required for mature microRNA production. Abnormal Dicer expression occurs in numerous cancer types and correlates with poor patient prognosis. For example, increased Dicer expression in melanoma is associated with more aggressive tumors (higher tumor mitotic index and depth of invasion) and poor patient prognosis. However, the role that Dicer plays in melanoma development and immune evasion remains unclear. Here, we report on a newly discovered relationship between Dicer expression and tumor immunogenicity. To investigate Dicer's role in regulating melanoma immunogenicity, Dicer knockdown studies were performed. We found that B16F0-Dicer deficient cells exhibited decreased tumor growth compared to control cells and were capable of inducing anti-tumor immunity. The decrease in tumor growth was abrogated in immunodeficient NSG mice and was shown to be dependent upon CD8+ T cells. Dicer knockdown also induced a more responsive immune gene profile in melanoma cells. Further studies demonstrated that CD8+ T cells preferentially killed Dicer knockdown tumor cells compared to control cells. Taken together, we present evidence which links Dicer expression to tumor immunogenicity in melanoma. PMID:27356752

The modulation of Dicer regulates tumor immunogenicity in melanoma.

PubMed

Hoffend, Nicholas C; Magner, William J; Tomasi, Thomas B

2016-07-26

MicroRNAs (miRs) are small non-coding RNAs that regulate most cellular protein networks by targeting mRNAs for translational inhibition or degradation. Dicer, a type III endoribonuclease, is a critical component in microRNA biogenesis and is required for mature microRNA production. Abnormal Dicer expression occurs in numerous cancer types and correlates with poor patient prognosis. For example, increased Dicer expression in melanoma is associated with more aggressive tumors (higher tumor mitotic index and depth of invasion) and poor patient prognosis. However, the role that Dicer plays in melanoma development and immune evasion remains unclear. Here, we report on a newly discovered relationship between Dicer expression and tumor immunogenicity. To investigate Dicer's role in regulating melanoma immunogenicity, Dicer knockdown studies were performed. We found that B16F0-Dicer deficient cells exhibited decreased tumor growth compared to control cells and were capable of inducing anti-tumor immunity. The decrease in tumor growth was abrogated in immunodeficient NSG mice and was shown to be dependent upon CD8+ T cells. Dicer knockdown also induced a more responsive immune gene profile in melanoma cells. Further studies demonstrated that CD8+ T cells preferentially killed Dicer knockdown tumor cells compared to control cells. Taken together, we present evidence which links Dicer expression to tumor immunogenicity in melanoma.

An immunogen synthesis strategy for the development of specific anti-deoxynivalenol monoclonal antibodies.

PubMed

Sanders, Melanie; Guo, Yirong; Iyer, Abhishek; García, Yara Ruiz; Galvita, Anastasia; Heyerick, Arne; Deforce, Dieter; Risseeuw, Martijn D P; Van Calenbergh, Serge; Bracke, Marc; Eremin, Sergei; Madder, Annemieke; De Saeger, Sarah

2014-01-01

An immunogen synthesis strategy was designed to develop anti-deoxynivalenol (DON) monoclonal antibodies with low cross-reactivity against structurally similar trichothecenes. A total of eight different DON immunogens were synthesised, differing in the type and position of the linker on the DON molecule. After immunisation, antisera from mice immunised with different DON immunogens were checked for the presence of relevant antibodies. Then, both homologous and heterologous enzyme-linked immunosorbent assays (ELISAs) were performed for hybridoma screening. Finally, three monoclonal antibodies against DON and its analogues were generated. In addition, monoclonal antibody 13H1 could recognise DON and its analogues in the order of HT-2 toxin > 15-acetyldeoxynivalenol (15-ADON) > DON, with IC₅₀ ranging from 1.14 to 2.13 µg ml⁻¹. Another monoclonal antibody 10H10 manifested relatively close sensitivities to DON, 3-acetyldeoxynivalenol (3-ADON) and 15-ADON, with IC₅₀ values of 22, 15 and 34 ng ml⁻¹, respectively. Using an indirect ELISA format decreases the 10H10 sensitivity to 15-ADON with 92%. A third monoclonal antibody 2A9 showed to be very specific and sensitive to 3-ADON, with IC₅₀ of 0.38 ng ml⁻¹. Using both 2A9 and 10H10 monoclonal antibodies allows determining sole DON contamination.

Effect of receptor binding specificity on the immunogenicity and protective efficacy of influenza virus A H1 vaccines

PubMed Central

Sun, Xiangjie; Cao, Weiping; Pappas, Claudia; Liu, Feng; Katz, Jacqueline M.; Tumpey, Terrence M.

2018-01-01

The biological basis for the poor immunogenicity of unadjuvanted avian influenza A virus vaccines in mammals is not well understood. Here, we mutated the hemagglutinin (HA) of two H1N1 virus vaccines to determine whether virus receptor binding specificity contributes to the low immunogenicity of avian influenza virus vaccines. Mutations were introduced into the HA of an avian influenza virus, A/Duck/New York/15024–21/96 (Dk/96) which switched the binding preference from α2,3- to α2,6-linked sialic acid (SA). A switch in receptor specificity of the human A/South Carolina/1/18 (SC/18) virus generated a mutant virus with α2,3 SA (avian) binding preference. Inactivated vaccines were generated and administered to mice and ferrets intramuscularly. We found that the vaccines with human receptor binding preference induced slightly higher antibody titers and cell-mediated immune responses compared to their isogenic viruses with avian receptor binding specificity. Upon challenge with DK/96 or SC18 virus, differences in lung virus titers between the vaccine groups with different receptor-binding specificities were minimal. Overall, our data suggest that receptor binding specificity contributes only marginally to the immunogenicity of avian influenza vaccines and that other factors may also be involved. PMID:25078114

Immunogenicity of virus-like particles containing modified goose parvovirus VP2 protein.

PubMed

Chen, Zongyan; Li, Chuanfeng; Zhu, Yingqi; Wang, Binbin; Meng, Chunchun; Liu, Guangqing

2012-10-01

The major capsid protein VP2 of goose parvovirus (GPV) expressed using a baculovirus expression system (BES) assembles into virus-like particles (VLPs). To optimize VP2 gene expression in Sf9 cells, we converted wild-type VP2 (VP2) codons into codons that are more common in insect genes. This change greatly increased VP2 protein production in Sf9 cells. The protein generated from the codon-optimized VP2 (optVP2) was detected by immunoblotting and an indirect immunofluorescence assay (IFA). Transmission electron microscopy analysis revealed the formation of VLPs. These findings indicate that optVP2 yielded stable and high-quality VLPs. Immunogenicity assays revealed that the VLPs are highly immunogenic, elicit a high level of neutralizing antibodies and provide protection against lethal challenge. The antibody levels appeared to be directly related to the number of GP-Ag-positive hepatocytes. The variation trends for GP-Ag-positive hepatocytes were similar in the vaccine groups. In comparison with the control group, the optVP2 VLPs groups exhibited obviously better responses. These data indicate that the VLPs retained immunoreactivity and had strong immunogenicity in susceptible geese. Thus, GPV optVP2 appears to be a good candidate for the vaccination of goslings. Copyright © 2012 Elsevier B.V. All rights reserved.

T-cell dependent immunogenicity of protein therapeutics: Preclinical assessment and mitigation.

PubMed

Jawa, Vibha; Cousens, Leslie P; Awwad, Michel; Wakshull, Eric; Kropshofer, Harald; De Groot, Anne S

2013-12-01

Protein therapeutics hold a prominent and rapidly expanding place among medicinal products. Purified blood products, recombinant cytokines, growth factors, enzyme replacement factors, monoclonal antibodies, fusion proteins, and chimeric fusion proteins are all examples of therapeutic proteins that have been developed in the past few decades and approved for use in the treatment of human disease. Despite early belief that the fully human nature of these proteins would represent a significant advantage, adverse effects associated with immune responses to some biologic therapies have become a topic of some concern. As a result, drug developers are devising strategies to assess immune responses to protein therapeutics during both the preclinical and the clinical phases of development. While there are many factors that contribute to protein immunogenicity, T cell- (thymus-) dependent (Td) responses appear to play a critical role in the development of antibody responses to biologic therapeutics. A range of methodologies to predict and measure Td immune responses to protein drugs has been developed. This review will focus on the Td contribution to immunogenicity, summarizing current approaches for the prediction and measurement of T cell-dependent immune responses to protein biologics, discussing the advantages and limitations of these technologies, and suggesting a practical approach for assessing and mitigating Td immunogenicity. © 2013. Published by Elsevier Inc. All rights reserved.

[Paired kidneys in transplant].

PubMed

Regueiro López, Juan C; Leva Vallejo, Manuel; Prieto Castro, Rafael; Anglada Curado, Francisco; Vela Jiménez, Francisco; Ruiz García, Jesús

2009-02-01

Many factors affect the graft and patient survival on the renal transplant outcome. These factors depend so much of the recipient and donor. We accomplished a study trying to circumvent factors that depend on the donor. We checked the paired kidneys originating of a same donor cadaver. We examined the risk factors in the evolution and follow-up in 278 couples of kidney transplant. We describe their differences, significance, the graft and patient survival, their functionality in 3 and 5 years and the risk factors implicated in their function. We study immunogenic and no immunogenic variables, trying to explain the inferior results in the grafts that are established secondly. We regroup the paired kidneys in those that they did not show paired initial function within the same couple. The results yield a discreet deterioration in the graft and patient survival for second group establish, superior creatinina concentration, without obtaining statistical significance. The Cox regression study establishes the early rejection (inferior to three months) and DR incompatibility values like risk factors. This model of paired kidneys would be able to get close to best-suited form for risk factors analysis in kidney transplant from cadaver donors, if more patients examine themselves in the same way. The paired kidneys originating from the same donor do not show the same function in spite of sharing the same conditions of the donor and perioperative management.

Active and passive immunization for cancer.

PubMed

Baxter, David

2014-01-01

Vaccination started around the 10th century AD as a means of preventing smallpox. By the end of the 19th century such therapeutic vaccines were well established with both active and passive preparations being used in clinical practice. Active immunization involved administering an immunogen that might be live/ attenuated, killed/ inactivated, toxoid or subunit in origin. Passive immunization involved giving pre-formed antibodies, usually to very recently exposed individuals. At about the same time such approaches were also tried to treat a variety of cancers - proof of principle for the protective role of the immune response against malignancy was established by the observation that tumors transplanted into syngeneic hosts were rejected by the host innate and adaptive responses. The impact of these therapeutic vaccination has taken a considerable time to become established - in part because target antigens against which an adaptive response can be directed do not appear to be uniquely expressed on malignant transformed cells; and also because tumor cells are able to manipulate their environment to downregulate the host immune response. Therapeutic cancer vaccines are also divided into active and passive types - the latter being subdivided into specific and non-specific vaccines. Active immunization utilizes an immunogen to generate a host response designed to eliminate the malignant cells, whereas in passive immunization preformed antibodies or cells are administered to directly eliminate the transformed cells - examples of each are considered in this review.

Plant-expressed Fc-fusion protein tetravalent dengue vaccine with inherent adjuvant properties.

PubMed

Kim, Mi Young; Copland, Alastair; Nayak, Kaustuv; Chandele, Anmol; Ahmed, Muhammad S; Zhang, Qibo; Diogo, Gil R; Paul, Matthew J; Hofmann, Sven; Yang, Moon-Sik; Jang, Yong-Suk; Ma, Julian K-C; Reljic, Rajko

2017-12-09

Dengue is a major global disease requiring improved treatment and prevention strategies. The recently licensed Sanofi Pasteur Dengvaxia vaccine does not protect children under the age of nine, and additional vaccine strategies are thus needed to halt this expanding global epidemic. Here, we employed a molecular engineering approach and plant expression to produce a humanized and highly immunogenic poly-immunoglobulin G scaffold (PIGS) fused to the consensus dengue envelope protein III domain (cEDIII). The immunogenicity of this IgG Fc receptor-targeted vaccine candidate was demonstrated in transgenic mice expressing human FcγRI/CD64, by induction of neutralizing antibodies and evidence of cell-mediated immunity. Furthermore, these molecules were able to prime immune cells from human adenoid/tonsillar tissue ex vivo as evidenced by antigen-specific CD4 + and CD8 + T-cell proliferation, IFN-γ and antibody production. The purified polymeric fraction of dengue PIGS (D-PIGS) induced stronger immune activation than the monomeric form, suggesting a more efficient interaction with the low-affinity Fcγ receptors on antigen-presenting cells. These results show that the plant-expressed D-PIGS have the potential for translation towards a safe and easily scalable single antigen-based tetravalent dengue vaccine. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Genotype I of Japanese Encephalitis Virus Virus-like Particles Elicit Sterilizing Immunity against Genotype I and III Viral Challenge in Swine.

PubMed

Fan, Yi-Chin; Chen, Jo-Mei; Lin, Jen-Wei; Chen, Yi-Ying; Wu, Guan-Hong; Su, Kuan-Hsuan; Chiou, Ming-Tang; Wu, Shang-Rung; Yin, Ji-Hang; Liao, Jiunn-Wang; Chang, Gwong-Jen J; Chiou, Shyan-Song

2018-05-10

Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine.

Oral immunization with recombinant enterovirus 71 VP1 formulated with chitosan protects mice against lethal challenge

PubMed Central

2014-01-01

Background Enterovirus 71 (EV71) is the etiologic agent of hand-foot-and-mouth disease (HFMD) in the Asia-Pacific region, Many strategies have been applied to develop EV71 vaccines but no vaccines are currently available. Mucosal immunization of the VP1, a major immunogenic capsid protein of EV71, may be an alternative way to prevent EV71 infection. Results In this study, mucosal immunogenicity and protect function of recombinant VP1 protein (rVP1) in formulation with chitosan were tested and assessed in female ICR mouse model. The results showed that the oral immunization with rVP1 induced VP1-specific IgA antibodies in intestine, feces, vagina, and the respiratory tract and serum-specific IgG and neutralization antibodies in vaccinated mice. Splenocytes from rVP1-immunized mice induced high levels of Th1 (cytokine IFN-γ), Th2 (cytokine IL-4) and Th3 (cytokine TGF-β) type immune responses after stimulation. Moreover, rVP1-immunized mother mice conferred protection (survival rate up to 30%) on neonatal mice against a lethal challenge of 103 plaque-forming units (PFU) EV71. Conclusions These data indicated that oral immunization with rVP1 in formulation with chitosan was effective in inducing broad-spectrum immune responses and might be a promising subunit vaccine candidate for preventing EV71 infection. PMID:24885121

Tetravalent dengue DIIIC protein together with alum and ODN elicits a Th1 response and neutralizing antibodies in mice.

PubMed

Zuest, Roland; Valdes, Iris; Skibinski, David; Lin, Yufang; Toh, Ying Xiu; Chan, Katherine; Hermida, Lisset; Connolly, John; Guillen, Gerardo; Fink, Katja

2015-03-17

Dengue disease is a global challenge for healthcare systems particularly during outbreaks, and millions of dollars are spent every year for vector control. An efficient and safe vaccine that is cost-effective could resolve the burden that dengue virus imposes on affected countries. We describe here the immunogenicity of a tetravalent formulation of a recombinant fusion protein consisting of E domain III and the capsid protein of dengue serotypes 1-4 (Tetra DIIIC). E domain III is an epitope for efficient neutralizing antibodies while the capsid protein contains T cell epitopes. Besides combining B and T cell epitopes, Tetra DIIIC is highly immunogenic due to its aggregate form and a two-component adjuvant. Following previous studies assessing the monovalent DIIIC formulations, we addressed here the quality and breadth of the T cell- and antibody response of Tetra DIIIC in mice. Tetra DIIIC induced a Th1-type response against all four DENV serotypes and dengue-specific antibodies were predominantly IgG1 and IgG2a and neutralizing, while the induction of neutralizing antibodies was dependent on IFN signaling. Importantly, the Th1 and IgG1/IgG2a profile of the DIIIC vaccine approach is similar to an efficient natural anti-dengue response. Copyright © 2015 Elsevier Ltd. All rights reserved.

Active and passive immunization for cancer

PubMed Central

Baxter, David

2014-01-01

Vaccination started around the 10th century AD as a means of preventing smallpox. By the end of the 19th century such therapeutic vaccines were well established with both active and passive preparations being used in clinical practice. Active immunization involved administering an immunogen that might be live/ attenuated, killed/ inactivated, toxoid or subunit in origin. Passive immunization involved giving pre-formed antibodies, usually to very recently exposed individuals. At about the same time such approaches were also tried to treat a variety of cancers – proof of principle for the protective role of the immune response against malignancy was established by the observation that tumors transplanted into syngeneic hosts were rejected by the host innate and adaptive responses. The impact of these therapeutic vaccination has taken a considerable time to become established - in part because target antigens against which an adaptive response can be directed do not appear to be uniquely expressed on malignant transformed cells; and also because tumor cells are able to manipulate their environment to downregulate the host immune response. Therapeutic cancer vaccines are also divided into active and passive types – the latter being subdivided into specific and non-specific vaccines. Active immunization utilizes an immunogen to generate a host response designed to eliminate the malignant cells, whereas in passive immunization preformed antibodies or cells are administered to directly eliminate the transformed cells - examples of each are considered in this review. PMID:25424829

Detection of the Assembly and Disassembly of PCV2b Virus-Like Particles Using Fluorescence Spectroscopy Analysis.

PubMed

Fang, Mingli; Diao, Wenzhen; Dong, Boqi; Wei, Hongfei; Liu, Jialin; Hua, Li; Zhang, Miaomin; Guo, Sheng; Xiao, Yue; Yu, Yongli; Wang, Liying; Wan, Min

2015-01-01

Monitoring the assembly and disassembly of virus-like particles (VLPs) is important in developing effective VLP-based vaccines. We tried to establish a simple and rapid method to evaluate the status of VLP assembly using fluorescence spectroscopic analysis (FSA) while developing a VLP-based vaccine against porcine circovirus type 2b (PCV2b). We synthesized the gene coding for PCV2b capsid protein (CP). The CP was expressed in Escherichia coli in a soluble form, dialyzed into three different buffers, and assembled into VLPs. The immunogenicity of the VLPs was evaluated by an enzyme-linked immunosorbent assay using the sera of mice immunized with inactivated PCV2b. The VLP assembly was detected using transmission electron microscopy and FSA. The assembled VLPs showed a distinct FSA curve with a peak at 320 nm. We found that the assembly status was related to the immunogenicity, fluorescence intensity, and morphology of the VLP. The FSA assay was able to monitor the various denatured statuses of PCV2b VLPs treated with β-mercaptoethanol or β-mercaptoethanol plus urea. We have demonstrated that FSA can be used to detect the assembly of PCV2b VLPs produced in E. coli. This provides a simple solution for monitoring VLP assembly during the production of VLP-based vaccines. © 2016 S. Karger AG, Basel.

Modified Newcastle Disease virus as an improved vaccine vector against Simian Immunodeficiency virus.

PubMed

Manoharan, Vinoth K; Khattar, Sunil K; LaBranche, Celia C; Montefiori, David C; Samal, Siba K

2018-06-12

SIV infection in macaques is a relevant animal model for HIV pathogenesis and vaccine study in humans. To design a safe and effective vaccine against HIV, we evaluated the suitability of naturally-occurring avirulent Newcastle disease virus (NDV) strains and several modified versions of NDV as vectors for the expression and immunogenicity of SIV envelope protein gp160. All the NDV vectors expressed gp160 protein in infected cells. The gp160 expressed by these vectors formed oligomers and was incorporated into the NDV envelope. All the NDV vectors expressing gp160 were attenuated in chickens. Intranasal immunization of guinea pigs with modified NDV vectors such as rNDV-APMV-2CS/gp160 and rNDV-APMV-8CS/gp160 (NDV strain LaSota containing the cleavage site sequences of F protein of avian paramyxovirus (APMV) serotype 2 and 8, respectively), and rNDV-BC-F-HN/gp160 (NDV strain BC containing LaSota F cleavage site and LaSota F and HN genes) elicited improved SIV-specific humoral and mucosal immune responses compared to other NDV vectors. These modified vectors were also efficient in inducing neutralizing antibody responses to tier 1 A SIVmac251.6 and tier 1B SIVmac251/M766 strains. This study suggests that our novel modified NDV vectors are safe and immunogenic and can be used as vaccine vector to control HIV.

An immunosurveillance mechanism controls cancer cell ploidy.

PubMed

Senovilla, Laura; Vitale, Ilio; Martins, Isabelle; Tailler, Maximilien; Pailleret, Claire; Michaud, Mickaël; Galluzzi, Lorenzo; Adjemian, Sandy; Kepp, Oliver; Niso-Santano, Mireia; Shen, Shensi; Mariño, Guillermo; Criollo, Alfredo; Boilève, Alice; Job, Bastien; Ladoire, Sylvain; Ghiringhelli, François; Sistigu, Antonella; Yamazaki, Takahiro; Rello-Varona, Santiago; Locher, Clara; Poirier-Colame, Vichnou; Talbot, Monique; Valent, Alexander; Berardinelli, Francesco; Antoccia, Antonio; Ciccosanti, Fabiola; Fimia, Gian Maria; Piacentini, Mauro; Fueyo, Antonio; Messina, Nicole L; Li, Ming; Chan, Christopher J; Sigl, Verena; Pourcher, Guillaume; Ruckenstuhl, Christoph; Carmona-Gutierrez, Didac; Lazar, Vladimir; Penninger, Josef M; Madeo, Frank; López-Otín, Carlos; Smyth, Mark J; Zitvogel, Laurence; Castedo, Maria; Kroemer, Guido

2012-09-28

Cancer cells accommodate multiple genetic and epigenetic alterations that initially activate intrinsic (cell-autonomous) and extrinsic (immune-mediated) oncosuppressive mechanisms. Only once these barriers to oncogenesis have been overcome can malignant growth proceed unrestrained. Tetraploidization can contribute to oncogenesis because hyperploid cells are genomically unstable. We report that hyperploid cancer cells become immunogenic because of a constitutive endoplasmic reticulum stress response resulting in the aberrant cell surface exposure of calreticulin. Hyperploid, calreticulin-exposing cancer cells readily proliferated in immunodeficient mice and conserved their increased DNA content. In contrast, hyperploid cells injected into immunocompetent mice generated tumors only after a delay, and such tumors exhibited reduced DNA content, endoplasmic reticulum stress, and calreticulin exposure. Our results unveil an immunosurveillance system that imposes immunoselection against hyperploidy in carcinogen- and oncogene-induced cancers.