Linearized hepatitis B surface antigen and hepatitis B core-related antigen in the natural history of chronic hepatitis B.

PubMed

Seto, W-K; Wong, D K-H; Fung, J; Huang, F-Y; Liu, K S-H; Lai, C-L; Yuen, M-F

2014-11-01

Changes in two novel HBV serological markers, linearized hepatitis B surface antigen (HQ-HBsAg) and hepatitis B core-related antigen (HBcrAg), in the natural history of chronic hepatitis B (CHB) have not been well characterized. Serum HQ-HBsAg and HBcrAg levels of 404 Asian treatment-naïve CHB patients were analysed in a cross-sectional manner. Patients were categorized into five groups: immune tolerant (IT group, n=52), immune clearance (IC group, n=105), hepatitis B e antigen (HBeAg)-negative hepatitis (ENH group, n=97), HBeAg-negative quiescent group (ENQ group, n=95) and CHB with hepatitis B surface antigen (HBsAg) seroclearance (SC group, n=55). HQ-HBsAg and HBcrAg were measured and correlated with HBV DNA, HBsAg, HBV genotype and clinical parameters. HQ-HBsAg showed good correlation with HBsAg, especially in the ENQ group (r=0.874, p<0.001). Correlation of HQ-HBsAg with HBV DNA was less prominent and weakest in the ENH group (r=0.268, p 0.008). HBcrAg correlated best with HBV DNA in the ENQ group (r=0.537, p<0.001). In the ENQ group, 42.1% of patients had undetectable HBcrAg; this subgroup of patients, when compared with those with detectable HBcrAg, had significantly lower median HBV DNA (3.17/4.48 log IU/mL, p<0.001) and HBsAg (5.05/5.96 log mIU/mL, p<0.001) levels. Forty per cent of the SC group patients had detectable HQ-HBsAg and/or HBcrAg up to 42 months after HBsAg seroclearance. When comparing anti-HBs positivity and median time after HBsAg seroclearance in the SC group with and without detectable HQ-HBsAg/HBcrAg, there was no significant difference (22.7% and 36.4%, respectively, p 0.284, and 76.5 and 93.2 months, respectively, p 0.245). HQ-HBsAg and HBcrAg showed unique patterns of distribution throughout the five disease phases of CHB, including high detectability rates after HBsAg seroclearance, opening up different possibilities for their applicability. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical

Oral immunization with hepatitis B surface antigen expressed in transgenic plants

PubMed Central

Kong, Qingxian; Richter, Liz; Yang, Yu Fang; Arntzen, Charles J.; Mason, Hugh S.; Thanavala, Yasmin

2001-01-01

Oral immunogenicity of recombinant hepatitis B surface antigen (HBsAg) derived from yeast (purified product) or in transgenic potatoes (uncooked unprocessed sample) was compared. An oral adjuvant, cholera toxin, was used to increase immune responses. Transgenic plant material containing HBsAg was the superior means of both inducing a primary immune response and priming the mice to respond to a subsequent parenteral injection of HBsAg. Electron microscopy of transgenic plant samples revealed evidence that the HBsAg accumulated intracellularly; we conclude that natural bioencapsulation of the antigen may provide protection from degradation in the digestive tract until plant cell degradation occurs near an immune effector site in the gut. The correlate of protection from hepatitis B virus infection is serum antibody titers induced by vaccination; the protective level in humans is 10 milliunits/ml or greater. Mice fed HBsAg-transgenic potatoes produced HBsAg-specific serum antibodies that exceeded the protective level and, on parenteral boosting, generated a strong long-lasting secondary antibody response. We have also shown the effectiveness of oral delivery by using a parenteral prime-oral boost immunization schedule. The demonstrated success of oral immunization for hepatitis B virus with an “edible vaccine” provides a strategy for contributing a means to achieve global immunization for hepatitis B prevention and eradication. PMID:11553782

Heterosubtypic Neutralizing Monoclonal Antibodies Cross-Protective against H5N1 and H1N1 Recovered from Human IgM+ Memory B Cells

PubMed Central

Throsby, Mark; van den Brink, Edward; Jongeneelen, Mandy; Poon, Leo L. M.; Alard, Philippe; Cornelissen, Lisette; Bakker, Arjen; Cox, Freek; van Deventer, Els; Guan, Yi; Cinatl, Jindrich; ter Meulen, Jan; Lasters, Ignace; Carsetti, Rita; Peiris, Malik; de Kruif, John; Goudsmit, Jaap

2008-01-01

Background The hemagglutinin (HA) glycoprotein is the principal target of protective humoral immune responses to influenza virus infections but such antibody responses only provide efficient protection against a narrow spectrum of HA antigenic variants within a given virus subtype. Avian influenza viruses such as H5N1 are currently panzootic and pose a pandemic threat. These viruses are antigenically diverse and protective strategies need to cross protect against diverse viral clades. Furthermore, there are 16 different HA subtypes and no certainty the next pandemic will be caused by an H5 subtype, thus it is important to develop prophylactic and therapeutic interventions that provide heterosubtypic protection. Methods and Findings Here we describe a panel of 13 monoclonal antibodies (mAbs) recovered from combinatorial display libraries that were constructed from human IgM+ memory B cells of recent (seasonal) influenza vaccinees. The mAbs have broad heterosubtypic neutralizing activity against antigenically diverse H1, H2, H5, H6, H8 and H9 influenza subtypes. Restriction to variable heavy chain gene IGHV1-69 in the high affinity mAb panel was associated with binding to a conserved hydrophobic pocket in the stem domain of HA. The most potent antibody (CR6261) was protective in mice when given before and after lethal H5N1 or H1N1 challenge. Conclusions The human monoclonal CR6261 described in this study could be developed for use as a broad spectrum agent for prophylaxis or treatment of human or avian influenza infections without prior strain characterization. Moreover, the CR6261 epitope could be applied in targeted vaccine strategies or in the design of novel antivirals. Finally our approach of screening the IgM+ memory repertoire could be applied to identify conserved and functionally relevant targets on other rapidly evolving pathogens. PMID:19079604

Covalent binding of C3b to tetanus toxin: influence on uptake/internalization of antigen by antigen-specific and non-specific B cells.

PubMed Central

Villiers, M B; Villiers, C L; Jacquier-Sarlin, M R; Gabert, F M; Journet, A M; Colomb, M G

1996-01-01

Antigen opsonization by the C3b fragment of complement is a significant event in the modulation of cell-mediated immune response, but its mechanism is still largely unknown. The structural characteristics of C3b allow it to act as a bifunctional ligand between antigen and cells via their membrane C3b receptors. It was thus of interest to study the influence of the covalent link between C3b and antigen on the fixation and internalization of this antigen by antigen-presenting cells. Tetanus toxin (TT) was used as antigen, either free or covalently linked to C3b (TT-C3b). The antigen-presenting cells were TT-specific (4.2) or non-specific (BL15) Epstein-Barr virus (EBV)-transformed B cells. C3b was found to play an important role in antigen fixation and internalization by both antigen-specific and antigen non-specific cells. Covalent binding of C3b on TT (1) permitted fixation and internalization of this antigen by non-specific cells via their complement receptors; (2) enhanced antigen fixation and resulted in cross-linking between membrane immunoglobulins and complement receptors on antigen-specific cells. The consequences of covalent C3b binding to TT were analysed using antigen-specific and antigen-nonspecific cells. In both cases, a net increase in antigen fixation was observed. At the intracellular level, covalent C3b binding to TT resulted in a large TT incorporation in endosomes of nonspecific cells, similar to that observed in antigen-specific cells. Thus, C3b covalently linked to antigen enlarges the array of B-cell types capable of presenting antigen, including non-specific cells. Images Figure 2 PMID:8958046

Immunogenicity and Protection Efficacy of Subunit-based Smallpox Vaccines Using Variola Major Antigens

PubMed Central

Sakhatskyy, Pavlo; Wang, Shixia; Zhang, Chuanyou; Chou, Te-Hui; Kishko, Michael; Lu, Shan

2008-01-01

The viral strain responsible for smallpox infection is variola major (VARV). As a result of the successful eradication of smallpox with the vaccinia virus (VACV), the general population is no longer required to receive a smallpox vaccine, and will have no protection against smallpox. This lack of immunity is a concern due to the potential for use of smallpox as a biological weapon. Considerable progress has been made in the development of subunit-based smallpox vaccines resulting from the identification of VACV protective antigens. It also offers the possibility of using antigens from VARV to formulate the next generation subunit-based smallpox vaccines. Here, we show that codon-optimized DNA vaccines expressing three VARV antigens (A30, B7 and F8) and their recombinant protein counterparts elicited high-titer, cross-reactive, VACV neutralizing antibody responses in mice. Vaccinated mice were protected from intraperitoneal and intranasal challenges with VACV. These results suggest the feasibility of a subunit smallpox vaccine based on the VARV antigen sequences to induce immunity against poxvirus infection. PMID:17950773

Immunogenicity and protection efficacy of subunit-based smallpox vaccines using variola major antigens.

PubMed

Sakhatskyy, Pavlo; Wang, Shixia; Zhang, Chuanyou; Chou, Te-Hui; Kishko, Michael; Lu, Shan

2008-02-05

The viral strain responsible for smallpox infection is variola major (VARV). As a result of the successful eradication of smallpox with the vaccinia virus (VACV), the general population is no longer required to receive a smallpox vaccine, and will have no protection against smallpox. This lack of immunity is a concern due to the potential for use of smallpox as a biological weapon. Considerable progress has been made in the development of subunit-based smallpox vaccines resulting from the identification of VACV protective antigens. It also offers the possibility of using antigens from VARV to formulate the next generation subunit-based smallpox vaccines. Here, we show that codon-optimized DNA vaccines expressing three VARV antigens (A30, B7 and F8) and their recombinant protein counterparts elicited high-titer, cross-reactive, VACV neutralizing antibody responses in mice. Vaccinated mice were protected from intraperitoneal and intranasal challenges with VACV. These results suggest the feasibility of a subunit smallpox vaccine based on VARV antigen sequences to induce immunity against poxvirus infection.

Potentiation of anthrax vaccines using protective antigen-expressing viral replicon vectors.

PubMed

Wang, Hai-Chao; An, Huai-Jie; Yu, Yun-Zhou; Xu, Qing

2015-02-01

DNA vaccines require improvement for human use because they are generally weak stimulators of the immune system in humans. The efficacy of DNA vaccines can be improved using a viral replicon as vector to administer antigen of pathogen. In this study, we comprehensively evaluated the conventional non-viral DNA, viral replicon DNA or viral replicon particles (VRP) vaccines encoding different forms of anthrax protective antigen (PA) for specific immunity and protective potency against anthrax. Our current results clearly suggested that these viral replicon DNA or VRP vaccines derived from Semliki Forest virus (SFV) induced stronger PA-specific immune responses than the conventional non-viral DNA vaccines when encoding the same antigen forms, which resulted in potent protection against challenge with the Bacillus anthracis strain A16R. Additionally, the naked PA-expressing SFV replicon DNA or VRP vaccines without the need for high doses or demanding particular delivery regimens elicited robust immune responses and afforded completely protective potencies, which indicated the potential of the SFV replicon as vector of anthrax vaccines for use in clinical application. Therefore, our results suggest that these PA-expressing SFV replicon DNA or VRP vaccines may be suitable as candidate vaccines against anthrax. Copyright © 2015 Elsevier B.V. All rights reserved.

Genetic Mapping Identifies Novel Highly Protective Antigens for an Apicomplexan Parasite

PubMed Central

Blake, Damer P.; Billington, Karen J.; Copestake, Susan L.; Oakes, Richard D.; Quail, Michael A.; Wan, Kiew-Lian; Shirley, Martin W.; Smith, Adrian L.

2011-01-01

Apicomplexan parasites are responsible for a myriad of diseases in humans and livestock; yet despite intensive effort, development of effective sub-unit vaccines remains a long-term goal. Antigenic complexity and our inability to identify protective antigens from the pool that induce response are serious challenges in the development of new vaccines. Using a combination of parasite genetics and selective barriers with population-based genetic fingerprinting, we have identified that immunity against the most important apicomplexan parasite of livestock (Eimeria spp.) was targeted against a few discrete regions of the genome. Herein we report the identification of six genomic regions and, within two of those loci, the identification of true protective antigens that confer immunity as sub-unit vaccines. The first of these is an Eimeria maxima homologue of apical membrane antigen-1 (AMA-1) and the second is a previously uncharacterised gene that we have termed ‘immune mapped protein-1’ (IMP-1). Significantly, homologues of the AMA-1 antigen are protective with a range of apicomplexan parasites including Plasmodium spp., which suggest that there may be some characteristic(s) of protective antigens shared across this diverse group of parasites. Interestingly, homologues of the IMP-1 antigen, which is protective against E. maxima infection, can be identified in Toxoplasma gondii and Neospora caninum. Overall, this study documents the discovery of novel protective antigens using a population-based genetic mapping approach allied with a protection-based screen of candidate genes. The identification of AMA-1 and IMP-1 represents a substantial step towards development of an effective anti-eimerian sub-unit vaccine and raises the possibility of identification of novel antigens for other apicomplexan parasites. Moreover, validation of the parasite genetics approach to identify effective antigens supports its adoption in other parasite systems where legitimate protective

B-cell acquisition of antigen: Sensing the surface.

PubMed

Knight, Andrew M

2015-06-01

B-cell antigen receptor (BCR) recognition and acquisition of antigen by B cells is the essential first step in the generation of effective antibody responses. As B-cell-mediated antigen presentation is also believed to play a significant role in the activation of CD4(+) Th-cell responses, considerable effort has focused on clarifying the nature of antigen/BCR interactions. Following earlier descriptions of interactions of soluble antigens with the BCR, it is now clear that B cells also recognize, physically extract and present antigens that are tethered to, or integral components of, the surfaces or extracellular matrix of other cells. In this issue of the European Journal of Immunology, Zeng et al. [Eur. J. Immunol. 2015. 45: XXXX-XXXX] examine how the physical property or "stiffness" of the surface displaying antigens to B cells influences the B-cell response. This commentary reports that antigen tethered on "less stiff" surfaces induces increased B-cell activation and antibody responses. I then infer how "sensing the surface" by B cells may represent a new component of the immune system's ability to detect "damage," and how this understanding may influence approaches to clinical therapies where immune activity is either unwanted or desired. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intranasal Immunization with Influenza Virus-Like Particles Containing Membrane-Anchored Cholera Toxin B or Ricin Toxin B Enhances Adaptive Immune Responses and Protection against an Antigenically Distinct Virus.

PubMed

Ji, Xianliang; Ren, Zhiguang; Xu, Na; Meng, Lingnan; Yu, Zhijun; Feng, Na; Sang, Xiaoyu; Li, Shengnan; Li, Yuanguo; Wang, Tiecheng; Zhao, Yongkun; Wang, Hualei; Zheng, Xuexing; Jin, Hongli; Li, Nan; Yang, Songtao; Cao, Jinshan; Liu, Wensen; Gao, Yuwei; Xia, Xianzhu

2016-04-21

Vaccination is the most effective means to prevent influenza virus infection, although current approaches are associated with suboptimal efficacy. Here, we generated virus-like particles (VLPs) composed of the hemagglutinin (HA), neuraminidase (NA) and matrix protein (M1) of A/Changchun/01/2009 (H1N1) with or without either membrane-anchored cholera toxin B (CTB) or ricin toxin B (RTB) as molecular adjuvants. The intranasal immunization of mice with VLPs containing membrane-anchored CTB or RTB elicited stronger humoral and cellular immune responses when compared to mice immunized with VLPs alone. Administration of VLPs containing CTB or RTB significantly enhanced virus-specific systemic and mucosal antibody responses, hemagglutination inhibiting antibody titers, virus neutralizing antibody titers, and the frequency of virus-specific IFN-γ and IL-4 secreting splenocytes. VLPs with and without CTB or RTB conferred complete protection against lethal challenge with a mouse-adapted homologous virus. When challenged with an antigenically distinct H1N1 virus, all mice immunized with VLPs containing CTB or RTB survived whereas mice immunized with VLPs alone showed only partial protection (80% survival). Our results suggest that membrane-anchored CTB and RTB possess strong adjuvant properties when incorporated into an intranasally-delivered influenza VLP vaccine. Chimeric influenza VLPs containing CTB or RTB may represent promising vaccine candidates for improved immunological protection against homologous and antigenically distinct influenza viruses.

Intranasal Immunization with Influenza Virus-Like Particles Containing Membrane-Anchored Cholera Toxin B or Ricin Toxin B Enhances Adaptive Immune Responses and Protection against an Antigenically Distinct Virus

PubMed Central

Ji, Xianliang; Ren, Zhiguang; Xu, Na; Meng, Lingnan; Yu, Zhijun; Feng, Na; Sang, Xiaoyu; Li, Shengnan; Li, Yuanguo; Wang, Tiecheng; Zhao, Yongkun; Wang, Hualei; Zheng, Xuexing; Jin, Hongli; Li, Nan; Yang, Songtao; Cao, Jinshan; Liu, Wensen; Gao, Yuwei; Xia, Xianzhu

2016-01-01

Vaccination is the most effective means to prevent influenza virus infection, although current approaches are associated with suboptimal efficacy. Here, we generated virus-like particles (VLPs) composed of the hemagglutinin (HA), neuraminidase (NA) and matrix protein (M1) of A/Changchun/01/2009 (H1N1) with or without either membrane-anchored cholera toxin B (CTB) or ricin toxin B (RTB) as molecular adjuvants. The intranasal immunization of mice with VLPs containing membrane-anchored CTB or RTB elicited stronger humoral and cellular immune responses when compared to mice immunized with VLPs alone. Administration of VLPs containing CTB or RTB significantly enhanced virus-specific systemic and mucosal antibody responses, hemagglutination inhibiting antibody titers, virus neutralizing antibody titers, and the frequency of virus-specific IFN-γ and IL-4 secreting splenocytes. VLPs with and without CTB or RTB conferred complete protection against lethal challenge with a mouse-adapted homologous virus. When challenged with an antigenically distinct H1N1 virus, all mice immunized with VLPs containing CTB or RTB survived whereas mice immunized with VLPs alone showed only partial protection (80% survival). Our results suggest that membrane-anchored CTB and RTB possess strong adjuvant properties when incorporated into an intranasally-delivered influenza VLP vaccine. Chimeric influenza VLPs containing CTB or RTB may represent promising vaccine candidates for improved immunological protection against homologous and antigenically distinct influenza viruses. PMID:27110810

Intramuscular delivery of adenovirus serotype 5 vector expressing humanized protective antigen induces rapid protection against anthrax that may bypass intranasally originated preexisting adenovirus immunity.

PubMed

Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie; Hou, Lihua; Chen, Wei

2014-02-01

Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 10⁸ infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD₅₀) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax.

Intramuscular Delivery of Adenovirus Serotype 5 Vector Expressing Humanized Protective Antigen Induces Rapid Protection against Anthrax That May Bypass Intranasally Originated Preexisting Adenovirus Immunity

PubMed Central

Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie

2014-01-01

Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 108 infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD50) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax. PMID:24307239

Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex.

PubMed Central

Brake, D A; Fedor, C H; Werner, B W; Miller, T J; Taylor, R L; Clare, R A

1997-01-01

A model to simulate natural immunity to Eimeria tenella was developed in three chicken lines which differ at the B locus of the major histocompatibility complex. Homozygous, 1-day-old chicks of the B19B19, B24B24, or B30B30 genotype were trickle immunized by being orally fed a small infectious dose of E. tenella oocysts for 5 consecutive days. These naturally exposed birds were then challenged at different times between 5 and 24 days after the final dose, and the level of protection was assessed 6 days after challenge, using body weight gain and intestinal lesion scores. The duration of immunity in naturally exposed birds differed among the major histocompatibility complex lines. Trickle immunization of the B19B19 haplotype afforded the longest and strongest level of protection compared to the other two haplotypes tested. In addition, in vitro splenic and peripheral blood lymphocyte proliferative responses in trickle-immunized birds were measured against sporozoite, merozoite, and tissue culture-derived E. tenella parasite antigens isolated from the recently described SB-CEV-1/F7 established cell line. The lymphocytes obtained from B19B19 birds trickle immunized responded in vitro to the E. tenella-infected SB-CEV-1/F7 tissue culture-derived parasite antigen. Furthermore, antigen-specific immune responses appeared earlier in immune, challenged B19B19 birds than in their naive, challenged counterparts. The development of a model simulating natural immunization will serve as a foundation to further characterize both humoral and cell-mediated responses to E. tenella tissue culture-derived parasite antigens and to better understand host protective immune responses to avian coccidiosis. PMID:9119452

A plant-produced protective antigen vaccine confers protection in rabbits against a lethal aerosolized challenge with Bacillus anthracis Ames spores.

PubMed

Chichester, Jessica A; Manceva, Slobodanka D; Rhee, Amy; Coffin, Megan V; Musiychuk, Konstantin; Mett, Vadim; Shamloul, Moneim; Norikane, Joey; Streatfield, Stephen J; Yusibov, Vidadi

2013-03-01

The potential use of Bacillus anthracis as a bioterrorism weapon threatens the security of populations globally, requiring the immediate availability of safe, efficient and easily delivered anthrax vaccine for mass vaccination. Extensive research efforts have been directed toward the development of recombinant subunit vaccines based on protective antigen (PA), the principal virulence factor of B. anthracis. Among the emerging technologies for the production of these vaccine antigens is our launch vector-based plant transient expression system. Using this system, we have successfully engineered, expressed, purified and characterized full-length PA (pp-PA83) in Nicotiana benthamiana plants using agroinfiltration. This plant-produced antigen elicited high toxin neutralizing antibody titers in mice and rabbits after two vaccine administrations with Alhydrogel. In addition, immunization with this vaccine candidate protected 100% of rabbits from a lethal aerosolized B. anthracis challenge. The vaccine effects were dose-dependent and required the presence of Alhydrogel adjuvant. In addition, the vaccine antigen formulated with Alhydrogel was stable and retained immunogenicity after two-week storage at 4°C, the conditions intended for clinical use. These results support the testing of this vaccine candidate in human volunteers and the utility of our plant expression system for the production of a recombinant anthrax vaccine.

21 CFR 660.40 - Hepatitis B Surface Antigen.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

21 CFR 660.40 - Hepatitis B Surface Antigen.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

21 CFR 660.40 - Hepatitis B Surface Antigen.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

21 CFR 660.40 - Hepatitis B Surface Antigen.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

21 CFR 660.40 - Hepatitis B Surface Antigen.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Hepatitis B Surface Antigen. 660.40 Section 660.40...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.40 Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product...

Intradermal delivery of Shigella IpaB and IpaD type III secretion proteins: Kinetics of cell recruitment and antigen uptake, mucosal and systemic immunity, and protection across serotypes

PubMed Central

Heine, Shannon J.; Diaz-McNair, Jovita; Andar, Abhay U.; Drachenberg, Cinthia B.; van de Verg, Lillian; Walker, Richard; Picking, Wendy L.; Pasetti, Marcela F.

2014-01-01

Shigella is one of the leading pathogens contributing to the vast pediatric diarrheal disease burden in low-income countries. No licensed vaccine is available and the existing candidates are only partially effective and serotype-specific. Shigella type III secretion system proteins IpaB and IpaD, which are conserved across Shigella spp., are candidates for a broadly protective, subunit-based vaccine. Herein, we investigated the immunogenicity and protective efficacy of IpaB and IpaD administered intradermally (i.d.) with a double-mutant of the E. coli heat-labile enterotoxin (dmLT) adjuvant using microneedles. Different dosage levels of IpaB and IpaD with or without dmLT were tested in mice. Vaccine delivery into the dermis, recruitment of neutrophils, macrophages, dendritic cells (DC) and Langerhans cells (LC), and colocalization of vaccine antigens within skin-activated antigen presenting cells (APC) was demonstrated through histology and immunofluorescence microscopy. Ag-loaded neutrophils, macrophages, DC and LC remained in the tissue at least one week. IpaB, IpaD and dmLT-specific serum IgG and IgG secreting cells were produced following i.d. immunization. The protective efficacy was 70% against S. flexneri and 50% against S. sonnei. Similar results were obtained when the vaccine was administered intranasally, with the i.d. route requiring 25-40 times lower doses. Distinctively, IgG was detected in mucosal secretions; sIgA as well as mucosal and systemic IgA antibody secreting cells (ASC) were seemingly absent. Vaccine-induced T cells produced IFN-γ, IL-2, TNF-α, IL-17, IL-4, IL-5 and IL-10. These results demonstrate the potential of i.d. vaccination with IpaB and IpaD to prevent Shigella infection and support further studies in humans. PMID:24453241

Galactose-1-phosphate uridyltransferase (GalT), an in vivo-induced antigen of Actinobacillus pleuropneumoniae serovar 5b strain L20, provided immunoprotection against serovar 1 strain MS71.

PubMed

Zhang, Fei; Zhao, Qin; Quan, Keji; Zhu, Zhuang; Yang, Yusheng; Wen, Xintian; Chang, Yung-Fu; Huang, Xiaobo; Wu, Rui; Wen, Yiping; Yan, Qigui; Huang, Yong; Ma, Xiaoping; Han, Xinfeng; Cao, Sanjie

2018-01-01

GALT is an important antigen of Actinobacillus pleuropneumoniae (APP), which was shown to provide partial protection against APP infection in a previous study in our lab. The main purpose of the present study is to investigate GALT induced cross-protection between different APP serotypes and elucidate key mechanisms of the immune response to GALT antigenic stimulation. Bioinformatic analysis demonstrated that galT is a highly conserved gene in APP, widely distributed across multiple pathogenic strains. Homologies between any two strains ranges from 78.9% to 100% regarding the galT locus. Indirect enzyme-linked immunosorbent assay (ELISA) confirmed that GALT specific antibodies could not be induced by inactivated APP L20 or MS71 whole cell bacterin preparations. A recombinant fusion GALT protein derived from APP L20, however has proven to be an effective cross-protective antigen against APP sevorar 1 MS71 (50%, 4/8) and APP sevorar 5b L20 (75%, 6/8). Histopathological examinations have confirmed that recombinant GALT vaccinated animals showed less severe pathological signs in lung tissues than negative controls after APP challenge. Immunohistochemical (IHC) analysis indicated that the infiltration of neutrophils in the negative group is significantly increased compared with that in the normal control (P<0.001) and that in surviving animals is decreased compared to the negative group. Anti-GALT antibodies were shown to mediate phagocytosis of neutrophils. After interaction with anti-GALT antibodies, survival rate of APP challenged vaccinated animals was significantly reduced (P<0.001). This study demonstrated that GALT is an effective cross-protective antigen, which could be used as a potential vaccine candidate against multiple APP serotypes.

Studies of the conformational stability of invasion plasmid antigen B from Shigella

PubMed Central

Choudhari, Shyamal P; Kramer, Ryan; Barta, Michael L; Greenwood, Jamie C; Geisbrecht, Brian V; Joshi, Sangeeta B; Picking, William D; Middaugh, C Russell; Picking, Wendy L

2013-01-01

Shigella spp. are the causative agent of shigellosis, the second leading cause of diarrhea in children of ages 2–5. Despite many years of research, a protective vaccine has been elusive. We recently demonstrated that invasion plasmid antigens B and D (IpaB and IpaD) provide protection against S. flexneri and S. sonnei. These proteins, however, have very different properties which must be recognized and then managed during vaccine formulation. Herein, we employ spectroscopy to assess the stability of IpaB as well as IpgC (invasion protein gene), IpaB's cognate chaperone, and the IpaB/IpgC complex. The resulting data are mathematically summarized into a visual map illustrating the stability of the proteins and their complex as a function of pH and temperature. The IpaB/IpgC complex exhibits thermal stability at higher pH values but, though initially stable, quickly unfolds with increasing temperature when maintained at lower pH. In contrast, IpaB is a much more complex protein exhibiting increased stability at higher pH, but shows initial instability at lower pH values with pH 5 showing a distinct transition. IpgC precipitates at and below pH 5 and is stable above pH 7. Most strikingly, it is clear that complex formation results in stabilization of the two components. This work serves as a basis for the further development of IpaB as a vaccine candidate as well as extends our understanding of the structural stability of the Shigella type III secretion system. PMID:23494968

Enhanced acquired antibodies to a chimeric Plasmodium falciparum antigen; UB05-09 is associated with protective immunity against malaria.

PubMed

Dinga, J N; Gamua, S D; Titanji, V P K

2017-08-01

It has been shown that covalently linking two antigens could enhance the immunogenicity of the chimeric construct. To prioritize such a chimera for malaria vaccine development, it is necessary to demonstrate that naturally acquired antibodies against the chimera are associated with protection from malaria. Here, we probe the ability of a chimeric construct of UB05 and UB09 antigens (UB05-09) to better differentiate between acquired immune protection and susceptibility to malaria. In a cross-sectional study, recombinant UB05-09 chimera and the constituent antigens were used to probe for specific antibodies in the plasma from children and adults resident in a malaria-endemic zone, using the enzyme-linked immunosorbent assay (ELISA). Anti-UB05-09 antibody levels doubled that of its constituent antigens, UB09 and UB05, and this correlated with protection against malaria. The presence of enhanced UB05-09-specific antibody correlated with the absence of fever and parasitaemia, which are the main symptoms of malaria infection. The chimera is more effective in detecting and distinguishing acquired protective immunity against malaria than any of its constituents taken alone. Online B-cell epitope prediction tools confirmed the presence of B-cell epitopes in the study antigens. UB05-09 chimera is a marker of protective immunity against malaria that needs to be studied further. © 2017 John Wiley & Sons Ltd.

Prevalence of HLA-B27 antigen in patients with juvenile idiopathic arthritis.

PubMed

Żuber, Zbigniew; Turowska-Heydel, Dorota; Sobczyk, Małgorzata; Chudek, Jerzy

2015-01-01

Human leukocyte antigen B27 (HLA-B27) is considered as a risk factor for development of juvenile idiopathic arthritis (JIA). The aim of this study was to analyse the prevalence of HLA-B27 antigen in JIA categories and its influence on disease onset and response to conventional therapy. The retrospective analysis included 461 unselected children with JIA hospitalized in a single reference rheumatology centre between July 2007 and June 2012. The diagnosis was based on criteria by the International League of Association for Rheumatology. HLA-B27 was determined in 387 of all patients (84%) by hybridization of the amplified, labelled product to immobilize it on the microarray probe. HLA-B27 antigen was found in 104 of 383 affected children (27.2%), 48 of 206 girls (23.3%), and 56 of 177 boys (31.6%) - most frequently in patients with enthesitis-related arthritis (71%), psoriatic arthritis (50%) and unclassified cases (86.7%). The age of JIA onset was slightly (by 1 year) but significantly different in patients with and without HLA-B27 antigen [11 (8.5-14) vs. 10 (5-13.5) years.; p < 0.001]. The use of disease-modifying antirheumatic drugs (DMARDs) and corticosteroids was more frequently clinically ineffective in HLA-B27 positive than negative patients (23.1% vs. 15.2%; p = 0.09). Patients with polyarthritis, systemic, and psoriatic arthritis more frequently received biological therapy. HLA-B27 positive patients with enthesitis-related arthritis received biological therapy more frequently than HLA-B27 negative ones (20.4% vs. 0, respectively; p = 0.09). HLA-B27 antigen is a strong risk factor for the development of enthesitis-related arthritis, and to a lesser extent for psoriatic arthritis and extended course of oligoarthritis. The presence of this antigen does not affect the disease onset but seems to predict resistance to therapy with disease-modifying drugs and corticosteroids.

Prevalence of HLA-B27 antigen in patients with juvenile idiopathic arthritis

PubMed Central

Turowska-Heydel, Dorota; Sobczyk, Małgorzata; Chudek, Jerzy

2015-01-01

Introduction Human leukocyte antigen B27 (HLA-B27) is considered as a risk factor for development of juvenile idiopathic arthritis (JIA). The aim of this study was to analyse the prevalence of HLA-B27 antigen in JIA categories and its influence on disease onset and response to conventional therapy. Material and methods The retrospective analysis included 461 unselected children with JIA hospitalized in a single reference rheumatology centre between July 2007 and June 2012. The diagnosis was based on criteria by the International League of Association for Rheumatology. HLA-B27 was determined in 387 of all patients (84%) by hybridization of the amplified, labelled product to immobilize it on the microarray probe. Results HLA-B27 antigen was found in 104 of 383 affected children (27.2%), 48 of 206 girls (23.3%), and 56 of 177 boys (31.6%) – most frequently in patients with enthesitis-related arthritis (71%), psoriatic arthritis (50%) and unclassified cases (86.7%). The age of JIA onset was slightly (by 1 year) but significantly different in patients with and without HLA-B27 antigen [11 (8.5–14) vs. 10 (5–13.5) years.; p < 0.001]. The use of disease-modifying antirheumatic drugs (DMARDs) and corticosteroids was more frequently clinically ineffective in HLA-B27 positive than negative patients (23.1% vs. 15.2%; p = 0.09). Patients with polyarthritis, systemic, and psoriatic arthritis more frequently received biological therapy. HLA-B27 positive patients with enthesitis-related arthritis received biological therapy more frequently than HLA-B27 negative ones (20.4% vs. 0, respectively; p = 0.09). Conclusions HLA-B27 antigen is a strong risk factor for the development of enthesitis-related arthritis, and to a lesser extent for psoriatic arthritis and extended course of oligoarthritis. The presence of this antigen does not affect the disease onset but seems to predict resistance to therapy with disease-modifying drugs and corticosteroids. PMID:27407238

21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

21 CFR 660.1 - Antibody to Hepatitis B Surface Antigen.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Antibody to Hepatitis B Surface Antigen. 660.1... Hepatitis B Surface Antigen § 660.1 Antibody to Hepatitis B Surface Antigen. (a) Proper name and definition. The proper name of this product shall be Antibody to Hepatitis B Surface Antigen. The product is...

Recombinant vaccine displaying the loop-neutralizing determinant from protective antigen completely protects rabbits from experimental inhalation anthrax.

PubMed

Oscherwitz, Jon; Yu, Fen; Jacobs, Jana L; Cease, Kemp B

2013-03-01

We previously showed that a multiple antigenic peptide (MAP) vaccine displaying amino acids (aa) 304 to 319 from the 2β2-2β3 loop of protective antigen was capable of protecting rabbits from an aerosolized spore challenge with Bacillus anthracis Ames strain. Antibodies to this sequence, referred to as the loop-neutralizing determinant (LND), are highly potent at neutralizing lethal toxin yet are virtually absent in rabbit and human protective antigen (PA) antiserum. While the MAP vaccine was protective against anthrax, it contains a single heterologous helper T cell epitope which may be suboptimal for stimulating an outbred human population. We therefore engineered a recombinant vaccine (Rec-LND) containing two tandemly repeated copies of the LND fused to maltose binding protein, with enhanced immunogenicity resulting from the p38/P4 helper T cell epitope from Schistosoma mansoni. Rec-LND was found to be highly immunogenic in four major histocompatibility complex (MHC)-diverse strains of mice. All (7/7) rabbits immunized with Rec-LND developed high-titer antibody, 6 out of 7 developed neutralizing antibody, and all rabbits were protected from an aerosolized spore challenge of 193 50% lethal doses (LD(50)) of the B. anthracis Ames strain. Survivor serum from Rec-LND-immunized rabbits revealed significantly increased neutralization titers and specific activity compared to prechallenge levels yet lacked PA or lethal factor (LF) antigenemia. Control rabbits immunized with PA, which were also completely protected, appeared sterilely immune, exhibiting significant declines in neutralization titer and specific activity compared to prechallenge levels. We conclude that Rec-LND may represent a prototype anthrax vaccine for use alone or potentially combined with PA-containing vaccines.

Protection against rat vaginal candidiasis by adoptive transfer of vaginal B lymphocytes.

PubMed

De Bernardis, Flavia; Santoni, Giorgio; Boccanera, Maria; Lucciarini, Roberta; Arancia, Silvia; Sandini, Silvia; Amantini, Consuelo; Cassone, Antonio

2010-06-01

Vulvovaginal candidiasis is a mucosal infection affecting many women, but the immune mechanisms operating against Candida albicans at the mucosal level remain unknown. A rat model was employed to further characterize the contribution of B and T cells to anti-Candida vaginal protection. Particularly, the protective role of vaginal B cells was studied by means of adoptive transfer of vaginal CD3(-) CD5(+) IgM(+) cells from Candida-immunized rats to naïve animals. This passive transfer of B cells resulted into a number of vaginal C. albicans CFU approximately 50% lower than their controls. Sorted CD3(-) CD5(+) IgM(+) vaginal B lymphocytes from Candida-infected rats proliferated in response to stimulation with an immunodominant mannoprotein (MP) antigen of the fungus. Importantly, anti-MP antibodies and antibody-secreting B cells were detected in the supernatant and cell cultures, respectively, of vaginal B lymphocytes from infected rats incubated in vitro with vaginal T cells and stimulated with MP. No such specific antibodies were found when using vaginal B cells from uninfected rats. Furthermore, inflammatory and anti-inflammatory cytokines, such as interleukin-2 (IL-2), IL-6 and IL-10, were found in the supernatant of vaginal B cells from infected rats. These data are evidence of a partial anti-Candida protective role of CD3(-) CD5(+) IgM(+) vaginal B lymphocytes in our experimental model.

HD-03/ES: A Herbal Medicine Inhibits Hepatitis B Surface Antigen Secretion in Transfected Human Hepatocarcinoma PLC/PRF/5 Cells.

PubMed

Varma, Sandeep R; Sundaram, R; Gopumadhavan, S; Vidyashankar, Satyakumar; Patki, Pralhad S

2013-01-01

HD-03/ES is a herbal formulation used for the treatment of hepatitis B. However, the molecular mechanism involved in the antihepatitis B (HBV) activity of this drug has not been studied using in vitro models. The effect of HD-03/ES on hepatitis B surface antigen (HBsAg) secretion and its gene expression was studied in transfected human hepatocarcinoma PLC/PRF/5 cells. The anti-HBV activity was tested based on the inhibition of HBsAg secretion into the culture media, as detected by HBsAg-specific antibody-mediated enzyme assay (ELISA) at concentrations ranging from 125 to 1000  μ g/mL. The effect of HD-03/ES on HBsAg gene expression was analyzed using semiquantitative multiplex RT-PCR by employing specific primers. The results showed that HD-03/ES suppressed HBsAg production with an IC50 of 380  μ g/mL in PLC/PRF/5 cells for a period of 24 h. HD-03/ES downregulated HBsAg gene expression in PLC/PRF/5 cells. In conclusion, HD-03/ES exhibits strong anti-HBV properties by inhibiting the secretion of hepatitis B surface antigen in PLC/PRF/5 cells, and this action is targeted at the transcription level. Thus, HD-03/ES could be beneficial in the treatment of acute and chronic hepatitis B infections.

γδ T cells recognize a microbial encoded B cell antigen to initiate a rapid antigen specific Interleukin 17 response

PubMed Central

Zeng, Xun; Wei, Yu-ling; Huang, Jun; Newell, Evan W.; Yu, Hongxiang; Kidd, Brian A.; Kuhns, Michael S.; Waters, Ray W.; Davis, Mark M.; Weaver, Casey T.; Chien, Yueh-hsiu

2012-01-01

Summary γδ T cells contribute uniquely to host immune defense. However, how they function remains an enigma. Although it is unclear what most γδ T cells recognize, common dogma asserts that they recognize self-antigens. While they are the major initial Interleukin-17 (IL-17) producers in infections, it is unclear what is required to trigger these cells to act. Here, we report that a noted B cell antigen, the algae protein-phycoerythrin (PE) is an antigen for murine and human γδ T cells. PE also stained specific bovine γδ T cells. Employing this specificity, we demonstrated that antigen recognition, but not extensive clonal expansion, was required to activate naïve γδ T cells to make IL-17. In this activated state, γδ T cells gained the ability to respond to cytokine signals that perpetuated the IL-17 production. These results underscore the adaptability of lymphocyte antigen receptors and suggest a previously unrecognized antigen-driven rapid response in protective immunity prior to the maturation of classical adaptive immunity. PMID:22960222

Studies by immune electron microscopy of hepatitis B surface antigen in PLC/PRF/5 cells.

PubMed

Shibayama, T; Watanabe, T; Kojima, H; Yoshikawa, A; Watanabe, S; Kamimura, T; Suzuki, S; Ichida, F

1984-01-01

Electron microscopic studies of the morphology of hepatitis B surface antigen (HBsAg) produced by PLC/PRF/5 cells in vitro were carried out. Aggregates of 20-nm spherical particles in 3-day culture supernatants were observed by immune electron microscopy (IEM). Aggregates of tubular structures were found with IEM in the extracts of the cells. Tubular structures 18 to 22 nm in diameter were seen by electron microscopy (EM) in the cisternae of the endoplasmic reticulum in 2-3% of the cells. The tubular structures in the cytoplasm and extracts of PLC/PRF/5 cells resembled those observed in the hepatocytes of human carriers of hepatitis B virus (HBV). Intracellular localization of HBsAg in PLC/PRF/5 cells by direct peroxidase-conjugated antibody staining was observed on the tubular structures and the cisternal wall, which contained these structures. Rotation technique analysis indicated that the tubular structures were composed of 11 or 12 subunits.

Expression of H5 hemagglutinin vaccine antigen in common duckweed (Lemna minor) protects against H5N1 high pathogenicity avian influenza virus challenge in immunized chickens.

PubMed

Bertran, Kateri; Thomas, Colleen; Guo, Xuan; Bublot, Michel; Pritchard, Nikki; Regan, Jeffrey T; Cox, Kevin M; Gasdaska, John R; Dickey, Lynn F; Kapczynski, Darrell R; Swayne, David E

2015-07-09

A synthetic hemagglutinin (HA) gene from the highly pathogenic avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1) (Indo/03) was expressed in aquatic plant Lemna minor (rLemna-HA). In Experiment 1, efficacy of rLemna-HA was tested on birds immunized with 0.2μg or 2.3 μg HA and challenged with 10(6) mean chicken embryo infectious doses (EID50) of homologous virus strain. Both dosages of rLemna-HA conferred clinical protection and dramatically reduced viral shedding. Almost all the birds immunized with either dosage of rLemna-HA elicited HA antibody titers against Indo/03 antigen, suggesting an association between levels of anti-Indo/03 antibodies and protection. In Experiment 2, efficacy of rLemna-HA was tested on birds immunized with 0.9 μg or 2.2 μg HA and challenged with 10(6) EID50 of heterologous H5N1 virus strains A/chicken/Vietnam/NCVD-421/2010 (VN/10) or A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Birds challenged with VN/10 exhibited 100% survival regardless of immunization dosage, while birds challenged with PWT/06 had 50% and 30% mortality at 0.9 μg HA and 2.2 μg HA, respectively. For each challenge virus, viral shedding titers from 2.2 μg HA vaccinated birds were significantly lower than those from 0.9μg HA vaccinated birds, and titers from both immunized groups were in turn significantly lower than those from sham vaccinated birds. Even if immunized birds elicited HA titers against the vaccine antigen Indo/03, only the groups challenged with VN/10 developed humoral immunity against the challenge antigen. None (rLemna-HA 0.9 μg HA) and 40% (rLemna-HA 2.2 μg HA) of the immunized birds challenged with PWT/06 elicited pre-challenge antibody titers, respectively. In conclusion, Lemna-expressed HA demonstrated complete protective immunity against homologous challenge and suboptimal protection against heterologous challenge, the latter being similar to results from inactivated whole virus vaccines. Transgenic duckweed-derived HA could be a

Recognition of Antigen-Specific B Cell Receptors From Chronic Lymphocytic Leukemia Patients By Synthetic Antigen Surrogates

PubMed Central

Sarkar, Mohosin; Liu, Yun; Morimoto, Jumpei; Peng, Haiyong; Aquino, Claudio; Rader, Christoph; Chiorazzi, Nicholas

2014-01-01

In patients with chronic lymphocytic leukemia (CLL), a single neoplastic antigen-specific B cell accumulates and overgrows other B cells, leading to immune deficiency. CLL is often treated with drugs that ablate all B cells, leading to further weakening of humoral immunity, and a more focused therapeutic strategy capable of targeting only the pathogenic B cells would represent a significant advance. One approach to this would be to develop synthetic surrogates of the CLL antigens allowing differentiation of the CLL cells and healthy B cells in a patient. Here, we describe discovery of non-peptidic molecules capable of targeting antigen-specific B cell receptors with good affinity and selectivity using a combinatorial library screen. We demonstrate that our hit compounds act as synthetic antigen surrogates and recognize CLL cells and not healthy B cells. Additionally, we argue that the technology we developed can be used for discovery of other classes of antigen surrogates. PMID:25467125

Recognition of antigen-specific B-cell receptors from chronic lymphocytic leukemia patients by synthetic antigen surrogates.

PubMed

Sarkar, Mohosin; Liu, Yun; Morimoto, Jumpei; Peng, Haiyong; Aquino, Claudio; Rader, Christoph; Chiorazzi, Nicholas; Kodadek, Thomas

2014-12-18

In patients with chronic lymphocytic leukemia (CLL), a single neoplastic antigen-specific B cell accumulates and overgrows other B cells, leading to immune deficiency. CLL is often treated with drugs that ablate all B cells, leading to further weakening of humoral immunity, and a more focused therapeutic strategy capable of targeting only the pathogenic B cells would represent a significant advance. One approach to this would be to develop synthetic surrogates of the CLL antigens allowing differentiation of the CLL cells and healthy B cells in a patient. Here, we describe nonpeptidic molecules capable of targeting antigen-specific B cell receptors with good affinity and selectivity using a combinatorial library screen. We demonstrate that our hit compounds act as synthetic antigen surrogates and recognize CLL cells and not healthy B cells. Additionally, we argue that the technology we developed can be used to identify other classes of antigen surrogates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Protective Effect of Immunization of Rats with Holotoxin or B Subunit of Escherichia coli Heat-Labile Enterotoxin

PubMed Central

Klipstein, Frederick A.; Engert, Richard F.

1981-01-01

The relative immunogenicities of three forms of the Escherichia coli heatlabile enterotoxin (LT), the holotoxin, its B subunit, and the polymyxin-release form (PM LT) were compared by immunizing rats with various dosages of each given exclusively by the parenteral (IP/IP) or peroral (PO/PO) routes or by a combination of the two (IP/PO). The degree of protection was evaluated by challenge in ligated ileal loops, and the serum antitoxin response was determined by an enzyme-linked immunosorbent assay with homologous antigens. When given by the PO/PO route, each LT antigen provided only weak protection against the toxin and virtually none against viable LT-producing strains; serum antitoxin titers were not significantly increased. When the toxins were given after a parental primary immunization by either the IP/IP or the IP/PO routes, each LT antigen provided a dose-related increase in serum antitoxin titers and in the degree of protection against the toxin as well as against viable strains which produce LT alone (LT+/ST−) or in combination with the heat-stable toxin (LT+/ST+). The degree of protection against viable bacteria, particularly the LT+/ST+ strain, was stronger in animals which received booster immunizations by the PO route. When expressed on the basis of molar equivalents, holotoxin provided significant protection (a protection index of >5 against toxin challenge and >50% reduced secretion with bacterial challenge) with 4 to 15 times fewer moles than PM LT and up to 50 times fewer moles than the B subunit. These observations indicate that, on the basis of molar equivalents, the holotoxin (which contains one A plus five or six B subunits) is a more potent immunogen than either PM LT (which contains one A and probably one B subunit) or the B subunit. PMID:7011990

Using Antigen-Specific B Cells to Combine Antibody and T Cell-Based Cancer Immunotherapy.

PubMed

Wennhold, Kerstin; Thelen, Martin; Schlößer, Hans Anton; Haustein, Natalie; Reuter, Sabrina; Garcia-Marquez, Maria; Lechner, Axel; Kobold, Sebastian; Rataj, Felicitas; Utermöhlen, Olaf; Chakupurakal, Geothy; Theurich, Sebastian; Hallek, Michael; Abken, Hinrich; Shimabukuro-Vornhagen, Alexander; von Bergwelt-Baildon, Michael

2017-09-01

Cancer immunotherapy by therapeutic activation of T cells has demonstrated clinical potential. Approaches include checkpoint inhibitors and chimeric antigen receptor T cells. Here, we report the development of an alternative strategy for cellular immunotherapy that combines induction of a tumor-directed T-cell response and antibody secretion without the need for genetic engineering. CD40 ligand stimulation of murine tumor antigen-specific B cells, isolated by antigen-biotin tetramers, resulted in the development of an antigen-presenting phenotype and the induction of a tumor antigen-specific T-cell response. Differentiation of antigen-specific B cells into antibody-secreting plasma cells was achieved by stimulation with IL21, IL4, anti-CD40, and the specific antigen. Combined treatment of tumor-bearing mice with antigen-specific CD40-activated B cells and antigen-specific plasma cells induced a therapeutic antitumor immune response resulting in remission of established tumors. Human CEA or NY-ESO-1-specific B cells were detected in tumor-draining lymph nodes and were able to induce antigen-specific T-cell responses in vitro, indicating that this approach could be translated into clinical applications. Our results describe a technique for the exploitation of B-cell effector functions and provide the rationale for their use in combinatorial cancer immunotherapy. Cancer Immunol Res; 5(9); 730-43. ©2017 AACR . ©2017 American Association for Cancer Research.

Immunodiagnostic Value of Echinococcus Granulosus Recombinant B8/1 Subunit of Antigen B.

PubMed

Savardashtaki, Amir; Sarkari, Bahador; Arianfar, Farzane; Mostafavi-Pour, Zohreh

2017-06-01

Cystic echinococcosis (CE), as a chronic parasitic disease, is a major health problem in many countries. The performance of the currently available serodiagnostic tests for the diagnosis of CE is unsatisfactory. The current study aimed at sub-cloning a gene, encoding the B8/1 subunit of antigen B (AgB) from Echinococcus granulosus, using gene optimization for the immunodiagnosis of human CE. The coding sequence for AgB8/1 subunit of Echinococcus granulosus was selected from GenBank and was gene-optimized. The sequence was synthesized and inserted into pGEX-4T-1 vector. Purification was performed with GST tag affinity column. Diagnostic performance of the produced recombinant antigen, native antigen B and a commercial ELISA kit were further evaluated in an ELISA system, using a panel of sera from CE patients and controls. SDS-PAGE demonstrated that the protein of interest had a high expression level and purity after GST tag affinity purification. Western blotting verified the immunoreactivity of the produced recombinant antigen with the sera of CE patients. In an ELISA system, the sensitivity and specificity (for human CE diagnosis) of the recombinant antigen, native antigen B and commercial kit were respectively 93% and 92%, 87% and 90% and 97% and 95%. The produced recombinant antigen showed a high diagnostic value which can be recommended for serodiagnosis of CE in Iran and other CE-endemic areas. Utilizing the combination of other subunits of AgB8 would improve the performance value of the introduced ELISA system.

Protective Immunity Against a Lethal Respiratory Yersinia pestis Challenge Induced by V Antigen or the F1 Capsular Antigen Incorporated into Adenovirus Capsid

PubMed Central

Boyer, Julie L.; Sofer-Podesta, Carolina; Ang, John; Hackett, Neil R.; Chiuchiolo, Maria J.; Senina, Svetlana; Perlin, David

2010-01-01

Abstract The aerosol form of the bacterium Yersinia pestis causes pneumonic plague, a rapidly fatal disease that is a biothreat if deliberately released. At present, no plague vaccines are available for use in the United States, but subunit vaccines based on the Y. pestis V antigen and F1 capsular protein show promise when administered with adjuvants. In the context that adenovirus (Ad) gene transfer vectors have a strong adjuvant potential related to the ability to directly infect dendritic cells, we hypothesized that modification of the Ad5 capsid to display either the Y. pestis V antigen or the F1 capsular antigen on the virion surface would elicit high V antigen- or F1-specific antibody titers, permit boosting with the same Ad serotype, and provide better protection against a lethal Y. pestis challenge than immunization with equivalent amounts of V or F1 recombinant protein plus conventional adjuvant. We constructed AdYFP-pIX/V and AdLacZ-pIX/F1, E1–, E3– serotype 5 Ad gene transfer vectors containing a fusion of the sequence for either the Y. pestis V antigen or the F1 capsular antigen to the carboxy-terminal sequence of pIX, a capsid protein that can accommodate the entire V antigen (37 kDa) or F1 protein (15 kDa) without disturbing Ad function. Immunization with AdYFP-pIX/V followed by a single repeat administration of the same vector at the same dose resulted in significantly better protection of immunized animals compared with immunization with a molar equivalent amount of purified recombinant V antigen plus Alhydrogel adjuvant. Similarly, immunization with AdLacZ-pIX/F1 in a prime–boost regimen resulted in significantly enhanced protection of immunized animals compared with immunization with a molar-equivalent amount of purified recombinant F1 protein plus adjuvant. These observations demonstrate that Ad vaccine vectors containing pathogen-specific antigens fused to the pIX capsid protein have strong adjuvant properties and stimulate more robust

Prime-boost bacillus Calmette-Guérin vaccination with lentivirus-vectored and DNA-based vaccines expressing antigens Ag85B and Rv3425 improves protective efficacy against Mycobacterium tuberculosis in mice.

PubMed

Xu, Ying; Yang, Enzhuo; Wang, Jianguang; Li, Rui; Li, Guanghua; Liu, Guoyuan; Song, Na; Huang, Qi; Kong, Cong; Wang, Honghai

2014-10-01

To prevent the global spread of tuberculosis (TB), more effective vaccines and vaccination strategies are urgently needed. As a result of the success of bacillus Calmette-Guérin (BCG) in protecting children against miliary and meningeal TB, the majority of individuals will have been vaccinated with BCG; hence, boosting BCG-primed immunity will probably be a key component of future vaccine strategies. In this study, we compared the ability of DNA-, protein- and lentiviral vector-based vaccines that express the antigens Ag85B and Rv3425 to boost the effects of BCG in the context of immunity and protection against Mycobacterium tuberculosis in C57BL/6 mice. Our results demonstrated that prime-boost BCG vaccination with a lentiviral vector expressing the antigens Ag85B and Rv3425 significantly enhanced immune responses, including T helper type 1 and CD8(+) cytotoxic T lymphocyte responses, compared with DNA- and protein-based vaccines. However, lentivirus-vectored and DNA-based vaccines greatly improved the protective efficacy of BCG against M. tuberculosis, as indicated by a lack of weight loss and significantly reduced bacterial loads and histological damage in the lung. Our study suggests that the use of lentiviral or DNA vaccines containing the antigens Ag85B and Rv3425 to boost BCG is a good choice for the rational design of an efficient vaccination strategy against TB. © 2014 John Wiley & Sons Ltd.

Immunological correlates for protection against intranasal challenge of Bacillus anthracis spores conferred by a protective antigen-based vaccine in rabbits.

PubMed

Weiss, Shay; Kobiler, David; Levy, Haim; Marcus, Hadar; Pass, Avi; Rothschild, Nili; Altboum, Zeev

2006-01-01

Correlates between immunological parameters and protection against Bacillus anthracis infection in animals vaccinated with protective antigen (PA)-based vaccines could provide surrogate markers to evaluate the putative protective efficiency of immunization in humans. In previous studies we demonstrated that neutralizing antibody levels serve as correlates for protection in guinea pigs (S. Reuveny et al., Infect. Immun. 69:2888-2893, 2001; H. Marcus et al., Infect. Immun. 72:3471-3477, 2004). In this study we evaluated similar correlates for protection by active and passive immunization of New Zealand White rabbits. Full immunization and partial immunization were achieved by single and multiple injections of standard and diluted doses of a PA-based vaccine. Passive immunization was carried out by injection of immune sera from rabbits vaccinated with PA-based vaccine prior to challenge with B. anthracis spores. Immunized rabbits were challenged by intranasal spore instillation with one of two virulent strains (strains Vollum and ATCC 6605). The immune competence was estimated by measuring the level of total anti-PA antibodies, the neutralizing antibody titers, and the conferred protective immunity. The results indicate that total anti-PA antibody titers greater than 1 x 10(5) conferred protection, whereas lower titers (between 10(4) and 10(5)) provided partial protection but failed to predict protection. Neutralizing antibody titers between 500 and 800 provided partial protection, while titers higher than 1,000 conferred protection. In conclusion, this study emphasizes that regardless of the immunization regimen or the time of challenge, neutralizing antibody titers are better predictors of protection than total anti-PA titers.

Role of the Antigen Capture Pathway in the Induction of a Neutralizing Antibody Response to Anthrax Protective Antigen.

PubMed

Verma, Anita; Ngundi, Miriam M; Price, Gregory A; Takeda, Kazuyo; Yu, James; Burns, Drusilla L

2018-02-27

Toxin neutralizing antibodies represent the major mode of protective immunity against a number of toxin-mediated bacterial diseases, including anthrax; however, the cellular mechanisms that lead to optimal neutralizing antibody responses remain ill defined. Here we show that the cellular binding pathway of anthrax protective antigen (PA), the binding component of anthrax toxin, determines the toxin neutralizing antibody response to this antigen. PA, which binds cellular receptors and efficiently enters antigen-presenting cells by receptor-mediated endocytosis, was found to elicit robust anti-PA IgG and toxin neutralizing antibody responses. In contrast, a receptor binding-deficient mutant of PA, which does not bind receptors and only inefficiently enters antigen-presenting cells by macropinocytosis, elicited very poor antibody responses. A chimeric protein consisting of the receptor binding-deficient PA mutant tethered to the binding subunit of cholera toxin, which efficiently enters cells using the cholera toxin receptor rather than the PA receptor, elicited an anti-PA IgG antibody response similar to that elicited by wild-type PA; however, the chimeric protein elicited a poor toxin neutralizing antibody response. Taken together, our results demonstrate that the antigen capture pathway can dictate the magnitudes of the total IgG and toxin neutralizing antibody responses to PA as well as the ratio of the two responses. IMPORTANCE Neutralizing antibodies provide protection against a number of toxin-mediated bacterial diseases by inhibiting toxin action. Therefore, many bacterial vaccines are designed to induce a toxin neutralizing antibody response. We have used protective antigen (PA), the binding component of anthrax toxin, as a model antigen to investigate immune mechanisms important for the induction of robust toxin neutralizing antibody responses. We found that the pathway used by antigen-presenting cells to capture PA dictates the robustness of the

Immunochemical characterization of the O antigens of two Proteus strains, O8-related antigen of Proteus mirabilis 12 B-r and O2-related antigen of Proteus genomospecies 5/6 12 B-k, infecting a hospitalized patient in Poland.

PubMed

Drzewiecka, Dominika; Shashkov, Alexander S; Arbatsky, Nikolay P; Knirel, Yuriy A

2016-05-01

A hospitalized 73-year-old woman was infected with a Proteus mirabilis strain, 12 B-r, isolated from the place of injection of a blood catheter. Another strain, 12 B-k, recognized as Proteus genomospecies 5 or 6, was isolated from the patient's faeces, which was an example of a nosocomial infection rather than an auto-infection. Serological investigation using ELISA and Western blotting showed that strain 12 B-k from faeces belonged to the Proteus O2 serogroup. Strain 12 B-r from the wound displayed cross-reactions with several Proteus O serogroups due to common epitopes on the core or O-specific parts of the lipopolysaccharide. Studies of the isolated 12 B-r O-specific polysaccharide by NMR spectroscopy revealed its close structural similarity to that of Proteus O8. The only difference in 12 B-r was the presence of an additional GlcNAc-linked phosphoethanolamine residue, which creates a putative epitope responsible for the cross-reactivity with Pt. mirabilis O16. The new O-antigen form could appear as a result of adaptation of the bacterium to a changing environment. On the basis of the data obtained, we suggest division of the O8 serogroup into two subgroups: O8a for strains of various Proteus species that have been previously classified into the O8 serogroup, and O8a,b for Pt. mirabilis 12 B-r, where 'a' is a common epitope and 'b' is a phosphoethanolamine-associated epitope. These findings further confirm serological and structural heterogeneity of O antigens of Proteus strains isolated lately from patients in Poland.

alpha-Galactosylceramide-loaded, antigen-expressing B cells prime a wide spectrum of antitumor immunity.

PubMed

Kim, Yeon-Jeong; Ko, Hyun-Jeong; Kim, Yun-Sun; Kim, Dong-Hyeon; Kang, Seock; Kim, Jong-Mook; Chung, Yeonseok; Kang, Chang-Yuil

2008-06-15

Most of the current tumor vaccines successfully elicit strong protection against tumor but offer little therapeutic effect against existing tumors, highlighting the need for a more effective vaccine strategy. Vaccination with tumor antigen-presenting cells can induce antitumor immune responses. We have previously shown that NKT-licensed B cells prime cytotoxic T lymphocytes (CTLs) with epitope peptide and generate prophylactic/therapeutic antitumor effects. To extend our B cell vaccine approach to the whole antigen, and to overcome the MHC restriction, we used a nonreplicating adenovirus to transduce B cells with antigenic gene. Primary B cells transduced with an adenovirus-encoding truncated Her-2/neu (AdHM) efficiently expressed Her-2/neu. Compared with the moderate antitumor activity induced by vaccination with adenovirus-transduced B cells (B/AdHM), vaccination with alpha-galactosylceramide-loaded B/AdHM (B/AdHM/alpha GalCer) induced significantly stronger antitumor immunity, especially in the tumor-bearing mice. The depletion study showed that CD4(+), CD8(+) and NK cells were all necessary for the therapeutic immunity. Confirming the results of the depletion study, B/AdHM/alpha GalCer vaccination induced cytotoxic NK cell responses but B/AdHM did not. Vaccination with B/AdHM/alpha GalCer generated Her-2/neu-specific antibodies more efficiently than B/AdHM immunization. More importantly, B/AdHM/alpha GalCer could prime Her-2/neu-specific cytotoxic T cells more efficiently and durably than B/AdHM. CD4(+) cells appeared to be necessary for the induction of antibody and CTL responses. Our results demonstrate that, with the help of NKT cells, antigen-transduced B cells efficiently induce innate immunity as well as a wide range of adaptive immunity against the tumor, suggesting that they could be used to develop a novel cellular vaccine. (c) 2008 Wiley-Liss, Inc.

Hepatitis B Core Antigen in Hepatocytes of Chronic Hepatitis B: Comparison between Indirect Immunofluorescence and Immunoperoxidase Method

PubMed Central

Tabassum, Shahina; Al-Mahtab, Mamun; Nessa, Afzalun; Jahan, Munira; Shamim Kabir, Chowdhury Mohammad; Kamal, Mohammad; Cesar Aguilar, Julio

2015-01-01

Background Hepatitis B virus (HBV) infection has many faces. Precore and core promoter mutants resemble inactive carrier status. The identification of hepatitis B core antigen (HBcAg) in hepatocytes may have variable clinical significance. The present study was undertaken to detect HBcAg in chronic hepatitis B (CHB) patients and to assess the efficacy of detection system by indirect immunofluorescence (IIF) and indirect immunoperoxidase (IIP). Materials and methods The study was done in 70 chronic HBV-infected patients. Out of 70 patients, eight (11.4%) were hepatitis B e antigen (HBeAg) positive and 62 (88.57%) were HBeAg negative. Hepatitis B core antigen was detected by indirect immunofluorescence (IIF) and indirect immunoperoxidase (IIP) methods in liver tissue. Results All HBeAg positive patients expressed HBcAg by both IIF and IIP methods. Out of 62 patients with HBeAg-negative CHB, HBcAg was detected by IIF in 55 (88.7%) patients and by IIP in 51 (82.26%) patients. A positive relation among viral load and HBcAg detection was also found. This was more evident in the case of HBeAg negative patients and showed a positive relation with HBV DNA levels. Conclusion Hepatitis B core antigen can be detected using the IIF from formalin fixed paraffin block preparation and also by IIP method. This seems to reflect the magnitudes of HBV replication in CHB. How to cite this article Raihan R, Tabassum S, Al-Mahtab M, Nessa A, Jahan M, Kabir CMS, Kamal M, Aguilar JC. Hepatitis B Core Antigen in Hepatocytes of Chronic Hepatitis B: Comparison between Indirect Immunofluorescence and Immunoperoxidase Method. Euroasian J Hepato-Gastroenterol 2015;5(1):7-10. PMID:29201677

Antigenic relatedness between glycoproteins of human respiratory syncytial virus subgroups A and B: evaluation of the contributions of F and G glycoproteins to immunity.

PubMed Central

Johnson, P R; Olmsted, R A; Prince, G A; Murphy, B R; Alling, D W; Walsh, E E; Collins, P L

1987-01-01

The degree of antigenic relatedness between human respiratory syncytial virus (RSV) subgroups A and B was estimated from antibody responses induced in cotton rats by respiratory tract infection with RSV. Glycoprotein-specific enzyme-linked immunosorbent assays of antibody responses induced by RSV infection demonstrated that the F glycoproteins of subgroups A and B were antigenically closely related (relatedness, R approximately 50%), whereas the G glycoproteins were only distantly related (R approximately 5%). Intermediate levels of antigenic relatedness (R approximately 25%) were seen in neutralizing antibodies from cotton rats infected with RSV of the two subgroups. Immunity against the F glycoprotein of subgroup A, induced by vaccinia-A2-F, conferred a high level of protection which was of comparable magnitude against challenge by RSV of either subgroup. In comparison, immunity against the G glycoprotein of subgroup A, induced by vaccinia-A2-G, conferred less complete, but significant, protection. Importantly, in vaccinia-A2-G-immunized animals, suppression of homologous challenge virus replication was significantly greater (13-fold) than that observed for the heterologous virus. PMID:3305988

Antibodies to Plasmodium falciparum antigens predict a higher risk of malaria but protection from symptoms once parasitemic.

PubMed

Greenhouse, Bryan; Ho, Benjamin; Hubbard, Alan; Njama-Meya, Denise; Narum, David L; Lanar, David E; Dutta, Sheetij; Rosenthal, Philip J; Dorsey, Grant; John, Chandy C

2011-07-01

Associations between antibody responses to Plasmodium falciparum antigens and protection against symptomatic malaria have been difficult to ascertain, in part because antibodies are potential markers of both exposure to P. falciparum and protection against disease. We measured IgG responses to P. falciparum circumsporozoite protein, liver-stage antigen 1, apical-membrane antigen 1 (AMA-1), and merozoite surface proteins (MSP) 1 and 3, in children in Kampala, Uganda, and measured incidence of malaria before and after antibody measurement. Stronger responses to all 5 antigens were associated with an increased risk of clinical malaria (P < .01) because of confounding with prior exposure to P. falciparum. However, with use of another assessment, risk of clinical malaria once parasitemic, stronger responses to AMA-1, MSP-1, and MSP-3 were associated with protection (odds ratios, 0.34, 0.36, and 0.31, respectively, per 10-fold increase; P < .01). Analyses assessing antibodies in combination suggested that any protective effect of antibodies was overestimated by associations between individual responses and protection. Using the risk of symptomatic malaria once parasitemic as an outcome may improve detection of associations between immune responses and protection from disease. Immunoepidemiology studies designed to detect mechanisms of immune protection should integrate prior exposure into the analysis and evaluate multiple immune responses.

Increased long-term immunity to Bacillus anthracis protective antigen in mice immunized with a CIA06B-adjuvanted anthrax vaccine.

PubMed

Wui, Seo Ri; Han, Ji Eun; Kim, Yeon Hee; Rhie, Gi-eun; Lee, Na Gyong

2013-04-01

Anthrax is an acute infectious disease caused by Bacillus anthracis. We previously reported that the adjuvant CIA06B, which consists of TLR4 agonist CIA05 and aluminum hydroxide (alum), enhanced the immune response to anthrax protective antigen (PA) in mice. This study was carried out to determine whether CIA06B can enhance long-term immune responses to PA in mice. BALB/c mice were immunized intramuscularly three times at 2-week intervals with recombinant PA alone or PA combined with alum or CIA06B. At 8 and 24 weeks post-immunization, the immunological responses including serum anti-PA IgG antibody titer, toxin-neutralizing antibody titer, splenic cytokine secretion and the frequency of PA-specific memory B cells were assessed. Compared with mice injected with PA alone or PA plus alum, mice injected with PA plus CIA06B had higher titers of serum anti-PA IgG antibodies, and higher frequencies of PA-specific memory B cells and interferon-γ secreting cells. Furthermore, anti-PA antibodies induced by CIA06B were more effective in neutralizing anthrax toxin. These results demonstrated that CIA06B is capable of providing long-term immunity when used as an adjuvant in a PA-based anthrax vaccine.

The Effects of Antigen-Specific IgG1 Antibody for the Pulmonary-Hypertension-Phenotype and B Cells for Inflammation in Mice Exposed to Antigen and Fine Particles from Air Pollution

PubMed Central

Park, Sung-Hyun; Chen, Wen-Chi; Durmus, Nedim; Bleck, Bertram; Reibman, Joan; Riemekasten, Gabriela; Grunig, Gabriele

2015-01-01

Air pollution is known to exacerbate chronic inflammatory conditions of the lungs including pulmonary hypertension, cardiovascular diseases and autoimmune diseases. Directly pathogenic antibodies bind pro-inflammatory cell receptors and cause or exacerbate inflammation. In contrast, anti-inflammatory antibody isotypes (e.g. mouse immunoglobulin G1, IgG1) bind inhibitory cell receptors and can inhibit inflammation. Our previous studies showed that co-exposure to antigen and urban ambient particulate matter (PM2.5) induced severe pulmonary arterial thickening and increased right ventricular systolic pressures in mice via T-cell produced cytokines, Interleukin (IL)-13 and IL-17A. The aim of the current study was to understand how B cell and antibody responses integrate into this T cell cytokine network for the pulmonary hypertension phenotype. Special focus was on antigen-specific IgG1 that is the predominant antibody in the experimental response to antigen and urban ambient PM2.5. Wild type and B cell-deficient mice were primed with antigen and then challenged with antigen and urban particulate matter and injected with antibodies as appropriate. Our data surprisingly showed that B cells were necessary for the development of increased right ventricular pressures and molecular changes in the right heart in response to sensitization and intranasal challenge with antigen and PM2.5. Further, our studies showed that both, the increase in right ventricular systolic pressure and right ventricular molecular changes were restored by reconstituting the B cell KO mice with antigen specific IgG1. In addition, our studies identified a critical, non-redundant role of B cells for the IL-17A-directed inflammation in response to exposure with antigen and PM2.5, which was not corrected with antigen-specific IgG1. In contrast, IL-13-directed inflammatory markers, as well as severe pulmonary arterial remodeling induced by challenge with antigen and PM2.5 were similar in B cell

Targeted Delivery of GP5 Antigen of PRRSV to M Cells Enhances the Antigen-Specific Systemic and Mucosal Immune Responses

PubMed Central

Du, Luping; Yu, Zhengyu; Pang, Fengjiao; Xu, Xiangwei; Mao, Aihua; Yuan, Wanzhe; He, Kongwang; Li, Bin

2018-01-01

Efficient delivery of antigens through oral immunization is a first and critical step for successful induction of mucosal immunity, which can provide protection against pathogens invading the mucosa. Membranous/microfold cells (M cells) within the mucosa can transcytose internalized antigen without degradation and thus play an important role in initiating antigen-specific mucosal immune responses through inducing secretory IgA production. In this research, we modified poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) with Ulex europaeus agglutinin 1 (UEA-1) and successfully prepared an oral vaccine delivery system, UEA-1/PLGA NPs. PLGA NPs were prepared using a standard double emulsion solvent evaporation technique, which can protect the entrapped PRRSV DNA vaccine [pcDNA3.1-SynORF5 (synthetic ORF5)] or subunit vaccine ORF5-encoded glycoprotein (GP5) from exposure to the gastrointestinal (GI) tract and release the plasmids in a controlled manner. With UEA-1 modification, the UEA-1/PLGA NPs can be effectively transported by M-cells. We investigated immune response induced by UEA-1/PLGA-SynORF5 or UEA-1/PLGA-GP5 following inoculation in mice and piglets. Compared with PLGA-SynORF5 or PLGA-GP5 NPs, UEA-1/PLGA-SynORF5, or UEA-1/PLGA-GP5 NPs stimulated significantly increased serum IgG levels and augmented intestinal IgA levels in mice and piglets (P < 0.05). Our findings indicate UEA-1/PLGA NPs can be applied as a promising and universally robust oral vaccine delivery system. PMID:29423381

Antigen-specific B memory cell responses to lipopolysaccharide (LPS) and invasion plasmid antigen (Ipa) B elicited in volunteers vaccinated with live-attenuated Shigella flexneri 2a vaccine candidates.

PubMed

Simon, J K; Wahid, R; Maciel, M; Picking, W L; Kotloff, K L; Levine, M M; Sztein, M B

2009-01-22

We evaluated B memory responses in healthy adult volunteers who received one oral dose of live-attenuated Shigella flexneri 2a vaccine. LPS-specific B(M) cells increased from a median of 0 at baseline to 20 spot forming cells (SFC)/10(6) expanded cells following vaccination (p=0.008). A strong correlation was found between post-vaccination anti-LPS B(M) cell counts and peak serum anti-LPS IgG titers (rs=0.95, p=0.0003). Increases in B(M) specific for IpaB approaching significance were also observed. In sum, oral vaccination with live-attenuated S. flexneri 2a elicits B(M) cells to LPS and IpaB, suggesting that B(M) responses to Shigella antigens should be further studied as a suitable surrogate of protection in shigellosis.

Immunization with a Recombinant, Pseudomonas fluorescens-Expressed, Mutant Form of Bacillus anthracis-Derived Protective Antigen Protects Rabbits from Anthrax Infection.

PubMed

Reed, Matthew D; Wilder, Julie A; Mega, William M; Hutt, Julie A; Kuehl, Philip J; Valderas, Michelle W; Chew, Lawrence L; Liang, Bertrand C; Squires, Charles H

2015-01-01

Protective antigen (PA), one of the components of the anthrax toxin, is the major component of human anthrax vaccine (Biothrax). Human anthrax vaccines approved in the United States and Europe consist of an alum-adsorbed or precipitated (respectively) supernatant material derived from cultures of toxigenic, non-encapsulated strains of Bacillus anthracis. Approved vaccination schedules in humans with either of these vaccines requires several booster shots and occasionally causes adverse injection site reactions. Mutant derivatives of the protective antigen that will not form the anthrax toxins have been described. We have cloned and expressed both mutant (PA SNKE167-ΔFF-315-E308D) and native PA molecules recombinantly and purified them. In this study, both the mutant and native PA molecules, formulated with alum (Alhydrogel), elicited high titers of anthrax toxin neutralizing anti-PA antibodies in New Zealand White rabbits. Both mutant and native PA vaccine preparations protected rabbits from lethal, aerosolized, B. anthracis spore challenge subsequent to two immunizations at doses of less than 1 μg.

Antigen specific suppression of humoral immunity by anergic Ars/A1 B cells1

PubMed Central

Aviszus, Katja; MacLeod, Megan K.L.; Kirchenbaum, Greg A.; Detanico, Thiago O.; Heiser, Ryan A.; St. Clair, James B.; Guo, Wenzhong; Wysocki, Lawrence J.

2012-01-01

Autoreactive anergic B lymphocytes are considered to be dangerous because of their potential for activation and recruitment into autoimmune responses. Yet they persist for days and constitute ~5% of the B cell pool. We assessed their functional potential in the Ars/A1 transgene model, where anergic B cells express a dual-reactive antigen receptor that binds, in addition to a self-antigen, the hapten p-azophenylarsonate (Ars). When Ars/A1 B cells were transferred into adoptive recipients that were immunized with foreign proteins covalently conjugated with Ars, endogenous IgG immune responses to both were selectively and severely diminished, and the development of T helper cells was impaired. Approximately 95% inhibition of the anti-Ars response was attained with ~4000 transferred Ars/A1 B cells through redundant mechanisms, one of which depended upon their expression of MHC II but not upon secretion of IL-10 or IgM. This antigen-specific suppressive activity implicates the autoreactive anergic B cell as an enforcer of immunological tolerance to self-antigens. PMID:23008448

Analysis of antigen-specific B-cell memory directly ex vivo.

PubMed

McHeyzer-Williams, Louise J; McHeyzer-Williams, Michael G

2004-01-01

Helper T-cell-regulated B-cell memory develops in response to initial antigen priming as a cellular product of the germinal center (GC) reaction. On antigen recall, memory response precursors expand rapidly with exaggerated differentiation into plasma cells to produce the high-titer, high-affinity antibody(Ab) that typifies the memory B-cell response in vivo. We have devised a high-resolution flow cytometric strategy to quantify the emergence and maintenance of antigen-specific memory B cells directly ex vivo. Extended cell surface phenotype establishes a level of cellular diversity not previously appreciated for the memory B-cell compartment. Using an "exclusion transfer" strategy, we ascertain the capacity of two distinct memory B-cell populations to transfer antigen-specific memory into naive adoptive hosts. Finally, we sequence expressed messenger ribonucleic acid (mRNA) from single cells within the population to estimate the level of somatic hypermutation as the best molecular indicator of B-cell memory. In this chapter, we describe the methods used in each of these four sections that serve to provide high-resolution quantification of antigen-specific B-cell memory responses directly ex vivo.

Cross-specificity of protective human antibodies against Klebsiella pneumoniae LPS O-antigen.

PubMed

Rollenske, Tim; Szijarto, Valeria; Lukasiewicz, Jolanta; Guachalla, Luis M; Stojkovic, Katarina; Hartl, Katharina; Stulik, Lukas; Kocher, Simone; Lasitschka, Felix; Al-Saeedi, Mohammed; Schröder-Braunstein, Jutta; von Frankenberg, Moritz; Gaebelein, Gereon; Hoffmann, Peter; Klein, Sabrina; Heeg, Klaus; Nagy, Eszter; Nagy, Gabor; Wardemann, Hedda

2018-06-01

Humoral immune responses to microbial polysaccharide surface antigens can prevent bacterial infection but are typically strain specific and fail to mediate broad protection against different serotypes. Here we describe a panel of affinity-matured monoclonal human antibodies from peripheral blood immunoglobulin M-positive (IgM + ) and IgA + memory B cells and clonally related intestinal plasmablasts, directed against the lipopolysaccharide (LPS) O-antigen of Klebsiella pneumoniae, an opportunistic pathogen and major cause of antibiotic-resistant nosocomial infections. The antibodies showed distinct patterns of in vivo cross-specificity and protection against different clinically relevant K. pneumoniae serotypes. However, cross-specificity was not limited to K. pneumoniae, as K. pneumoniae-specific antibodies recognized diverse intestinal microbes and neutralized not only K. pneumoniae LPS but also non-K. pneumoniae LPS. Our data suggest that the recognition of minimal glycan epitopes abundantly expressed on microbial surfaces might serve as an efficient humoral immunological mechanism to control invading pathogens and the large diversity of the human microbiota with a limited set of cross-specific antibodies.

Vaccination with virus-like particles containing H5 antigens from three H5N1 clades protects chickens from H5N1 and H5N8 influenza viruses

PubMed Central

Kapczynski, Darrell R.; Tumpey, Terrence M.; Hidajat, Rachmat; Zsak, Aniko; Chrzastek, Klaudia; Tretyakova, Irina; Pushko, Peter

2016-01-01

Highly pathogenic avian influenza (HPAI) viruses, especially H5N1 strains, represent a public health threat and cause widespread morbidity and mortality in domestic poultry. Recombinant virus-like particles (VLPs) represent a promising novel vaccine approach to control avian influenza including HPAI strains. Influenza VLPs contain viral hemagglutinin (HA), which can be expressed in cell culture within highly immunogenic VLPs that morphologically and antigenically resemble influenza virions, except VLPs are non-infectious. Here we describe a recombinant VLP containing HA proteins derived from three distinct clades of H5N1 viruses as an experimental, broadly protective H5 avian influenza vaccine. A baculovirus vector was configured to co-express the H5 genes from recent H5N1 HPAI isolates A/chicken/Germany/2014 (clade 2.3.4.4), A/chicken/West Java/Subang/29/2007 (clade 2.1.3) and A/chicken/Egypt/121/2012 (clade 2.2.1). Co-expression of these genes in Sf9 cells along with influenza neuraminidase (NA) and retrovirus gag genes resulted in production of triple-clade H555 VLPs that exhibited hemagglutination activity and morphologically resembled influenza virions. Vaccination of chickens with these VLPs resulted in induction of serum antibody responses and efficient protection against experimental challenges with three different viruses including the recent U.S. H5N8 HPAI isolate. We conclude that these novel triple-clade VLPs represent a feasible strategy for simultaneously evoking protective antibodies against multiple variants of H5 influenza virus. PMID:26868083

Overview of expression of hepatitis B surface antigen in transgenic plants.

PubMed

Guan, Zheng-jun; Guo, Bin; Huo, Yan-lin; Guan, Zheng-ping; Wei, Ya-hui

2010-10-28

Hepatitis B virus (HBV), a pathogen for chronic liver infection, afflicts more than 350 million people world-wide. The effective way to control the virus is to take HBV vaccine. Hepatitis B surface antigen (HBsAg) is an effective protective antigen suitable for vaccine development. At present, "edible" vaccine based on transgenic plants is one of the most promising directions in novel types of vaccines. HBsAg production from transgenic plants has been carried out, and the transgenic plant expression systems have developed from model plants (such as tobacco, potato and tomato) to other various plant platforms. Crude or purified extracts of transformed plants have been found to conduct immunological responses and clinical trials for hepatitis B, which gave the researches of plant-based HBsAg production a big boost. The aim of this review was to summarize the recent data about plant-based HBsAg development including molecular biology of HBsAg gene, selection of expression vector, the expression of HBsAg gene in plants, as well as corresponding immunological responses in animal models or human. Copyright © 2010 Elsevier Ltd. All rights reserved.

Endogenous antigen tunes the responsiveness of naive B cells but not T cells

PubMed Central

Zikherman, Julie; Parameswaran, Ramya; Weiss, Arthur

2012-01-01

In humans up to 75% of newly generated B cells and about 30% of mature B cells exhibit some degree of autoreactivity1. Yet, how B cells establish and maintain tolerance in the face of autoantigen exposure during and after development is not certain. Studies of model BCR transgenic systems have highlighted the critical role played by functional unresponsiveness or ‘anergy’2,3. Unlike T cells, evidence suggests that receptor editing and anergy, rather than deletion, account for much of B cell tolerance4,5. However, it remains unclear whether the mature diverse B cell repertoire of mice contains anergic autoreactive B cells, and if so, whether antigen was encountered during or after their development. By taking advantage of a reporter mouse in which B cell antigen receptor (BCR) signaling rapidly and robustly induces GFP expression under the control of the Nur77 regulatory region, antigen-dependent and – independent BCR signaling events in vivo during B cell maturation were visualized. Here we show that B cells encounter antigen during development in the spleen, and that this antigen exposure in turn tunes the responsiveness of BCR signaling in B cells at least partly by down-modulating expression of surface IgM but not IgD BCRs, and by modifying basal calcium levels. By contrast, no analogous process occurs in naive mature T cells. Our data demonstrate not only that autoreactive B cells persist in the mature repertoire, but that functional unresponsiveness or ‘anergy’ exists in the mature B cell repertoire along a continuum, a fact that has long been suspected, but never yet shown. These results have important implications for understanding how tolerance in T and B cells is differently imposed, and how these processes might go awry in disease. PMID:22902503

A Longitudinal Hepatitis B Vaccine Cohort Demonstrates Long-lasting Hepatitis B Virus (HBV) Cellular Immunity Despite Loss of Antibody Against HBV Surface Antigen.

PubMed

Simons, Brenna C; Spradling, Philip R; Bruden, Dana J T; Zanis, Carolyn; Case, Samantha; Choromanski, Tammy L; Apodaca, Minjun; Brogdon, Hazel D; Dwyer, Gaelen; Snowball, Mary; Negus, Susan; Bruce, Michael G; Morishima, Chihiro; Knall, Cindy; McMahon, Brian J

2016-07-15

Long-lasting protection resulting from hepatitis B vaccine, despite loss of antibody against hepatitis B virus (HBV) surface antigen (anti-HBs), is undetermined. We recruited persons from a cohort vaccinated with plasma-derived hepatitis B vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array. Study subgroups were defined 32 years after vaccination as having an anti-HBs level of either ≥10 mIU/mL (group 1; n = 13) or <10 mIU/mL (group 2; n = 31). All 44 participants, regardless of anti-HBs level, tested positive for tumor necrosis factor α, interleukin 10, or interleukin 6 production by HBV surface antigen-specific T cells. The frequency of natural killer T cells correlated with the level of anti-HBs (P = .008). The proportion of participants who demonstrated T-cell responses to HBV core antigen varied among the cytokines measured, suggesting some natural exposure to HBV in the study group. No participant had evidence of breakthrough HBV infection. Evidence of long-lasting cellular immunity, regardless of anti-HBs level, suggests that protection afforded by primary immunization with plasma-derived hepatitis B vaccine during childhood and adulthood lasts at least 32 years. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Production and characterization of a recombinant chimeric antigen consisting botulinum neurotoxin serotypes A, B and E binding subdomains.

PubMed

Ebrahimi, Firouz; Rasaee, Mohammad Javad; Mousavi, Seyed Latif; Babaeipour, Valiollah

2010-02-01

Botulinum neurotoxins (BoNTs) are potent toxicant proteins composed of a heavy chain (100 kDa) and a light chain (50 kDa) of seven (A-G) serotypes that is responsible for botulism syndrome. In this study, polypeptides from C-terminal heavy chain of BoNTs serotypes A, B and E to the length of 54, 45 and 48 amino acid respectively were selected, linked together using a hydrophobic linker and expressed in E. coli. The expression efficiency of the chimeric protein was found to be 51%. The chimeric protein was produced in the form of inclusion body (IB) both at two studied temperatures, 30 degrees C and 37 degrees C. This IB was extracted by ultracentrifugation and followed for chimeric protein solubilization and purification using of ultrafiltration and preparative electrophoresis. The purified chimeric protein was characterized using blotting and ELISA. To evaluate the protection ability of this chimeric antigen against their active toxins, it was injected to mice and the antibody titer as well as the extent of protectivity were determined. Mice given three injections (10 microg/mice) of the antigen were protected against an intra-peritoneal administration of 10 LD(50 )of serotypes A and E, but 100 LD(50) of serotype B. We conclude that a significant correlation exists between the antigenic characteristics and protection capability of the chimeric protein prepared in this study.

Major neutralizing sites on vaccinia virus glycoprotein B5 are exposed differently on variola virus ortholog B6.

PubMed

Aldaz-Carroll, Lydia; Xiao, Yuhong; Whitbeck, J Charles; de Leon, Manuel Ponce; Lou, Huan; Kim, Mikyung; Yu, Jessica; Reinherz, Ellis L; Isaacs, Stuart N; Eisenberg, Roselyn J; Cohen, Gary H

2007-08-01

Immunization against smallpox (variola virus) with Dryvax, a live vaccinia virus (VV), was effective, but now safety is a major concern. To overcome this issue, subunit vaccines composed of VV envelope proteins from both forms of infectious virions, including the extracellular enveloped virion (EV) protein B5, are being developed. However, since B5 has 23 amino acid differences compared with its B6 variola virus homologue, B6 might be a better choice for such a strategy. Therefore, we compared the properties of both proteins using a panel of monoclonal antibodies (MAbs) to B5 that we had previously characterized and grouped according to structural and functional properties. The B6 gene was obtained from the Centers for Disease Control and Prevention, and the ectodomain was cloned and expressed in baculovirus as previously done with B5, allowing us to compare the antigenic properties of the proteins. Polyclonal antibodies to B5 or B6 cross-reacted with the heterologous protein, and 16 of 26 anti-B5 MAbs cross-reacted with B6. Importantly, 10 anti-B5 MAbs did not cross-react with B6. Of these, three have important anti-VV biologic properties, including their ability to neutralize EV infectivity and block comet formation. Here, we found that one of these three MAbs protected mice from a lethal VV challenge by passive immunization. Thus, epitopes that are present on B5 but not on B6 would generate an antibody response that would not recognize B6. Assuming that B6 contains similar variola virus-specific epitopes, our data suggest that a subunit vaccine using the variola virus homologues might exhibit improved protective efficacy against smallpox.

Screening of Peptide Libraries Against Protective Antigen of Bacillus Anthracis in a Disposable Microfluidic Cartridge

DTIC Science & Technology

2011-11-28

New Reprint Screening of Peptide Libraries against Protective Antigen of Bacillus anthracis in a Disposable Microfluidic Cartridge W911NF-09-D-0001...against Protective Antigen of Bacillus anthracis in a Disposable Microfluidic Cartridge Report Title ABSTRACT See attached. Screening of Peptide...Libraries against Protective Antigen of Bacillus anthracis in a Disposable Microfluidic Cartridge Joshua M. Kogot1, Yanting Zhang2, Stephen J. Moore3

Microfluidic squeezing for intracellular antigen loading in polyclonal B-cells as cellular vaccines

NASA Astrophysics Data System (ADS)

Lee Szeto, Gregory; van Egeren, Debra; Worku, Hermoon; Sharei, Armon; Alejandro, Brian; Park, Clara; Frew, Kirubel; Brefo, Mavis; Mao, Shirley; Heimann, Megan; Langer, Robert; Jensen, Klavs; Irvine, Darrell J.

2015-05-01

B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as dendritic cells. Here we utilize a microfluidic device that employs many parallel channels to pass single cells through narrow constrictions in high throughput. This microscale “cell squeezing” process creates transient pores in the plasma membrane, enabling intracellular delivery of whole proteins from the surrounding medium into B-cells via mechano-poration. We demonstrate that both resting and activated B-cells process and present antigens delivered via mechano-poration exclusively to antigen-specific CD8+T-cells, and not CD4+T-cells. Squeezed B-cells primed and expanded large numbers of effector CD8+T-cells in vitro that produced effector cytokines critical to cytolytic function, including granzyme B and interferon-γ. Finally, antigen-loaded B-cells were also able to prime antigen-specific CD8+T-cells in vivo when adoptively transferred into mice. Altogether, these data demonstrate crucial proof-of-concept for mechano-poration as an enabling technology for B-cell antigen loading, priming of antigen-specific CD8+T-cells, and decoupling of antigen uptake from B-cell activation.

Immunotherapy for B-Cell Neoplasms using T Cells expressing Chimeric Antigen Receptors

PubMed Central

Boulassel, Mohamed-Rachid; Galal, Ahmed

2012-01-01

Immunotherapy with T cells expressing chimeric antigen receptors (CAR) is being evaluated as a potential treatment for B-cell neoplasms. In recent clinical trials it has shown promising results. As the number of potential candidate antigens expands, the choice of suitable target antigens becomes more challenging to design studies and to assess optimal efficacy of CAR. Careful evaluation of candidate target antigens is required to ensure that T cells expressing CAR will preferentially kill malignant cells with a minimal toxicity against normal tissues. B cells express specific surface antigens that can theoretically act as targets for CAR design. Although many of these antigens can stimulate effective cellular immune responses in vivo, their implementation in clinical settings remains a challenge. Only targeted B-cell antigens CD19 and CD20 have been tested in clinical trials. This article reviews exploitable B cell surface antigens for CAR design and examines obstacles that could interfere with the identification of potentially useful cellular targets. PMID:23269948

Antigen Specific Responses and ANA production in B6.Sle1b mice: A role for SAP

PubMed Central

Jennings, Paula; Chan, Alice; Schwartzberg, Pamela; Wakeland, Edward K.; Yuan, Dorothy

2010-01-01

B6.Sle1b mice, which contain the Sle1b gene interval derived from lupus prone NZM2410 mice on a C57BL/6 background, present with gender-biased, highly penetrant anti-nuclear antibody (ANA) production. To obtain some insight into the possible induction mechanism of autoantibodies in these mice we compared antigen specific T dependent (TD) and T independent (TI-II) responses between B6.Sle1b and B6 mice before the development of high ANA titers. Our results show that B6.Sle1b mice mount enhanced responses to a TI-II antigen. Additionally, the memory T cell response generated by a TD antigen was also increased. This enhancement correlates with the greater ability of B cells from B6.Sle1b mice to present antigen to T cells. The SLAM Associated Protein (SAP) is critical for signaling of many of the molecules encoded by the SLAM/CD2 gene cluster, candidates for mediating the Sle1b phenotype; therefore, we also investigated the effect of sap deletion in these strains on the TD and TI-II responses as well as on ANA production. The results of these studies of responses to non-self antigens provide further insight for the mechanism by which responses to self-antigens might be initiated in the context of specific genetic alterations. PMID:18845419

Prime-boost BCG vaccination with DNA vaccines based in β-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model

PubMed Central

Cervantes-Villagrana, Alberto R.; Hernández-Pando, Rogelio; Biragyn, Arya; Castañeda-Delgado, Julio; Bodogai, Monica; Martínez-Fierro, Margarita; Sada, Eduardo; Trujillo, Valentin; Enciso-Moreno, Antonio; Rivas-Santiago, Bruno

2018-01-01

The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0–89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB. PMID:23196205

Prime-boost BCG vaccination with DNA vaccines based in β-defensin-2 and mycobacterial antigens ESAT6 or Ag85B improve protection in a tuberculosis experimental model.

PubMed

Cervantes-Villagrana, Alberto R; Hernández-Pando, Rogelio; Biragyn, Arya; Castañeda-Delgado, Julio; Bodogai, Monica; Martínez-Fierro, Margarita; Sada, Eduardo; Trujillo, Valentin; Enciso-Moreno, Antonio; Rivas-Santiago, Bruno

2013-01-11

The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0-89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB. Copyright © 2012 Elsevier Ltd. All rights reserved.

Antibodies to Plasmodium falciparum Antigens Predict a Higher Risk of Malaria But Protection From Symptoms Once Parasitemic

PubMed Central

Hubbard, Alan; Njama-Meya, Denise; Narum, David L.; Lanar, David E.; Dutta, Sheetij; Rosenthal, Philip J.; Dorsey, Grant; John, Chandy C.

2011-01-01

(See the article by Bejon et al, on pages 9–18, and Bousema et al, on pages 1–3.) Background. Associations between antibody responses to Plasmodium falciparum antigens and protection against symptomatic malaria have been difficult to ascertain, in part because antibodies are potential markers of both exposure to P. falciparum and protection against disease. Methods. We measured IgG responses to P. falciparum circumsporozoite protein, liver-stage antigen 1, apical-membrane antigen 1 (AMA-1), and merozoite surface proteins (MSP) 1 and 3, in children in Kampala, Uganda, and measured incidence of malaria before and after antibody measurement. Results. Stronger responses to all 5 antigens were associated with an increased risk of clinical malaria (P < .01) because of confounding with prior exposure to P. falciparum. However, with use of another assessment, risk of clinical malaria once parasitemic, stronger responses to AMA-1, MSP-1, and MSP-3 were associated with protection (odds ratios, 0.34, 0.36, and 0.31, respectively, per 10-fold increase; P < .01). Analyses assessing antibodies in combination suggested that any protective effect of antibodies was overestimated by associations between individual responses and protection. Conclusions. Using the risk of symptomatic malaria once parasitemic as an outcome may improve detection of associations between immune responses and protection from disease. Immunoepidemiology studies designed to detect mechanisms of immune protection should integrate prior exposure into the analysis and evaluate multiple immune responses. PMID:21628654

Association of human leukocyte antigen polymorphism with outcomes of hepatitis B virus infection.

PubMed

Ramezani, Amitis; Hasanjani Roshan, Mohammad Reza; Kalantar, Ebrahim; Eslamifar, Ali; Banifazl, Mohammad; Taeb, Jaleh; Aghakhani, Arezoo; Gachkar, Latif; Velayati, Ali Akbar

2008-11-01

Host genetic and environmental factors are viewed as a common basis of the different outcomes of hepatitis B virus (HBV) infection. Human leukocyte antigen (HLA) plays an important role in immunological reaction to HBV infection. In this study, we aimed to determine the association between HBV infection and HLA-A, B, and DRB1 alleles in northern Iran. HLA-A, B, and DRB1 alleles in 33 patients with chronic hepatitis B (CHB) and 31 healthy carriers as the persistent group, and 30 subjects who had spontaneously recovered from HBV infection were analyzed by using the polymerase chain reaction (PCR)-sequence-specific primer (PCR-SSP) technique. The frequency of the HLA-A*33 allele was higher in the persistent group than in the recovered group (10.16% vs 0%, P < 0.008); the frequency of the DRB1*13 allele was lower in the persistent group than in the recovered group (3.13% vs 11.67%, P < 0.03). The frequency of the B*52 allele was higher in CHB patients than healthy carriers (7.58% vs 0%, P < 0.05). The logistic regression model showed that the presence of the HLA-DRB1*13 allele was the significant factor associated with protection against the persistency of HBV. There were significant differences between the HBV recovered group, CHB patients, and healthy carriers regarding age, hepatitis B e antigen, and anti-hepatitis B e positivity. HLA-A*33 was closely related with susceptibility to persisting hepatitis B infection, and HLA-DRB1*13 was closely related with protection against persisting hepatitis B in an Iranian population. These findings emphasized that the host HLA polymorphism is an important factor in determining the outcome of HBV infection.

[Comparative studies of serological typing and HLA-A, B antigen genotyping with PCR using sequence-specific primers].

PubMed

Wu, Da-lin; Ling, Han-xin; Tang, Hao

2004-11-01

To evaluate the accuracy of PCR with sequence-specific primers (PCR-SSP) for HLA-I genotyping and analyze the causes of the errors occurring in the genotyping. DNA samples and were obtained from 34 clinical patients, and serological typing with monoclonal antibody (mAb) and HLA-A and, B antigen genotyping with PCR-SSP were performed. HLA-A and, B alleles were successfully typed in 34 clinical samples by mAb and PCR-SSP. No false positive or false negative results were found, and the erroneous and missed diagnosis rates were obviously higher in serological detection, being 23.5% for HLA-A and 26.5% for HLA-B. Error or confusion was more likely to occur in the antigens of A2 and A68, A32 and A33, B5, B60 and B61. DNA typing for HLA-I class (A, B antigens) by PCR-SSP has high resolution, high specificity, and good reproducibility, which is more suitable for clinical application than serological typing. PCR-SSP may accurately detect the alleles that are easily missed or mistaken in serological typing.

Antigen-specific T-cell lines transfer protective immunity against Trichinella spiralis in vivo.

PubMed Central

Riedlinger, J; Grencis, R K; Wakelin, D

1986-01-01

T-cell lines specific for infective muscle larvae antigens of the intestinal nematode Trichinella spiralis have been generated in vitro. These antigen-specific T-cell lines express the L3T4+ Ly2- phenotype and secrete the lymphokines IL-2, IL-3 and gamma-IFN. They are stable in culture for up to 15 weeks and are protective when adoptively transferred into naive recipients. As few as 2 x 10(5) T. spiralis-specific tract. In addition, intestinal mastocytosis and peripheral blood eosinophilia were accelerated after adoptive transfer of T. spiralis-specific T-cell lines. PMID:2423438

Major Neutralizing Sites on Vaccinia Virus Glycoprotein B5 Are Exposed Differently on Variola Virus Ortholog B6▿

PubMed Central

Aldaz-Carroll, Lydia; Xiao, Yuhong; Whitbeck, J. Charles; de Leon, Manuel Ponce; Lou, Huan; Kim, Mikyung; Yu, Jessica; Reinherz, Ellis L.; Isaacs, Stuart N.; Eisenberg, Roselyn J.; Cohen, Gary H.

2007-01-01

Immunization against smallpox (variola virus) with Dryvax, a live vaccinia virus (VV), was effective, but now safety is a major concern. To overcome this issue, subunit vaccines composed of VV envelope proteins from both forms of infectious virions, including the extracellular enveloped virion (EV) protein B5, are being developed. However, since B5 has 23 amino acid differences compared with its B6 variola virus homologue, B6 might be a better choice for such a strategy. Therefore, we compared the properties of both proteins using a panel of monoclonal antibodies (MAbs) to B5 that we had previously characterized and grouped according to structural and functional properties. The B6 gene was obtained from the Centers for Disease Control and Prevention, and the ectodomain was cloned and expressed in baculovirus as previously done with B5, allowing us to compare the antigenic properties of the proteins. Polyclonal antibodies to B5 or B6 cross-reacted with the heterologous protein, and 16 of 26 anti-B5 MAbs cross-reacted with B6. Importantly, 10 anti-B5 MAbs did not cross-react with B6. Of these, three have important anti-VV biologic properties, including their ability to neutralize EV infectivity and block comet formation. Here, we found that one of these three MAbs protected mice from a lethal VV challenge by passive immunization. Thus, epitopes that are present on B5 but not on B6 would generate an antibody response that would not recognize B6. Assuming that B6 contains similar variola virus-specific epitopes, our data suggest that a subunit vaccine using the variola virus homologues might exhibit improved protective efficacy against smallpox. PMID:17522205

Characterization of antigenic determinants in ApxIIA exotoxin capable of inducing protective immunity to Actinobacillus pleuropneumoniae challenge.

PubMed

Seo, Ki-Weon; Kim, Dong-Heon; Kim, Ah Hyun; Yoo, Han-Sang; Lee, Kyung-Yeol; Jang, Yong-Suk

2011-01-01

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. Among the virulence factors of the pathogen, ApxIIA, a bacterial exotoxin, is expressed by many serotypes and presents a plausible target for vaccine development. We characterized the region within ApxIIA that induces a protective immune response against bacterial infection using mouse challenge model. Recombinant proteins spanning the length of ApxIIA were produced and antiserum to the full-length ApxIIA was induced in mice. This antiserum recognized fragments #2, #3 and #5 with high binding specificity, but showed poor recognition for fragments #1 and #4. Of the antisera induced in mice by injection of each fragments, only the antiserum to fragment #4 failed to efficiently recognize the full-length antigen, although the individual antisera recognized their cognate antigens with almost equal efficiency. The protective potency of the immunogenic proteins against a challenge injection of bacteria in vivo correlated well with the antibody titer. Fragment #5 induced the highest level of protective activity, comparable to that by the full-length protein. These results support the use of fragment #5 to produce a vaccine against A. pleuropneumoniae challenge, since the small antigen peptide is easier to handle than is the full-length protein and can be expressed efficiently in heterologous expression systems.

Antigenic topology of chlamydial PorB protein and identification of targets for immune neutralization of infectivity.

PubMed

Kawa, Diane E; Stephens, Richard S

2002-05-15

The outer membrane protein PorB is a conserved chlamydial protein that functions as a porin and is capable of eliciting neutralizing Abs. A topological antigenic map was developed using overlapping synthetic peptides representing the Chlamydia trachomatis PorB sequence and polyclonal immune sera. To identify which antigenic determinants were surface accessible, monospecific antisera were raised to the PorB peptides and were used in dot-blot and ELISA-based absorption studies with viable chlamydial elementary bodies (EBs). The ability of the surface-accessible antigenic determinants to direct neutralizing Ab responses was investigated using standardized in vitro neutralization assays. Four major antigenic clusters corresponding to Phe(34)-Leu(59) (B1-2 and B1-3), Asp(112) -Glu(145) (B2-3 and B2-4), Gly(179)-Ala(225) (B3-2 to B3-4), and Val(261)-Asn(305) (B4-4 to B5-2) were identified. Collectively, the EB absorption and dot-blot assays established that the immunoreactive PorB Ags were exposed on the surface of chlamydial EBs. Peptide-specific antisera raised to the surface-accessible Ags neutralized chlamydial infectivity and demonstrated cross-reactivity to synthetic peptides representing analogous C. pneumoniae PorB sequences. Furthermore, neutralization of chlamydial infectivity by C. trachomatis PorB antisera was inhibited by synthetic peptides representing the surface-exposed PorB antigenic determinants. These findings demonstrate that PorB Ags may be useful for development of chlamydial vaccines.

Antigen-specific B memory cell responses to lipopolysaccharide (LPS) and invasion plasmid antigen (Ipa) B elicited in volunteers vaccinated with live-attenuated Shigella flexneri 2a vaccine candidates

PubMed Central

Simon, J.K.; Wahid, R.; Maciel, M.; Picking, W.L.; Kotloff, K.L.; Levine, M.M.; Sztein, M.B.

2013-01-01

We evaluated B memory responses in healthy adult volunteers who received one oral dose of live-attenuated Shigella flexneri 2a vaccine. LPS-specific BM cells increased from a median of 0 at baseline to 20 spot forming cells (SFC)/106 expanded cells following vaccination (p = 0.008). A strong correlation was found between post-vaccination anti-LPS BM cell counts and peak serum anti-LPS IgG titers (rs = 0.95, p = 0.0003). Increases in BM specific for IpaB approaching significance were also observed. In sum, oral vaccination with live-attenuated S. flexneri 2a elicits BM cells to LPS and IpaB, suggesting that BM responses to Shigella antigens should be further studied as a suitable surrogate of protection in shigellosis. PMID:19022324

Expression of the Bacillus anthracis protective antigen gene by baculovirus and vaccinia virus recombinants.

PubMed Central

Iacono-Connors, L C; Schmaljohn, C S; Dalrymple, J M

1990-01-01

The gene encoding Bacillus anthracis protective antigen (PA) was modified by site-directed mutagenesis, subcloned into baculovirus and vaccinia virus plasmid transfer vectors (pAcYM1 and pSC-11, respectively), and inserted via homologous recombinations into baculovirus Autographa californica nuclear polyhedrosis virus or vaccinia virus (strains WR and Connaught). Expression of PA was detected in both systems by immunofluorescence assays with antisera from rabbits immunized with B. anthracis PA. Western blot (immunoblot) analysis showed that the expressed product of both systems was slightly larger (86 kilodaltons) than B. anthracis-produced PA (83.5 kilodaltons). Analysis of trypsin digests of virus-expressed and authentic PA suggested that the size difference was due to the presence of a signal sequence remaining with the virus-expressed protein. Immunization of mice with either recombinant baculovirus-infected Spodoptera frugiperda cells or with vaccinia virus recombinants elicited a high-titer, anti-PA antibody response. Images PMID:2105271

Hepatitis B antigen and viral hepatitis type B in India*

PubMed Central

John, T. Jacob; Carman, Robert H.; Hill, Peter G.

1974-01-01

Surveys were conducted to determine the occurrence of overt hepatitis manifested by jaundice in groups of hospital patients who had survived their initial illness. Of those who had been given blood that had not been screened for the presence of hepatitis B antigen (HB Ag) 9.4% reported that they had had jaundice during the 6 months following transfusion. During a similar period jaundice was reported by only 1.1% of those who had received blood found to be negative for HB Ag by the cross-over electrophoresis test. This difference is highly significant. Jaundice was reported by 25.5% of recipients of HB Ag-positive blood. Of a control population of hospitalized but non-transfused patients 2.2% reported jaundice within 6 months of hospitalization. The risk of overt hepatitis from HB Ag in transfused blood is high in southern India and is similar to that in temperate countries where the occurrence of antigen carriers, and presumably of immune status, are lower than in the tropics. PMID:4549611

Co-stimulatory function in primary germinal center responses: CD40 and B7 are required on distinct antigen-presenting cells.

PubMed

Watanabe, Masashi; Fujihara, Chiharu; Radtke, Andrea J; Chiang, Y Jeffrey; Bhatia, Sumeena; Germain, Ronald N; Hodes, Richard J

2017-09-04

T cell-dependent germinal center (GC) responses require coordinated interactions of T cells with two antigen-presenting cell (APC) populations, B cells and dendritic cells (DCs), in the presence of B7- and CD40-dependent co-stimulatory pathways. Contrary to the prevailing paradigm, we found unique cellular requirements for B7 and CD40 expression in primary GC responses to vaccine immunization with protein antigen and adjuvant: B7 was required on DCs but was not required on B cells, whereas CD40 was required on B cells but not on DCs in the generation of antigen-specific follicular helper T cells, antigen-specific GC B cells, and high-affinity class-switched antibody production. There was, in fact, no requirement for coexpression of B7 and CD40 on the same cell in these responses. Our findings support a substantially revised model for co-stimulatory function in the primary GC response, with crucial and distinct contributions of B7- and CD40-dependent pathways expressed by different APC populations and with important implications for understanding how to optimize vaccine responses or limit autoimmunity. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

Censoring of self-reactive B cells by follicular dendritic cell-displayed self-antigen

PubMed Central

Yau, Irene W.; Cato, Matthew H.; Jellusova, Julia; Hurtado de Mendoza, Tatiana; Brink, Robert; Rickert, Robert C.

2013-01-01

In the secondary lymphoid organs, intimate contact with follicular dendritic cells (FDCs) is required for B cell retention and antigen-driven selection during the germinal center response. However, selection of self-reactive B cells by antigen on FDCs has not been addressed. To this end, we generated a mouse model to conditionally express a membrane-bound self-antigen on FDCs, and monitor the fate of developing self-reactive B cells. Here, we show that self-antigen displayed on FDCs mediates effective elimination of self-reactive B cells at the transitional stage. Notwithstanding, some self-reactive B cells persist beyond this checkpoint, showing evidence of antigen experience and intact proximal BCR signaling, but they are short-lived and unable to elicit T cell help. These results implicate FDCs as an important component of peripheral B cell tolerance that prevent the emergence of naïve B cells capable of responding to sequestered self-antigens. PMID:23817432

A Novel Protective Vaccine Antigen from the Core Escherichia coli Genome

PubMed Central

Moriel, Danilo G.; Tan, Lendl; Goh, Kelvin G. K.; Ipe, Deepak S.; Lo, Alvin W.; Peters, Kate M.

2016-01-01

ABSTRACT Escherichia coli is a versatile pathogen capable of causing intestinal and extraintestinal infections that result in a huge burden of global human disease. The diversity of E. coli is reflected by its multiple different pathotypes and mosaic genome composition. E. coli strains are also a major driver of antibiotic resistance, emphasizing the urgent need for new treatment and prevention measures. Here, we used a large data set comprising 1,700 draft and complete genomes to define the core and accessory genome of E. coli and demonstrated the overlapping relationship between strains from different pathotypes. In combination with proteomic investigation, this analysis revealed core genes that encode surface-exposed or secreted proteins that represent potential broad-coverage vaccine antigens. One of these antigens, YncE, was characterized as a conserved immunogenic antigen able to protect against acute systemic infection in mice after vaccination. Overall, this work provides a genomic blueprint for future analyses of conserved and accessory E. coli genes. The work also identified YncE as a novel antigen that could be exploited in the development of a vaccine against all pathogenic E. coli strains—an important direction given the high global incidence of infections caused by multidrug-resistant strains for which there are few effective antibiotics. IMPORTANCE E. coli is a multifaceted pathogen of major significance to global human health and an important contributor to increasing antibiotic resistance. Given the paucity of therapies still effective against multidrug-resistant pathogenic E. coli strains, novel treatment and prevention strategies are urgently required. In this study, we defined the core and accessory components of the E. coli genome by examining a large collection of draft and completely sequenced strains available from public databases. This data set was mined by employing a reverse-vaccinology approach in combination with proteomics

Recombinant protective antigen 102 (rPA102): profile of a second-generation anthrax vaccine.

PubMed

Keitel, Wendy A

2006-08-01

Recent terrorist attacks involving the use of Bacillus anthracis spores have stimulated interest in the development of new vaccines for anthrax prevention. Studies of the pathogenesis of anthrax and of the immune responses following infection and immunization underscore the pivotal role that antibodies to the protective antigen play in protection. The most promising vaccine candidates contain purified recombinant protective antigen. Clinical trials of one of these, recombinant protective antigen (rPA)102, are underway. Initial results suggest that rPA102 is well tolerated and immunogenic. Additional trials are necessary to identify optimal formulations and immunization regimens for pre- and postexposure prophylaxis. Future licensure of these and other candidate vaccines will depend on their safety and immunogenicity profiles in humans, and their ability to confer protection in animal models of inhalational anthrax.

Natural antibody response to Plasmodium falciparum merozoite antigens MSP5, MSP9 and EBA175 is associated to clinical protection in the Brazilian Amazon

PubMed Central

2013-01-01

Background Antibodies have an essential role in the acquired immune response against blood stage P. falciparum infection. Although several antigens have been identified as important antibody targets, it is still elusive which antigens have to be recognized for clinical protection. Herein, we analyzed antibodies from plasmas from symptomatic or asymptomatic individuals living in the same geographic area in the Western Amazon, measuring their recognition of multiple merozoite antigens. Methods Specific fragments of genes encoding merozoite proteins AMA1 and members of MSP and EBL families from circulating P. falciparum field isolates present in asymptomatic and symptomatic patients were amplified by PCR. After cloning and expression of different versions of the antigens as recombinant GST-fusion peptides, we tested the reactivity of patients’ plasmas by ELISA and the presence of IgG subclasses in the most reactive plasmas. Results 11 out of 24 recombinant antigens were recognized by plasmas from either symptomatic or asymptomatic infections. Antibodies to MSP9 (X2DF=1 = 9.26/p = 0.0047) and MSP5 (X2DF=1 = 8.29/p = 0.0069) were more prevalent in asymptomatic individuals whereas the opposite was observed for MSP1 block 2-MAD20 (X2DF=1 = 6.41/p = 0.0206, Fisher’s exact test). Plasmas from asymptomatic individuals reacted more intensely against MSP4 (U = 210.5, p < 0.03), MSP5 (U = 212, p < 0.004), MSP9 (U = 189.5, p < 0.002) and EBA175 (U = 197, p < 0.014, Mann-Whitney’s U test). IgG1 and IgG3 were predominant for all antigens, but some patients also presented with IgG2 and IgG4. The recognition of MSP5 (OR = 0.112, IC95% = 0.021-0.585) and MSP9 (OR = 0.125, IC95% = 0.030-0.529, cross tab analysis) predicted 8.9 and 8 times less chances, respectively, to present symptoms. Higher antibody levels against MSP5 and EBA175 were associated by odds ratios of 9.4 (IC95% = 1.29-69.25) and 5.7 (IC95

Hepatitis B virus DNA-positive, hepatitis B surface antigen-negative blood donations intercepted by anti-hepatitis B core antigen testing: the Canadian Blood Services experience.

PubMed

O'Brien, Sheila F; Fearon, Margaret A; Yi, Qi-Long; Fan, Wenli; Scalia, Vito; Muntz, Irene R; Vamvakas, Eleftherios C

2007-10-01

The benefit of introducing anti-hepatitis B core antigen (HBc) screening for intercepting potentially infectious donations missed by hepatitis B surface antigen (HBsAg) screening in Canada was studied. Anti-HBc testing of all donations was implemented in April 2005, along with antibody to hepatitis B surface antigen (anti-HBs) and hepatitis B virus (HBV) DNA supplemental testing of anti-HBc repeat-reactive, HBsAg-negative donations. The proportion of potentially infectious donations intercepted by anti-HBc over the initial 18 months of testing was calculated based on three assumptions relating infectivity of HBV DNA-positive units to anti-HBs levels. Lookback was conducted for all DNA-positive donations. Of 493,344 donors, 5,585 (1.13%) were repeat-reactive for the presence of anti-HBc, with 29 (0.52%) being HBV DNA-positive and HBsAg-negative. The proportion of potentially infectious donations intercepted by anti-HBc screening was 1 in 17,800 if all HBV DNA-positive donations were infectious, 1 in 26,900 if infectivity was limited to donations with an anti-HBs level of not more than 100 mIU per mL, and 1 in 69,300 if only donations with undetectable anti-HBs were infectious. For 279 components in the lookback study, no traced recipients were HBsAg-positive and 7 recipients were anti-HBc-reactive in association with 4 donors, 3 of whom had an anti-HBs level of more than 100 mIU per mL and 1 of whom had a level of 61 mIU per mL. Implementation of anti-HBc screening reduced the risk of transfusing potentially infectious units by at least as much as had been expected based on the literature. The lookback did not provide proof of transfusion transmission of HBV from HBV DNA-positive, anti-HBc-reactive, HBsAg-negative donors but it did not establish lack of transmission either.

O-mannosylation of the Mycobacterium tuberculosis Adhesin Apa Is Crucial for T Cell Antigenicity during Infection but Is Expendable for Protection

PubMed Central

Dobos, Karen M.; Lucas, Megan; Spencer, John S.; Fang, Sunan; McDonald, Melissa A.; Pohl, Jan; Birkness, Kristin; Chamcha, Venkateswarlu; Ramirez, Melissa V.; Plikaytis, Bonnie B.; Posey, James E.; Amara, Rama Rao

2013-01-01

Glycosylation is the most abundant post-translational polypeptide chain modification in nature. Although carbohydrate modification of protein antigens from many microbial pathogens constitutes important components of B cell epitopes, the role in T cell immunity is not completely understood. Here, using ELISPOT and polychromatic flow cytometry, we show that O-mannosylation of the adhesin, Apa, of Mycobacterium tuberculosis (Mtb) is crucial for its T cell antigenicity in humans and mice after infection. However, subunit vaccination with both mannosylated and non-mannosylated Apa induced a comparable magnitude and quality of T cell response and imparted similar levels of protection against Mtb challenge in mice. Both forms equally improved waning BCG vaccine-induced protection in elderly mice after subunit boosting. Thus, O-mannosylation of Apa is required for antigenicity but appears to be dispensable for its immunogenicity and protective efficacy in mice. These results have implications for the development of subunit vaccines using post-translationally modified proteins such as glycoproteins against infectious diseases like tuberculosis. PMID:24130497

O-mannosylation of the Mycobacterium tuberculosis adhesin Apa is crucial for T cell antigenicity during infection but is expendable for protection.

PubMed

Nandakumar, Subhadra; Kannanganat, Sunil; Dobos, Karen M; Lucas, Megan; Spencer, John S; Fang, Sunan; McDonald, Melissa A; Pohl, Jan; Birkness, Kristin; Chamcha, Venkateswarlu; Ramirez, Melissa V; Plikaytis, Bonnie B; Posey, James E; Amara, Rama Rao; Sable, Suraj B

2013-01-01

Glycosylation is the most abundant post-translational polypeptide chain modification in nature. Although carbohydrate modification of protein antigens from many microbial pathogens constitutes important components of B cell epitopes, the role in T cell immunity is not completely understood. Here, using ELISPOT and polychromatic flow cytometry, we show that O-mannosylation of the adhesin, Apa, of Mycobacterium tuberculosis (Mtb) is crucial for its T cell antigenicity in humans and mice after infection. However, subunit vaccination with both mannosylated and non-mannosylated Apa induced a comparable magnitude and quality of T cell response and imparted similar levels of protection against Mtb challenge in mice. Both forms equally improved waning BCG vaccine-induced protection in elderly mice after subunit boosting. Thus, O-mannosylation of Apa is required for antigenicity but appears to be dispensable for its immunogenicity and protective efficacy in mice. These results have implications for the development of subunit vaccines using post-translationally modified proteins such as glycoproteins against infectious diseases like tuberculosis.

Affinity of antigen encounter and other early B-cell signals determine B-cell fate

PubMed Central

Benson, Micah J; Erickson, Loren D; Gleeson, Michael W; Noelle, Randolph J

2010-01-01

Three possible effector fates await the naïve follicular B cell following antigen stimulation in thymus-dependent reactions. Short-lived plasma cells produce an initial burst of germline-encoded protective antibodies, and long-lived plasma cells and memory B cells arise from the germinal center and function to enhance and sustain the humoral immune response. The inherent B-cell receptor affinity of naïve follicular B cells and the contribution of other early B-cell signals pre-determines the pattern of transcription factor expression and the differentiation path taken by these cells. High initial B-cell receptor affinity shunts naïve follicular B-cell clones towards the short-lived plasma cell fate, whereas modest-affinity clones are skewed towards a plasma cell fate and low-affinity clones are recruited into the germinal center and are selected for both long-lived plasma cells and memory B cell pathways. In the germinal center reaction, increased levels of the transcription factor interferon regulatory factor-4 drive the molecular program that dictates differentiation into the long-lived plasma cell phenotype but has no impact on the memory B cell compartment. We hypothesize that graded interferon regulatory factor-4 levels driven by signals to B cells, including B-cell receptor signal strength, are responsible for this branch point in the B-cell terminal differentiation pathway. PMID:17433651

Novel Antigen Identification Method for Discovery of Protective Malaria Antigens by Rapid Testing of DNA Vaccines Encoding Exons from the Parasite Genome

PubMed Central

Haddad, Diana; Bilcikova, Erika; Witney, Adam A.; Carlton, Jane M.; White, Charles E.; Blair, Peter L.; Chattopadhyay, Rana; Russell, Joshua; Abot, Esteban; Charoenvit, Yupin; Aguiar, Joao C.; Carucci, Daniel J.; Weiss, Walter R.

2004-01-01

We describe a novel approach for identifying target antigens for preerythrocytic malaria vaccines. Our strategy is to rapidly test hundreds of DNA vaccines encoding exons from the Plasmodium yoelii yoelii genomic sequence. In this antigen identification method, we measure reduction in parasite burden in the liver after sporozoite challenge in mice. Orthologs of protective P. y. yoelii genes can then be identified in the genomic databases of Plasmodium falciparum and Plasmodium vivax and investigated as candidate antigens for a human vaccine. A pilot study to develop the antigen identification method approach used 192 P. y. yoelii exons from genes expressed during the sporozoite stage of the life cycle. A total of 182 (94%) exons were successfully cloned into a DNA immunization vector with the Gateway cloning technology. To assess immunization strategies, mice were vaccinated with 19 of the new DNA plasmids in addition to the well-characterized protective plasmid encoding P. y. yoelii circumsporozoite protein. Single plasmid immunization by gene gun identified a novel vaccine target antigen which decreased liver parasite burden by 95% and which has orthologs in P. vivax and P. knowlesi but not P. falciparum. Intramuscular injection of DNA plasmids produced a different pattern of protective responses from those seen with gene gun immunization. Intramuscular immunization with plasmid pools could reduce liver parasite burden in mice despite the fact that none of the plasmids was protective when given individually. We conclude that high-throughput cloning of exons into DNA vaccines and their screening is feasible and can rapidly identify new malaria vaccine candidate antigens. PMID:14977966

Deletion and anergy of polyclonal B cells specific for ubiquitous membrane-bound self-antigen

PubMed Central

Taylor, Justin J.; Martinez, Ryan J.; Titcombe, Philip J.; Barsness, Laura O.; Thomas, Stephanie R.; Zhang, Na; Katzman, Shoshana D.; Jenkins, Marc K.

2012-01-01

B cell tolerance to self-antigen is critical to preventing antibody-mediated autoimmunity. Previous work using B cell antigen receptor transgenic animals suggested that self-antigen–specific B cells are either deleted from the repertoire, enter a state of diminished function termed anergy, or are ignorant to the presence of self-antigen. These mechanisms have not been assessed in a normal polyclonal repertoire because of an inability to detect rare antigen-specific B cells. Using a novel detection and enrichment strategy to assess polyclonal self-antigen–specific B cells, we find no evidence of deletion or anergy of cells specific for antigen not bound to membrane, and tolerance to these types of antigens appears to be largely maintained by the absence of T cell help. In contrast, a combination of deleting cells expressing receptors with high affinity for antigen with anergy of the undeleted lower affinity cells maintains tolerance to ubiquitous membrane-bound self-antigens. PMID:23071255

Characterization of MHC-II antigen presentation by B cells and monocytes from older individuals

PubMed Central

HL, Clark; R, Banks; L, Jones; TR, Hornick; PA, Higgins; CJ, Burant; DH, Canaday

2012-01-01

In this study we examine the effects of aging on antigen presentation of B cells and monocytes. We compared the antigen presentation function of peripheral blood B cells from young and old subjects using a system that specifically measures the B cell receptor (BCR)-mediated MHC-II antigen presentation. Monocytes were studied as well. Overall the mean magnitude of antigen presentation of soluble antigen and peptide was not different in older and younger subjects for both B cells and monocytes. Older subjects, however, showed increased heterogeneity of BCR-mediated antigen presentation by their B cells. The magnitude and variability of peptide presentation, which does not require uptake and processing, was the same between groups. Presentation by monocytes had similar variability between the older and younger subjects. These data suggest that poor B cell antigen processing, which results in diminished presentation in some older individuals may contribute to poor vaccine responses. PMID:22797466

Partial purification and characterization of protection-inducing antigens from the muscle larva of Trichinella spiralis by molecular sizing chromatography and preparative flatbed isoelectric focusing.

PubMed

Despommier, D D

1981-01-01

The soluble portion of a large particle fraction which was derived from the muscle larva of T. spiralis was subjected to molecular sizing column chromatography using Sephacryl S-200. Five major peaks of 280 nm absorbing material were obtained. Analysis by immunoelectrophoresis revealed that each peak contained antigens, with the majority of them occurring in peaks 3, 4 and 5. Preliminary studies indicated that peak 4(mol. wt range 20 000--10 000) contained protection-inducing antigens. Crossed-immunoelectrophoretic and single-dimension electrophoretic analysis of peak 4 revealed a minimum of 10 antigens, while analytical isoelectric focusing demonstrated the presence of proteins with widely different pl, ranging from 4.0 to 9.0. Peak 4 was fractionated by preparative flatbed isoelectric focusing (PIEF) using two gradients: one from 3.5 to 9.5 and the other from 3.5 to 5.5. Fused rocket immunoelectrophoretic (FRIEP) analysis of both runs indicated that several antigens were separated from the others: one at pl 4.0 and the other at pl 9.0. The remaining antigens focused between pl 4.3 and 4.9. One hundred micrograms of whole peak 4, pl 9.0 antigen and the group of antigens at pl 4.3--4.9 were each separately injected, along with Freund's complete adjuvant, into mice. In addition, a portion of the pl 4.0 antigen was also assayed for protection. All antigenic preparations induced significant levels of protection. The pl 4.0 was further analysed on high-performance liquid chromatography (HPLC). Two sharp peaks of antigen, as detected by FRIEP, were eluted isocratically with 65% acetonitrile from a C-18 (aliphatic) column. Both peaks of antigen showed complete cross-reactivity on FRIEP and absorbed at 220 nm. Amino acid analysis of each HPLC peak revealed no detectable differences in composition. Each peak contained predominance of aspartic (13 mol%) and glutamic (18 mol%) acid. This antigen did not contain significant quantities of aromatic amino acids, and absorbed

Antigen Availability Shapes T Cell Differentiation and Function during Tuberculosis.

PubMed

Moguche, Albanus O; Musvosvi, Munyaradzi; Penn-Nicholson, Adam; Plumlee, Courtney R; Mearns, Helen; Geldenhuys, Hennie; Smit, Erica; Abrahams, Deborah; Rozot, Virginie; Dintwe, One; Hoff, Søren T; Kromann, Ingrid; Ruhwald, Morten; Bang, Peter; Larson, Ryan P; Shafiani, Shahin; Ma, Shuyi; Sherman, David R; Sette, Alessandro; Lindestam Arlehamn, Cecilia S; McKinney, Denise M; Maecker, Holden; Hanekom, Willem A; Hatherill, Mark; Andersen, Peter; Scriba, Thomas J; Urdahl, Kevin B

2017-06-14

CD4 T cells are critical for protective immunity against Mycobacterium tuberculosis (Mtb), the cause of tuberculosis (TB). Yet to date, TB vaccine candidates that boost antigen-specific CD4 T cells have conferred little or no protection. Here we examined CD4 T cell responses to two leading TB vaccine antigens, ESAT-6 and Ag85B, in Mtb-infected mice and in vaccinated humans with and without underlying Mtb infection. In both species, Mtb infection drove ESAT-6-specific T cells to be more differentiated than Ag85B-specific T cells. The ability of each T cell population to control Mtb in the lungs of mice was restricted for opposite reasons: Ag85B-specific T cells were limited by reduced antigen expression during persistent infection, whereas ESAT-6-specific T cells became functionally exhausted due to chronic antigenic stimulation. Our findings suggest that different vaccination strategies will be required to optimize protection mediated by T cells recognizing antigens expressed at distinct stages of Mtb infection. Copyright © 2017 Elsevier Inc. All rights reserved.

Thermostable cross-protective subunit vaccine against Brucella species.

PubMed

Cherwonogrodzky, John W; Barabé, Nicole D; Grigat, Michelle L; Lee, William E; Poirier, Robert T; Jager, Scott J; Berger, Bradley J

2014-12-01

A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 × 10(5) CFU), and a single injection of 1 μg of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Human Parvovirus B19 Induced Apoptotic Bodies Contain Altered Self-Antigens that are Phagocytosed by Antigen Presenting Cells

PubMed Central

Thammasri, Kanoktip; Rauhamäki, Sanna; Wang, Liping; Filippou, Artemis; Kivovich, Violetta; Marjomäki, Varpu; Naides, Stanley J.; Gilbert, Leona

2013-01-01

Human parvovirus B19 (B19V) from the erythrovirus genus is known to be a pathogenic virus in humans. Prevalence of B19V infection has been reported worldwide in all seasons, with a high incidence in the spring. B19V is responsible for erythema infectiosum (fifth disease) commonly seen in children. Its other clinical presentations include arthralgia, arthritis, transient aplastic crisis, chronic anemia, congenital anemia, and hydrops fetalis. In addition, B19V infection has been reported to trigger autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. However, the mechanisms of B19V participation in autoimmunity are not fully understood. B19V induced chronic disease and persistent infection suggests B19V can serve as a model for viral host interactions and the role of viruses in the pathogenesis of autoimmune diseases. Here we investigate the involvement of B19V in the breakdown of immune tolerance. Previously, we demonstrated that the non-structural protein 1 (NS 1) of B19V induces apoptosis in non-permissive cells lines and that this protein can cleave host DNA as well as form NS1-DNA adducts. Here we provide evidence that through programmed cell death, apoptotic bodies (ApoBods) are generated by B19V NS1 expression in a non-permissive cell line. Characterization of purified ApoBods identified potential self-antigens within them. In particular, signature self-antigens such as Smith, ApoH, DNA, histone H4 and phosphatidylserine associated with autoimmunity were present in these ApoBods. In addition, when purified ApoBods were introduced to differentiated macrophages, recognition, engulfment and uptake occurred. This suggests that B19V can produce a source of self-antigens for immune cell processing. The results support our hypothesis that B19V NS1-DNA adducts, and nucleosomal and lysosomal antigens present in ApoBods created in non-permissive cell lines, are a source of self-antigens. PMID:23776709

A Longitudinal Hepatitis B Vaccine Cohort Demonstrates Long-lasting Hepatitis B Virus (HBV) Cellular Immunity Despite Loss of Antibody Against HBV Surface Antigen

PubMed Central

Simons, Brenna C.; Spradling, Philip R.; Bruden, Dana J. T.; Zanis, Carolyn; Case, Samantha; Choromanski, Tammy L.; Apodaca, Minjun; Brogdon, Hazel D.; Dwyer, Gaelen; Snowball, Mary; Negus, Susan; Bruce, Michael G.; Morishima, Chihiro; Knall, Cindy; McMahon, Brian J.

2016-01-01

Background. Long-lasting protection resulting from hepatitis B vaccine, despite loss of antibody against hepatitis B virus (HBV) surface antigen (anti-HBs), is undetermined. Methods. We recruited persons from a cohort vaccinated with plasma-derived hepatitis B vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array. Study subgroups were defined 32 years after vaccination as having an anti-HBs level of either ≥10 mIU/mL (group 1; n = 13) or <10 mIU/mL (group 2; n = 31). Results. All 44 participants, regardless of anti-HBs level, tested positive for tumor necrosis factor α, interleukin 10, or interleukin 6 production by HBV surface antigen–specific T cells. The frequency of natural killer T cells correlated with the level of anti-HBs (P = .008). The proportion of participants who demonstrated T-cell responses to HBV core antigen varied among the cytokines measured, suggesting some natural exposure to HBV in the study group. No participant had evidence of breakthrough HBV infection. Conclusions. Evidence of long-lasting cellular immunity, regardless of anti-HBs level, suggests that protection afforded by primary immunization with plasma-derived hepatitis B vaccine during childhood and adulthood lasts at least 32 years. PMID:27056956

Cross-protection among lethal H5N2 influenza viruses induced by DNA vaccine to the hemagglutinin.

PubMed Central

Kodihalli, S; Haynes, J R; Robinson, H L; Webster, R G

1997-01-01

Inoculation of mice with hemagglutinin (HA)-expressing DNA affords reliable protection against lethal influenza virus infection, while in chickens the same strategy has yielded variable results. Here we show that gene gun delivery of DNA encoding an H5 HA protein confers complete immune protection to chickens challenged with lethal H5 viruses. In tests of the influence of promoter selection on vaccine efficacy, close correlations were obtained between immune responses and the dose of DNA administered, whether a cytomegalovirus (CMV) immediate-early promoter or a chicken beta-actin promoter was used. Perhaps most important, the HA-DNA vaccine conferred 95% cross-protection against challenge with lethal antigenic variants that differed from the primary antigen by 11 to 13% (HA1 amino acid sequence homology). Overall, the high levels of protection seen with gene gun delivery of HA-DNA were as good as, if not better than, those achieved with a conventional whole-virus vaccine, with fewer instances of morbidity and death. The absence of detectable antibody titers after primary immunization, together with the rapid appearance of high titers immediately after challenge, implicates efficient B-cell priming as the principal mechanism of DNA-mediated immune protection. Our results suggest that the efficacy of HA-DNA influenza virus vaccine in mice extends to chickens and probably to other avian species as well. Indeed, the H5 preparation we describe offers an attractive means to protect the domestic poultry industry in the United States from lethal H5N2 viruses, which continue to circulate in Mexico. PMID:9094608

Mycobacterium tuberculosis multistage antigens confer comprehensive protection against pre- and post-exposure infections by driving Th1-type T cell immunity

PubMed Central

Fan, Xionglin; Yu, Qi; Jing, Yukai; Wang, Weihua; Li, Li; Zhou, Zijie

2016-01-01

There is an urgent need for a vaccine against tuberculosis (TB) that is more effective than the current sole licensed option. However, target antigens of Mycobacterium tuberculosis with the vaccine potential remain elusive. Five immunodominant antigens with characteristic expressions at the stages of primary infection (Ag85A), the regulation of nutrition and metabolism when transferring from rapid growth to latency (PhoY2 and Rv3407), latency (Rv2626c), and reactivation (RpfB) were selected to construct the fusion polyprotein WH121, which has better immunogenicity and protection than each multistage antigen. DMT adjuvanted WH121 vaccinated C57BL/6 mice could confer persistent and significant protection against the respiratory challenge with 80 CFU of virulent M. tuberculosis H37Rv at 9 and 18 weeks after immunization, as the BCG vaccine did. Moreover, WH121/DMT could boost the BCG primed mice against post-exposure infection, and more significantly inhibit the growth of M. tuberculosis in the spleen than BCG repeat vaccination. The protection elicited by WH121/DMT is attributed to the WH121-specific Th1-type biased immune responses, characterized by increased antigen-specific IgG2a/IgG1 ratio and high levels of IFN-γ secreted by the splenocytes of vaccinated mice. In particular, high levels of IFN-γ+ TEM cells in the spleen are an effective biomarker for the vaccine-induced early protection, and the persistent protection mainly depends on the increasing IL-2+IFN-γ+CD4+ and CD8+ T cells, especially IL-2+ TCM cells. These findings demonstrate that multistage-specific antigens might be promising targets for the next generation TB vaccine, and a combination of these antigens such as WH121/DMT is required for further preclinical evaluation. PMID:27566581

Cell-mediated immune response and Th/Th cytokine profile of B-T constructs of F1 and V antigen of Yersinia pestis.

PubMed

Gupta, G; Khan, A A; Rao, D N

2010-03-01

Yersinia pestis, a Gram-negative bacterium, is the etiological agent of pneumonic and bubonic plague and still active in various regions of the world. Because plague is highly infectious and can readily spread by aerosolization, it poses a bioterrorism threat. The effective induction of mucosal as well as systemic immunity is an important attribute of an improved vaccine for plague. An alternative approach described here is the use of protective epitopes derived from immunodominant antigens (F1 and V) of Yersinia pestis. As T-cell immunity is also a major contributor of protection, microencapsulated B-T constructs of F1 and V antigen were used to immunize outbred and inbred mice through intranasal route, and lympho-proliferative response and cytokine profile of both Th(1) and Th(2) arms were measured in spleen, lamina propria and Peyer's patches. Three B-T constructs of F1 antigen and seven of V antigen showed significantly high T-cell response in terms of inducing systemic as well as mucosal response when compared to constituent peptides. These ten conjugates showed Th(1) cytokine profile whereas rest of the conjugates showed mixed Th(1)/Th(2) response. Four conjugates of V antigen showed high level of IL-10 production. In present study, microencapsulated B-T constructs after intranasal immunization generated systemic as well as mucosal immune response in all three sites, which offers an alternative approach for plague vaccine.

Sialylated multivalent antigens engage CD22 in trans and inhibit B cell activation.

PubMed

Courtney, Adam H; Puffer, Erik B; Pontrello, Jason K; Yang, Zhi-Qiang; Kiessling, Laura L

2009-02-24

CD22 is an inhibitory coreceptor on the surface of B cells that attenuates B cell antigen receptor (BCR) signaling and, therefore, B cell activation. Elucidating the molecular mechanisms underlying the inhibitory activity of CD22 is complicated by the ubiquity of CD22 ligands. Although antigens can display CD22 ligands, the receptor is known to bind to sialylated glycoproteins on the cell surface. The propinquity of CD22 and cell-surface glycoprotein ligands has led to the conclusion that the inhibitory properties of the receptor are due to cis interactions. Here, we examine the functional consequences of trans interactions by employing sialylated multivalent antigens that can engage both CD22 and the BCR. Exposure of B cells to sialylated antigens results in the inhibition of key steps in BCR signaling. These results reveal that antigens bearing CD22 ligands are powerful suppressors of B cell activation. The ability of sialylated antigens to inhibit BCR signaling through trans CD22 interactions reveals a previously unrecognized role for the Siglec-family of receptors as modulators of immune signaling.

HLA class I antigen and HLA-A, -B, and -C haplotype frequencies in Uruguayans.

PubMed

Alvarez, Ines; Bengochea, Milka; Toledo, Roberto; Carretto, Elena; Hidalgo, Pedro C

2006-08-01

HLA class I antigens were determined for 959 unrelated Uruguayans. The predominant HLA alleles were A2, Cw4, and B35, and the most frequently observed two-loci haplotypes were A2-B44 and B35-Cw4. The most frequent three-loci HLA haplotype was A2-Cw5-B44. We compared the Uruguayan sample with similar data from other populations.

B-Cell Responses to Pregnancy-Restricted and -Unrestricted Plasmodium falciparum Erythrocyte Membrane Protein 1 Antigens in Ghanaian Women Naturally Exposed to Malaria Parasites

PubMed Central

Ampomah, Paulina; Stevenson, Liz; Ofori, Michael F.; Barfod, Lea

2014-01-01

Protective immunity to Plasmodium falciparum malaria acquired after natural exposure is largely antibody mediated. IgG-specific P. falciparum EMP1 (PfEMP1) proteins on the infected erythrocyte surface are particularly important. The transient antibody responses and the slowly acquired protective immunity probably reflect the clonal antigenic variation and allelic polymorphism of PfEMP1. However, it is likely that other immune-evasive mechanisms are also involved, such as interference with formation and maintenance of immunological memory. We measured PfEMP1-specific antibody levels by enzyme-linked immunosorbent assay (ELISA) and memory B-cell frequencies by enzyme-linked immunosorbent spot (ELISPOT) assay in a cohort of P. falciparum-exposed nonpregnant Ghanaian women. The antigens used were a VAR2CSA-type PfEMP1 (IT4VAR04) with expression restricted to parasites infecting the placenta, as well as two commonly recognized PfEMP1 proteins (HB3VAR06 and IT4VAR60) implicated in rosetting and not pregnancy restricted. This enabled, for the first time, a direct comparison in the same individuals of immune responses specific for a clinically important parasite antigen expressed only during well-defined periods (pregnancy) to responses specific for comparable antigens expressed independent of pregnancy. Our data indicate that PfEMP1-specific B-cell memory is adequately acquired even when antigen exposure is infrequent (e.g., VAR2CSA-type PfEMP1). Furthermore, immunological memory specific for VAR2CSA-type PfEMP1 can be maintained for many years without antigen reexposure and after circulating antigen-specific IgG has disappeared. The study provides evidence that natural exposure to P. falciparum leads to formation of durable B-cell immunity to clinically important PfEMP1 antigens. This has encouraging implications for current efforts to develop PfEMP1-based vaccines. PMID:24566620

Advax-Adjuvanted Recombinant Protective Antigen Provides Protection against Inhalational Anthrax That Is Further Enhanced by Addition of Murabutide Adjuvant

PubMed Central

Feinen, Brandon; Petrovsky, Nikolai; Verma, Anita

2014-01-01

Subunit vaccines against anthrax based on recombinant protective antigen (PA) potentially offer more consistent and less reactogenic anthrax vaccines but require adjuvants to achieve optimal immunogenicity. This study sought to determine in a murine model of pulmonary anthrax infection whether the polysaccharide adjuvant Advax or the innate immune adjuvant murabutide alone or together could enhance PA immunogenicity by comparison to an alum adjuvant. A single immunization with PA plus Advax adjuvant afforded significantly greater protection against aerosolized Bacillus anthracis Sterne strain 7702 than three immunizations with PA alone. Murabutide had a weaker adjuvant effect than Advax when used alone, but when murabutide was formulated together with Advax, an additive effect on immunogenicity and protection was observed, with complete protection after just two doses. The combined adjuvant formulation stimulated a robust, long-lasting B-cell memory response that protected mice against an aerosol challenge 18 months postimmunization with acceleration of the kinetics of the anamnestic IgG response to B. anthracis as reflected by ∼4-fold-higher anti-PA IgG titers by day 2 postchallenge versus mice that received PA with Alhydrogel. In addition, the combination of Advax plus murabutide induced approximately 3-fold-less inflammation than Alhydrogel as measured by in vivo imaging of cathepsin cleavage resulting from injection of ProSense 750. Thus, the combination of Advax and murabutide provided enhanced protection against inhalational anthrax with reduced localized inflammation, making this a promising next-generation anthrax vaccine adjuvanting strategy. PMID:24554695

Advax-adjuvanted recombinant protective antigen provides protection against inhalational anthrax that is further enhanced by addition of murabutide adjuvant.

PubMed

Feinen, Brandon; Petrovsky, Nikolai; Verma, Anita; Merkel, Tod J

2014-04-01

Subunit vaccines against anthrax based on recombinant protective antigen (PA) potentially offer more consistent and less reactogenic anthrax vaccines but require adjuvants to achieve optimal immunogenicity. This study sought to determine in a murine model of pulmonary anthrax infection whether the polysaccharide adjuvant Advax or the innate immune adjuvant murabutide alone or together could enhance PA immunogenicity by comparison to an alum adjuvant. A single immunization with PA plus Advax adjuvant afforded significantly greater protection against aerosolized Bacillus anthracis Sterne strain 7702 than three immunizations with PA alone. Murabutide had a weaker adjuvant effect than Advax when used alone, but when murabutide was formulated together with Advax, an additive effect on immunogenicity and protection was observed, with complete protection after just two doses. The combined adjuvant formulation stimulated a robust, long-lasting B-cell memory response that protected mice against an aerosol challenge 18 months postimmunization with acceleration of the kinetics of the anamnestic IgG response to B. anthracis as reflected by ∼4-fold-higher anti-PA IgG titers by day 2 postchallenge versus mice that received PA with Alhydrogel. In addition, the combination of Advax plus murabutide induced approximately 3-fold-less inflammation than Alhydrogel as measured by in vivo imaging of cathepsin cleavage resulting from injection of ProSense 750. Thus, the combination of Advax and murabutide provided enhanced protection against inhalational anthrax with reduced localized inflammation, making this a promising next-generation anthrax vaccine adjuvanting strategy.

Parvovirus B19 empty capsids as antigen carriers for presentation of antigenic determinants of dengue 2 virus.

PubMed

Amexis, Georgios; Young, Neal S

2006-09-15

For the production of dengue-vaccine candidates, empty capsids, or virus-like particles (VLPs), of parvovirus B19 that carry dengue 2-specific epitopes were employed as antigen carriers. Two epitopes (comprising amino acids 352-368 and 386-397) of domain BIII of the envelope glycoprotein were chosen to produce recombinant B19 VLPs for immunization of BALB/c mice. Serum samples from immunized mice revealed that recombinant B19 VLPs elicited strong humoral immune responses. In summary, this B19 VLP-vaccine platform produced high (> or =2.0 x 10(5)) anti-dengue 2 titers and robust (< or =1 120) 50%-plaque-reduction neutralization test (PRNT(50)) titers, which effectively neutralized live dengue 2 virus in PRNT(50) assays.

Antigen-B Cell Receptor Complexes Associate with Intracellular major histocompatibility complex (MHC) Class II Molecules*

PubMed Central

Barroso, Margarida; Tucker, Heidi; Drake, Lisa; Nichol, Kathleen; Drake, James R.

2015-01-01

Antigen processing and MHC class II-restricted antigen presentation by antigen-presenting cells such as dendritic cells and B cells allows the activation of naïve CD4+ T cells and cognate interactions between B cells and effector CD4+ T cells, respectively. B cells are unique among class II-restricted antigen-presenting cells in that they have a clonally restricted antigen-specific receptor, the B cell receptor (BCR), which allows the cell to recognize and respond to trace amounts of foreign antigen present in a sea of self-antigens. Moreover, engagement of peptide-class II complexes formed via BCR-mediated processing of cognate antigen has been shown to result in a unique pattern of B cell activation. Using a combined biochemical and imaging/FRET approach, we establish that internalized antigen-BCR complexes associate with intracellular class II molecules. We demonstrate that the M1-paired MHC class II conformer, shown previously to be critical for CD4 T cell activation, is incorporated selectively into these complexes and loaded selectively with peptide derived from BCR-internalized cognate antigen. These results demonstrate that, in B cells, internalized antigen-BCR complexes associate with intracellular MHC class II molecules, potentially defining a site of class II peptide acquisition, and reveal a selective role for the M1-paired class II conformer in the presentation of cognate antigen. These findings provide key insights into the molecular mechanisms used by B cells to control the source of peptides charged onto class II molecules, allowing the immune system to mount an antibody response focused on BCR-reactive cognate antigen. PMID:26400081

Schistosoma mansoni Infection Can Jeopardize the Duration of Protective Levels of Antibody Responses to Immunizations against Hepatitis B and Tetanus Toxoid.

PubMed

Riner, Diana K; Ndombi, Eric M; Carter, Jennifer M; Omondi, Amos; Kittur, Nupur; Kavere, Emmy; Korir, Harrison K; Flaherty, Briana; Karanja, Diana; Colley, Daniel G

2016-12-01

Schistosomiasis is a disease of major public health importance in sub-Saharan Africa. Immunoregulation begins early in schistosome infection and is characterized by hyporesponsiveness to parasite and bystander antigens, suggesting that a schistosome infection at the time of immunization could negatively impact the induction of protective vaccine responses. This study examined whether having a Schistosoma mansoni infection at the time of immunization with hepatitis B and tetanus toxoid (TT) vaccines impacts an individual's ability to achieve and maintain protective antibody levels against hepatitis B surface antigen or TT. Adults were recruited from Kisumu Polytechnic College in Western Kenya. At enrollment, participants were screened for schistosomiasis and soil transmitted helminths (STHs) and assigned to groups based on helminth status. The vaccines were then administered and helminth infections treated a week after the first hepatitis B boost. Over an 8 month period, 3 blood specimens were obtained for the evaluation of humoral and cytokine responses to the vaccine antigens and for immunophenotyping. 146 individuals were available for final analysis and 26% were S. mansoni positive (Sm+). Schistosomiasis did not impede the generation of initial minimum protective antibody levels to either hepatitis B or TT vaccines. However, median hepatitis B surface antibody levels were significantly lower in the Sm+ group after the first boost and remained lower, but not significantly lower, following praziquantel (PZQ) treatment and final boost. In addition, 8 months following TT boost and 7 months following PZQ treatment, Sm+ individuals were more likely to have anti-TT antibody levels fall below levels considered optimal for long term protection. IL-5 levels in response to in vitro TT stimulation of whole blood were significantly higher in the Sm+ group at the 8 month time period as well. Individuals with schistosomiasis at the start the immunizations were capable of

Schistosoma mansoni Infection Can Jeopardize the Duration of Protective Levels of Antibody Responses to Immunizations against Hepatitis B and Tetanus Toxoid

PubMed Central

Riner, Diana K.; Ndombi, Eric M.; Carter, Jennifer M.; Omondi, Amos; Kittur, Nupur; Kavere, Emmy; Korir, Harrison K.; Flaherty, Briana; Karanja, Diana; Colley, Daniel G.

2016-01-01

Background Schistosomiasis is a disease of major public health importance in sub-Saharan Africa. Immunoregulation begins early in schistosome infection and is characterized by hyporesponsiveness to parasite and bystander antigens, suggesting that a schistosome infection at the time of immunization could negatively impact the induction of protective vaccine responses. This study examined whether having a Schistosoma mansoni infection at the time of immunization with hepatitis B and tetanus toxoid (TT) vaccines impacts an individual’s ability to achieve and maintain protective antibody levels against hepatitis B surface antigen or TT. Methods Adults were recruited from Kisumu Polytechnic College in Western Kenya. At enrollment, participants were screened for schistosomiasis and soil transmitted helminths (STHs) and assigned to groups based on helminth status. The vaccines were then administered and helminth infections treated a week after the first hepatitis B boost. Over an 8 month period, 3 blood specimens were obtained for the evaluation of humoral and cytokine responses to the vaccine antigens and for immunophenotyping. Results 146 individuals were available for final analysis and 26% were S. mansoni positive (Sm+). Schistosomiasis did not impede the generation of initial minimum protective antibody levels to either hepatitis B or TT vaccines. However, median hepatitis B surface antibody levels were significantly lower in the Sm+ group after the first boost and remained lower, but not significantly lower, following praziquantel (PZQ) treatment and final boost. In addition, 8 months following TT boost and 7 months following PZQ treatment, Sm+ individuals were more likely to have anti-TT antibody levels fall below levels considered optimal for long term protection. IL-5 levels in response to in vitro TT stimulation of whole blood were significantly higher in the Sm+ group at the 8 month time period as well. Conclusions Individuals with schistosomiasis at the

Utilization of a photoactivatable antigen system to examine B-cell probing termination and the B-cell receptor sorting mechanisms during B-cell activation

PubMed Central

Wang, Jing; Tang, Shan; Wan, Zhengpeng; Gao, Yiren; Cao, Yiyun; Yi, Junyang; Si, Yanyan; Zhang, Haowen; Liu, Lei; Liu, Wanli

2016-01-01

Antigen binding to the B-cell receptor (BCR) induces several responses, resulting in B-cell activation, proliferation, and differentiation. However, it has been difficult to study these responses due to their dynamic, fast, and transient nature. Here, we attempted to solve this problem by developing a controllable trigger point for BCR and antigen recognition through the construction of a photoactivatable antigen, caged 4-hydroxy-3-nitrophenyl acetyl (caged-NP). This photoactivatable antigen system in combination with live cell and single molecule imaging techniques enabled us to illuminate the previously unidentified B-cell probing termination behaviors and the precise BCR sorting mechanisms during B-cell activation. B cells in contact with caged-NP exhibited probing behaviors as defined by the unceasing extension of membrane pseudopods in random directions. Further analyses showed that such probing behaviors are cell intrinsic with strict dependence on F-actin remodeling but not on tonic BCR signaling. B-cell probing behaviors were terminated within 4 s after photoactivation, suggesting that this response was sensitive and specific to BCR engagement. The termination of B-cell probing was concomitant with the accumulation response of the BCRs into the BCR microclusters. We also determined the Brownian diffusion coefficient of BCRs from the same B cells before and after BCR engagement. The analysis of temporally segregated single molecule images of both BCR and major histocompatibility complex class I (MHC-I) demonstrated that antigen binding induced trapping of BCRs into the BCR microclusters is a fundamental mechanism for B cells to acquire antigens. PMID:26764382

HLA-B27 and antigen presentation: at the crossroads between immune defense and autoimmunity.

PubMed

Sorrentino, Rosa; Böckmann, Rainer A; Fiorillo, Maria Teresa

2014-01-01

The HLA-B27 is historically studied as a susceptibility factor in spondyloarthropathies and, primarily, in ankylosing spondylitis (AS). Over the recent years however, it has been rediscovered as protective factor against some severe viral infections. This is due to the high capacity of virus-specific, HLA-B27-restricted CD8+ T cells for both intrinsic (i.e. polyfunctionality, high avidity, low sensitivity to Treg cell-mediated suppression) and extrinsic (i.e. rapid and efficient antigen processing and presentation) factors. It is tempting to speculate that these two aspects are not independent and that the association of B27 molecules to autoimmunity is the downside of this superior functional efficacy which, in given genetic backgrounds and environmental conditions, can support a chronic inflammation leading to spondyloarthropathies. Still, the pathogenic role of HLA-B27 molecules in AS is elusive. Here, we focus on the biology of HLA-B27 from the genetics to the biochemistry and to the structural/dynamical properties of B27:peptide complexes as obtained from atomistic molecular dynamics simulation. Overall, the results point at the antigen presentation as the key event in the disease pathogenesis. In particular, an extensive comparison of HLA-B*2705 and B*2709 molecules, that differ in a single amino acid (Asp116 to His116) and are differentially associated with AS, indicates that position 116 is crucial for shaping the entire peptide-presenting groove. Copyright © 2013 Elsevier Ltd. All rights reserved.

Immunological Properties of Hepatitis B Core Antigen Fusion Proteins

NASA Astrophysics Data System (ADS)

Francis, Michael J.; Hastings, Gillian Z.; Brown, Alan L.; Grace, Ken G.; Rowlands, David J.; Brown, Fred; Clarke, Berwyn E.

1990-04-01

The immunogenicity of a 19 amino acid peptide from foot-and-mouth disease virus has previously been shown to approach that of the inactivated virus from which it was derived after multimeric particulate presentation as an N-terminal fusion with hepatitis B core antigen. In this report we demonstrate that rhinovirus peptide-hepatitis B core antigen fusion proteins are 10-fold more immunogenic than peptide coupled to keyhole limpet hemocyanin and 100-fold more immunogenic than uncoupled peptide with an added helper T-cell epitope. The fusion proteins can be readily administered without adjuvant or with adjuvants acceptable for human and veterinary application and can elicit a response after nasal or oral dosing. The fusion proteins can also act as T-cell-independent antigens. These properties provide further support for their suitability as presentation systems for "foreign" epitopes in the development of vaccines.

Purification and Protective Efficacy of Monomeric and Modified Yersina pestis Capsular F1-V Antigen Fusion Proteins for Vaccination Against Plague

DTIC Science & Technology

2006-12-31

Yersinia pestis capsular F1-V antigen fusion proteins for vaccination against plague Jeremy L. Goodin a,1, David F. Nellis b,1, Bradford S. Powell a, Vinay...USA Received 4 October 2006, and in revised form 19 December 2006 Available online 31 December 2006Abstract The F1-V vaccine antigen, protective...After a two-dose vaccination with 2 · 20 lg of F1-V, respec- tively, 100%, 80%, 80%, and 70% of injected mice survived a subcutaneous lethal plague

Prognostic significance of 5T4 oncofetal antigen expression in colorectal carcinoma.

PubMed Central

Starzynska, T.; Marsh, P. J.; Schofield, P. F.; Roberts, S. A.; Myers, K. A.; Stern, P. L.

1994-01-01

The 5T4 oncofetal antigen is a 72 kDa glycoprotein defined by a monoclonal antibody raised against human placental trophoblast and is expressed in many different carcinomas but detected only at low levels in some normal epithelia. Immunohistochemical analysis of the patterns of expression in colorectal carcinomas has indicated a significant association between the presence of the antigen in tumour cells and metastatic spread. The 5T4 antigen phenotype of 72 colorectal cancers has been compared with the clinical outcome of the patients in order to assess its relationship with prognosis. Forty per cent of tumours were 5T4 positive; the remainder were either unlabelled or exhibited stroma-associated labelling only. There was a significant correlation between 5T4 expression in the malignant cells and unfavourable course of disease (P < 0.001). The 5 year survival with 5T4-positive tumours was 22% compared with 75% for patients with 5T4-negative tumours; median survival was 24 versus > 90 months respectively. Stratified analysis showed that 5T4 antigen tumour positivity was acting independently of each of stage, site of tumour, age or sex. There were significant differences in survival for patients with Dukes' B and C stage carcinomas (P = 0.001 and P = 0.034). The results suggest that in colorectal cancer immunohistochemical assessment of 5T4 expression may be useful in identifying patients at high risk for tumour recurrence and for whom additional treatment strategies might be most appropriate. Images Figure 1 PMID:8180020

Novel Antigen Identification Method for Discovery of Protective Malaria Antigens by Rapid Testing of DNA Vaccines Encoding Exons from the Parasite Genome

DTIC Science & Technology

2004-03-01

EAA21673 1,443 — — Xeroderma pigmentosum G N&I region, helix-hairpin-helix class P.f., P.k., P.b., P.v. PY02286 EAA21722 696 — — Hypothetical protein...ND PY01828 Gene gun 0.1 2,560 640 Pos IM 0.1 Neg Neg ND CSP Gene gun 0.1 2,560 Neg Neg IM 2.7* 2,560 Neg ND a Parasite burden in liver is in...negative; Pos , positive; ND, not done. c Sera tested at a single dilution (1:80). VOL. 72, 2004 DISCOVERY OF PROTECTIVE MALARIA PARASITE ANTIGENS 1599

Protection against murine intestinal amoebiasis induced by oral immunization with the 29 kDa antigen of Entamoeba histolytica and cholera toxin.

PubMed

Carrero, J C; Contreras-Rojas, A; Sánchez-Hernández, B; Petrosyan, P; Bobes, R J; Ortiz-Ortiz, L; Laclette, J P

2010-11-01

Entamoeba histolytica antigens recognized by salivary IgA from infected patients include the 29 kDa antigen (Eh29), an alkyl hydroperoxide reductase. Here, we investigate the potential of recombinant Eh29 and an Eh29-cholera toxin subunit B (CTxB) fusion protein to confer protection against intestinal amoebiasis after oral immunization. The purified Eh29-CTxB fusion retained the critical ability to bind ganglioside GM(1), as determined by ELISA. Oral immunization of C3H/HeJ mice with Eh29 administered in combination with a subclinical dose of whole cholera toxin, but not as an Eh29-CTxB fusion, induced elevated levels of intestinal IgA and serum IgG anti-Eh29 antibodies that inhibited trophozoites adherence to MDCK cell monolayers. The 80% of immunized mice seen to develop IgA and IgG immune responses showed no evidence of infection in tissue sections harvested following intracecal challenge with virulent E. histolytica trophozoites. These results suggest that Eh29 is capable of inducing protective anti-amoebic immune responses in mice following oral immunization and could be used in the development of oral vaccines against amoebiasis. (c) 2010 Elsevier Inc. All rights reserved.

Tuning B cell responses to antigens by cell polarity and membrane trafficking.

PubMed

Del Valle Batalla, Felipe; Lennon-Dumenil, Ana-María; Yuseff, María-Isabel

2018-06-20

The capacity of B lymphocytes to produce specific antibodies, particularly broadly neutralizing antibodies that provide immunity to viral pathogens has positioned them as valuable therapeutic targets for immunomodulation. To become competent as antibody secreting cells, B cells undergo a series of activation steps, which are triggered by the recognition of antigens frequently displayed on the surface of other presenting cells. Such antigens elicit the formation of an immune synapse (IS), where local cytoskeleton rearrangements coupled to mechanical forces and membrane trafficking orchestrate the extraction and processing of antigens in B cells. In this review, we discuss the molecular mechanisms that regulate polarized membrane trafficking and mechanical properties of the immune synapse, as well as the potential extracellular cues from the environment, which may impact the ability of B cells to sense and acquire antigens at the immune synapse. An integrated view of the diverse cellular mechanisms that shape the immune synapse will provide a better understanding on how B cells are efficiently activated. Copyright © 2018 Elsevier Ltd. All rights reserved.

Anergic self-reactive B cells present self antigen and respond normally to CD40-dependent T-cell signals but are defective in antigen-receptor-mediated functions.

PubMed Central

Eris, J M; Basten, A; Brink, R; Doherty, K; Kehry, M R; Hodgkin, P D

1994-01-01

B-cell tolerance to soluble protein self antigens such as hen egg lysozyme (HEL) is mediated by clonal anergy. Anergic B cells fail to mount antibody responses even in the presence of carrier-primed T cells, suggesting an inability to activate or respond to T helper cells. To investigate the nature of this defect, B cells from tolerant HEL/anti-HEL double-transgenic mice were incubated with a membrane preparation from activated T-cell clones expressing the CD40 ligand. These membranes, together with interleukin 4 and 5 deliver the downstream antigen-independent CD40-dependent B-cell-activating signals required for productive T-B collaboration. Anergic B cells responded to this stimulus by proliferating and secreting antibody at levels comparable to or better than control B cells. Furthermore, anergic B cells presented HEL acquired in vivo and could present the unrelated antigen, conalbumin, targeted for processing via surface IgD. In contrast, the low immunoglobulin receptor levels on anergic B cells were associated with reduced de novo presentation of HEL and a failure to upregulate costimulatory ligands for CD28. These defects in immunoglobulin-receptor-mediated functions could be overcome in vivo, suggesting a number of mechanisms for induction of autoantibody responses. Images PMID:7514304

A plant based protective antigen [PA(dIV)] vaccine expressed in chloroplasts demonstrates protective immunity in mice against anthrax.

PubMed

Gorantala, Jyotsna; Grover, Sonam; Goel, Divya; Rahi, Amit; Jayadev Magani, Sri Krishna; Chandra, Subhash; Bhatnagar, Rakesh

2011-06-15

The currently available anthrax vaccines are limited by being incompletely characterized, potentially reactogenic and have an expanded dosage schedule. Plant based vaccines offer safe alternative for vaccine production. In the present study, we expressed domain IV of Bacillus anthracis protective antigen gene [PA(dIV)] in planta (by nuclear agrobacterium and chloroplast transformation) and E. coli [rPA(dIV)]. The presence of transgene and the expression of PA(dIV) in planta was confirmed by molecular analysis. Expression levels up to 5.3% of total soluble protein (TSP) were obtained with AT rich (71.8% AT content) PA(dIV) gene in transplastomic plants while 0.8% of TSP was obtained in nuclear transformants. Further, we investigated the protective response of plant and E. coli derived PA(dIV) in mice by intraperitoneal (i.p.) and oral immunizations with or without adjuvant. Antibody titers of >10(4) were induced upon i.p. and oral immunizations with plant derived PA(dIV) and oral immunization with E. coli derived PA(dIV). Intraperitoneal injections with adjuvanted E. coli derived PA(dIV), generated highest antibody titers of >10(5). All the immunized groups demonstrated predominant IgG1 titers over IgG2a indicating a polarized Th2 type response. We also evaluated the mucosal antibody response in orally immunized groups. When fecal extracts were analyzed, low sIgA titer was demonstrated in adjuvanted plant and E. coli derived PA(dIV) groups. Further, PA(dIV) antisera enhanced B. anthracis spore uptake by macrophages in vitro and also demonstrated an anti-germinating effect suggesting a potent role at mucosal surfaces. The antibodies from various groups were efficient in neutralizing the lethal toxin in vitro. When mice were challenged with B. anthracis, mice immunized with adjuvanted plant PA(dIV) imparted 60% and 40% protection while E. coli derived PA(dIV) conferred 100% and 80% protection upon i.p. and oral immunizations. Thus, our study is the first attempt in

Disaccharides Protect Antigens from Drying-Induced Damage in Routinely Processed Tissue Sections

PubMed Central

Boi, Giovanna; Scalia, Carla Rossana; Gendusa, Rossella; Ronchi, Susanna; Cattoretti, Giorgio

2015-01-01

Drying of the tissue section, partial or total, during immunostaining negatively affects both the staining of tissue antigens and the ability to remove previously deposited antibody layers, particularly during sequential rounds of de-staining and re-staining for multiple antigens. The cause is a progressive loss of the protein-associated water up to the removal of the non-freezable water, a step which abolishes the immunoavailability of the epitope. In order to describe and prevent these adverse effects, we tested, among other substances, sugars, which are known to protect unicellular organisms from freezing and dehydration, and stabilize drugs and reagents in solid state form in medical devices. Disaccharides (lactose, sucrose) prevented the air drying-induced antigen masking and protected tissue-bound antigens and antibodies from air drying-induced damage. Complete removal of the bound antibody layers by chemical stripping was permitted if lactose was present during air drying. Lactose, sucrose and other disaccharides prevent air drying artifacts, allow homogeneous, consistent staining and the reuse of formalin-fixed, paraffin-embedded tissue sections for repeated immunostaining rounds by guaranteeing constant staining quality in suboptimal hydration conditions. PMID:26487185

Combination of Two Candidate Subunit Vaccine Antigens Elicits Protective Immunity to Ricin and Anthrax Toxin in Mice

PubMed Central

Vance, David J.; Rong, Yinghui; Brey, Robert N.; Mantis, Nicholas J.

2014-01-01

In an effort to develop combination vaccines for biodefense, we evaluated a ricin subunit antigen, RiVax, given in conjunction with an anthrax protective antigen, DNI. The combination led to high endpoint titer antibody response, neutralizing antibodies, and protective immunity against ricin and anthrax lethal toxin. This is a natural combination vaccine, since both antigens are recombinant subunit proteins that would be given to the same target population. PMID:25475957

Immunization with the recombinant antigen Ss-IR induces protective immunity to infection with Strongyloides stercoralis in mice.

PubMed

Abraham, David; Hess, Jessica A; Mejia, Rojelio; Nolan, Thomas J; Lok, James B; Lustigman, Sara; Nutman, Thomas B

2011-10-19

Human intestinal infections with the nematode Strongyloides stercoralis remain a significant problem worldwide and a vaccine would be a useful addition to the tools available to prevent and control this infection. The goal of this study was to test single antigens for their efficacy in a vaccine against S. stercoralis larvae in mice. Alum was used as the adjuvant in these studies and antigens selected for analysis were either recognized by protective human IgG (Ss-TMY-1, Ss-EAT-6, and Ss-LEC-5) or were known to be highly immunogenic in humans (Ss-NIE-1 and Ss-IR). Only mice immunized with the Ss-IR antigen demonstrated a significant decrease of approximately 80% in the survival of larval parasites in the challenge infection. Antibodies, recovered from mice with protective immunity to S. stercoralis after immunization with Ss-IR, were used to locate the antigen in the larvae. Confocal microscopy revealed that IgG from mice immunized with Ss-IR bound to the surface of the parasites and observations by electron microscopy indicated that IgG bound to granules in the glandular esophagus. Serum collected from mice immunized with Ss-IR passively transferred immunity to naïve mice. These studies demonstrate that Ss-IR, in combination with alum, induces high levels of protective immunity through an antibody dependent mechanism and may therefore be suitable for further development as a vaccine against human strongyloidiasis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Performance evaluation of new automated hepatitis B viral markers in the clinical laboratory: two quantitative hepatitis B surface antigen assays and an HBV core-related antigen assay.

PubMed

Park, Yongjung; Hong, Duck Jin; Shin, Saeam; Cho, Yonggeun; Kim, Hyon-Suk

2012-05-01

We evaluated quantitative hepatitis B surface antigen (qHBsAg) assays and a hepatitis B virus (HBV) core-related antigen (HBcrAg) assay. A total of 529 serum samples from patients with hepatitis B were tested. HBsAg levels were determined by using the Elecsys (Roche Diagnostics, Indianapolis, IN) and Architect (Abbott Laboratories, Abbott Park, IL) qHBsAg assays. HBcrAg was measured by using Lumipulse HBcrAg assay (Fujirebio, Tokyo, Japan). Serum aminotransferases and HBV DNA were respectively quantified by using the Hitachi 7600 analyzer (Hitachi High-Technologies, Tokyo, Japan) and the Cobas AmpliPrep/Cobas TaqMan test (Roche). Precision of the qHBsAg and HBcrAg assays was assessed, and linearity of the qHBsAg assays was verified. All assays showed good precision performance with coefficients of variation between 4.5% and 5.3% except for some levels. Both qHBsAg assays showed linearity from 0.1 to 12,000.0 IU/mL and correlated well (r = 0.9934). HBsAg levels correlated with HBV DNA (r = 0.3373) and with HBcrAg (r = 0.5164), and HBcrAg also correlated with HBV DNA (r = 0.5198; P < .0001). This observation could provide impetus for further research to elucidate the clinical usefulness of the qHBsAg and HBcrAg assays.

Determination of O:4 antigen-antibody affinity level in O:5 antigen positive and negative variants of Salmonella enterica serovar Typhimurium.

PubMed

Nakai, Yuka; Ito, Akihisa; Ogawa, Yohsuke; Aribam, Swarmistha Devi; Elsheimer-Matulova, Marta; Shiraiwa, Kazumasa; Kisaka, Stevens M B; Hikono, Hirokazu; Nishikawa, Sayaka; Akiba, Masato; Kawahara, Kazuyoshi; Shimoji, Yoshihiro; Eguchi, Masahiro

2017-04-01

Salmonella enterica serovar Typhimurium (S. Typhimurium) has two serological variants: one that expresses the O:5 antigen (1,4,5,12:i:1,2) and one that lacks O:5 antigen (1,4,12:i:1,2). For serotyping, S. Typhimurium is agglutinated by diagnostic O:4 antigen serum. This study was carried out to compare the antigen-antibody affinity of O:4 antigen in S. Typhimurium χ3306 O:5-positive and S. Typhimurium χ3306 O:5-negative strains. The affinity of O:4 antigen with O:4 antigen serum was found to be stronger in the O:5-negative strains compared to O:5-positive strains. Next, we investigated the antigen-antibody affinity of O:4 antigen with O:4 antigen serum in field strains of S. Typhimurium, which showed the same tendency in affinity as seen with S. Typhimurium χ3306 O:5-positive and negative strains. This study suggests that the presence or absence of O:5 antigen causes differences in O:4 agglutination reactions with different field strains of S. Typhimurium. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Affinity Maturation of an Anti-V Antigen IgG Expressed In Situ Via Adenovirus Gene Delivery Confers Enhanced Protection Against Yersinia pestis Challenge

PubMed Central

Van Blarcom, Thomas J.; Sofer-Podesta, Carolina; Ang, John; Boyer, Julie L.; Crystal, Ronald G.; Georgiou, George

2013-01-01

Genetic transfer of neutralizing antibodies has been shown to confer strong and persistent protection against bacterial and viral infectious agents. While it is well established that for many exogenous neutralizing antibodies increased antigen affinity correlates with protection, the effect of antigen affinity on antibodies produced in situ following adenoviral gene transfer has not been examined. The mouse IgG2b monoclonal antibody 2C12.4 recognizes the Yersinia pestis Type III secretion apparatus protein LcrV (V antigen) and confers protection in mice when administered as an IgG intraperitoneally or, following genetic immunization with engineered, replication-defective serotype 5 human adenovirus (Ad) 1. 2C12.4 was expressed as a scFv fragment in E. coli and was shown to display a KD=3.5 nM by surface plasmon resonance (SPR) analysis. The 2C12.4 scFv was subjected to random mutagenesis and variants with increased affinity were isolated by flow cytometry using the Anchored Periplasmic Expression (APEx) bacterial display system. After a single round of mutagenesis, variants displaying up to 35-fold lower KD values (H8, KD=100 pM) were isolated. The variable domains of the H8 scFv were used to replace those of the parental 2C12.4 IgG encoded in the Ad vector, AdαV giving rise to AdαV.H8. The two adenoviral vectors resulted in similar titers of anti-V antigen antibodies 3 days post-immunization with 109, 1010 or 1011 particle units. Following intranasal challenge with 363 LD50Y. pestis CO92, 54% of the mice immunized with 1010 pu of AdαV.H8 survived at the 14 day end point compared to only 15% survivors for the group immunized with AdαV expressing the lower affinity 2C12.4 (P<0.04, AdαV versus AdαV.H8). These results indicate that affinity maturation of a neutralizing antibody delivered by genetic transfer may confer increased protection not only for Y. pestis challenge but possibly for other pathogens. PMID:20393511

Comparing Assay Performance of ELISA and Chemiluminescence Immunoassay in Detecting Antibodies to Hepatitis B Surface Antigen

PubMed Central

Sagar, Siddharth; Vishwanath, Shashidhar; Banerjee, Barnini; Eshwara, Vandana Kalwaje; Chawla, Kiran

2016-01-01

Introduction Antibodies to Hepatitis B surface Antigen (Anti-HBs) levels are measured as markers for immune response to vaccination and in decision making for post-exposure prophylaxis against Hepatitis-B. Several immunoassay formats are used to measure Anti-HBs, thus carrying the possibility of variation in measured levels between different assays. This study compares the performance of Chemiluminescence Immunoassay (CLIA) against Enzyme-linked Immunosorbent Assay (ELISA) in measuring Anti-HBs titer by looking into concordance between the two test reports. Aim To compare the agreement between ELISA and CLIA in measurement of Anti–HBs antibody titers. Materials and Methods This prospective comparative study conducted at Kasturba Medical College, Manipal measured consecutive serum samples (69) sent for anti-HBs levels during May-June 2016 using both CLIA (Abbott Architect) and ELISA (Bio-Rad). Anti-HBs values of ≤10mIU/ml was considered as non-protective and >10mIU/ml as protective. The agreement between the tests in classifying the antibody titers as non-protective or protective was computed using Kappa coefficient, and the difference in individual titer values between the tests compared using Bland-Altman plot on SPSS (v.15). Results Out of the 69 samples analysed, 18 samples (26.1%) were of health-care personnel and remaining of patients. Agreement between ELISA and CLIA in identifying the antibody titers as protective and non-protective were 96.5% and 90.9% respectively, resulting in an agreement of 0.84. The coefficient-of-variation of ELISA and CLIA were 74.5% and 113.1%, respectively. Three value based discordant results were noted; two samples deemed protective by ELISA were reported as non-protective by CLIA. One non-protective titer by ELISA was reported as protective by CLIA. Conclusion Analytical agreement is good between the two immunoassays. However there are some discrepancies in quantitative measurement. This may have been due the variation in

Production of a fusion protein consisting of the enterotoxigenic Escherichia coli heat-labile toxin B subunit and a tuberculosis antigen in Arabidopsis thaliana.

PubMed

Rigano, M M; Alvarez, M L; Pinkhasov, J; Jin, Y; Sala, F; Arntzen, C J; Walmsley, A M

2004-02-01

Transgenic plants are potentially safe and inexpensive vehicles to produce and mucosally deliver protective antigens. However, the application of this technology is limited by the poor response of the immune system to non-particulate, subunit vaccines. Co-delivery of therapeutic proteins with carrier proteins could increase the effectiveness of the antigen. This paper reports the ability of transgenic Arabidopsis thaliana plants to produce a fusion protein consisting of the B subunit of the Escherichia coli heat-labile enterotoxin and a 6 kDa tuberculosis antigen, the early secretory antigenic target ESAT-6. Both components of the fusion protein were detected using GM1-ganglioside-dependent enzyme-linked immunosorbant assay. This suggested the fusion protein retained both its native antigenicity and the ability to form pentamers.

Antibodies against In Vivo-Expressed Antigens Are Sufficient To Protect against Lethal Aerosol Infection with Burkholderia mallei and Burkholderia pseudomallei.

PubMed

Zimmerman, Shawn M; Dyke, Jeremy S; Jelesijevic, Tomislav P; Michel, Frank; Lafontaine, Eric R; Hogan, Robert J

2017-08-01

Burkholderia mallei , a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. The organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic Gram-negative bacteria. In the present study, we investigated one of these autotransporters, BatA, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in vivo , elicits production of antibodies during infection, and contributes to pathogenicity in a mouse aerosol challenge model. A mutation in the batA gene of wild-type strain ATCC 23344 was found to be particularly attenuating, as BALB/c mice infected with the equivalent of 80 median lethal doses cleared the organism. This finding prompted us to test the hypothesis that vaccination with the batA mutant strain elicits protective immunity against subsequent infection with wild-type bacteria. We discovered that not only does vaccination provide high levels of protection against lethal aerosol challenge with B. mallei ATCC 23344, it also protects against infection with multiple isolates of the closely related organism and causative agent of melioidosis, Burkholderia pseudomallei Passive-transfer experiments also revealed that the protective immunity afforded by vaccination with the batA mutant strain is predominantly mediated by IgG antibodies binding to antigens expressed exclusively in vivo Collectively, our data demonstrate that BatA is a target for developing medical countermeasures and that vaccination with a mutant lacking expression of the protein provides a platform to gain insights regarding mechanisms of protective immunity against B. mallei and B. pseudomallei , including antigen discovery. Copyright © 2017 American Society for Microbiology.

Antibodies against In Vivo-Expressed Antigens Are Sufficient To Protect against Lethal Aerosol Infection with Burkholderia mallei and Burkholderia pseudomallei

PubMed Central

Zimmerman, Shawn M.; Dyke, Jeremy S.; Jelesijevic, Tomislav P.; Michel, Frank; Lafontaine, Eric R.

2017-01-01

ABSTRACT Burkholderia mallei, a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. The organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic Gram-negative bacteria. In the present study, we investigated one of these autotransporters, BatA, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in vivo, elicits production of antibodies during infection, and contributes to pathogenicity in a mouse aerosol challenge model. A mutation in the batA gene of wild-type strain ATCC 23344 was found to be particularly attenuating, as BALB/c mice infected with the equivalent of 80 median lethal doses cleared the organism. This finding prompted us to test the hypothesis that vaccination with the batA mutant strain elicits protective immunity against subsequent infection with wild-type bacteria. We discovered that not only does vaccination provide high levels of protection against lethal aerosol challenge with B. mallei ATCC 23344, it also protects against infection with multiple isolates of the closely related organism and causative agent of melioidosis, Burkholderia pseudomallei. Passive-transfer experiments also revealed that the protective immunity afforded by vaccination with the batA mutant strain is predominantly mediated by IgG antibodies binding to antigens expressed exclusively in vivo. Collectively, our data demonstrate that BatA is a target for developing medical countermeasures and that vaccination with a mutant lacking expression of the protein provides a platform to gain insights regarding mechanisms of protective immunity against B. mallei and B. pseudomallei, including antigen discovery. PMID:28507073

First evaluation of the serum level of anti-hepatitis B surface antigen after vaccination in Libya.

PubMed

Madour, A; Alkout, A; Vanin, S

2013-12-01

The hepatitis B virus (HBV) vaccination schedule in Libya follows international recommendations (1st dose at birth, 2nd after 1 month and 3rd after 6 months). This research aimed to evaluate the long-term protection of the HBV immunization programme in Tripoli and to determine the best age to administer booster doses. Serum levels of hepatitis B surface antigen were determined in 277 randomly selected children aged 1-12 years. The response to HBV vaccine in 1-3-year-olds was 93.2%, but this declined with age and at 7-9 years after initial vaccination only 53.1% of children had protective titres (> or = 10 mIU/mL). No significant differences between males and females in antibody persistence or response to vaccine were observed. We recommend continuing the HBV vaccination programme and that a booster dose be given to 6-year-old children to ensure maximum protection during the period of school entry and beyond.

Evaluation of Aggregated Ag85B Antigen for Its Biophysical Properties, Immunogenicity, and Vaccination Potential in a Murine Model of Tuberculosis Infection

PubMed Central

Ahmad, Faraz; Zubair, Swaleha; Gupta, Pushpa; Gupta, Umesh Datta; Patel, Rakesh; Owais, Mohammad

2017-01-01

Protein aggregates have been reported to act as a reservoir that can release biologically active, native form of precursor protein. Keeping this fact into consideration, it is tempting to exploit protein aggregate-based antigen delivery system as a functional vaccine to expand desirable immunological response in the host. Herein, we explored the capacity of aggregated Ag85B of Mycobacterium tuberculosis (Mtb) to act as a prophylactic vaccine system that releases the precursor antigen in slow and sustained manner. Being particulate system with exposed hydrophobic residues, aggregated Ag85B is likely to be avidly taken up by both phagocytosis as well as fusion with plasma membrane of antigen presenting cells, leading to its direct delivery to their cytosol. Its unique ability to access cytosol of target cells is further evident from the fact that immunization with aggregated Ag85B led to the induction of Th1-dominant immune response along with upregulated expression of qualitatively superior polyfunctional T cells in the mice. Antibodies generated following immunization with aggregated antigen recognized both native and monomeric Ag85B released from protein aggregate. The implicated immunization strategy offers protection at par to that of established BCG vaccine with desirable central and effector memory responses against subsequent Mtb aerosol challenge. The study highlights the potential of aggregated Ag85B as promising antigen delivery system and paves the way to design better prophylactic regimes against various intracellular pathogens including Mtb. PMID:29230211

Thermostable Cross-Protective Subunit Vaccine against Brucella Species

PubMed Central

Barabé, Nicole D.; Grigat, Michelle L.; Lee, William E.; Poirier, Robert T.; Jager, Scott J.; Berger, Bradley J.

2014-01-01

A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 × 105 CFU), and a single injection of 1 μg of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation. PMID:25320267

Antibody Titer Has Positive Predictive Value for Vaccine Protection against Challenge with Natural Antigenic-Drift Variants of H5N1 High-Pathogenicity Avian Influenza Viruses from Indonesia

PubMed Central

Suarez, David L.; Spackman, Erica; Jadhao, Samadhan; Dauphin, Gwenaelle; Kim-Torchetti, Mia; McGrane, James; Weaver, John; Daniels, Peter; Wong, Frank; Selleck, Paul; Wiyono, Agus; Indriani, Risa; Yupiana, Yuni; Sawitri Siregar, Elly; Prajitno, Teguh; Smith, Derek; Fouchier, Ron

2015-01-01

ABSTRACT Vaccines are used in integrated control strategies to protect poultry against H5N1 high-pathogenicity avian influenza (HPAI). H5N1 HPAI was first reported in Indonesia in 2003, and vaccination was initiated in 2004, but reports of vaccine failures began to emerge in mid-2005. This study investigated the role of Indonesian licensed vaccines, specific vaccine seed strains, and emerging variant field viruses as causes of vaccine failures. Eleven of 14 licensed vaccines contained the manufacturer's listed vaccine seed strains, but 3 vaccines contained a seed strain different from that listed on the label. Vaccines containing A/turkey/Wisconsin/1968 (WI/68), A/chicken/Mexico/28159-232/1994 (Mex/94), and A/turkey/England/N28/1973 seed strains had high serological potency in chickens (geometric mean hemagglutination inhibition [HI] titers, ≥1:169), but vaccines containing strain A/chicken/Guangdong/1/1996 generated by reverse genetics (rg; rgGD/96), A/chicken/Legok/2003 (Legok/03), A/chicken/Vietnam/C57/2004 generated by rg (rgVN/04), or A/chicken/Legok/2003 generated by rg (rgLegok/03) had lower serological potency (geometric mean HI titers, ≤1:95). In challenge studies, chickens immunized with any of the H5 avian influenza vaccines were protected against A/chicken/West Java/SMI-HAMD/2006 (SMI-HAMD/06) and were partially protected against A/chicken/Papua/TA5/2006 (Papua/06) but were not protected against A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Experimental inactivated vaccines made with PWT/06 HPAI virus or rg-generated PWT/06 low-pathogenicity avian influenza (LPAI) virus seed strains protected chickens from lethal challenge, as did a combination of a commercially available live fowl poxvirus vaccine expressing the H5 influenza virus gene and inactivated Legok/03 vaccine. These studies indicate that antigenic variants did emerge in Indonesia following widespread H5 avian influenza vaccine usage, and efficacious inactivated vaccines can be developed using

Combination of two candidate subunit vaccine antigens elicits protective immunity to ricin and anthrax toxin in mice.

PubMed

Vance, David J; Rong, Yinghui; Brey, Robert N; Mantis, Nicholas J

2015-01-09

In an effort to develop combination vaccines for biodefense, we evaluated a ricin subunit antigen, RiVax, given in conjunction with an anthrax protective antigen, DNI. The combination led to high endpoint titer antibody response, neutralizing antibodies, and protective immunity against ricin and anthrax lethal toxin. This is a natural combination vaccine, since both antigens are recombinant subunit proteins that would be given to the same target population. Copyright © 2014 Elsevier Ltd. All rights reserved.

BEST: Improved Prediction of B-Cell Epitopes from Antigen Sequences

PubMed Central

Gao, Jianzhao; Faraggi, Eshel; Zhou, Yaoqi; Ruan, Jishou; Kurgan, Lukasz

2012-01-01

Accurate identification of immunogenic regions in a given antigen chain is a difficult and actively pursued problem. Although accurate predictors for T-cell epitopes are already in place, the prediction of the B-cell epitopes requires further research. We overview the available approaches for the prediction of B-cell epitopes and propose a novel and accurate sequence-based solution. Our BEST (B-cell Epitope prediction using Support vector machine Tool) method predicts epitopes from antigen sequences, in contrast to some method that predict only from short sequence fragments, using a new architecture based on averaging selected scores generated from sliding 20-mers by a Support Vector Machine (SVM). The SVM predictor utilizes a comprehensive and custom designed set of inputs generated by combining information derived from the chain, sequence conservation, similarity to known (training) epitopes, and predicted secondary structure and relative solvent accessibility. Empirical evaluation on benchmark datasets demonstrates that BEST outperforms several modern sequence-based B-cell epitope predictors including ABCPred, method by Chen et al. (2007), BCPred, COBEpro, BayesB, and CBTOPE, when considering the predictions from antigen chains and from the chain fragments. Our method obtains a cross-validated area under the receiver operating characteristic curve (AUC) for the fragment-based prediction at 0.81 and 0.85, depending on the dataset. The AUCs of BEST on the benchmark sets of full antigen chains equal 0.57 and 0.6, which is significantly and slightly better than the next best method we tested. We also present case studies to contrast the propensity profiles generated by BEST and several other methods. PMID:22761950

Suboptimal protection against H5N1 highly pathogenic avian influenza viruses from Vietnam in ducks vaccinated with commercial poultry vaccines.

PubMed

Cha, Ra Mi; Smith, Diane; Shepherd, Eric; Davis, C Todd; Donis, Ruben; Nguyen, Tung; Nguyen, Hoang Dang; Do, Hoa Thi; Inui, Ken; Suarez, David L; Swayne, David E; Pantin-Jackwood, Mary

2013-10-09

Domestic ducks are the second most abundant poultry species in many Asian countries including Vietnam, and play a critical role in the epizootiology of H5N1 highly pathogenic avian influenza (HPAI) [FAO]. In this study, we examined the protective efficacy in ducks of two commercial H5N1 vaccines widely used in Vietnam; Re-1 containing A/goose/Guangdong/1/1996 hemagglutinin (HA) clade 0 antigens, and Re-5 containing A/duck/Anhui/1/2006 HA clade 2.3.4 antigens. Ducks received two doses of either vaccine at 7 and at 14 or 21 days of age followed by challenge at 30 days of age with viruses belonging to the HA clades 1.1, 2.3.4.3, 2.3.2.1.A and 2.3.2.1.B isolated between 2008 and 2011 in Vietnam. Ducks vaccinated with the Re-1 vaccine were protected after infection with the two H5N1 HPAI viruses isolated in 2008 (HA clades 1.1 and 2.3.4.3) showing no mortality and limited virus shedding. The Re-1 and Re-5 vaccines conferred 90-100% protection against mortality after challenge with the 2010 H5N1 HPAI viruses (HA clade 2.3.2.1.A); but vaccinated ducks shed virus for more than 7 days after challenge. Similarly, the Re-1 and Re-5 vaccines only showed partial protection against the 2011 H5N1 HPAI viruses (HA clade 2.3.2.1.A and 2.3.2.1.B), with a high proportion of vaccinated ducks shedding virus for more than 10 days. Furthermore, 50% mortality was observed in ducks vaccinated with Re-1 and challenged with the 2.3.2.1.B virus. The HA proteins of the 2011 challenge viruses had the greatest number of amino acid differences from the two vaccines as compared to the viruses from 2008 and 2009, which correlates with the lesser protection observed with these viruses. These studies demonstrate the suboptimal protection conferred by the Re-1 and Re-5 commercial vaccines in ducks against H5N1 HPAI clade 2.3.2.1 viruses, and underscore the importance of monitoring vaccine efficacy in the control of H5N1 HPAI in ducks. Published by Elsevier Ltd.

In vitro antigen-induced, antigen-specific antibody production in man. Specific and polyclonal components, kinetics, and cellular requirements

PubMed Central

1981-01-01

A highly specific and reproducible antigen-induced, antigen-specific culture and assay system for antibody production by human peripheral blood B lymphocytes has been developed. The system is clearly T cell and monocyte dependent and is independent of exogenous mitogens. The major factors in our ability to trigger specific antibody production with antigen alone have been the use of extremely low concentrations of antigen in vitro (doses several orders of magnitude below those inducing a peak blastogenic response), careful attention to in vitro cell density and culture vessel geometry, and appreciation of the kinetics of the circulating antigen-inducible B cell repertoire. A dichotomy and overlap between antigen-induced, antigen-specific and antigen-induced, polyclonal responses was observed in the study of doubly immunized individuals. Whereas antibody responses highly specific for the antigen in culture were observed under one set of culture conditions (flat-bottomed vessels, 1.5 x 10(6) cells), switching to another culture system (round-bottomed vessels, 5 x 10(5) cells) resulted in polyclonal responses to antigen. Despite these culture condition-related differences in the induction of antibody synthesis, the suppression of specific antibody production that occurred at high concentrations of antigen was specific only for the antigen in culture. The capability to easily and reproducibly look at truly antigen-induced, antigen specific antibody production should be a major tool in furthering the understanding of human B cell activation and immunoregulation. PMID:6169778

Controlled Release of Antigens for One Dose Immunization

DTIC Science & Technology

1983-01-01

microencapsulation of antigen coated alum or by microencapsulating clusters of smaller (᝺ microns) microcapsules . Microcapsules under 10 microns in... microencapsulation were studied to determine what criteria must be satisfied to provide a protective immune response to hepatitis B surface antigen... microencapsulated in poly (DL-lactide-co- glycolide) in a form that was too large to be phagocytized and had an antigen release profile similar to that achieved with

B cell activation. III. B cell plasma membrane depolarization and hyper- Ia antigen expression induced by receptor immunoglobulin cross-linking are coupled

PubMed Central

1983-01-01

We report investigation of the relationship between ligand-induced B cell plasma membrane depolarization and increased expression of membrane-associated, I-A subregion encoded (mI-A) antigens. Results demonstrate that equal frequencies of B cells are stimulated to undergo membrane depolarization and to increase mI-A expression in response to mitogen, anti-Ig, and thymus-independent (TI) or thymus-dependent (TD) antigens. Further, a cause-and-effect relationship between these two events is suggested by results that demonstrate that inhibition of anti- Fab--induced depolarization by valinomycin also inhibits the subsequent increase in mI-A antigen expression and "passive" (non-ligand-mediated) depolarization of murine B cells by K+ results in hyper-mI-A antigen expression. Based upon these results we hypothesize that antigen- mediated receptor cross-linking results in signal transduction via membrane depolarization, which is resultant in increased mI-A antigen synthesis and cell surface expression. This increase in mI-A antigen density may render the B cell more receptive to subsequent interaction with I-region-restricted helper T cells. PMID:6415207

Application of recombinant antigen 5 allergens from seven allergy-relevant Hymenoptera species in diagnostics.

PubMed

Schiener, M; Eberlein, B; Moreno-Aguilar, C; Pietsch, G; Serrano, P; McIntyre, M; Schwarze, L; Russkamp, D; Biedermann, T; Spillner, E; Darsow, U; Ollert, M; Schmidt-Weber, C B; Blank, S

2017-01-01

Hymenoptera stings can cause severe anaphylaxis in untreated venom-allergic patients. A correct diagnosis regarding the relevant species for immunotherapy is often hampered by clinically irrelevant cross-reactivity. In vespid venom allergy, cross-reactivity between venoms of different species can be a diagnostic challenge. To address immunological IgE cross-reactivity on molecular level, seven recombinant antigens 5 of the most important Vespoidea groups were assessed by different diagnostic setups. The antigens 5 of yellow jackets, hornets, European and American paper wasps, fire ants, white-faced hornets, and Polybia wasps were recombinantly produced in insect cells, immunologically and structurally characterized, and their sIgE reactivity assessed by ImmunoCAP, ELISA, cross-inhibition, and basophil activation test (BAT) in patients with yellow jacket or Polistes venom allergy of two European geographical areas. All recombinant allergens were correctly folded and structural models and patient reactivity profiles suggested the presence of conserved and unique B-cell epitopes. All antigens 5 showed extensive cross-reactivity in sIgE analyses, inhibition assays, and BAT. This cross-reactivity was more pronounced in ImmunoCAP measurements with venom extracts than in sIgE analyses with recombinant antigens 5. Dose-response curves with the allergens in BAT allowed a differentiated individual dissection of relevant sensitization. Due to extensive cross-reactivity in various diagnostic settings, antigens 5 are inappropriate markers for differential sIgE diagnostics in vespid venom allergy. However, the newly available antigens 5 from further vespid species and the combination of recombinant allergen-based sIgE measurements with BAT represents a practicable way to diagnose clinically relevant sensitization in vespid venom allergy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Generation and characterization of high affinity humanized fab against hepatitis B surface antigen.

PubMed

Tiwari, Ashutosh; Dutta, Durgashree; Khanna, Navin; Acharya, Subrat K; Sinha, Subrata

2009-09-01

5S is a mouse monoclonal IgG1 that binds to the 'a' epitope of the Hepatitis B surface antigen (HBsAg) and tested positive in an in vitro test for virus neutralization. We have earlier reported the generation of humanized single chain variable fragment (scFv) from the same. In this article we report the generation of a recombinant Fab molecule by fusing humanized variable domains of 5S with the constant domains of human IgG1. The humanized Fab expressed in E. coli and subsequently purified, retained a high binding affinity (K(D) = 3.63 nmol/L) to HBsAg and bound to the same epitope of HBsAg as the parent molecule. The humanized Fab also maintained antigen binding in the presence of various destabilizing agents like 3 M NaCl, 30% DMSO, 8 M urea, and extreme pH. This high affinity humanized Fab provides a basis for the development of therapeutic molecules that can be safely utilized for the prophylaxis and treatment for Hepatitis B infection.

Smallpox subunit vaccine produced in planta confers protection in mice

PubMed Central

Golovkin, Maxim; Spitsin, Sergei; Andrianov, Vyacheslav; Smirnov, Yuriy; Xiao, Yuhong; Pogrebnyak, Natalia; Markley, Karen; Brodzik, Robert; Gleba, Yuri; Isaacs, Stuart N.; Koprowski, Hilary

2007-01-01

We report here the in planta production of the recombinant vaccinia virus B5 antigenic domain (pB5), an attractive component of a subunit vaccine against smallpox. The antigenic domain was expressed by using efficient transient and constitutive plant expression systems and tested by various immunization routes in two animal models. Whereas oral administration in mice or the minipig with collard-derived insoluble pB5 did not generate an anti-B5 immune response, intranasal administration of soluble pB5 led to a rise of B5-specific immunoglobulins, and parenteral immunization led to a strong anti-B5 immune response in both mice and the minipig. Mice immunized i.m. with pB5 generated an antibody response that reduced virus spread in vitro and conferred protection from challenge with a lethal dose of vaccinia virus. These results indicate the feasibility of producing safe and inexpensive subunit vaccines by using plant production systems. PMID:17428917

The biological and practical significance of antigenic variability in protective T cell responses against Theileria parva.

PubMed

Morrison, W I

2007-08-19

The evolution of antigenically distinct pathogen strains that fail to cross-protect is well documented for pathogens controlled primarily by humoral immune responses. Unlike antibodies, which recognise native proteins, protective T cells can potentially recognise epitopes in a variety of proteins that are not necessarily displayed on the pathogen surface. Moreover, individual hosts of different MHC genotypes generally respond to different sets of epitopes. It is therefore less easy to envisage how strain restricted immunity can arise for pathogens controlled by T cell responses, particularly in antigenically complex parasites. Nevertheless, strain restricted immunity is clearly a feature of a number of parasitic infections, where immunity is known to be mediated by T cell responses. One such parasite is Theileria parva which induces potent CD8 T cell responses that play an important role in immunity. CD8 T cells specific for parasitized lymphoblasts exhibit strain specificity, which appears to correlate with the ability of parasite strains to cross-protect. Studies using recently identified T. parva antigens recognised by CD8 T cells have shown that the strain restricted nature of immunity is a consequence of the CD8 T cell response in individual animals being focused on a limited number of dominant polymorphic antigenic determinants. Responses in animals of different MHC genotypes are often directed to different parasite antigens, indicating that, at the host population level, a larger number of parasite proteins can serve as targets for the protective T cell response. Nevertheless, the finding that parasite strains show overlapping antigenic profiles, probably as a consequence of sexual recombination, suggests that induction of responses to an extended but limited set of antigens in individual animals may overcome the strain restricted nature of immunity.

Enzyme-linked immunosorbent assay using a recombinant baculovirus-expressed Bacillus anthracis protective antigen (PA): measurement of human anti-PA antibodies.

PubMed Central

Iacono-Connors, L C; Novak, J; Rossi, C; Mangiafico, J; Ksiazek, T

1994-01-01

We developed an antigen capture enzyme-linked immunosorbent assay (ELISA) which does not require purified protective antigen (PA) for detection of human antibodies to Bacillus anthracis PA. Lysates of Spodoptera frugiperda (Sf-9) cells infected with recombinant baculovirus containing the PA gene were used as the source of PA to develop the ELISA. Recombinant PA from crude Sf-9 cell lysates or PA purified from B. anthracis Sterne strain was captured by an anti-PA monoclonal antibody coated onto microtiter plates. We demonstrated that human serum antibody titers to PA were identical in the ELISA whether we used crude Sf-9 cell lysates containing recombinant baculovirus-expressed PA or purified Sterne PA. Finally, false-positive results observed in a direct ELISA were eliminated with this antigen capture ELISA. Thus, the antigen capture ELISA with crude preparations of baculovirus-expressed PA is reliable, safe, and inexpensive for determining anti-PA antibody levels in human sera. PMID:7496927

Multivalent Chromosomal Expression of the Clostridium botulinum Serotype A Neurotoxin Heavy-Chain Antigen and the Bacillus anthracis Protective Antigen in Lactobacillus acidophilus.

PubMed

O'Flaherty, Sarah; Klaenhammer, Todd R

2016-10-15

Clostridium botulinum and Bacillus anthracis produce potent toxins that cause severe disease in humans. New and improved vaccines are needed for both of these pathogens. For mucosal vaccine delivery using lactic acid bacteria, chromosomal expression of antigens is preferred over plasmid-based expression systems, as chromosomal expression circumvents plasmid instability and the need for antibiotic pressure. In this study, we constructed three strains of Lactobacillus acidophilus NCFM expressing from the chromosome (i) the nontoxic host receptor-binding domain of the heavy chain of Clostridium botulinum serotype A neurotoxin (BoNT/A-Hc), (ii) the anthrax protective antigen (PA), and (iii) both the BoNT/A-Hc and the PA. The BoNT/A-Hc vaccine cassette was engineered to contain the signal peptide from the S-layer protein A from L. acidophilus and a dendritic-cell-targeting peptide. A chromosomal region downstream of lba0889 carrying a highly expressed enolase gene was selected for insertion of the vaccine cassettes. Western blot analysis confirmed the heterologous expression of the two antigens from plasmid and chromosome locations. Stability assays demonstrated loss of the vaccine cassettes from expression plasmids without antibiotic maintenance. RNA sequencing showed high expression of each antigen and that insertion of the vaccine cassettes had little to no effect on the transcription of other genes in the chromosome. This study demonstrated that chromosomal integrative recombinant strains are promising vaccine delivery vehicles when targeted into high-expression chromosomal regions. Levels of expression match high-copy-number plasmids and eliminate the requirement for antibiotic selective maintenance of recombinant plasmids. Clostridium botulinum and Bacillus anthracis produce potent neurotoxins that pose a biochemical warfare concern; therefore, effective vaccines against these bacteria are required. Chromosomal expression of antigens is preferred over plasmid

Multivalent Chromosomal Expression of the Clostridium botulinum Serotype A Neurotoxin Heavy-Chain Antigen and the Bacillus anthracis Protective Antigen in Lactobacillus acidophilus

PubMed Central

Klaenhammer, Todd R.

2016-01-01

ABSTRACT Clostridium botulinum and Bacillus anthracis produce potent toxins that cause severe disease in humans. New and improved vaccines are needed for both of these pathogens. For mucosal vaccine delivery using lactic acid bacteria, chromosomal expression of antigens is preferred over plasmid-based expression systems, as chromosomal expression circumvents plasmid instability and the need for antibiotic pressure. In this study, we constructed three strains of Lactobacillus acidophilus NCFM expressing from the chromosome (i) the nontoxic host receptor-binding domain of the heavy chain of Clostridium botulinum serotype A neurotoxin (BoNT/A-Hc), (ii) the anthrax protective antigen (PA), and (iii) both the BoNT/A-Hc and the PA. The BoNT/A-Hc vaccine cassette was engineered to contain the signal peptide from the S-layer protein A from L. acidophilus and a dendritic-cell-targeting peptide. A chromosomal region downstream of lba0889 carrying a highly expressed enolase gene was selected for insertion of the vaccine cassettes. Western blot analysis confirmed the heterologous expression of the two antigens from plasmid and chromosome locations. Stability assays demonstrated loss of the vaccine cassettes from expression plasmids without antibiotic maintenance. RNA sequencing showed high expression of each antigen and that insertion of the vaccine cassettes had little to no effect on the transcription of other genes in the chromosome. This study demonstrated that chromosomal integrative recombinant strains are promising vaccine delivery vehicles when targeted into high-expression chromosomal regions. Levels of expression match high-copy-number plasmids and eliminate the requirement for antibiotic selective maintenance of recombinant plasmids. IMPORTANCE Clostridium botulinum and Bacillus anthracis produce potent neurotoxins that pose a biochemical warfare concern; therefore, effective vaccines against these bacteria are required. Chromosomal expression of antigens is

Induction of the c-myc protooncogene following antigen binding to hapten-specific B cells

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

Snow, E.C.; Fetherston, J.; Zimmer, S.

1986-03-01

Considerable controversy has centered on the role that the surface immunoglobulin (sIg) receptor for antigen plays during the induction of B cell activation. Stimulation by anti-Ig reagents has been shown to activate G/sub 0/ B cells to enter the cell cycle. The binding of thymus-dependent antigens to hapten-specific B cell populations apparently does not result in the movement of the antigen-binding cells (ABC) into the G/sub 1/ stage of the cell cycle. However, the authors have recently demonstrated that antigen binding to such hapten-specific B cells does result in the initiation of the membrane phosphatidylinositol cycle. In the present experiments,more » hapten-specific B cells (80-90% ABC, 99% in G/sub 0/) were incubated with either the correct hapten-carrier conjugate, with the carrier protein, or only media for 2 hours at 37/sup 0/C. At that time, total cellular RNA was isolated and subsequently analyzed by either dot blots or Northern gel techniques. The blots were probed with a (/sup 32/P)-c-myc SstI-Xhol fragment. The results indicate that hapten carrier stimulation of the hapten-specific B cells induces enhanced transcription of the c-myc gene. These observations lend further support to the premise that antigen binding to the sIg receptor results in the transduction to the cell of important signals and implicates the active participation of sIg during the process of antigen-mediated B cell activation.« less

The Fas/CD95 Receptor Regulates the Death of Autoreactive B Cells and the Selection of Antigen-Specific B Cells

PubMed Central

Koncz, Gabor; Hueber, Anne-Odile

2012-01-01

Cell death receptors have crucial roles in the regulation of immune responses. Here we review recent in vivo data confirming that the Fas death receptor (TNFSR6) on B cells is important for the regulation of autoimmunity since the impairment of only Fas function on B cells results in uncontrolled autoantibody production and autoimmunity. Fas plays a role in the elimination of the non-specific and autoreactive B cells in germinal center, while during the selection of antigen-specific B cells different escape signals ensure the resistance to Fas-mediated apoptosis. Antigen-specific survival such as BCR or MHCII signal or coreceptors (CD19) cooperating with BCR inhibits the formation of death inducing signaling complex. Antigen-specific survival can be reinforced by antigen-independent signals of IL-4 or CD40 overproducing the anti-apoptotic members of the Bcl-2 family proteins. PMID:22848207

Oral immunisation with live aroA attenuated Salmonella enterica serovar Typhimurium expressing the Yersinia pestis V antigen protects mice against plague.

PubMed

Garmory, Helen S; Griffin, Kate F; Brown, Katherine A; Titball, Richard W

2003-06-20

Bubonic and pneumonic plague are caused by the bacterium Yersinia pestis. The V antigen of Y. pestis is a protective antigen against plague. In this study, an aroA attenuated strain of Salmonella enterica serovar Typhimurium (SL3261) has been used to deliver the Y. pestis V antigen as a candidate oral plague vaccine. SL3261 was transformed with the expression plasmid pTrc-LcrV, containing the lcrV gene encoding V antigen. Immunoblot analysis showed V antigen expression in SL3261 in vitro and intragastric immunisation of mice with the recombinant Salmonella resulted in the induction of V antigen-specific serum antibody responses and afforded protection against Y. pestis challenge. However, the antibody responses induced by the recombinant Salmonella did not correlate with the protection afforded, indicating that immune responses other than antibody may play a role in the protection afforded against plague by this candidate vaccine.

Fully-human Heavy-chain-only Anti-B-cell Maturation Antigen (BCMA) Chimeric Antigen Receptors (CARs) | NCI Technology Transfer Center | TTC

Cancer.gov

Chimeric Antigen Receptor T cell (CAR-T) therapies that specifically target B-cell maturation antigen (BCMA) are strong therapeutic candidates for patients with plasma cell malignancy diseases such as, multiple myeloma (MM), as well as for patients with Hodgkin’s lymphoma. BCMA is a cell surface protein preferentially expressed on a subset of B cells and mature plasma cells, but not on other cells in the body. The limited expression of BCMA on B and plasma cells makes BCMA an attractive therapeutic target for B cell and plasma cell malignancy diseases. The 12 anti-BCMA CARs described are fully human CARS and have the potential to treat patients with various plasma cell and B cell malignancy diseases.

Protection against anthrax and plague by a combined vaccine in mice and rabbits.

PubMed

Ren, Jun; Dong, Dayong; Zhang, Jinlong; Zhang, Jun; Liu, Shuling; Li, Bing; Fu, Ling; Xu, Junjie; Yu, Changming; Hou, Lihua; Li, Jianmin; Chen, Wei

2009-12-09

The protective antigen (PA) of Bacillus anthracis and the Fraction 1 Capsular Antigen (F1 antigen), V antigen of Yersinia pestis have been demonstrated to be potential immunogens and candidate vaccine sub-units against anthrax and plague respectively. In this study, the authors have investigated the antibody responses and the protective efficacy when the antigens were administered separately or in combination intramuscularly formulation adsorbed to an aluminum hydroxide adjuvant. Results show that immunized rF1 + rV and rPA antigen together was as effective as separately for induction of serological antibody response, and these titers were maintained for over 1 year in mice. An isotype analysis of the serum indicates that the co-administration of these antigens did not influence the antigen-specific IgG1/IgG2a ratio which was consistent with a Th2 bias. Furthermore, the combined vaccine comprising the protein antigens rF1 + rV + rPA has been demonstrated to protect mice from subcutaneous challenge with 10(7) colony-forming units (CFU) virulent Y. pestis strain, and to fully protect rabbit against subcutaneous challenge with 1.2x10(5) colony-forming units (CFU) virulent B. anthracis spores. These data show that the protective efficacy was unaffected when the antigens were administered in combination.

New Method To Generate Enzymatically Deficient Clostridium difficile Toxin B as an Antigen for Immunization

PubMed Central

Genth, Harald; Selzer, Jörg; Busch, Christian; Dumbach, Jürgen; Hofmann, Fred; Aktories, Klaus; Just, Ingo

2000-01-01

The family of the large clostridial cytotoxins, encompassing Clostridium difficile toxins A and B as well as the lethal and hemorrhagic toxins from Clostridium sordellii, monoglucosylate the Rho GTPases by transferring a glucose moiety from the cosubstrate UDP-glucose. Here we present a new detoxification procedure to block the enzyme activity by treatment with the reactive UDP-2′,3′-dialdehyde to result in alkylation of toxin A and B. Alkylation is likely to occur in the catalytic domain, because the native cosubstrate UDP-glucose completely protected the toxins from inactivation and the alkylated toxin competes with the native toxin at the cell receptor. Alkylated toxins are good antigens resulting in antibodies recognizing only the C-terminally located receptor binding domain, whereas formaldehyde treatment resulted in antibodies recognizing both the receptor binding domain and the catalytic domain, indicating that the catalytic domain is concealed under native conditions. Antibodies against the native catalytic domain (amino acids 1 through 546) and those holotoxin antibodies recognizing the catalytic domain inhibited enzyme activity. However, only antibodies against the receptor binding domain protected intact cells from the cytotoxic activity of toxin B, whereas antibodies against the catalytic domain were protective only when inside the cell. PMID:10678912

Schistosome egg antigens, including the glycoprotein IPSE/alpha-1, trigger the development of regulatory B cells

PubMed Central

Veninga, Henrike; van der Vlugt, Luciën E. P. M.; Voskamp, Astrid; Boon, Louis; Westerhof, Lotte B.; Smits, Hermelijn H.

2017-01-01

Infection with the helminth Schistosoma (S.) mansoni drives the development of interleukin (IL)-10-producing regulatory B (Breg) cells in mice and man, which have the capacity to reduce experimental allergic airway inflammation and are thus of high therapeutic interest. However, both the involved antigen and cellular mechanisms that drive Breg cell development remain to be elucidated. Therefore, we investigated whether S. mansoni soluble egg antigens (SEA) directly interact with B cells to enhance their regulatory potential, or act indirectly on B cells via SEA-modulated macrophage subsets. Intraperitoneal injections of S. mansoni eggs or SEA significantly upregulated IL-10 and CD86 expression by marginal zone B cells. Both B cells as well as macrophages of the splenic marginal zone efficiently bound SEA in vivo, but macrophages were dispensable for Breg cell induction as shown by macrophage depletion with clodronate liposomes. SEA was internalized into acidic cell compartments of B cells and induced a 3-fold increase of IL-10, which was dependent on endosomal acidification and was further enhanced by CD40 ligation. IPSE/alpha-1, one of the major antigens in SEA, was also capable of inducing IL-10 in naïve B cells, which was reproduced by tobacco plant-derived recombinant IPSE. Other major schistosomal antigens, omega-1 and kappa-5, had no effect. SEA depleted of IPSE/alpha-1 was still able to induce Breg cells indicating that SEA contains more Breg cell-inducing components. Importantly, SEA- and IPSE-induced Breg cells triggered regulatory T cell development in vitro. SEA and recombinant IPSE/alpha-1 also induced IL-10 production in human CD1d+ B cells. In conclusion, the mechanism of S. mansoni-induced Breg cell development involves a direct targeting of B cells by SEA components such as the secretory glycoprotein IPSE/alpha-1. PMID:28753651

[Comparative study of the antigens of Streptococcus group A. Rport I. Comparative characteristics of the immunologic activity of partially purified M-protien and the cytoplasmic protective antigen].

PubMed

Evseev, V A; Avdeeva, Zh I; Kondrashov, G I

1975-12-01

Experiments were conducted on mice. A study was made of the protective properties of the cytoplasmic fraction of streptococcus, group A, Type 1 and of an antigen isolated from it by sedimentation with ammonium sulfate, in comparison with M-protein partially purified by the method of Lancefield and Perlman. Cytoplasmic antigen was not inferior by immunogenicity in comparison with M-protein. In difference from the latter, it was thermolabile and sensitive to the action of hydrochloric acid. The protective antigen was revealed in the cytoplasm not only of the virulent, but also of avirulent strains of streptococcus devoid of M-protein.

Inactivation of the alpha C protein antigen gene, bca, by a novel shuttle/suicide vector results in attenuation of virulence and immunity in group B Streptococcus.

PubMed

Li, J; Kasper, D L; Ausubel, F M; Rosner, B; Michel, J L

1997-11-25

The alpha C protein of group B Streptococcus (GBS) is a major surface-associated antigen. Although its role in the biology and virulence of GBS has not been defined, it is opsonic and capable of eliciting protective immunity. The alpha C protein is widely distributed among clinical isolates and is a potential protein carrier and antigen in conjugate vaccines to prevent GBS infections. The structural gene for the alpha C protein, bca, has been cloned and sequenced. The protein encoded by bca is related to a class of surface-associated proteins of gram-positive cocci involved in virulence and immunity. To investigate the potential roles of the alpha C protein, bca null mutants were generated in which the bca gene was replaced with a kanamycin resistance cassette via homologous recombination using a novel shuttle/suicide vector. Studies of lethality in neonatal mice showed that the virulence of the bca null mutants was attenuated 5- to 7-fold when compared with the isogenic wild-type strain A909. Significant differences in mortality occurred in the first 24 h, suggesting that the role of the alpha antigen is important in the initial stages of the infection. In contrast to A909, bca mutants were no longer killed by polymorphonuclear leukocytes in the presence of alpha-specific antibodies in an in vitro opsonophagocytic assay. In contrast to previous studies, alpha antigen expression does not appear to play a role in resistance to opsonophagocytosis in the absence of alpha-specific antibodies. In addition, antibodies to the alpha C protein did not passively protect neonatal mice from lethal challenge with bca mutants, suggesting that these epitopes are uniquely present within the alpha antigen as expressed from the bca gene. Therefore, the alpha C protein is important in the pathogenesis of GBS infection and is a target for protective immunity in the development of GBS vaccines.

Biotin avidin amplified magnetic immunoassay for hepatitis B surface antigen detection using GoldMag nanoparticles

NASA Astrophysics Data System (ADS)

Yu, An; Geng, Tingting; Fu, Qiang; Chen, Chao; Cui, Yali

2007-04-01

Using GoldMag (Fe3O4/Au) nanoparticles as a carrier, a biotin-avidin amplified ELISA was developed to detect hepatitis B surface antigen (HBsAg). A specific antibody was labeled with biotin and then used to detect the antigen with an antibody coated on GoldMag nanoparticles by a sandwich ELISA assay. The results showed that 5 mol of biotin were surface bound per mole of antibody. The biotin-avidin amplified ELISA assay has a higher sensitivity than that of the direct ELISA assay. There is 5-fold difference between HBsAg positive and negative serum even at dilution of 1:10000, and the relative standard deviation of the parallel positive serum at dilution of 1:4000 is 5.98% (n=11).

Peripheral B cells latently infected with Epstein–Barr virus display molecular hallmarks of classical antigen-selected memory B cells

PubMed Central

Souza, Tatyana A.; Stollar, B. David; Sullivan, John L.; Luzuriaga, Katherine; Thorley-Lawson, David A.

2005-01-01

Epstein–Barr virus (EBV) establishes a lifelong persistent infection within peripheral blood B cells with the surface phenotype of memory cells. To date there is no proof that these cells have the genotype of true germinal-center-derived memory B cells. It is critical to understand the relative contribution of viral mimicry versus antigen signaling to the production of these cells because EBV encodes proteins that can affect the surface phenotype of infected cells and provide both T cell help and B cell receptor signals in the absence of cognate antigen. To address these questions we have developed a technique to identify single EBV-infected cells in the peripheral blood and examine their expressed Ig genes. The genes were all isotype-switched and somatically mutated. Furthermore, the mutations do not cause stop codons and display the pattern expected for antigen-selected memory cells based on their frequency, type, and location within the Ig gene. We conclude that latently infected peripheral blood B cells display the molecular hallmarks of classical antigen-selected memory B cells. Therefore, EBV does not disrupt the normal processing of latently infected cells into memory, and deviations from normal B cell biology are not tolerated in the infected cells. This article provides definitive evidence that EBV in the peripheral blood persists in true memory B cells. PMID:16330748

Two Distinct Pathways in Mice Generate Antinuclear Antigen-Reactive B Cell Repertoires

PubMed Central

Faderl, Martin; Klein, Fabian; Wirz, Oliver F.; Heiler, Stefan; Albertí-Servera, Llucia; Engdahl, Corinne; Andersson, Jan; Rolink, Antonius

2018-01-01

The escape of anti-self B cells from tolerance mechanisms like clonal deletion, receptor editing, and anergy results in the production of autoantibodies, which is a hallmark of many autoimmune disorders. In this study, we demonstrate that both germline sequences and somatic mutations contribute to autospecificity of B cell clones. For this issue, we investigated the development of antinuclear autoantibodies (ANAs) and their repertoire in two different mouse models. First, in aging mice that were shown to gain several autoimmune features over time including ANAs. Second, in mice undergoing a chronic graft-versus-host disease (GVHD), thereby developing systemic lupus erythematosus-like symptoms. Detailed repertoire analysis revealed that somatic hypermutations (SHM) were present in all Vh and practically all Vl regions of ANAs generated in these two models. The ANA B cell repertoire in aging mice was restricted, dominated by clonally related Vh1-26/Vk4-74 antibodies. In the collection of GVHD-derived ANAs, the repertoire was less restricted, but the usage of the Vh1-26/Vk4-74 combination was still apparent. Germline conversion showed that the SHM in the 4-74 light chain are deterministic for autoreactivity. Detailed analysis revealed that antinuclear reactivity of these antibodies could be induced by a single amino acid substitution in the CDR1 of the Vk4-74. In both aging B6 and young GVHD mice, conversion of the somatic mutations in the Vh and Vl regions of non Vh1-26/Vk4-74 using antibodies showed that B cells with a germline-encoded V gene could also contribute to the ANA-reactive B cell repertoire. These findings indicate that two distinct pathways generate ANA-producing B cells in both model systems. In one pathway, they are generated by Vh1-26/Vk4-74 expressing B cells in the course of immune responses to an antigen that is neither a nuclear antigen nor any other self-antigen. In the other pathway, ANA-producing B cells are derived from progenitors in the bone

Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B

PubMed Central

Obal, Gonzalo; Ramos, Ana Lía; Silva, Valeria; Lima, Analía; Batthyany, Carlos; Bessio, María Inés; Ferreira, Fernando; Salinas, Gustavo; Ferreira, Ana María

2012-01-01

Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by the larval stage (metacestode) of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share homology with a group of hydrophobic ligand binding proteins (HLBPs) present exclusively in cestode organisms, and consist of different isoforms of 8-kDa proteins encoded by a polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5). In vitro studies have shown that EgAgB apolipoproteins are capable of binding fatty acids. However, the identity of the native lipid components of EgAgB remains unknown. The present work was aimed at characterising the lipid ligands bound to EgAgB in vivo. EgAgB was purified to homogeneity from hydatid cyst fluid and its lipid fraction was extracted using chloroform∶methanol mixtures. This fraction constituted approximately 40–50% of EgAgB total mass. High-performance thin layer chromatography revealed that the native lipid moiety of EgAgB consists of a variety of neutral (mainly triacylglycerides, sterols and sterol esters) and polar (mainly phosphatidylcholine) lipids. Gas-liquid chromatography analysis showed that 16∶0, 18∶0 and 18∶1(n-9) are the most abundant fatty acids in EgAgB. Furthermore, size exclusion chromatography coupled to light scattering demonstrated that EgAgB comprises a population of particles heterogeneous in size, with an average molecular mass of 229 kDa. Our results provide the first direct evidence of the nature of the hydrophobic ligands bound to EgAgB in vivo and indicate that the structure and composition of EgAgB lipoprotein particles are more complex than previously thought, resembling high density plasma lipoproteins. Results are discussed considering what is known on lipid metabolism in cestodes, and taken into account the Echinococcus spp. genomic information regarding both lipid

Hepatitis B surface antigen and polymerized albumin binding activity in sheep serum.

PubMed Central

Franklin, S G; Millman, I; Blumberg, B S

1984-01-01

Sera from sheep and other domestic animals contain a substance that gives a strongly positive test for antibody to hepatitis B virus surface antigen by the accepted radioimmunoassay procedure. We have purified this substance from sheep serum to near homogeneity by ion-exchange, affinity, and molecular exclusion chromatography and have identified it to be an IgM. We present evidence that this sheep IgM is an antibody to polymerized sheep albumin. This antibody may arise due to infection by hepatitis B virus, hepatitis B virus-like viruses, or other pathological agents and may react with hepatitis B virus surface antigen by combining with polymerized albumin bound to the hepatitis B virus receptor for this polymer. Images PMID:6582511

Mucosal priming of newborn mice with S. Typhi Ty21a expressing anthrax protective antigen (PA) followed by parenteral PA-boost induces B and T cell-mediated immunity that protects against infection bypassing maternal antibodies

PubMed Central

Ramirez, Karina; Ditamo, Yanina; Galen, James E.; Baillie, Les W. J.; Pasetti, Marcela F.

2010-01-01

The currently licensed anthrax vaccine has several limitations and its efficacy has been proven only in adults. Effective immunization of newborns and infants requires adequate stimulation of their immune system, which is competent but not fully activated. We explored the use of the licensed live attenuated S. Typhi vaccine strain Ty21a expressing Bacillus anthracis protective antigen [Ty21a(PA)] followed PA-alum as a strategy for immunizing the pediatric population. Newborn mice primed with a single dose of Ty21a(PA) exhibited high frequencies of mucosal IgA-secreting B cells and IFN-γ-secreting T cells during the neonatal period, none of which was detected in newborns immunized with a single dose of PA-alum. Priming with Ty21a(PA) followed by PA-boost resulted in high levels of PA-specific IgG, toxin-neutralizing and opsonophagocytic antibodies and increased frequency of bone marrow IgG plasma cells and memory B cells compared with repeated immunization with PA-alum alone. Robust B and T cell responses developed even in the presence of maternal antibodies. The prime-boost protected against systemic and respiratory infection. Mucosal priming with a safe and effective S. Typhi-based anthrax vaccine followed by PA-boost could serve as a practical and effective prophylactic approach to prevent anthrax early in life. PMID:20619377

45 CFR 5b.3 - Policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 1 2012-10-01 2012-10-01 false Policy. 5b.3 Section 5b.3 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PRIVACY ACT REGULATIONS § 5b.3 Policy. It is the policy of the Department to protect the privacy of individuals to the fullest extent possible...

Pivotal Advance: Peritoneal cavity B-1 B cells have phagocytic and microbicidal capacities and present phagocytosed antigen to CD4+ T cells

PubMed Central

Parra, David; Rieger, Aja M.; Li, Jun; Zhang, Yong-An; Randall, Louise M.; Hunter, Christopher A.; Barreda, Daniel R.; Sunyer, J. Oriol

2012-01-01

Breaking the long-held paradigm that primary B cells are not phagocytic, several studies have demonstrated recently that B cells from fish, amphibians, and reptilians have a significant phagocytic capacity. Whether such capacity has remained conserved in certain mammalian B cell subsets is presently an enigma. Here, we report a previously unrecognized ability of PerC B-1a and B-1b lymphocytes to phagocytose latex beads and bacteria. In contrast, B-2 lymphocytes had an almost negligible ability to internalize these particles. Upon phagocytosis, B-1a and B-1b cells were able to mature their phagosomes into phagolysosomes and displayed the ability to kill internalized bacteria. Importantly, B-1a and B-1b cells effectively present antigen recovered from phagocytosed particles to CD4+ T cells. However, these cells showed a much lower competence to present soluble antigen or antigen from large, noninternalized particles. B-1 B cells presented particulate and soluble antigen to CD4+ T cells more efficiently than macrophages, whereas DCs were the most potent APCs. The novel phagocytic and microbicidal abilities identified in B-1 B lymphocytes strengthen the innate nature that has long been attributed to these cells. In the context of adaptive immunity, we show that these innate immune processes are relevant, as they enable B-1 B cells to present phagocytosable particulate antigen. These capacities position these cells at the crossroads that link innate with adaptive immune processes. In a broader context, these newly identified capacities of B-1 B cells further support the previously recognized functional, developmental, and evolutionary relationships between these cells and macrophages. PMID:22058420

Pivotal advance: peritoneal cavity B-1 B cells have phagocytic and microbicidal capacities and present phagocytosed antigen to CD4+ T cells.

PubMed

Parra, David; Rieger, Aja M; Li, Jun; Zhang, Yong-An; Randall, Louise M; Hunter, Christopher A; Barreda, Daniel R; Sunyer, J Oriol

2012-04-01

Breaking the long-held paradigm that primary B cells are not phagocytic, several studies have demonstrated recently that B cells from fish, amphibians, and reptilians have a significant phagocytic capacity. Whether such capacity has remained conserved in certain mammalian B cell subsets is presently an enigma. Here, we report a previously unrecognized ability of PerC B-1a and B-1b lymphocytes to phagocytose latex beads and bacteria. In contrast, B-2 lymphocytes had an almost negligible ability to internalize these particles. Upon phagocytosis, B-1a and B-1b cells were able to mature their phagosomes into phagolysosomes and displayed the ability to kill internalized bacteria. Importantly, B-1a and B-1b cells effectively present antigen recovered from phagocytosed particles to CD4(+) T cells. However, these cells showed a much lower competence to present soluble antigen or antigen from large, noninternalized particles. B-1 B cells presented particulate and soluble antigen to CD4(+) T cells more efficiently than macrophages, whereas DCs were the most potent APCs. The novel phagocytic and microbicidal abilities identified in B-1 B lymphocytes strengthen the innate nature that has long been attributed to these cells. In the context of adaptive immunity, we show that these innate immune processes are relevant, as they enable B-1 B cells to present phagocytosable particulate antigen. These capacities position these cells at the crossroads that link innate with adaptive immune processes. In a broader context, these newly identified capacities of B-1 B cells further support the previously recognized functional, developmental, and evolutionary relationships between these cells and macrophages.

[Eimeria tenella and Eimeria acervulina: an antigenic stimulation in vitro of cells from immune chickens induced by adoptive transfer of protection against avian coccidiosis].

PubMed

Rhalem, A; Sahibi, H; Kazanji, M; Laurent, F; Berrag, B; Péry, P

1993-01-01

The transfer of 5 x 10(7) or 10(8) spleen cells from E tenella-infected chickens to virgin animals after 12-20-h in vitro stimulation with whole sporozoite homogenates confers significant protection to recipients. The oocyst contents of ceca on d 7 post-infection with 20,000 E tenella oocysts were (1.33 +/- 1.10) x 10(6) in chickens which received 5 x 10(7) immune cells after 20-h in vitro stimulation and (4.64 +/- 2.85) x 10(6) in chickens receiving 5 x 10(7) stimulated cells from normal chickens (85% protection). Adoptive transfer by spleen cells revealed an asymmetric cross-protection between E tenella and E acervulina. Spleen cells from E tenella immune chickens protected only against a subsequent infection with the same parasite, while spleen cells from E acervulina immune chickens protected against infection with E acervulina (78%) but also against infection with E tenella (68% protection). The common antigen permits better stimulation, but common surface sporozoite antigens purified from E tenella sporozoites via anti-E acervulina biliary antibodies are capable of stimulating both types of cells without, however, changing their properties.

IgM and IgD B cell receptors differentially respond to endogenous antigens and control B cell fate

PubMed Central

Noviski, Mark; Mueller, James L; Satterthwaite, Anne; Garrett-Sinha, Lee Ann; Brombacher, Frank

2018-01-01

Naive B cells co-express two BCR isotypes, IgM and IgD, with identical antigen-binding domains but distinct constant regions. IgM but not IgD is downregulated on autoreactive B cells. Because these isotypes are presumed to be redundant, it is unknown how this could impose tolerance. We introduced the Nur77-eGFP reporter of BCR signaling into mice that express each BCR isotype alone. Despite signaling strongly in vitro, IgD is less sensitive than IgM to endogenous antigen in vivo and developmental fate decisions are skewed accordingly. IgD-only Lyn−/− B cells cannot generate autoantibodies and short-lived plasma cells (SLPCs) in vivo, a fate thought to be driven by intense BCR signaling induced by endogenous antigens. Similarly, IgD-only B cells generate normal germinal center, but impaired IgG1+ SLPC responses to T-dependent immunization. We propose a role for IgD in maintaining the quiescence of autoreactive B cells and restricting their differentiation into autoantibody secreting cells. PMID:29521626

Characterisation of Antigen B Protein Species Present in the Hydatid Cyst Fluid of Echinococcus canadensis G7 Genotype

PubMed Central

Folle, Ana Maite; Kitano, Eduardo S.; Lima, Analía; Gil, Magdalena; Cucher, Marcela; Mourglia-Ettlin, Gustavo; Iwai, Leo K.; Rosenzvit, Mara; Batthyány, Carlos

2017-01-01

The larva of cestodes belonging to the Echinococcus granulosus sensu lato (s.l.) complex causes cystic echinococcosis (CE). It is a globally distributed zoonosis with significant economic and public health impact. The most immunogenic and specific Echinococcus-genus antigen for human CE diagnosis is antigen B (AgB), an abundant lipoprotein of the hydatid cyst fluid (HF). The AgB protein moiety (apolipoprotein) is encoded by five genes (AgB1-AgB5), which generate mature 8 kDa proteins (AgB8/1-AgB8/5). These genes seem to be differentially expressed among Echinococcus species. Since AgB immunogenicity lies on its protein moiety, differences in AgB expression within E. granulosus s.l. complex might have diagnostic and epidemiological relevance for discriminating the contribution of distinct species to human CE. Interestingly, AgB2 was proposed as a pseudogene in E. canadensis, which is the second most common cause of human CE, but proteomic studies for verifying it have not been performed yet. Herein, we analysed the protein and lipid composition of AgB obtained from fertile HF of swine origin (E. canadensis G7 genotype). AgB apolipoproteins were identified and quantified using mass spectrometry tools. Results showed that AgB8/1 was the major protein component, representing 71% of total AgB apolipoproteins, followed by AgB8/4 (15.5%), AgB8/3 (13.2%) and AgB8/5 (0.3%). AgB8/2 was not detected. As a methodological control, a parallel analysis detected all AgB apolipoproteins in bovine fertile HF (G1/3/5 genotypes). Overall, E. canadensis AgB comprised mostly AgB8/1 together with a heterogeneous mixture of lipids, and AgB8/2 was not detected despite using high sensitivity proteomic techniques. This endorses genomic data supporting that AgB2 behaves as a pseudogene in G7 genotype. Since recombinant AgB8/2 has been found to be diagnostically valuable for human CE, our findings indicate that its use as antigen in immunoassays could contribute to false negative results in

Characterisation of Antigen B Protein Species Present in the Hydatid Cyst Fluid of Echinococcus canadensis G7 Genotype.

PubMed

Folle, Ana Maite; Kitano, Eduardo S; Lima, Analía; Gil, Magdalena; Cucher, Marcela; Mourglia-Ettlin, Gustavo; Iwai, Leo K; Rosenzvit, Mara; Batthyány, Carlos; Ferreira, Ana María

2017-01-01

The larva of cestodes belonging to the Echinococcus granulosus sensu lato (s.l.) complex causes cystic echinococcosis (CE). It is a globally distributed zoonosis with significant economic and public health impact. The most immunogenic and specific Echinococcus-genus antigen for human CE diagnosis is antigen B (AgB), an abundant lipoprotein of the hydatid cyst fluid (HF). The AgB protein moiety (apolipoprotein) is encoded by five genes (AgB1-AgB5), which generate mature 8 kDa proteins (AgB8/1-AgB8/5). These genes seem to be differentially expressed among Echinococcus species. Since AgB immunogenicity lies on its protein moiety, differences in AgB expression within E. granulosus s.l. complex might have diagnostic and epidemiological relevance for discriminating the contribution of distinct species to human CE. Interestingly, AgB2 was proposed as a pseudogene in E. canadensis, which is the second most common cause of human CE, but proteomic studies for verifying it have not been performed yet. Herein, we analysed the protein and lipid composition of AgB obtained from fertile HF of swine origin (E. canadensis G7 genotype). AgB apolipoproteins were identified and quantified using mass spectrometry tools. Results showed that AgB8/1 was the major protein component, representing 71% of total AgB apolipoproteins, followed by AgB8/4 (15.5%), AgB8/3 (13.2%) and AgB8/5 (0.3%). AgB8/2 was not detected. As a methodological control, a parallel analysis detected all AgB apolipoproteins in bovine fertile HF (G1/3/5 genotypes). Overall, E. canadensis AgB comprised mostly AgB8/1 together with a heterogeneous mixture of lipids, and AgB8/2 was not detected despite using high sensitivity proteomic techniques. This endorses genomic data supporting that AgB2 behaves as a pseudogene in G7 genotype. Since recombinant AgB8/2 has been found to be diagnostically valuable for human CE, our findings indicate that its use as antigen in immunoassays could contribute to false negative results in

Protective effects of murine monoclonal antibodies in experimental septicemia: E. coli antibodies protect against different serotypes of E. coli.

PubMed

Salles, M F; Mandine, E; Zalisz, R; Guenounou, M; Smets, P

1989-04-01

Murine monoclonal antibodies that bind outer membrane antigens of the J5 mutant of Escherichia coli O111:B4 were derived from spleen cells of BALB/c mice immunized with killed whole cells and boosted with lipopolysaccharide (LPS) and LPS-associated proteins. Seven hybridomas were selected for their reactivity against the J5 LPS; they cross-reacted with O111, O55, O127, and O128 E. coli LPS. One (B7B3) also reacted with the Serratia marcescens LPS and Klebsiella pneumoniae lipid A. A protective effect was obtained with D6B4 antibody in a lethal endotoxemia model induced by LPS from O111, O127, and O128 E. coli serotypes in D-galactosamine-sensitized mice. D6B4 and D6B3 antibodies protected mice infected with E. coli O111:B4, when administered before infection. The D6B4 antibody was also protective when administered after infection. The antibodies D6B3 and D4B5 were protective in heterologous infection induced by E. coli O2:K1.

Capsule null locus meningococci: typing of antigens used in an investigational multicomponent meningococcus serogroup B vaccine.

PubMed

Claus, Heike; Jördens, Markus S; Kriz, Pavla; Musilek, Martin; Jarva, Hanna; Pawlik, Marie-Christin; Meri, Seppo; Vogel, Ulrich

2012-01-05

The investigational multicomponent meningococcus serogroup B vaccine (4CMenB) targets the antigenetically variable population of serogroup B meningococci. Forty-one strains of capsule null locus (cnl) meningococci, which are frequent among healthy carriers, were selected from nine sequence types (ST), which belong to four clonal complexes (cc), and three countries. They were antigen sequence typed and analyzed for antigen expression to predict whether these strains harbor the genes and express the four vaccine antigens of 4CMenB as measured by the meningococcal antigen typing system (MATS). The PorA variant used in the vaccine was not found. The nadA gene was absent in all but one strain, which did not express the antigen in vitro. Only strains of clonal complex ST-198 harbored a factor H binding protein (FHBP) allele of the cross-reactive variant 1 family which is included in the vaccine. All these strains expressed the antigen. Five variants of the Neisserial heparin binding antigen (NHBA) gene were identified. Expression of NHBA was observed in all strains with highest levels in ST-198 cc and ST-845. The data suggest a potential impact of 4CMenB immunization at least on cnl meningococci of the ST-198 cc and ST-845. Copyright © 2011 Elsevier Ltd. All rights reserved.

34 CFR 5b.3 - Policy.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 1 2012-07-01 2012-07-01 false Policy. 5b.3 Section 5b.3 Education Office of the Secretary, Department of Education PRIVACY ACT REGULATIONS § 5b.3 Policy. It is the policy of the Department to protect the privacy of individuals to the fullest extent possible while nonetheless permitting the...

Effects of hydroformylation treatment on the storage time and blood group antigen expressions of reagent red blood cells.

PubMed

Yu, Yang; Sun, Xiaolin; Guan, Xiaozhen; Zhang, Xiaojuan; Ma, Chunya; Chen, Linfeng; Wang, Deqing

2014-06-01

To evaluate the effects of hydroformylation treatment on the storage time and blood group antigen expressions of reagent red blood cells (RBCs). RBCs from healthy donors were treated by using various final concentrations of paraformaldehyde (0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%) and glutaraldehyde (0.01%, 0.025%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%), and one aliquot was used as control (untreated with aldehydes). Supernatant free hemoglobin (FHb) levels in all groups stored at 4 °C were detected every week, and the optimal procedure was selected. Expression of blood group antigens on RBCs treated by the optimal procedure was determined, and the total scores of blood group antigens were calculated. 0.2%, 0.5% and 1.0% Glutaraldehyde groups were ruled out directly due to serious crosslinking and aggregation of RBCs. As the extension of time, FHb levels in other 11 groups gradually increased (p<0.01 or p<0.05). FHb level in 0.025% glutaraldehyde group was significantly lower than that in other groups after 13 weeks (p<0.01), and the antigen strength of Fy(b), Jk(b), and Le(b) decreased slightly compared with those before treatment and storage (p<0.05), and there was no significant change for antigen strength of A, B, D, C, E, c, e, M, N, S, s, k, P1, Fy(a), Jk(a), and Le(a) (p>0.05). 0.025% Glutaraldehyde treatment can provide optimal protection for the membrane of RBCs and keep hemolysis at a low level after 13 weeks storage, and the majority of blood group antigen systems are not significantly affected, and the slight decline of Fy(b), Jk(b), and Le(b) antigen strength was acceptable for classical serological tests. Copyright © 2014 Elsevier Ltd. All rights reserved.

Immunogenicity of transgenic plant-derived hepatitis B surface antigen.

PubMed Central

Thanavala, Y; Yang, Y F; Lyons, P; Mason, H S; Arntzen, C

1995-01-01

The focus of the Children's Vaccine Initiative is to encourage the discovery of technology that will make vaccines more readily available to developing countries. Our strategy has been to genetically engineer plants so that they can be used as inexpensive alternatives to fermentation systems for production of subunit antigens. In this paper we report on the immunological response elicited in vivo by using recombinant hepatitis B surface antigen (rHBsAg) purified from transgenic tobacco leaves. The anti-hepatitis B response to the tobacco-derived rHBsAg was qualitatively similar to that obtained by immunizing mice with yeast-derived rHBsAg (commercial vaccine). Additionally, T cells obtained from mice primed with the tobacco-derived rHBsAg could be stimulated in vitro by the tobacco-derived rHBsAg, yeast-derived rHBsAg, and by a synthetic peptide that represents part of the a determinant located in the S region (139-147) of HBsAg. Further support for the integrity of the T-cell epitope of the tobacco-derived rHBsAg was obtained by testing the ability of the primed T cells to proliferate in vitro after stimulation with a monoclonal anti-idiotype and an anti-idiotype-derived peptide, both of which mimic the group-specific a determinant of HBsAg. In total, we have conclusively demonstrated that both B- and T-cell epitopes of HBsAg are preserved when the antigen is expressed in a transgenic plant. PMID:7724566

Parasite genetics and the immune host: recombination between antigenic types of Eimeria maxima as an entrée to the identification of protective antigens.

PubMed

Blake, Damer P; Hesketh, Patricia; Archer, Andrew; Carroll, Fionnadh; Smith, Adrian L; Shirley, Martin W

2004-11-01

The genomes of protozoan parasites encode thousands of gene products and identification of the subset that stimulates a protective immune response is a daunting task. Most screens for vaccine candidates identify molecules by capacity to induce immune responses rather than protection. This paper describes the core findings of a strategy developed with the coccidial parasite Eimeria maxima to rationally identify loci within its genome that encode immunoprotective antigens. Our strategy uses a novel combination of parasite genetics, DNA fingerprinting, drug-resistance and strain-specific immunity and centres on two strains of E. maxima that each induce a lethal strain-specific protective immune response in the host and show a differential response to anti-Eimeria chemotherapy. Through classical mating studies with these strains we have demonstrated that loci encoding molecules stimulating strain-specific protective immunity or resistance to the anti-coccidial drug robenidine segregate independently. Furthermore, passage of populations of recombinant parasites in the face of killing in the immune host was accompanied by the elimination of some polymorphic DNA markers defining the parent strain used to immunise the host. Consideration of the numbers of parasites recombinant for the two traits implicates very few antigen-encoding loci. Our data provide a potential strategy to identify putative antigen-encoding loci in other parasites.

Preliminary characterization of Thy-1.1 and Ag-B antigens from rat tissues solubilized in detergents

PubMed Central

Letarte-Muirhead, Michelle; Acton, Ronald T.; Williams, Alan F.

1974-01-01

1. A radioactive binding assay for Thy-1.1 alloantigen which functions in the presence of detergents was established by using glutaraldehyde-fixed thymocytes as target cells. Thy-1.1 activity in detergent extracts was then assayed by measuring inhibition of the binding assay. 2. Solubilization of Thy-1.1 from whole thymocytes, and their membranes by a large number of non-ionic detergents and deoxycholate was studied. In the same extracts Ag-B(4) histocompatibility antigenic activities were measured. With the exception of Nonidet P-40, the detergents did not affect the antigenicity of Thy-1.1, but only Lubrol-PX and deoxycholate gave effective solubilization as measured by activity remaining in the supernatant after centrifugation at 200000g for 40min. With Ag-B(4) antigen, Triton X-100, Triton X-67 and Nonidet P-40 gave effective solubilization as well as Lubrol-PX and deoxycholate. Solubilization of Thy-1.1 activity from leukaemia cells and a brain homogenate was also studied, but none of the non-ionic detergents gave satisfactory results with these tissues. 3. Extracts from thymocyte membranes were further examined by gel filtration and sucrose gradient centrifugation. The Thy-1.1 activity behaved as a single component in deoxycholate with a density similar to that of a globular protein, but in Lubrol-PX the antigen was contained in a low-density complex. In Lubrol-PX extracts Ag-B(4) was also found in aggregates not observed in deoxycholate. 4. The s20,w values for Thy-1.1 and Ag-B(4) antigens in deoxycholate were 2.4 and 4.4, and v̄ values were 0.70 and 0.75 respectively. The Stokes radius observed for Thy-1.1 was 3.1nm and for Ag-B(4) 5.3nm. By using these values the molecular weights for the antigen–detergent complexes were calculated to be 28000 for Thy-1.1 and 100000 for Ag-B(4). PMID:4219284

Efficacy of antigen dosage on the hepatitis B vaccine response in infants born to hepatitis B-uninfected and hepatitis B-infected mothers.

PubMed

Kang, Guodong; Ma, Fubao; Chen, Haiping; Yang, Yunkai; Guo, Shaohong; Wang, Zhiguo; Liang, Xiaofeng; Li, Li; Cui, Fuqiang; Zhang, Longhua

2015-08-07

To compare the safety and immunogenicity of two dosages of recombinant hepatitis B (HB) vaccine administered to infants born to HB-uninfected and HB-infected mothers. A phase III, controlled, single-blinded clinical trial was conducted with 506 healthy newborns. The newborns were assigned to three groups based on maternal levels of HB surface antigen (HBsAg) and HB e antigen (HBeAg): Group A, HBsAg negative; Group B, HBsAg positive and HBeAg negative; and Group C, HBsAg positive and HBeAg positive. Three doses of 10 or 5 μg recombinant HB vaccine were randomly administered by 1:1 within 24 h after birth, at 1 month and at 6 months. Safety data and pre- and postvaccination blood samples were collected. A total of 326, 93, and 87 subjects were included in Groups A, B, and C, respectively. Both dosages of HB vaccine were well tolerated by all subjects. The most common injection-site adverse reactions (ARs) and systemic ARs were pain and fever. After 1 month of the third dose, the Group A infants who received the 10 μg HB vaccine achieved a higher geometric mean concentration (GMC) of HB surface antibody (anti-HBs) than those who received the 5 μg dosage. Maternal anti-HBs serostatus did not influence HB vaccine immunogenicity at either dosage. In contrast, there was no significant difference in the anti-HBs seroconversion rate, GMCs, or estimated vaccine efficacy (EVE) against perinatal transmission between Groups B and C, regardless of dosage. However, the seroconversion rate and EVE of the 5 μg HB vaccine was lower in Group C than in Group B. Both dosages of the HB vaccine were well tolerated and elicited a good immune response in infants of Group A, regardless of the maternal anti-HBs serostatus. EVE did not significantly differ between Groups B and C. Clinicaltrials.gov identifier: NCT02152709. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Replication-Defective Human Type 5 Adenovirus-Based Trivalent Vaccine Confers Complete Protection against Plague in Mice and Nonhuman Primates

PubMed Central

Kirtley, Michelle L.; Klages, Curtis; Erova, Tatiana E.; Telepnev, Maxim; Ponnusamy, Duraisamy; Fitts, Eric C.; Baze, Wallace B.; Sivasubramani, Satheesh K.; Lawrence, William S.; Patrikeev, Igor; Peel, Jennifer E.; Andersson, Jourdan A.; Kozlova, Elena V.; Tiner, Bethany L.; Peterson, Johnny W.; McWilliams, David; Patel, Snehal; Rothe, Eric; Motin, Vladimir L.

2016-01-01

Currently, no plague vaccine exists in the United States for human use. The capsular antigen (Caf1 or F1) and two type 3 secretion system (T3SS) components, the low-calcium-response V antigen (LcrV) and the needle protein YscF, represent protective antigens of Yersinia pestis. We used a replication-defective human type 5 adenovirus (Ad5) vector and constructed recombinant monovalent and trivalent vaccines (rAd5-LcrV and rAd5-YFV) that expressed either the codon-optimized lcrV or the fusion gene designated YFV (consisting of ycsF, caf1, and lcrV). Immunization of mice with the trivalent rAd5-YFV vaccine by either the intramuscular (i.m.) or the intranasal (i.n.) route provided protection superior to that with the monovalent rAd5-LcrV vaccine against bubonic and pneumonic plague when animals were challenged with Y. pestis CO92. Preexisting adenoviral immunity did not diminish the protective response, and the protection was always higher when mice were administered one i.n. dose of the trivalent vaccine (priming) followed by a single i.m. booster dose of the purified YFV antigen. Immunization of cynomolgus macaques with the trivalent rAd5-YFV vaccine by the prime-boost strategy provided 100% protection against a stringent aerosol challenge dose of CO92 to animals that had preexisting adenoviral immunity. The vaccinated and challenged macaques had no signs of disease, and the invading pathogen rapidly cleared with no histopathological lesions. This is the first report showing the efficacy of an adenovirus-vectored trivalent vaccine against pneumonic plague in mouse and nonhuman primate (NHP) models. PMID:27170642

Immunological evaluation of colonic delivered Hepatitis B surface antigen loaded TLR-4 agonist modified solid fat nanoparticles.

PubMed

Sahu, Kantrol Kumar; Pandey, Ravi Shankar

2016-10-01

Hepatitis B is one of the leading liver diseases and remains a major global health problem. Currently available vaccines provide protection but often results in weaker/minimal mucosal immunity. Thus the present study is devoted to the development and in-vivo exploration of the colonically delivered biomimetic nanoparticles which capably enhance humoral as well as cellular immune response. In present work, Hepatitis B surface antigen (HBsAg) entrapped nanoparticles containing Monophosphoryl lipid A (MPLA) (HB+L-NP) were prepared by solvent evaporation method and characterized for particle size (~210nm), shape, zeta potential (-24mV±0.68), entrapment efficiency (58.45±1.68%), in-vitro release and antigen integrity. Dose escalation study was done to confirm prophylactic immune response following defined doses of prepared nanoparticulate formulations with or without MPLA. Intramuscular administered alum based marketed HBsAg (Genevac B) was used as standard (10μg) and were able to induce significant systemic (IgG) but remarkably low mucosal immune (IgA) response. Notably, HB+L-NP (0.5ml-10μg) induced strong systemic and robust mucosal immunity (510 and 470 mIU/ml respectively, p<0.001) from which mucosal was more significant due to the involvement of Common Mucosal Immune System (CMIS). Likewise, significant cellular immune response was elicited by HB+L-NP through T-cell activation (mixed Th1 and Th2) as confirmed by significantly increased cytokines level (IL-2 and Interferon-γ) in spleen homogenates. This study supports that delivery of HBsAg to the colon may open new vista in designing oral vaccines later being one of most accepted route for potential vaccines in future. Copyright © 2016 Elsevier B.V. All rights reserved.

Rabies virus glycoprotein as a carrier for anthrax protective antigen

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

Smith, Mary Ellen; Koser, Martin; Xiao Sa

2006-09-30

Live viral vectors expressing foreign antigens have shown great promise as vaccines against viral diseases. However, safety concerns remain a major problem regarding the use of even highly attenuated viral vectors. Using the rabies virus (RV) envelope protein as a carrier molecule, we show here that inactivated RV particles can be utilized to present Bacillus anthracis protective antigen (PA) domain-4 in the viral membrane. In addition to the RV glycoprotein (G) transmembrane and cytoplasmic domains, a portion of the RV G ectodomain was required to express the chimeric RV G anthrax PA on the cell surface. The novel antigen wasmore » also efficiently incorporated into RV virions. Mice immunized with the inactivated recombinant RV virions exhibited seroconversion against both RV G and anthrax PA, and a second inoculation greatly increased these responses. These data demonstrate that a viral envelope protein can carry a bacterial protein and that a viral carrier can display whole polypeptides compared to the limited epitope presentation of previous viral systems.« less

Variable protection against experimental broiler necrotic enteritis after immunization with the C-terminal fragment of Clostridium perfringens alpha-toxin and a non-toxic NetB variant.

PubMed

Fernandes da Costa, Sérgio P; Mot, Dorien; Geeraerts, Sofie; Bokori-Brown, Monika; Van Immerseel, Filip; Titball, Richard W

2016-06-01

Necrotic enteritis toxin B (NetB) is a pore-forming toxin produced by Clostridium perfringens and has been shown to play a key role in avian necrotic enteritis, a disease causing significant costs to the poultry production industry worldwide. The aim of this work was to determine whether immunization with a non-toxic variant of NetB (NetB W262A) and the C-terminal fragment of C. perfringens alpha-toxin (CPA247-370) would provide protection against experimental necrotic enteritis. Immunized birds with either antigen or a combination of antigens developed serum antibody levels against NetB and CPA. When CPA247-370 and NetB W262A were used in combination as immunogens, an increased protection was observed after oral challenge by individual dosing, but not after in-feed-challenge.

Cytotoxic T lymphocyte recognition of HLA-A/B antigens introduced into EL4 cells by cell-liposome fusion.

PubMed

Engelhard, V H; Powers, G A; Moore, L C; Holterman, M J; Correa-Freire, M C

1984-01-01

HLA-A2 and -B7 antigens were introduced into EL4 (H-2b) cells by cell-liposome fusion and were used as targets or stimulators for cytotoxic T lymphocytes (CTL) generated in C57B1/6 (H-2b) mice. It was found that such EL4-HLA cells were not recognized by CTL that had been raised against either a human cell line bearing these HLA antigens or the purified HLA-A2 and -B7 antigens reconstituted into liposomes. In addition, EL4-HLA cells were not capable of inducing CTL that could recognize a human cell line bearing HLA-A2 and -B7 antigens. Instead, EL4-HLA cells induced CTL that specifically lysed EL4-HLA cells and not human cells expressing HLA-A2 and -B7. CTL recognition required the presence of HLA antigens on the EL4 cell surface and was inhibited by antibodies against either H-2b or HLA-A/B. Monoclonal antibody binding studies showed that the expected polymorphic determinants of the HLA-A2 and -B7 antigens were still present on EL4-HLA cells. However, the specificity of CTL or their precursors that are capable of recognizing HLA-A2 or -B7 was altered after these antigens became associated with the EL4 surface. Possible explanations for these results are discussed.

Effective Targeting of Multiple B-Cell Maturation Antigen-Expressing Hematological Malignances by Anti-B-Cell Maturation Antigen Chimeric Antigen Receptor T Cells.

PubMed

Friedman, Kevin M; Garrett, Tracy E; Evans, John W; Horton, Holly M; Latimer, Howard J; Seidel, Stacie L; Horvath, Christopher J; Morgan, Richard A

2018-05-01

B-cell maturation antigen (BCMA) expression has been proposed as a marker for the identification of malignant plasma cells in patients with multiple myeloma (MM). Nearly all MM tumor cells express BCMA, while normal tissue expression is restricted to plasma cells and a subset of mature B cells. Consistent BCMA expression was confirmed on MM biopsies (29/29 BCMA+), and it was further demonstrated that BCMA is expressed in a substantial number of lymphoma samples, as well as primary chronic lymphocytic leukemia B cells. To target BCMA using redirected autologous T cells, lentiviral vectors (LVV) encoding chimeric antigen receptors (CARs) were constructed with four unique anti-BCMA single-chain variable fragments, fused to the CD137 (4-1BB) co-stimulatory and CD3ζ signaling domains. One LVV, BB2121, was studied in detail, and BB2121 CAR-transduced T cells (bb2121) exhibited a high frequency of CAR + T cells and robust in vitro activity against MM cell lines, lymphoma cell lines, and primary chronic lymphocytic leukemia peripheral blood. Based on receptor quantification, bb2121 recognized tumor cells expressing as little as 222 BCMA molecules per cell. The in vivo pharmacology of anti-BCMA CAR T cells was studied in NSG mouse models of human MM, Burkitt lymphoma, and mantle cell lymphoma, where mice received a single intravenous administration of vehicle, control vector-transduced T cells, or anti-BCMA CAR-transduced T cells. In all models, the vehicle and control CAR T cells failed to inhibit tumor growth. In contrast, treatment with bb2121 resulted in rapid and sustained elimination of the tumors and 100% survival in all treatment models. Together, these data support the further development of anti-BCMA CAR T cells as a potential treatment for not only MM but also some lymphomas.

Generation of protective immune response against anthrax by oral immunization with protective antigen plant-based vaccine.

PubMed

Gorantala, Jyotsna; Grover, Sonam; Rahi, Amit; Chaudhary, Prerna; Rajwanshi, Ravi; Sarin, Neera Bhalla; Bhatnagar, Rakesh

2014-04-20

In concern with frequent recurrence of anthrax in endemic areas and inadvertent use of its spores as biological weapon, the development of an effective anthrax vaccine suitable for both human and veterinary needs is highly desirable. A simple oral delivery through expression in plant system could offer promising alternative to the current methods that rely on injectable vaccines extracted from bacterial sources. In the present study, we have expressed protective antigen (PA) gene in Indian mustard by Agrobacterium-mediated transformation and in tobacco by plastid transformation. Putative transgenic lines were verified for the presence of transgene and its expression by molecular analysis. PA expressed in transgenic lines was biologically active as evidenced by macrophage lysis assay. Intraperitoneal (i.p.) and oral immunization with plant PA in murine model indicated high serum PA specific IgG and IgA antibody titers. PA specific mucosal immune response was noted in orally immunized groups. Further, antibodies indicated lethal toxin neutralizing potential in-vitro and conferred protection against in-vivo toxin challenge. Oral immunization experiments demonstrated generation of immunoprotective response in mice. Thus, our study examines the feasibility of oral PA vaccine expressed in an edible plant system against anthrax. Copyright © 2014 Elsevier B.V. All rights reserved.

Immunity against mouse thymus-leukemia antigen (TL) protects against development of lymphomas induced by a chemical carcinogen, N-butyl-N-nitrosourea.

PubMed

Tsujimura, Kunio; Obata, Yuichi; Matsudaira, Yasue; Ozeki, Satoshi; Taguchi, Osamu; Nishida, Keiko; Okanami, Yuko; Akatsuka, Yoshiki; Kuzushima, Kiyotaka; Takahashi, Toshitada

2004-11-01

Mouse thymus-leukemia antigens (TL) are aberrantly expressed on T lymphomas in C57BL/6 (B6) and C3H/He (C3H) mice, while they are not expressed on normal T lymphocytes in these strains. When N-butyl-N-nitrosourea (NBU), a chemical carcinogen, was administered orally to B6 and C3H strains, lymphoma development was slower than in T3(b)-TL gene-transduced counterpart strains expressing TL ubiquitously as self-antigens, suggesting that anti-TL immunity may play a protective role. In addition, the development of lymphomas was slightly slower in C3H than in B6, which seems to be in accordance with the results of skin graft experiments indicating that both cellular and humoral immunities against TL were stronger in C3H than B6 mice. The interesting finding that B lymphomas derived from a T3(b)-TL transgenic strain (C3H background) expressing a very high level of TL were rejected in C3H, but not in H-2K(b) transgenic mice (C3H background), raises the possibility that TL-specific effector T cell populations are eliminated and/or energized to a certain extent by interacting with H-2K(b) molecules.

Identification and characterization of B cell precursors in rat lymphoid tissues. I. Adoptive transfer assays for precursors of TI-1, TI-2, and TD antigen-reactive B cells.

PubMed

Whalen, B J; Goldschneider, I

1993-10-01

Quantitative adoptive transfer assays were developed to detect the precursors of TI-1, TI-2, and TD antigen-reactive B cells in rat lymphoid tissues. Studies on the immune responses in normal and athymic nude rats validate the use of TNP-lipopolysaccharide as a TI-1 antigen, TNP-Ficoll as a TI-2 antigen, and SRBC as a TD antigen in rats. The precursors to these immunologically competent B cells are detected, following transfer into irradiated histocompatible recipients, by their ability to generate expanded populations of antigen-reactive B cells capable of mounting antibody responses (splenic IgM plaque-forming cells) to these antigens. Maximal numbers of antigen-reactive B cells emerge in antigenically naive rats after an interval of 7-12 days following transfer of donor lymphoid cells and decline rapidly thereafter. The delayed responses in adoptive recipients reconstituted with spleen cells are proportional to the numbers of spleen cells transferred and are shown to be primarily donor derived using histocompatible Ig kappa chain alloantigen disparate rat strain combinations. The precursors of TI-1, TI-2, and TD antigen-reactive B cells are present in both donor spleen and bone marrow. However, precursor cells to TI-1 and TD antigens are largely absent from donor lymph node cells, whereas precursors to the TI-2 antigen are as prevalent in donor lymph node as in donor spleen. These results support the hypothesis that newly formed virginal B cells represent transient populations of precursor cells that undergo further proliferation and differentiation in the spleen before acquiring immunological competence. The results also suggest that the precursors of TI-2 antigen-reactive B cells differ developmentally from those of TI-1 and TD antigen-reactive B cells, and that the antigen-reactive progeny of these precursors require additional stimulation in order to join the pool of long-lived peripheral B cells.

Immune responses of B. malayi thioredoxin (TRX) and venom allergen homologue (VAH) chimeric multiple antigen for lymphatic filariasis.

PubMed

Anugraha, Gandhirajan; Jeyaprita, Parasurama Jawaharlal; Madhumathi, Jayaprakasam; Sheeba, Tamilvanan; Kaliraj, Perumal

2013-12-01

Although multiple vaccine strategy for lymphatic filariasis has provided tremendous hope, the choice of antigens used in combination has determined its success in the previous studies. Multiple antigens comprising key vaccine candidates from different life cycle stages would provide a promising strategy if the antigenic combination is chosen by careful screening. In order to analyze one such combination, we have used a chimeric construct carrying the well studied B. malayi antigens thioredoxin (BmTRX) and venom allergen homologue (BmVAH) as a fusion protein (TV) and evaluated its immune responses in mice model. The efficacy of fusion protein vaccine was explored in comparison with the single antigen vaccines and their cocktail. In mice, TV induced significantly high antibody titer of 1,28,000 compared to cocktail vaccine TRX+VAH (50,000) and single antigen vaccine TRX (16,000) or VAH (50,000). Furthermore, TV elicited higher level of cellular proliferative response together with elevated levels of IFN-γ, IL-4 and IL-5 indicating a Th1/Th2 balanced response. The isotype antibody profile showed significantly high level of IgG1 and IgG2b confirming the balanced response elicited by TV. Immunization with TV antigen induced high levels of both humoral and cellular immune responses compared to either cocktail or antigen given alone. The result suggests that TV is highly immunogenic in mice and hence the combination needs to be evaluated for its prophylactic potential.

Protection of rhesus macaques against inhalational anthrax with a Bacillus anthracis capsule conjugate vaccine.

PubMed

Chabot, Donald J; Ribot, Wilson J; Joyce, Joseph; Cook, James; Hepler, Robert; Nahas, Debbie; Chua, Jennifer; Friedlander, Arthur M

2016-07-25

The efficacy of currently licensed anthrax vaccines is largely attributable to a single Bacillus anthracis immunogen, protective antigen. To broaden protection against possible strains resistant to protective antigen-based vaccines, we previously developed a vaccine in which the anthrax polyglutamic acid capsule was covalently conjugated to the outer membrane protein complex of Neisseria meningitidis serotype B and demonstrated that two doses of 2.5μg of this vaccine conferred partial protection of rhesus macaques against inhalational anthrax . Here, we demonstrate complete protection of rhesus macaques against inhalational anthrax with a higher 50μg dose of the same capsule conjugate vaccine. These results indicate that B. anthracis capsule is a highly effective vaccine component that should be considered for incorporation in future generation anthrax vaccines. Published by Elsevier Ltd.

[Expression, purification and protective antigen analysis of cell wall protein MRP of Streptococcus suis type 2].

PubMed

Wang, Ping-ping; Pian, Ya-ya; Yuan, Yuan; Zheng, Yu-ling; Jiang, Yong-qiang; Xiong, Zheng-ying

2012-02-01

To amplify the mrp gene of Streptococcus suis type 2 05ZYH33, express it in E.coli BL21 in order to acquire high purity recombinant protein MRP, then evaluate the protective antigen of recombinant protein MRP. Using PCR technology to obtain the product of mrp gene of 05ZYH33, and then cloned it into the expression vector pET28a(+). The recombinant protein was purified by affinity chromatography, later immunized New Zealand rabbit to gain anti-serum, then test the anti-serum titer by ELISA. The opsonophagocytic killing test demonstrated the abilities of protective antigen of MRP. The truncated of MRP recombinant protein in E.coli BL21 expressed by inclusion bodies, and purified it in high purity. After immunoprotection, the survival condition of CD-1 was significantly elevated. The survival rate of wild-type strain 05ZYH33 in blood was apparently decreased after anti-serum opsonophagocyticed, but the mutant delta; MRP showed no differences. MRP represent an important protective antigen activity.

Use of a Molecular Decoy to Segregate Transport from Antigenicity in the FrpB Iron Transporter from Neisseria meningitidis

PubMed Central

Saleem, Muhammad; Prince, Stephen M.; Rigby, Stephen E. J.; Imran, Muhammad; Patel, Hema; Chan, Hannah; Sanders, Holly; Maiden, Martin C. J.; Feavers, Ian M.; Derrick, Jeremy P.

2013-01-01

FrpB is an outer membrane transporter from Neisseria meningitidis, the causative agent of meningococcal meningitis. It is a member of the TonB-dependent transporter (TBDT) family and is responsible for iron uptake into the periplasm. FrpB is subject to a high degree of antigenic variation, principally through a region of hypervariable sequence exposed at the cell surface. From the crystal structures of two FrpB antigenic variants, we identify a bound ferric ion within the structure which induces structural changes on binding which are consistent with it being the transported substrate. Binding experiments, followed by elemental analysis, verified that FrpB binds Fe3+ with high affinity. EPR spectra of the bound Fe3+ ion confirmed that its chemical environment was consistent with that observed in the crystal structure. Fe3+ binding was reduced or abolished on mutation of the Fe3+-chelating residues. FrpB orthologs were identified in other Gram-negative bacteria which showed absolute conservation of the coordinating residues, suggesting the existence of a specific TBDT sub-family dedicated to the transport of Fe3+. The region of antigenic hypervariability lies in a separate, external sub-domain, whose structure is conserved in both the F3-3 and F5-1 variants, despite their sequence divergence. We conclude that the antigenic sub-domain has arisen separately as a result of immune selection pressure to distract the immune response from the primary transport function. This would enable FrpB to function as a transporter independently of antibody binding, by using the antigenic sub-domain as a ‘molecular decoy’ to distract immune surveillance. PMID:23457610

Use of a molecular decoy to segregate transport from antigenicity in the FrpB iron transporter from Neisseria meningitidis.

PubMed

Saleem, Muhammad; Prince, Stephen M; Rigby, Stephen E J; Imran, Muhammad; Patel, Hema; Chan, Hannah; Sanders, Holly; Maiden, Martin C J; Feavers, Ian M; Derrick, Jeremy P

2013-01-01

FrpB is an outer membrane transporter from Neisseria meningitidis, the causative agent of meningococcal meningitis. It is a member of the TonB-dependent transporter (TBDT) family and is responsible for iron uptake into the periplasm. FrpB is subject to a high degree of antigenic variation, principally through a region of hypervariable sequence exposed at the cell surface. From the crystal structures of two FrpB antigenic variants, we identify a bound ferric ion within the structure which induces structural changes on binding which are consistent with it being the transported substrate. Binding experiments, followed by elemental analysis, verified that FrpB binds Fe(3+) with high affinity. EPR spectra of the bound Fe(3+) ion confirmed that its chemical environment was consistent with that observed in the crystal structure. Fe(3+) binding was reduced or abolished on mutation of the Fe(3+)-chelating residues. FrpB orthologs were identified in other Gram-negative bacteria which showed absolute conservation of the coordinating residues, suggesting the existence of a specific TBDT sub-family dedicated to the transport of Fe(3+). The region of antigenic hypervariability lies in a separate, external sub-domain, whose structure is conserved in both the F3-3 and F5-1 variants, despite their sequence divergence. We conclude that the antigenic sub-domain has arisen separately as a result of immune selection pressure to distract the immune response from the primary transport function. This would enable FrpB to function as a transporter independently of antibody binding, by using the antigenic sub-domain as a 'molecular decoy' to distract immune surveillance.

African swine fever virus serotype-specific proteins are significant protective antigens for African swine fever.

PubMed

Burmakina, G; Malogolovkin, A; Tulman, E R; Zsak, L; Delhon, G; Diel, D G; Shobogorov, N M; Morgunov, Yu P; Morgunov, S Yu; Kutish, G F; Kolbasov, D; Rock, D L

2016-07-01

African swine fever (ASF) is an emerging disease threat for the swine industry worldwide. No ASF vaccine is available and progress is hindered by lack of knowledge concerning the extent of ASFV strain diversity and the viral antigens conferring type-specific protective immunity in pigs. Available data from vaccination/challenge experiments in pigs indicate that ASF protective immunity may be haemadsorption inhibition (HAI) serotype-specific. Recently, we have shown that two ASFV proteins, CD2v (EP402R) and C-type lectin (EP153R), are necessary and sufficient for mediating HAI serological specificity (Malogolovkin et al., 2015).. Here, using ASFV inter-serotypic chimeric viruses and vaccination/challenge experiments in pigs, we demonstrate that serotype-specific CD2v and/or C-type lectin proteins are important for protection against homologous ASFV infection. Thus, these viral proteins represent significant protective antigens for ASFV that should be targeted in future vaccine design and development. Additionally, these data support the concept of HAI serotype-specific protective immunity.

[HLA A, B, C and DR antigens in a urban population from Santiago of Chile].

PubMed

Rodríguez, L; Scagliotti, P; Quiroga, T

1993-05-01

HLA antigens vary in different ethnical groups and in Chile there are no reports on the frequency of these antigens in a normal representative population. The few existing studies are of indigenous populations and control groups, without including HLA-DR antigens. Therefore, the aim of this study was to study the frequency of HLA A, B and C antigens in 349 individuals and HLA-DR in 257, using the microlymphocytotoxicity method, and compared the results with those on normal caucasian populations (Europe and USA). Significant differences were found for 7 antigens of group A, 10 of group B, 4 of group C and 6 of group DR. The observed difference allow us to conclude that the population from Santiago has a distinct HLA antigen distribution. This fact must be bore in mind future studies in genetics, paternity or autoimmune diseases.

Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation.

PubMed

Yao, Yushi; Li, Hui; Ding, Jie; Xia, Yixin; Wang, Lei

2017-11-01

Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM), which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm) cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.

Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation

PubMed Central

Yao, Yushi; Li, Hui; Ding, Jie; Xia, Yixin

2017-01-01

Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including Listeria monocytogenes (LM), which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm) cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation ex vivo. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy. PMID:29155896

Multiepitope fusion antigen induces broadly protective antibodies that prevent adherence of Escherichia coli strains expressing colonization factor antigen I (CFA/I), CFA/II, and CFA/IV.

PubMed

Ruan, Xiaosai; Knudsen, David E; Wollenberg, Katie M; Sack, David A; Zhang, Weiping

2014-02-01

Diarrhea is the second leading cause of death in children younger than 5 years and continues to be a major threat to global health. Enterotoxigenic Escherichia coli (ETEC) strains are the most common bacteria causing diarrhea in developing countries. ETEC strains are able to attach to host small intestinal epithelial cells by using bacterial colonization factor antigen (CFA) adhesins. This attachment helps to initiate the diarrheal disease. Vaccines that induce antiadhesin immunity to block adherence of ETEC strains that express immunologically heterogeneous CFA adhesins are expected to protect against ETEC diarrhea. In this study, we created a CFA multiepitope fusion antigen (MEFA) carrying representative epitopes of CFA/I, CFA/II (CS1, CS2, and CS3), and CFA/IV (CS4, CS5, and CS6), examined its immunogenicity in mice, and assessed the potential of this MEFA as an antiadhesin vaccine against ETEC. Mice intraperitoneally immunized with this CFA MEFA exhibited no adverse effects and developed immune responses to CFA/I, CFA/II, and CFA/IV adhesins. Moreover, after incubation with serum of the immunized mice, ETEC or E. coli strains expressing CFA/I, CFA/II, or CFA/IV adhesins were significantly inhibited in adherence to Caco-2 cells. Our results indicated this CFA MEFA elicited antibodies that not only cross-reacted to CFA/I, CFA/II and CFA/IV adhesins but also broadly inhibited adherence of E. coli strains expressing these seven adhesins and suggested that this CFA MEFA could be a candidate to induce broad-spectrum antiadhesin protection against ETEC diarrhea. Additionally, this antigen construction approach (creating an MEFA) may be generally used in vaccine development against heterogenic pathogens.

A Recombinant Raccoon Poxvirus Vaccine Expressing both Yersinia pestis F1 and Truncated V Antigens Protects Animals against Lethal Plague

PubMed Central

Rocke, Tonie E.; Kingstad-Bakke, Brock; Berlier, Willy; Osorio, Jorge E.

2014-01-01

In previous studies, we demonstrated in mice and prairie dogs that simultaneous administration of two recombinant raccoon poxviruses (rRCN) expressing Yersinia pestis antigens (F1 and V307—a truncated version of the V protein) provided superior protection against plague challenge compared to individual single antigen constructs. To reduce costs of vaccine production and facilitate implementation of a sylvatic plague vaccine (SPV) control program for prairie dogs, a dual antigen construct is more desirable. Here we report the construction and characterization of a novel RCN-vectored vaccine that simultaneously expresses both F1 and V307 antigens. This dual antigen vaccine provided similar levels of protection against plague in both mice and prairie dogs as compared to simultaneous administration of the two single antigen constructs and was also shown to protect mice against an F1 negative strain of Y. pestis. The equivalent safety, immunogenicity and efficacy profile of the dual RCN-F1/V307 construct warrants further evaluation in field efficacy studies in sylvatic plague endemic areas. PMID:26344891

A recombinant raccoon poxvirus vaccine expressing both Yersinia pestis F1 and truncated V antigens protects animals against lethal plague.

USGS Publications Warehouse

Rocke, Tonie E.; Kingstad-Bakke, B; Berlier, W; Osorio, J.E.

2014-01-01

In previous studies, we demonstrated in mice and prairie dogs that simultaneous administration of two recombinant raccoon poxviruses (rRCN) expressing Yersinia pestis antigens (F1 and V307-a truncated version of the V protein) provided superior protection against plague challenge compared to individual single antigen constructs. To reduce costs of vaccine production and facilitate implementation of a sylvatic plague vaccine (SPV) control program for prairie dogs, a dual antigen construct is more desirable. Here we report the construction and characterization of a novel RCN-vectored vaccine that simultaneously expresses both F1 and V307 antigens. This dual antigen vaccine provided similar levels of protection against plague in both mice and prairie dogs as compared to simultaneous administration of the two single antigen constructs and was also shown to protect mice against an F1 negative strain of Y. pestis.. The equivalent safety, immunogenicity and efficacy profile of the dual RCN-F1/V307 construct warrants further evaluation in field efficacy studies in sylvatic plague endemic areas.

Induction of protection against leishmaniasis in susceptible BALB/c mice using simple DOTAP cationic nanoliposomes containing soluble Leishmania antigen (SLA).

PubMed

Firouzmand, Hengameh; Badiee, Ali; Khamesipour, Ali; Heravi Shargh, Vahid; Alavizadeh, Seyedeh Hoda; Abbasi, Azam; Jaafari, Mahmoud Reza

2013-12-01

A suitable adjuvant and delivery system are needed to develop an effective vaccine against leishmaniasis. To induce a Th1 type of response and protection in BALB/c mice against Leishmania major infection, 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) nanoliposomes bearing an intrinsic adjuvanticity, were used as an antigen delivery system and immunoadjuvant for soluble Leishmania antigens (SLA). DOTAP liposomes containing different concentrations of SLA were prepared by using lipid film method followed by sonication. The prepared vesicles showed a diameter of about 100nm, a positive zeta potential and approximately 70% encapsulation efficiency of SLA. BALB/c mice were immunized subcutaneously (SC), three times in a 3-week interval with different concentrations of liposomal SLA (12.5, 25, and 50μg of SLA/50μl/mice), free SLA and as well as free liposome. The group of mice received 50μg of SLA in DOTAP-nanoliposomes showed a significantly (p<0.001) smaller footpad swelling and the lowest spleen and footpad parasite burden after the challenge. This group also showed the highest IFN-γ production compared to the other groups, lower IL-4 level and higher IgG2a antibody titer. Taken together, the results indicated that simple DOTAP nanoliposome containing 1μg/μl SLA are appropriate delivery systems to induce a Th1 type of immune response and protection against L. major infection in BALB/c mice. Copyright © 2013 Elsevier B.V. All rights reserved.

Hepatitis B virus core antigen: synthesis in Escherichia coli and application in diagnosis.

PubMed Central

Stahl, S; MacKay, P; Magazin, M; Bruce, S A; Murray, K

1982-01-01

Fragments of hepatitis B virus DNA cloned in plasmid pBR322 carrying the gene for the viral core antigen have been placed under the control of the lac promoter of Escherichia coli. Several of the new recombinants direct higher levels of synthesis of the antigen, but the degree of enhancement varies with the different structures of the plasmids and hence the mRNAs produced. The antigen in crude bacterial lysates is a satisfactory diagnostic reagent for antibodies to the core antigen in serum samples. Images PMID:7041126

Immunogenicity of DNA Vaccine against H5N1 Containing Extended Kappa B Site: In Vivo Study in Mice and Chickens

PubMed Central

Redkiewicz, Patrycja; Stachyra, Anna; Sawicka, Róz∙a; Bocian, Katarzyna; Góra-Sochacka, Anna; Kosson, Piotr; Sirko, Agnieszka

2017-01-01

Influenza is one of the most important illnesses in the modern world, causing great public health losses each year due to the lack of medication and broadly protective, long-lasting vaccines. The development of highly immunogenic and safe vaccines is currently one of the major problems encountered in efficient influenza prevention. DNA vaccines represent a novel and powerful alternative to the conventional vaccine approaches. To improve the efficacy of the DNA vaccine against influenza H5N1, we inserted three repeated kappa B (κB) motifs, separated by a 5-bp nucleotide spacer, upstream of the cytomegalovirus promoter and downstream of the SV40 late polyadenylation signal. The κB motif is a specific DNA element (10pb-long) recognized by one of the most important transcription factors NFκB. NFκB is present in almost all animal cell types and upon cell stimulation under a variety of pathogenic conditions. NFκB is released from IκB and translocates to the nucleus and binds to κB sites, thereby leading to enhanced transcription and expression of downstream genes. We tested the variants of DNA vaccine with κB sites flanking the antigen expression cassette and without such sites in two animal models: chickens (broilers and layers) and mice (BALB/c). In chickens, the variant with κB sites stimulated stronger humoral response against the target antigen. In mice, the differences in humoral response were less apparent. Instead, it was possible to spot several gene expression differences in the spleens isolated from mice immunized with both variants. The results of our study indicate that modification of the sequence outside of the sequence encoding the antigen might enhance the immune response to the target but understanding the mechanisms responsible for this process requires further analysis. PMID:28883819

A Replication-Defective Human Type 5 Adenovirus-Based Trivalent Vaccine Confers Complete Protection against Plague in Mice and Nonhuman Primates.

PubMed

Sha, Jian; Kirtley, Michelle L; Klages, Curtis; Erova, Tatiana E; Telepnev, Maxim; Ponnusamy, Duraisamy; Fitts, Eric C; Baze, Wallace B; Sivasubramani, Satheesh K; Lawrence, William S; Patrikeev, Igor; Peel, Jennifer E; Andersson, Jourdan A; Kozlova, Elena V; Tiner, Bethany L; Peterson, Johnny W; McWilliams, David; Patel, Snehal; Rothe, Eric; Motin, Vladimir L; Chopra, Ashok K

2016-07-01

Currently, no plague vaccine exists in the United States for human use. The capsular antigen (Caf1 or F1) and two type 3 secretion system (T3SS) components, the low-calcium-response V antigen (LcrV) and the needle protein YscF, represent protective antigens of Yersinia pestis We used a replication-defective human type 5 adenovirus (Ad5) vector and constructed recombinant monovalent and trivalent vaccines (rAd5-LcrV and rAd5-YFV) that expressed either the codon-optimized lcrV or the fusion gene designated YFV (consisting of ycsF, caf1, and lcrV). Immunization of mice with the trivalent rAd5-YFV vaccine by either the intramuscular (i.m.) or the intranasal (i.n.) route provided protection superior to that with the monovalent rAd5-LcrV vaccine against bubonic and pneumonic plague when animals were challenged with Y. pestis CO92. Preexisting adenoviral immunity did not diminish the protective response, and the protection was always higher when mice were administered one i.n. dose of the trivalent vaccine (priming) followed by a single i.m. booster dose of the purified YFV antigen. Immunization of cynomolgus macaques with the trivalent rAd5-YFV vaccine by the prime-boost strategy provided 100% protection against a stringent aerosol challenge dose of CO92 to animals that had preexisting adenoviral immunity. The vaccinated and challenged macaques had no signs of disease, and the invading pathogen rapidly cleared with no histopathological lesions. This is the first report showing the efficacy of an adenovirus-vectored trivalent vaccine against pneumonic plague in mouse and nonhuman primate (NHP) models. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Freeze-thaw stress of Alhydrogel ® alone is sufficient to reduce the immunogenicity of a recombinant hepatitis B vaccine containing native antigen.

PubMed

Clapp, Tanya; Munks, Michael W; Trivedi, Ruchit; Kompella, Uday B; Braun, LaToya Jones

2014-06-24

Preventing losses in vaccine potency due to accidental freezing has recently become a topic of interest for improving vaccines. All vaccines with aluminum-containing adjuvants are susceptible to such potency losses. Recent studies have described excipients that protect the antigen from freeze-induced inactivation, prevent adjuvant agglomeration and retain potency. Although these strategies have demonstrated success, they do not provide a mechanistic understanding of freeze-thaw (FT) induced potency losses. In the current study, we investigated how adjuvant frozen in the absence of antigen affects vaccine immunogenicity and whether preventing damage to the freeze-sensitive recombinant hepatitis B surface antigen (rHBsAg) was sufficient for maintaining vaccine potency. The final vaccine formulation or Alhydrogel(®) alone was subjected to three FT-cycles. The vaccines were characterized for antigen adsorption, rHBsAg tertiary structure, particle size and charge, adjuvant elemental content and in-vivo potency. Particle agglomeration of either vaccine particles or adjuvant was observed following FT-stress. In vivo studies demonstrated no statistical differences in IgG responses between vaccines with FT-stressed adjuvant and no adjuvant. Adsorption of rHBsAg was achieved; regardless of adjuvant treatment, suggesting that the similar responses were not due to soluble antigen in the frozen adjuvant-containing formulations. All vaccines with adjuvant, including the non-frozen controls, yielded similar, blue-shifted fluorescence emission spectra. Immune response differences could not be traced to differences in the tertiary structure of the antigen in the formulations. Zeta potential measurements and elemental content analyses suggest that FT-stress resulted in a significant chemical alteration of the adjuvant surface. This data provides evidence that protecting a freeze-labile antigen from subzero exposure is insufficient to maintain vaccine potency. Future studies should

The role of complement receptor positive and complement receptor negative B cells in the primary and secondary immune response to thymus independent type 2 and thymus dependent antigens.

PubMed

Lindsten, T; Yaffe, L J; Thompson, C B; Guelde, G; Berning, A; Scher, I; Kenny, J J

1985-05-01

Both complement receptor positive (CR+) and complement receptor negative (CR-) B cells have been shown to be involved in the primary immune response to PC-Hy (phosphocholine conjugated hemocyanin), a thymus dependent (TD) antigen which preferentially induces antibody secretion in Lyb-5+ B cells during a primary adoptive transfer assay. CR+ and CR- B cells also responded in a primary adoptive transfer assay to TNP-Ficoll, a thymus independent type 2 (TI-2) antigen which activates only Lyb-5+ B cells. When the secondary immune response to PC-Hy and TNP-Ficoll were analyzed, it was found that most of the immune memory to both antigens was present in the CR- B cell subset. The CR- B cell subset also dominated the secondary immune response to PC-Hy in immune defective (CBA/N X DBA/2N)F1 male mice. These data indicate that CR- B cells dominate the memory response in both the Lyb-5+ and Lyb-5- B cell subsets of normal and xid immune defective mice and suggest that Lyb-5+ and Lyb-5- B cells can be subdivided into CR+ and CR- subsets.

Anti-human neutrophil antigen-1a, -1b, and -2 antibodies in neonates and children with immune neutropenias analyzed by extracted granulocyte antigen immunofluorescence assay.

PubMed

Onodera, Rie; Kurita, Emi; Taniguchi, Kikuyo; Karakawa, Shuhei; Okada, Satoshi; Kihara, Hirotaka; Fujii, Teruhisa; Kobayashi, Masao

2017-11-01

Anti-human neutrophil antigen (HNA) antibodies have been implicated in the development of neonatal alloimmune neutropenia (NAN) and autoimmune neutropenia (AIN). There are many conventional assay methods that detect anti-HNA antibodies. However, a method to measure multiple samples and detect several anti-HNA antibodies simultaneously is needed. We developed a new method, the extracted granulocyte antigen immunofluorescence assay (EGIFA), to analyze anti-HNA-1a, -1b, and -2 antibodies in sera. The results obtained by EGIFA were evaluated in comparison with those from several standard assay methods. Anti-HNA antibodies in serum samples from nine familial cases with suspected NAN (n = 19) and children with suspected AIN (n = 88) were also measured by EGIFA. The evaluation of nine serum samples with anti-HNA antibodies suggested that EGIFA demonstrated equivalent specificity and superior sensitivity to monoclonal antibody-specific immobilization of granulocyte antigens and had comparable sensitivity to the granulocyte indirect immunofluorescence test. EGIFA successfully detected anti-HNA-1a or -1b antibodies in seven of nine familial cases with suspected NAN. EGIFA detected anti-HNA antibodies in 40.9% of children with suspected AIN. Among them, isolated anti-HNA-1a or -1b antibody was detected in 4.5 or 12.5% of children, respectively, and anti-HNA-2 antibody was identified in 3.4% of children. The 30.8% (16 of 52) of children negative for anti-HNA antibody by EGIFA were positive for anti-HLA antibody. EGIFA facilitated the measurement of anti-HNA-1a, -1b, and/or -2 antibodies in sera. The prompt measurement of anti-HNA antibodies will improve the diagnosis and clinical management of patients with suspected NAN or AIN. © 2017 AABB.

BCR-crosslinking induces a transcription of protein phosphatase component G5PR that is required for mature B-cell survival

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

Huq Ronny, Faisal Mahmudul; Igarashi, Hideya; Core Research for Evolutional Science and Technology

2006-02-03

BCR-crosslinking triggers activation-induced cell death (AICD) selectively in the restricted stage of B-cell differentiation. We examined the transcription of a protein phosphatase subunit G5PR in immature and mature B-cells, because absence of this factor augmented cell sensitivity to AICD, associated with increased activation of JNK and Bim. BCR-crosslinking-induced G5pr transcription in AICD-resistant mature splenic IgM{sup lo}IgD{sup hi} B-cells but not in AICD susceptible immature IgM{sup hi}IgD{sup lo} B-cells. Thus, G5pr induction correlated with the prevention of AICD; High in mature splenic CD23{sup hi} B-cells but low in immature B-cells of neonatal mice, sub-lethally irradiated mice, or xid mice. Lack ofmore » G5pr upregulation was associated with the prolonged activation of JNK. The G5pr cDNA transfection protected an immature B-cell line WEHI-231 from BCR-mediated AICD. The differential expression of G5PR might be responsible for the antigen-dependent selection of B-cells.« less

The immunogenicity of Echinococcus granulosus antigen 5 is determined by its post-translational modifications.

PubMed

Lorenzo, C; Last, J A; González-Sapienza, G G

2005-11-01

Since its early introduction as a marker for the immunodiagnosis of hydatid disease, antigen 5 (Ag5) has been regarded as one of the more relevant antigens of Echinococcus granulosus, and it is still widely used in different confirmation techniques. In this work we prepared 2 recombinant forms of the antigen, namely, rAg5 (corresponding to the unprocessed polypeptide chain of the antigen) and rAg5-38s (corresponding to its 38 kDa subunit). Their antigenicities were compared to that of the native antigen using a human serum collection. There was a major drop in the reactivity of the sera, particularly against rAg5-38s, which was confirmed by analysis of the cross-reactivity of 2 panels of monoclonal antibodies specific for rAg5-38s and the native antigen. Using the chemically deglycosylated native antigen, we demonstrated that the reduced antigenicity of the recombinants is due to the loss of the sugar determinants, and not to their misfolding. Inhibition experiments using phosphorylcholine confirmed that this moiety also contributes to the reactivity of the antigen, but to a much lesser extent. The presence of immunodominant highly cross-reactive glycan moieties in the Ag5 molecule may involve a parasite evasion mechanism.

Antigen-Presenting Intratumoral B Cells Affect CD4+ TIL Phenotypes in Non-Small Cell Lung Cancer Patients.

PubMed

Bruno, Tullia C; Ebner, Peggy J; Moore, Brandon L; Squalls, Olivia G; Waugh, Katherine A; Eruslanov, Evgeniy B; Singhal, Sunil; Mitchell, John D; Franklin, Wilbur A; Merrick, Daniel T; McCarter, Martin D; Palmer, Brent E; Kern, Jeffrey A; Slansky, Jill E

2017-10-01

Effective immunotherapy options for patients with non-small cell lung cancer (NSCLC) are becoming increasingly available. The immunotherapy focus has been on tumor-infiltrating T cells (TILs); however, tumor-infiltrating B cells (TIL-Bs) have also been reported to correlate with NSCLC patient survival. The function of TIL-Bs in human cancer has been understudied, with little focus on their role as antigen-presenting cells and their influence on CD4 + TILs. Compared with other immune subsets detected in freshly isolated primary tumors from NSCLC patients, we observed increased numbers of intratumoral B cells relative to B cells from tumor-adjacent tissues. Furthermore, we demonstrated that TIL-Bs can efficiently present antigen to CD4 + TILs and alter the CD4 + TIL phenotype using an in vitro antigen-presentation assay. Specifically, we identified three CD4 + TIL responses to TIL-Bs, which we categorized as activated, antigen-associated, and nonresponsive. Within the activated and antigen-associated CD4 + TIL population, activated TIL-Bs (CD19 + CD20 + CD69 + CD27 + CD21 + ) were associated with an effector T-cell response (IFNγ + CD4 + TILs). Alternatively, exhausted TIL-Bs (CD19 + CD20 + CD69 + CD27 - CD21 - ) were associated with a regulatory T-cell phenotype (FoxP3 + CD4 + TILs). Our results demonstrate a new role for TIL-Bs in NSCLC tumors in their interplay with CD4 + TILs in the tumor microenvironment, establishing them as a potential therapeutic target in NSCLC immunotherapy. Cancer Immunol Res; 5(10); 898-907. ©2017 AACR . ©2017 American Association for Cancer Research.

Treating B-cell cancer with T cells expressing anti-CD19 chimeric antigen receptors.

PubMed

Kochenderfer, James N; Rosenberg, Steven A

2013-05-01

Most B-cell malignancies express CD19, and a majority of patients with B-cell malignancies are not cured by current standard therapies. Chimeric antigen receptors (CARs) are fusion proteins consisting of antigen recognition moieties and T-cell activation domains. T cells can be genetically modified to express CARs, and adoptive transfer of anti-CD19 CAR T cells is now being tested in clinical trials. Effective clinical treatment with anti-CD19 CAR T cells was first reported in 2010 after a patient with advanced-stage lymphoma treated at the NCI experienced a partial remission of lymphoma and long-term eradication of normal B cells. Additional patients have subsequently obtained long-term remissions of advanced-stage B-cell malignancies after infusions of anti-CD19 CAR T cells. Long-term eradication of normal CD19(+) B cells from patients receiving infusions of anti-CD19 CAR T cells demonstrates the potent antigen-specific activity of these T cells. Some patients treated with anti-CD19 CAR T cells have experienced acute adverse effects, which were associated with increased levels of serum inflammatory cytokines. Although anti-CD19 CAR T cells are at an early stage of development, the potent antigen-specific activity observed in patients suggests that infusions of anti-CD19 CAR T cells might become a standard therapy for some B-cell malignancies.

Identification of novel rabbit hemorrhagic disease virus B-cell epitopes and their interaction with host histo-blood group antigens.

PubMed

Song, Yanhua; Wang, Fang; Fan, Zhiyu; Hu, Bo; Liu, Xing; Wei, Houjun; Xue, Jiabin; Xu, Weizhong; Qiu, Rulong

2016-02-01

Rabbit haemorrhagic disease, caused by rabbit hemorrhagic disease virus (RHDV), results in the death of millions of adult rabbits worldwide, with a mortality rate that exceeds 90%. The sole capsid protein, VP60, is divided into shell (S) and protruding (P) domains, and the more exposed P domain likely contains determinants for cell attachment and antigenic diversity. Nine mAbs against VP60 were screened and identified. To map antigenic epitopes, a set of partially overlapping and consecutive truncated proteins spanning VP60 were expressed. The minimal determinants of the linear B-cell epitopes of VP60 in the P domain, N(326)PISQV(331), D(338)MSFV(342) and K(562)STLVFNL(569), were recognized by one (5H3), four (1B8, 3D11, 4C2 and 4G2) and four mAbs (1D4, 3F7, 5G2 and 6B2), respectively. Sequence alignment showed epitope D(338)MSFV(342) was conserved among all RHDV isolates. Epitopes N(326)PISQV(331) and K(562)STLVFNL(569) were highly conserved among RHDV G1-G6 and variable in RHDV2 strains. Previous studies demonstrated that native viral particles and virus-like particles (VLPs) of RHDV specifically bound to synthetic blood group H type 2 oligosaccharides. We established an oligosaccharide-based assay to analyse the binding of VP60 and epitopes to histo-blood group antigens (HBGAs). Results showed VP60 and its epitopes (aa 326-331 and 338-342) in the P2 subdomain could significantly bind to blood group H type 2. Furthermore, mAbs 1B8 and 5H3 could block RHDV VLP binding to synthetic H type 2. Collectively, these two epitopes might play a key role in the antigenic structure of VP60 and interaction of RHDV and HBGA.

CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production

PubMed Central

Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A.; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C.; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten; Westendorf, Astrid M.; Häussinger, Dieter; Lang, Florian; Dittmer, Ulf; Küppers, Ralf; Recher, Mike; Hardt, Cornelia; Scheffrahn, Inka; Beauchemin, Nicole; Göthert, Joachim R.; Singer, Bernhard B.; Lang, Philipp A.; Lang, Karl S.

2015-01-01

B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1−/− mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1−/− mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. PMID:25692415

Antigenic diversity of H5 highly pathogenic avian influenza viruses of clade 2.3.4.4 isolated in Asia.

PubMed

Ohkawara, Ayako; Okamatsu, Masatoshi; Ozawa, Makoto; Chu, Duc-Huy; Nguyen, Lam Thanh; Hiono, Takahiro; Matsuno, Keita; Kida, Hiroshi; Sakoda, Yoshihiro

2017-05-01

H5 highly pathogenic avian influenza viruses (HPAIV) have spread in both poultry and wild birds since late 2003. Continued circulation of HPAIV in poultry in several regions of the world has led to antigenic drift. In the present study, we analyzed the antigenic properties of H5 HPAIV isolated in Asia using four neutralizing mAbs recognizing hemagglutinin, which were established using A/chicken/Kumamoto/1-7/2014 (H5N8), belonging to clade 2.3.4.4 and also using polyclonal antibodies. Viruses of clades 1.1, 2.3.2.1, 2.3.4, and 2.3.4.4 had different reactivity patterns to the panel of mAbs, thereby indicating that the antigenicity of the viruses of clade 2.3.4.4 were similar but differed from the other clades. In particular, the antigenicity of the viruses of clade 2.3.4.4 differed from those of the viruses of clades 2.3.4 and 2.3.2.1, which suggests that the recent H5 HPAIV have further evolved antigenically divergent. In addition, reactivity of antiserum suggests that the antigenicity of viruses of clade 2.3.4.4 differed slightly among groups A, B, and C. Vaccines are still used in poultry in endemic countries, so the antigenicity of H5 HPAIV should be monitored continually to facilitate control of avian influenza. The panel of mAbs established in the present study will be useful for detecting antigenic drift in the H5 viruses that emerge from the current strains. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

Protective-antigen (PA) based anthrax vaccines confer protection against inhalation anthrax by precluding the establishment of a systemic infection

PubMed Central

Merkel, Tod J; Perera, Pin-Yu; Lee, Gloria M; Verma, Anita; Hiroi, Toyoko; Yokote, Hiroyuki; Waldmann, Thomas A; Perera, Liyanage P

2013-01-01

An intense effort has been launched to develop improved anthrax vaccines that confer rapid, long lasting protection preferably with an extended stability profile amenable for stockpiling. Protective antigen (PA)-based vaccines are most favored as immune responses directed against PA are singularly protective, although the actual protective mechanism remains to be unraveled. Herein we show that contrary to the prevailing view, an efficacious PA-based vaccine confers protection against inhalation anthrax by preventing the establishment of a toxin-releasing systemic infection. Equally importantly, antibodies measured by the in vitro lethal toxin neutralization activity assay (TNA) that is considered as a reliable correlate of protection, especially for PA protein-based vaccines adjuvanted with aluminum salts appear to be not absolutely essential for this protective immune response. PMID:23787486

Protective-antigen (PA) based anthrax vaccines confer protection against inhalation anthrax by precluding the establishment of a systemic infection.

PubMed

Merkel, Tod J; Perera, Pin-Yu; Lee, Gloria M; Verma, Anita; Hiroi, Toyoko; Yokote, Hiroyuki; Waldmann, Thomas A; Perera, Liyanage P

2013-09-01

An intense effort has been launched to develop improved anthrax vaccines that confer rapid, long lasting protection preferably with an extended stability profile amenable for stockpiling. Protective antigen (PA)-based vaccines are most favored as immune responses directed against PA are singularly protective, although the actual protective mechanism remains to be unraveled. Herein we show that contrary to the prevailing view, an efficacious PA-based vaccine confers protection against inhalation anthrax by preventing the establishment of a toxin-releasing systemic infection. Equally importantly, antibodies measured by the in vitro lethal toxin neutralization activity assay (TNA) that is considered as a reliable correlate of protection, especially for PA protein-based vaccines adjuvanted with aluminum salts appear to be not absolutely essential for this protective immune response.

Scaffolded Antigens in Yeast Cell Particle Vaccines Provide Protection against Systemic Polyoma Virus Infection.

PubMed

Tipper, Donald J; Szomolanyi-Tsuda, Eva

2016-01-01

Background. U65, a self-aggregating peptide scaffold, traps fused protein antigens in yeast cells. Conversion to Yeast Cell Particle (YCP) vaccines by partial removal of surface mannoproteins exposes β-glucan, mediating efficient uptake by antigen-presenting cells (APCs). YCP vaccines are inexpensive, capable of rapid large-scale production and have potential for both parenteral and oral use. Results. YCP processing by alkaline hydrolysis exposes up to 20% of the glucan but converts scaffolded antigen and internal yeast proteins into a common aggregate, preventing selective yeast protein removal. For U65-green fluorescent protein (GFP) or U65-Apolipoprotein A1 (ApoA1) subcutaneous vaccines, maximal IgG responses in mice required 10% glucan exposure. IgG responses to yeast proteins were 5-fold lower. Proteolytic mannoprotein removal produced YCPs with only 6% glucan exposure, insufficiently porous for selective removal of even native yeast proteins. Vaccine efficacy was reduced 10-fold. Current YCP formulations, therefore, are not suitable for human use but have considerable potential for use in feed animal vaccines. Significantly, a YCP vaccine expressing a GFP fusion to VP1, the murine polyoma virus major capsid protein, after either oral or subcutaneous administration, protected mice against an intraperitoneal polyoma virus challenge, reducing viral DNA levels in spleen and liver by >98%.

Induction of anti-HBs in HB vaccine nonresponders in vivo by hepatitis B surface antigen-pulsed blood dendritic cells.

PubMed

Fazle Akbar, Sk Md; Furukawa, Shinya; Yoshida, Osamu; Hiasa, Yoichi; Horiike, Norio; Onji, Morikazu

2007-07-01

Antigen-pulsed dendritic cells (DCs) are now used for treatment of patients with cancers, however, the efficacy of these DCs has never been evaluated for prophylactic purposes. The aim of this study was (1) to prepare hepatitis B surface antigen (HBsAg)-pulsed human blood DCs, (2) to assess immunogenicity of HBsAg-pulsed DCs in vitro and (3) to evaluate the efficacy of HBsAg-pulsed DCs in hepatitis B (HB) vaccine nonresponders. Human peripheral blood DCs were cultured with HBsAg to prepare HBsAg-pulsed DCs. The expression of immunogenic epitopes of HBsAg on HBsAg-pulsed DCs was assessed in vitro. Finally, HBsAg-pulsed DCs were administered, intradermally to six HB vaccine nonresponders and the levels of antibody to HBsAg (anti-HBs) in the sera were assessed. HB vaccine nonresponders did not exhibit features of immediate, early or delayed adverse reactions due to administration of HBsAg-pulsed DCs. Anti-HBs were detected in the sera of all HB vaccine nonresponders within 28 days after administration of HBsAg-pulsed DCs. This study opens a new field of application of antigen-pulsed DCs for prophylactic purposes when adequate levels of protective antibody cannot be induced by traditional vaccination approaches.

Leaf-Encapsulated Vaccines: Agroinfiltration and Transient Expression of the Antigen Staphylococcal Endotoxin B in Radish Leaves

PubMed Central

Liu, Pei-Feng; Wang, Yanhan; Ulrich, Robert G.; Simmons, Christopher W.; VanderGheynst, Jean S.; Gallo, Richard L.

2018-01-01

Transgene introgression is a major concern associated with transgenic plant-based vaccines. Agroinfiltration can be used to selectively transform nonreproductive organs and avoid introgression. Here, we introduce a new vaccine modality in which Staphylococcal enterotoxin B (SEB) genes are agroinfiltrated into radishes (Raphanw sativus L.), resulting in transient expression and accumulation of SEB in planta. This approach can simultaneously express multiple antigens in a single leaf. Furthermore, the potential of high-throughput vaccine production was demonstrated by simultaneously agroinfiltrating multiple radish leaves using a multichannel pipette. The expression of SEB was detectable in two leaf cell types (epidermal and guard cells) in agroinfiltrated leaves. ICR mice intranasally immunized with homogenized leaves agroinfiltrated with SEB elicited detectable antibody to SEB and displayed protection against SEB-induced interferon-gamma (IFN-γ) production. The concept of encapsulating antigens in leaves rather than purifying them for immunization may facilitate rapid vaccine production during an epidemic disease. PMID:29577048

NLRC5 deficiency protects against acute kidney injury in mice by mediating carcinoembryonic antigen-related cell adhesion molecule 1 signaling.

PubMed

Li, Quanxin; Wang, Ziying; Zhang, Yan; Zhu, Jiaqing; Li, Liang; Wang, Xiaojie; Cui, Xiaoyang; Sun, Yu; Tang, Wei; Gao, Chengjiang; Ma, Chunhong; Yi, Fan

2018-06-12

There is significant progress in understanding the structure and function of NLRC5, a member of the nucleotide oligomerization domain-like receptor family. However, in the context of MHC class I gene expression, the functions of NLRC5 in innate and adaptive immune responses beyond the regulation of MHC class I genes remain controversial and unresolved. In particular, the role of NLRC5 in the kidney is unknown. NLRC5 was significantly upregulated in the kidney from mice with renal ischemia/reperfusion injury. NLRC5 deficient mice significantly ameliorated renal injury as evidenced by decreased serum creatinine levels, improved morphological injuries, and reduced inflammatory responses versus wild type mice. Similar protective effects were also observed in cisplatin-induced acute kidney injury. Mechanistically, NLRC5 contributed to renal injury by promoting tubular epithelial cell apoptosis and reducing inflammatory responses were, at least in part, associated with the negative regulation of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). To determine the relative contribution of NLRC5 expression by parenchymal cells or leukocytes to renal damage during ischemia/reperfusion injury, we generated bone marrow chimeric mice. NLRC5 deficient mice engrafted with wild type hematopoietic cells had significantly lower serum creatinine and less tubular damage than wild type mice reconstituted with NLRC5 deficient bone marrow. This suggests that NLRC5 signaling in renal parenchymal cells plays the dominant role in mediating renal damage. Thus, modulation of the NLRC5-mediated pathway may have important therapeutic implications for patients with acute kidney injury. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

HLA typing associated with hepatitis B E antigen seroconversion in children with chronic hepatitis B virus infection: a long-term prospective sibling cohort study in Taiwan.

PubMed

Wu, Jia-Feng; Chen, Chen-Hsin; Hsieh, Rhong-Phong; Shih, Hsiang-Hung; Chen, Yi-Hau; Li, Chi-Rong; Chiang, Chih-Yao; Shau, Wen-Yi; Ni, Yen-Hsuan; Chen, Huey-Ling; Hsu, Hong-Yuan; Chang, Mei-Hwei

2006-05-01

To conduct a prospective cohort study to clarify the relationship between human leukocyte antigen (HLA) polymorphisms and the seroconversion of hepatitis B e antigen (HBeAg). In the prospective cohort study, 81 HBeAg-positive children with chronic hepatitis B virus (HBV) infection from 40 unrelated families were recruited and followed-up regularly for a mean period of 17.70 +/- 3.23 years. The association between HLA antigen and the age at HBeAg seroconversion was analyzed using Cox regression model with shared frailties under left truncation and right censorship. HLA-B61 and HLA-DQB1*0503 antigens predicted a higher HBeAg seroconversion rate (relative incidence = 6.17 and 3.22, P = .024 and .017, respectively). Within-family frailty in our sibling cohort study demonstrated a negligible or a low degree of within-family correlation with spontaneous HBeAg seroconversion in each HLA antigen. HLA class I antigen B61 and class II antigen DQB1*0503 are associated with earlier HBeAg seroconversion in Taiwanese children with chronic HBV infection.

17 CFR 240.15b5-1 - Extension of registration for purposes of the Securities Investor Protection Act of 1970 after...

Code of Federal Regulations, 2010 CFR

2010-04-01

... purposes of the Securities Investor Protection Act of 1970 after cancellation or revocation. 240.15b5-1... purposes of the Securities Investor Protection Act of 1970 after cancellation or revocation. Commission... member within the meaning of Section 3(a)(2) of the Securities Investor Protection Act of 1970 for...

Detection of hepatitis B surface antigen in pregnant women attending a public hospital for delivery: implication for vaccination strategy in Bangladesh.

PubMed

Rumi, M A; Begum, K; Hassan, M S; Hasan, S M; Azam, M G; Hasan, K N; Shirin, M; Khan, A K

1998-08-01

Routine antenatal hepatitis B surface antigen (HBsAg) screening and immunization of risk babies is very effective in preventing perinatal transmission of hepatitis B virus (HBV). We studied 1,800 parturients attending a public hospital to assess the rationale for such vaccination in Bangladesh. In one in every 29 deliveries (63 of 1,800 or 3.5%), the mother was found to be HBsAg positive. All were asymptomatic and many (41 of 63 or 65%) without risk factors would remain undetected if HBsAg screening were performed on selected groups. Most of the HBsAg-positive mothers (54 of 63 or 85.7%) were found to be chronic carriers and 30.2% (19 of 63) were also hepatitis B e antigen (HBeAg) positive, indicating high infectivity. Although 23 cord blood were positive for HBsAg or HBeAg, none were positive for IgM antibody to hepatitis B core antigen (IgM anti-HBc), suggesting transplacental transmission of the antigens rather than intrauterine infection. These findings are discussed in relation to the cost-effectiveness of routine prenatal screening and immunization of risk babies compared with universal infant immunization.

Homologous and heterologous antigenic matched vaccines containing different H5 hemagglutinins provide variable protection of chickens from the 2014 U.S. H5N8 and H5N2 clade 2.3.4.4 highly pathogenic avian influenza viruses.

PubMed

Kapczynski, Darrell R; Pantin-Jackwood, Mary J; Spackman, Erica; Chrzastek, Klaudia; Suarez, David L; Swayne, David E

2017-11-01

From December 2014 to June 2015, a novel H5 Eurasian A/goose/Guangdong (Gs/GD) lineage clade 2.3.4.4 high pathogenicity avian influenza (HPAI) virus caused the largest animal health emergency in US history resulting in mortality or culling of greater than 48 million poultry. The outbreak renewed interest in developing intervention strategies, including vaccines, for these newly emergent HPAI viruses. In these studies, several existing H5 vaccines or vaccine seed strains with varying genetic relatedness (85-100%) to the 2.3.4.4 HPAI viruses were evaluated for protection in poultry. Chickens received a single dose of either an inactivated whole H5 AI vaccine, or a recombinant fowl poxvirus or turkey herpesvirus-vectored vaccines with H5 AI hemagglutinin gene inserts followed by challenge with either a U.S. wild bird H5N8 (A/gyrfalcon/Washington/40188-6/2014) or H5N2 (A/northern pintail/Washington/40964/2014) clade 2.3.4.4 isolate. Results indicate that most inactivated H5 vaccines provided 100% protection from lethal effects of H5N8 or H5N2 challenge. In contrast, the recombinant live vectored vaccines only provided partial protection which ranged from 40 to 70%. Inactivated vaccine groups, in general, had lower number of birds shedding virus and at lower virus titers then the recombinant vaccine groups. Interestingly, prechallenge antibody titers using the HPAI challenge viruses as antigen in heterologous vaccine groups were typically low (≤2 log 2 ), yet the majority of these birds survived challenge. Taken together, these studies suggest that existing vaccines when used in a single immunization strategy may not provide adequate protection in poultry against the 2.3.4.4 HPAI viruses. Updating the H5 hemagglutinin to be genetically closer to the outbreak virus and/or using a prime-boost strategy may be necessary for optimal protection. Published by Elsevier Ltd.

Oral immunization of mice with gamma-irradiated Brucella neotomae induces protection against intraperitoneal and intranasal challenge with virulent B. abortus 2308.

PubMed

Dabral, Neha; Martha-Moreno-Lafont; Sriranganathan, Nammalwar; Vemulapalli, Ramesh

2014-01-01

Brucella spp. are Gram-negative, facultative intracellular coccobacilli that cause one of the most frequently encountered zoonosis worldwide. Humans naturally acquire infection through consumption of contaminated dairy and meat products and through direct exposure to aborted animal tissues and fluids. No vaccine against brucellosis is available for use in humans. In this study, we tested the ability of orally inoculated gamma-irradiated B. neotomae and B. abortus RB51 in a prime-boost immunization approach to induce antigen-specific humoral and cell mediated immunity and protection against challenge with virulent B. abortus 2308. Heterologous prime-boost vaccination with B. abortus RB51 and B. neotomae and homologous prime-boost vaccination of mice with B. neotomae led to the production of serum and mucosal antibodies specific to the smooth LPS. The elicited serum antibodies included the isotypes of IgM, IgG1, IgG2a, IgG2b and IgG3. All oral vaccination regimens induced antigen-specific CD4(+) and CD8(+) T cells capable of secreting IFN-γ and TNF-α. Upon intra-peritoneal challenge, mice vaccinated with B. neotomae showed the highest level of resistance against virulent B. abortus 2308 colonization in spleen and liver. Experiments with different doses of B. neotomae showed that all tested doses of 10(9), 10(10) and 10(11) CFU-equivalent conferred significant protection against the intra-peritoneal challenge. However, a dose of 10(11) CFU-equivalent of B. neotomae was required for affording protection against intranasal challenge as shown by the reduced bacterial colonization in spleens and lungs. Taken together, these results demonstrate the feasibility of using gamma-irradiated B. neotomae as an effective and safe oral vaccine to induce protection against respiratory and systemic infections with virulent Brucella.

Successful TB treatment induces B-cells expressing FASL and IL5RA mRNA.

PubMed

van Rensburg, Ilana C; Wagman, Chandre; Stanley, Kim; Beltran, Caroline; Ronacher, Katharina; Walzl, Gerhard; Loxton, Andre G

2017-01-10

Activated B-cells increase T-cell behaviour during autoimmune disease and other infections by means of cytokine production and antigen-presentation. Functional studies in experimental autoimmune encephalomyelitis (EAE) indicate that B-cell deficiencies, and a lack of IL10 and IL35 leads to a poor prognosis. We hypothesised that B-cells play a role during tuberculosis. We evaluated B-cell mRNA expression using real-time PCR from healthy community controls, individuals with other lung diseases and newly diagnosed untreated pulmonary TB patients at three different time points (diagnosis, month 2 and 6 of treatment).We show that FASLG, IL5RA, CD38 and IL4 expression was lower in B-cells from TB cases compared to healthy controls. The changes in expression levels of CD38 may be due to a reduced activation of B-cells from TB cases at diagnosis. By month 2 of treatment, there was a significant increase in the expression of APRIL and IL5RA in TB cases. Furthermore, after 6 months of treatment, APRIL, FASLG, IL5RA and CD19 were upregulated in B-cells from TB cases. The increase in the expression of APRIL and CD19 suggests that there may be restored activation of B-cells following anti-TB treatment. The upregulation of FASLG and IL5RA indicates that B-cells expressing regulatory genes may play an important role in the protective immunity against M.tb infection. Our results show that increased activation of B-cells is present following successful TB treatment, and that the expression of FASLG and IL5RA could potentially be utilised as a signature to monitor treatment response.

Nonclassical T Cells and Their Antigens in Tuberculosis

PubMed Central

De Libero, Gennaro; Singhal, Amit; Lepore, Marco; Mori, Lucia

2014-01-01

T cells that recognize nonpeptidic antigens, and thereby are identified as nonclassical, represent important yet poorly characterized effectors of the immune response. They are present in large numbers in circulating blood and tissues and are as abundant as T cells recognizing peptide antigens. Nonclassical T cells exert multiple functions including immunoregulation, tumor control, and protection against infections. They recognize complexes of nonpeptidic antigens such as lipid and glycolipid molecules, vitamin B2 precursors, and phosphorylated metabolites of the mevalonate pathway. Each of these antigens is presented by antigen-presenting molecules other than major histocompatibility complex (MHC), including CD1, MHC class I–related molecule 1 (MR1), and butyrophilin 3A1 (BTN3A1) molecules. Here, we discuss how nonclassical T cells participate in the recognition of mycobacterial antigens and in the mycobacterial-specific immune response. PMID:25059739

Epitope-cavities generated by molecularly imprinted films measure the coincident response to anthrax protective antigen and its segments.

PubMed

Tai, Dar-Fu; Jhang, Ming-Hong; Chen, Guan-Yu; Wang, Sue-Chen; Lu, Kuo-Hao; Lee, Yu-Der; Liu, Hsin-Tzu

2010-03-15

A molecularly imprinted film was fabricated, in the presence of epitope-peptides, onto a quartz crystal microbalance (QCM) chip. These five peptides are known linear or conformational epitopes of the anthrax protective antigen PA(83). Imprinting resulted in an epitope-cavity with affinity for the corresponding template. With the use of a basic monomer, the binding-effect was further enhanced increasing the affinity to nanomolar levels. The affinities of the peptide to their corresponding molecularly induced polymers (MIPs) were more closely related to the molecular weight of the analyte than to the number of residues. All epitope-cavities differentiated their epitope region on the protective antigen PA(83) as well as the corresponding furin cleavage fragments PA(63) and PA(20). The QCM chip differential response to the protective antigen fragment was observed in the picomolar range, thus demonstrating a method to manipulate protein on the surface with defined orientation.

Shigella IpaB and IpaD displayed on L. lactis bacterium-like particles induce protective immunity in adult and infant mice

PubMed Central

Heine, Shannon J.; Franco-Mahecha, Olga L.; Chen, Xiaotong; Choudhari, Shyamal; Blackwelder, William C.; van Roosmalen, Maarten L.; Leenhouts, Kees; Picking, Wendy L.; Pasetti, Marcela F.

2015-01-01

Shigella spp. are among the enteric pathogens with the highest attributable incidence of moderate-to-severe diarrhea in children under 5 years of age living in endemic areas. There are no vaccines available to prevent this disease. In this work, we investigated a new Shigella vaccine concept consisting of non-living, self-adjuvanted, Lactococcus lactis bacterium-like particles (BLP) displaying Shigella invasion plasmid antigen (Ipa) B and IpaD and examined its immunogenicity and protective efficacy in adult and newborn/infant mice immunized via the nasal route. Unique advantages of this approach include the potential for broad protection due to the highly conserved structure of the Ipas and the safety and practicality of a probiotic-based mucosal/adjuvant delivery platform. Immunization of adult mice with BLP-IpaB and BLP-IpaD (BLP-IpaB/D) induced high levels of Ipa-specific serum IgG and stool IgA in a dose-dependent manner. Immune responses and protection were enhanced by BLP delivery. Vaccine-induced serum antibodies exhibited opsonophagocytic and cytotoxic neutralizing activity, and IpaB/D IgG titers correlated with increased survival post-challenge. Ipa-specific antibody secreting cells were detected in nasal tissue and lungs, as well as IgG in bronchoalveolar lavage. Bone marrow cells produced IpaB/D-specific antibodies and contributed to protection after adoptive transfer. The BLP-IpaB/D vaccine conferred 90% and 80% protection against S. flexneri and S. sonnei, respectively. Mice immunized with BLP-IpaB/D as newborns also developed IpaB and IpaD serum antibodies; 90% were protected against S. flexneri and 44% against S. sonnei. The BLP-IpaB/D vaccine is a promising candidate for safe, practical and potentially effective immunization of children against shigellosis. PMID:25776843

15-HETE "modulates" expression of C3b receptor (CR1) antigen on peripheral blood B-lymphocytes.

PubMed

Cook, J; Delebassée, S; Aldigier, J C; Gualde, N; Kazatchkine, M

1986-08-01

We have studied the effect of the lipoxygenase metabolite, 15-HETE, on the expression of the human C3b receptor (CR1) by a B-lymphocyte enriched population of human peripheral blood leukocytes. The number of CR1 antigenic sites expressed by B-lymphocytes isolated from HLA typed donors was determined by equilibrium binding studies using an 125 I-labelled mouse monoclonal anti CR1 antibody before and after 16 hrs incubation in RPMI alone or containing 10(-6)M, 10(-7)M or 10(-8)M final concentration of 15-HETE. In B44- subjects CR1 expression on B cells increased 63% after incubation in RPMI alone. This increase was inhibited in the presence of 10(-6)M and 10(-7)M 15-HETE (23% and 30% increase respectively). In contrast, B44+ individuals showed a smaller increase in CR1 numbers when incubated in RPMI alone. In the presence of 15-HETE CR1 antigenic sites continued to increase. When B44+ subjects were classified as A29+ or A29-, donors that were A29+ B44+ accounted for the augmentation observed while A29- B44+ individuals did not differ from individuals that were A29- B44-.

Novel fusion proteins for the antigen-specific staining and elimination of B cell receptor-positive cell populations demonstrated by a tetanus toxoid fragment C (TTC) model antigen.

PubMed

Klose, Diana; Saunders, Ute; Barth, Stefan; Fischer, Rainer; Jacobi, Annett Marita; Nachreiner, Thomas

2016-02-17

In an earlier study we developed a unique strategy allowing us to specifically eliminate antigen-specific murine B cells via their distinct B cell receptors using a new class of fusion proteins. In the present work we elaborated our idea to demonstrate the feasibility of specifically addressing and eliminating human memory B cells. The present study reveals efficient adaptation of the general approach to selectively target and eradicate human memory B cells. In order to demonstrate the feasibility we engineered a fusion protein following the principle of recombinant immunotoxins by combining a model antigen (tetanus toxoid fragment C, TTC) for B cell receptor targeting and a truncated version of Pseudomonas aeruginosa exotoxin A (ETA') to induce apoptosis after cellular uptake. The TTC-ETA' fusion protein not only selectively bound to a TTC-reactive murine B cell hybridoma cell line in vitro but also to freshly isolated human memory B cells from immunized donors ex vivo. Specific toxicity was confirmed on an antigen-specific population of human CD27(+) memory B cells. This protein engineering strategy can be used as a generalized platform approach for the construction of therapeutic fusion proteins with disease-relevant antigens as B cell receptor-binding domains, offering a promising approach for the specific depletion of autoreactive B-lymphocytes in B cell-driven autoimmune diseases.

Cyclophilin B protects SH-SY5Y human neuroblastoma cells against MPP(+)-induced neurotoxicity via JNK pathway.

PubMed

Oh, Yoojung; Jeong, Kwon; Kim, Kiyoon; Lee, Young-Seok; Jeong, Suyun; Kim, Sung Soo; Yoon, Kyung-Sik; Ha, Joohun; Kang, Insug; Choe, Wonchae

2016-09-23

Parkinson's disease (PD) is the second most common neurodegenerative disorder of aging. PD involves a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. 1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyidine (MPTP) and its toxic metabolite 1-methyl-4-phenylpyridinium ion (MPP+) inhibit the complex I of the mitochondrial electron transport chain, and have been widely used to construct PD models. Cyclophilin B (CypB) is an endoplasmic reticulum protein that binds to cyclosporine A as a cyclophilin family member. CypB has peptidyl-prolyl cis-trans isomerase (PPIase) activity. We investigated the protective effects of overexpressed CypB on MPP+-induced neurocytotoxicity in SH-SY5Y human neuroblastoma cells. Overexpressed CypB decreased MPP(+)-induced oxidative stress through the modulation of antioxidant enzymes including manganese superoxide dismutase and catalase, and prevented neurocytotoxicity via mitogen-activated protein kinase, especially the c-Jun N-terminal kinase pathway. In addition, CypB inhibited the activation of MPP(+)-induced the pro-apoptotic molecules poly (ADP-ribose) polymerase, Bax, and Bcl-2, and attenuated MPP(+)-induced mitochondrial dysfunction. The data suggest that overexpressed CypB protects neuronal cells from MPP+-induced dopaminergic neuronal cell death. Copyright © 2016 Elsevier Inc. All rights reserved.

Strong and multi-antigen specific immunity by hepatitis B core antigen (HBcAg)-based vaccines in a murine model of chronic hepatitis B: HBcAg is a candidate for a therapeutic vaccine against hepatitis B virus.

PubMed

Akbar, Sheikh Mohammad Fazle; Chen, Shiyi; Al-Mahtab, Mamun; Abe, Masanori; Hiasa, Yoichi; Onji, Morikazu

2012-10-01

Experimental evidence suggests that hepatitis B core antigen (HBcAg)-specific cytotoxic T lymphocytes (CTL) are essential for the control of hepatitis B virus (HBV) replication and prevention of liver damage in patients with chronic hepatitis B (CHB). However, most immune therapeutic approaches in CHB patients have been accomplished with hepatitis B surface antigen (HBsAg)-based prophylactic vaccines with unsatisfactory clinical outcomes. In this study, we prepared HBsAg-pulsed dendritic cells (DC) and HBcAg-pulsed DC by culturing spleen DC from HBV transgenic mice (HBV TM) and evaluated the immunomodulatory capabilities of these antigens, which may serve as a better therapy for CHB. The kinetics of HBsAg, antibody levels against HBsAg (anti-HBs), proliferation of HBsAg- and HBcAg-specific lymphocytes, production of antigen-specific CTL, and activation of endogenous DC were compared between HBV TM vaccinated with either HBsAg- or HBcAg-pulsed DC. Vaccination with HBsAg-pulsed DC induced HBsAg-specific immunity, but failed to induce HBcAg-specific immunity in HBV TM. However, immunization of HBV TM with HBcAg-pulsed DC resulted in: (1) HBsAg negativity, (2) production of anti-HBs, and (3) development of HBsAg- and HBcAg-specific T cells and CTL in the spleen and the liver. Additionally, significantly higher levels of activated endogenous DC were detected in HBV TM immunized with HBcAg-pulsed DC compared to HBsAg-pulsed DC (p<0.05). The capacity of HBcAg to modulate both HBsAg- and HBcAg-specific immunity in HBV TM, and activation of endogenous DC in HBV TM without inducing liver damage suggests that HBcAg should be an integral component of the therapeutic vaccine against CHB. Copyright © 2012 Elsevier B.V. All rights reserved.

Plasma membrane vesicles decorated with glycolipid-anchored antigens and adjuvants via protein transfer as an antigen delivery platform for inhibition of tumor growth.

PubMed

Patel, Jaina M; Vartabedian, Vincent F; Bozeman, Erica N; Caoyonan, Brianne E; Srivatsan, Sanjay; Pack, Christopher D; Dey, Paulami; D'Souza, Martin J; Yang, Lily; Selvaraj, Periasamy

2016-01-01

Antigen delivered within particulate materials leads to enhanced antigen-specific immunity compared to soluble administration of antigen. However, current delivery approaches for antigen encapsulated in synthetic particulate materials are limited by the complexity of particle production that affects stability and immunogenicity of the antigen. Herein, we describe a protein delivery system that utilizes plasma membrane vesicles (PMVs) derived from biological materials such as cultured cells or isolated tissues and a simple protein transfer technology. We show that these particulate PMVs can be easily modified within 4 h by a protein transfer process to stably incorporate a glycosylphosphatidylinositol (GPI)-anchored form of the breast cancer antigen HER-2 onto the PMV surface. Immunization of mice with GPI-HER-2-modified-PMVs induced strong HER-2-specific antibody responses and protection from tumor challenge in two different breast cancer models. Further incorporation of the immunostimulatory molecules IL-12 and B7-1 onto the PMVs by protein transfer enhanced tumor protection and induced beneficial Th1 and Th2-type HER-2-specific immune responses. Since protein antigens can be easily converted to GPI-anchored forms, these results demonstrate that isolated plasma membrane vesicles can be modified with desired antigens along with immunostimulatory molecules by protein transfer and used as a vaccine delivery vehicle to elicit potent antigen-specific immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating the protective efficacy of antigen combinations against Photobacterium damselae ssp. piscicida infections in cobia, Rachycentron canadum L.

PubMed

Ho, L-P; Chang, C-J; Liu, H-C; Yang, H-L; Lin, J H-Y

2014-01-01

Cobia, Rachycentron canadum L., is a very important aquatic fish that faces the risk of infection with the bacterial pathogen Photobacterium damselae ssp. piscicida, and there are few protective approaches available that use multiple antigens. In the present study, potent bivalent antigens from P. damselae ssp. piscicida showed more efficient protection than did single antigens used in isolation. In preparations of three antigens that included recombinant heat shock protein 60 (rHSP60), recombinant α-enolase (rENOLASE) and recombinant glyceraldehyde-3-phosphate dehydrogenase (rGAPDH), we analysed the doses that elicited the best immune responses and found that this occurred at a total of 30 μg of antigen per fish. Subsequently, vaccination of fish with rHSP60, rENOLASE and rGAPDH achieved 46.9, 52 and 25% relative per cent survival (RPS), respectively. In addition, bivalent subunit vaccines--combination I (rHSP60 + rENOLASE), combination II (rENOLASE + rGAPDH) and combination III (rHSP60 + rGAPDH)--were administered and the RPS in these groups (65.6, 64.0 and 48.4%, respectively), was higher than that achieved with single-antigen administration. Finally, in combination IV, the trivalent vaccine rHSP60 + rENOLASE + rGAPDH, the RPS was 1.6%. Taken together, our results suggest that combinations of two antigens may achieve a better efficiency than monovalent or trivalent antigens, and this may provide new insights into pathogen prevention strategies. © 2013 John Wiley & Sons Ltd.

Original antigenic sin responses to influenza viruses.

PubMed

Kim, Jin Hyang; Skountzou, Ioanna; Compans, Richard; Jacob, Joshy

2009-09-01

Most immune responses follow Burnet's rule in that Ag recruits specific lymphocytes from a large repertoire and induces them to proliferate and differentiate into effector cells. However, the phenomenon of "original antigenic sin" stands out as a paradox to Burnet's rule of B cell engagement. Humans, upon infection with a novel influenza strain, produce Abs against older viral strains at the expense of responses to novel, protective antigenic determinants. This exacerbates the severity of the current infection. This blind spot of the immune system and the redirection of responses to the "original Ag" rather than to novel epitopes were described fifty years ago. Recent reports have questioned the existence of this phenomenon. Hence, we revisited this issue to determine the extent to which original antigenic sin is induced by variant influenza viruses. Using two related strains of influenza A virus, we show that original antigenic sin leads to a significant decrease in development of protective immunity and recall responses to the second virus. In addition, we show that sequential infection of mice with two live influenza virus strains leads to almost exclusive Ab responses to the first viral strain, suggesting that original antigenic sin could be a potential strategy by which variant influenza viruses subvert the immune system.

Protection against Escherichia coli K1 infection in newborn rats by antibody to K1 capsular polysaccharide antigen.

PubMed

Bortolussi, R; Ferrier, P

1980-04-01

The protective value of antibody to the K1 capsular polysaccharide antigen of Escherichia coli was investigated in a newborn rat model of E. coli K1 infection. Pregnant rats were immunized intravenously with E. coli, and the agglutinating titer to meningococcal group B polysaccharide, which is identical to K1 polysaccharide, was measured in the serum of rats and their offspring. Convalescent serum from rat mothers showed an increased antibody titer in animals injected twice but not once with E. coli K1. Although no agglutinating antibody was detected in the serum of rat pups, animals suckled by mothers having a meningococcal group B agglutinating titer of 1:8 or greater had reduced infection and mortality rates after intraperitoneal injection with E. coli K1 compared with animals suckled by mothers having a low titer of agglutinating antibody (P less than 0.05). In addition, greater protection could be conferred on rat sucklings by oral supplementation with a horse serum rich in antibody to meningococcal group B polysaccharide, suggesting that antibody was abosorbed from the gastrointestinal tract and by itself could be protective. These studies demonstrated that antibody to the capsular polysaccharide of E. coli K1 altered the severity of E. coli K1 infection. Final clearance of bacteria from the blood appeared to await the maturation of other host defense systems in the newborn rat.

B Cell Antigen Receptor Signaling and Internalization Are Mutually Exclusive Events

PubMed Central

Hou, Ping; Araujo, Elizabeth; Zhao, Tong; Zhang, Miao; Massenburg, Don; Veselits, Margaret; Doyle, Colleen; Dinner, Aaron R; Clark, Marcus R

2006-01-01

Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands. PMID:16719564

First finding of genetic and antigenic diversity in 1b-BVDV isolates from Argentina.

PubMed

Pecora, A; Malacari, D A; Ridpath, J F; Perez Aguirreburualde, M S; Combessies, G; Odeón, A C; Romera, S A; Golemba, M D; Wigdorovitz, A

2014-02-01

Infection with Bovine Viral Diarrhea Viruses (BVDV) in cattle results in a wide range of clinical manifestations, ranging from mild respiratory disease to fetal death and mucosal disease, depending on the virulence of the virus and the immune and reproductive status of the host. In this study 30 Argentinean BVDV isolates were characterized by phylogenetic analysis. The isolates were genotyped based on comparison of the 5' untranslated region (5' UTR) and the E2 gene. In both phylogenetic trees, 76% of the viruses were assigned to BVDV 1b, whereas BVDV 1a, 2a and 2b were also found. Eight of the BVDV 1b isolates were further characterized by cross-neutralization tests using guinea pig antisera and sera from bovines vaccinated with two different commercial vaccines. The results demonstrated the presence of a marked antigenic diversity among Argentinean BVDV isolates and suggest the need to incorporate BVDV 1b isolates in diagnostic strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

A genetically adjuvanted influenza B virus vector increases immunogenicity and protective efficacy in mice.

PubMed

Kittel, Christian; Wressnigg, Nina; Shurygina, Anna Polina; Wolschek, Markus; Stukova, Marina; Romanovskaya-Romanko, Ekatherina; Romanova, Julia; Kiselev, Oleg; Muster, Thomas; Egorov, Andrej

2015-10-01

The existence of multiple antigenically distinct types and subtypes of influenza viruses allows the construction of a multivalent vector system for the mucosal delivery of foreign sequences. Influenza A viruses have been exploited successfully for the expression of extraneous antigens as well as immunostimulatory molecules. In this study, we describe the development of an influenza B virus vector whose functional part of the interferon antagonist NS1 was replaced by human interleukin 2 (IL2) as a genetic adjuvant. We demonstrate that IL2 expressed by this viral vector displays immune adjuvant activity in immunized mice. Animals vaccinated with the IL2 viral vector showed an increased hemagglutination inhibition antibody response and higher protective efficacy after challenge with a wild-type influenza B virus when compared to mice vaccinated with a control virus. Our results demonstrate that it is feasible to construct influenza B vaccine strains expressing immune-potentiating foreign sequences from the NS genomic segment. Based on these data, it is now hypothetically possible to create a trivalent (or quadrivalent) live attenuated influenza vaccine in which each component expresses a selected genetic adjuvant with tailored expression levels.

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.

Evaluation of immunogenicity and protective efficacy of orally delivered Shigella type III secretion system proteins IpaB and IpaD

PubMed Central

Heine, Shannon J.; Diaz-McNair, Jovita; Martinez-Becerra, Francisco J.; Choudhari, Shyamal P.; Clements, John D.; Picking, Wendy L.; Pasetti, Marcela F.

2013-01-01

Shigella spp. are food- and water-borne pathogens that cause shigellosis, a severe diarrheal and dysenteric disease that is associated with a high morbidity and mortality in resource-poor countries. No licensed vaccine is available to prevent shigellosis. We have recently demonstrated that Shigella invasion plasmid antigens (Ipas), IpaB and IpaD, which are components of the bacterial type III secretion system (TTSS), can prevent infection in a mouse model of intranasal immunization and lethal pulmonary challenge. Because they are conserved across Shigella spp. and highly immunogenic, these proteins are excellent candidates for a cross-protective vaccine. Ideally, such a vaccine could be administered to humans orally to induce mucosal and systemic immunity. In this study, we investigated the immunogenicity and protective efficacy of Shigella IpaB and IpaD administered orally with a double mutant of the Escherichia coli heat labile toxin (dmLT) as a mucosal adjuvant. We characterized the immune responses induced by oral vs. intranasal immunization and the protective efficacy using a mouse pulmonary infection model. Serum IgG and fecal IgA against IpaB were induced after oral immunization. These responses, however, were lower than those obtained after intranasal immunization despite a 100-fold dosage increase. The level of protection induced by oral immunization with IpaB and IpaD was 40%, while intranasal immunization resulted in 90% protective efficacy. IpaB- and IpaD-specific IgA antibody-secreting cells in the lungs and spleen and T-cell-derived IL-2, IL-5, IL-17 and IL-10 were associated with protection. These results demonstrate the immunogenicity of orally administered IpaB and IpaD and support further studies in humans. PMID:23644075

Antigenic analyses of tissues and excretory and secretory products from Strongylus vulgaris.

PubMed Central

Wynne, E; Slocombe, J O; Wilkie, B N

1981-01-01

Rabbit antisera were prepared against veronal buffered saline extracts of L4 and L5 Strongylus vulgaris, adult S. vulgaris and adult Strongylus equinus retrieved from naturally infected horses. In agar gel diffusion with these antisera, adult S vulgaris and S. equinus each appeared to have at least one unique antigen; larval S. vulgaris appeared to have two species-specific and two stage-specific antigens. There were several common antigens. Excretory and secretory products were collected also from L4 and L5 an maintained over several days in tissue culture fluid. In agar gel diffusion against the above rabbit antisera, a stage-specific antigen was found also in excretory and secretory products. In addition, excretory and secretory products had three antigens in common with adult and larval S. vulgaris, but only one of these was common to adult S. equinus. The excretory and secretory products appear, therefore, to have two species-specific and one stage-specific antigens. Images Fig. 1 a and b. Fig. 2 a and b. Fig. 3 a and b. Fig. 4 a and b. Fig. 5 a and b. Fig. 6 a and b. Fig. 7 a and b. Fig. 8 a and b. PMID:6804070

A DNA Vaccine That Targets Hemagglutinin to Antigen-Presenting Cells Protects Mice against H7 Influenza

PubMed Central

Andersen, Tor Kristian; Zhou, Fan; Cox, Rebecca; Bogen, Bjarne

2017-01-01

ABSTRACT Zoonotic influenza H7 viral infections have a case fatality rate of about 40%. Currently, no or limited human to human spread has occurred, but we may be facing a severe pandemic threat if the virus acquires the ability to transmit between humans. Novel vaccines that can be rapidly produced for global distribution are urgently needed, and DNA vaccines may be the only type of vaccine that allows for the speed necessary to quench an emerging pandemic. Here, we constructed DNA vaccines encoding the hemagglutinin (HA) from influenza A/chicken/Italy/13474/99 (H7N1). In order to increase the efficacy of DNA vaccination, HA was targeted to either major histocompatibility complex class II molecules or chemokine receptors 1, 3, and 5 (CCR1/3/5) that are expressed on antigen-presenting cells (APC). A single DNA vaccination with APC-targeted HA significantly increased antibody levels in sera compared to nontargeted control vaccines. The antibodies were confirmed neutralizing in an H7 pseudotype-based neutralization assay. Furthermore, the APC-targeted vaccines increased the levels of antigen-specific cytotoxic T cells, and a single DNA vaccination could confer protection against a lethal challenge with influenza A/turkey/Italy/3889/1999 (H7N1) in mice. In conclusion, we have developed a vaccine that rapidly could contribute protection against a pandemic threat from avian influenza. IMPORTANCE Highly pathogenic avian influenza H7 constitute a pandemic threat that can cause severe illness and death in infected individuals. Vaccination is the main method of prophylaxis against influenza, but current vaccine strategies fall short in a pandemic situation due to a prolonged production time and insufficient production capabilities. In contrast, a DNA vaccine can be rapidly produced and deployed to prevent the potential escalation of a highly pathogenic influenza pandemic. We here demonstrate that a single DNA delivery of hemagglutinin from an H7 influenza could mediate full

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

Targeting of plant-derived vaccine antigens to immunoresponsive mucosal sites.

PubMed

Rigano, M Manuela; Sala, Francesco; Arntzen, Charles J; Walmsley, Amanda M

2003-01-30

Most pathogenic microorganisms enter their host via the mucosal surfaces lining the digestive, respiratory and urino-reproductive tracts of the body. The most efficient means of protecting these surfaces is through mucosal immunization. Transgenic plants are safe and inexpensive vehicles to produce and mucosally deliver protective antigens. However, the application of this technology is limited by the poor response of the immune system to non-particulate, subunit vaccines. Co-delivery of therapeutic proteins with targeting proteins, such as the B subunit of the Escherichia coli heat labile enterotoxin (LTB), could increase the effectiveness of such antigens.

Fy(a)/Fy(b) antigen polymorphism in human erythrocyte Duffy antigen affects susceptibility to Plasmodium vivax malaria.

PubMed

King, Christopher L; Adams, John H; Xianli, Jia; Grimberg, Brian T; McHenry, Amy M; Greenberg, Lior J; Siddiqui, Asim; Howes, Rosalind E; da Silva-Nunes, Monica; Ferreira, Marcelo U; Zimmerman, Peter A

2011-12-13

Plasmodium vivax (Pv) is a major cause of human malaria and is increasing in public health importance compared with falciparum malaria. Pv is unique among human malarias in that invasion of erythrocytes is almost solely dependent on the red cell's surface receptor, known as the Duffy blood-group antigen (Fy). Fy is an important minor blood-group antigen that has two immunologically distinct alleles, referred to as Fy(a) or Fy(b), resulting from a single-point mutation. This mutation occurs within the binding domain of the parasite's red cell invasion ligand. Whether this polymorphism affects susceptibility to clinical vivax malaria is unknown. Here we show that Fy(a), compared with Fy(b), significantly diminishes binding of Pv Duffy binding protein (PvDBP) at the erythrocyte surface, and is associated with a reduced risk of clinical Pv in humans. Erythrocytes expressing Fy(a) had 41-50% lower binding compared with Fy(b) cells and showed an increased ability of naturally occurring or artificially induced antibodies to block binding of PvDBP to their surface. Individuals with the Fy(a+b-) phenotype demonstrated a 30-80% reduced risk of clinical vivax, but not falciparum malaria in a prospective cohort study in the Brazilian Amazon. The Fy(a+b-) phenotype, predominant in Southeast Asian and many American populations, would confer a selective advantage against vivax malaria. Our results also suggest that efficacy of a PvDBP-based vaccine may differ among populations with different Fy phenotypes.

Improved detection of acute parvovirus B19 infection by immunoglobulin M EIA in combination with a novel antigen EIA.

PubMed

Corcoran, A; Kerr, S; Elliott, G; Koppelman, M; Doyle, S

2007-10-01

Although parvovirus B19 is a significant blood product contaminant, few methods other than polymerase chain reaction (PCR) have been developed to detect the presence of the virus. A B19 antigen enzyme immunoassay (EIA) has been developed and the sensitivity of detection is ascertained using dilutions of the B19 capsid protein VP2 and 10-fold dilutions of B19 viraemic serum. Once the assay cut-off was established, a panel of viraemic donations (n = 70) was screened by the antigen EIA. The B19 immunoglobulin M (IgM) and IgG status of these specimens was also determined. During screening of blood donor units by quantitative PCR, 70 individuals were identified with levels of B19 DNA greater than 10(6) IU/ml at the time of blood donation. The sensitivity of the B19 antigen EIA was estimated to be equivalent to between 10(8) and 10(9) IU/ml B19 DNA or 1-10 pg/ml of recombinant capsid protein. B19 detection was significantly enhanced when viraemic specimens were pretreated with a low pH proprietary reagent. Unlike other virus-detection assays, detection of the B19 antigen was not affected by the presence of B19 IgM or IgG antibodies. In addition, the assay was capable of detecting all three genotypes of human erythrovirus. Combined specimen analysis by the B19 antigen assay and a B19 IgM assay facilitated the detection of 91% of acute B19 infections in the test population. In combination with B19 IgM detection, application of the B19 antigen EIA is a flexible and efficient method of detecting recent B19 infection and can be used as an alternative to PCR.

Characterization of monoclonal antibodies against hepatitis C virus nonstructural protein 3: different antigenic determinants from human B cells.

PubMed

Ou-Yang, P; Chiang, B L; Hwang, L H; Chen, Y G; Yang, P M; Chi, W K; Chen, P J; Chen, D S

1999-04-01

The nonstructural (NS3) region protein of hepatitis C virus (HCV) possesses major B-cell epitopes that induce antibodies after infection. To elucidate further the characteristics of these B cells and their role in the immune regulation of HCV infection, T9 (portion of NS3 region, amino acids [a.a.] 1188-1493)-specific monoclonal antibodies were derived and mapped for B-cell antigenic determinants with recombinant proteins. A total of 10 T9-specific hybridomas were generated and tested for B-cell antigenic determinants. To analyze the B-cell antigenic determinants, eight recombinant proteins including NS3-e (a.a. 1175-1334), NS3-a' (a.a. 1175-1250), NS3-a (a.a. 1251-1334), NS3-b (a.a. 1323-1412), NS3-c (a.a. 1407-1499), NS3-a/b (a.a. 1251-1412), NS3-bc (a.a. 1323-1499), and NS3-abc (a.a. 1251-1499) encoded by NS3-region internal clones were expressed and tested for immunoblotting. The data suggested IgG hybridomas recognized NS3-a, NS3-a', or NS3-b protein by immunoblotting. By contrast, the NS3-e protein bears the major antigenic determinant recognized by human sera. Half of the hybridomas were found to react with protein NS3-a', which is not a major B-cell antigenic determinant in humans. These data suggested that conformational epitopes in vivo may be important for B-cell recognition.

Molecular analysis of antigen-independent adhesion forces between T and B lymphocytes.

PubMed Central

Amblard, F; Auffray, C; Sekaly, R; Fischer, A

1994-01-01

The low-affinity interactions underlying antigen recognition by T-cell receptors (TCRs) are thought to involve antigen-independent adhesion mechanisms. Using a hydrodynamic approach, we found that antigen-independent adhesion occurred between human B cells and resting T cells in a transient and temperature-dependent fashion. The mean cell-cell adhesion force was 0.32 x 10(-9) N and was generated by similar contributions (0.16 x 10(-9) N) of the LFA-1- and CD2-dependent adhesion pathways. After T-cell stimulation with a phorbol ester, the force contributed by LFA-1 was drastically increased, while that of CD2 was unaffected. We propose that weak receptor-mediated adhesion initiates antigen-independent intercellular contacts required for antigen recognition by the TCR and is upregulated following TCR engagement. The method used permits adhesion forces between living cells to be resolved at the molecular level and should prove valuable for the rapid assessment of interaction forces between various types of cells and cell-sized particles. Images PMID:7909604

Caffeine Eye Drops Protect Against UV-B Cataract

PubMed Central

Kronschläger, Martin; Löfgren, Stefan; Yu, Zhaohua; Talebizadeh, Nooshin; Varma, Shambhu D.; Söderberg, Per

2013-01-01

The purpose of this study was to investigate if topically applied caffeine protects against in vivo ultraviolet radiation cataract and if so, to estimate the protection factor. Three experiments were carried out. First, two groups of Sprague-Dawley rats were pre-treated with a single application of either placebo or caffeine eye drops in both eyes. All animals were then unilaterally exposed in vivo to 8 kJ/m2 UV-B radiation for 15 min. One week later, the lens GSH levels were measured and the degree of cataract was quantified by measurement of in vitro lens light scattering. In the second experiment, placebo and caffeine pre-treated rats were divided in five UV-B radiation dose groups, receiving 0.0, 2.6, 3.7, 4.5 or 5.2 kJ/m2 UV-B radiation in one eye. Lens light scattering was determined after one week. In the third experiment, placebo and caffeine pre-treated rats were UV-B-exposed and the presence of activated caspase-3 was visualized by immunohistochemistry. There was significantly less UV-B radiation cataract in the caffeine group than in the placebo group (95% confidence interval for mean difference in lens light scattering between the groups = 0.10 ± 0.05 tEDC), and the protection factor for caffeine was 1.23. There was no difference in GSH levels between the placebo- and the caffeine group. There was more caspase-3 staining in UV-B-exposed lenses from the placebo group than in UV-B-exposed lenses from the caffeine group. Topically applied caffeine protects against ultraviolet radiation cataract, reducing lens sensitivity 1.23 times. PMID:23644096

Failure to protect calves against Taenia saginata using antigens prepared from in vitro cultivation of the larval stage.

PubMed

Mitchell, G B; Armour, J

1980-11-01

Calves were vaccinated intramuscularly against the tapeworm Taenia saginata using excretory/secretory (ES) antigens from short and long term periods of in vitro cultivation of the larval stage of the parasite, four weeks before challenge with 5000 T saginata onchospheres. Neither immunisation regime employed afforded significant protection against challenge. It was considered that this may have been due to a reduction in concentration of, or detrimental effects to, potential immunogens during vaccine production. Elucidation of the nature of the protective ES antigens necessary for standardization of the technique has yet to be achieved in helminths.

Selection of tumor antigens as targets for immune attack using immunohistochemistry: protein antigens.

PubMed

Zhang, S; Zhang, H S; Cordon-Cardo, C; Ragupathi, G; Livingston, P O

1998-11-01

The relative expression of mucin antigens MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, and MUC7 and glycoprotein antigens KSA, carcinoembryonic antigen, prostate-specific membrane antigen (PSMA), HER-2/neu, and human chorionic gonadotropin-beta on different cancers and normal tissues is difficult to determine from available reports. We have compared the distribution of these antigens by immunohistology on a broad range of malignant and normal tissues. MUC1 expression was most intense in cancers of breast, lung, ovarian, and endometrial origin; MUC2 was most intense in cancers of colon and prostate origin; and MUC5AC was most intense in cancers of breast and gastric origin. MUC4 was intensely expressed in 50% of cancers of colon and pancreas origin, and MUC3, MUC5B, and MUC7 were expressed in a variety of epithelial cancers, but not so intensely. KSA was intensely and uniformly expressed on all epithelial cancers; carcinoembryonic antigen was expressed in most cancers of breast, lung, colon, pancreas, and gastric origin; and PSMA was expressed only in cancers of prostate origin. Human chorionic gonadotropin-beta was expressed on the majority of sarcomas and cancers of breast, lung, and pancreas origin, although intense staining was not seen. Staining on normal tissues was restricted to one or many normal epithelial tissues ranging from MUC3, MUC4, and PSMA, which were expressed only on epithelia of pancreas, stomach, and prostate origin, respectively, to MUC1 and KSA, which were expressed on most normal epithelia. Expression was restricted to the secretory borders of these epithelia while stroma and other normal tissues were completely negative. These results plus the results of the two previous papers (S. Zhang et al, Int. J. Cancer, 73: 42-49, 1997; S. Zhang et al., Int. J. Cancer, 73: 50-56, 1997) in this series provide the basis for selection of multiple cell surface antigens as targets for antibody-mediated attack against these cancers.

Studies on B-cell memory. III. T-dependent aspect of B memory generation in mice immunized with T-independent type-2(TI-2) antigen.

PubMed

Hosokawa, T; Tanaka, Y; Aoike, A; Kawai, K; Muramatsu, S

1984-09-01

The time course of B-cell memory development to a dinitrophenyl (DNP) T-independent type-2 (TI-2) antigen was investigated by adoptive cell transfer. Strong IgM and IgG memory developed in BALB/c mice after immunization with DNP-dextran, to be recalled by challenge with either T-dependent (TD) antigen or TI-2 antigen. However, only weak IgM memory and very feeble IgG memory were detected in athymic nude mice receiving the same immunization as euthymic mice. Once memory was established under probable T cell influence, its recall by TI-2 antigen challenge seemed independent of T cell help and did not require sharing of carriers between priming and challenge antigens. The following may be concluded. (i) Long-term IgM and IgG memory is induced by TI-2 antigen priming in the presence of functional T cells. (ii) The class switch from IgM to IgG in the memory B cell pool is driven effectively by TI-2 antigen and is probably T cell-dependent.

A UV-B-specific signaling component orchestrates plant UV protection

PubMed Central

Brown, Bobby A.; Cloix, Catherine; Jiang, Guang Huai; Kaiserli, Eirini; Herzyk, Pawel; Kliebenstein, Daniel J.; Jenkins, Gareth I.

2005-01-01

UV-B radiation in sunlight has diverse effects on humans, animals, plants, and microorganisms. UV-B can cause damage to molecules and cells, and consequently organisms need to protect against and repair UV damage to survive in sunlight. In plants, low nondamaging levels of UV-B stimulate transcription of genes involved in UV-protective responses. However, remarkably little is known about the underlying mechanisms of UV-B perception and signal transduction. Here we report that Arabidopsis UV RESISTANCE LOCUS 8 (UVR8) is a UV-B-specific signaling component that orchestrates expression of a range of genes with vital UV-protective functions. Moreover, we show that UVR8 regulates expression of the transcription factor HY5 specifically when the plant is exposed to UV-B. We demonstrate that HY5 is a key effector of the UVR8 pathway, and that it is required for survival under UV-B radiation. UVR8 has sequence similarity to the eukaryotic guanine nucleotide exchange factor RCC1, but we found that it has little exchange activity. However, UVR8, like RCC1, is located principally in the nucleus and associates with chromatin via histones. Chromatin immunoprecipitation showed that UVR8 associates with chromatin in the HY5 promoter region, providing a mechanistic basis for its involvement in regulating transcription. We conclude that UVR8 defines a UV-B-specific signaling pathway in plants that orchestrates the protective gene expression responses to UV-B required for plant survival in sunlight. PMID:16330762

Subcomponent vaccine based on CTA1-DD adjuvant with incorporated UreB class II peptides stimulates protective Helicobacter pylori immunity.

PubMed

Nedrud, John G; Bagheri, Nayer; Schön, Karin; Xin, Wei; Bergroth, Hilda; Eliasson, Dubravka Grdic; Lycke, Nils Y

2013-01-01

A mucosal vaccine against Helicobacter pylori infection could help prevent gastric cancers and peptic ulcers. While previous attempts to develop such a vaccine have largely failed because of the requirement for safe and effective adjuvants or large amounts of well defined antigens, we have taken a unique approach to combining our strong mucosal CTA1-DD adjuvant with selected peptides from urease B (UreB). The protective efficacy of the selected peptides together with cholera toxin (CT) was first confirmed. However, CT is a strong adjuvant that unfortunately is precluded from clinical use because of its toxicity. To circumvent this problem we have developed a derivative of CT, the CTA1-DD adjuvant, that has been found safe in non-human primates and equally effective compared to CT when used intranasally. We genetically fused the selected peptides into the CTA1-DD plasmid and found after intranasal immunizations of Balb/c mice using purified CTA1-DD with 3 copies of an H. pylori urease T cell epitope (CTA1-UreB3T-DD) that significant protection was stimulated against a live challenge infection. Protection was, however, weaker than with the gold standard, bacterial lysate+CT, but considering that we only used a single epitope in nanomolar amounts the results convey optimism. Protection was associated with enhanced Th1 and Th17 immunity, but immunizations in IL-17A-deficient mice revealed that IL-17 may not be essential for protection. Taken together, we have provided evidence for the rational design of an effective mucosal subcomponent vaccine against H. pylori infection based on well selected protective epitopes from relevant antigens incorporated into the CTA1-DD adjuvant platform.

Intranasal immunization with protective antigen of Bacillus anthracis induces a long-term immunological memory response.

PubMed

Woo, Sun-Je; Kang, Seok-Seong; Park, Sung-Moo; Yang, Jae Seung; Song, Man Ki; Yun, Cheol-Heui; Han, Seung Hyun

2015-10-01

Although intranasal vaccination has been shown to be effective for the protection against inhalational anthrax, establishment of long-term immunity has yet to be achieved. Here, we investigated whether intranasal immunization with recombinant protective antigen (rPA) of Bacillus anthracis induces immunological memory responses in the mucosal and systemic compartments. Intranasal immunization with rPA plus cholera toxin (CT) sustained PA-specific antibody responses for 6 months in lung, nasal washes, and vaginal washes as well as serum. A significant induction of PA-specific memory B cells was observed in spleen, cervical lymph nodes (CLNs) and lung after booster immunization. Furthermore, intranasal immunization with rPA plus CT remarkably generated effector memory CD4(+) T cells in the lung. PA-specific CD4(+) T cells preferentially increased the expression of Th1- and Th17-type cytokines in lung, but not in spleen or CLNs. Collectively, the intranasal immunization with rPA plus CT promoted immunologic memory responses in the mucosal and systemic compartments, providing long-term immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cross-Reactivity between Schistosoma mansoni Antigens and the Latex Allergen Hev b 7: Putative Implication of Cross-Reactive Carbohydrate Determinants (CCDs)

PubMed Central

Doenhoff, Michael J.; El-Faham, Marwa; Liddell, Susan; Fuller, Heidi R.; Stanley, Ronald G.; Schramm, Gabriele; Igetei, Joseph E.

2016-01-01

IgG antibodies produced by rabbits immunized against S. mansoni antigens cross-reacted with aqueous soluble constituents of a variety of allergens. The antibody cross-reactivity was largely sensitive to degradation by treatment of the target antigens with sodium meta-periodate, suggesting the cross-reactivity was due to carbohydrate determinants that were common to both the schistosome and the allergens (CCDs). The reaction between the rabbit antibodies and a 43 kDa molecule in a rubber latex extract was analysed further: tandem mass spectrometry identified the latex molecule as allergen Hev b 7. Rabbit anti-schistosome IgG antibodies purified by acid-elution from solid-phase latex Hev b 7 reacted with the S. mansoni egg antigens IPSE/alpha-1 and kappa-5 and cercarial antigens SPO-1 and a fatty acid-binding protein. Moreover, purified anti-S. mansoni egg, latex cross-reactive antibodies reacted with antigenic constituents of some fruits, a result of potential relevance to the latex-fruit syndrome of allergic reactions. We propose that IgG anti-schistosome antibodies that cross-react with allergens may be able to block IgE-induced allergic reactions and thus provide a possible explanation for the hygiene hypothesis. PMID:27467385

EBOV Protection Is Supported by T Cell-Dependent Humoral Responses But Is Not Requisite for Survival

DTIC Science & Technology

2016-06-03

EBOV protection is supported by T cell- dependent humoral responses but is not requisite for survival. 1 Christopher L. Cooper, Karen A. Martins...platforms of a requisite role for antibody-5 dependent protection and extensive efforts in development of antibody therapy against lethal EBOV 6... dependent 12 mechanisms. We show that Hiltonol both augmented and sustained eVLP-mediated GC B cell formation 13 and increased antigen-specific B cell

Poly-ϵ-caprolactone/chitosan nanoparticles provide strong adjuvant effect for hepatitis B antigen.

PubMed

Jesus, Sandra; Soares, Edna; Borchard, Gerrit; Borges, Olga

2017-10-01

This work aims to investigate the adjuvant effect of poly-ϵ-caprolactone/chitosan nanoparticles (NPs) for hepatitis B surface antigen (HBsAg) and the plasmid DNA encoding HBsAg (pRC/CMV-HBs). Both antigens were adsorbed onto preformed NPs. Vaccination studies were performed in C57BL/6 mice. Transfection efficiency was investigated in A549 cell line. HBsAg-adsorbed NPs generated strong anti-HBsAg IgG titers, mainly of IgG1 isotype, and induced antigen-specific IFN-γ and IL-17 secretion by spleen cells. The addition of pRC/CMV-HBs to the HBsAg-adsorbed NPs inhibited IL-17 secretion but had minor effect on IFN-γ levels. Lastly, pRC/CMV-HBs-loaded NPs generated a weak serum antibody response. Poly-ϵ-caprolactone/chitosan NPs provide a strong humoral adjuvant effect for HBsAg and induce a Th1/Th17-mediated cellular immune responses worth explore for hepatitis B virus vaccination.

Generation and Characterization of Human Monoclonal Antibodies Targeting Anthrax Protective Antigen following Vaccination with a Recombinant Protective Antigen Vaccine.

PubMed

Chi, Xiangyang; Li, Jianmin; Liu, Weicen; Wang, Xiaolin; Yin, Kexin; Liu, Ju; Zai, Xiaodong; Li, Liangliang; Song, Xiaohong; Zhang, Jun; Zhang, Xiaopeng; Yin, Ying; Fu, Ling; Xu, Junjie; Yu, Changming; Chen, Wei

2015-05-01

The anthrax protective antigen (PA) is the central component of the three-part anthrax toxin, and it is the primary immunogenic component in the approved AVA anthrax vaccine and the "next-generation" recombinant PA (rPA) anthrax vaccines. Animal models have indicated that PA-specific antibodies (AB) are sufficient to protect against infection with Bacillus anthracis. In this study, we investigated the PA domain specificity, affinity, mechanisms of neutralization, and synergistic effects of PA-specific antibodies from a single donor following vaccination with the rPA vaccine. Antibody-secreting cells were isolated 7 days after the donor received a boost vaccination, and 34 fully human monoclonal antibodies (hMAb) were identified. Clones 8H6, 4A3, and 22F1 were able to neutralize lethal toxin (LeTx) both in vitro and in vivo. Clone 8H6 neutralized LeTx by preventing furin cleavage of PA in a dose-dependent manner. Clone 4A3 enhanced degradation of nicked PA, thereby interfering with PA oligomerization. The mechanism of 22F1 is still unclear. A fourth clone, 2A6, that was protective only in vitro was found to be neutralizing in vivo in combination with a toxin-enhancing antibody, 8A7, which binds to domain 3 of PA and PA oligomers. These results provide novel insights into the antibody response elicited by the rPA vaccine and may be useful for PA-based vaccine and immunotherapeutic cocktail design. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Production of immunologically active surface antigens of hepatitis B virus by Escherichia coli.

PubMed Central

MacKay, P; Pasek, M; Magazin, M; Kovacic, R T; Allet, B; Stahl, S; Gilbert, W; Schaller, H; Bruce, S A; Murray, K

1981-01-01

Several plasmids have been constructed which direct the synthesis of hepatitis B virus surface antigens in Escherichia coli either as the native polypeptide or fused to other plasmid encoded polypeptides. When injected into rabbits, extracts from bacteria carrying some of these plasmids induced the synthesis of antibodies to the antigens even though the extracts did not give satisfactory positive results in radioimmunoassay for them. Either the NH2-terminal segment or the COOH-terminal segment of the surface antigens alone was sufficient to elicit the immune response, but antibodies against the two segments showed different specificities. The results emphasize the value of an in vivo assay for the presence of antigens in crude cell extracts and illustrate the feasibility of this type of screening with laboratory animals. PMID:6170067

Adoptive immunotherapy for B-cell malignancies with autologous chimeric antigen receptor modified tumor targeted T cells.

PubMed

Park, Jae H; Brentjens, Renier J

2010-04-01

Chemotherapy-resistant B-cell hematologic malignancies may be cured with allogeneic hematopoietic stem cell transplantation (HSCT), demonstrating the potential susceptibility of these tumors to donor T-cell mediated immune responses. However, high rates of transplant-related morbidity and mortality limit this approach. For this reason, there is an urgent need for less-toxic forms of immune-based cellular therapy to treat these malignancies. Adoptive transfer of autologous T cells genetically modified to express chimeric antigen receptors (CARs) targeted to specific tumor-associated antigens represents an attractive means of overcoming the limitations of conventional HSCT. To this end, investigators have generated CARs targeted to various antigens expressed by B-cell malignancies, optimized the design of these CARs to enhance receptor mediated T cell signaling, and demonstrated significant anti-tumor efficacy of the resulting CAR modified T cells both in vitro and in vivo mouse tumor models. These encouraging preclinical data have justified the translation of this approach to the clinical setting with currently 12 open clinical trials and one completed clinical trial treating various B-cell malignancies utilizing CAR modified T cells targeted to either the CD19 or CD20 B-cell specific antigens.

Felix Hoppe-Seyler Lecture 1997. Protective antibody responses against viruses.

PubMed

Zinkernagel, R M

1997-08-01

Neutralizing antibody responses against the acute cytopathic vesicular stomatitis virus (VSV) have been studied in mice to evaluate their general characteristics including specificity, self-/non-self discrimination and memory. IgM responses are generated very early, by day 3 to 4, in a T helper cell-independent fashion and without VSV having polyclonal activating capacities. The order of the glycoprotein tips on the virus envelope (multiple, 8-10 nm distance, paracrystalline) exhibiting the neutralizing determinants are key to this prompt response. These paracrystalline identical multimeric antigens are characteristic of infectious agents and are always reacted against by B cells. Self-antigens that are accessible to B cells in the intact host are either monomeric in serum or mobile multimers on cell surfaces; these configurations need contact dependent or contact independent T help, respectively. Because T help is tolerant against self-antigens, no anti-self B cell responses are usually induced against monomeric self-antigens. If collagen or DNA (rigid multimeric self-antigens) become accessible, however, they may become targets of auto-antibody responses. The antibody repertoire against VSV is partially contained in the germline and partially is generated by somatic mutation; they seem not to undergo affinity-maturation. In any case protection against lethal infection is dependent upon strictly T helper cell dependent IgG generated by day 6 to 7 and reaches a protective level of about 1-10 micrograms/ml. Interesting affinity/avidity and onrate above a minimal threshold are of no apparent advantage for protection in vivo. Maintenance of these antibody levels by antigen depots, and not the presence of memory B cells alone, is key to providing protective immunological memory. Collectively these data suggest that studying biologically important protective antibody responses may modify some of the parameters that have been defined by studying hapten specific antibody

Protective Human Leucocyte Antigen Haplotype, HLA-DRB1*01-B*14, against Chronic Chagas Disease in Bolivia

PubMed Central

del Puerto, Florencia; Nishizawa, Juan Eiki; Kikuchi, Mihoko; Roca, Yelin; Avilas, Cinthia; Gianella, Alberto; Lora, Javier; Velarde, Freddy Udalrico Gutierrez; Miura, Sachio; Komiya, Norihiro; Maemura, Koji; Hirayama, Kenji

2012-01-01

Background Chagas disease, caused by the flagellate parasite Trypanosoma cruzi affects 8–10 million people in Latin America. The mechanisms that underlie the development of complications of chronic Chagas disease, characterized primarily by pathology of the heart and digestive system, are not currently understood. To identify possible host genetic factors that may influence the clinical course of Chagas disease, Human Leucocyte Antigen (HLA) regional gene polymorphism was analyzed in patients presenting with differing clinical symptoms. Methodology Two hundred and twenty nine chronic Chagas disease patients in Santa Cruz, Bolivia, were examined by serological tests, electrocardiogram (ECG), and Barium enema colon X-ray. 31.4% of the examinees showed ECG alterations, 15.7% megacolon and 58.1% showed neither of them. A further 62 seropositive megacolon patients who had undergone colonectomy due to acute abdomen were recruited. We analyzed their HLA genetic polymorphisms (HLA-A, HLA-B, MICA, MICB, DRB1 and TNF-alpha promoter region) mainly through Sequence based and LABType SSO typing test using LUMINEX Technology. Principal Findings The frequencies of HLA-DRB1*01 and HLA-B*14:02 were significantly lower in patients suffering from megacolon as well as in those with ECG alteration and/or megacolon compared with a group of patients with indeterminate symptoms. The DRB1*0102, B*1402 and MICA*011 alleles were in strong Linkage Disequilibrium (LD), and the HLA-DRB1*01-B*14-MICA*011haplotype was associated with resistance against chronic Chagas disease. Conclusions This is the first report of HLA haplotype association with resistance to chronic Chagas disease. PMID:22448298

A novel hemagglutinin protein produced in bacteria protects chickens against H5N1 highly pathogenic avian influenza viruses by inducing H5 subtype-specific neutralizing antibodies

PubMed Central

Sączyńska, Violetta; Romanik, Agnieszka; Florys, Katarzyna; Cecuda-Adamczewska, Violetta; Kęsik-Brodacka, Małgorzata; Śmietanka, Krzysztof; Olszewska, Monika; Domańska-Blicharz, Katarzyna; Minta, Zenon; Szewczyk, Bogusław; Płucienniczak, Grażyna; Płucienniczak, Andrzej

2017-01-01

The highly pathogenic (HP) H5N1 avian influenza viruses (AIVs) cause a mortality rate of up to 100% in infected chickens and pose a permanent pandemic threat. Attempts to obtain effective vaccines against H5N1 HPAIVs have focused on hemagglutinin (HA), an immunodominant viral antigen capable of eliciting neutralizing antibodies. The vast majority of vaccine projects have been performed using eukaryotic expression systems. In contrast, we used a bacterial expression system to produce vaccine HA protein (bacterial HA) according to our own design. The HA protein with the sequence of the H5N1 HPAIV strain was efficiently expressed in Escherichia coli, recovered in the form of inclusion bodies and refolded by dilution between two chromatographic purification steps. Antigenicity studies showed that the resulting antigen, referred to as rH5-E. coli, preserves conformational epitopes targeted by antibodies specific for H5-subtype HAs, inhibiting hemagglutination and/or neutralizing influenza viruses in vitro. The proper conformation of this protein and its ability to form functional oligomers were confirmed by a hemagglutination test. Consistent with the biochemical characteristics, prime-boost immunizations with adjuvanted rH5-E. coli protected 100% and 70% of specific pathogen-free, layer-type chickens against challenge with homologous and heterologous H5N1 HPAIVs, respectively. The observed protection was related to the positivity in the FluAC H5 test (IDVet) but not to hemagglutination-inhibiting antibody titers. Due to full protection, the effective contact transmission of the homologous challenge virus did not occur. Survivors from both challenges did not or only transiently shed the viruses, as established by viral RNA detection in oropharyngeal and cloacal swabs. Our results demonstrate that vaccination with rH5-E. coli could confer control of H5N1 HPAIV infection and transmission rates in chicken flocks, accompanied by reduced virus shedding. Moreover, the role of

Association of human leukocyte A, B, and DR antigens in Colombian patients with diagnosis of spondyloarthritis.

PubMed

Santos, Ana M; Peña, Paola; Avila, Mabel; Briceño, Ignacio; Jaramillo, Carlos; Vargas-Alarcon, Gilberto; Rueda, Juan C; Saldarriaga, Eugenia-Lucia; Angarita, Jose-Ignacio; Martinez-Rodriguez, Nancy; Londono, John

2017-04-01

There is substantial evidence that non-B27 major histocompatibility complex (MHC) genes are associated with spondyloarthritis (SpA). Studies in Mexican and Tunisian populations demonstrated the association of SpA and human leukocyte antigen (HLA) B15. The purpose of this study was to evaluate the association of HLA-A, B, and DR antigens in a group of Colombian patients with a diagnosis of SpA. A total of 189 patients and 100 healthy subjects were included in the present study. All subjects underwent a complete characterization of HLA alleles A, B, and DR. Of the 189 studied patients, 35 were reactive arthritis (ReA), 87 were ankylosing spondylitis (AS), and 67 undifferentiated SpA (uSpA). According to the Assessment of Spondyloarthritis International Society (ASAS) criteria, 167 were axial SpA (axSpA) and 171 were peripheral SpA (pSpA). 63.8% were men, with a mean age of 35.9 ± 12.7 years. 40.7% (77/189) of patients were HLA-B27 positive of which 52.9% had AS and 42.5% axSpA. 23.2% (44/189) of patients were HLA-B15 positive: 23.8% were uSpA, 12.57% were axSpA, and 11.7% were pSpA. In addition, HLA-DRB1*01 was associated with AS (58.6%) and axSpA (42.5%). Also, HLA-DRB1*04 was present in 62 patients with AS (71.2%) and in 26 with axSpA (15.5%). In this population, we found a strong association between the presence of HLA-B27 and the diagnosis of axSpA and AS, but the HLA-B15 is also significantly associated with all subtypes of the disease, predominantly with pSpA. Additionally, HLA-DR1 and DR4 were associated in a cohort of patients with SpA from Colombia.

Characterization and storage of malaria antigens: Localization and chemical characterization of Plasmodium knowlesi schizont antigens

PubMed Central

Deans, J. A.; Cohen, S.

1979-01-01

The identification of malarial antigens that induce protective immunity could provide a rational basis for developing an effective antimalarial vaccine as well as specific serodiagnostic tests indicative of clinical immune status. Since protective immunity is probably induced by stage-dependent rather than stage-independent antigens, the antigenic composition of different stages of Plasmodium knowlesi has been compared, and a limited chemical characterization undertaken. This information should provide some insight into the types of preparative procedure appropriate for the purification of functionally important malarial antigens. PMID:120777

Intranasal H5N1 vaccines, adjuvanted with chitosan derivatives, protect ferrets against highly pathogenic influenza intranasal and intratracheal challenge.

PubMed

Mann, Alex J; Noulin, Nicolas; Catchpole, Andrew; Stittelaar, Koert J; de Waal, Leon; Veldhuis Kroeze, Edwin J B; Hinchcliffe, Michael; Smith, Alan; Montomoli, Emanuele; Piccirella, Simona; Osterhaus, Albert D M E; Knight, Alastair; Oxford, John S; Lapini, Giulia; Cox, Rebecca; Lambkin-Williams, Rob

2014-01-01

We investigated the protective efficacy of two intranasal chitosan (CSN and TM-CSN) adjuvanted H5N1 Influenza vaccines against highly pathogenic avian Influenza (HPAI) intratracheal and intranasal challenge in a ferret model. Six groups of 6 ferrets were intranasally vaccinated twice, 21 days apart, with either placebo, antigen alone, CSN adjuvanted antigen, or TM-CSN adjuvanted antigen. Homologous and intra-subtypic antibody cross-reacting responses were assessed. Ferrets were inoculated intratracheally (all treatments) or intranasally (CSN adjuvanted and placebo treatments only) with clade 1 HPAI A/Vietnam/1194/2004 (H5N1) virus 28 days after the second vaccination and subsequently monitored for morbidity and mortality outcomes. Clinical signs were assessed and nasal as well as throat swabs were taken daily for virology. Samples of lung tissue, nasal turbinates, brain, and olfactory bulb were analysed for the presence of virus and examined for histolopathological findings. In contrast to animals vaccinated with antigen alone, the CSN and TM-CSN adjuvanted vaccines induced high levels of antibodies, protected ferrets from death, reduced viral replication and abrogated disease after intratracheal challenge, and in the case of CSN after intranasal challenge. In particular, the TM-CSN adjuvanted vaccine was highly effective at eliciting protective immunity from intratracheal challenge; serologically, protective titres were demonstrable after one vaccination. The 2-dose schedule with TM-CSN vaccine also induced cross-reactive antibodies to clade 2.1 and 2.2 H5N1 viruses. Furthermore ferrets immunised with TM-CSN had no detectable virus in the respiratory tract or brain, whereas there were signs of virus in the throat and lungs, albeit at significantly reduced levels, in CSN vaccinated animals. This study demonstrated for the first time that CSN and in particular TM-CSN adjuvanted intranasal vaccines have the potential to protect against significant mortality and

Immunoglobulin D (IgD)-deficient mice reveal an auxiliary receptor function for IgD in antigen-mediated recruitment of B cells

PubMed Central

1993-01-01

To assess the role of immunoglobulin D (IgD) in vivo we generated IgD- deficient mice by gene targeting and studied B cell development and function in the absence of IgD expression. In the mutant animals, conventional and CD5-positive (B1) B cells are present in normal numbers, and the expression of the surface markers CD22 and CD23 in the compartment of conventional B cells indicates acquisition of a mature phenotype. As in wild-type animals, most of the peripheral B cells are resting cells. The IgD-deficient mice respond well to T cell- independent and -dependent antigens. However, in heterozygous mutant animals, B cells expressing the wild type IgH locus are overrepresented in the peripheral B cell pool, and T cell-dependent IgG1 responses are further dominated by B cells expressing the wild-type allele. Similarly, in homozygous mutant (IgD-deficient) animals, affinity maturation is delayed in the early primary response compared to control animals, although the mutants are capable of generating high affinity B cell memory. Thus, rather than being involved in major regulatory processes as had been suggested, IgD seems to function as an antigen receptor optimized for efficient recruitment of B cells into antigen- driven responses. The IgD-mediated acceleration of affinity maturation in the early phase of the T cell-dependent primary response may confer to the animal a critical advantage in the defense against pathogens. PMID:8418208

Development of Protective Immunity in New Zealand White Rabbits Challenged with Bacillus anthracis Spores and Treated with Antibiotics and Obiltoxaximab, a Monoclonal Antibody against Protective Antigen.

PubMed

Henning, Lisa N; Carpenter, Sarah; Stark, Gregory V; Serbina, Natalya V

2018-02-01

The recommended management of inhalational anthrax, a high-priority bioterrorist threat, includes antibiotics and antitoxins. Obiltoxaximab, a chimeric monoclonal antibody against anthrax protective antigen (PA), is licensed under the U.S. Food and Drug Administration's (FDA's) Animal Rule for the treatment of inhalational anthrax. Because of spore latency, disease reemergence after treatment cessation is a concern, and there is a need to understand the development of endogenous protective immune responses following antitoxin-containing anthrax treatment regimens. Here, acquired protective immunity was examined in New Zealand White (NZW) rabbits challenged with a targeted lethal dose of Bacillus anthracis spores and treated with antibiotics, obiltoxaximab, or a combination of both. Survivors of the primary challenge were rechallenged 9 months later and monitored for survival. Survival rates after primary and rechallenge for controls and animals treated with obiltoxaximab, levofloxacin, or a combination of both were 0, 65, 100, and 95%, and 0, 100, 95, and 89%, respectively. All surviving immune animals had circulating antibodies to PA and serum toxin-neutralizing titers prior to rechallenge. Following rechallenge, systemic bacteremia and toxemia were not detected in most animals, and the levels of circulating anti-PA IgG titers increased starting at 5 days postrechallenge. We conclude that treatment with obiltoxaximab, alone or combined with antibiotics, significantly improves the survival of rabbits that received a lethal inhalation B. anthracis spore challenge dose and does not interfere with the development of immunity. Survivors of primary challenge are protected against reexposure, have rare incidents of systemic bacteremia and toxemia, and have evidence of an anamnestic response. Copyright © 2018 Henning et al.

Subcomponent Vaccine Based on CTA1-DD Adjuvant with Incorporated UreB Class II Peptides Stimulates Protective Helicobacter pylori Immunity

PubMed Central

Nedrud, John G.; Bagheri, Nayer; Schön, Karin; Xin, Wei; Bergroth, Hilda; Eliasson, Dubravka Grdic; Lycke, Nils Y.

2013-01-01

A mucosal vaccine against Helicobacter pylori infection could help prevent gastric cancers and peptic ulcers. While previous attempts to develop such a vaccine have largely failed because of the requirement for safe and effective adjuvants or large amounts of well defined antigens, we have taken a unique approach to combining our strong mucosal CTA1-DD adjuvant with selected peptides from urease B (UreB). The protective efficacy of the selected peptides together with cholera toxin (CT) was first confirmed. However, CT is a strong adjuvant that unfortunately is precluded from clinical use because of its toxicity. To circumvent this problem we have developed a derivative of CT, the CTA1-DD adjuvant, that has been found safe in non-human primates and equally effective compared to CT when used intranasally. We genetically fused the selected peptides into the CTA1-DD plasmid and found after intranasal immunizations of Balb/c mice using purified CTA1-DD with 3 copies of an H. pylori urease T cell epitope (CTA1-UreB3T-DD) that significant protection was stimulated against a live challenge infection. Protection was, however, weaker than with the gold standard, bacterial lysate+CT, but considering that we only used a single epitope in nanomolar amounts the results convey optimism. Protection was associated with enhanced Th1 and Th17 immunity, but immunizations in IL-17A-deficient mice revealed that IL-17 may not be essential for protection. Taken together, we have provided evidence for the rational design of an effective mucosal subcomponent vaccine against H. pylori infection based on well selected protective epitopes from relevant antigens incorporated into the CTA1-DD adjuvant platform. PMID:24391754

45 CFR 5b.3 - Policy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PRIVACY ACT REGULATIONS § 5b.3 Policy. It is the policy of the Department to protect the privacy of individuals to the fullest extent possible... public is entitled to have under the Freedom of Information Act, 5 U.S.C. 552, and part 5 of this title. ...

45 CFR 5b.3 - Policy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Department of Health and Human Services GENERAL ADMINISTRATION PRIVACY ACT REGULATIONS § 5b.3 Policy. It is the policy of the Department to protect the privacy of individuals to the fullest extent possible... public is entitled to have under the Freedom of Information Act, 5 U.S.C. 552, and part 5 of this title. ...

45 CFR 5b.3 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PRIVACY ACT REGULATIONS § 5b.3 Policy. It is the policy of the Department to protect the privacy of individuals to the fullest extent possible... public is entitled to have under the Freedom of Information Act, 5 U.S.C. 552, and part 5 of this title. ...

Differential Expression of CD5 on B Lymphocytes in Cattle Infected with Mycobacterium avium subsp. paratuberculosis

USDA-ARS?s Scientific Manuscript database

CD5 is a cell surface molecule involved in antigen recognition and is present on all T lymphocytes and a subset of B lymphocytes. The purpose of this study was to examine CD5+ expression on peripheral blood B cells from healthy, noninfected cattle and cattle with subclinical and clinical paratubercu...

Prophylactic efficacy of high-molecular-weight antigenic fractions of a recent clinical isolate of Leishmania donovani against visceral leishmaniasis.

PubMed

Tripathi, P; Gupta, S K; Sinha, S; Sundar, S; Dube, A; Naik, S

2008-11-01

T-cell mediated immune responses are key determinants to the natural course of infection caused by intracellular parasites such as Leishmania. Thus, T-cell activating proteins of these microbes continue to generate active interest particularly in view of their possible role in the design and development of newer and more effective vaccines. We have recently reported the presence of T-cell immunostimulatory antigens with the high-molecular-weight (MW) fractions (134-64.2 kDa) of whole Leishmania donovani antigen (strain 2001), which stimulated variable amounts of IFN-gamma, IL-12 and IL-10 in exposed immune individuals. The present study was undertaken to further evaluate these high-MW antigenic fractions (MW range >100-60 kDa) for potential protective efficacy. The high-MW region of the parasite was resolved into five antigenic fractions (Prep A-E) using continuous elution gel electrophoresis. Prior to in vivo protection studies in hamsters, these fractions were used to evaluate in vitro cellular responses in eight Leishmania-exposed individuals and treated cured hamsters. The protective efficacy of prep (A + B), C, D and E in combination with BCG was evaluated in inbred hamsters using standard immunization protocol. Proliferative responses were seen in all eight of eight exposed individuals to prep D [median stimulation index (SI): 5.2 (range 3.9-7.1)] and E [median SI: 5.6 (range 4.4-8.2)], five of eight individuals to prep B and prep C and three of eight to prep A [median SI: 0.2 (range 0.1-7.2)]. The median proliferative responses to prep D and prep E were significantly higher than to fraction prep A; (P < 0.05) but not to prep B and prep C. However, prep A-E induced equivalent levels of IFN-gamma, IL-10 and IL-12 cytokines. Fractions D and E also exhibited marked parasite inhibition in spleen (52.5% and 73.7%) and liver (65% and 80.2%) as compared with prep (A + B) (23% in spleen and 24% in liver) and prep C (38% in spleen and 24% in liver). Prep D and prep E

Effects of SSM (specific substance maruyama) on HBe antigen-positive chronic hepatitis B -clinical efficacy and modulation of cytokines.

PubMed

Satomura, K; Yin, M; Sekiyama, T; Fujisaki, S; Aramaki, T; Okumura, H; Ohmoto, Y

2000-08-01

Twenty-three patients with HBe antigen-positive chronic hepatitis B were treated with capitalite first letters Maruyama (SSM). HBe antigen turned negative in 15 patients. The levels of various cytokines in pre- and post-treatment frozen serum samples from six patients whose HBe antigen turned negative and from five whose HBe antigen did not were examined. Reduction of serum interleukin (IL) -10 level to below 20 pg/ml was observed after SSM treatment in four of the six patients whose HBe antigen turned negative. SSM was found to stimulate the production of interferon (IFN) -gamma in peripheral blood cells from two healthy volunteers. This stimulatory effect was confirmed in 12 out of 24 healthy volunteers. SSM augmented the production of IFN-gamma in eight out of 10 patients with chronic hepatitis B and nine of 10 with hepatitis C. These results demonstrate for the first time that SSM stimulates the production of IFN-gamma in human peripheral blood cells and also suggest that treatment of HBe antigen-positive chronic hepatitis B patients with SSM leads to the clearance of HBe antigen and normalization of serum aspartate aminotransferase levels through inhibition of IL-10 and stimulation of IFN-gamma.

Antibody to hepatitis B core antigen levels in the natural history of chronic hepatitis B: a prospective observational study.

PubMed

Jia, Wei; Song, Liu-Wei; Fang, Yu-Qing; Wu, Xiao-Feng; Liu, Dan-Yang; Xu, Chun; Wang, Xiao-Mei; Wang, Wen; Lv, Dong-Xia; Li, Jun; Deng, Yong-Qiong; Wang, Yan; Huo, Na; Yu, Min; Xi, Hong-Li; Liu, Dan; Zhou, Yi-Xing; Wang, Gui-Qiang; Xia, Ning-Shao; Zhang, Ming-Xiang

2014-12-01

Previous studies have revealed antibody to hepatitis B core antigen (anti-HBc) levels as a predictor of treatment response in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients in both interferon and nucleos(t)ide analog therapy cohorts. However, there is no information about anti-HBc levels in the natural history of CHB. This study aimed to define anti-HBc levels of different phases in the natural history of CHB. Two hundred eleven treatment-naive CHB patients were included in the study. They were classified into 4 phases: immune tolerance (IT) phase (n = 39), immune clearance (IC) phase (n = 48), low or no-replicative (LR) phase (n = 55), and HBeAg-negative hepatitis (ENH, n = 69). Fifty patients who were HBsAg negative and anti-HBc positive were also recruited as past HBV infection (PBI) control group. Anti-HBc levels were measured by a newly developed double-sandwich immunoassay. Correlation of anti-HBc levels with alanine aminotransferase (ALT) and other HBV-related markers within each phase was performed. Serum anti-HBc levels were statistically significant between patients in different phases of CHB (P < 0.001). The median anti-HBc levels were: IT (3.17 log 10 IU/mL), IC (4.39 log 10 IU/mL), LR (3.29 log 10 IU/mL), ENH (4.12 log 10 IU/mL), and PBI (0.61 log 10 IU/mL). There existed a strong correlation in IC (r = 0.489, P < 0.001), a poor correlation in ENH (r = 0.275, P = 0.042), and no correlation in patients with ALT reached 5 times upper limit of normal (r = 0.120, P = 0.616). Anti-HBc levels show significant differences during the natural course of CHB. These results may provide some potentially useful insights into hepatitis B pathogenesis and immune activation against hepatitis B virus.

Lipopolysaccharide Antigens of Pseudomonas aeruginosa and Design of Novel Vaccines.

DTIC Science & Technology

1987-09-01

Pseudomonas aeruginosa, OA 1-C LChemical structure, Fisher immunotypes, M; ig0-Chain polysaccharide , and Synthetic antigens 19. ABSTRACT (Conu on rftvm if...have been characterized in our laboratories. Partial structures for the remaining two types have been elucidated. The O-chain polysaccharides of the... polysaccharide antigens for native structure, and (5) binding-site xa[lJ11:, of the antibodies using the synthetic antigens. b% B.. Sirmificance: General

Efficacy of an AS03A-adjuvanted split H5N1 influenza vaccine against an antigenically distinct low pathogenic H5N1 virus in pigs.

PubMed

De Vleeschauwer, Annebel R; Baras, Benoît; Kyriakis, Constantinos S; Jacob, Valérie; Planty, Camille; Giannini, Sandra L; Mossman, Sally; Van Reeth, Kristien

2012-08-10

We used the pig model of influenza to examine the efficacy of an AS03(A)-adjuvanted split H5N1 (A/Indonesia/05/2005) vaccine against challenge with a low pathogenic (LP) H5N1 avian influenza (AI) virus (duck/Minnesota/1525/1981) with only 85% amino acid homology in its HA1. Influenza seronegative pigs were vaccinated twice intramuscularly with adjuvanted vaccine at 3 antigen doses, unadjuvanted vaccine or placebo. All pigs were challenged 4 weeks after the second vaccination and euthanized 2 days later. After 2 vaccinations, all pigs in the adjuvanted vaccine groups had high hemagglutination inhibiting (HI) antibody titers to the vaccine strain (160-640), and lower antibody titers to the A/Vietnam/1194/04 H5N1 strain and to 2 LP H5 viruses with 90-91% amino acid homology to the vaccine strain (20-160). Eight out of 12 pigs had HI titers (10-20) to the challenge virus immediately before challenge. Neuraminidase inhibiting antibodies to the challenge virus were detected in most pigs (7/12) and virus neutralizing antibodies in all pigs. There was no antigen-dose dependent effect on the antibody response among the pigs immunized with adjuvanted H5N1 vaccines. After challenge, these pigs showed a complete clinical protection, reduced lung lesions and a significant protection against virus replication in the respiratory tract. Though the challenge virus showed only moderate replication efficiency in pigs, our study suggests that AS03(A)-adjuvanted H5N1 vaccine may confer a broader protection than generally assumed. The pros and cons of the pig as an H5N1 challenge model are also discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

A recombinant iron transport protein from Bordetella pertussis confers protection against Bordetella parapertussis.

PubMed

Alvarez Hayes, Jimena; Oviedo, Juan Marcos; Valdez, Hugo; Laborde, Juan Martín; Maschi, Fabricio; Ayala, Miguel; Shah, Rohan; Fernandez Lahore, Marcelo; Rodriguez, Maria Eugenia

2017-10-01

Whooping cough, which is caused by Bordetella pertussis and B. parapertussis, is a reemerging disease. New protective antigens are needed to improve the efficacy of current vaccines against both species. Using proteomic tools, it was here found that B. parapertussis expresses a homolog of AfuA, a previously reported new vaccine candidate against B. pertussis. It was found that this homolog, named AfuA Bpp , is expressed during B. parapertussis infection, exposed on the surface of the bacteria and recognized by specific antibodies induced by the recombinant AfuA cloned from B. pertussis (rAfuA). Importantly, the presence of the O-antigen, a molecule that has been found to shield surface antigens on B. parapertussis, showed no influence on antibody recognition of AfuA Bpp on the bacterial surface. The present study further showed that antibodies induced by immunization with the recombinant protein were able to opsonize B. parapertussis and promote bacterial uptake by neutrophils. Finally, it was shown that this antigen confers protection against B. parapertussis infection in a mouse model. Altogether, these results indicate that AfuA is a good vaccine candidate for acellular vaccines protective against both causative agents of whooping cough. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

32 CFR 806b.34 - Protecting records.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Protecting records. 806b.34 Section 806b.34... PROGRAM Protecting and Disposing of Records § 806b.34 Protecting records. Maintaining information privacy... contact with information in identifiable form. Protect information according to its sensitivity level...

32 CFR 806b.34 - Protecting records.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Protecting records. 806b.34 Section 806b.34... PROGRAM Protecting and Disposing of Records § 806b.34 Protecting records. Maintaining information privacy... contact with information in identifiable form. Protect information according to its sensitivity level...

32 CFR 806b.34 - Protecting records.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Protecting records. 806b.34 Section 806b.34... PROGRAM Protecting and Disposing of Records § 806b.34 Protecting records. Maintaining information privacy... contact with information in identifiable form. Protect information according to its sensitivity level...

32 CFR 806b.34 - Protecting records.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Protecting records. 806b.34 Section 806b.34... PROGRAM Protecting and Disposing of Records § 806b.34 Protecting records. Maintaining information privacy... contact with information in identifiable form. Protect information according to its sensitivity level...

32 CFR 806b.34 - Protecting records.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Protecting records. 806b.34 Section 806b.34... PROGRAM Protecting and Disposing of Records § 806b.34 Protecting records. Maintaining information privacy... contact with information in identifiable form. Protect information according to its sensitivity level...

Prevalence of Hepatitis B surface antigen among biomedical students of African descent in Usmanu Danfodiyo University, Sokoto, Nigeria.

PubMed

Okwesili, A N; Onuigwe, F U; Ibrahim, K; Buhari, H; Ibrahim, A; Jafaru, H; Erhabor, O; Onuigwe, F U; Isaac, Z; Ahmed, M H; Mainasara, M Y; Adias, T C; Yeldu, M H; Uko, E K; Udoma, F

2015-12-23

Hepatitis B (HB) is a serious global public health problem that put health professionals particularly at risk. The aim of this study was to investigate the prevalence of Hepatitis B surface antigen (HBsAg) among Biomedical Students of African descent attending Usmanu Danfodiyo University Sokoto in North-Western Nigeria. The Onsite HBsAg (CTK Biotech, USA) was used to detect the presence of hepatitis B surface antigen. We tested 186 consecutively-recruited students consisting of 147 males and 39 females aged 18-35 years (mean age 26 ± 2.0 years). Of the 186 students tested, 25 (13.4%) were positive for HBsAg. The prevalence of HBsAg was significantly higher among students in the 21-25 years age group. Hepatitis B vaccination uptake among students was 7%. Majority of subjects were single 173(93.1%) compared to married 13 (6.9%). Ethnic distribution of the subjects indicated that 104(55.9%) were Hausa compared to Yoruba 32 (17.2%), other ethnic groups 21(11.3%), Fulani 20(10.8%) and Igbo 9(4.8%). This study indicates a high prevalence of hepatitis B virus infection among Biomedical students in Sokoto, North Western, Nigeria. Finding from this study is enough justification for the implementation of a policy to routinely test students entering into the biomedical professions for Hepatitis B virus infection. There is the need to provide hepatitis B vaccination universally to all those who are found negative prior to commencement of their biomedical training. There is also need to educate students entering biomedical professions and healthcare workers on the modes of transmission and prevention, importance of being compliant with protective vaccination as well as the need to observe universal precaution and infection control guidelines during their training and future professional practice.

Genotypic evolution and antigenicity of H9N2 influenza viruses in Shanghai, China.

PubMed

Ge, Feifei; Li, Xin; Ju, Houbin; Yang, Dequan; Liu, Jian; Qi, Xinyong; Wang, Jian; Yang, Xianchao; Qiu, Yafeng; Liu, Peihong; Zhou, Jinping

2016-06-01

H9N2 influenza viruses have been circulating in China since 1994, but a systematic investigation of H9N2 in Shanghai has not previously been undertaken. Here, using 14 viruses we isolated from poultry and pigs in Shanghai during 2002 and 2006-2014, together with the commercial vaccine A/chicken/Shanghai/F/1998 (Ck/SH/F/98), we analyzed the evolution of H9N2 influenza viruses in Shanghai and showed that all 14 isolates originated from Ck/SH/F/98 antigenically. We evaluated the immune protection efficiency of the vaccine. Our findings demonstrate that H9N2 viruses in Shanghai have undergone extensive reassortment. Various genotypes emerged in 2002, 2006 and 2007, while during 2009-2014 only one genotype was found. Four antigenic groups, A-D, could be identified among the 14 isolates and a variety of antigenically distinct H9N2-virus-derived avian influenza viruses (AIVs) circulated simultaneously in Shanghai during this period. Challenge experiments using vaccinated chickens indicated that the vaccine prevented shedding of antigenic group A and B viruses, but not those of the more recent groups C and D. Genetic analysis showed that compared to the vaccine strain, representative viruses of antigenic groups C and D possess greater numbers of amino acid substitutions in the hemagglutinin (HA) protein than viruses in antigenic groups A and B. Many of these substitutions are located in antigenic sites. Our results indicate that the persistence of H9N2 AIV in China might be due to incomplete vaccine protection and that the avian influenza vaccine should be regularly evaluated and updated to maintain optimal protection.

A Plasmodium vivax Plasmid DNA- and Adenovirus-Vectored Malaria Vaccine Encoding Blood-Stage Antigens AMA1 and MSP142 in a Prime/Boost Heterologous Immunization Regimen Partially Protects Aotus Monkeys against Blood-Stage Challenge.

PubMed

Obaldia, Nicanor; Stockelman, Michael G; Otero, William; Cockrill, Jennifer A; Ganeshan, Harini; Abot, Esteban N; Zhang, Jianfeng; Limbach, Keith; Charoenvit, Yupin; Doolan, Denise L; Tang, De-Chu C; Richie, Thomas L

2017-04-01

Malaria is caused by parasites of the genus Plasmodium , which are transmitted to humans by the bites of Anopheles mosquitoes. After the elimination of Plasmodium falciparum , it is predicted that Plasmodium vivax will remain an important cause of morbidity and mortality outside Africa, stressing the importance of developing a vaccine against P. vivax malaria. In this study, we assessed the immunogenicity and protective efficacy of two P. vivax antigens, apical membrane antigen 1 (AMA1) and the 42-kDa C-terminal fragment of merozoite surface protein 1 (MSP1 42 ) in a plasmid recombinant DNA prime/adenoviral (Ad) vector boost regimen in Aotus monkeys. Groups of 4 to 5 monkeys were immunized with plasmid DNA alone, Ad alone, prime/boost regimens with each antigen, prime/boost regimens with both antigens, and empty vector controls and then subjected to blood-stage challenge. The heterologous immunization regimen with the antigen pair was more protective than either antigen alone or both antigens delivered with a single vaccine platform, on the basis of their ability to induce the longest prepatent period and the longest time to the peak level of parasitemia, the lowest peak and mean levels of parasitemia, the smallest area under the parasitemia curve, and the highest self-cure rate. Overall, prechallenge MSP1 42 antibody titers strongly correlated with a decreased parasite burden. Nevertheless, a significant proportion of immunized animals developed anemia. In conclusion, the P. vivax plasmid DNA/Ad serotype 5 vaccine encoding blood-stage parasite antigens AMA1 and MSP1 42 in a heterologous prime/boost immunization regimen provided significant protection against blood-stage challenge in Aotus monkeys, indicating the suitability of these antigens and this regimen for further development. Copyright © 2017 American Society for Microbiology.

Dysfunctional BLK in common variable immunodeficiency perturbs B-cell proliferation and ability to elicit antigen-specific CD4+ T-cell help.

PubMed

Compeer, Ewoud B; Janssen, Willemijn; van Royen-Kerkhof, Annet; van Gijn, Marielle; van Montfrans, Joris M; Boes, Marianne

2015-05-10

Common Variable Immunodeficiency (CVID) is the most prevalent primary antibody deficiency, and characterized by defective generation of high-affinity antibodies. Patients have therefore increased risk to recurrent infections of the respiratory and intestinal tract. Development of high-affinity antigen-specific antibodies involves two key actions of B-cell receptors (BCR): transmembrane signaling through BCR-complexes to induce B-cell differentiation and proliferation, and BCR-mediated antigen internalization for class-II MHC-mediated presentation to acquire antigen-specific CD4(+) T-cell help.We identified a variant (L3P) in the B-lymphoid tyrosine kinase (BLK) gene of 2 related CVID-patients, which was absent in healthy relatives. BLK belongs to the Src-kinases family and involved in BCR-signaling. Here, we sought to clarify BLK function in healthy human B-cells and its association to CVID.BLK expression was comparable in patient and healthy B-cells. Functional analysis of L3P-BLK showed reduced BCR crosslinking-induced Syk phosphorylation and proliferation, in both primary B-cells and B-LCLs. B-cells expressing L3P-BLK showed accelerated destruction of BCR-internalized antigen and reduced ability to elicit CD40L-expression on antigen-specific CD4(+) T-cells.In conclusion, we found a novel BLK gene variant in CVID-patients that causes suppressed B-cell proliferation and reduced ability of B-cells to elicit antigen-specific CD4(+) T-cell responses. Both these mechanisms may contribute to hypogammaglobulinemia in CVID-patients.

Assessment of the repeatability and border-plate effects of the B158/B60 enzyme-linked-immunosorbent assay for the detection of circulating antigens (Ag-ELISA) of Taenia saginata.

PubMed

Jansen, Famke; Dorny, Pierre; Berkvens, Dirk; Van Hul, Anke; Van den Broeck, Nick; Makay, Caroline; Praet, Nicolas; Gabriël, Sarah

2016-08-30

The monoclonal antibody-based circulating antigen detecting ELISA (B158/B60 Ag-ELISA) has been used elaborately in several studies for the diagnosis of human, bovine and porcine cysticercosis. Interpretation of test results requires a good knowledge of the test characteristics, including the repeatability and the effect of the borders of the ELISA plates. Repeatability was tested for 4 antigen-negative and 5 antigen-positive reference bovine serum samples by calculating the Percentage Coefficient of Variation (%CV) within and between plates, within and between runs, overall, for two batches of monoclonal antibodies and by 2 laboratory technicians. All CV values obtained were below 20% (except one: 24.45%), which indicates a good repeatability and a negligible technician error. The value of 24.45% for indicating the variability between batches of monoclonal antibodies for one positive sample is still acceptable for repeatability measures. Border effects were determined by calculating the %CV values between the inner and outer wells of one plate for 2 positive serum samples. Variability is a little more present in the outer wells but this effect is very small and no significant border effect was found. Copyright © 2016 Elsevier B.V. All rights reserved.

An overview on the identification of MAIT cell antigens.

PubMed

Kjer-Nielsen, Lars; Corbett, Alexandra J; Chen, Zhenjun; Liu, Ligong; Mak, Jeffrey Y W; Godfrey, Dale I; Rossjohn, Jamie; Fairlie, David P; McCluskey, James; Eckle, Sidonia B G

2018-04-14

Mucosal Associated Invariant T (MAIT) cells are restricted by the monomorphic MHC class I-like molecule, MHC-related protein-1 (MR1). Until 2012, the origin of the MAIT cell antigens (Ags) was unknown, although it was established that MAIT cells could be activated by a broad range of bacteria and yeasts, possibly suggesting a conserved Ag. Using a combination of protein chemistry, mass spectrometry, cellular biology, structural biology and chemistry, we discovered MAIT cell ligands derived from folic acid (vitamin B9) and from an intermediate in the microbial biosynthesis of riboflavin (vitamin B2). While the folate derivative 6-formylpterin (6-FP) generally inhibited MAIT cell activation, two riboflavin pathway derivatives, 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU) and 5-(2-oxoethylideneamino)-6-D-ribitylaminouracil (5-OE-RU), were potent MAIT cell agonists. Other intermediates and derivatives of riboflavin synthesis displayed weak or no MAIT cell activation. Collectively, these studies revealed that in addition to peptide and lipid-based Ags, small molecule natural product metabolites are also ligands that can activate T cells expressing αβ T cell receptors, and here we recount this discovery. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Immunization of Mice with Anthrax Protective Antigen Limits Cardiotoxicity but Not Hepatotoxicity Following Lethal Toxin Challenge.

PubMed

Devera, T Scott; Prusator, Dawn K; Joshi, Sunil K; Ballard, Jimmy D; Lang, Mark L

2015-06-25

Protective immunity against anthrax is inferred from measurement of vaccine antigen-specific neutralizing antibody titers in serum samples. In animal models, in vivo challenges with toxin and/or spores can also be performed. However, neither of these approaches considers toxin-induced damage to specific organ systems. It is therefore important to determine to what extent anthrax vaccines and existing or candidate adjuvants can provide organ-specific protection against intoxication. We therefore compared the ability of Alum, CpG DNA and the CD1d ligand α-galactosylceramide (αGC) to enhance protective antigen-specific antibody titers, to protect mice against challenge with lethal toxin, and to block cardiotoxicity and hepatotoxicity. By measurement of serum cardiac Troponin I (cTnI), and hepatic alanine aminotransferase (ALT), and aspartate aminotransferase (AST), it was apparent that neither vaccine modality prevented hepatic intoxication, despite high Ab titers and ultimate survival of the subject. In contrast, cardiotoxicity was greatly diminished by prior immunization. This shows that a vaccine that confers survival following toxin exposure may still have an associated morbidity. We propose that organ-specific intoxication should be monitored routinely during research into new vaccine modalities.

Expression of the human hepatitis B virus large surface antigen gene in transgenic tomato plants.

PubMed

Lou, Xiao-Ming; Yao, Quan-Hong; Zhang, Zhen; Peng, Ri-He; Xiong, Ai-Sheng; Wang, Hua-Kun

2007-04-01

The original hepatitis B virus (HBV) large surface antigen gene was synthesized. In order to optimize the expression of this gene in tomato plants, the tobacco pathogenesis-related protein S signal peptide was fused to the 5' end of the modified gene and the sequence encoding amino acids S, E, K, D, E, and L was placed at the 3' end. The gene encoding the modified HBV large surface antigen under the control of a fruit-specific promoter was constructed and expressed in transgenic tomato plants. The expression of the antigen from transgenic plants was confirmed by PCR and reverse transcriptase PCR. Enzyme-linked immunoassays using a monoclonal antibody directed against human serum-derived HBsAg revealed that the maximal level of HBsAg was about 0.02% of the soluble protein in transgenic tomato fruit. The amount of HBsAg in mature fruits was found to be 65- to 171-fold larger than in small or medium fruits and leaf tissues. Examination of transgenic plant samples by transmission electron microscopy proved that HBsAg had been expressed and had accumulated. The HBsAg protein was capable of assembling into capsomers and virus-like particles. To our knowledge, this is the first time the HBV large surface antigen has been expressed in plants. This work suggests the possibility of producing a new alternative vaccine for human HBV.

PD-1 suppresses development of humoral responses that protect against Tn-bearing tumors

PubMed Central

Haro, Marcela A.; Littrell, Chad A.; Yin, Zhaojun; Huang, Xuefei; Haas, Karen M.

2017-01-01

Tn is a carbohydrate antigen uniquely exposed on tumor mucins and thus, an ideal target for immunotherapy. However, it has been difficult to elicit protective antibody responses against Tn antigen and other tumor associated carbohydrate antigens. Our study demonstrates this can be attributed to PD-1 immuno-inhibition. Our data show a major role for PD-1 in suppressing mucin- and Tn-specific B-cell activation, expansion, and antibody production important for protection against Tn-bearing tumor cells. These Tn/mucin-specific B cells belong to the innate-like B-1b cell subset typically responsible for T cell–independent antibody responses. Interestingly, PD-1–mediated regulation is B cell–intrinsic and CD4+ cells play a key role in supporting Tn/mucin-specific B cell antibody production in the context of PD-1 deficiency. Mucin-reactive antibodies produced in the absence of PD-1 inhibition largely belong to the IgM subclass and elicit potent antitumor effects via a complement-dependent mechanism. The identification of this role for PD-1 in regulating B cell–dependent antitumor immunity to Tn antigen highlights an opportunity to develop new therapeutic strategies targeting tumor associated carbohydrate antigens. PMID:27856425

Efficient Culture of Human Naïve and Memory B cells for Use as Antigen-presenting Cells

PubMed Central

Su, Kuei-Ying; Watanabe, Akiko; Yeh, Chen-Hao; Kelsoe, Garnett; Kuraoka, Masayuki

2016-01-01

The ability to culture and expand B cells in vitro has become a useful tool for studying human immunity. A limitation of current methods for human B-cell culture is the capacity to support mature B-cell proliferation. We have developed a culture method to support the efficient activation and proliferation of both naïve and memory human B cells. This culture supports extensive B-cell proliferation, with approximately 103-fold increases following 8 days in culture, and 106-fold increases when cultures are split and cultured for 8 more days. In culture, a significant fraction of naïve B cells undergo isotype switching and differentiate into plasmacytes. Culture-derived (CD) B cells are readily cryopreserved, and when recovered, retain their ability to proliferate and differentiate. Significantly, proliferating CD B cells express high levels of MHCII, CD80, and CD86. CD B cells act as APCs and present both alloantigens and microbial antigens to T cells. We are able to activate and expand antigen-specific memory B cells; these cultured cells are highly effective in presenting antigen to T cells. We have characterized the TCR repertoire of rare antigen-specific CD4+ T cells that proliferated in response to tetanus toxoid (TT) presented by autologous CD B cells. TCR Vβ usage by TT-activated CD4+ T cells differs from both resting and unspecifically activated CD4+ T cells. Moreover, we found that TT-specific TCR Vβ usage by CD4+ T cells was substantially different between donors. This culture method provides a platform for studying the BCR and TCR repertoires within a single individual. PMID:27815447

Genetic diversity and antigenicity variation of Babesia bovis merozoite surface antigen-1 (MSA-1) in Thailand.

PubMed

Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Takemae, Hitoshi; Simking, Pacharathon; Jittapalapong, Sathaporn; Igarashi, Ikuo; Yokoyama, Naoaki

2016-07-01

Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our phylogenetic analysis, Thai msa-1 gene sequences occurred in 18 clades; seven among them were composed of sequences exclusively from Thailand. To investigate differential antigenicity of isolated MSA-1 proteins, we expressed and purified eight recombinant MSA-1 (rMSA-1) proteins, including an rMSA-1 from B. bovis Texas (T2Bo) strain and seven rMSA-1 proteins based on the Thai msa-1 sequences. When these antigens were analyzed in a western blot assay, anti-T2Bo cattle serum strongly reacted with the rMSA-1 from T2Bo, as well as with three other rMSA-1 proteins that shared 54.9-68.4% sequence similarity with T2Bo MSA-1. In contrast, no or weak reactivity was observed for the remaining rMSA-1 proteins, which shared low sequence similarity (35.0-39.7%) with T2Bo MSA-1. While demonstrating the high genetic diversity of the B. bovis msa-1 gene in Thailand, the present findings suggest that the genetic diversity results in antigenicity variations among the MSA-1 antigens of B. bovis in Thailand. Copyright © 2016 Elsevier B.V. All rights reserved.

HLA-B27 antigen frequency among suspected Spondyloarthropathy patients attaining a tertiary level hospital of Bangladesh.

PubMed

Nessa, A; Tabassum, S; Sultana, S

2014-12-01

Human leukocyte antigen B27 (HLA-B27), a class I molecules of the major histocompatibility complex has a strong disease association with different types of spondarthropathies (SpA). The strength of this disease association varies markedly among racial and ethnic populations. The present study aimed to identify the HLA-B27 antigen frequencies among suspected SpA patients as well as healthy Bangladeshi individuals. The frequency of HLA-B27 was determined in 1500 patients and 1000 healthy subjects attending the Bangabandhu Sheikh Mujib Medical University (BSMMU). HLA-B 27 typing was done by microlymphocytotoxicity test using commercial kit. A total of 738 (49.2%) suspected SpA patients and 107 (10.7%) healthy subjects tested positive for HLA-B27 antigen with higher frequency among younger age groups (54.9%, 52.4% and 56.2% in 0-14 years, 15-24 years and 25-34 years of age respectively). The male female positivity was almost same (11.4% and 9.6%) among control group, but in patient group it was 53.0% and 41.2% respectively. The findings of this hospital based study showed a high frequency of HLA-B27 among suspected SpA patients with male preponderance which is comparable with neighboring countries.

Polymorphisms of human leukocyte antigen B*27 on clinical phenotype of spondyloarthritis in Chinese.

PubMed

Ma, Hai-Jun; Yin, Qing-Feng; Liu, Yun; Wu, Yin; Zhu, Tie-Chui; Guo, Ming-Hao

2018-02-01

In recent years, an ever-increasing number of alleles of human leukocyte antigen B*27 (HLA-B*27) have been identified. This study aimed to establish an updated method for HLA-B*27 subtyping, and to investigate the impact of HLA-B*27 polymorphisms on the clinical phenotype of spondyloarthritis (SpA). Overall, 184 SpA patients were recruited for analyzing diversity of HLA-B*27 via an updated high-resolution polymerase chain reaction amplification with sequence specific primers (PCR-SSP). The prevalence of HLA-B*27 was 94.0%, and four subtypes were identified including HLA-B*2704 (77.5%), B*2705 (20.2%), B*2707 (1.7%), and B*2724 (0.6%). There was an obvious male predominance (P=.05) and markedly elevated C-reaction protein (CRP) in B*27 positive SpA (P<.01). In multivariate linear regression analysis, the elevated CRP was positively associated with HLA-B*27 positivity (regression coefficient B=46.1, P=.0003), grade of sacroiliitis (B=47.5, P=.0032), and male gender (B=20.4, P=.0041). Notably, a male predilection was also found in B*2705 positive SpA while B*2707 was associated with older age, higher positive family history, and higher prevalence of extra-articular features (all P<.05). In this study, an updated PCR-SSP technique to identify increasing alleles of HLA-B*27 was developed and their different effects on clinical manifestations of SpA were demonstrated. Genotyping of HLA-B*27 would shed light on our understanding of the pathogenesis of SpA. © 2017 Wiley Periodicals, Inc.

A small antigenic determinant of the Chikungunya virus E2 protein is sufficient to induce neutralizing antibodies which are partially protective in mice.

PubMed

Weber, Christopher; Büchner, Sarah M; Schnierle, Barbara S

2015-04-01

The mosquito-borne Chikungunya virus (CHIKV) causes high fever and severe joint pain in humans. It is expected to spread in the future to Europe and has recently reached the USA due to globalization, climate change and vector switch. Despite this, little is known about the virus life cycle and, so far, there is no specific treatment or vaccination against Chikungunya infections. We aimed here to identify small antigenic determinants of the CHIKV E2 protein able to induce neutralizing immune responses. E2 enables attachment of the virus to target cells and a humoral immune response against E2 should protect from CHIKV infections. Seven recombinant proteins derived from E2 and consisting of linear and/or structural antigens were created, and were expressed in and purified from E. coli. BALB/c mice were vaccinated with these recombinant proteins and the mouse sera were screened for neutralizing antibodies. Whereas a linear N-terminally exposed peptide (L) and surface-exposed parts of the E2 domain A (sA) alone did not induce neutralizing antibodies, a construct containing domain B and a part of the β-ribbon (called B+) was sufficient to induce neutralizing antibodies. Furthermore, domain sA fused to B+ (sAB+) induced the highest amount of neutralizing antibodies. Therefore, the construct sAB+ was used to generate a recombinant modified vaccinia virus Ankara (MVA), MVA-CHIKV-sAB+. Mice were vaccinated with MVA-CHIKV-sAB+ and/or the recombinant protein sAB+ and were subsequently challenged with wild-type CHIKV. Whereas four vaccinations with MVA-CHIKV-sAB+ were not sufficient to protect mice from a CHIKV infection, protein vaccination with sAB+ markedly reduced the viral titers of vaccinated mice. The recombinant protein sAB+ contains important structural antigens for a neutralizing antibody response in mice and its formulation with appropriate adjuvants might lead to a future CHIKV vaccine.

Synergistic protection of mice against plague with monoclonal antibodies specific for the F1 and V antigens of Yersinia pestis.

PubMed

Hill, Jim; Copse, Catherine; Leary, Sophie; Stagg, Anthony J; Williamson, E Diane; Titball, Richard W

2003-04-01

Monoclonal antibodies specific for Yersinia pestis V antigen and F1 antigen, administered singly or in combination, protected mice in models of bubonic and pneumonic plague. Antibodies showed synergy when administered prophylactically and as a therapy 48 h postinfection. Monoclonal antibodies therefore have potential as a treatment for plague.

Protection conferred by recombinant Yersinia pestis antigens produced by a rapid and highly scalable plant expression system

PubMed Central

Santi, Luca; Giritch, Anatoli; Roy, Chad J.; Marillonnet, Sylvestre; Klimyuk, Victor; Gleba, Yuri; Webb, Robert; Arntzen, Charles J.; Mason, Hugh S.

2006-01-01

Plague is still an endemic disease in different regions of the world. Increasing reports of incidence, the discovery of antibiotic resistance strains, and concern about a potential use of the causative bacteria Yersinia pestis as an agent of biological warfare have highlighted the need for a safe, efficacious, and rapidly producible vaccine. The use of F1 and V antigens and the derived protein fusion F1-V has shown great potential as a protective vaccine in animal studies. Plants have been extensively studied for the production of pharmaceutical proteins as an inexpensive and scalable alternative to common expression systems. In the current study the recombinant plague antigens F1, V, and fusion protein F1-V were produced by transient expression in Nicotiana benthamiana by using a deconstructed tobacco mosaic virus-based system that allowed very rapid and extremely high levels of expression. All of the plant-derived purified antigens, administered s.c. to guinea pigs, generated systemic immune responses and provided protection against an aerosol challenge of virulent Y. pestis. PMID:16410352

Major antigenic determinants of F and ColB2 pili.

PubMed Central

Finlay, B B; Frost, L S; Paranchych, W; Parker, J M; Hodges, R S

1985-01-01

F-like conjugative pili are expressed by plasmids with closely related transfer systems. They are tubular filaments that are composed of repeating pilin subunits arranged in a helical array. Both F and ColB2 pilin have nearly identical protein sequences, and both contain an acetylated amino-terminal alanine residue. However, they differ by a few amino acid residues at their amino termini. Rabbit antisera raised against purified F and ColB2 pili are immunologically cross-reactive by only 25%, as measured by a competition enzyme-linked immunosorbent assay (ELISA). A tryptic peptide corresponding to the first 15 amino acid residues of ColB2 pilin was isolated and found to remove nearly 80% of ColB2 pilus-directed rabbit antibodies. The corresponding tryptic peptide from F pilin, which reacted with anti-F pilus antibodies to remove 80%, was less than 20% reactive with anti-ColB2 pilus antiserum. Cleavage of these peptides with cyanogen bromide (at a methionine residue approximately in the middle of the peptide) did not affect the antigenicity of these peptides. Synthetic N alpha-acetylated peptides corresponding to the first eight amino acids of F pilin (Ac-Ala-Gly-Ser-Ser-Gly-Gln-Asp-Leu-COOH) and the first six amino acids of ColB2 pilin (Ac-Ala-Gln-Gly-Gln-Asp-Leu-COOH) were prepared and tested by competition ELISA with homologous and heterologous anti-pilus antisera. The F peptide F(1-8) inhibited the interaction of F pili and anti-F pilus antiserum to 80%, while the ColB2 peptide ColB2(1-6) inhibited anti-ColB2 pilus antiserum reacting with ColB2 pili by greater than 60%. The two peptides F(1-8) and ColB2(1-6) were inactive by competition ELISAs with heterologous antisera. These results suggest that the major antigenic determinant of both F and ColB2 pili is at the amino terminus of the pilin subunit and that 80% of antibodies raised against these pili are specific for this region of the pilin molecule. PMID:2409073

The HLA Dictionary 2001: a summary of HLA-A, -B, -C, -DRB1/3/4/5 and -DQB1 alleles and their association with serologically defined HLA-A, -B, -C, -DR and -DQ antigens.

PubMed

Schreuder, G M; Hurley, C K; Marsh, S G; Lau, M; Maiers, M; Kollman, C; Noreen, H J

2001-12-01

This report presents the serological equivalents of 123 HLA-A, 272 HLA-B and 155 HLA-DRB1 alleles. The equivalents cover over 64% of the presently identified HLA-A, -B and -DRB1 alleles. The dictionary is an update of the one published in 1999 (<1>Schreuder et al., 1999, Tissue Antigens, 54, 409) and also includes equivalents for HLA-C, DRB3, DRB4, DRB5 and DQB1 alleles. The data summarize information obtained by the WHO Nomenclature Committee for Factors of the HLA System, the International Cell Exchange (UCLA), the National Marrow Donor Program (NMDP) and individual laboratories. In addition, a listing is provided of alleles that are expressed as antigens with serological reaction patterns that differ from the well-established HLA specificities. The equivalents provided will be useful in guiding searches for unrelated hematopoietic stem cell donors in which patients and/or potential donors are typed by either serology or DNA-based methods. These equivalents will also serve typing and matching procedures for organ transplant programmes where HLA typings from donors and from recipients on waiting lists represent mixtures of serological and molecular typings. The tables with HLA equivalents and a questionnaire for submission of serological reaction patterns for poorly identified allelic products will also be available on the WMDA web page: www.worldmarrow.org

The antigenic complex in HIT binds to B cells via complement and complement receptor 2 (CD21)

PubMed Central

Khandelwal, Sanjay; Lee, Grace M.; Hester, C. Garren; Poncz, Mortimer; McKenzie, Steven E.; Sachais, Bruce S.; Rauova, Lubica; Kelsoe, Garnett; Cines, Douglas B.; Frank, Michael

2016-01-01

Heparin-induced thrombocytopenia is a prothrombotic disorder caused by antibodies to platelet factor 4 (PF4)/heparin complexes. The mechanism that incites such prevalent anti-PF4/heparin antibody production in more than 50% of patients exposed to heparin in some clinical settings is poorly understood. To investigate early events associated with antigen exposure, we first examined the interaction of PF4/heparin complexes with cells circulating in whole blood. In healthy donors, PF4/heparin complexes bind preferentially to B cells (>90% of B cells bind to PF4/heparin in vitro) relative to neutrophils, monocytes, or T cells. Binding of PF4 to B cells is heparin dependent, and PF4/heparin complexes are found on circulating B cells from some, but not all, patients receiving heparin. Given the high proportion of B cells that bind PF4/heparin, we investigated complement as a mechanism for noncognate antigen recognition. Complement is activated by PF4/heparin complexes, co-localizes with antigen on B cells from healthy donors, and is present on antigen-positive B cells in patients receiving heparin. Binding of PF4/heparin complexes to B cells is mediated through the interaction between complement and complement receptor 2 (CR2 [CD21]). To the best of our knowledge, these are the first studies to demonstrate complement activation by PF4/heparin complexes, opsonization of PF4/heparin to B cells via CD21, and the presence of complement activation fragments on circulating B cells in some patients receiving heparin. Given the critical contribution of complement to humoral immunity, our observations provide new mechanistic insights into the immunogenicity of PF4/heparin complexes. PMID:27412887

Serodiagnostic potential of immuno-PCR using a cocktail of mycobacterial antigen 85B, ESAT-6 and cord factor in tuberculosis patients.

PubMed

Singh, Netrapal; Sreenivas, Vishnubhatla; Sheoran, Abhishek; Sharma, Suman; Gupta, Krishna B; Khuller, Gopal K; Mehta, Promod K

2016-01-01

A novel indirect immuno-polymerase chain reaction (I-PCR) assay was developed for the detection of circulating anti-Ag85B (antigen 85B, Rv1886c), anti-ESAT-6 (early secretory antigenic target-6, Rv3875) and anti-cord factor (trehalose 6,6'-dimycolate) antibodies from the sera samples of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) patients and the results were compared with an analogous enzyme-linked immunosorbent assay (ELISA). We covalently attached the amino-modified reporter DNA to the dithiothreitol (DTT)-reduced anti-human IgG antibody through a chemical linker succinimidyl 4-[N-maleimidomethyl]-cyclohexane-1-carboxylate (SMCC). The detection of cocktail of anti-Ag85B, anti-ESAT-6 and anti-cord factor antibodies was found to be superior to the detection of individual antibodies. The sensitivities of 89.5% and 77.5% with I-PCR and 70.8% and 65% with ELISA were observed in smear-positive and smear-negative PTB cases, respectively with high specificity (90.9%). On the other hand, a sensitivity of 77.5% with I-PCR and 65% with ELISA was observed in EBTB cases. The detection of cocktail of antibodies by I-PCR is likely to improve the utility of existing algorithms for TB diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Immune responses and protective efficacy of the gene vaccine expressing Ag85B and ESAT6 fusion protein from Mycobacterium tuberculosis.

PubMed

Chang-hong, Shi; Xiao-wu, Wang; Hai, Zhang; Ting-fen, Zhang; Li-Mei, Wang; Zhi-kai, Xu

2008-04-01

Genetic immunity is a new promising approach for the development of novel tuberculosis vaccines. In this study, it is shown that DNA vaccines expressing the fusion protein of antigen 85B (Ag85B) and early secreted antigenic target 6-kDa antigen (ESAT6) can induce high levels of specific IgG2a antibody subtype in the mice. With the prolongation of postimmunization time, the levels of IgG2a antibody decrease gradually. Although a high-level specific IgG2a antibody subtype is also elicited by classical BCG, the ratio of antibody subtypes IgG2a to IgG1 changes 4 weeks after immunization, and IgG1 is gradually shifted to the main antibody subtype. DNA vaccines also elicit cellular immunity as shown by specific spleen lymphocytes proliferation to Ag85B or ESAT6 protein and the production of high levels of IFN-gamma and IL-2, which is similar to that elicited by BCG. Vaccination of mice with DNA vaccines expressing the fusion protein Ag85B-ESAT6 results in a significant level of protection against the subsequent high-dose challenge with virulent Mycobacterium tuberculosis (MTB) H37Rv. Dramatic reduction in the number of MTB colony-forming units in the spleens and lungs is observed. Pathological examination showed that recombinant plasmid and BCG groups have only minor damage and organizational structures that are kept relatively complete, while in the control group, spleens and lungs are damaged seriously. Therefore, although the reducing degree of mycobacterial loads in the organ of mice immunized with recombinant plasmid is not more than that of BCG, through the analysis of pathological changes, we may conclude that the protective effect provided by DNA vaccine expressing the Ag85B-ESAT6 fusion protein is equivalent to that afforded by the classical BCG.

Presentation of antigen to T lymphocytes by non-immune B-cell hybridoma clones: evidence for specific and non-specific presentation

NASA Technical Reports Server (NTRS)

Cohly, H. H.; Morrison, D. R.; Zouhair Atassi, M. Z.

1989-01-01

Non-immune SJL (H-2s) spleen cells were fused with non-secreting, non-antigen presenting (H-2d) Balb/c 653-myeloma cells and the hybridomas were cloned by two limiting dilutions. The resulting hybrid B-cell clones were tested for their antigen presentation capability to SJL T-cell lines that were specific for either lysozyme or myoglobin. In proliferative assays, 53% of the antigen presenting B-cell clones presented both myoglobin and lysozyme (general presenters) while the other 47% presented specifically either myoglobin or lysozyme (specific presenters). The ability to selectively present either myoglobin or lysozyme indicates that antigen presentation at the clonal level can be specific or non-specific depending on the particular B-cell clone.

Antigenicity and Immunogenicity in HIV-1 Antibody-Based Vaccine Design

PubMed Central

Kong, Leopold; Sattentau, Quentin J

2012-01-01

Neutralizing antibodies can protect from infection by immunodeficiency viruses. However, the induction by active vaccination of antibodies that can potently neutralize a broad range of circulating virus strains is a goal not yet achieved, despite more than 2 decades of research. Here we review progress made in the field, from early empirical studies to today’s rational structure-based vaccine antigen design. We discuss the existence of broadly neutralizing antibodies, their implications for epitope discovery and recent progress made in antigen design. Finally, we consider the relationship between antigenicity and immunogenicity for B cell recognition and antibody production, a major hurdle for rational vaccine design to overcome. PMID:23227445

Discovering naturally processed antigenic determinants that confer protective T cell immunity