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Sample records for encoded antigens recombinant

  1. Immunogenicity of recombinant attenuated Salmonella enterica serovar Typhimurium vaccine strains carrying a gene that encodes Eimeria tenella antigen S07

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an attempt to develop an efficacious vaccine against avian coccidiosis, research was conducted using Type III Secretion System (TTSS) of Salmonella to deliver Eimeria antigens into the cytoplasm of host cells. Once delivered, recombinant protein may enter the MHC I antigen processing pathway for...

  2. Vaccination with replication-deficient recombinant adenoviruses encoding the main surface antigens of toxoplasma gondii induces immune response and protection against infection in mice.

    PubMed

    Caetano, Bráulia C; Bruña-Romero, Oscar; Fux, Blima; Mendes, Erica A; Penido, Marcus L O; Gazzinelli, Ricardo T

    2006-04-01

    We have generated recombinant adenoviruses encoding three genetically modified surface antigens (SAGs) of the parasite Toxoplasma gondii, that is, AdSAG1, AdSAG2, and AdSAG3. Modifications included the removal of their glycosylphosphatidylinositol (GPI) anchoring motifs and, in some cases, the exchange of the native signal peptide for influenza virus hemagglutinin signal sequence. Adenovirus immunization of BALB/c mice elicited potent antibody responses against each protein, displaying a significant bias toward a helper T cell type 1 (Th1) profile in animals vaccinated with AdSAG1. Furthermore, the presence of parasite-specific IFN-gamma-producing T cells was analyzed by proliferation assays and enzyme-linked immunospot assays in the same animals. Splenocytes from immunized mice secreted IFN-gamma after in vitro stimulation with tachyzoite lysate antigen or with a fraction enriched for membrane-purified GPI-anchored proteins (F3) from the T. gondii tachyzoite surface. Epitopes recognized by CD8+ T cells were identified in SAG1 and SAG3, but not SAG2, sequences, although this protein also induced a specific response. We also tested the capacity of the immune responses detected to protect mice against a challenge with live T. gondii parasites. Although no protection was observed against tachyzoites of the highly virulent RH strain, a significant reduction in cyst loads in the brain was observed in animals challenged with the P-Br strain. Thus, up to 80% of the cysts were eliminated from animals vaccinated with a mixture of the three recombinant viruses. Because adenoviruses seemed capable of inducing Th1-biased protective immune responses against T. gondii antigens, other parasite antigens should be tested alone or in combination with those described here to further develop a protective vaccine against toxoplasmosis. PMID:16610929

  3. Vaccination of mice against canine distemper virus-induced encephalitis with vaccinia virus recombinants encoding measles or canine distemper virus antigens.

    PubMed

    Wild, T F; Bernard, A; Spehner, D; Villeval, D; Drillien, R

    1993-01-01

    Measles and canine distemper are caused by serologically related viruses. Although dogs immunized with measles virus (MV) do not elicit canine distemper virus (CDV) neutralizing antibodies, they are protected against the fatal disease. To investigate the potential role of the MV antigens in protection against CDV, we have immunized mice with vaccinia virus (VV) recombinants expressing the MV haemagglutinin (HA), fusion (F), nucleoprotein (NP) and matrix (M) antigens and challenged them with CDV. A partial protection was observed with the VV recombinants expressing the F, NP and M antigens, but not the HA. In contrast, immunization with a VV recombinant expressing the CDV F protein completely protected mice from CDV. PMID:8470428

  4. A recombinant attenuated Salmonella enterica Serovar Typhimurium vaccine encoding Eimeria acervulina antigen offers protection against E. acervulina challenge.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coccidiosis is a ubiquitous disease caused by several distinct species of intestinal protozoan parasite Eimeria spp.. Cell-mediated immunity (CMI) is critically important for protection against Eimeria, thus our approach utilizes bacterial Type Three Secretion System (TTSS) to deliver an antigen di...

  5. Cloning of a Recombinant Plasmid Encoding Thiol-Specific Antioxidant Antigen (TSA) Gene of Leishmania majorand Expression in the Chinese Hamster Ovary Cell Line

    PubMed Central

    Fatemeh, Ghaffarifar; Fatemeh, Tabatabaie; Zohreh, Sharifi; Abdolhosein, Dalimiasl; Mohammad Zahir, Hassan; Mehdi, Mahdavi

    2012-01-01

    Background: TSA (thiol-specific antioxidant antigen) is the immune-dominant antigen of Leishmania major and is considered to be the most promising candidate molecule for a recombinant or DNA vaccine against leishmaniasis. The aim of the present work was to express a plasmid containing the TSA gene in eukaryotic cells. Methods: Genomic DNA was extracted, and the TSA gene was amplified by polymerase chain reaction (PCR). The PCR product was cloned into the pTZ57R/T vector, followed by subcloning into the eukaryotic expression vector pcDNA3 (EcoRI and HindIII sites). The recombinant plasmid was characterised by restriction digest and PCR. Eukaryotic Chinese hamster ovary cells were transfected with the plasmid containing the TSA gene. Expression of the L. major TSA gene was confirmed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis and Western blotting. Results: The plasmid containing the TSA gene was successfully expressed, as demonstrated by a band of 22.1 kDa on Western blots. Conclusion: The plasmid containing the TSA gene can be expressed in a eukaryotic cell line. Thus, the recombinant plasmid may potentially be used as a DNA vaccine in animal models. PMID:22977370

  6. Recombinant DNA encoding a desulfurization biocatalyst

    DOEpatents

    Rambosek, J.; Piddington, C.S.; Kovacevich, B.R.; Young, K.D.; Denome, S.A.

    1994-10-18

    This invention relates to a recombinant DNA molecule containing a gene or genes which encode a biocatalyst capable of desulfurizing a fossil fuel which contains organic sulfur molecules. For example, the present invention encompasses a recombinant DNA molecule containing a gene or genes of a strain of Rhodococcus rhodochrous. 13 figs.

  7. Recombinant DNA encoding a desulfurization biocatalyst

    DOEpatents

    Rambosek, John; Piddington, Chris S.; Kovacevich, Brian R.; Young, Kevin D.; Denome, Sylvia A.

    1994-01-01

    This invention relates to a recombinant DNA molecule containing a gene or genes which encode a biocatalyst capable of desulfurizing a fossil fuel which contains organic sulfur molecules. For example, the present invention encompasses a recombinant DNA molecule containing a gene or genes of a strain of Rhodococcus rhodochrous.

  8. Recombinant hepatitis B triple antigen vaccine: Hepacare.

    PubMed

    Zuckerman, Jane N; Zuckerman, Arie J

    2002-08-01

    Infection with hepatitis B virus is a public health problem throughout the world. Hepatitis B vaccines are now included in national immunization programmes of infants and/or adolescents in 129 countries. Current single antigen vaccines, that are plasma-derived or produced by recombinant DNA technology are highly effective, but between 5-10% or more of healthy immunocompetent subjects do not mount an antihepatitis B surface antibody protective response and others respond poorly (hyporesponders). The inclusion of pre-S1 and -S2 components of hepatitis B surface antigen in addition to the single antigen (triple antigen) in a novel vaccine, Hepacare, Medeva Pharma Plc, Speke, UK, overcomes nonresponsiveness and hyporesponsiveness in a significant number of individuals. The triple antigen is indicated for vaccination of nonresponders (and hyporesponders) to the current single antigen vaccines and for persons who require rapid protection against hepatitis B infection. PMID:12901552

  9. Microbial antigenic variation mediated by homologous DNA recombination.

    PubMed

    Vink, Cornelis; Rudenko, Gloria; Seifert, H Steven

    2012-09-01

    Pathogenic microorganisms employ numerous molecular strategies in order to delay or circumvent recognition by the immune system of their host. One of the most widely used strategies of immune evasion is antigenic variation, in which immunogenic molecules expressed on the surface of a microorganism are continuously modified. As a consequence, the host is forced to constantly adapt its humoral immune response against this pathogen. An antigenic change thus provides the microorganism with an opportunity to persist and/or replicate within the host (population) for an extended period of time or to effectively infect a previously infected host. In most cases, antigenic variation is caused by genetic processes that lead to the modification of the amino acid sequence of a particular antigen or to alterations in the expression of biosynthesis genes that induce changes in the expression of a variant antigen. Here, we will review antigenic variation systems that rely on homologous DNA recombination and that are found in a wide range of cellular, human pathogens, including bacteria (such as Neisseria spp., Borrelia spp., Treponema pallidum, and Mycoplasma spp.), fungi (such as Pneumocystis carinii) and parasites (such as the African trypanosome Trypanosoma brucei). Specifically, the various DNA recombination-based antigenic variation systems will be discussed with a focus on the employed mechanisms of recombination, the DNA substrates, and the enzymatic machinery involved. PMID:22212019

  10. Subdominant Outer Membrane Antigens in Anaplasma marginale: Conservation, Antigenicity, and Protective Capacity Using Recombinant Protein

    PubMed Central

    Ducken, Deirdre R.; Brown, Wendy C.; Alperin, Debra C.; Brayton, Kelly A.; Reif, Kathryn E.; Turse, Joshua E.; Palmer, Guy H.; Noh, Susan M.

    2015-01-01

    Anaplasma marginale is a tick-borne rickettsial pathogen of cattle with a worldwide distribution. Currently a safe and efficacious vaccine is unavailable. Outer membrane protein (OMP) extracts or a defined surface protein complex reproducibly induce protective immunity. However, there are several knowledge gaps limiting progress in vaccine development. First, are these OMPs conserved among the diversity of A. marginale strains circulating in endemic regions? Second, are the most highly conserved outer membrane proteins in the immunogens recognized by immunized and protected animals? Lastly, can this subset of OMPs recognized by antibody from protected vaccinates and conserved among strains recapitulate the protection of outer membrane vaccines? To address the first goal, genes encoding OMPs AM202, AM368, AM854, AM936, AM1041, and AM1096, major subdominant components of the outer membrane, were cloned and sequenced from geographically diverse strains and isolates. AM202, AM936, AM854, and AM1096 share 99.9 to 100% amino acid identity. AM1041 has 97.1 to 100% and AM368 has 98.3 to 99.9% amino acid identity. While all four of the most highly conserved OMPs were recognized by IgG from animals immunized with outer membranes, linked surface protein complexes, or unlinked surface protein complexes and shown to be protected from challenge, the highest titers and consistent recognition among vaccinates were to AM854 and AM936. Consequently, animals were immunized with recombinant AM854 and AM936 and challenged. Recombinant vaccinates and purified outer membrane vaccinates had similar IgG and IgG2 responses to both proteins. However, the recombinant vaccinates developed higher bacteremia after challenge as compared to adjuvant-only controls and outer membrane vaccinates. These results provide the first evidence that vaccination with specific antigens may exacerbate disease. Progressing from the protective capacity of outer membrane formulations to recombinant vaccines

  11. Genetically encoded optical activation of DNA recombination in human cells.

    PubMed

    Luo, J; Arbely, E; Zhang, J; Chou, C; Uprety, R; Chin, J W; Deiters, A

    2016-06-30

    We developed two tightly regulated, light-activated Cre recombinase enzymes through site-specific incorporation of two genetically-encoded photocaged amino acids in human cells. Excellent optical off to on switching of DNA recombination was achieved. Furthermore, we demonstrated precise spatial control of Cre recombinase through patterned illumination. PMID:27277957

  12. DNA secondary structures are associated with recombination in major Plasmodium falciparum variable surface antigen gene families

    PubMed Central

    Sander, Adam F.; Lavstsen, Thomas; Rask, Thomas S.; Lisby, Michael; Salanti, Ali; Fordyce, Sarah L.; Jespersen, Jakob S.; Carter, Richard; Deitsch, Kirk W.; Theander, Thor G.; Pedersen, Anders Gorm; Arnot, David E.

    2014-01-01

    Many bacterial, viral and parasitic pathogens undergo antigenic variation to counter host immune defense mechanisms. In Plasmodium falciparum, the most lethal of human malaria parasites, switching of var gene expression results in alternating expression of the adhesion proteins of the Plasmodium falciparum-erythrocyte membrane protein 1 class on the infected erythrocyte surface. Recombination clearly generates var diversity, but the nature and control of the genetic exchanges involved remain unclear. By experimental and bioinformatic identification of recombination events and genome-wide recombination hotspots in var genes, we show that during the parasite’s sexual stages, ectopic recombination between isogenous var paralogs occurs near low folding free energy DNA 50-mers and that these sequences are heavily concentrated at the boundaries of regions encoding individual Plasmodium falciparum-erythrocyte membrane protein 1 structural domains. The recombinogenic potential of these 50-mers is not parasite-specific because these sequences also induce recombination when transferred to the yeast Saccharomyces cerevisiae. Genetic cross data suggest that DNA secondary structures (DSS) act as inducers of recombination during DNA replication in P. falciparum sexual stages, and that these DSS-regulated genetic exchanges generate functional and diverse P. falciparum adhesion antigens. DSS-induced recombination may represent a common mechanism for optimizing the evolvability of virulence gene families in pathogens. PMID:24253306

  13. Plasmodium knowlesi Sporozoite Antigen: Expression by Infectious Recombinant Vaccinia Virus

    NASA Astrophysics Data System (ADS)

    Smith, Geoffrey L.; Godson, G. Nigel; Nussenzweig, Victor; Nussenzweig, Ruth S.; Barnwell, John; Moss, Bernard

    1984-04-01

    The gene coding for the circumsporozoite antigen of the malaria parasite Plasmodium knowlesi was inserted into the vaccinia virus genome under the control of a defined vaccinia virus promoter. Cells infected with the recombinant virus synthesized polypeptides of 53,000 to 56,000 daltons that reacted with monoclonal antibody against the repeating epitope of the malaria protein. Furthermore, rabbits vaccinated with the recombinant virus produced antibodies that bound specifically to sporozoites. These data provide evidence for expression of a cloned malaria gene in mammalian cells and illustrate the potential of vaccinia virus recombinants as live malaria vaccines.

  14. Identification, expression, and immunogenicity of Kaposi's sarcoma-associated herpesvirus-encoded small viral capsid antigen.

    PubMed Central

    Lin, S F; Sun, R; Heston, L; Gradoville, L; Shedd, D; Haglund, K; Rigsby, M; Miller, G

    1997-01-01

    We describe a recombinant antigen for use in serologic tests for antibodies to Kaposi's sarcoma (KS)-associated herpesvirus (KSHV). The cDNA for a small viral capsid antigen (sVCA) was identified by immunoscreening of a library prepared from the BC-1 body cavity lymphoma cell line induced into KSHV lytic gene expression by sodium butyrate. The cDNA specified a 170-amino-acid peptide with homology to small viral capsid proteins encoded by the BFRF3 gene of Epstein-Barr virus and the ORF65 gene of herpesvirus saimiri. KSHV sVCA was expressed from a 0.85-kb mRNA present late in lytic KSHV replication in BC-1 cells. This transcript was sensitive to phosphonoacetic acid and phosphonoformic acid, inhibitors of herpesvirus DNA replication. KSHV sVCA expressed in mammalian cells or Escherichia coli or translated in vitro was recognized as an antigen by antisera from KS patients. Rabbit antisera raised to KSHV sVCA expressed in E. coli detected a 22-kDa protein in KSHV-infected human B cells. Overexpressed KSHV sVCA purified from E. coli and used as an antigen in immunoblot screening assay did not cross-react with EBV BFRF3. Antibodies to sVCA were present in 89% of 47 human immunodeficiency virus (HIV)-positive patients with KS, in 20% of 54 HIV-positive patients without KS, but in none of 122 other patients including children born to HIV-seropositive mothers and patients with hemophilia, autoimmune disease, or nasopharyngeal carcinoma. Low-titer antibody was detected in three sera from 28 healthy subjects. Antibodies to recombinant sVCA correlate with KS in high-risk populations. Recombinant sVCA can be used to examine the seroepidemiology of infection with KSHV in the general population. PMID:9060668

  15. Enhanced production of recombinant Mycobacterium tuberculosis antigens in Escherichia coli by replacement of low-usage codons.

    PubMed

    Lakey, D L; Voladri, R K; Edwards, K M; Hager, C; Samten, B; Wallis, R S; Barnes, P F; Kernodle, D S

    2000-01-01

    A major obstacle to development of subunit vaccines and diagnostic reagents for tuberculosis is the inability to produce large quantities of these proteins. To test the hypothesis that poor expression of some mycobacterial genes in Escherichia coli is due, in part, to the presence of low-usage E. coli codons, we used site-directed mutagenesis to convert low-usage codons to high-usage codons for the same amino acid in the Mycobacterium tuberculosis genes for antigens 85A and 85B and superoxide dismutase. Replacement of five codons in the wild-type gene for antigen 85B increased recombinant protein production in E. coli 54-fold. The recombinant antigen elicited proliferation and gamma interferon production by lymphocytes from healthy tuberculin reactors and was recognized by monoclonal antibodies to native antigen 85, indicating that the recombinant antigen contained T-cell and B-cell epitopes. Northern blotting demonstrated only a 1.7- to 2.5-fold increase in antigen 85B mRNA, suggesting that the enhanced protein production was due primarily to enhanced efficiency of translation. Codon replacement in the genes encoding antigen 85A and superoxide dismutase yielded four- to sixfold increases in recombinant protein production, suggesting that this strategy may be generally applicable to overexpression of mycobacterial genes in E. coli. PMID:10603393

  16. Antigenic structures stably expressed by recombinant TGEV-derived vectors.

    PubMed

    Becares, Martina; Sanchez, Carlos M; Sola, Isabel; Enjuanes, Luis; Zuñiga, Sonia

    2014-09-01

    Coronaviruses (CoVs) are positive-stranded RNA viruses with potential as immunization vectors, expressing high levels of heterologous genes and eliciting both secretory and systemic immune responses. Nevertheless, its high recombination rate may result in the loss of the full-length foreign gene, limiting their use as vectors. Transmissible gastroenteritis virus (TGEV) was engineered to express porcine reproductive and respiratory syndrome virus (PRRSV) small protein domains, as a strategy to improve heterologous gene stability. After serial passage in tissue cultures, stable expression of small PRRSV protein antigenic domains was achieved. Therefore, size reduction of the heterologous genes inserted in CoV-derived vectors led to the stable expression of antigenic domains. Immunization of piglets with these TGEV vectors led to partial protection against a challenge with a virulent PRRSV strain, as immunized animals showed reduced clinical signs and lung damage. Further improvement of TGEV-derived vectors will require the engineering of vectors with decreased recombination rate. PMID:25108114

  17. DNA Recombination Strategies During Antigenic Variation in the African Trypanosome.

    PubMed

    McCulloch, Richard; Morrison, Liam J; Hall, James P J

    2015-04-01

    Survival of the African trypanosome in its mammalian hosts has led to the evolution of antigenic variation, a process for evasion of adaptive immunity that has independently evolved in many other viral, bacterial and eukaryotic pathogens. The essential features of trypanosome antigenic variation have been understood for many years and comprise a dense, protective Variant Surface Glycoprotein (VSG) coat, which can be changed by recombination-based and transcription-based processes that focus on telomeric VSG gene transcription sites. However, it is only recently that the scale of this process has been truly appreciated. Genome sequencing of Trypanosoma brucei has revealed a massive archive of >1000 VSG genes, the huge majority of which are functionally impaired but are used to generate far greater numbers of VSG coats through segmental gene conversion. This chapter will discuss the implications of such VSG diversity for immune evasion by antigenic variation, and will consider how this expressed diversity can arise, drawing on a growing body of work that has begun to examine the proteins and sequences through which VSG switching is catalyzed. Most studies of trypanosome antigenic variation have focused on T. brucei, the causative agent of human sleeping sickness. Other work has begun to look at antigenic variation in animal-infective trypanosomes, and we will compare the findings that are emerging, as well as consider how antigenic variation relates to the dynamics of host-trypanosome interaction. PMID:26104717

  18. [Autoantibody diagnostics in neurology using native and recombinant antigenic substrates].

    PubMed

    Stöcker, W; Saschenbrecker, S; Rentzsch, K; Komorowski, L; Probst, C

    2013-04-01

    Modern diagnostics for the determination of neurologically relevant autoantibodies are based on indirect immunofluorescence using tissue sections of the hippocampus, cerebellum and other tissues. For monospecific detection human embryonic kidney (HEK) cells transfected with different neurological antigens are used. Biochip mosaics are designed to give a quick overview and contain 20 or more substances positioned next to each other on a reaction field, which are incubated with the serum or cerebrospinal fluid (CSF) sample. Western blots based on cerebellum or hippocampus extracts or line blots containing defined recombinant antigens are used additionally. Initial investigations should always comprise the parallel analysis of all major antineural autoantibodies instead of performing only single parameter tests. Up until a few years ago autoantibodies against intracellular neuronal antigens were mainly investigated. Antibodies against structures of the neural cell surface, however, are much more frequently found, especially those against glutamate receptors (type NMDA). PMID:23568169

  19. The Use of Recombinant 31 kDa Antigens of Trichinella spiralis for Serodiagnosis of Experimental Trichinellosis

    PubMed Central

    WANG, Li; TIAN, Xiang Yu; SUN, Ge Ge; LIU, Ruo Dan; LIU, Li Na; ZHANG, Xi; JIANG, Peng; WANG, Zhong Quan; CUI, Jing

    2015-01-01

    Background: We have previously reported that a 31 kDa protein was screened from the excretory-secretory (ES) proteins of Tichinella spiralis muscle larvae (ML) by immunoproteomics using early infection sera, and the gene encoding a 31 kDa protein from T. spiralis was cloned and expressed in an E. coli expression system. In this study, the recombinant 31 kDa antigens were used for detection of anti-Trichinella antibodies in serum of experimentally infected mice by ELISA. Methods: Anti-Trichinella IgG antibodies in sera of mice infected with Trichinella were assayed by ELISA with recombinant 31 kDa antigens, and its sensitivity and specificity were compared with ELISA with ES antigen. Results: The sensitivity and specificity of ELISA with recombinant antigens was 96.67% (29/30) and 96.87% (62/64), compared with 100% (30/30) and 98.44% (63/64) of ELISA with ES antigens was (P>0.05). In heavily, moderately and lightly infected mice (500, 300 and 100 larvae/mouse), anti-Trichinella antibodies were firstly detected by ELISA with recombinant antigens at 8, 12 and 14 dpi, respectively; then increased rapidly with a detection rate of 100% respectively at 28, 22 and 30 dpi. While the antibodies were firstly detected by ELISA with ES antigens at 10, 8 and 10 dpi, respectively, the antibody positive rate reached 100% at 14, 12 and 22 dpi, respectively. Conclusion: The recombinant 31 kDa antigens of T. spirali had a good sensitivity and specificity for detecting anti-Trichinella antibodies and might be the potential diagnostic antigen for trichinellosis. PMID:26246820

  20. The humoral immune response to recombinant nucleocapsid antigen of canine distemper virus in dogs vaccinated with attenuated distemper virus or DNA encoding the nucleocapsid of wild-type virus.

    PubMed

    Griot-Wenk, M E; Cherpillod, P; Koch, A; Zurbriggen, R; Bruckner, L; Wittek, R; Zurbriggen, A

    2001-06-01

    This study compared the humoral immune response against the nucleocapsid-(N) protein of canine distemper virus (CDV) of dogs vaccinated with a multivalent vaccine against parvo-, adeno-, and parainfluenza virus and leptospira combined with either the attenuated CDV Onderstepoort strain (n = 15) or an expression plasmid containing the N-gene of CDV (n = 30). The vaccinations were applied intramuscularly three times at 2-week intervals beginning at the age of 6 weeks. None of the pre-immune sera recognized the recombinant N-protein, confirming the lack of maternal antibodies at this age. Immunization with DNA vaccine for CDV resulted in positive serum N-specific IgG response. However, their IgG (and IgA) titres were lower than those of CDV-vaccinated dogs. Likewise, DNA-vaccinated dogs did not show an IgM peak. There was no increase in N-specific serum IgE titres in either group. Serum titres to the other multivalent vaccine components were similar in both groups. PMID:11475904

  1. Nucleotide sequence and characterization of peb4A encoding an antigenic protein in Campylobacter jejuni.

    PubMed

    Burucoa, C; Frémaux, C; Pei, Z; Tummuru, M; Blaser, M J; Cenatiempo, Y; Fauchère, J L

    1995-01-01

    The 29-kDa protein PEB4, a major antigen of Campylobacter jejuni, is present in all C. jejuni strains tested and elicits an antibody response in infected patients. By screening a lambda gt11 library of chromosomal DNA fragments of C. jejuni strain 81-176 in Escherichia coli Y1090 cells with antibody raised against purified PEB4, a recombinant phage with a 2-kb insert expressing an immunoreactive protein of 29 kDa was isolated. DNA sequence analysis revealed that the insert contains two complete open reading frames ORF-A and ORF-B. ORF-A (peb4A) encodes a 273-residue protein with a calculated molecular mass of 30,460 daltons. The deduced amino acid sequence, composition and pl of the recombinant mature protein are similar to those determined for purified PEB4. The first 21 residues resemble a signal peptide. Gene bank searches indicated 33.7% identity with protein export protein PrsA of Bacillus subtilis and 23.8% identity with protease maturation protein precursor PrtM of Lactococcus lactis. PCR experiments indicate that peb4A is highly conserved among C. jejuni strains. ORF-B begins 2 bp after the last codon of peb4A and encodes a putative protein of 353 residues with 63.4% identity with E. coli fructose 1,6-biphosphate aldolase. The sequence arrangement suggests that these two genes form an operon. PMID:8525063

  2. Synthetic DNA immunogen encoding hepatitis B core antigen drives immune response in liver.

    PubMed

    Obeng-Adjei, N; Choo, D K; Saini, J; Yan, J; Pankhong, P; Parikh, A; Chu, J S; Weiner, D B

    2012-11-01

    The prevalence of hepatitis B virus (HBV) infection in Asia and sub-Sahara Africa is alarming. With quarter of a billion people chronically infected worldwide and at risk of developing liver cancer, the need for a prophylactic or therapeutic vaccination approach that can effectively induce protective responses against the different genotypes of HBV is more important than ever. Such a strategy will require both the induction of a strong antigen-specific immune response and the subsequent deployment of immune response towards the liver. Here, we assessed the ability of a synthetic DNA vaccine encoding a recombinant consensus plasmid from genotype A through E of the HBV core antigen (HBcAg), to drive immunity in the liver. Intramuscular vaccination induced both strong antigen-specific T cell and high titer antibody responses systematically and in the liver. Furthermore, immunized mice showed strong cytotoxic responses that eliminate adoptively transferred HBV-coated target cells. Importantly, vaccine-induced immune responses provided protection from HBcAg plasmid-based liver transfection in a hydrodynamic liver transfection model. These data provide important insight into the generation of peripheral immune responses that are recruited to the liver-an approach that can be beneficial in the search for vaccines or immune-therapies to liver disease. PMID:23037809

  3. Rapid detection of Yersinia pestis recombinant fraction 1 capsular antigen.

    PubMed

    Tsui, Pei-Yi; Tsai, Hui-Ping; Chiao, Der-Jiang; Liu, Cheng-Che; Shyu, Rong-Hwa

    2015-09-01

    Yersinia pestis, an infectious bacterium that is a causative agent of plague, a disease which has been shown to be one of the most feared in history and which has caused millions of deaths. The capsule-like fraction 1 (F1) antigen expressed by Y. pestis is a known specific marker for the identification of the bacteria; therefore, the detection of F1 is important for Y. pestis recognition. In this study, a rapid, sensitive, and specific technique, the lateral flow assay (LFA), was successfully developed to detect Y. pestis by the recombinant F1 antigen. The assay that utilized an anti-F1 polyclonal antibody (Pab) to identify the bacteria was based on a double-antibody sandwich format on a nitrocellulose membrane. With the LFA method, 50 ng/ml of recombinant F1 protein and 10(5) CFU/mL of Y. pestis could be detected in less than 10 min. This assay also showed no cross-reaction with other Yersinia spp. or with some selected capsule-producing Enterobacteriaceae strains. Furthermore, detection of Y. pestis in simulated samples has been evaluated. The detection sensitivity of Y. pestis in various matrices was 10(5) CFU/mL, which was identical to that in PBS buffer. The results obtained suggest that LFA is an excellent tool for detection of Y. pestis contamination in an environment and hence can be used to monitor plague diseases when they emerge. PMID:25994256

  4. Recombinant exon-encoded resilins for elastomeric biomaterials.

    PubMed

    Qin, Guokui; Rivkin, Amit; Lapidot, Shaul; Hu, Xiao; Preis, Itan; Arinus, Shira B; Dgany, Or; Shoseyov, Oded; Kaplan, David L

    2011-12-01

    Resilin is an elastomeric protein found in specialized regions of the cuticle of most insects, providing outstanding material properties including high resilience and fatigue lifetime for insect flight and jumping needs. Two exons (1 and 3) from the resilin gene in Drosophila melanogaster were cloned and the encoded proteins expressed as soluble products in Escherichia coli. A heat and salt precipitation method was used for efficient purification of the recombinant proteins. The proteins were solution cast from water and formed into rubber-like biomaterials via horseradish peroxidase-mediated cross-linking. Comparative studies of the two proteins expressed from the two different exons were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Circular Dichrosim (CD) for structural features. Little structural organization was found, suggesting structural order was not induced by the enzyme-mediated di-tyrosine cross-links. Atomic Force Microscopy (AFM) was used to study the elastomeric properties of the uncross-linked and cross-linked proteins. The protein from exon 1 exhibited 90% resilience in comparison to 63% for the protein from exon 3, and therefore may be the more critical domain for functional materials to mimic native resilin. Further, the cross-linking of the recombinant exon 1 via the citrate-modified photo-Fenton reaction was explored as an alternative di-tyrosine mediated polymerization method and resulted in both highly elastic and adhesive materials. The citrate-modified photo-Fenton system may be suitable for in vivo applications of resilin biomaterials. PMID:21963157

  5. Recombinant Exon-Encoded Resilins for Elastomeric Biomaterials

    PubMed Central

    Qin, Guokui; Rivkin, Amit; Lapidot, Shaul; Hu, Xiao; Arinus, Shira B.; Dgany, Or; Shoseyov, Oded; Kaplan, David L.

    2011-01-01

    Resilin is an elastomeric protein found in specialized regions of the cuticle of most insects, providing outstanding material properties including high resilience and fatigue lifetime for insect flight and jumping needs. Two exons (1 and 3) from the resilin gene in Drosophila melanogaster were cloned and the encoded proteins expressed as soluble products in Escherichia coli. A heat and salt precipitation method was used for efficient purification of the recombinant proteins. The proteins were solution cast from water and formed into rubber-like biomaterials via horseradish peroxidase-mediated cross-linking. Comparative studies of the two proteins expressed from the two different exons were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Circular Dichrosim (CD) for structural features. Little structural organization was found, suggesting structural order was not induced by the enzyme-mediateed dityrosine cross-links. Atomic Force Microscopy (AFM) was used to study the elastomeric properties of the uncross-linked and cross-linked proteins. The protein from exon 1 exhibited 90% resilience in comparison to 63% for the protein from exon 3, and therefore may be the more critical domain for functional materials to mimic native resilin. Further, the cross-linking of the recombinant exon 1 via the citrate-modified photo-Fenton reaction was explored as an alternative dityrosine mediated polymerization method and resulted in both highly elastic and adhesive materials. The citrate-modified photo-Fenton system may be suitable for in-vivo applications of resilin biomaterials. PMID:21963157

  6. Comparative vaccination of cattle against Boophilus microplus with recombinant antigen Bm86 alone or in combination with recombinant Bm91.

    PubMed

    Willadsen, P; Smith, D; Cobon, G; McKenna, R V

    1996-05-01

    Cattle were vaccinated either with a single recombinant tick antigen, Bm86 or with a combination of two recombinant antigens, Bm86 and Bm91 from the tick Boophilus microplus. In three experiments, the responses of cattle to subsequent challenge with the tick were assessed. The addition of the Bm91 antigen enhanced the efficacy of the vaccination over that with Bm86 alone to a statistically significant degree. Moreover, co-vaccination with two antigens did not impair the response of cattle to the Bm86 antigen. Finally, responses of individual cattle to the two antigens were independent. All of these results may be relevant to the increase in efficacy expected from a dual antigen vaccine. PMID:9229376

  7. Use of recombinant chimeric antigens for the serodiagnosis of Mycoplasma pneumoniae infection.

    PubMed

    Montagnani, F; De Paolis, F; Beghetto, E; Gargano, N

    2010-11-01

    In this paper, we have evaluated the diagnostic utility of three antigenic regions of the Mycoplasma pneumoniae P1, P30, and MPN456 gene products in order to replace the soluble, whole-cell bacterial extract in serological assays. Antigenic regions, being previously identified as B-cell epitopes, were used individually or assembled in a recombinant chimeric antigen by genetic engineering. Paired serum samples from 47 patients with M. pneumoniae infection and from 39 subjects with a clinical picture of atypical pneumonia but without a defined diagnosis of M. pneumoniae infection were included. Immunoglobulin G (IgG) antibodies against epitopes carried by recombinant antigens were measured by performing recombinant enzyme-linked immunosorbent assays (Rec-ELISAs). Rec-ELISA results were compared to those obtained by a commercial assay using the whole-cell Mycoplasma antigen. Our study demonstrates that all IgG Rec-ELISAs using recombinant antigens have better sensitivity with respect to the commercial assay. Furthermore, we show that the use of chimeric antigens improve the performance of the assays. The use of recombinant antigens is effective in distinguishing M. pneumoniae-infected patients from uninfected individuals and shows that immunoassays based on recombinant antigens could provide the basis for standardized commercial tests for the serodiagnosis of M. pneumoniae diseases. PMID:20632053

  8. Prime and boost immunization with influenza and adenovirus encoding the Toxoplasma gondii surface antigen 2 (SAG2) induces strong protective immunity.

    PubMed

    Machado, Alexandre V; Caetano, Bráulia C; Barbosa, Rafael P; Salgado, Ana Paula C; Rabelo, Renata H; Garcia, Cristiana C; Bruna-Romero, Oscar; Escriou, Nicolas; Gazzinelli, Ricardo T

    2010-04-19

    In this work, we explored an original vaccination protocol using recombinant influenza and adenovirus. We constructed recombinant influenza viruses harboring dicistronic NA segments containing the surface antigen 2 (SAG2) from Toxoplasma gondii under control of the duplicated 3' promoter. Recombinant influenza viruses were able to drive the expression of the foreign SAG2 sequence in cell culture and to replicate efficiently both in cell culture and in lungs of infected mice. In addition, mice primed with recombinant influenza virus and boosted with a recombinant adenovirus encoding SAG2 elicited both humoral and cellular immune responses specific for SAG2. Moreover, when immunized animals were challenged with the cystogenic P-Br strain of T. gondii, they displayed up to 85% of reduction in parasite burden. These results demonstrate the potential use of recombinant influenza vectors harboring the dicistronic segments in the development of vaccines against infectious diseases. PMID:20189485

  9. Production of recombinant botulism antigens: a review of expression systems.

    PubMed

    Moreira, G M S G; Cunha, C E P; Salvarani, F M; Gonçalves, L A; Pires, P S; Conceição, F R; Lobato, F C F

    2014-08-01

    Botulism is a paralytic disease caused by intoxication with neurotoxins produced by Clostridium botulinum. Despite their similar mechanism of action, the botulinum neurotoxins (BoNT) are classified in eight serotypes (A to H). As to veterinary medicine, the impact of this disease is essentially economic, since different species of production animals can be affected, especially by BoNT/C and D. In human health, botulism is feared in a possible biological warfare, what would involve mainly the BoNT/A, B, E and F. In both cases, the most effective way to deal with botulism is through prevention, which involves vaccination. However, the current vaccines against this disease have several drawbacks on their process of production and, besides this, can be dangerous to producers since it requires certain level of biosafety. This way, recombinant vaccines have been shown to be a great alternative for the development of vaccines against both animal and human botulism. All BoNTs have a 50-kDa light chain (LC) and a 100-kDa heavy chain (HC). The latter one presents two domains of 50 kDa, called the N-terminal (HN) and C-terminal (HC) halves. Among these regions, the HC alone seem to confer the proper immune response against intoxication. Since innumerous studies describe the expression of these distinct regions using different systems, strategies, and protocols, it is difficult to define the best option for a viable vaccine production. Thereby, the present review describes the problematic of botulism and discusses the main advances for the viable production of vaccines for both human and veterinary medicine using recombinant antigens. PMID:24930432

  10. Evaluation of Recombinant SAG1, SAG2, and SAG3 Antigens for Serodiagnosis of Toxoplasmosis

    PubMed Central

    Khanaliha, Khadijeh; Kazemi, Bahram; Shahriari, Bahador; Bandehpour, Mojgan; Sharifniya, Zarin

    2014-01-01

    Serologic tests are widely accepted for diagnosing Toxoplasma gondii but purification and standardization of antigen needs to be improved. Recently, surface tachyzoite and bradyzoite antigens have become more attractive for this purpose. In this study, diagnostic usefulness of 3 recombinant antigens (SAG1, SAG2, and SAG3) were evaluated, and their efficacy was compared with the available commercial ELISA. The recombinant plasmids were transformed to JM109 strain of Escherichia coli, and the recombinants were expressed and purified. Recombinant SAG1, SAG2, and SAG3 antigens were evaluated using different groups of sera in an ELISA system, and the results were compared to those of a commercial IgG and IgM ELISA kit. The sensitivity and specificity of recombinant surface antigens for detection of anti-Toxoplasma IgG in comparison with commercially available ELISA were as follows: SAG1 (93.6% and 92.9%), SAG2 (100.0% and 89.4%), and SAG3 (95.4% and 91.2%), respectively. A high degree of agreement (96.9%) was observed between recombinant SAG2 and commercial ELISA in terms of detecting IgG anti-Toxoplasma antibodies. P22 had the best performance in detecting anti-Toxoplasma IgM in comparison with the other 2 recombinant antigens. Recombinant SAG1, SAG2, and SAG3 could all be used for diagnosis of IgG-specific antibodies against T. gondii. PMID:24850956

  11. DNA sequence of a gene encoding a BALB/c mouse Ld transplantation antigen.

    PubMed

    Moore, K W; Sher, B T; Sun, Y H; Eakle, K A; Hood, L

    1982-02-01

    The sequence of a gene, denoted 27.5, encoding a transplantation antigen for the BALB/c mouse has been determined. Gene transfer studies and comparison of the translated sequence with the partial amino acid sequence of the Ld transplantation antigen establish that gene 27.5 encodes an Ld polypeptide. A comparison of the gene 27.5 sequence with several complementary DNA sequences suggests that the BALB/c mouse may contain a number of closely related L-like genes. Gene 27.5 has eight exons that correlate with the structural domains of the transplantation antigen. PMID:7058332

  12. Production and cell surface display of recombinant anthrax protective antigen on the surface layer of attenuated Bacillus anthracis.

    PubMed

    Wang, Yan-chun; Yuan, Sheng-ling; Tao, Hao-xia; Wang, Ling-chun; Zhang, Zhao-shan; Liu, Chun-jie

    2015-02-01

    To investigate the surface display of the anthrax protective antigen (PA) on attenuated Bacillus anthracis, a recombinant B. anthracis strain, named AP429 was constructed by integrating into the chromosome a translational fusion harboring the DNA fragments encoding the cell wall-targeting domain of the S-layer protein EA1 and the anthrax PA. Crerecombinase action at the loxP sites excised the antibiotic marker. Western blot analysis, fluorescence-activated cell sorting and immunofluorescence analysis confirmed that PA was successfully expressed on the S-layer of the recombinant antibiotic marker-free strain. Notwithstanding extensive proteolytic degradation of the hybrid protein SLHs-PA, quantitative ELISA revealed that approximately 8.1 × 10(6) molecules of SLHs-PA were gained from each Bacillus cell. Moreover, electron microscopy assay indicated that the typical S-layer structures could be clearly observed from the recombinant strain micrographs. PMID:25504373

  13. Production of a recombinant antibody specific for i blood group antigen, a mesenchymal stem cell marker.

    PubMed

    Hirvonen, Tia; Suila, Heli; Tiitinen, Sari; Natunen, Suvi; Laukkanen, Marja-Leena; Kotovuori, Annika; Reinman, Mirka; Satomaa, Tero; Alfthan, Kaija; Laitinen, Saara; Takkinen, Kristiina; Räbinä, Jarkko; Valmu, Leena

    2013-10-01

    Multipotent mesenchymal stem/stromal cells (MSCs) offer great promise for future regenerative and anti-inflammatory therapies. Panels of functional and phenotypical markers are currently used in characterization of different therapeutic stem cell populations from various sources. The i antigen (linear poly-N-acetyllactosamine) from the Ii blood group system has been suggested as a marker for MSCs derived from umbilical cord blood (UCB). However, there are currently no commercially available antibodies recognizing the i antigen. In the present study, we describe the use of antibody phage display technology to produce recombinant antibodies recognizing a structure from the surface of mesenchymal stem cells. We constructed IgM phage display libraries from the lymphocytes of a donor with an elevated serum anti-i titer. Antibody phage display technology is not dependent on immunization and thus allows the generation of antibodies against poorly immunogenic molecules, such as carbohydrates. Agglutination assays utilizing i antigen-positive red blood cells (RBCs) from UCB revealed six promising single-chain variable fragment (scFv) antibodies, three of which recognized epitopes from the surface of UCB-MSCs in flow cytometric assays. The amino acid sequence of the VH gene segment of B12.2 scFv was highly similar to the VH4.21 gene segment required to encode anti-i specificities. Further characterization of binding properties revealed that the binding of B12.2 hyperphage was inhibited by soluble linear lactosamine oligosaccharide. Based on these findings, we suggest that the B12.2 scFv we have generated is a prominent anti-i antibody that recognizes i antigen on the surface of both UCB-MSCs and RBCs. This binder can thus be utilized in UCB-MSC detection and isolation as well as in blood group serology. PMID:24083089

  14. MAP1272c Encodes an NlpC/P60 Protein, an Antigen Detected in Cattle with Johne's Disease

    PubMed Central

    Lingle, Cari K.; Stabel, Judith R.; Ramyar, Kasra X.; Garcia, Brandon L.; Raeber, Alex J.; Schacher, Pascal; Kapur, Vivek; Geisbrecht, Brian V.

    2012-01-01

    The protein encoded by MAP1272c has been shown to be an antigen of Mycobacterium avium subsp. paratuberculosis that contains an NlpC/P60 superfamily domain found in lipoproteins or integral membrane proteins. Proteins containing this domain have diverse enzymatic functions that include peptidases, amidases, and acetyltransferases. The NlpC protein was examined in comparison to over 100 recombinant proteins and showed the strongest antigenicity when analyzed with sera from cattle with Johne's disease. To further localize the immunogenicity of NlpC, recombinant proteins representing defined regions were expressed and evaluated with sera from cattle with Johne's disease. The region from amino acids 74 to 279 was shown to be the most immunogenic. This fragment was also evaluated against a commercially available enzyme-linked immunosorbent assay (ELISA). Two monoclonal antibodies were produced in mice immunized with the full-length protein, and each recognized a distinct epitope. These antibodies cross-reacted with proteins from other mycobacterial species and demonstrated variable sizes of the proteins expressed from these subspecies. Both antibodies were further analyzed, and their interaction with MAP1272c and MAP1204 was characterized by a solution-based, luminescent binding assay. These tools provide additional means to study a strong antigen of M. avium subsp. paratuberculosis. PMID:22593240

  15. Immunogenicity in dogs of three recombinant antigens (TSA, LeIF and LmSTI1) potential vaccine candidates for canine visceral leishmaniasis.

    PubMed

    Fujiwara, Ricardo Toshio; Vale, André Macedo; França da Silva, João Carlos; da Costa, Roberto Teodoro; Quetz, Josiane da Silva; Martins Filho, Olindo Assis; Reis, Alexandre Barbosa; Corrêa Oliveira, Rodrigo; Machado-Coelho, George Lins; Bueno, Lilian Lacerda; Bethony, Jeffrey Michael; Frank, Glen; Nascimento, Evaldo; Genaro, Odair; Mayrink, Wilson; Reed, Steven; Campos-Neto, Antonio

    2005-01-01

    Control of canine visceral leishmaniasis (VL) remains a difficult and serious problem mostly because there is no reliable and effective vaccine available to prevent this disease. A mixture of three recombinant leishmanial antigens (TSA, LeIF and LmSTI1) encoded by three genes highly conserved in the Leishmania genus have been shown to induce excellent protection against infection in both murine and simian models of cutaneous leishmaniasis. A human clinical trial with these antigens is currently underway. Because of the high degree of conservation, these antigens might be useful vaccine candidates for VL as well. In the present study, using the dog model of the visceral disease, we evaluated the immunogenicity of these three antigens formulated with two different adjuvants, MPL-SE and AdjuPrime. The results were compared with a whole parasite vaccine formulated with BCG as the adjuvant. In order to investigate if sensitization with the recombinant antigens would result in recognition of the corresponding native parasite antigens upon infection, the animals were exposed for four weeks after the termination of the immunization protocol with the recombinant antigens to a low number of L. chagasi promastigotes, an etiological agent of VL. Immune response was evaluated by quantitative ELISA in the animal sera before and after exposure to the viable parasites. Both antigen specific IgG1 and IgG2 antibody levels were measured. Immunization of dogs with the recombinant antigens formulated in either MPL-SE or AdjuPrime resulted in high antibody levels particularly to LmSTI1. In addition, this immunization although to low levels, resulted in the development of antibody response to the whole parasite lysate. Importantly, experimental exposure with low numbers of culture forms of L. chagasi promastigotes caused a clear boost in the immune response to both the recombinant antigens and the corresponding native molecules. The boost response was predominantly of the IgG2 isotype in

  16. Genetic location of genes encoding enterobacterial common antigen.

    PubMed Central

    Meier, U; Mayer, H

    1985-01-01

    A new rff mutation (rff-726) of Escherichia coli is described which affects the biosynthesis of the enterobacterial common antigen. This mutation was detected in an rfe-defective strain. A Tn10 insertion near the rfe locus was isolated to facilitate further mapping. Both mutations rfe and rff were mapped by transduction with bacteriophage P1, giving the gene order ilv rfe rff uvrD metE. The F' factor F14 was able to complement both mutations rfe and rff, whereas the F' factor F16 could complement the rfe but not the rff mutation. The rff mutation did not affect the biosynthesis of N-acetyl-D-mannosaminuronic acid, as the previously described rff mutations in Salmonella typhimurium do (H. C. Lew, H. Nikaido, and P. H. Mäkelä, J. Bacteriol. 136:227-233, 1978), and also did not affect the biosynthesis of other enterobacterial common antigen components; however, the biosynthesis of the complete enterobacterial common antigen molecule was blocked. PMID:3894334

  17. Generation of Antigenic Variants via Gene Conversion: Evidence for Recombination Fitness Selection at the Locus Level in Anaplasma marginale▿

    PubMed Central

    Futse, James E.; Brayton, Kelly A.; Nydam, Seth D.; Palmer, Guy H.

    2009-01-01

    Multiple bacterial and protozoal pathogens utilize gene conversion to generate antigenically variant surface proteins to evade immune clearance and establish persistent infection. Both the donor alleles that encode the variants following recombination into an expression site and the donor loci themselves are under evolutionary selection: the alleles that encode variants that are sufficiently antigenically unique yet retain growth fitness and the loci that allow efficient recombination. We examined allelic usage in generating Anaplasma marginale variants during in vivo infection in the mammalian reservoir host and identified preferential usage of specific alleles in the absence of immune selective pressure, consistent with certain individual alleles having a fitness advantage for in vivo growth. In contrast, the loci themselves appear to have been essentially equally selected for donor function in gene conversion with no significant effect of locus position relative to the expression site or origin of replication. This pattern of preferential allelic usage but lack of locus effect was observed independently for Msp2 and Msp3 variants, both generated by gene conversion. Furthermore, there was no locus effect observed when a single locus contained both msp2 and msp3 alleles in a tail-to-tail orientation flanked by a repeat. These experimental results support the hypothesis that predominance of specific variants reflects in vivo fitness as determined by the encoding allele, independent of locus structure and chromosomal position. Identification of highly fit variants provides targets for vaccines that will prevent the high-level bacteremia associated with acute disease. PMID:19487473

  18. Chimeric Antigens of Toxoplasma gondii: Toward Standardization of Toxoplasmosis Serodiagnosis Using Recombinant Products

    PubMed Central

    Beghetto, Elisa; Spadoni, Andrea; Bruno, Luca; Buffolano, Wilma; Gargano, Nicola

    2006-01-01

    We have evaluated the diagnostic utility of six antigenic regions of the Toxoplasma gondii MIC2, MIC3, M2AP, GRA3, GRA7, and SAG1 gene products, assembled in recombinant chimeric antigens by genetic engineering, in order to replace the soluble, whole-cell tachyzoite extract in serological assays. Serum samples from 100 adults with acquired T. gondii infection and from 30 infants born to mothers with primary toxoplasmosis contracted during pregnancy, of whom 20 were congenitally infected, were included. Immunoglobulin G (IgG) and IgM antibodies against epitopes carried by chimeric antigens were measured by performing parallel enzyme immunoassays (recombinant enzyme-linked immunosorbent assays [Rec-ELISAs]), and the results obtained by standard commercial assays with the whole-cell Toxoplasma antigen and assays with the chimeric antigens were compared. Our results demonstrate that IgG and IgM Rec-ELISAs with individual chimeric antigens have performance characteristics comparable to those of the corresponding commercial assays. Furthermore, we show that IgM-capture assays based on chimeric antigens improve the ability to diagnose congenital toxoplasmosis postnatally compared with the ability to diagnose congenital toxoplasmosis by the use of standard assays. The use of recombinant chimeric antigens is effective in distinguishing T. gondii-infected individuals from T. gondii-uninfected individuals and shows that immunoassays based on recombinant products could provide the basis for standardized commercial tests for the serodiagnosis of toxoplasmosis. PMID:16757610

  19. Immunogenicity of Novel DosR Regulon-Encoded Candidate Antigens of Mycobacterium tuberculosis in Three High-Burden Populations in Africa▿ †

    PubMed Central

    Black, Gillian F.; Thiel, Bonnie A.; Ota, Martin O.; Parida, Shreemanta K.; Adegbola, Richard; Boom, W. Henry; Dockrell, Hazel M.; Franken, Kees L. M. C.; Friggen, Annemiek H.; Hill, Philip C.; Klein, Michel R.; Lalor, Maeve K.; Mayanja, Harriet; Schoolnik, Gary; Stanley, Kim; Weldingh, Karin; Kaufmann, Stefan H. E.; Walzl, Gerhard; Ottenhoff, Tom H. M.

    2009-01-01

    Increasing knowledge about DosR regulon-encoded proteins has led us to produce novel Mycobacterium tuberculosis antigens for immunogenicity testing in human populations in three countries in Africa to which tuberculosis (TB) is endemic. A total of 131 tuberculin skin test-positive and/or ESAT-6/CFP10-positive, human immunodeficiency virus-negative adult household contacts of active pulmonary TB cases from South Africa (n = 56), The Gambia (n = 26), and Uganda (n = 49) were tested for gamma interferon responses to 7 classical and 51 DosR regulon-encoded M. tuberculosis recombinant protein antigens. ESAT-6/CFP10 fusion protein evoked responses in >75% of study participants in all three countries. Of the DosR regulon-encoded antigens tested, Rv1733c was the most commonly recognized by participants from both South Africa and Uganda and the third most commonly recognized antigen in The Gambia. The four most frequently recognized DosR regulon-encoded antigens in Uganda (Rv1733c, Rv0081, Rv1735c, and Rv1737c) included the three most immunogenic antigens in South Africa. In contrast, Rv3131 induced the highest percentage of responders in Gambian contacts (38%), compared to only 3.4% of Ugandan contacts and no South African contacts. Appreciable percentages of TB contacts with a high likelihood of latent M. tuberculosis infection responded to several novel DosR regulon-encoded M. tuberculosis proteins. In addition to significant similarities in antigen recognition profiles between the three African population groups, there were also disparities, which may stem from genetic differences between both pathogen and host populations. Our findings have implications for the selection of potential TB vaccine candidates and for determining biosignatures of latent M. tuberculosis infection, active TB disease, and protective immunity. PMID:19553548

  20. Generation of Recombinant Modified Vaccinia Virus Ankara Encoding VP2, NS1, and VP7 Proteins of Bluetongue Virus.

    PubMed

    Marín-López, Alejandro; Ortego, Javier

    2016-01-01

    Modified Vaccinia Virus Ankara (MVA) is employed widely as an experimental vaccine vector for its lack of replication in mammalian cells and high expression level of foreign/heterologous genes. Recombinant MVAs (rMVAs) are used as platforms for protein production as well as vectors to generate vaccines against a high number of infectious diseases and other pathologies. The portrait of the virus combines desirable elements such as high-level biological safety, the ability to activate appropriate innate immune mediators upon vaccination, and the capacity to deliver substantial amounts of heterologous antigens. Recombinant MVAs encoding proteins of bluetongue virus (BTV), an Orbivirus that infects domestic and wild ruminants transmitted by biting midges of the Culicoides species, are excellent vaccine candidates against this virus. In this chapter we describe the methods for the generation of rMVAs encoding VP2, NS1, and VP7 proteins of bluetongue virus as a model example for orbiviruses. The protocols included cover the cloning of VP2, NS1, and VP7 BTV-4 genes in a transfer plasmid, the construction of recombinant MVAs, the titration of virus working stocks and the protein expression analysis by immunofluorescence and radiolabeling of rMVA infected cells as well as virus purification. PMID:26458834

  1. Redirected cellular cytotoxicity by infection of effector cells with a recombinant vaccinia virus encoding a tumor-specific monoclonal antibody.

    PubMed

    Paul, S; Bizouarne, N; Dott, K; Ruet, L; Dufour, P; Acres, R B; Kieny, M P

    2000-04-01

    Cytotoxicity is an important function of the immune system that results in the destruction of cellular targets by humoral and/or cellular mechanisms. We wanted to assess the possibility of targeting the lytic function of immune cells toward cancer cells, which express the gene coding for a known tumor antigen (Ag) (GA733-2/epithelial cell adhesion molecule), using a viral vector encoding a monoclonal antibody (mAb) specific for said tumor Ag (CO17-1A). To this end, we have constructed recombinant vaccinia viruses expressing the sequences corresponding to mAb CO17-1A, which recognizes a specific Ag (GA733-2) that is present on the surface of most gastrointestinal carcinomas. The recombinant vectors encoding either a secreted or membrane-anchored form of CO17-1A mAb were used to infect effector cells, which were subsequently assessed for their cytotoxic activity. The recombinant viruses were able to infect both granulocyte-macrophage colony-stimulating factor-activated human macrophages and Ag-stimulated murine cytotoxic T lymphocytes. Infected granulocyte-macrophage colony-stimulating factor-activated macrophages were found to be able to kill GA733-2-expressing tumor cells. Likewise, infected cytotoxic T lymphocytes, although conserving their original alloreactivity, gained the capability of killing GA733-2-expressing cancer cells. PMID:10811480

  2. Identification of genes encoding Schistosoma mansoni antigens using an antigenic sequence tag strategy.

    PubMed

    Zouain, C S; Azevedo, V A; Franco, G R; Pena, S D; Goes, A M

    1998-12-01

    Another approach for the identification of genes that code for antigenic products is described using an antigenic sequence tag (AST) strategy. A Schistosoma mansoni adult worm cDNA library was screened with affinity chromatography-purified immunoglobulins from infected human sera and a mild oxidation treatment with sodium periodate. From 1 or both ends of 30 cDNA clones, 30 ASTs were obtained. Of these, 22 were previously known Sm antigens. One clone had matches with entries for other organisms in the databases and 6 had homology with Sm-expressed sequence tags (EST) entries. These clones, together with another 1 that had no significant database matches, were considered new antigenic genes in S. mansoni. The strategy proved to be efficient for the identification of genes that could be used for immunological studies and evaluation as vaccine candidates. PMID:9920341

  3. Population structuring of multi-copy, antigen-encoding genes in Plasmodium falciparum

    PubMed Central

    Artzy-Randrup, Yael; Rorick, Mary M; Day, Karen; Chen, Donald; Dobson, Andrew P; Pascual, Mercedes

    2012-01-01

    The coexistence of multiple independently circulating strains in pathogen populations that undergo sexual recombination is a central question of epidemiology with profound implications for control. An agent-based model is developed that extends earlier ‘strain theory’ by addressing the var gene family of Plasmodium falciparum. The model explicitly considers the extensive diversity of multi-copy genes that undergo antigenic variation via sequential, mutually exclusive expression. It tracks the dynamics of all unique var repertoires in a population of hosts, and shows that even under high levels of sexual recombination, strain competition mediated through cross-immunity structures the parasite population into a subset of coexisting dominant repertoires of var genes whose degree of antigenic overlap depends on transmission intensity. Empirical comparison of patterns of genetic variation at antigenic and neutral sites supports this role for immune selection in structuring parasite diversity. DOI: http://dx.doi.org/10.7554/eLife.00093.001 PMID:23251784

  4. Recombinant K28 antigen in ELISA in the diagnosis of canine visceral leishmaniosis.

    PubMed

    Venturin, G L; Bragato, J P; Silva, K L O; de Lima, V M F

    2015-12-01

    Crude total antigen (CTA) from Leishmania infantum and recombinant antigen K39 (rK39) and recombinant antigen K28 (rK28) were compared using an ELISA for the diagnosis of canine visceral leishmaniosis (CVL). Forty-two blood samples from healthy dogs from a nonendemic area and 80 blood samples from an endemic area for dogs with visceral leishmaniosis (VL), confirmed with positive parasitological tests for Leishmania spp., were used in an ELISA. The parasitological diagnosis was chosen as a gold standard. The ELISA with rK28 antigen showed sensitivity of 100% and specificity of 100%, high agreement with CTA and rK39, indicating that the rK28 antigen is useful for ELISA serological diagnosis of CVL. PMID:26408410

  5. Recombinant Newcastle Disease Virus Expressing a Foreign Viral Antigen Is Attenuated and Highly Immunogenic in Primates

    PubMed Central

    Bukreyev, Alexander; Huang, Zhuhui; Yang, Lijuan; Elankumaran, Subbiah; St. Claire, Marisa; Murphy, Brian R.; Samal, Siba K.; Collins, Peter L.

    2005-01-01

    Paramyxoviruses such as human parainfluenza viruses that bear inserts encoding protective antigens of heterologous viruses can induce an effective immunity against the heterologous viruses in experimental animals. However, vectors based on common human pathogens would be expected to be restricted in replication in the adult human population due to high seroprevalence, an effect that would reduce vector immunogenicity. To address this issue, we evaluated Newcastle disease virus (NDV), an avian paramyxovirus that is serotypically distinct from common human pathogens, as a vaccine vector. Two strains were evaluated: the attenuated vaccine strain LaSota (NDV-LS) that replicates mostly in the chicken respiratory tract and the Beaudette C (NDV-BC) strain of intermediate virulence that produces mild systemic infection in chickens. A recombinant version of each virus was modified by the insertion, between the P and M genes, of a gene cassette encoding the human parainfluenza virus type 3 (HPIV3) hemagglutinin-neuraminidase (HN) protein, a test antigen with considerable historic data. The recombinant viruses were administered to African green monkeys (NDV-BC and NDV-LS) and rhesus monkeys (NDV-BC only) by combined intranasal and intratracheal routes at a dose of 106.5 PFU per site, with a second equivalent dose administered 28 days later. Little or no virus shedding was detected in nose-throat swabs or tracheal lavages following immunization with either strain. In a separate experiment, direct examination of lung tissue confirmed a highly attenuated, restricted pattern of replication by parental NDV-BC. The serum antibody response to the foreign HN protein induced by the first immunization with either NDV vector was somewhat less than that observed following a wild-type HPIV3 infection; however, the titer following the second dose exceeded that observed with HPIV3 infection, even though HPIV3 replicates much more efficiently than NDV in these animals. NDV appears to be a

  6. A recombinant rabies virus encoding two copies of the glycoprotein gene confers protection in dogs against a virulent challenge.

    PubMed

    Liu, Xiaohui; Yang, Youtian; Sun, Zhaojin; Chen, Jing; Ai, Jun; Dun, Can; Fu, Zhen F; Niu, Xuefeng; Guo, Xiaofeng

    2014-01-01

    The rabies virus (RABV) glycoprotein (G) is the principal antigen responsible for the induction of virus neutralizing antibodies (VNA) and is the major modality of protective immunity in animals. A recombinant RABV HEP-Flury strain was generated by reverse genetics to encode two copies of the G-gene (referred to as HEP-dG). The biological properties of HEP-dG were compared to those of the parental virus (HEP-Flury strain). The HEP-dG recombinant virus grew 100 times more efficiently in BHK-21 cell than the parental virus, yet the virulence of the dG recombinant virus in suckling mice was lower than the parental virus. The HEP-dG virus can improve the expression of G-gene mRNA and the G protein and produce more offspring viruses in cells. The amount of G protein revealed a positive relationship with immunogenicity in mice and dogs. The inactivated HEP-dG recombinant virus induced higher levels of VNA and conferred better protection against virulent RABV in mice and dogs than the inactivated parental virus and a commercial vaccine. The protective antibody persisted for at least 12 months. These data demonstrate that the HEP-dG is stable, induces a strong VNA response and confers protective immunity more effectively than the RABV HEP-Flury strain. HEP-dG could be a potential candidate in the development of novel inactivated rabies vaccines. PMID:24498294

  7. Multiple antigens of Yersinia pestis delivered by live recombinant attenuated Salmonella vaccine strains elicit protective immunity against plague.

    PubMed

    Sanapala, Shilpa; Rahav, Hannah; Patel, Hetal; Sun, Wei; Curtiss, Roy

    2016-05-01

    Based on our improved novel Salmonella vaccine delivery platform, we optimized the recombinant attenuated Salmonella typhimurium vaccine (RASV) χ12094 to deliver multiple Yersinia pestis antigens. These included LcrV196 (amino acids, 131-326), Psn encoded on pYA5383 and F1 encoded in the chromosome, their synthesis did not cause adverse effects on bacterial growth. Oral immunization with χ12094(pYA5383) simultaneously stimulated high antibody titers to LcrV, Psn and F1 in mice and presented complete protection against both subcutaneous (s.c.) and intranasal (i.n.) challenges with high lethal doses of Y. pestis CO92. Moreover, no deaths or other disease symptoms were observed in SCID mice orally immunized with χ12094(pYA5383) over a 60-day period. Therefore, the trivalent S. typhimurium-based live vaccine shows promise for a next-generation plague vaccine. PMID:27060051

  8. Expression and T cell recognition of hybrid antigens with amino-terminal domains encoded by Qa-2 region of major histocompatibility complex and carboxyl termini of transplantation antigens.

    PubMed

    Stroynowski, I; Forman, J; Goodenow, R S; Schiffer, S G; McMillan, M; Sharrow, S O; Sachs, D H; Hood, L

    1985-05-01

    Coding potential of the Q6 gene from the Qa-2a region of BALB/c Crgl mice was analyzed by a combination of hybrid class I gene construction and DNA-mediated gene transfer. Recombinant genes were created by exon shuffling of the 5' coding region of the Q6 gene and the 3' coding region of a gene encoding a transplantation antigen (Kd, Dd, or Ld), or the inverse. Some of these hybrid class I genes were expressed in the transfected mouse fibroblasts (L cells). The hybrid class I molecules encoded by the 5' end of the Q6 gene and the 3' end of the Ld gene precipitated as 45,000 mol wt molecules associated with beta 2-microglobulin. The expression of the hybrid proteins indicates that 926 basepairs of the 5' flanking region upstream of the structural Q6 gene contain a promoter that functions as a transcription initiation site in L cells. The 3' portion of the Q6 gene appears to be responsible for the lack of cell surface expression of the intact Q6 and the hybrid Ld/Q6 genes in mouse fibroblasts. Accordingly, this portion of the Q6 class I gene may play a regulatory role in tissue-specific expression. Serological analyses of hybrid Q6 proteins suggested that Q6 may be a structural gene for CR (H-2 crossreactive) antigen found normally on subpopulations of lymphocytes. If this identification is correct, Q6 gene will define a new category of class I genes encoding approximately 40,000 mol wt molecules and carrying a characteristic truncated cytoplasmic tail. Analysis of L cells transfected with Q6 hybrid genes demonstrated also that the cytotoxic T cells specific for Qa-2a region-coded antigens recognize the amino-terminal alpha 1-alpha 2 domain of Q6 fusion products. This recognition can be blocked by anti-Qa-2a alloantiserum and monoclonal antibodies reactive with the alpha 3-beta 2-microglobulin portion of the Q6 hybrids. We propose that the structural requirements for the anti-Qa-2a cytotoxic T lymphocyte-specific epitopes on target molecules are the same as for anti

  9. Improved Serodiagnosis of Cystic Echinococcosis Using the New Recombinant 2B2t Antigen

    PubMed Central

    Hernández-González, Ana; Santivañez, Saúl; García, Héctor H.; Rodríguez, Silvia; Muñoz, Santiago; Ramos, Guillermo; Orduña, Antonio; Siles-Lucas, Mar

    2012-01-01

    A standardized test for the serodiagnosis of human cystic echinococcosis (CE) is still needed, because of the low specificity and sensitivity of the currently available commercial tools and the lack of proper evaluation of the existing recombinant antigens. In a previous work, we defined the new ELISA-B2t diagnostic tool for the detection of specific IgGs in CE patients, which showed high sensitivity and specificity, and was useful in monitoring the clinical evolution of surgically treated CE patients. Nevertheless, this recombinant antigen gave rise to false-negative results in a percentage of CE patients. Therefore, in an attempt to improve its sensitivity, we constructed B2t-derived recombinant antigens with two, four and eight tandem repeat of B2t units, and tested them by ELISA on serum samples of CE patients and patients with related parasites. The best diagnostic values were obtained with the two tandem repeat 2B2t antigen. The influence of several clinical variables on the performance of the tests was also evaluated. Finally, the diagnostic performance of the 2B2t-ELISA was compared with that of an indirect haemagglutination commercial test. The 2B2t recombinant antigen performed better than the HF and B2t antigens, and the IHA commercial kit. Therefore, this new 2B2t-ELISA is a promising candidate test for the serodiagnosis of CE in clinical settings. PMID:22802975

  10. Isolation and characterization of recombinant lambda gt11 bacteriophages expressing eight different mycobacterial antigens of potential immunological relevance.

    PubMed Central

    Andersen, A B; Worsaae, A; Chaparas, S D

    1988-01-01

    A genomic lambda gt11 DNA library of Mycobacterium tuberculosis was screened for expression of mycobacterial protein antigens with murine monoclonal antibodies. The reactivity patterns of the monoclonal antibodies ranged from those showing a limited interspecies reactivity to antibodies widely cross-reactive among different mycobacterial species. Twelve recombinant bacteriophages were isolated, containing eight mycobacterial genes (paa, pab, pac, pad, paeA, paeB, pafA, and pafB) encoding protein antigens. Physical maps of the phages were generated and the products of the recombinant genes were analyzed by immunoblotting techniques. PaeA and PaeB are distinct proteins but were shown to share an epitope. A similar condition was observed between PafA and PafB. Among the phages isolated, two groups expressed epitopes specific for M. tuberculosis and Mycobacterium bovis BCG. One group of phages produced an antigenic determinant which is found in M. tuberculosis and Mycobacterium marinum but not in M. bovis BCG. Images PMID:2451643

  11. Construction of a Novel DNA Vaccine Candidate Encoding an HspX-PPE44-EsxV Fusion Antigen of Mycobacterium tuberculosis

    PubMed Central

    Moradi, Bagher; Sankian, Mojtaba; Amini, Yousef; Meshkat, Zahra

    2016-01-01

    Background: Mycobacterium tuberculosis is the causative agent of tuberculosis (TB). Bacille Calmette-Guerin (BCG) vaccine, is not effective in adults, therefore, many efforts have been made to produce an effective adult TB vaccine. The aim of this study was to develop a new tuberculosis DNA vaccine candidate encoding a recombinant HspX-PPE44-EsxV fusion antigen of M. tuberculosis. Methods: A fusion DNA segment consisting of HspX, linker, PPE44, linker, and EsxV, after codon optimization, was designed. The fusion DNA was cloned and its sequence confirmed. Then, expression of a recombinant pcDNA3.1 (+)/HspX-PPE44-EsxV plasmid in Chinese hamster ovary (CHO) cells was verified by RT-PCR and Western-blot analysis. Results: A 1968 bp band in RT-PCR and a 68 kDa band on Western-blot analysis confirmed transcription and expression of recombinant hspX-ppe44-esxV in eukaryotic cells. Conclusion: A recombinant DNA segment encoding the HspX-PPE44-EsxV fusion antigen of M. tuberculosis was constructed and considered to be tested as a new TB DNA vaccine candidate. PMID:27536702

  12. Development of Recombinant Antigen Array for Simultaneous Detection of Viral Antibodies

    PubMed Central

    Liu, Yi; Yu, Fengling; Huang, Haiyan; Han, Jinxiang

    2013-01-01

    Protein microarrays have been developed to study antibody reactivity against a large number of antigens, demonstrating extensive perspective for clinical application. We developed a viral antigen array by spotting four recombinant antigens and synthetic peptide, including glycoprotein G of herpes simplex virus (HSV) type 1 and 2, phosphoprotein 150 of cytomegalovirus (CMV), Rubella virus (RV) core plus glycoprotein E1 and E2 as well as a E1 peptide with the optimal concentrations on activated glass slides to simultaneously detect IgG and IgM against HSV1, HSV2, CMV and RV in clinical specimens of sera and cerebrospinal fluids (CSFs). The positive reference sera were initially used to measure the sensitivity and specificity of the array with the optimal conditions. Then clinical specimens of 144 sera and 93 CSFs were tested for IgG and IgM antibodies directed against HSV1, HSV2, CMV and RV by the antigen array. Specificity of the antigen array for viral antibodies detection was satisfying compared to commercial ELISA kits but sensitivity of the array varied relying on quality and antigenic epitopes of the spotting antigens. In short, the recombinant antigen array has potential to simultaneous detect multiple viral antibodies using minute amount (3 µl) of samples, which holds the particularly advantage to detect viral antibodies in clinical CSFs being suspicious of neonatal meningitis and encephalitis. PMID:24058498

  13. Mucosal immunization with recombinant adenovirus encoding soluble globular head of hemagglutinin protects mice against lethal influenza virus infection.

    PubMed

    Kim, Joo Young; Choi, Youngjoo; Nguyen, Huan H; Song, Man Ki; Chang, Jun

    2013-12-01

    Influenza virus is one of the major sources of respiratory tract infection. Due to antigenic drift in surface glycoproteins the virus causes annual epidemics with severe morbidity and mortality. Although hemagglutinin (HA) is one of the highly variable surface glycoproteins of the influenza virus, it remains the most attractive target for vaccine development against seasonal influenza infection because antibodies generated against HA provide virus neutralization and subsequent protection against the virus infection. Combination of recombinant adenovirus (rAd) vector-based vaccine and mucosal administration is a promising regimen for safe and effective vaccination against influenza. In this study, we constructed rAd encoding the globular head region of HA from A/Puerto Rico/8/34 virus as vaccine candidate. The rAd vaccine was engineered to express high level of the protein in secreted form. Intranasal or sublingual immunization of mice with the rAd-based vaccine candidates induced significant levels of sustained HA-specific mucosal IgA and IgG. When challenged with lethal dose of homologous virus, the vaccinated mice were completely protected from the infection. The results demonstrate that intranasal or sublingual vaccination with HA-encoding rAd elicits protective immunity against infection with homologous influenza virus. This finding underlines the potential of our recombinant adenovirus-based influenza vaccine candidate for both efficacy and rapid production. PMID:24385946

  14. Isolation and characterization of recombinant lambda gt11 bacteriophages expressing four different Mycobacterium intracellulare antigens.

    PubMed Central

    Morris, S L; Rouse, D A; Hussong, D; Chaparas, S D

    1990-01-01

    Four bacteriophages expressing different immunoreactive recombinant Mycobacterium intracellulare antigens were isolated from a lambda gt11 library with monoclonal antibodies to M. intracellulare. These four antibodies reacted with native M. intracellulare proteins of 54, 43, 40/38, and 22 kilodaltons. Southern blot hybridizations with DNA probes prepared from insert fragments of these bacteriophages confirmed the M. intracellulare derivation of the inserts. The physical maps of the immunoreactive phages were deduced by restriction enzyme digestions. The molecular weights of the expressed recombinant antigens were determined by Western (immuno-) blotting. Images PMID:2136733

  15. Immunogenicity of the recombinant HxuCBA proteins encoded by hxuCBA gene cluster of Haemophilus parasuis in mice.

    PubMed

    Wen, Yiping; Yan, Xuefeng; Wen, Yiping; Cao, Sanjie; He, Lvqin; Ding, Lingqiang; Zhang, Luhua; Zhou, Peng; Huang, Xiaobo; Wu, Rui; Wen, Xintian

    2016-10-15

    Haemophilus parasuis causes serious economic losses in pigs, which is the etiology of Glässer's disease. In this study we studied the immunogenicity of proteins encoded by the hxuCBA gene cluster in H. parasuis. Through bioinformatics analysis, HxuC, HxuB, and HxuA proteins were found that they might have strong antigenicity, with 31 putative cytotoxic T-lymphocyte (CTL) epitopes and multiple B-cell antigenic determinants. Western blotting assay indicated that all these antigens are highly immunogenic. The antibody levels and the levels of IL-2, IL-4, IFN-γ in the groups of HxuA, HxuB, HxuC, HxuCBA (include HxuC, HxuB and HxuA proteins), and M-3 were observed to significantly increase with time post vaccination. HxuC, HxuB, HxuCBA and H. parasuis M-3 vaccinated groups showed a strong immune response and protection against challenge with 6.5×10(9)cfu (5×LD50) of H. parasuis M-3 strain in a mouse model, but HxuA group showed only a low level protection. Additionally, the immune response induced by all of the proteins reduced histopathological lesions and their antisera could inhibit the growth of H. parasuis. We concluded that HxuC, HxuB and HxuCBA may have potential for use as a recombinant subunit vaccine against H. parasuis challenge. PMID:27378742

  16. Genetic analysis of a Treponema phagedenis locus encoding antigenic lipoproteins with potential for antigenic variation.

    PubMed

    Mushtaq, Mamoona; Bongcam-Rudloff, Erik; Loftsdottir, Heidur; Pringle, Märit; Segerman, Bo; Zuerner, Richard; Rosander, Anna

    2016-06-30

    Digital dermatitis (DD) is a painful and debilitating claw disease in cattle. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The occurrence of Treponema phagedenis in DD lesions, especially near the interface of healthy and diseased tissue, suggests that this species contributes to the development and/or progression of the lesions. In this study we characterized a genetic locus in T. phagedenis that contains coding regions for three antigenic proteins, PrrA, VpsA, and VpsB. Comparative analysis of homologous loci from fifteen strains suggests that prrA may be transposed into or out of this locus. Alterations in the copy number of TA repeats within the putative promoter region may regulate VpsA/B expression. The vpsA and prrA genes occur in allelic variants in different T. phagedenis isolates and may provide one explanation for the antigenic variation observed in T. phagedenis DD isolates. PMID:27259832

  17. Murine responses to recombinant MVA versus ALVAC vaccines against tumor-associated antigens, gp100 and 5T4.

    PubMed

    Hanwell, David G; McNeil, Bryan; Visan, Lucian; Rodrigues, Lauren; Dunn, Pamela; Shewen, Patricia E; Macallum, Grace E; Turner, Patricia V; Vogel, Thorsten U

    2013-05-01

    Virally vectored cancer vaccines comprise a new form of immunotherapy that aim to generate anti-tumor immune responses with potential for tumor clearance and enhanced patient survival. Here, we compared 2 replication-deficient poxviruses modified vaccinia Ankara (MVA) and ALVAC(2) in their ability to induce antigen expression and immunogenicity of the tumor-associated antigens (TAAs) 5T4 and gp100. To facilitate the comparison, recombinant MVA-gp100M and ALVAC(2)-5T4 were constructed to complement existing ALVAC(2)-gp100M and MVA-5T4 vectors. Recombinant TAA expression in chicken embryo fibroblast cells was confirmed by Western blot analysis. 5T4 expression was approximately equal for both viruses, whereas ALVAC-derived gp100 was quickly degraded, at a time point when MVA-derived gp100 was still stable and expressed at high levels. Human leukocyte antigen-A2 transgenic mice were vaccinated with recombinant viruses and the CD8 T-cell responses elicited against each TAA were monitored by interferon-γ enzyme-linked immunospot. No 5T4 peptide responses were detected using splenocytes from mice vaccinated with either vector, whereas vaccination with MVA elicited a significantly higher gp100-specific response than ALVAC(2) at 10 PFU (P<0.001). In CD-1 mice, each vector elicited similar 5T4 antibody responses, whereas MVA was more potent and induced gp100 antibody responses at a lower immunization dose than ALVAC (P<0.001). In this study, immunogenicity varied depending on the viral vector used and reflected vector-associated differences in in vitro TAA expression and stability. These findings suggest that novel vector-transgene combinations must be assessed individually when designing vaccines, and that stability of vector-encoded proteins produced in vitro may be useful as a predictor for in vitro immunogenicity. PMID:23603858

  18. The 3' portion of the gene for a Plasmodium yoelii merozoite surface antigen encodes the epitope recognized by a protective monoclonal antibody.

    PubMed Central

    Burns, J M; Daly, T M; Vaidya, A B; Long, C A

    1988-01-01

    The 230-kDa merozoite antigen of the murine malarial parasite Plasmodium yoelii provides a potential model system for the development of a protective erythrocytic stage vaccine. To characterize this antigen at the molecular level, isolated P. yoelii 17XL DNA was used to construct a genomic library in the expression vector lambda gt11. A monoclonal antibody, mAb 302, which passively protected mice against P. yoelii challenge infection, was used to identify a lambda gt11 recombinant clone encoding a portion of the 230-kDa antigen of this parasite. Using this clone as a probe, we identified an mRNA of 7.6 kilobases by RNA blot analysis. Nucleic acid sequence analysis of the clone showed that the epitope recognized by the protective mAb 302 is encoded by the 3' portion of the gene for the 230-kDa antigen. The deduced amino acid sequence revealed that this antigen also contains the tandemly repeated tetrapeptide Gly-Ala-Val-Pro, a series of 10 cysteine residues located within the terminal 110 amino acids, and a potential membrane anchor of 18 hydrophobic residues. Comparison of this C-terminal sequence with the carboxyl segment of the 195-kDa merozoite antigen of Plasmodium falciparum revealed nucleic acid and amino acid sequence similarities ranging from 40% to 70%. The localization of a B-cell epitope recognized by the protective mAb 302 to this carboxyl region of the P. yoelii antigen, combined with the limited strain variability in this region of the homologous 195-kDa antigen of P. falciparum, has implications for the development of an effective erythrocytic stage malarial vaccine. Images PMID:2448778

  19. Serum antibodies to whole-cell and recombinant antigens of Borrelia burgdorferi in cottontail rabbits.

    PubMed

    Magnarelli, Louis A; Norris, Steven J; Fikrig, Erol

    2012-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985-86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, or VlsE) during different seasons, but there was no reactivity to outer surface protein (Osp)A or OspB. Seventy-six of the 102 sera (75%) analyzed were reactive with one or more of the antigens; 61 of the positive samples (80%) reacted to whole-cell antigens, followed by results for the p35 (58%, 44/76), VlsE (43%, 33/76), and p37 (29%, 22/ 76) antigens. Fifty-eight sera (76%) contained antibodies to the VlsE or p35 antigens with or without reactivity to whole-cell antigens. High antibody titers (≥1:2,560) recorded for 52 sera indicate robust antibody production. In analyses for IgM antibodies in an ELISA containing whole-cell antigens, there were 30 positive sera; titers ranged from 1:160 to 1:640. There was minimal cross-reactivity when rabbit antisera to Treponema pallidum or four serovars of Leptospira interrogans were screened against B. burgdorferi antigens. Based on more-specific results, VlsE and p35 antigens appear to be useful markers for detecting possible B. burgdorferi infections. PMID:22247369

  20. SERUM ANTIBODIES TO WHOLE-CELL AND RECOMBINANT ANTIGENS OF BORRELIA BURGDORFERI IN COTTONTAIL RABBITS

    PubMed Central

    Magnarelli, Louis A.; Norris, Steven J.; Fikrig, Erol

    2011-01-01

    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985–86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, or VlsE) during different seasons, but there was no reactivity to outer surface protein (Osp)A or OspB. Seventy-six of the 102 sera (75%) analyzed were reactive with one or more of the antigens; 61 of the positive samples (80%) reacted to whole-cell antigens, followed by results for the p35 (58%, 44/76), VlsE (43%, 33/76), and p37 (29%, 22/76) antigens. Fifty-eight sera (76%) contained antibodies to the VlsE or p35 antigens with or without reactivity to whole-cell antigens. High antibody titers (≥1:2,560) recorded for 52 sera indicate robust antibody production. In analyses for IgM antibodies in an ELISA containing whole-cell antigens, there were 30 positive sera; titers ranged from 1:160 to 1:640. There was minimal cross-reactivity when rabbit antisera to Treponema pallidum or four serovars of Leptospira interrogans were screened against B. burgdorferi antigens. Based on more-specific results, VlsE and p35 antigens appear to be useful markers for detecting possible B. burgdorferi infections. PMID:22247369

  1. Infectious vaccinia virus recombinants that express hepatitis B virus surface antigen

    NASA Astrophysics Data System (ADS)

    Smith, Geoffrey L.; Mackett, Michael; Moss, Bernard

    1983-04-01

    Potential live vaccines against hepatitis B virus have been produced. The coding sequence for hepatitis B virus surface antigen (HBsAg) has been inserted into the vaccinia virus genome under control of vaccinia virus early promoters. Cells infected with these vaccinia virus recombinants synthesize and excrete HBsAg and vaccinated rabbits rapidly produce antibodies to HBsAg.

  2. Overexpression and Enzymatic Assessment of Antigenic Fragments of Hyaluronidase Recombinant Protein From Streptococcus pyogenes

    PubMed Central

    Sadoogh Abbasian, Shabnam; Ghaznavi Rad, Ehsanollah; Akbari, Neda; Zolfaghari, Mohammad Reza; pakzad, Iraj; Abtahi, Hamid

    2014-01-01

    Background: Hyaluronidase catalyzes the hydrolysis of hyaluronan polymers to N-acetyl-D-glucosamine and D-glucuronic acid. This enzyme is a dimer of identical subunits. Hyaluronidase has different pharmaceutical and medical applications. Previously, we produced a recombinant hyaluronidase antigenic fragment of Streptococcus pyogenes. Objectives: This study aimed to improve the protein production and purity of hyaluronidase recombinant protein from S. pyogenes. In addition, the enzymatic activity of this protein was investigated. Materials and Methods: The expression of hyaluronidase antigenic fragments was optimized using IPTG concentration, time of induction, temperature, culture, and absorbance of 0.6-0.8-1 at 600 nm. Afterwards, the expressed proteins were purified and the enzymatic activity was assessed by turbid metric method. Results: Data indicated that maximum protein is produced in OD = 0.8, 0.5 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG), 37ºC, NB 1.5x, without glucose, incubated for overnight. The enzymatic activity of the recombinant protein was similar to the commercial form of hyaluronidase. Conclusions: The results showed that an antigenic fragment of the recombinant hyaluronidase protein from S. pyogenes has a considerable enzymatic activity. It can be suggested to use it for medical purposes. In addition, applications of bioinformatics software would facilitate the production of a smaller protein with same antigenic properties and enzymatic activity. PMID:25789122

  3. A homologue of the recombination-dependent growth gene, rdgC, is involved in gonococcal pilin antigenic variation.

    PubMed Central

    Mehr, I J; Long, C D; Serkin, C D; Seifert, H S

    2000-01-01

    Neisseria gonorrhoeae pilin undergoes high-frequency changes in primary amino acid sequence that aid in the avoidance of the host immune response and alter pilus expression. The pilin amino acid changes reflect nucleotide changes in the expressed gene, pilE, which result from nonreciprocal recombination reactions with numerous silent loci, pilS. A series of mini-transposon insertions affecting pilin antigenic variation were localized to three genes in one region of the Gc chromosome. Mutational analysis with complementation showed that a Gc gene with sequence similarity to the Escherichia coli rdgC gene is involved in pilus-dependent colony phase variation and in pilin antigenic variation. Furthermore, we show that the Gc rdgC homologue is transcriptionally linked in an operon with a gene encoding a predicted GTPase. The inability to disrupt expression of this gene suggests it is an essential gene (engA, essential neisserial GTPase). While some of the transposon mutations in rdgC and insertions in the 5'-untranslated portion of engA showed a growth defect, all transposon insertions investigated conferred an aberrant cellular morphology. Complementation analysis showed that the growth deficiencies are due to the interruption of RdgC expression and not that of EngA. The requirement of RdgC for efficient pilin variation suggests a role for this protein in specialized DNA recombination reactions. PMID:10655208

  4. Several recombinant capsid proteins of equine rhinitis a virus show potential as diagnostic antigens.

    PubMed

    Li, Fan; Stevenson, Rachel A; Crabb, Brendan S; Studdert, Michael J; Hartley, Carol A

    2005-06-01

    Equine rhinitis A virus (ERAV) is a significant pathogen of horses and is also closely related to Foot-and-mouth disease virus (FMDV). Despite these facts, knowledge of the prevalence and importance of ERAV infections remains limited, largely due to the absence of a simple, robust diagnostic assay. In this study, we compared the antigenicities of recombinant full-length and fragmented ERAV capsid proteins expressed in Escherichia coli by using sera from experimentally infected and naturally exposed horses. We found that, from the range of antigens tested, recombinant proteins encompassing the C-terminal region of VP1, full-length VP2, and the N-terminal region of VP2 reacted specifically with antibodies present in sera from each of the five experimentally infected horses examined. Antibodies to epitopes on VP2 (both native and recombinant forms) persisted longer postinfection (>105 days) than antibodies specific for epitopes on other fragments. Our data also suggest that B-cell epitopes within the C terminus of VP1 and N terminus of VP2 contribute to a large proportion of the total reactivity of recombinant VP1 and VP2, respectively. Importantly, the reactivity of these VP1 and VP2 recombinant proteins in enzyme-linked immunosorbent assays (ELISAs) correlated well with the results from a range of native antigen-based serological assays using sera from 12 field horses. This study provides promising candidates for development of a diagnostic ERAV ELISA. PMID:15939754

  5. Relative immunogenicity of hepatitis B virus-encoded antigens as targets for cytotoxic T-cell response.

    PubMed Central

    Ishikawa, T; Kakumu, S; Yoshioka, K; Yamada, M; Tanaka, K; Higashi, Y; Takayanagi, M; Okumura, A; Kojima, A; Tamura, T

    1993-01-01

    To analyse the immunological mechanism of hepatocellular injury in hepatitis B virus (HBV) infection, the immunoreactivity of HBV-encoded antigens as a target for cytotoxic T lymphocyte (CTL) response was examined using recombinant vaccinia virus (RVV) expressing surface protein (S), precore/core protein (PC), and core protein (C) of HBV. C3H/He mice (H-2k) were inoculated with each RVV. Their spleen cells were then harvested and stimulated in vitro with the histocompatible transfectant, which stably expressed hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core antigen (HBcAg), and used as effectors. As the targets, L cells (H-2k) infected with individual RVV were used. Cytotoxic test was performed with various combinations and ratios of effectors and targets. The reactivity of PC-primed effectors against PC-expressing targets was greatest with 71.4% specific lysis on average at an effector/target ratio of 12.5:1 among all the combinations. C-primed effectors against C-expressing target also revealed rather high cytotoxicity (specific lysis, 40.6% at an E/T ratio of 12.5:1). Furthermore, PC-primed and C-primed effectors showed a cross-reactivity to the targets expressing other nucleocapsid antigen, respectively. S-primed effectors showed less lytic activity against S-expressing targets (specific lysis, 18.4% at an E/T ratio of 12.5:1). The CTL responses were blocked by anti-CD8 and anti-major histocompatibility complex (MHC) class I antibodies, but not by anti-CD4 or anti-MHC class II. These findings suggest that endogenously synthesized nucleocapsid antigen, especially PC, is a dominant target for the MHC class I-restricted CTL in H-2k mice and that this system may work as an efficient model to study immunopathogenesis of HBV infection. Images Figure 2 PMID:8262560

  6. Anchoring a secreted plasmodium antigen on the surface of recombinant vaccinia virus-infected cells increases its immunogenicity.

    PubMed Central

    Langford, C J; Edwards, S J; Smith, G L; Mitchell, G F; Moss, B; Kemp, D J; Anders, R F

    1986-01-01

    We show that the subcellular location of foreign antigens expressed in recombinant vaccinia viruses influences their effectiveness as immunogens. Live recombinant viruses induced very poor antibody responses to a secreted repetitive plasmodial antigen (the S-antigen) in rabbits and mice. The poor response accords with epidemiological data suggesting that S-antigens are poorly immunogenic. Appending the transmembrane domain of a membrane immunoglobulin (immunoglobulin G1) to its carboxy terminus produced a hybrid S-antigen that was no longer secreted but was located on the surface of virus-infected cells. This recombinant virus elicited high antibody titers to the S-antigen. This approach will facilitate the use of live virus delivery systems to immunize against a wide range of foreign nonsurface antigens. Images PMID:3537732

  7. Characterization of novel Leishmania infantum recombinant proteins encoded by genes from five families with distinct capacities for serodiagnosis of canine and human visceral leishmaniasis.

    PubMed

    Oliveira, Geraldo G S; Magalhães, Franklin B; Teixeira, Márcia C A; Pereira, Andrea M; Pinheiro, Cristiane G M; Santos, Lenita R; Nascimento, Marília B; Bedor, Cheila N G; Albuquerque, Alessandra L; dos-Santos, Washington L C; Gomes, Yara M; Moreira, Edson D; Brito, Maria E F; Pontes de Carvalho, Lain C; de Melo Neto, Osvaldo P

    2011-12-01

    To expand the available panel of recombinant proteins that can be useful for identifying Leishmania-infected dogs and for diagnosing human visceral leishmaniasis (VL), we selected recombinant antigens from L. infantum, cDNA, and genomic libraries by using pools of serum samples from infected dogs and humans. The selected DNA fragments encoded homologs of a cytoplasmic heat-shock protein 70, a kinesin, a polyubiquitin, and two novel hypothetical proteins. Histidine-tagged recombinant proteins were produced after subcloning these DNA fragments and evaluated by using an enzyme-linked immunosorbent assays with panels of canine and human serum samples. The enzyme-linked immunosorbent assays with different recombinant proteins had different sensitivities (67.4-93.0% and 36.4-97.2%) and specificities (76.1-100% and 90.4-97.3%) when tested with serum samples from Leishmania-infected dogs and human patients with VL. Overall, no single recombinant antigen was sufficient to serodiagnosis all canine or human VL cases. PMID:22144438

  8. Comparative assessment of vaccine vectors encoding ten malaria antigens identifies two protective liver-stage candidates

    PubMed Central

    Longley, Rhea J.; Salman, Ahmed M.; Cottingham, Matthew G.; Ewer, Katie; Janse, Chris J.; Khan, Shahid M.; Spencer, Alexandra J.; Hill, Adrian V. S.

    2015-01-01

    The development of an efficacious Plasmodium falciparum malaria vaccine remains a top priority for global health. Vaccination with irradiated sporozoites is able to provide complete sterile protection through the action of CD8+ T cells at the liver-stage of infection. However, this method is currently unsuitable for large-scale deployment and focus has instead turned to the development of sub-unit vaccines. Sub-unit vaccine efforts have traditionally focused on two well-known pre-erythrocytic antigens, CSP and TRAP, yet thousands of genes are expressed in the liver-stage. We sought to assess the ability of eight alternative P. falciparum pre-erythrocytic antigens to induce a high proportion of CD8+ T cells. We show that all antigens, when expressed individually in the non-replicating viral vectors ChAd63 and MVA, are capable of inducing an immune response in mice. Furthermore, we also developed chimeric P. berghei parasites expressing the cognate P. falciparum antigen to enable assessment of efficacy in mice. Our preliminary results indicate that vectors encoding either PfLSA1 or PfLSAP2 are capable of inducing sterile protection dependent on the presence of CD8+ T cells. This work has identified two promising P. falciparum liver-stage candidate antigens that will now undergo further testing in humans. PMID:26139288

  9. Protection of gerbils from amebic liver abscess by immunization with a recombinant Entamoeba histolytica antigen.

    PubMed Central

    Zhang, T; Cieslak, P R; Stanley, S L

    1994-01-01

    Amebiasis, infection by the intestinal protozoan parasite Entamoeba histolytica, is a leading parasitic cause of death. As a step in the development of a recombinant antigen vaccine to prevent E. histolytica infection, we looked at the ability of a recombinant version of the serine-rich E. histolytica protein (SREHP) to elicit a protective immune response against invasive amebic disease. Gerbils, a standard model for amebic liver abscess, were immunized with either a recombinant SREHP/maltose-binding protein (MBP) fusion, recombinant MBP alone, or phosphate-buffered saline (PBS), all combined with complete Freund's adjuvant. In the first trial (group 1), gerbils received a primary and two booster immunizations intraperitoneally; in the second trial (group 2), gerbils were immunized by a single intradermal injection. SREHP/MBP-immunized gerbils in both groups produced antibody to native SHEHP and developed delayed-type hypersensitivity responses to recombinant SREHP. All gerbils were challenged by an intrahepatic injection with 5 x 10(4) virulent E. histolytica HM1-IMSS trophozoites. Complete protection from amebic liver abscess was seen in 64% of the SHEHP/MBP-immunized gerbils in group 1 and in 100% of the SREHP/MBP-immunized gerbils in group 2. There was no protection observed in MBP- or PBS-immunized gerbils in either group. Our results indicate that the SREHP molecule has potential as a vaccine to prevent amebic infection and demonstrate that successful vaccination of animals with recombinant E. histolytica antigen vaccines is possible. Images PMID:8132322

  10. Modified tumour antigen-encoding mRNA facilitates the analysis of naturally occurring and vaccine-induced CD4 and CD8 T cells in cancer patients.

    PubMed

    Knights, Ashley J; Nuber, Natko; Thomson, Christopher W; de la Rosa, Olga; Jäger, Elke; Tiercy, Jean-Marie; van den Broek, Maries; Pascolo, Steve; Knuth, Alexander; Zippelius, Alfred

    2009-03-01

    The development of effective anti-cancer vaccines requires precise assessment of vaccine-induced immunity. This is often hampered by low ex vivo frequencies of antigen-specific T cells and limited defined epitopes. This study investigates the applicability of modified, in vitro-transcribed mRNA encoding a therapeutically relevant tumour antigen to analyse T cell responses in cancer patients. In this study transfection of antigen presenting cells, by mRNA encoding the tumour antigen NY-ESO-1, was optimised and applied to address spontaneous and vaccine-induced T cell responses in cancer patients. Memory CD8+ T cells from lung cancer patients having detectable humoral immune responses directed towards NY-ESO-1 could be efficiently detected in peripheral blood. Specific T cells utilised a range of different T cell receptors, indicating a polyclonal response. Specific killing of a panel of NY-ESO-1 expressing tumour cell lines indicates recognition restricted to several HLA allelic variants, including a novel HLA-B49 epitope. Using a modified mRNA construct targeting the translated antigen to the secretory pathway, detection of NY-ESO-1-specific CD4+ T cells in patients could be enhanced, which allowed the in-depth characterisation of established T cell clones. Moreover, broad CD8+ and CD4+ T cell responses covering multiple epitopes were detected following mRNA stimulation of patients treated with a recombinant vaccinia/fowlpox NY-ESO-1 vaccine. This approach allows for a precise monitoring of responses to tumour antigens in a setting that addresses the breadth and magnitude of antigen-specific T cell responses, and that is not limited to a particular combination of known epitopes and HLA-restrictions. PMID:18663444

  11. Anionic microparticles are a potent delivery system for recombinant antigens from Neisseria meningitidis serotype B.

    PubMed

    Singh, Manmohan; Kazzaz, Jina; Chesko, James; Soenawan, Elawati; Ugozzoli, Mildred; Giuliani, Marzia; Pizza, Mariagrazia; Rappouli, Rino; O'Hagan, Derek T

    2004-02-01

    The adsorption behavior of model proteins onto anionic poly(lactide-co-glycolide) (PLG) microparticles was evaluated. PLG microparticles were prepared by a w/o/w solvent evaporation process in the presence of the anionic surfactant dioctyl sodium sulfosuccinate (DSS). The effect of surfactant concentration and adsorption conditions on the adsorption efficiency and release rates in vitro was also studied. Subsequently, the microparticle formulation was tested to evaluate the efficacy of anionic microparticles as delivery systems for recombinant antigens from Neisseria meningitides type B (Men B), with and without CpG adjuvant. Protein (antigen) binding to anionic PLG microparticles was influenced by both electrostatic interaction and by other mechanisms, including hydrophobic attraction. The Men B antigens adsorbed efficiently onto anionic PLG microparticles and, following immunization in mice, induced potent enzyme-linked immunosorbent assay (ELISA) and serum bactericidal activity in comparison to alum-adsorbed formulations. These Men B antigens represent an attractive approach for vaccine development. PMID:14705185

  12. Mitotic Evolution of Plasmodium falciparum Shows a Stable Core Genome but Recombination in Antigen Families

    PubMed Central

    Bopp, Selina E. R.; Manary, Micah J.; Bright, A. Taylor; Johnston, Geoffrey L.; Dharia, Neekesh V.; Luna, Fabio L.; McCormack, Susan; Plouffe, David; McNamara, Case W.; Walker, John R.; Fidock, David A.; Denchi, Eros Lazzerini; Winzeler, Elizabeth A.

    2013-01-01

    Malaria parasites elude eradication attempts both within the human host and across nations. At the individual level, parasites evade the host immune responses through antigenic variation. At the global level, parasites escape drug pressure through single nucleotide variants and gene copy amplification events conferring drug resistance. Despite their importance to global health, the rates at which these genomic alterations emerge have not been determined. We studied the complete genomes of different Plasmodium falciparum clones that had been propagated asexually over one year in the presence and absence of drug pressure. A combination of whole-genome microarray analysis and next-generation deep resequencing (totaling 14 terabases) revealed a stable core genome with only 38 novel single nucleotide variants appearing in seventeen evolved clones (avg. 5.4 per clone). In clones exposed to atovaquone, we found cytochrome b mutations as well as an amplification event encompassing the P. falciparum multidrug resistance associated protein (mrp1) on chromosome 1. We observed 18 large-scale (>1 kb on average) deletions of telomere-proximal regions encoding multigene families, involved in immune evasion (9.5×10−6 structural variants per base pair per generation). Six of these deletions were associated with chromosomal crossovers generated during mitosis. We found only minor differences in rates between genetically distinct strains and between parasites cultured in the presence or absence of drug. Using these derived mutation rates for P. falciparum (1.0–9.7×10−9 mutations per base pair per generation), we can now model the frequency at which drug or immune resistance alleles will emerge under a well-defined set of assumptions. Further, the detection of mitotic recombination events in var gene families illustrates how multigene families can arise and change over time in P. falciparum. These results will help improve our understanding of how P. falciparum evolves to

  13. RECOMBINANT SIMIAN VARICELLA VIRUSES EXPRESSING RESPIRATORY SYNCYTIAL VIRUS ANTIGENS ARE IMMUNOGENIC

    PubMed Central

    Ward, Toby M.; Traina-Dorge, Vicki; Davis, Kara A.; Gray, Wayne L.

    2013-01-01

    SUMMARY Recombinant simian varicella viruses (rSVVs) were engineered to express respiratory syncytial virus (RSV) antigens. The RSV surface glycoprotein G and second matrix protein M2 (22k) genes were cloned into the SVV genome, and recombinant viruses were characterized in vitro and in vivo. rSVVs were also engineered to express the membrane-anchored or secreted forms of the RSV G protein as well as an RSV G lacking its chemokine mimicry motif (CX3C), which may have different effects on priming the host immune response. The RSV genes were efficiently expressed in rSVV/RSV infected Vero cells as RSV G and M2 transcripts were detected by RT-PCR and RSV antigens were detected by immunofluorescence and immunoblot assays. The rSVVs replicated efficiently in Vero cell culture. Rhesus macaques immunized with rSVV/RSV-G and rSVV/RSV-M2 vaccines produced antibody responses to SVV and RSV antigens. The results demonstrate that recombinant varicella viruses are suitable vectors for expression of RSV antigens and may represent a novel vaccine strategy for immunization against both pathogens. PMID:18272766

  14. Optimizing Production of Antigens and Fabs in the Context of Generating Recombinant Antibodies to Human Proteins

    PubMed Central

    Zhong, Nan; Loppnau, Peter; Seitova, Alma; Ravichandran, Mani; Fenner, Maria; Jain, Harshika; Bhattacharya, Anandi; Hutchinson, Ashley; Paduch, Marcin; Lu, Vincent; Olszewski, Michal; Kossiakoff, Anthony A.; Dowdell, Evan; Koide, Akiko; Koide, Shohei; Huang, Haiming; Nadeem, Vincent; Sidhu, Sachdev S.; Greenblatt, Jack F.; Marcon, Edyta; Arrowsmith, Cheryl H.; Edwards, Aled M.; Gräslund, Susanne

    2015-01-01

    We developed and optimized a high-throughput project workflow to generate renewable recombinant antibodies to human proteins involved in epigenetic signalling. Three different strategies to produce phage display compatible protein antigens in bacterial systems were compared, and we found that in vivo biotinylation through the use of an Avi tag was the most productive method. Phage display selections were performed on 265 in vivo biotinylated antigen domains. High-affinity Fabs (<20nM) were obtained for 196. We constructed and optimized a new expression vector to produce in vivo biotinylated Fabs in E. coli. This increased average yields up to 10-fold, with an average yield of 4 mg/L. For 118 antigens, we identified Fabs that could immunoprecipitate their full-length endogenous targets from mammalian cell lysates. One Fab for each antigen was converted to a recombinant IgG and produced in mammalian cells, with an average yield of 15 mg/L. In summary, we have optimized each step of the pipeline to produce recombinant antibodies, significantly increasing both efficiency and yield, and also showed that these Fabs and IgGs can be generally useful for chromatin immunoprecipitation (ChIP) protocols. PMID:26437229

  15. Vaccination with a cocktail of Ancylostoma ceylanicum recombinant antigens leads to worm burden reduction in hamsters.

    PubMed

    Wiśniewski, Marcin; Łapiński, Maciej; Daniłowicz-Luebert, Emilia; Jaros, Sławomir; Długosz, Ewa; Wędrychowicz, Halina

    2016-09-01

    Hookworms, a group to which Ancylostoma ceylanicum belongs, are gastrointestinal nematodes that infect more than 700 million people around the world. They are a leading cause of anemia in developing countries. In order to effectively prevent hookworm infections research is conducted to develop an effective vaccine using recombinant antigens of the parasite. The aim of this study was to examine the influence of the hosts' on protection against ancylostomiasis and the shaping of the humoral immune response among Syrian hamsters after immunization with a cocktail of five A. ceylanicum recombinant antigens. Ace-ASP-3, Ace-ASP-4, Ace-APR-1, Ace-MEP-6 and Ace-MEP-7 were obtained in the pET expression system. Immunization with a vaccine cocktail resulted in a 33.5% worm burden reduction. The immunogenicity of the recombinant proteins were determined using ELISA. Statistical analysis showed that vaccinated hamsters developed stronger humoral responses to four of five recombinant antigens (the exception being Ace-ASP-3) compared to hamsters from the control group. PMID:27447220

  16. Recombinant CHIK virus E1 coat protein of 11 KDa with antigenic domains for the detection of Chikungunya.

    PubMed

    Yathi, Krishna Kammara; Joseph, Julia Mary; Bhasker, Salini; Kumar, Ramesh; Chinnamma, Mohankumar

    2011-09-30

    Chikungunya is an acute febrile illness caused by an alpha virus technically called as CHIK virus. A smaller size of CHIK virus E1 coat protein -11 kDa was expressed in prokaryotic expression system. The recombinant protein was purified and confirmed by western blot analysis. The positions of the antigenic domain in the protein were identified and the immunoreactivity of recombinant protein with anti-CHIK IgM antibodies was ascertained. The antigen showed an 88% sensitivity and 100% specificity by Indirect ELISA. No cross reactivity of the antigen was observed with anti-Dengue virus serum samples. The results strongly support that the recombinant CHIK coat protein could be used as a diagnostic antigen for the detection of Chikungunya by Indirect ELISA. The relevance of a smaller size recombinant antigen highlights its large scale application in serodiagnosis of CHIK virus since bacterial expression is more simple and cost effective than eukaryotic system. PMID:21798263

  17. [The lysate and recombinant antigens in ELISA-test-systems for diagnostic of herpes simplex].

    PubMed

    Ganova, L A; Kovtoniuk, G V; Korshun, L N; Kiseleva, E K; Tereshchenko, M I; Vudmaska, M I; Moĭsa, L N; Shevchuk, V A; Spivak, N Ia

    2014-08-01

    The lysate and recombinant antigens of various production included informula of ELISA-test-systems were analyzed. The ELISA-test-systems are used for detection of IgG to Herpes simplex virus type I and II. For testing the panel of serums PTH 201 (BBI Inc.) were used. The samples of this panel contain antibodies to Herpes simplex virus type I and II in mixed titers. The 69 serums of donors were used too (17 samples had IgG to Herpes simplex virus type I, 23 samples to Herpes simplex virus type II and 29 samples had no antibodies to Herpes simplex virus). The diagnostic capacity of mixture of recombinant antigens gG1 Herpes simplex virus type I and gG2 Herpes simplex virus type II (The research-and-production complex "DiaprofMed") was comparable with mixture of lysate antigen Herpes simplex virus type I and II (Membrane) EIE Antigen ("Virion Ltd."). In the test-systems for differentiation of IgG to Herpes simplex virus type I the recombinant antigen gG1 Herpes simplex virus type I proved to be comparable with commercial analogue Herpes simplex virus-1 gG1M ("Viral Therapeutics Inc."'). At the same time, capacity to detect IgG to Herpes simplex virus type II in recombinant protein gG2 Herpes simplex virus type II is significantly higher than in its analogue Herpes simplex virus-2 gG2c ("Viral Therapeutics Inc."). PMID:25552056

  18. High Expression of Water-Soluble Recombinant Antigenic Domains of Toxoplasma gondii Secretory Organelles

    PubMed Central

    Yang, Zhaoshou; Ahn, Hye-Jin

    2014-01-01

    Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with GRA225-105, GRA339-138, ROP2324-561, and MIC21-284 domains had respectively higher value of IgG avidity. The rGST-GRA225-105 and rGST-GRA339-138 were soluble, while rGST-ROP2324-561 and rGST-MIC21-284 were not. GRA231-71, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The rGST-GRA231-71-ROP2324-561, a chimeric protein, appeared to be soluble. Moreover, rGST-GRA231-71-MIC21-284 was also soluble and had higher IgG avidity comparing to rGST-MIC21-284. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1. PMID:25246715

  19. High expression of water-soluble recombinant antigenic domains of Toxoplasma gondii secretory organelles.

    PubMed

    Yang, Zhaoshou; Ahn, Hye-Jin; Nam, Ho-Woo

    2014-08-01

    Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with GRA225-105, GRA339-138, ROP2324-561, and MIC21-284 domains had respectively higher value of IgG avidity. The rGST-GRA225-105 and rGST-GRA339-138 were soluble, while rGST-ROP2324-561 and rGST-MIC21-284 were not. GRA231-71, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The rGST-GRA231-71-ROP2324-561, a chimeric protein, appeared to be soluble. Moreover, rGST-GRA231-71-MIC21-284 was also soluble and had higher IgG avidity comparing to rGST-MIC21-284. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1. PMID:25246715

  20. Successful Interference with Cellular Immune Responses to Immunogenic Proteins Encoded by Recombinant Viral Vectors

    PubMed Central

    Sarukhan, Adelaida; Camugli, Sabine; Gjata, Bernard; von Boehmer, Harald; Danos, Olivier; Jooss, Karin

    2001-01-01

    Vectors derived from the adeno-associated virus (AAV) have been successfully used for the long-term expression of therapeutic genes in animal models and patients. One of the major advantages of these vectors is the absence of deleterious immune responses following gene transfer. However, AAV vectors, when used in vaccination studies, can result in efficient humoral and cellular responses against the transgene product. It is therefore important to understand the factors which influence the establishment of these immune responses in order to design safe and efficient procedures for AAV-based gene therapies. We have compared T-cell activation against a strongly immunogenic protein, the influenza virus hemagglutinin (HA), which is synthesized in skeletal muscle following gene transfer with an adenovirus (Ad) or an AAV vector. In both cases, cellular immune responses resulted in the elimination of transduced muscle fibers within 4 weeks. However, the kinetics of CD4+ T-cell activation were markedly delayed when AAV vectors were used. Upon recombinant Ad (rAd) gene transfer, T cells were activated both by direct transduction of dendritic cells and by cross-presentation of the transgene product, while upon rAAV gene transfer T cells were only activated by the latter mechanism. These results suggested that activation of the immune system by the transgene product following rAAV-mediated gene transfer might be easier to control than that following rAd-mediated gene transfer. Therefore, we tested protocols aimed at interfering with either antigen presentation by blocking the CD40/CD40L pathway or with the T-cell response by inducing transgene-specific tolerance. Long-term expression of the AAV-HA was achieved in both cases, whereas immune responses against Ad-HA could not be prevented. These data clearly underline the importance of understanding the mechanisms by which vector-encoded proteins are recognized by the immune system in order to specifically interfere with them and

  1. Evaluation of two Neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis.

    PubMed

    Lally, N C; Jenkins, M C; Dubey, J P

    1996-05-01

    Neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. Neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. The purpose of this study was to identify N. caninum cDNA clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. Two N. caninum tachyzoite cDNA clones expressing antigens that were recognized by serum from naturally and experimentally infected cattle were identified. The DNA sequences of these clones were determined, and the inserts were subcloned into the plasmid expression vector pTrcHisB. Both recombinant antigens, expressed as fusion proteins with a His6 tag, were purified on a nickel-chelating affinity column and evaluated in separate enzyme-linked immunosorbent assays (ELISAs). Both recombinant antigen ELISAs were capable of distinguishing between sera from Neospora-infected cows and sera from uninfected control cows. Furthermore, both assays were able to detect an antibody response in animals that were experimentally inoculated with N. caninum. Neither antigen showed evidence of cross-reactivity with serum from animals inoculated with the closely related parasites Toxoplasma gondii, Sarcocystis cruzi, Sarcocystis hominis, and Sarcocystis hirsuta. PMID:8705668

  2. Detection of IgG antibody against Crimean-Congo haemorrhagic fever virus using ELISA with recombinant nucleoprotein antigens from genetically diverse strains.

    PubMed

    Rangunwala, A; Samudzi, R R; Burt, F J

    2014-10-01

    Crimean-Congo haemorrhagic fever virus (CCHFV) has the propensity to cause nosocomial infections with a high fatality rate. Handling the virus requires biosafety level-4 facilities, limiting accessibility for many laboratories. Advances in molecular techniques have allowed preparation of safe recombinant antigens that have application in diagnosis and serosurveillance of CCHFV. The aim of this study was to determine genetic diversity in CCHFV based on all available complete sequence data for the S gene encoding CCHFV nucleoprotein (NP) and antibody cross-reactivity between the NP of a South African isolate and the NP of a Greek isolate (AP92), the most genetically diverse CCHFV strain. The nucleotide sequence diversity and amino-acid diversity between genotypes, within genotypes and the pairwise distances were calculated for a dataset of 45 CCHFV isolates retrieved from GenBank. The most diverse virus, AP92, isolated from a tick in Greece, displayed the highest amino-acid difference (8·7%) with SPU415/85, isolated from a human infection in South Africa. Recombinant NP encoded for by codon-optimized S genes of SPU415/85 and AP92 were expressed in a bacterial host system and used to develop an in-house ELISA to detect IgG antibody against CCHFV in South African patients who survived infection. A total of 14/14 sera reacted with the South African recombinant NP and 13/14 reacted with the Greek recombinant NP. The serological cross-reactivity of the two NP antigens suggests that recombinant antigens prepared from geographically distinct CCHFV will have diagnostic and epidemiological applications worldwide. PMID:24330947

  3. A set of recombinant antigens from Echinococcus granulosus with potential for use in the immunodiagnosis of human cystic hydatid disease

    PubMed Central

    VIRGINIO, V G; HERNÁNDEZ, A; ROTT, M B; MONTEIRO, K M; ZANDONAI, A F; NIETO, A; ZAHA, A; FERREIRA, H B

    2003-01-01

    Several recombinant clones expressing antigens from Echinococcus granulosus were isolated previously from a parasite cDNA library using cystic hydatid disease (CHD) patients’ sera or rabbit hyperimmune antiserum against a lipoproteic fraction from bovine cyst fluid. Six of these antigens were expressed in Escherichia coli and the purified recombinant proteins were tested in enzyme-linked immunosorbent assay (ELISA) for specific IgG with a panel of sera from patients with surgically confirmed (n = 58) or immunologically diagnosed (n = 71) CHD. Sera from clinically normal individuals (n = 203) and sera from individuals with other helminthic infections (n = 65) were assayed for the assessment of specificity. A cut-off value was determined by receiver-operating-characteristic plots for each antigen. A recombinant antigen B subunit (AgB8/2) presented the highest sensitivity (93·1%), considering the group of sera from patients with CHD surgically confirmed, and specificity (99·5%) and is proposed as the basis for an immunodiagnostic test. The other recombinant antigens tested presented sensitivities between 58·6% and 89·7%, and three of them were considered of complementary value. In subclass-specific ELISA, different IgG isotypes showed dominance in the response for each of the recombinant antigens. There was a clear predominance of IgG4 response for all antigens tested, indicating that this would be the subclass of choice to be assessed for these recombinant proteins. PMID:12699422

  4. Stable Expression of Lentiviral Antigens by Quality-Controlled Recombinant Mycobacterium bovis BCG Vectors.

    PubMed

    Hart, Bryan E; Asrican, Rose; Lim, So-Yon; Sixsmith, Jaimie D; Lukose, Regy; Souther, Sommer J R; Rayasam, Swati D G; Saelens, Joseph W; Chen, Ching-Ju; Seay, Sarah A; Berney-Meyer, Linda; Magtanong, Leslie; Vermeul, Kim; Pajanirassa, Priyadharshini; Jimenez, Amanda E; Ng, Tony W; Tobin, David M; Porcelli, Steven A; Larsen, Michelle H; Schmitz, Joern E; Haynes, Barton F; Jacobs, William R; Lee, Sunhee; Frothingham, Richard

    2015-07-01

    The well-established safety profile of the tuberculosis vaccine strain, Mycobacterium bovis bacille Calmette-Guérin (BCG), makes it an attractive vehicle for heterologous expression of antigens from clinically relevant pathogens. However, successful generation of recombinant BCG strains possessing consistent insert expression has encountered challenges in stability. Here, we describe a method for the development of large recombinant BCG accession lots which stably express the lentiviral antigens, human immunodeficiency virus (HIV) gp120 and simian immunodeficiency virus (SIV) Gag, using selectable leucine auxotrophic complementation. Successful establishment of vaccine stability stems from stringent quality control criteria which not only screen for highly stable complemented BCG ΔleuCD transformants but also thoroughly characterize postproduction quality. These parameters include consistent production of correctly sized antigen, retention of sequence-pure plasmid DNA, freeze-thaw recovery, enumeration of CFU, and assessment of cellular aggregates. Importantly, these quality assurance procedures were indicative of overall vaccine stability, were predictive for successful antigen expression in subsequent passaging both in vitro and in vivo, and correlated with induction of immune responses in murine models. This study has yielded a quality-controlled BCG ΔleuCD vaccine expressing HIV gp120 that retained stable full-length expression after 10(24)-fold amplification in vitro and following 60 days of growth in mice. A second vaccine lot expressed full-length SIV Gag for >10(68)-fold amplification in vitro and induced potent antigen-specific T cell populations in vaccinated mice. Production of large, well-defined recombinant BCG ΔleuCD lots can allow confidence that vaccine materials for immunogenicity and protection studies are not negatively affected by instability or differences between freshly grown production batches. PMID:25924766

  5. Stable Expression of Lentiviral Antigens by Quality-Controlled Recombinant Mycobacterium bovis BCG Vectors

    PubMed Central

    Hart, Bryan E.; Asrican, Rose; Lim, So-Yon; Sixsmith, Jaimie D.; Lukose, Regy; Souther, Sommer J. R.; Rayasam, Swati D. G.; Saelens, Joseph W.; Chen, Ching-ju; Seay, Sarah A.; Berney-Meyer, Linda; Magtanong, Leslie; Vermeul, Kim; Pajanirassa, Priyadharshini; Jimenez, Amanda E.; Ng, Tony W.; Tobin, David M.; Porcelli, Steven A.; Larsen, Michelle H.; Schmitz, Joern E.; Haynes, Barton F.; Jacobs, William R.; Lee, Sunhee

    2015-01-01

    The well-established safety profile of the tuberculosis vaccine strain, Mycobacterium bovis bacille Calmette-Guérin (BCG), makes it an attractive vehicle for heterologous expression of antigens from clinically relevant pathogens. However, successful generation of recombinant BCG strains possessing consistent insert expression has encountered challenges in stability. Here, we describe a method for the development of large recombinant BCG accession lots which stably express the lentiviral antigens, human immunodeficiency virus (HIV) gp120 and simian immunodeficiency virus (SIV) Gag, using selectable leucine auxotrophic complementation. Successful establishment of vaccine stability stems from stringent quality control criteria which not only screen for highly stable complemented BCG ΔleuCD transformants but also thoroughly characterize postproduction quality. These parameters include consistent production of correctly sized antigen, retention of sequence-pure plasmid DNA, freeze-thaw recovery, enumeration of CFU, and assessment of cellular aggregates. Importantly, these quality assurance procedures were indicative of overall vaccine stability, were predictive for successful antigen expression in subsequent passaging both in vitro and in vivo, and correlated with induction of immune responses in murine models. This study has yielded a quality-controlled BCG ΔleuCD vaccine expressing HIV gp120 that retained stable full-length expression after 1024-fold amplification in vitro and following 60 days of growth in mice. A second vaccine lot expressed full-length SIV Gag for >1068-fold amplification in vitro and induced potent antigen-specific T cell populations in vaccinated mice. Production of large, well-defined recombinant BCG ΔleuCD lots can allow confidence that vaccine materials for immunogenicity and protection studies are not negatively affected by instability or differences between freshly grown production batches. PMID:25924766

  6. A 55-kilodalton antigen encoded by a gene on a Borrelia burgdorferi 49-kilobase plasmid is recognized by antibodies in sera from patients with Lyme disease.

    PubMed Central

    Feng, S; Das, S; Lam, T; Flavell, R A; Fikrig, E

    1995-01-01

    We have identified a 55-kDa antigen encoded by a gene on a 49-kb plasmid of Borrelia burgdorferi. The screening of a B. burgdorferi DNA expression library (N40 strain) with rabbit anti-B. burgdorferi serum and then with serum from a patient with Lyme disease arthritis revealed a clone that synthesized an antigen that was reactive with both sera. DNA sequence analysis identified an operon with two genes, s1 and s2 (1,254 and 780 nucleotides), that expressed antigens with the predicted molecular masses of 55 and 29 kDa, respectively. Pulsed-field gel electrophoresis showed that the s1-s2 operon was located on the 49-kb plasmid. Recombinant S1 was synthesized as a glutathione S-transferase fusion protein in Escherichia coli. Antibodies to recombinant S1 bound to a 55-kDa protein in lysates of B. burgdorferi, indicating that cultured spirochetes synthesized S1. Thirty-one of 100 Lyme disease patients had immunoglobulin G (IgG) and/or IgM antibodies to S1. IgG antibodies to S1 were detected by enzyme-linked immunosorbent assay and immunoblots in the sera of 21 (21%) of 100 patients with Lyme disease; 11 (27.5%) of the S1-positive samples were from patients (40) with early-stage Lyme disease, and 10 (16.7%) were from patients (60) with late-stage Lyme disease. Fifteen (38.5%) of 40 serum samples from patients with early-stage Lyme disease had IgM antibodies to S1. These data suggest that the S1 antigen encoded by a gene on the 49-kb plasmid is recognized serologically by a subset of patients with early- or late-stage Lyme disease. PMID:7642278

  7. Production and immunological characterization of a recombinant subunit of a Loa loa polyprotein antigen.

    PubMed

    Azzibrouck, G Blampain; Akue, J P; Lenoble, D Richard

    2010-06-01

    Diagnosis of loiasis and analysis of the specific immune response are limited by a paucity of parasite material. To circumvent this problem, a Loa loa antigen has been expressed in a prokaryote vector (pTrcHis). Immunization of Balb/c mice with this soluble recombinant protein produced a strong antibody response, with antibodies recognizing 2 major bands of 38 and 20 kDa in a native crude extract of Loa loa adult worms and microfilariae on Western blots. The target molecule was located mainly in the hypodermis and cuticle of the adult worm. Analysis of human IgG subclasses against this antigen by enzyme-linked immunosorbent assay (ELISA) showed IgG1, IgG2 and IgG3 but not IgG4 reactivity. IgG2 against this recombinant antigen was 100% specific for loiasis when tested against samples from European donor individuals. The same IgG2 antibodies showed 91% specificity for loiasis by comparison with Wuchereria bancrofti, Onchocerca volvulus, Mansonnella perstans and other helminth infections. Furthermore, the IgG2 antibody level correlated with the density of Loa loa microfilariae (r=0.400; P=0.02). This recombinant 15r3 molecule and specific IgG2 assay may be useful for monitoring control programmes. PMID:20441677

  8. Recombinant expression and antigenic properties of a 32-kilodalton extracellular alkaline protease, representing a possible virulence factor from Aspergillus fumigatus.

    PubMed Central

    Moser, M; Menz, G; Blaser, K; Crameri, R

    1994-01-01

    A 32-kDa nonglycosylated alkaline protease (EC 3.4.1.14) with elastolytic activity, secreted by the opportunistic pathogen Aspergillus fumigatus ATCC 42202, is suggested to be a virulence factor of this fungus. The enzyme is a serine protease of the subtilisin family, and its cDNA nucleotide sequence has recently been reported. We have cloned the cDNA encoding the mature protease into a high-level Escherichia coli expression plasmid and produced the recombinant protease as a fusion protein with a six-adjacent-histidine affinity tag at the carboxy terminus. Subsequently, the recombinant protease was purified to homogeneity, with affinity chromatography yielding 30 to 40 mg of recombinant protease per liter of E. coli culture. Refolded recombinant protease, in comparison with native protease, demonstrated weak enzymatic activity but similar immunochemical characteristics as analyzed by antigen-specific enzyme-linked immunosorbent assay (ELISA), competition ELISA, and immunoblotting assays. To assess the allergenic potential of the protease, sera from patients with allergic bronchopulmonary aspergillosis and sera from healthy control individuals were analyzed by ELISA and immunoblotting techniques. Sera from patients with allergic bronchopulmonary aspergillosis did not have protease-specific immunoglobulin E (IgE) antibodies and, remarkably, did not show significantly elevated protease-specific IgG antibody levels compared with those in sera from healthy control individuals. This suggests that the alkaline protease from A. fumigatus does not elicit IgE antibodies and has weak immunogenicity, a property which may explain fungus persistence in allergic individuals. Images PMID:8112866

  9. Evaluation of a Recombinant Trypanosoma cruzi Mucin-Like Antigen for Serodiagnosis of Chagas' Disease ▿

    PubMed Central

    De Marchi, Claudia R.; Di Noia, Javier M.; Frasch, Alberto C. C.; Amato Neto, Vicente; Almeida, Igor C.; Buscaglia, Carlos A.

    2011-01-01

    Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and is one of the most important endemic problems in Latin America. Lately, it has also become a health concern in the United States and Europe. Currently, a diagnosis of Chagas' disease and the screening of blood supplies for antiparasite antibodies are achieved by conventional serological tests that show substantial variation in the reproducibility and reliability of their results. In addition, the specificity of these assays is curtailed by antigenic cross-reactivity with sera from patients affected by other endemic diseases, such as leishmaniasis. Here we used a highly sensitive chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) to evaluate a recombinant protein core of a mucin-like molecule (termed trypomastigote small surface antigen [TSSA]) for the detection of specific serum antibodies in a broad panel of human sera. The same samples were evaluated by CL-ELISA using as the antigen either a mixture of native T. cruzi trypomastigote mucins or an epimastigote extract and, for further comparison, by conventional serologic tests, such as an indirect hemagglutination assay and indirect immunofluorescence assay. TSSA showed ∼87% sensitivity among the seropositive Chagasic panel, a value which was increased up to >98% when only parasitologically positive samples were considered. More importantly, TSSA showed a significant increase in specificity (97.4%) compared to those of currently used assays, which averaged 80 to 90%. Overall, our data demonstrate that recombinant TSSA may be a useful antigen for the immunodiagnosis of Chagas' disease. PMID:21880857

  10. Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs.

    PubMed

    Miura, Ryuichi; Kooriyama, Takanori; Yoneda, Misako; Takenaka, Akiko; Doki, Miho; Goto, Yasuyuki; Sanjoba, Chizu; Endo, Yasuyuki; Fujiyuki, Tomoko; Sugai, Akihiro; Tsukiyama-Kohara, Kyoko; Matsumoto, Yoshitsugu; Sato, Hiroki; Kai, Chieko

    2015-01-01

    Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV-LACK, rCDV-TSA, and rCDV-LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV-LACK showed markedly smaller nodules without ulceration. Although the rCDV-TSA- and rCDV-LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV-LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs. PMID:26162094

  11. Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs

    PubMed Central

    Yoneda, Misako; Takenaka, Akiko; Doki, Miho; Goto, Yasuyuki; Sanjoba, Chizu; Endo, Yasuyuki; Fujiyuki, Tomoko; Sugai, Akihiro; Tsukiyama-Kohara, Kyoko; Matsumoto, Yoshitsugu; Sato, Hiroki; Kai, Chieko

    2015-01-01

    Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV–LACK, rCDV–TSA, and rCDV–LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV–LACK showed markedly smaller nodules without ulceration. Although the rCDV–TSA- and rCDV–LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV–LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs. PMID:26162094

  12. An Automated ELISA Using Recombinant Antigens for Serologic Diagnosis of B Virus Infections in Macaques

    PubMed Central

    Katz, David; Shi, Wei; Patrusheva, Irina; Perelygina, Ludmila; Gowda, Manjunath S; Krug, Peter W; Filfili, Chadi N; Ward, John A; Hilliard, Julia K

    2012-01-01

    B virus (Macacine herpesvirus 1) occurs naturally in macaques and can cause lethal zoonotic infections in humans. Detection of B virus (BV) antibodies in macaques is essential for the development of SPF breeding colonies and for diagnosing infection in macaques that are involved in human exposures. Traditionally, BV infections are monitored for presence of antibodies by ELISA (a screening assay) and western blot analysis (WBA; a confirmatory test). Both tests use lysates of infected cells as antigens. Because WBA often fails to confirm the presence of low-titer serum antibodies detected by ELISA, we examined a recombinant-based ELISA as a potential alternative confirmatory test. We compared a high-throughput ELISA using 384-well plates for simultaneous antibody screening against 4 BV-related, recombinant proteins with the standard ELISA and WBA. The recombinant ELISA results confirmed more ELISA-positive sera than did WBA. The superiority of the recombinant ELISA over WBA was particularly prominent for sera with low (<500 ELISA units) antibody titers. Among low-titer sera, the relative sensitivity of the recombinant ELISA ranged from 36.7% to 45.0% as compared with 3.3% to 10.0% for WBA. In addition, the screening and confirmatory assays can be run simultaneously, providing results more rapidly. We conclude that the recombinant ELISA is an effective replacement for WBA as a confirmatory assay for the evaluation of macaque serum antibodies to BV. PMID:23561887

  13. Vaccination against Anthrax with Attenuated Recombinant Strains of Bacillus anthracis That Produce Protective Antigen

    PubMed Central

    Barnard, John P.; Friedlander, Arthur M.

    1999-01-01

    The protective efficacy of several live, recombinant anthrax vaccines given in a single-dose regimen was assessed with Hartley guinea pigs. These live vaccines were created by transforming ΔANR and ΔSterne, two nonencapsulated, nontoxinogenic strains of Bacillus anthracis, with four different recombinant plasmids that express the anthrax protective antigen (PA) protein to various degrees. This enabled us to assess the effect of the chromosomal background of the strain, as well as the amount of PA produced, on protective efficacy. There were no significant strain-related effects on PA production in vitro, plasmid stability in vivo, survival of the immunizing strain in the host, or protective efficacy of the immunizing infection. The protective efficacy of the live, recombinant anthrax vaccine strains correlated with the anti-PA antibody titers they elicited in vivo and the level of PA they produced in vitro. PMID:9916059

  14. Role of recombination activating genes in the generation of antigen receptor diversity and beyond.

    PubMed

    Nishana, Mayilaadumveettil; Raghavan, Sathees C

    2012-12-01

    V(D)J recombination is the process by which antibody and T-cell receptor diversity is attained. During this process, antigen receptor gene segments are cleaved and rejoined by non-homologous DNA end joining for the generation of combinatorial diversity. The major players of the initial process of cleavage are the proteins known as RAG1 (recombination activating gene 1) and RAG2. In this review, we discuss the physiological function of RAGs as a sequence-specific nuclease and its pathological role as a structure-specific nuclease. The first part of the review discusses the basic mechanism of V(D)J recombination, and the last part focuses on how the RAG complex functions as a sequence-specific and structure-specific nuclease. It also deals with the off-target cleavage of RAGs and its implications in genomic instability. PMID:23039142

  15. Clinical and Parasitological Protection in a Leishmania infantum-Macaque Model Vaccinated with Adenovirus and the Recombinant A2 Antigen

    PubMed Central

    Grimaldi, Gabriel; Teva, Antonio; Porrozzi, Renato; Pinto, Marcelo A.; Marchevsky, Renato S.; Rocha, Maria Gabrielle L.; Dutra, Miriam S.; Bruña-Romero, Oscar; Fernandes, Ana-Paula; Gazzinelli, Ricardo T.

    2014-01-01

    Background Visceral leishmaniasis (VL) is a severe vector-born disease of humans and dogs caused by Leishmania donovani complex parasites. Approximately 0.2 to 0.4 million new human VL cases occur annually worldwide. In the new world, these alarming numbers are primarily due to the impracticality of current control methods based on vector reduction and dog euthanasia. Thus, a prophylactic vaccine appears to be essential for VL control. The current efforts to develop an efficacious vaccine include the use of animal models that are as close to human VL. We have previously reported a L. infantum-macaque infection model that is reliable to determine which vaccine candidates are most worthy for further development. Among the few amastigote antigens tested so far, one of specific interest is the recombinant A2 (rA2) protein that protects against experimental L. infantum infections in mice and dogs. Methodology/Principal Findings Primates were vaccinated using three rA2-based prime-boost immunization regimes: three doses of rA2 plus recombinant human interleukin-12 (rhIL-12) adsorbed in alum (rA2/rhIL-12/alum); two doses of non-replicative adenovirus recombinant vector encoding A2 (Ad5-A2) followed by two boosts with rA2/rhIL-12/alum (Ad5-A2+rA2/rhIL12/alum); and plasmid DNA encoding A2 gene (DNA-A2) boosted with two doses of Ad5-A2 (DNA-A2+Ad5-A2). Primates received a subsequent infectious challenge with L. infantum. Vaccines, apart from being safe, were immunogenic as animals responded with increased pre-challenge production of anti-A2-specific IgG antibodies, though with some variability in the response, depending on the vaccine formulation/protocol. The relative parasite load in the liver was significantly lower in immunized macaques as compared to controls. Protection correlated with hepatic granuloma resolution, and reduction of clinical symptoms, particularly when primates were vaccinated with the Ad5-A2+rA2/rhIL12/alum protocol. Conclusions/Significance The

  16. MP1 encodes an abundant and highly antigenic cell wall mannoprotein in the pathogenic fungus Penicillium marneffei.

    PubMed

    Cao, L; Chan, C M; Lee, C; Wong, S S; Yuen, K Y

    1998-03-01

    We cloned the MP1 gene, which encodes an abundant antigenic cell wall mannoprotein from the dimorphic pathogenic fungus Penicillium marneffei. MP1 is a unique gene without homologs in sequence databases. It codes for a protein, Mp1p, of 462 amino acid residues, with a few sequence features that are present in several cell wall proteins of Saccharomyces cerevisiae and Candida albicans. It contains two putative N glycosylation sites, a serine- and threonine-rich region for O glycosylation, a signal peptide, and a putative glycosylphosphatidylinositol attachment signal sequence. Specific anti-Mp1p antibody was generated with recombinant Mp1p protein purified from Escherichia coli to allow further characterization of Mp1p. Western blot analysis with anti-Mp1p antibody revealed that Mp1p has predominant bands with molecular masses of 58 and 90 kDa and that it belongs to a group of cell wall proteins that can be readily removed from yeast cell surfaces by glucanase digestion. In addition, Mp1p is an abundant yeast glycoprotein and has high affinity for concanavalin A, a characteristic indicative of a mannoprotein. Furthermore, ultrastructural analysis with immunogold staining indicated that Mp1p is present in the cell walls of the yeast, hyphae, and conidia of P. marneffei. Finally, it was observed that infected patients develop a specific antibody response against Mp1p, suggesting that this protein represents a good cell surface target for host humoral immunity. PMID:9488383

  17. Polymorphism in the gene encoding the apical membrane antigen-1 (AMA-1) of Plasmodium falciparum. X. Asembo Bay Cohort Project.

    PubMed

    Escalante, A A; Grebert, H M; Chaiyaroj, S C; Magris, M; Biswas, S; Nahlen, B L; Lal, A A

    2001-04-01

    We have investigated the genetic diversity of the gene encoding the apical membrane antigen-1 (AMA-1) in natural populations of Plasmodium falciparum from western Kenya and compared it with parasite populations from other geographic regions. A total of 28 complete sequences from Kenya, Thailand, India, and Venezuela field isolates were obtained. The genetic polymorphism is not evenly distributed across the gene, which is in agreement with the pattern reported in earlier studies. The alleles from Kenya exhibit 20 and 30% more polymorphism than that found in Southeast Asia and Venezuelan alleles, respectively. Based on the gene genealogies derived from sequencing data, no evidence for allele families was found. We have found evidence supporting limited gene flow between the parasite populations, specifically, between the Southeast Asian and Venezuelan isolates; however, no alleles could be linked to a specific geographic region. This study reveals that positive natural selection is an important factor in the maintenance of genetic diversity for AMA-1. We did not find conclusive evidence indicating intragenic recombination is important in the generation of the AMA-1 allelic diversity. The study provides information on the genetic diversity of the AMA-1 gene that would be useful in vaccine development and testing, as well as in assessing factors that are involved in the generation and maintenance of the genetic diversity in P. falciparum. PMID:11295182

  18. Antigen I/II encoded by integrative and conjugative elements of Streptococcus agalactiae and role in biofilm formation.

    PubMed

    Chuzeville, Sarah; Dramsi, Shaynoor; Madec, Jean-Yves; Haenni, Marisa; Payot, Sophie

    2015-11-01

    Streptococcus agalactiae (i.e. Group B streptococcus, GBS) is a major human and animal pathogen. Genes encoding putative surface proteins and in particular an antigen I/II have been identified on Integrative and Conjugative Elements (ICEs) found in GBS. Antigens I/II are multimodal adhesins promoting colonization of the oral cavity by streptococci such as Streptococcus gordonii and Streptococcus mutans. The prevalence and diversity of antigens I/II in GBS were studied by a bioinformatic analysis. It revealed that antigens I/II, which are acquired by horizontal transfer via ICEs, exhibit diversity and are widespread in GBS, in particular in the serotype Ia/ST23 invasive strains. This study aimed at characterizing the impact on GBS biology of proteins encoded by a previously characterized ICE of S. agalactiae (ICE_515_tRNA(Lys)). The production and surface exposition of the antigen I/II encoded by this ICE was examined using RT-PCR and immunoblotting experiments. Surface proteins of ICE_515_tRNA(Lys) were found to contribute to GBS biofilm formation and to fibrinogen binding. Contribution of antigen I/II encoded by SAL_2056 to biofilm formation was also demonstrated. These results highlight the potential for ICEs to spread microbial adhesins between species. PMID:26232503

  19. Antigen-capture blocking enzyme-linked immunosorbent assay based on a baculovirus recombinant antigen to differentiate Transmissible gastroenteritis virus from Porcine respiratory coronavirus antibodies.

    PubMed

    López, Lissett; Venteo, Angel; García, Marga; Camuñas, Ana; Ranz, Ana; García, Julia; Sarraseca, Javier; Anaya, Carmen; Rueda, Paloma

    2009-09-01

    A new commercially available antigen-capture, blocking enzyme-linked immunosorbent assay (antigen-capture b-ELISA), based on baculovirus truncated-S recombinant protein of Transmissible gastroenteritis virus (TGEV) and 3 specific monoclonal antibodies, was developed and evaluated by examining a panel of 453 positive Porcine respiratory coronavirus (PRCoV), 31 positive TGEV, and 126 negative field sera by using another commercially available differential coronavirus b-ELISA as the reference technique to differentiate TGEV- from PRCoV-induced antibodies. The recombinant S protein-based ELISA appeared to be 100% sensitive for TGEV and PRCoV detection and highly specific for TGEV and PRCoV detection (100% and 92.06%, respectively), when qualitative results (positive or negative) were compared with those of the reference technique. In variability experiments, the ELISA gave consistent results when the same serum was evaluated on different wells and different plates. These results indicated that truncated recombinant S protein is a suitable alternative to the complete virus as antigen in ELISA assays. The use of recombinant S protein as antigen offers great advantages because it is an easy-to-produce, easy-to-standardize, noninfectious antigen that does not require further purification or concentration. Those advantages represent an important improvement for antigen preparation, in comparison with other assays in which an inactivated virus from mammalian cell cultures is used. PMID:19737754

  20. Isolation and characterization of cDNA encoding the antigenic protein of the human tRNP(Ser)Sec complex recognized by autoantibodies from patients with type-1 autoimmune hepatitis

    PubMed Central

    Costa, M; Rodríguez-Sánchez, J L; Czaja, A J; Gelpí, C

    2000-01-01

    We previously described autoantibodies against a UGA serine tRNA–protein complex (tRNP(Ser)Sec) in patients with type-1 autoimmune hepatitis [1] and now define the specificity and frequency of this autoantibody and the DNA sequence encoding the tRNA(Ser)Sec-associated antigenic protein. The presence of anti‐tRNP(Ser)Sec antibodies was highly specific for type-1 autoimmune hepatitis, as 47·5% of patients were positive compared with none of the control subjects. To characterize the antigenic protein(s), we immunoscreened a human cDNA library with anti-tRNP(Ser)Sec-positive sera. Two clones (19 and 13) were isolated. Clone 19 encodes a protein with a predicted molecular mass of 48·8 kD. Clone 13 is a shorter cDNA, almost identical to clone 19, which encodes a 35·9-kD protein. Expression of both cDNAs was accomplished in Escherichia coli as His-tagged recombinant proteins. Antibodies eluted from both purified recombinant proteins were able to immunoprecipitate the tRNA(Ser)Sec from a HeLa S3 cell extract, demonstrating their cross-reactivity with the mammalian antigenic complex. Recent cloning data relating to the target antigen(s) of autoantibodies in autoimmune hepatitis patients that react with a soluble liver antigen (SLA) and a liver-pancreas antigen (LP) have revealed that these two autoantibodies are identical and that the cloned antigen shows 99% amino acid sequence homology with tRNP(Ser)Sec. PMID:10931155

  1. Clinical Assessment of a Novel Recombinant Simian Adenovirus ChAdOx1 as a Vectored Vaccine Expressing Conserved Influenza A Antigens

    PubMed Central

    Antrobus, Richard D; Coughlan, Lynda; Berthoud, Tamara K; Dicks, Matthew D; Hill, Adrian VS; Lambe, Teresa; Gilbert, Sarah C

    2014-01-01

    Adenoviruses are potent vectors for inducing and boosting cellular immunity to encoded recombinant antigens. However, the widespread seroprevalence of neutralizing antibodies to common human adenovirus serotypes limits their use. Simian adenoviruses do not suffer from the same drawbacks. We have constructed a replication-deficient chimpanzee adenovirus-vectored vaccine expressing the conserved influenza antigens, nucleoprotein (NP), and matrix protein 1 (M1). Here, we report safety and T-cell immunogenicity following vaccination with this novel recombinant simian adenovirus, ChAdOx1 NP+M1, in a first in human dose-escalation study using a 3+3 study design, followed by boosting with modified vaccinia virus Ankara expressing the same antigens in some volunteers. We demonstrate ChAdOx1 NP+M1 to be safe and immunogenic. ChAdOx1 is a promising vaccine vector that could be used to deliver vaccine antigens where strong cellular immune responses are required for protection. PMID:24374965

  2. Clinical assessment of a novel recombinant simian adenovirus ChAdOx1 as a vectored vaccine expressing conserved Influenza A antigens.

    PubMed

    Antrobus, Richard D; Coughlan, Lynda; Berthoud, Tamara K; Dicks, Matthew D; Hill, Adrian Vs; Lambe, Teresa; Gilbert, Sarah C

    2014-03-01

    Adenoviruses are potent vectors for inducing and boosting cellular immunity to encoded recombinant antigens. However, the widespread seroprevalence of neutralizing antibodies to common human adenovirus serotypes limits their use. Simian adenoviruses do not suffer from the same drawbacks. We have constructed a replication-deficient chimpanzee adenovirus-vectored vaccine expressing the conserved influenza antigens, nucleoprotein (NP), and matrix protein 1 (M1). Here, we report safety and T-cell immunogenicity following vaccination with this novel recombinant simian adenovirus, ChAdOx1 NP+M1, in a first in human dose-escalation study using a 3+3 study design, followed by boosting with modified vaccinia virus Ankara expressing the same antigens in some volunteers. We demonstrate ChAdOx1 NP+M1 to be safe and immunogenic. ChAdOx1 is a promising vaccine vector that could be used to deliver vaccine antigens where strong cellular immune responses are required for protection. PMID:24374965

  3. Human chromosome 16 encodes a factor involved in induction of class II major histocompatibility antigens by interferon gamma.

    PubMed Central

    Bono, M R; Alcaïde-Loridan, C; Couillin, P; Letouzé, B; Grisard, M C; Jouin, H; Fellous, M

    1991-01-01

    Interferon gamma (IFN-gamma) induces expression of class II major histocompatibility complex (MHC)-encoded antigens in immunocompetent cells. To gain further insight into the mechanism of this induction, we prepared somatic cell hybrids between different human cell lines and a murine cell line, RAG, that does not express murine class II MHC antigens before or after treatment with murine IFN-gamma. Some of the resulting cell hybrids express murine class II MHC antigens when treated with murine IFN-gamma. This inducible phenotype is correlated with the presence of human chromosome 16. It has been shown previously that the induction of class I MHC antigens by human IFN-gamma in human-rodent hybrids requires the presence of species-specific factors encoded by chromosome 6, which bears the gene for the human IFN-gamma receptor, and chromosome 21, whose product(s) is necessary for the transduction of human IFN-gamma signals. In this report, we show that the induction of murine class II MHC antigens by human IFN-gamma in the human-RAG cell hybrids requires, likewise, the presence of human chromosomes 6 and 21, in addition to chromosome 16. In some of these hybrids, when all three of these human chromosomes were present, induction of cell-surface HLA-DR antigens was also observed. Our results demonstrate that human chromosome 16 encodes a non-species-specific factor involved in the induction of class II MHC antigens by IFN-gamma. Images PMID:1906174

  4. Recombinant Major Antigenic Protein 2 of Ehrlichia canis: a Potential Diagnostic Tool

    PubMed Central

    Alleman, A. Rick; McSherry, Leo J.; Barbet, Anthony F.; Breitschwerdt, Edward B.; Sorenson, Heather L.; Bowie, Michael V.; Bélanger, Myriam

    2001-01-01

    The major antigenic protein 2 (MAP2) of Ehrlichia canis was cloned and expressed. The recombinant protein was characterized and tested in an enzyme-linked immunosorbent assay (ELISA) format for potential application in the serodiagnosis of canine monocytic ehrlichiosis. The recombinant protein, which contained a C-terminal polyhistidine tag, had a molecular mass of approximately 26 kDa. The antigen was clearly identified by Western immunoblotting using antihistidine antibody and immune serum from an experimentally infected dog. The recombinant MAP2 (rMAP2) was tested in an ELISA format using 141 serum samples from E. canis immunofluorescent antibody (IFA)-positive and IFA-negative dogs. Fifty-five of the serum samples were from dogs experimentally or naturally infected with E. canis and were previously demonstrated to contain antibodies reactive with E. canis by indirect immunofluorescence assays. The remaining 86 samples, 33 of which were from dogs infected with microorganisms other than E. canis, were seronegative. All of the samples from experimentally infected animals and 36 of the 37 samples from naturally infected animals were found to contain antibodies against rMAP2 of E. canis in the ELISA. Only 3 of 53 IFA-negative samples tested positive on the rMAP2 ELISA. There was 100% agreement among IFA-positive samples from experimentally infected animals, 97.3% agreement among IFA-positive samples from naturally infected animals, and 94.3% agreement among IFA-negative samples, resulting in a 97.2% overall agreement between the two assays. These data suggest that rMAP2 of E. canis could be used as a recombinant test antigen for the serodiagnosis of canine monocytic ehrlichiosis. PMID:11427559

  5. Soluble recombinant merozoite surface antigen-142kDa of Plasmodium vivax: An improved diagnostic antigen for vivax malaria.

    PubMed

    Mirahmadi, Hadi; Fallahi, Shirzad; Seyyed Tabaei, Seyyed Javad

    2016-04-01

    Enzyme Linked Immunosorbent Assay (ELISA), as a serological test, can be a beneficial tool for epidemiological studies by screening blood donors and diagnosis of specific antibodies from Plasmodium vivax (P. vivax) infected cases. Since P. vivax cannot easily be acquired in vitro, ELISA assays using total or semi-purified antigens are seldom used. On the basis of this restriction, we examined whether recombinant protein 42 kDa related to C-terminal region of the merozoite surface antigen-1 of P. vivax (MSA-1(42)) could be suitable for serological detection of vivax malaria infection. Purified recombinant protein produced in Escherichia coli (E. coli) (GST-MSA-1(42)) was examined for its ability to bind to IgG antibodies of individuals with patent P. vivax infection. The method was tested with 262 serum samples collected from individuals living in the south and southeastern regions of Iran where malaria is endemic. Samples exposed to Plasmodium falciparum (P. falciparum) infection and patients with other infectious disease (toxoplasmosis, Leishmania infantum infection, echinococcosis and FUO (fever with unknown origin)) except for P. falciparum were residing in non- malaria endemic areas in Iran. Generally, the sensitivity of ELISA evaluated with sera from naturally infected individuals was 86.9%. The specificity value of the ELISA determined with sera from healthy individuals and from individuals with other infectious diseases was 94.05%. The positive predictive value (PPV), negative predictive value (NPV) provided, and the diagnostic efficiency of anti-rPvMSA-1(42) antibody using indirect ELISA were determined 93.58, 87.77 and 91.06% respectively. Our study demonstrated that, because MSA-1(42) kDa contains both the 33 and 19 kDa fragments in its structure, it can serve as the basis for the development of a sensitive serological test which can be used for epidemiological studies, screening blood donors and diagnosis of P. vivax malaria. PMID:26851675

  6. Mycobacterium bovis BCG priming induces a strong potentiation of the antibody response induced by recombinant BCG expressing a foreign antigen.

    PubMed Central

    Gheorghiu, M; Lagranderie, M R; Gicquel, B M; Leclerc, C D

    1994-01-01

    Several recent studies have demonstrated that strong cellular or humoral immune responses can be induced against foreign antigens expressed by recombinant Mycobacterium bovis BCG. It has therefore been suggested that BCG could represent one of the best candidate vectors for live recombinant vaccines. However, a large percentage of the human population has been immunized by BCG, and this priming could modify the immune response to future recombinant BCG vaccines. In the present study, we have therefore compared the immune responses induced in naive and BCG-primed mice by two recombinant BCG vaccines expressing either beta-galactosidase or human immunodeficiency virus type 1 Nef antigens. Our results demonstrated that BCG priming limits the growth of recombinant BCG in mouse spleen or lymph nodes. This reduction in BCG growth was associated with decreased proliferative responses against Nef or beta-galactosidase antigens. This suppression, however, never exceeded 50%. Interestingly, in contrast to these reduced T-cell responses, BCG-primed mice developed high levels of anti-beta-galactosidase antibodies after immunization with recombinant BCG expressing this antigen. This stimulation of antibody responses was not due to polyclonal stimulation or to a nonspecific adjuvant effect of BCG. The isotypic patterns of anti-beta-galactosidase antibody responses induced by the recombinant BCG were similar in naive and BCG-primed mice. These results indicate that priming with BCG will not be a limitation for the use of recombinant BCG vaccines in humans. PMID:7927686

  7. Experimental studies of a vaccine formulation of recombinant human VEGF antigen with aluminum phosphate

    PubMed Central

    Pérez Sánchez, Lincidio; Morera Díaz, Yanelys; Bequet-Romero, Mónica; Ramses Hernández, Gerardo; Rodríguez, Yadira; Castro Velazco, Jorge; Puente Pérez, Pedro; Ayala Avila, Marta; Gavilondo, Jorge V

    2015-01-01

    CIGB-247 is a cancer vaccine that is a formulation of a recombinant protein antigen representative of the human vascular endothelial growth factor (VEGF) with a bacterially-derived adjuvant (VSSP). The vaccine has shown an excellent safety profile in mice, rats, rabbits, not-human primates and in recent clinical trials in cancer patients. Response to the vaccine is characterized by specific antibody titers that neutralize VEGF/VEGFR2 binding and a cytotoxic tumor-specific response. To expand our present anti-VEGF active immunotherapy strategies, we have now studied in mice and non-human primates the effects of vaccination with a formulation of our recombinant VEGF antigen and aluminum phosphate adjuvant (hereafter denominated CIGB-247-A). Administered bi-weekly, CIGB-247-A produces high titers of anti-VEGF IgG blocking antibodies in 2 mice strains. Particularly in BALB/c, the treatment impaired subcutaneous F3II mammary tumor growth and reduced the number of spontaneous lung macro metastases, increasing animals' survival. Spleen cells from specifically immunized mice directly killed F3II tumor cells in vitro. CIGB-247-A also showed to be immunogenic in non-human primates, which developed anti-VEGF blocking antibodies and the ability for specific direct cell cytotoxic responses, all without impairing the healing of deep skin wounds or other side effect. Our results support consideration of aluminum phosphate as a suitable adjuvant for the development of new vaccine formulations using VEGF as antigen. PMID:25891359

  8. Cloning, expression, and antigenic characterization of recombinant protein of Mycoplasma gallisepticum expressed in Escherichia coli.

    PubMed

    Rocha, T S; Tramuta, C; Catania, S; Matucci, A; Giuffrida, M G; Baro, C; Profiti, M; Bertolotti, L; Rosati, S

    2015-04-01

    Mycoplasma gallisepticum (MG) is a member of the most important avian mycoplasmas, causing chronic respiratory disease in chickens and leading to important economic losses in the poultry industry. Recombinant technology represents a strategic approach used to achieve highly reliable and specific diagnostic tests in veterinary diseases control: in particular this aspect is crucial for confirming mycoplasma infection and for maintaining mycoplasma-free breeder flocks. In this study, we identified a component of the pyruvate dehydrogenase dihydrolipoamide acetyltransferase (i.e., E2) protein by 2-dimensional electrophoresis (2-DE), characterized it in immunoblotting assays, and analyzed its recombinant (r-E2) in a rec-ELISA test. For full-length protein expression in Escherichia coli (EC) a point mutation was introduced. A rabbit antiserum produced against r-E2 was tested in a Western Blot using different samples of Mycoplasma species. The results showed the applicability of site-directed mutagenesis, with a good yield of the r-E2 after purification. Also, anti-E2 serum reacted with all the tested MG strains showing no cross reaction with other mycoplasmas. The developed E2 ELISA test was capable of detecting MG antibodies in the sera examined. Those results demonstrate the antigenic stability of the E2 protein which could represent a recombinant antigen with potential diagnostic applications. PMID:25667423

  9. Cryptocaryon irritans recombinant proteins as potential antigens for sero-surveillance of cryptocaryonosis.

    PubMed

    Lokanathan, Y; Mohd-Adnan, A; Kua, B-C; Nathan, S

    2016-09-01

    Cryptocaryonosis is a major problem for mariculture, and the absence of suitable sero-surveillance tools for the detection of cryptocaryonosis makes it difficult to screen Cryptocaryon irritans-infected fish, particularly asymptomatic fish. In this study, we proposed a serum-based assay using selected C. irritans proteins to screen infected and asymptomatic fish. Eight highly expressed genes were chosen from an earlier study on C. irritans expressed sequence tags and ciliate glutamine codons were converted to universal glutamine codons. The chemically synthesized C. irritans genes were then expressed in an Escherichia coli expression host under optimized conditions. Five C. irritans proteins were successfully expressed in E. coli and purified by affinity chromatography. These proteins were used as antigens in an enzyme-linked immunosorbent assay (ELISA) to screen sera from experimentally immunized fish and naturally infected fish. Sera from both categories of fish reacted equally well with the expressed C. irritans recombinant proteins as well as with sonicated theronts. This study demonstrated the utility of producing ciliate recombinant proteins in a heterologous expression host. An ELISA was successfully developed to diagnose infected and asymptomatic fish using the recombinant proteins as antigens. PMID:27086498

  10. Comparison of Z and R3 antigen expression and of genes encoding other antigenic markers in invasive human and bovine Streptococcus agalactiae strains from Norway.

    PubMed

    Maeland, Johan A; Radtke, Andreas

    2013-12-27

    Streptococcus agalactiae (GBS) may cause a variety of infectious diseases in humans caused by human GBS and mastitis in cattle caused by bovine GBS. Over the last few years molecular testing has provided evidence that human and bovine GBS have evolved along diverse phylogenetic lines. In the present study 173 invasive human GBS strains and 52 invasive bovine strains were tested for altogether 18 strain-variable and surface-localized antigenic markers including all 10 capsular polysaccharides (CPS) and proteins including Cβ, the alpha-like proteins, R3 and the recently described Z1 and Z2 antigens. PCR was used to detect encoding genes and antibody-based methods to detect expression of antigens. Thirteen of the 18 markers were detected in isolates of both strain categories. Seven of the ten CPS antigens were detected in both groups with types III and V predominating in the human GBS strains, types IV and V in the bovine isolates. Z1, Z2 and/or R3 expression and the genes encoding Cβ, Cα, Alp1, Alp2/3 or R4 (Rib) were detected in both groups. Protein antigen-CPS associations well known for human strains were essentially the same in the bovine isolates. The results show that in spite of evolution along different lines, human and bovine GBS share a variety of surface-exposed antigenic markers, substantiating close relationship between the two GBS subpopulations. PMID:24120184

  11. The Novelty of Human Cancer/Testis Antigen Encoding Genes in Evolution

    PubMed Central

    Dobrynin, Pavel; Matyunina, Ekaterina; Malov, S. V.; Kozlov, A. P.

    2013-01-01

    In order to be inherited in progeny generations, novel genes should originate in germ cells. Here, we suggest that the testes may play a special “catalyst” role in the birth and evolution of new genes. Cancer/testis antigen encoding genes (CT genes) are predominantly expressed both in testes and in a variety of tumors. By the criteria of evolutionary novelty, the CT genes are, indeed, novel genes. We performed homology searches for sequences similar to human CT in various animals and established that most of the CT genes are either found in humans only or are relatively recent in their origin. A majority of all human CT genes originated during or after the origin of Eutheria. These results suggest relatively recent origin of human CT genes and align with the hypothesis of the special role of the testes in the evolution of the gene families. PMID:23691492

  12. Affinities of recombinant norovirus P dimers for human blood group antigens

    PubMed Central

    Han, Ling; Kitov, Pavel I; Kitova, Elena N; Tan, Ming; Wang, Leyi; Xia, Ming; Jiang, Xi; Klassen, John S

    2013-01-01

    Noroviruses (NoVs), the major cause of viral acute gastroenteritis, recognize histo-blood group antigens (HBGAs) as receptors or attachment factors. To gain a deeper understanding of the interplay between NoVs and their hosts, the affinities of recombinant P dimers (P2's) of a GII.4 NoV (VA387) to a library of 41 soluble analogs of HBGAs were measured using the direct electrospray ionization mass spectrometry assay. The HBGAs contained the A, B, H and Lewis epitopes, with variable sizes (2–6 residues) and different types (1–6). The results reveal that the P2's exhibit a broad specificity for the HBGAs and bind to all of the oligosaccharides tested. Overall, the affinities are relatively low, ranging from 400 to 3000 M−1 and are influenced by the chain type: 3 > 1 ≈ 2 ≈ 4 ≈ 5 ≈ 6 for H antigens; 6 > 1 ≈ 3 ≈ 4 ≈ 5 > 2 for A antigens; 3 > 1 ≈ 4 ≈ 5 ≈ 6 > 2 for B antigens, but not by chain length. The highest-affinity ligands are B type 3 (3000 ± 300 M−1) and A type 6 (2350 ± 60 M−1). While the higher affinity to the type 3 H antigen was previously observed, preferential binding to the types 6 and 3 antigens with A and B epitopes, respectively, has not been previously reported. A truncated P domain dimer (lacking the C-terminal arginine cluster) exhibits similar binding. The central-binding motifs in the HBGAs were identified by molecular-docking simulations. PMID:23118206

  13. Silencing of T lymphocytes by antigen-driven programmed death in recombinant adeno-associated virus vector–mediated gene therapy

    PubMed Central

    Velazquez, Victoria M.; Bowen, David G.

    2009-01-01

    Recombinant adeno-associated virus (rAAV) vectors are considered promising for human gene replacement because they facilitate stable expression of therapeutic proteins in transduced tissues. Whether the success of gene therapy will be influenced by cellular immune responses targeting transgene-encoded proteins that are potentially immunogenic is unknown. Here we characterized CD8+ T-cell activity against β-galactosidase and enhanced green fluorescent protein, model antigens containing major histocompatibility complex (MHC) class I epitopes that are constitutively produced in murine skeletal muscle after rAAV vector transduction. Antigen-specific CD8+ T cells were detected in the spleen and liver of mice within 7 days of muscle transduction. CD8+ T-cell frequencies in these organs were stable, and effector functions were intact for months despite ongoing antigen production in muscle. CD8+ T cells also infiltrated transduced muscle, where frequencies were at least 5-fold higher than in untransduced spleen and liver. Significantly, the majority of antigen-specific CD8+ T cells in vector-transduced muscle were not functional. Loss of function in the muscle was associated with programmed death of the effector cells. Stable gene expression therefore depended on selective death of CD8+ T cells at the site of antigen production, an effective mechanism for subverting immunity that is also potentially reversible. PMID:18566327

  14. Characterisation of recombinant immunoreactive antigens of the scab mite Sarcoptes scabiei.

    PubMed

    Kuhn, C; Lucius, R; Matthes, H F; Meusel, G; Reich, B; Kalinna, B H

    2008-05-31

    Sarcoptic mange (or scabies) is an important skin disease which can affect a variety of species including humans, cattle, goats, sheep, horses, pigs, rabbits, and dogs. Approximately 300 million people are affected worldwide and in lifestock animals the infestation may lead to substantial economic losses caused by depression in growth and feed conversion rates. Diagnosis of Sarcoptes infestation is difficult and only a few serological tests have been developed using whole mite antigen for diagnosis of mange in animals. Here we describe the isolation and characterisation of cDNAs of several immunoreactive clones and their recombinant expression in Escherichia coli. Three of the proteins contain repetitive sequences which suggests that they might be involved in immune evasion. The application of these antigens in serodiagnosis and the suitability for diagnosis is discussed. PMID:18359167

  15. mTOR inhibition improves antitumor effects of vaccination with antigen-encoding RNA.

    PubMed

    Diken, Mustafa; Kreiter, Sebastian; Vascotto, Fulvia; Selmi, Abderraouf; Attig, Sebastian; Diekmann, Jan; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

    2013-12-01

    Vaccination with in vitro transcribed RNA encoding tumor antigens is an emerging approach in cancer immunotherapy. Attempting to further improve RNA vaccine efficacy, we have explored combining RNA with immunomodulators such as rapamycin. Rapamycin, the inhibitor of mTOR, was used originally for immunosuppression. Recent reports in mouse systems, however, suggest that mTOR inhibition may enhance the formation and differentiation of the memory CD8(+) T-cell pool. Because memory T-cell formation is critical to the outcome of vaccination approaches, we studied the impact of rapamycin on the in vivo primed RNA vaccine-induced immune response using the chicken ovalbumin-expressing B16 melanoma model in C57BL/6 mice. Our data show that treatment with rapamycin at the effector-to-memory transition phase skews the vaccine-induced immune response toward the formation of a quantitatively and qualitatively superior memory pool and results in a better recall response. Tumor-infiltrating immune cells from these mice display a favorable ratio of effector versus suppressor cell populations. Survival of mice treated with the combined regimen of RNA vaccination with rapamycin is significantly longer (91.5 days) than that in the control groups receiving only one of these compounds (32 and 46 days, respectively). Our findings indicate that rapamycin enhances therapeutic efficacy of antigen-specific CD8(+) T cells induced by RNA vaccination, and we propose further clinical exploration of rapamycin as a component of immunotherapeutic regimens. PMID:24778131

  16. Superior efficacy of secreted over somatic antigen display in recombinant Salmonella vaccine induced protection against listeriosis.

    PubMed Central

    Hess, J; Gentschev, I; Miko, D; Welzel, M; Ladel, C; Goebel, W; Kaufmann, S H

    1996-01-01

    Vaccination provides the most potent measure against infectious disease, and recombinant (r) viable vaccines expressing defined pathogen-derived antigens represent powerful candidates for future vaccination strategies. In a new approach we constructed r-aroA- Salmonella typhimurium displaying p60 or listeriolysin (Hly) antigen of Listeria monocytogenes in secreted or somatic form in the host cell. Vaccination of mice with r-aroA- S. typhimurium induced protection against the intracellular pathogen L. monocytogenes only with secreted and not with somatic antigen. Secreted Hly was slightly more potent in inducing protective immunity than secreted p60. Both r-aroA- S. typhimurium secreting p60 in the endosome and r-aroA- S. typhimurium secreting Hly in the cytosol induced protective CD4+ and CD8+ T-cells suggesting CD8+ T-cell stimulation independent from intracellular residence of r-aroA- S. typhimurium carriers. Hence, not only the type of antigen but also its display by the r-carrier within the host cell critically influences vaccine efficacy. Images Fig. 1 PMID:8643654

  17. Recombinant antigen-based enzyme-linked immunosorbent assay for diagnosis of Baylisascaris procyonis larva migrans.

    PubMed

    Dangoudoubiyam, Sriveny; Vemulapalli, Ramesh; Ndao, Momar; Kazacos, Kevin R

    2011-10-01

    Baylisascaris larva migrans is an important zoonotic disease caused by Baylisascaris procyonis, the raccoon roundworm, and is being increasingly considered in the differential diagnosis of eosinophilic meningoencephalitis in children and young adults. Although a B. procyonis excretory-secretory (BPES) antigen-based enzyme-linked immunosorbent assay (ELISA) and a Western blot assay are useful in the immunodiagnosis of this infection, cross-reactivity remains a major problem. Recently, a recombinant B. procyonis antigen, BpRAG1, was reported for use in the development of improved serological assays for the diagnosis of Baylisascaris larva migrans. In this study, we tested a total of 384 human patient serum samples in a BpRAG1 ELISA, including samples from 20 patients with clinical Baylisascaris larva migrans, 137 patients with other parasitic infections (8 helminth and 4 protozoan), and 227 individuals with unknown/suspected parasitic infections. A sensitivity of 85% and a specificity of 86.9% were observed with the BpRAG1 ELISA, compared to only 39.4% specificity with the BPES ELISA. In addition, the BpRAG1 ELISA had a low degree of cross-reactivity with antibodies to Toxocara infection (25%), while the BPES antigen showed 90.6% cross-reactivity. Based on these results, the BpRAG1 antigen has a high degree of sensitivity and specificity and should be very useful and reliable in the diagnosis and seroepidemiology of Baylisascaris larva migrans by ELISA. PMID:21832102

  18. Bovine immunoprotection against Rhipicephalus (Boophilus) microplus with recombinant Bm86-Campo Grande antigen.

    PubMed

    Cunha, Rodrigo Casquero; Pérez de León, Adalberto Angel; Leite, Fábio Pereira Leivas; Pinto, Luciano da Silva; Dos Santos Júnior, Alceu Gonçalves; Andreotti, Renato

    2012-01-01

    The southern cattle fever tick, Rhipicephalus (Boophilus) microplus, is no doubt the most economically important ectoparasite of cattle globally. The inappropriate use of chemical acaricides has driven the evolution of resistance in populations of R. (B.) microplus. Anti-tick vaccines represent a technology that can be combined with acaricides in integrated control programs to mitigate the impact of R. (B.) microplus. The recombinant form of Bm86 antigen from the Campo Grande (rBm86-CG) strain of R. (B.) microplus was produced using the Pichiapastoris expression system to test its ability to immunoprotect cattle against tick infestation. Secretion of rBm86-CG by P. pastoris through the bioprocess reported here simplified purification of the antigen. A specific humoral immune response was detected by ELISA in vaccinated cattle. Immunoblot results revealed that polyclonal antibodies from vaccinated cattle recognized a protein in larval extracts with a molecular weight corresponding to Bm86. The rBm86-CG antigen showed 31% efficacy against the Campo Grande strain of R. (B.) microplus infesting vaccinated cattle. The rBm86-CG is an antigen that could be used in a polyvalent vaccine as part of an integrated program for the control of R. (B.) microplus in the region that includes Mato Grosso do Sul. PMID:23070436

  19. Antigenic composition and immunoreactivity differences between HEV recombinant capsid proteins generated from different genotypes.

    PubMed

    Behloul, Nouredine; Wen, Jiyue; Dai, Xing; Dong, Chen; Meng, Jihong

    2015-08-01

    Appreciable variability has been observed in hepatitis E virus (HEV) serological diagnostics. Four recombinant proteins (p166s) were generated from position 452 to 617 aa of ORF2 of different HEV genotypes and used in an indirect ELISA to detect anti-HEV IgMs and IgGs in serially diluted sera of patients infected with different HEV genotypes (genotype 1, n=15; genotype 3, n=12; genotype 4, n=17). To evaluate the differences at a conformational level, 3D-structure models of p166s were predicted, and different bioinformatics tools were used to analyze the antigenic composition. With both anti-HEV IgMs and IgGs antibodies, there was a considerable variability between the four antigens immunoreactivities. In silico results revealed the region 483-533 aa with the highest antigenic potential and contains six key aa at positions 488, 489, 512, 533, 483 and 530. This immunoreactivity variation could affect diagnosis results and seroprevalence estimations and the identification in silico of a region highly antigenic would guide the development of efficient serological assays and epitope-based vaccines. PMID:26122075

  20. Biochemical characterization of the recombinant Boophilus microplus Bm86 antigen expressed by transformed Pichia pastoris cells.

    PubMed

    Montesino, R; Cremata, J; Rodríguez, M; Besada, V; Falcón, V; de la Fuente, J

    1996-02-01

    In the present paper we report the biochemical characteristics of the recombinant tick (Boophilus microplus) gut antigen Bm86 that previously has been cloned, expressed and recovered at high levels in the methylotrophic yeast Pichia pastoris. The results demonstrate that rBm86 had a modification at position 92 (Thr replaced by Ile) and aggregated, forming particles ranging between 17 and 40 nm. The rBm86 was N-glycosylated, having at least two non-glycosylated sequons (Asn-329 and Asn-363) and a ratio of only 0.4/65 (free Cys/total Cys)/mol of protein. PMID:8867893

  1. Evaluation of liver fluke recombinant cathepsin B-1 protease as a serodiagnostic antigen for human opisthorchiasis.

    PubMed

    Sripa, Jittiyawadee; Brindley, Paul J; Sripa, Banchob; Loukas, Alex; Kaewkes, Sasithorn; Laha, Thewarach

    2012-03-01

    A cathepsin B-like cysteine protease belonging to family C1 is abundantly expressed in the transcriptome and proteome of the carcinogenic liver fluke of humans, Opisthorchis viverrini. This enzyme is present in excretory/secretory (ES) products released by parasites cultured in vitro. This study evaluated the performance of recombinant O. viverrini cathepsin B1 (rOv-CB-1) as an antigen for immunodiagnosis of opisthorchiasis. The full length Ov-CB-1 cDNA was cloned and recombinant protein was produced in catalytically active form in Pichia pastoris. The recombinant Ov-CB-1 (rOv-CB-1) was affinity purified via nickel-NTA chromatography and tested in enzyme-linked immunosorbent assays (ELISA) with human sera from an opisthorchiasis endemic area. Sera from egg-positive O. viverrini infections produced a strong IgG antibody response to rOv-CB-1 both in ELISA and immunoblot analysis. The sensitivity and specificity of the ELISA test was 67% and 81%, respectively. These findings support the feasibility of using recombinant Ov-CB-1 in ELISA for the serodiagnosis of human opisthorchiasis. PMID:21704728

  2. Replication of simian virus 40 origin-containing DNA during infection with a recombinant Autographa californica multiple nuclear polyhedrosis virus expressing large T antigen.

    PubMed Central

    Martin, D W; Weber, P C

    1997-01-01

    Autographica californica multiple nuclear polyhedrosis virus (AcMNPV) has been shown to encode many of the enzymes involved in the replication of its own DNA. Although the AcMNPV genome contains multiple sets of reiterated sequences that are thought to function as origins of DNA replication, no initiator protein has yet been identified in the set of viral replication enzymes. In this study, the ability of a heterologous origin initiator system to promote DNA replication in AcMNPV-infected cells was examined. A recombinant AcMNPV that expressed the simian virus 40 (SV40) large T antigen was surprisingly found to induce the efficient replication of a transfected plasmid containing an SV40 origin. This replication was subsequently found to involve three essential components: (i) T antigen, since replication of SV40 origin-containing plasmids was not induced by wild-type AcMNPV which did not express this protein; (ii) an intact SV40 core origin, since deletion of specific functional motifs within the origin resulted in a loss of replicative abilities; and (iii) one or more AcMNPV-encoded proteins, since viral superinfection was required for plasmid amplification. Characterization of the replicated DNA revealed that it existed as a high-molecular-weight concatemer and underwent significant levels of homologous recombination between inverted repeat sequences. These properties were consistent with an AcMNPV-directed mode of DNA synthesis rather than that of SV40 and suggested that T antigen-SV40 origin complexes may be capable of initiating DNA replication reactions that can be completed by AcMNPV-encoded enzymes. PMID:8985377

  3. Expression, purification, immunogenicity, and protective efficacy of a recombinant Tc24 antigen as a vaccine against Trypanosoma cruzi infection in mice.

    PubMed

    Martinez-Campos, Viridiana; Martinez-Vega, Pedro; Ramirez-Sierra, Maria Jesus; Rosado-Vallado, Miguel; Seid, Christopher A; Hudspeth, Elissa M; Wei, Junfei; Liu, Zhuyun; Kwityn, Cliff; Hammond, Molly; Ortega-López, Jaime; Zhan, Bin; Hotez, Peter J; Bottazzi, Maria Elena; Dumonteil, Eric

    2015-08-26

    The Tc24 calcium binding protein from the flagellar pocket of Trypanosoma cruzi is under evaluation as a candidate vaccine antigen against Chagas disease. Previously, a DNA vaccine encoding Tc24 was shown to be an effective vaccine (both as a preventive and therapeutic intervention) in mice and dogs, as evidenced by reductions in T. cruzi parasitemia and cardiac amastigotes, as well as reduced cardiac inflammation and increased host survival. Here we developed a suitable platform for the large scale production of recombinant Tc24 (rTc24) and show that when rTc24 is combined with a monophosphoryl-lipid A (MPLA) adjuvant, the formulated vaccine induces a Th1-biased immune response in mice, comprised of elevated IgG2a antibody levels and interferon-gamma levels from splenocytes, compared to controls. These immune responses also resulted in statistically significant decreased T. cruzi parasitemia and cardiac amastigotes, as well as increased survival following T. cruzi challenge infections, compared to controls. Partial protective efficacy was shown regardless of whether the antigen was expressed in Escherichia coli or in yeast (Pichia pastoris). While mouse vaccinations will require further modifications in order to optimize protective efficacy, such studies provide a basis for further evaluations of vaccines comprised of rTc24, together with alternative adjuvants and additional recombinant antigens. PMID:26192358

  4. Detection of Q Fever Specific Antibodies Using Recombinant Antigen in ELISA with Peroxidase Based Signal Amplification

    PubMed Central

    Chen, Hua-Wei; Zhang, Zhiwen; Glennon, Erin; Ching, Wei-Mei

    2014-01-01

    Currently, the accepted method for Q fever serodiagnosis is indirect immunofluorescent antibody assay (IFA) using the whole cell antigen. In this study, we prepared the recombinant antigen of the 27-kDa outer membrane protein (Com1) which has been shown to be recognized by Q fever patient sera. The performance of recombinant Com1 was evaluated in ELISA by IFA confirmed serum samples. Due to the low titers of IgG and IgM in Q fever patients, the standard ELISA signals were further amplified by using biotinylated anti-human IgG or IgM plus streptavidin-HRP polymer. The modified ELISA can detect 88% (29 out of 33) of Q fever patient sera collected from Marines deployed to Iraq. Less than 5% (5 out of 156) of the sera from patients with other febrile diseases reacted with the Com1. These results suggest that the modified ELISA using Com1 may have the potential to improve the detection of Q fever specific antibodies. PMID:26904739

  5. Cloning and characterization of a potentially protective chitinase-like recombinant antigen from Wuchereria bancrofti.

    PubMed Central

    Raghavan, N; Freedman, D O; Fitzgerald, P C; Unnasch, T R; Ottesen, E A; Nutman, T B

    1994-01-01

    While there is no direct evidence demonstrating the existence of protective immunity to Wuchereria bancrofti infection in humans, the presence of individuals, in populations in areas where infection is endemic, with no clinical evidence of past or current infection despite appreciable exposure to the infective larvae, suggests that protective immunity to filarial parasites may occur naturally. Earlier work indicated that such putatively immune individuals generated antibodies to a 43-kDa antigen from larval extracts of the related filarial parasite Brugia malayi that was recognized by only 8% of the infected population. With rabbit antiserum raised against this 43-kDa antigen, this current study identified a recombinant clone, WbN43, with an insert size of 2.3 kb, from a W. bancrofti genomic expression library. The recombinant fusion protein was differentially recognized by the putatively immune individuals but not by the infected patients. The coding sequence (684 bp) from the 5' end had significant sequence similarity to chitinases from Serratia marcescens, Bacillus circulans, Streptomyces plicatus, and B. malayi. Peptide sequencing of the expressed product also defined a chitinase-like sequence. Molecular characterization indicated WbN43 to be a low-copy-number gene, with expression predominantly in infective larvae and microfilariae but not in adult parasites. Images PMID:8168956

  6. Novel Recombinant Hepatitis B Virus Vectors Efficiently Deliver Protein and RNA Encoding Genes into Primary Hepatocytes

    PubMed Central

    Hong, Ran; Bai, Weiya; Zhai, Jianwei; Liu, Wei; Li, Xinyan; Zhang, Jiming; Cui, Xiaoxian; Zhao, Xue; Ye, Xiaoli; Deng, Qiang; Tiollais, Pierre; Wen, Yumei

    2013-01-01

    Hepatitis B virus (HBV) has extremely restricted host and hepatocyte tropism. HBV-based vectors could form the basis of novel therapies for chronic hepatitis B and other liver diseases and would also be invaluable for the study of HBV infection. Previous attempts at developing HBV-based vectors encountered low yields of recombinant viruses and/or lack of sufficient infectivity/cargo gene expression in primary hepatocytes, which hampered follow-up applications. In this work, we constructed a novel vector based on a naturally occurring, highly replicative HBV mutant with a 207-bp deletion in the preS1/polymerase spacer region. By applying a novel insertion strategy that preserves the continuity of the polymerase open reading frame (ORF), recombinant HBV (rHBV) carrying protein or small interfering RNA (siRNA) genes were obtained that replicated and were packaged efficiently in cultured hepatocytes. We demonstrated that rHBV expressing a fluorescent reporter (DsRed) is highly infective in primary tree shrew hepatocytes, and rHBV expressing HBV-targeting siRNA successfully inhibited antigen expression from coinfected wild-type HBV. This novel HBV vector will be a powerful tool for hepatocyte-targeting gene delivery, as well as the study of HBV infection. PMID:23552416

  7. Western Immunoblotting with Five Treponema pallidum Recombinant Antigens for Serologic Diagnosis of Syphilis

    PubMed Central

    Sambri, Vittorio; Marangoni, Antonella; Eyer, Christina; Reichhuber, Christine; Soutschek, Erwin; Negosanti, Massimo; D'Antuono, Antonietta; Cevenini, Roberto

    2001-01-01

    Five immunodominant Treponema pallidum recombinant polypeptides (rTpN47, rTmpA, rTpN37, rTpN17, and rTpN15) were blotted onto strips, and 450 sera (200 from blood donors, 200 from syphilis patients, and 50 potentially cross-reactive) were tested to evaluate the diagnostic performance of recombinant Western blotting (recWB) in comparison with in-house whole-cell lysate antigen-based immunoblotting (wclWB) and T. pallidum hemagglutination (MHA-TP) for the laboratory diagnosis of syphilis. None of the serum specimens from blood donors or from potential cross-reactors gave a positive result when evaluated by recWB, wclWB, or MHA-TP. The evaluation of the immunoglobulin G immune response by recWB in sera from patients with different stages of syphilis showed that rTmpA was the most frequently identified antigen (95%), whereas only 41% of the specimens were reactive to rTpN37. The remaining recombinant polypeptides were recognized as follows: rTpN47, 92.5%; rTpN17, 89.5%; and rTpN15, 67.5%. The agreement between recWB and MHA-TP was 95.0% (100% with sera from patients with latent and late disease), and the concordance between wclWB and MHA-TP was 92.0%. The overall concordance between recWB and wclWB was 97.5% (100% with sera from patients with secondary and late syphilis and 94.6 and 98.6% with sera from patients with primary and latent syphilis, respectively). The overall sensitivity of recWB was 98.8% and the specificity was 97.1% with MHA-TP as the reference method. These values for sensitivity and specificity were slightly superior to those calculated for wclWB (sensitivity, 97.1%, and specificity, 96.1%). With wclWB as the standard test, the sensitivity and specificity of recWB were 98.9 and 99.3%, respectively. These findings suggest that the five recombinant polypeptides used in this study could be used as substitutes for the whole-cell lysate T. pallidum antigens and that this newly developed recWB test is a good, easy-to-use confirmatory method for the

  8. Recombinant antibodies encoded by IGHV1-69 react with pUL32, a phosphoprotein of cytomegalovirus and B-cell superantigen

    PubMed Central

    Steininger, Christoph; Widhopf, George F.; Ghia, Emanuela M.; Morello, Christopher S.; Vanura, Katrina; Sanders, Rebecca; Spector, Deborah; Guiney, Don; Jäger, Ulrich

    2012-01-01

    Leukemia cells from patients with chronic lymphocytic leukemia (CLL) express a highly restricted immunoglobulin heavy variable chain (IGHV) repertoire, suggesting that a limited set of antigens reacts with leukemic cells. Here, we evaluated the reactivity of a panel of different CLL recombinant antibodies (rAbs) encoded by the most commonly expressed IGHV genes with a panel of selected viral and bacterial pathogens. Six different CLL rAbs encoded by IGHV1-69 or IGHV3-21, but not a CLL rAb encoded by IGHV4-39 genes, reacted with a single protein of human cytomegalovirus (CMV). The CMV protein was identified as the large structural phosphoprotein pUL32. In contrast, none of the CLL rAbs bound to any other structure of CMV, adenovirus serotype 2, Salmonella enterica serovar Typhimurium, or of cells used for propagation of these microorganisms. Monoclonal antibodies or humanized rAbs of irrelevant specificity to pUL32 did not react with any of the proteins present in the different lysates. Still, rAbs encoded by a germ line IGHV1-69 51p1 allele from CMV-seropositive and -negative adults also reacted with pUL32. The observed reactivity of multiple different CLL rAbs and natural antibodies from CMV-seronegative adults with pUL32 is consistent with the properties of a superantigen. PMID:22234695

  9. Sero-diagnosis of surra exploiting recombinant VSG antigen based ELISA for surveillance.

    PubMed

    Sengupta, P P; Rudramurthy, G R; Ligi, M; Roy, M; Balamurugan, V; Krishnamoorthy, P; Nagalingam, M; Singh, L; Rahman, H

    2014-10-15

    Trypanosoma evansi, a haemoflagellate, causes "surra" an important chronic wasting disease of a wide range of wild and domestic herbivorous and carnivorous animals including cattle, buffaloes, camels, horses, etc. The untreated recovered animal can act as a carrier without exhibiting the disease symptoms and can be a source of infection to healthy animals. The diagnosis and subsequent treatment of the carrier animals is helpful to curb the disease. As the parasitaemia in carrier animals is very scanty, the conventional blood smear examination, which is widely practiced in the field, cannot detect such condition. For this purpose improved diagnostics are very much useful for mass sero-screening test such as ELISA. In the present study, the VSG of T. evansi was expressed in prokaryotic system (E. coli) and thereafter its immunoreactivity has been evaluated in immuno blot and enzyme immuno assay. The expressed protein showed 95.6% sensitivity, 98.0% specificity and 0.93 Cohen's kappa value, when compared with standard antigens. The developed antigen has also been validated with field serum samples from bovine, camel and horse collected from different states of India. The data showed that the developed recombinant antigen can be a diagnostic tool to detect carrier animals as well as control of the disease. PMID:25269987

  10. Effect of particulation on the immunogenic and protective properties of the recombinant Bm86 antigen expressed in Pichia pastoris.

    PubMed

    García-García, J C; Montero, C; Rodríguez, M; Soto, A; Redondo, M; Valdés, M; Méndez, L; de la Fuente, J

    1998-02-01

    The recombinant Bm86 tick antigen expressed in Pichia pastoris is obtained in a highly particulated form, as a distinguish feature of this expression system. This particulated protein, the active principle of the recombinant vaccine Gavac against the cattle tick, have shown high immunogenic and protective properties, probably associated with its own characteristics. To evaluate the effects of particulation on the properties of Bm86, three groups of calves were immunized with particulated or non-particulated recombinant Bm86 and the anti-Bm86 antibody response determined. Animals were challenged with a controlled tick infestation and the protective capacities of both proteins assessed. Humoral immune response and protection in cattle vaccinated with the particulated antigen were higher. These experiments suggested that particulation of the Bm86 expressed in P. pastoris is an important feature for the protective properties of the antigen in vaccine preparations. PMID:9607058

  11. Immunogenicity of recombinant BCGs expressing predicted antigenic epitopes of bovine viral diarrhea virus E2 gene.

    PubMed

    Liu, Dongxu; Lu, Huijun; Shi, Kun; Su, Fengyan; Li, Jianming; Du, Rui

    2014-10-01

    To develop a vaccine to prevent diseases caused by Mycobacterium tuberculosis and bovine viral diarrhea virus (BVDV) simultaneously, recombinant Bacillus Calmette-Guerin (rBCG) vaccines expressing different regions of the BVDV E2 gene were constructed. Using DNASTAR 6.0 software, potential antigenic epitopes were predicted, and six regions were chosen to generate recombinant plasmids with the pMV361 vector (pMV361-E2-1, pMV361-E2-2, pMV361-E2-3, pMV361-E2-4, pMV361-E2-5 and pMV361-E2-6, respectively). The recombinant plasmids were transformed into BCG, and protein expression was thermally induced at 45 °C. Mice were immunized with 5 × 10(6) CFU/200 µL of each rBCG strain. Compared with other groups, BVDV E2 specific antibody titers were higher in mice immunized with rBCG-E2-6. Ratios and numbers of CD4+, CD8+ and IL-12 expressing spleen lymphocytes of the rBCG-E2-6 group also were higher than those of other groups. Thus, the rBCG-E2-6 vaccine showed the highest immunogenicity of all groups based on the humoral and cellular responses to vaccination. PMID:25135492

  12. Antigenic validation of recombinant hemagglutinin-neuraminidase protein of Newcastle disease virus expressed in Saccharomyces cerevisiae.

    PubMed

    Khulape, S A; Maity, H K; Pathak, D C; Mohan, C Madhan; Dey, S

    2015-09-01

    The outer membrane glycoprotein, hemagglutinin-neuraminidase (HN) of Newcastle disease virus (NDV) is important for virus infection and subsequent immune response by host, and offers target for development of recombinant antigen-based immunoassays and subunit vaccines. In this study, the expression of HN protein of NDV is attempted in yeast expression system. Yeast offers eukaryotic environment for protein processing and posttranslational modifications like glycosylation, in addition to higher growth rate and easy genetic manipulation. Saccharomyces cerevisiae was found to be better expression system for HN protein than Pichia pastoris as determined by codon usage analysis. The complete coding  sequence of HN gene was amplified with the histidine tag, cloned in pESC-URA under GAL10 promotor and transformed in Saccharomyces cerevisiae. The recombinant HN (rHN) protein was characterized by western blot, showing glycosylation heterogeneity as observed with other eukaryotic expression systems. The recombinant protein was purified by affinity column purification. The protein could be further used as subunit vaccine. PMID:26435147

  13. Mucosal vaccination with recombinant adenovirus encoding nucleoprotein provides potent protection against influenza virus infection.

    PubMed

    Kim, So-Hee; Kim, Joo Young; Choi, Youngjoo; Nguyen, Huan H; Song, Man Ki; Chang, Jun

    2013-01-01

    Influenza vaccines that target the highly variable surface glycoproteins hemagglutinin and neuraminidase cause inconvenience of having vaccination every year. For this reason, development of universal vaccines targeting conserved viral components is needed. In this study, we generated recombinant adenovirus (rAd) vaccine encoding nucleoprotein (NP) of A/PR/8/34 influenza virus, designated rAd/NP. BALB/c mice were immunized intranasally or sublingually with rAd/NP vaccine and subsequently challenged with lethal doses of heterologous as well as homologous influenza viruses. We found that intranasal immunization of rAd/NP elicited strong mucosal IgA responses as well as stronger CD8 T-cell responses toward immunodominant K(d)-restricted NP147-155 epitope than sublingual immunization. Importantly, only single intranasal but not sublingual immunization of rAd/NP provides potent protection against both homologous and heterologous influenza virus challenges. These results suggest that recombinant rAd/NP could be a universal vaccine candidate for mucosal administration against influenza virus. PMID:24086536

  14. Protection of Mice from Fatal Measles Encephalitis by Vaccination with Vaccinia Virus Recombinants Encoding Either the Hemagglutinin or the Fusion Protein

    NASA Astrophysics Data System (ADS)

    Drillien, Robert; Spehner, Daniele; Kirn, Andre; Giraudon, Pascale; Buckland, Robin; Wild, Fabian; Lecocq, Jean-Pierre

    1988-02-01

    Vaccinia virus recombinants encoding the hemagglutinin or fusion protein of measles virus have been constructed. Infection of cell cultures with the recombinants led to the synthesis of authentic measles proteins as judged by their electrophoretic mobility, recognition by antibodies, glycosylation, proteolytic cleavage, and presentation on the cell surface. Mice vaccinated with a single dose of the recombinant encoding the hemagglutinin protein developed antibodies capable of both inhibiting hemagglutination activity and neutralizing measles virus, whereas animals vaccinated with the recombinant encoding the fusion protein developed measles neutralizing antibodies. Mice vaccinated with either of the recombinants resisted a normally lethal intracerebral inoculation of a cell-associated measles virus subacute sclerosing panencephalitis strain.

  15. Coevolution between Nuclear-Encoded DNA Replication, Recombination, and Repair Genes and Plastid Genome Complexity

    PubMed Central

    Zhang, Jin; Ruhlman, Tracey A.; Sabir, Jamal S. M.; Blazier, John Chris; Weng, Mao-Lun; Park, Seongjun; Jansen, Robert K.

    2016-01-01

    Disruption of DNA replication, recombination, and repair (DNA-RRR) systems has been hypothesized to cause highly elevated nucleotide substitution rates and genome rearrangements in the plastids of angiosperms, but this theory remains untested. To investigate nuclear–plastid genome (plastome) coevolution in Geraniaceae, four different measures of plastome complexity (rearrangements, repeats, nucleotide insertions/deletions, and substitution rates) were evaluated along with substitution rates of 12 nuclear-encoded, plastid-targeted DNA-RRR genes from 27 Geraniales species. Significant correlations were detected for nonsynonymous (dN) but not synonymous (dS) substitution rates for three DNA-RRR genes (uvrB/C, why1, and gyrA) supporting a role for these genes in accelerated plastid genome evolution in Geraniaceae. Furthermore, correlation between dN of uvrB/C and plastome complexity suggests the presence of nucleotide excision repair system in plastids. Significant correlations were also detected between plastome complexity and 13 of the 90 nuclear-encoded organelle-targeted genes investigated. Comparisons revealed significant acceleration of dN in plastid-targeted genes of Geraniales relative to Brassicales suggesting this correlation may be an artifact of elevated rates in this gene set in Geraniaceae. Correlation between dN of plastid-targeted DNA-RRR genes and plastome complexity supports the hypothesis that the aberrant patterns in angiosperm plastome evolution could be caused by dysfunction in DNA-RRR systems. PMID:26893456

  16. Coevolution between Nuclear-Encoded DNA Replication, Recombination, and Repair Genes and Plastid Genome Complexity.

    PubMed

    Zhang, Jin; Ruhlman, Tracey A; Sabir, Jamal S M; Blazier, John Chris; Weng, Mao-Lun; Park, Seongjun; Jansen, Robert K

    2016-01-01

    Disruption of DNA replication, recombination, and repair (DNA-RRR) systems has been hypothesized to cause highly elevated nucleotide substitution rates and genome rearrangements in the plastids of angiosperms, but this theory remains untested. To investigate nuclear-plastid genome (plastome) coevolution in Geraniaceae, four different measures of plastome complexity (rearrangements, repeats, nucleotide insertions/deletions, and substitution rates) were evaluated along with substitution rates of 12 nuclear-encoded, plastid-targeted DNA-RRR genes from 27 Geraniales species. Significant correlations were detected for nonsynonymous (dN) but not synonymous (dS) substitution rates for three DNA-RRR genes (uvrB/C, why1, and gyrA) supporting a role for these genes in accelerated plastid genome evolution in Geraniaceae. Furthermore, correlation between dN of uvrB/C and plastome complexity suggests the presence of nucleotide excision repair system in plastids. Significant correlations were also detected between plastome complexity and 13 of the 90 nuclear-encoded organelle-targeted genes investigated. Comparisons revealed significant acceleration of dN in plastid-targeted genes of Geraniales relative to Brassicales suggesting this correlation may be an artifact of elevated rates in this gene set in Geraniaceae. Correlation between dN of plastid-targeted DNA-RRR genes and plastome complexity supports the hypothesis that the aberrant patterns in angiosperm plastome evolution could be caused by dysfunction in DNA-RRR systems. PMID:26893456

  17. Generation of recombinant rabies viruses encoding NanoLuc luciferase for antiviral activity assays.

    PubMed

    Anindita, Paulina Duhita; Sasaki, Michihito; Nobori, Haruaki; Sato, Akihiko; Carr, Michael; Ito, Naoto; Sugiyama, Makoto; Orba, Yasuko; Sawa, Hirofumi

    2016-04-01

    Rabies is an invariably fatal disease caused by Rabies virus (RABV), a member of the family Rhabdoviridae, genus Lyssavirus. Once central nervous infection occurs and symptoms develop, the case fatality rate approaches 100% despite availability of post-exposure prophylaxis. Therefore, new antiviral therapies for rabies are urgently required. Antivirals which can inhibit virus replication can be identified through screening of small compounds, however, as RABV infection does not generate easily discernible cytopathic effects in vitro, cell viability assays may not be feasible to observe antiviral activity of small compounds against RABV. In this study, recombinant RABVs (rRABVs) encoding NanoLuc luciferase (NanoLuc) were generated to facilitate the screening of small compound libraries. NanoLuc expression was confirmed in single-step growth cures of virus infection and showed that the rRABVs were capable of viral replication without decrease of luciferase activity through ten serial passages. Furthermore, the rRABVs were able to quantify the antiviral activity of the nucleoside analogue ribavirin against RABV in vitro. These findings confirm the potential of the rRABV encoding NanoLuc system to facilitate screening of small compounds to inhibit RABV infection. PMID:26869397

  18. Characterization of the gene encoding the polymorphic immunodominant molecule, a neutralizing antigen of Theileria parva

    SciTech Connect

    Toye, P.G.; Metzelaar, M.J.; Wijngaard, P.L.J.

    1995-08-01

    Theileria parva, a tick-transmitted protozoan parasite related to Plasmodium spp., causes the disease East Coast fever, an acute and usually fatal lymphoproliferative disorder of cattle in Africa. Previous studies using sera from cattle that have survived infection identified a polymorphic immunodominant molecule (PIM) that is expressed by both the infective sporozoite stage of the parasite and the intracellular schizont. Here we show that mAb specific for the PIM Ag can inhibit sporozoite invasion of lymphocytes in vitro. A cDNA clone encoding the PIM Ag of the T. parva (Muguga) stock was obtained by using these mAb in a novel eukaryotic expression cloning system that allows isolation of cDNA encoding cytoplasmic or surface Ags. To establish the molecular basis of the polymorphism of PIM, the cDNA of the PIM Ag from a buffalo-derived T. parva stock was isolated and its sequence was compared with that of the cattle-derived Muguga PIM. The two cDNAs showed considerable identity in both the 5{prime} and 3{prime} regions, but there was substantial sequence divergence in the central regions. Several types of repeated sequences were identified in the variant regions. In the Muguga form of the molecule, there were five tandem repeats of the tetrapeptide, QPEP, that were shown, by transfection of a deleted version of the PIM gene, not to react with several anti-PIM mAbs. By isolating and sequencing the genomic version of the gene, we identified two small introns in the 3{prime} region of the gene. Finally, we showed that polyclonal rat Abs against recombinant PIM neutralize sporozoite infectivity in vitro, suggesting that the PIM Ag should be evaluated for its capacity to immunize cattle against East Coast Fever.

  19. Attenuated recombinant vaccinia virus expressing oncofetal antigen (tumor-associated antigen) 5T4 induces active therapy of established tumors.

    PubMed

    Mulryan, Kate; Ryan, Matthew G; Myers, Kevin A; Shaw, David; Wang, Who; Kingsman, Susan M; Stern, Peter L; Carroll, Miles W

    2002-10-01

    The human oncofetal antigen 5T4 (h5T4) is a transmembrane glycoprotein overexpressed by a wide spectrum of cancers, including colorectal, ovarian, and gastric, but with a limited normal tissue expression. Such properties make 5T4 an excellent putative target for cancer immunotherapy. The murine homologue of 5T4 (m5T4) has been cloned and characterized, which allows for the evaluation of immune intervention strategies in "self-antigen" in vivo tumor models. We have constructed recombinant vaccinia viruses based on the highly attenuated and modified vaccinia virus ankara (MVA strain), expressing h5T4 (MVA-h5T4), m5T4 (MVA-m5T4), and Escherichia coli LacZ (MVA-LacZ). Immunization of BALB/c and C57BL/6 mice with MVA-h5T4 and MVA-m5T4 constructs induced antibody responses to human and mouse 5T4, respectively. C57BL/6 and BALB/c mice vaccinated with MVA-h5T4 were challenged with syngeneic tumor line transfectants, B16 melanoma, and CT26 colorectal cells that express h5T4. MVA-h5T4-vaccinated mice showed significant tumor retardation compared with mice vaccinated with MVA-LacZ or PBS. In active treatment studies, inoculation with MVA-h5T4 was able to treat established CT26-h5T4 lung tumor and to a lesser extent B16.h5T4 s.c. tumors. Additionally, when C57BL/6 mice vaccinated with MVA-m5T4 were challenged with B16 cells expressing m5T4, resulting growth of the tumors was significantly retarded compared with control animals. Furthermore, mice vaccinated with MVA-m5T4 showed no signs of autoimmune toxicity. These data support the use of MVA-5T4 for tumor immunotherapy. PMID:12481437

  20. Effects of vector fusion peptides on the conformation and immune reactivity of epitope-shuffled, recombinant multi-epitope antigens.

    PubMed

    Wang, Jian; Lin, Yahui; Cai, Pengfei; Wang, Heng

    2011-01-01

    The use of multi-epitopes has been considered as a promising strategy to overcome the obstacle of antigenic variation in malarial vaccine development. Previously, we constructed a multi-epitope artificial antigen, Malaria Random Constructed Antigen-1(M.RCAg-1), to optimize expression of the antigen, and we subcloned the gene into three prokaryotic expression vectors that contain different fusion tags at the N-terminus. Three recombinant proteins expressed by these vectors, named M.RCAg-1/Exp.V-1, V-2, and V-3, were purified after the cleavage of the fusion tag. All three recombinant proteins were able to induce similar levels of antigenicity in BALB/c murine models. However, the antibody responses against the individual epitope peptides of the recombinant products were dramatically different. Additionally, the different epitopes elicited various CD4(+) T-cell responses, as shown by the resulting lymphocyte proliferation and varied IFN-γ and IL-4 levels determined by EILSPOT; however, each could be distinctly recognized by sera derived from malaria patients. Additionally, the rabbit antibody induced by these proteins showed diverse efficacy in malaria parasite growth inhibition assays in vitro. Furthermore, analysis via circular dichroism spectroscopy confirmed that the secondary structure was different among these recombinant proteins. These results suggest that the expressed multi-epitope artificial antigens originating from the different vector fusion peptides indeed affect the protein folding and, subsequently, the epitope exposure. Thus, these proteins are able to induce both distinct humoral and cellular immune responses in animal models, and they affect the efficacy of immune inhibition against the parasite. This work should lead to a further understanding of the impact of vector fusion peptides on the conformation and immune reactivity of recombinant proteins and could provide a useful reference for the development of artificial multi-epitope vaccines. PMID

  1. 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. PMID:25787135

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

    PubMed Central

    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

    2015-01-01

    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. PMID:25787135

  3. Oral immunization of fish against iridovirus infection using recombinant antigen produced from rice callus.

    PubMed

    Shin, Y J; Kwon, T H; Seo, J Y; Kim, T J

    2013-10-25

    Fish iridoviruses cause systemic diseases with high morbidity and mortality in various species of wild and farm-raised fish, resulting in severe economic losses, and no large-scale protective vaccine program or therapy is currently available. In this study, we expressed a recombinant major capsid protein (rMCP) of rock bream iridovirus in transgenic rice callus. The rMCP in lyophilized rice callus powder was added to feed to induce intestinal mucosal immunity for protection against and/or to reduce the severity of the iridovirus infection. We found that fish (Rock bream) immunized orally with rMCP underwent successful induction of antibodies (P<0.05) and were protected (P<0.001) against viral challenge. These results suggest that oral administration of rMCP as an antigen is a useful method to implement a vaccine program against iridovirus and other marine viral diseases. PMID:24021312

  4. Vaccination with Brucella abortus recombinant in vivo-induced antigens reduces bacterial load and promotes clearance in a mouse model for infection.

    PubMed

    Lowry, Jake E; Isaak, Dale D; Leonhardt, Jack A; Vernati, Giulia; Pate, Jessie C; Andrews, Gerard P

    2011-01-01

    Current vaccines used for the prevention of brucellosis are ineffective in inducing protective immunity in animals that are chronically infected with Brucella abortus, such as elk. Using a gene discovery approach, in vivo-induced antigen technology (IVIAT) on B. abortus, we previously identified ten loci that encode products up-regulated during infection in elk and consequently may play a role in virulence. In our present study, five of the loci (D15, 0187, VirJ, Mdh, AfuA) were selected for further characterization and compared with three additional antigens with virulence potential (Hia, PrpA, MltA). All eight genes were PCR-amplified from B. abortus and cloned into E. coli. The recombinant products were then expressed, purified, adjuvanted, and delivered subcutaneously to BALB/c mice. After primary immunization and two boosts, mice were challenged i.p. with 5 x 10⁴ CFU of B. abortus strain 19. Spleens from challenged animals were harvested and bacterial loads determined by colony count at various time points. While vaccination with four of the eight individual proteins appeared to have some effect on clearance kinetics, mice vaccinated with recombinant Mdh displayed the most significant reduction in bacterial colonization. Furthermore, mice immunized with Mdh maintained higher levels of IFN-γ in spleens compared to other treatment groups. Collectively, our in vivo data gathered from the S19 murine colonization model suggest that vaccination with at least three of the IVIAT antigens conferred an enhanced ability of the host to respond to infection, reinforcing the utility of this methodology for the identification of potential vaccine candidates against brucellosis. Mechanisms for immunity to one protein, Mdh, require further in vitro exploration and evaluation against wild-type B. abortus challenge in mice, as well as other hosts. Additional studies are being undertaken to clarify the role of Mdh and other IVI antigens in B. abortus virulence and induction of

  5. Evidence of Localized Prophage-Host Recombination in the lytA Gene, Encoding the Major Pneumococcal Autolysin ▿

    PubMed Central

    Morales, María; García, Pedro; de la Campa, Adela G.; Liñares, Josefina; Ardanuy, Carmen; García, Ernesto

    2010-01-01

    According to a highly polymorphic region in the lytA gene, encoding the major autolysin of Streptococcus pneumoniae, two different families of alleles can be differentiated by PCR and restriction digestion. Here, we provide evidence that this polymorphic region arose from recombination events with homologous genes of pneumococcal temperate phages. PMID:20304992

  6. Successful immunization of naturally reared pigs against porcine cysticercosis with a recombinant oncosphere antigen vaccine

    PubMed Central

    Jayashi, César M.; Kyngdon, Craig T.; Gauci, Charles G.; Gonzalez, Armando E.; Lightowlers, Marshall W.

    2012-01-01

    Taenia solium causes cysticercosis in pigs and taeniasis and neurocysticercosis in humans. Oncosphere antigens have proven to be effective as vaccines to protect pigs against an experimental infection with T. solium. A pair-matched vaccination trial field, using a combination of two recombinant antigens, TSOL16 and TSOL18, was undertaken in rural villages of Peru to evaluate the efficacy of this vaccine under natural conditions. Pairs of pigs (n = 137) comprising one vaccinated and one control animal, were allocated to local villagers. Animals received two vaccinations with 200 μg of each of TSOL16 and TSOL18, plus 5 mg Quil-A. Necropsies were performed 7 months after the animals were distributed to the farmers. Vaccination reduced 99.7% and 99.9% (p < 0.01) the total number of cysts and the number of viable cysts, respectively. Immunization with the TSOL16–TSOL18 vaccines has the potential to control T. solium transmission in areas where the disease is endemic, reducing the source for tapeworm infections in humans. PMID:22541797

  7. Alveolar Echinococcosis: Characterization of Diagnostic Antigen Em18 and Serological Evaluation of Recombinant Em18

    PubMed Central

    Sako, Yasuhito; Nakao, Minoru; Nakaya, Kazuhiro; Yamasaki, Hiroshi; Gottstein, Bruno; Lightowers, Marshall W.; Schantz, Peter M.; Ito, Akira

    2002-01-01

    The Echinococcus multilocularis protein Em18 is one of the most promising antigens for use in serodiagnosis of alveolar echinococcosis in human patients. Here we identify an antigenic relationship between Em18 and a 65-kDa immunodominant E. multilocularis surface protein previously identified as either EM10 or EmII/3. The NH2-terminal sequence of native Em18 was determined, revealing it to be a fragment of EM10. Experiments were undertaken to investigate the effect of proteinase inhibitors on the degradation of EM10 in crude extracts of E. multilocularis protoscoleces. Em18 was found to be the product of degradation of EM10 by cysteine proteinase. A recombinant Em18 (RecEm18, derived from 349K to 508K of EM10) was successfully expressed by using Escherichia coli expression system and then evaluated for use in serodiagnosis of alveolar echinococcosis. RecEm18 was recognized by 27 (87.1%) and 28 (90.3%) of 31 serum samples from clinically and/or pathologically confirmed alveolar echinococcosis patients by enzyme-linked immunosorbent assay and immunoblotting, respectively. Of 33 serum samples from cystic echinococcosis patients, 1 was recorded as having a weak positive reaction to RecEm18; however, none of the serum samples which were tested from neurocysticercosis patients (n = 10) or healthy people (n = 15) showed positive reactions. RecEm18 has the potential for use in the differential serodiagnosis of alveolar echinococcosis. PMID:12149326

  8. pap-2-encoded fimbriae adhere to the P blood group-related glycosphingolipid stage-specific embryonic antigen 4 in the human kidney.

    PubMed Central

    Karr, J F; Nowicki, B J; Truong, L D; Hull, R A; Moulds, J J; Hull, S I

    1990-01-01

    A subtype of P fimbriae, encoded by the pap-2 gene cluster, has been analyzed for agglutination of erythrocytes and for binding to cryostat sections of the human kidney. We have demonstrated that pap-2-encoded fimbriae are capable of binding to erythrocytes from some animal species and to human erythrocytes which express globoside and the LKE (stage-specific embryonic antigen 4 [SSEA-4]) antigen. The pap-2 fimbriae bind to Bowman's capsule in the human kidney. Monoclonal antibodies directed against glycosphingolipids were used for the detection of specific P blood group-related antigens in the human kidney and on erythrocytes. Preincubation of kidney sections with monoclonal antibody MC813-70, which binds to the SSEA-4 antigen, inhibited adherence of purified pap-2-encoded fimbriae to Bowman's capsule. We suggest that one receptor for pap-2-encoded fimbriae is the antigen known as LKE (Luke) on human erythrocytes or SSEA-4 in the tissues. Images PMID:1979319

  9. Protective immune responses of recombinant VP2 subunit antigen of infectious bursal disease virus in chickens.

    PubMed

    Pradhan, Satya Narayan; Prince, Prabhu Rajaiah; Madhumathi, Jayaprakasam; Roy, Parimal; Narayanan, Rangarajan Badri; Antony, Usha

    2012-08-15

    Infectious bursal disease virus (IBDV) is the causative agent of Gumboro disease and poses a huge threat to poultry industry. The risks associated with conventional attenuated viral vaccines make it indispensable to probe into the development of novel and rationally designed subunit vaccines which are safer as well as effective. VP2 is the major host-protective antigen found in IBDV capsid. It encompasses different independent epitopes responsible for the induction of neutralizing antibody. Here, we report the efficacy of the immunodominant fragment of VP2 which induces both humoral and cellular immunity against infectious bursal disease. A 366 bp fragment (52-417 bp) of the VP2 gene from an IBDV field isolate was amplified and expressed in Escherichia coli as a 21 kDa recombinant protein. The efficacy of rVP2(52-417) antigen was compared with two commercial IBDV whole virus vaccine strains. The rVP2(52-417) induced significantly high antibody titres in chicken compared to commercial vaccines and the anti-rVP2(52-417) sera showed reactivity with viral antigens from both commercial strains (P<0.0001) and field isolates. Also, the chicken splenocytes from rVP2(52-417) immunized group showed a significantly high proliferation (P<0.01) compared to other groups, which implies that the rVP2(52-417) fragment contains immunogenic epitopes capable of eliciting both B and T cell responses. Further, rVP2(52-417) conferred 100% protection against vIBDV challenge in the immunized chickens which was significantly higher (P<0.001) compared to 55-60% protection by commercial vaccine strains. Hence, the study confirms the efficacy of the immunodominant VP2 fragment that could be used as a potent vaccine against IBDV infection in chicken. PMID:22795186

  10. Immunoblot assays using recombinant antigens for the detection of Mycoplasma hyopneumoniae antibodies.

    PubMed

    Subramaniam, S; Frey, J; Huang, B; Djordjevic, S; Kwang, J

    2000-07-01

    The 36kDa L-lactate dehydrogenase (LDH) and a 29kDa partial fragment of an ABC transporter ATP-binding protein analogue/multidrug resistance protein homologue (PR2) of Mycoplasma hyopneumoniae were tested for their potential as diagnostic antigens. Recombinant LDH was genetically engineered to contain six histidine residues at its C-terminal end, expressed in Escherichia coli and purified to a high degree using Ni(2+)-chelate affinity chromatography. A partial 262 amino acid segment representing the C-terminal end of the PR2 protein was cloned as a glutathione S-transferase (GST) fusion protein, expressed in E. coli and purified by urea extraction. Purified recombinant LDH-6xHis and PR2-GST were then reacted with pig sera in immunoblot assays. Our immunoblots showed that both proteins detected anti-M. hyopneumoniae antibodies in field and experimentally infected pig sera but not in any of the SPF control sera. The two proteins were specific for M. hyopneumoniae as they did not react with sera of pigs infected with the closely related Mycoplasma flocculare and Mycoplasma hyorhinis which are frequently isolated in pigs but are not of particular concern. PMID:10865156

  11. Recombinant antigen-based enzyme immunoassay for screening of Treponema pallidum antibodies in blood bank routine.

    PubMed Central

    Zrein, M; Maure, I; Boursier, F; Soufflet, L

    1995-01-01

    This work reports a comparison of an enzyme immunoassay (EIA) using two major Treponema pallidum recombinant antigens with a T. pallidum hemagglutination (TPHA) assay and a nontreponemal Venereal Disease Reference Laboratory (VDRL) test. A total of 1,822 normal donor serum samples was tested for cardiolipin and T. pallidum antibodies, respectively, by the VDRL assay and EIA. Among these samples, 440 were further tested by TPHA technology. Four samples were found positive by EIA, while all were reported to be negative by both TPHA and VDRL routine assays. Subsequent testing of EIA-positive samples confirmed 100% (four of four samples) and 25% (one of four samples) positive results, respectively, by immunofluorescence assay and a Western blot (immunoblot) syphilis kit. The sensitivity of the recombinant EIA was estimated at virtually 100% with a reference panel of 50 syphilitic samples. According to this study, the newly developed EIA kit shows 100% sensitivity combined to a specificity greater than 99.8% for detecting treponemal immunoglobulin G antibodies in blood bank syphilis screening. PMID:7751351

  12. Control of Boophilus microplus populations in grazing cattle vaccinated with a recombinant Bm86 antigen preparation.

    PubMed

    Rodríguez, M; Penichet, M L; Mouris, A E; Labarta, V; Luaces, L L; Rubiera, R; Cordovés, C; Sánchez, P A; Ramos, E; Soto, A

    1995-04-01

    Current methods for the control of cattle tick Boophilus microplus infestations are not effective and the parasite remains a serious problem for the cattle industry in tropical and subtropical areas. Recently, we developed a vaccine against B. microplus employing a recombinant Bm86 (rBm86) antigen preparation (Gavac, Heber Biotec) and it was shown to induce a protective response in vaccinated animals under controlled conditions. Here we show that, under field conditions in grazing cattle, the vaccine is able to control B. microplus populations. Two parasite-free farms were employed for the study. In the first farm, animals were vaccinated with the recombinant vaccine, while, in the second, animals received a saline injection in adjuvant. After immunization, animals were artificially infected and the infestation rate was recorded. Over the 33 weeks of the experiment, the infestation rate was lower in the vaccinated group compared with the control group. At the end of the experiment it was necessary to use chemicals in the control farm after serious losses in production and animals. PMID:7660571

  13. Serotype, antigenicity, and pathogenicity of a naturally recombinant TW I genotype infectious bronchitis coronavirus in China.

    PubMed

    Gao, Mengying; Wang, Qiuling; Zhao, Wenjun; Chen, Yuqiu; Zhang, Tingting; Han, Zongxi; Xu, Qianqian; Kong, Xiangang; Liu, Shengwang

    2016-08-15

    Since 2009, strains of the naturally recombinant TW I genotype of infectious bronchitis virus (IBV) have caused considerable damage to the Chinese poultry industry. To better understand the antigenicity and pathogenesis of this genotype, the characteristics of the ck/CH/LDL/140520 strain were compared to those of four commercial IB vaccine strains that are used commonly in China, as well as four attenuated viruses that represent two types of IBV strains, which are believed to have originated in China and are the predominant IBV types circulating in chicken flocks in China and many other parts of the world. The results showed that all eight strains were genetically and serotypically different from the strain ck/CH/LDL/140520. Furthermore, neither the vaccine strains nor the attenuated viruses could provide complete respiratory protection of chickens against a challenge with the ck/CH/LDL/140520 strain, indicating that it is necessary to develop new live vaccines or to evaluate the use of established vaccines in combination to control naturally recombinant TW I-type IBV strains in the future. Our results showed that strain ck/CH/LDL/140520 is very pathogenic, and that it is able to cause cystic oviducts in a high percentage of birds, as well as mortality due to nephritis and respiratory distress with complete tracheal ciliostasis, especially in chickens infected at 1day of age. PMID:27374900

  14. Rational engineering of recombinant picornavirus capsids to produce safe, protective vaccine antigen.

    PubMed

    Porta, Claudine; Kotecha, Abhay; Burman, Alison; Jackson, Terry; Ren, Jingshan; Loureiro, Silvia; Jones, Ian M; Fry, Elizabeth E; Stuart, David I; Charleston, Bryan

    2013-03-01

    Foot-and-mouth disease remains a major plague of livestock and outbreaks are often economically catastrophic. Current inactivated virus vaccines require expensive high containment facilities for their production and maintenance of a cold-chain for their activity. We have addressed both of these major drawbacks. Firstly we have developed methods to efficiently express recombinant empty capsids. Expression constructs aimed at lowering the levels and activity of the viral protease required for the cleavage of the capsid protein precursor were used; this enabled the synthesis of empty A-serotype capsids in eukaryotic cells at levels potentially attractive to industry using both vaccinia virus and baculovirus driven expression. Secondly we have enhanced capsid stability by incorporating a rationally designed mutation, and shown by X-ray crystallography that stabilised and wild-type empty capsids have essentially the same structure as intact virus. Cattle vaccinated with recombinant capsids showed sustained virus neutralisation titres and protection from challenge 34 weeks after immunization. This approach to vaccine antigen production has several potential advantages over current technologies by reducing production costs, eliminating the risk of infectivity and enhancing the temperature stability of the product. Similar strategies that will optimize host cell viability during expression of a foreign toxic gene and/or improve capsid stability could allow the production of safe vaccines for other pathogenic picornaviruses of humans and animals. PMID:23544011

  15. Use of replication restricted recombinant vesicular stomatitis virus vectors for detection of antigen-specific T cells.

    PubMed

    Moseley, Nelson B; Laur, Oskar; Ibegbu, Chris C; Loria, Gilbert D; Ikwuenzunma, Gini; Jayakar, Himangi R; Whitt, Michael A; Altman, John D

    2012-01-31

    Detection of antigen-specific T cells at the single-cell level by ELISpot or flow cytometry techniques employing intracellular cytokine staining (ICS) is now an indispensable tool in many areas of immunology. When precisely mapped, optimal MHC-binding peptide epitopes are unknown, these assays use antigen in a variety of forms, including recombinant proteins, overlapping peptide sets representing one or more target protein sequences, microbial lysates, lysates of microbially-infected cells, or gene delivery vectors such as DNA expression plasmids or recombinant vaccinia or adenoviruses expressing a target protein of interest. Here we introduce replication-restricted, recombinant vesicular stomatitis virus (VSV) vectors as a safe, easy to produce, simple to use, and highly effective vector for genetic antigen delivery for the detection of human antigen-specific helper and cytotoxic T cells. To demonstrate the broad applicability of this approach, we have used these vectors to detect human T cell responses to the immunodominant pp65 antigen of human cytomegalovirus, individual segments of the yellow fever virus polyprotein, and to various influenza proteins. PMID:22004852

  16. Purification of recombinant Helicobacter pylori urease apoenzyme encoded by ureA and ureB.

    PubMed

    Hu, L T; Foxall, P A; Russell, R; Mobley, H L

    1992-07-01

    Helicobacter pylori, a gram-negative, microaerophilic, spiral-shaped bacterium, is an etiologic agent of human gastritis and peptic ulceration and is highly restricted to the gastric mucosa of humans. Urease, synthesized at up to 6% of the soluble cell protein, hydrolyzes urea, thereby releasing ammonia, which may neutralize acid, allowing survival of the bacterium and initial colonization of the gastric mucosa. The urease protein is encoded by two subunit genes, ureA and ureB; however, accessory genes are necessary for enzyme activity. H. pylori urease genes were isolated from a cosmid gene bank and subcloned on a 5.8-kb Sau3A partial fragment carrying ureCDAB, corresponding to four open reading frames described by A. Labigne, V. Cussac, and P. Courcoux (J. Bacteriol. 173:1920-1931, 1991). Clones were confirmed as ureas gene sequences by polymerase chain reaction amplification. The recombinant enzyme was purified from the soluble protein of French press lysates of Escherichia coli DH5 alpha(pHP402) by chromatography on DEAE-Sepharose, Phenyl-Sepharose, Mono-Q, and Superose 6 resins. Fractions containing a catalytically inactive apoenzyme were identified by an enzyme-linked immunosorbent assay (ELISA) by using antisera to native UreA (29.5 kDa) and UreB (66 kDa). Purified recombinant urease was indistinguishable from native enzyme on a Superose 6 column and on Coomassie blue-stained sodium dodecyl sulfate-polyacrylamide gels. The protein reacted specifically on Western blots (immunoblots) with anti-UreA and anti-UreB antibodies and was recognized with an intensity equal to that of the native enzyme in an ELISA using human sera. Clones containing only ureA and ureB also produced an assembled but inactive enzyme. Enzyme activity was not restored by in trans complementation with cloned urease accessory gene sequences from Proteus mirabilis or Morganella morganii. H. pylori urease genes (ureCDAB) subcloned into pACYC184 were also not complemented with any of 1

  17. Expression of MPB83 from Mycobacterium bovis in Brucella abortus S19 induces specific cellular immune response against the recombinant antigen in BALB/c mice.

    PubMed

    Sabio y García, Julia V; Bigi, Fabiana; Rossetti, Osvaldo; Campos, Eleonora

    2010-12-01

    Immunodominant MPB83 antigen from Mycobacterium bovis was expressed as a chimeric protein fused to either β-galactosidase, outer membrane lipoprotein OMP19 or periplasmic protein BP26 in gram-negative Brucella abortus S19, in all cases driven by each gene's own promoter. All fusion proteins were successfully expressed and localized in the expected subcellular fraction. Moreover, OMP19-MPB83 was processed as a lipoprotein when expressed in B. abortus. Splenocytes from BALB/c mice immunized with the recombinant S19 strains carrying the genes coding for the heterologous antigens in replicative plasmids, showed equally specific INF-γ production in response to MPB83 stimulation. Association to the lipid moiety of OMP19 presented no advantage in terms of immunogenicity for MPB83. In contrast, fusion to BP26, which was encoded by an integrative plasmid, resulted in a weaker immune response. None of the constructions affected the survival rate or the infection pattern of Brucella. We concluded that B. abortus S19 is an appropriate candidate for the expression of M. bovis antigens both associated to the membrane or cytosolic fraction and may provide the basis for a future combined vaccine for bovine brucellosis and tuberculosis. PMID:20888425

  18. Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites

    PubMed Central

    Sima, Michal; Ferencova, Blanka; Warburg, Alon; Rohousova, Iva; Volf, Petr

    2016-01-01

    Background Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs) using salivary gland homogenates (SGHs) as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replacement of SGH with recombinant salivary proteins. In East Africa, Phlebotomus orientalis is the main vector of Leishmania donovani, a trypanosomatid parasite causing visceral leishmaniasis. We tested recombinant salivary proteins derived from Ph. orientalis saliva to study exposure of domestic animals to this sand fly species. Methodology/Principal Findings Antigenic salivary proteins from Ph. orientalis were identified by immunoblot and mass spectrometry. Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. orientalis is present. Our results highlighted recombinant yellow-related protein rPorSP24 as the most promising antigen, displaying a high positive correlation coefficient as well as good sensitivity and specificity when compared to SGH. This recombinant protein was the most suitable one for testing sera of dogs, sheep, and goats. In addition, a different antigen, rPorSP65 was found efficacious for testing canine sera. Conclusions/Significance Recombinant salivary proteins of Ph. orientalis, specifically rPorSP24, were shown to successfully substitute SGH in serological experiments to measure exposure of domestic animals to Ph. orientalis, the vector of L. donovani. The results suggest that rPorSP24 might be a suitable antigen for detecting anti-Ph. orientalis antibody

  19. Characterization of a specific Mycobacterium paratuberculosis recombinant clone expressing 35,000-molecular-weight antigen and reactivity with sera from animals with clinical and subclinical Johne's disease.

    PubMed Central

    El-Zaatari, F A; Naser, S A; Graham, D Y

    1997-01-01

    Johne's disease is a chronic enteritis of ruminants associated with enormous worldwide economic losses for the dairy cow- and goat-rearing industries. Management limitations and eradication programs for this disease have been hampered by the lack of a simple and specific diagnostic test for the detection of subclinical cases. We used a recombinant clone expressing a 35,000-molecular-weight Mycobacterium paratuberculosis antigen (p35 antigen) from a previously constructed expression library of M. paratuberculosis in Escherichia coli. The DNA fragment encoding the p35 gene hybridized only to DNA from Mycobacterium avium complex, but not to DNAs from other mycobacteria and nonmycobacterial organisms. The seroreactivity of p35 was evaluated by immunoblotting against 57 reference serum samples obtained from infected and uninfected animals. p35 was recognized by sera from 100% of animals with advanced Johne's disease (clinical stage) (12 cattle, 2 goats, and 2 sheep) and by sera from 75% of 20 cattle with early infection (subclinical stage). None of the sera from 15 M. paratuberculosis-free cows, 3 Mycobacterium bovis BCG-infected tuberculous cattle, or 3 cows artificially inoculated with multiple doses of viable M. paratuberculosis reacted with p35. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 86, 100, 100, and 75%, respectively. The accuracy of p35 immunoblotting was superior to those of commercially available diagnostic tests for Johne's disease. These results suggest that the p35 recombinant protein has potential for use in the serodiagnosis of animals with Johne's disease at all stages of infection. The DNA fragment encoding p35 may also serve as a probe for identification of M. avium complex infection. PMID:9196196

  20. High-level expression of recombinant dengue viral NS-1 protein and its potential use as a diagnostic antigen.

    PubMed

    Huang, J L; Huang, J H; Shyu, R H; Teng, C W; Lin, Y L; Kuo, M D; Yao, C W; Shaio, M F

    2001-11-01

    The prevalence of NS1 Ab response in patients with dengue viral infection and the potential of using recombinant NS1 protein as a diagnostic antigen for dengue viral infection were investigated. In this study, the full-length and C-terminal half of NS1 proteins (rNS1, rNS1-C) were highly expressed (10-30 mg/l) and further purified and refolded. The good antigenicity of the full-length rNS1 protein was confirmed by interaction with 19 dengue NS1-specific monoclonal antibodies (MAbs) in ELISA; however, the antigenicity of rNS1-C was relatively lower. The full-length rNS1 antigen also differentiated reliably between sera from dengue virus-infected patients and sera from normal controls. When rNS1 was used as an antigen to detect human anti-NS1 IgM and IgG Ab, the anti-NS1 Ab response was found in 15 of 17 patients (88%) with primary dengue infection and all 16 patients (100%) with secondary dengue infection. These results indicated that using the full-length rNS1 whose antigenicity is restored as ELISA antigen, a high anti-NS1 antibody prevalence could be detected in patients with either primary or secondary dengue infection. This finding suggested that the anti-NS1 antibody appeared not only in secondary and severe dengue virus infection and might not correlate the pathogenesis of dengue hemorrhagic fever. The study also verified that our purified rNS1 protein showed similar immunological properties as native dengue viral proteins. Genetic engineering production of recombinant NS1 antigen could provide a safe and valuable resource for dengue virus serodiagnosis. PMID:11596093

  1. Recombinant Secreted Antigens from Mycoplasma hyopneumoniae Delivered as a Cocktail Vaccine Enhance the Immune Response of Mice

    PubMed Central

    Galli, Vanessa; Simionatto, Simone; Marchioro, Silvana Beutinger; Klabunde, Gustavo Henrique Ferrero; Conceição, Fabricio Rochedo

    2013-01-01

    Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia (EP), which is a respiratory disease responsible for huge economic losses in the pig industry worldwide. The commercially available vaccines provide only partial protection and are expensive. Thus, the development of alternatives for the prophylaxis of EP is critical for improving pig health. The use of multiple antigens in the same immunization may represent a promising alternative. In the present study, seven secreted proteins of M. hyopneumoniae were cloned, expressed in Escherichia coli, and evaluated for antigenicity using serum from naturally and experimentally infected pigs. In addition, the immunogenicity of the seven recombinant proteins delivered individually or in protein cocktail vaccines was evaluated in mice. In Western blot assays and enzyme-linked immunosorbent assays, most of the recombinant proteins evaluated were recognized by convalescent-phase serum from the animals, indicating that they are expressed during the infectious process. The recombinant proteins were also immunogenic, and most induced a mixed IgG1/IgG2a humoral immune response. The use of these proteins in a cocktail vaccine formulation enhanced the immune response compared to their use as antigens delivered individually, providing evidence of the efficacy of the multiple-antigen administration strategy for the induction of an immune response against M. hyopneumoniae. PMID:23803903

  2. Targeting TARP, a novel breast and prostate tumor-associated antigen, with T-cell receptor- like human recombinant antibodies

    PubMed Central

    Epel, Malka; Carmi, Irit; Soueid- Baumgarten, Sharon; Oh, SangKon; Bera, Tapan; Pastan, Ira; Berzofsky, Jay; Reiter, Yoram

    2009-01-01

    MHC class I molecules are important components of immune surveillance. There are no available methods to directly visualize and determine the quantity and distribution of MHC/peptide complexes on individual cells or to detect such complexes on antigen presenting cells in tissues. MHC-restricted recombinant antibodies with the same specificity of T-cell receptors may become a valuable tool to address these questions. They may also serve as valuable targeting molecules that mimic the specificity of cytotoxic T cells. We isolated by phage display a panel of human recombinant Fab antibodies with peptide-specific, MHC-restricted TCR-like reactivity directed toward HLA-A2-restricted T-cell epitope derived from a novel antigen termed TCRγ Alternative Reading frame Protein (TARP) which is expressed on prostate and breast cancer cells. We have characterized one of these recombinant antibodies and demonstrated its capacity to directly detect specific HLA-A2/TARP T-cell epitopes on antigen presenting cells that have complexes formed by naturally occurring active intracellular processing of the antigen as well as on the surface of tumor cells. Moreover, by genetic fusion we armed the TCR-like antibody with a potent toxin and demonstrated that it can serve as a targeting moiety killing tumor cells in a peptide-specific, MHC-restricted manner similar to cytotoxic T-cell Lymphocytes. PMID:18446790

  3. Antigen

    MedlinePlus

    An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune ... and is trying to fight it off. An antigen may be a substance from the environment, such ...

  4. Reactivity of dog sera to whole-cell or recombinant antigens of Borrelia burgdorferi by ELISA and immunoblot analysis.

    PubMed

    Magnarelli, L A; Levy, S A; Ijdo, J W; Wu, C; Padula, S J; Fikrig, E

    2001-10-01

    Enzyme-linked immunosorbent assays (ELISAs) with separate preparations of 10 purified recombinant antigens of Borrelia burgdorferi sensu stricto were used to test sera from 36 dogs not vaccinated with whole cells of this agent and from five dogs vaccinated with whole-cell B. burgdorferi bacteria. All dogs lived in tick-infested areas of Connecticut and south-eastern New York state, USA. The non-vaccinated dogs had limb or joint disorder, lameness and fever during the period 1984-1991 and had antibodies to B. burgdorferi, as determined by a polyvalent ELISA with whole-cell antigen. In re-analyses of sera for total immunoglobulins in ELISAs with recombinant antigens, reactions were most frequently recorded when outer-surface protein (Osp) F, protein (p)35, p37, p39 and p-41G (a flagellin component) were tested separately. Western immunoblots of a subset of 16 sera, positive by ELISA with whole-cell antigen and representing a range of antibody titres (640-40960), verified immune responses to these or other lysed whole-cell antigens. Sera from vaccinated dogs contained antibodies to OspA, OspB, p22, p37 and p41-G. Therefore, serological reactions to OspF, p35 and p39 were the most important indicators of natural exposure to B. burgdorferi. Serum reactivities to these recombinant antigens in ELISAs can be used to help identify possible natural infections of canine borreliosis in dogs not vaccinated with whole-cell B. burgdorferi and to provide information on the geographic distribution of this bacterium. PMID:11599738

  5. Small-angle neutron scattering study of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle

    NASA Astrophysics Data System (ADS)

    Sato, M.; Ito, Y.; Kameyama, K.; Imai, M.; Ishikawa, N.; Takagi, T.

    1995-02-01

    The overall and internal structure of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particles was investigated by small-angle neutron scattering using the contrast variation method. The vaccine is a nearly spherical particle, and its contrast-matching point was determined to be at about 24% D 2O content, indicating that a large part of the vaccine particle is occupied by lipids and carbohydrates from the yeast. The Stuhrmann plot suggests that the surface antigens exist predominantly in the peripheral region of the particle, which is favorable to the induction of anti-virus antibodies.

  6. Evaluation of Recombinant Leptospira Antigen-Based Enzyme-Linked Immunosorbent Assays for the Serodiagnosis of Leptospirosis

    PubMed Central

    Flannery, Brendan; Costa, Dirceu; Carvalho, Fernanda Pinheiro; Guerreiro, Hygia; Matsunaga, James; Da Silva, Emilson Domingos; Ferreira, Antonio Gomes Pinto; Riley, Lee W.; Reis, Mitermayer G.; Haake, David A.; Ko, Albert I.

    2001-01-01

    There is an urgent need for development of new serodiagnostic strategies for leptospirosis, an emerging zoonosis with worldwide distribution. We have evaluated the diagnostic utility of five recombinant antigens in enzyme-linked immunosorbent assays (ELISAs) for serodiagnosis of leptospirosis. Sera from 50 healthy residents of a high-incidence region were used to determine cutoff values for 96% specificity. In paired sera from 50 cases of leptospirosis confirmed by the microscopic agglutination test, immunoglobulin G (IgG) but not IgM reacted with the recombinant leptospiral proteins. The recombinant LipL32 IgG ELISA had the highest sensitivities in the acute (56%) and convalescent (94%) phases of leptospirosis. ELISAs based on recombinant OmpL1, LipL41, and Hsp58 had sensitivities of 16, 24, and 18% during the acute phase and 72, 44, and 32% during convalescence, respectively. Compared to sera from healthy individuals, patient sera did not react significantly with recombinant LipL36 (P > 0.05). Recombinant LipL32 IgG ELISA demonstrated 95% specificity among 100 healthy individuals, and specificities ranging from 90 to 97% among 30 dengue patients, 30 hepatitis patients, and 16 patients with diseases initially thought to be leptospirosis. Among 39 Venereal Disease Research Laboratory test-positive individuals and 30 Lyme disease patients, 13 and 23% of sera, respectively, reacted positively with the rLipL32 antigen. These findings indicate that rLipL32 may be an useful antigen for the serodiagnosis of leptospirosis. PMID:11526167

  7. ERCC4 (XPF) encodes a human nucleotide excision repair protein with eukaryotic recombination homologs.

    PubMed

    Brookman, K W; Lamerdin, J E; Thelen, M P; Hwang, M; Reardon, J T; Sancar, A; Zhou, Z Q; Walter, C A; Parris, C N; Thompson, L H

    1996-11-01

    ERCC4 is an essential human gene in the nucleotide excision repair (NER) pathway, which is responsible for removing UV-C photoproducts and bulky adducts from DNA. Among the NER genes, ERCC4 and ERCC1 are also uniquely involved in removing DNA interstrand cross-linking damage. The ERCC1-ERCC4 heterodimer, like the homologous Rad10-Rad1 complex, was recently found to possess an endonucleolytic activity that incises on the 5' side of damage. The ERCC4 gene, assigned to chromosome 16p13.1-p13.2, was previously isolated by using a chromosome 16 cosmid library. It corrects the defect in Chinese hamster ovary (CHO) mutants of NER complementation group 4 and is implicated in complementation group F of the human disorder xeroderma pigmentosum. We describe the ERCC4 gene structure and functional cDNA sequence encoding a 916-amino-acid protein (104 kDa), which has substantial homology with the eukaryotic DNA repair and recombination proteins MEI-9 (Drosophila melanogaster), Rad16 (Schizosaccharomyces pombe), and Rad1 (Saccharomyces cerevisiae). ERCC4 cDNA efficiently corrected mutants in rodent NER complementation groups 4 and 11, showing the equivalence of these groups, and ERCC4 protein levels were reduced in mutants of both groups. In cells of an XP-F patient, the ERCC4 protein level was reduced to less than 5%, consistent with XPF being the ERCC4 gene. The considerable identity (40%) between ERCC4 and MEI-9 suggests a possible involvement of ERCC4 in meiosis. In baboon tissues, ERCC4 was expressed weakly and was not significantly higher in testis than in nonmeiotic tissues. PMID:8887684

  8. Antigenic Characterization of Recombinant Hemagglutinin Proteins Derived from Different Avian Influenza Virus Subtypes

    PubMed Central

    Mueller, Matthias; Renzullo, Sandra; Brooks, Roxann; Ruggli, Nicolas; Hofmann, Martin A.

    2010-01-01

    Since the advent of highly pathogenic variants of avian influenza virus (HPAIV), the main focus of avian influenza research has been the characterization and detection of HPAIV hemagglutinin (HA) from H5 and H7 subtypes. However, due to the high mutation and reassortation rate of influenza viruses, in theory any influenza strain may acquire increased pathogenicity irrespective of its subtype. A comprehensive antigenic characterization of influenza viruses encompassing all 16 HA and 9 neuraminidase subtypes will provide information useful for the design of differential diagnostic tools, and possibly, vaccines. We have expressed recombinant HA proteins from 3 different influenza virus HA subtypes in the baculovirus system. These proteins were used to generate polyclonal rabbit antisera, which were subsequently employed in epitope scanning analysis using peptide libraries spanning the entire HA. Here, we report the identification and characterization of linear, HA subtype-specific as well as inter subtype-conserved epitopes along the HA proteins. Selected subtype-specific epitopes were shown to be suitable for the differentiation of anti-HA antibodies in an ELISA. PMID:20140098

  9. Thermal Aggregation of Recombinant Protective Antigen: Aggregate Morphology and Growth Rate

    PubMed Central

    Belton, Daniel J.; Miller, Aline F.

    2013-01-01

    The thermal aggregation of the biopharmaceutical protein recombinant protective antigen (rPA) has been explored, and the associated kinetics and thermodynamic parameters have been extracted using optical and environmental scanning electron microscopies (ESEMs) and ultraviolet light scattering spectroscopy (UV-LSS). Visual observations and turbidity measurements provided an overall picture of the aggregation process, suggesting a two-step mechanism. Microscopy was used to examine the structure of aggregates, revealing an open morphology formed by the clustering of the microscopic aggregate particles. UV-LSS was used and developed to elucidate the growth rate of these particles, which formed in the first stage of the aggregation process. Their growth rate is observed to be high initially, before falling to converge on a final size that correlates with the ESEM data. The results suggest that the particle growth rate is limited by rPA monomer concentration, and by obtaining data over a range of incubation temperatures, an approach was developed to model the aggregation kinetics and extract the rate constants and the temperature dependence of aggregation. In doing so, we quantified the susceptibility of rPA aggregation under different temperature and environmental conditions and moreover demonstrated a novel use of UV spectrometry to monitor the particle aggregation quantitatively, in situ, in a nondestructive and time-resolved manner. PMID:23476645

  10. Local Production of Tumor Necrosis Factor Encoded by Recombinant Vaccinia Virus is Effective in Controlling Viral Replication in vivo

    NASA Astrophysics Data System (ADS)

    Sambhi, Sharan K.; Kohonen-Corish, Maija R. J.; Ramshaw, Ian A.

    1991-05-01

    Tumor necrosis factor (TNF) has pleiotropic effects on a wide variety of cell types. In vitro studies have demonstrated that TNF has antiviral properties and is induced in response to viral infections. However, a role for TNF in the antiviral immune response of the host has yet to be demonstrated. Here we describe the construction of and studies using a recombinant vaccinia virus that encodes the gene for murine TNF-α. By comparing the replication of and immune responses elicited by the TNF-encoding virus to a similarly constructed control virus, we hoped to observe immunobiological effects of TNF in the host. The in vivo experiments with this recombinant virus demonstrate that the localized production of TNF-α during a viral infection leads to the rapid and efficient clearance of the virus in normal mice and attenuates the otherwise lethal pathogenicity of the virus in immunodeficient animals. This attenuation occurs early in the infection (by postinfection hour 24) and is not due to the enhancement of cellular or antibody responses by the vaccinia virus-encoded TNF. This evidence suggests that attenuation of the recombinant virus is due to a direct antiviral effect of TNF on cells at the site of infection. Therefore, these results support the suggestion that TNF produced by immune cells may be an important effector mechanism of viral clearance in vivo.

  11. Recombinant baculoviruses as vectors for identifying proteins encoded by intron-containing members of complex multigene families.

    PubMed Central

    Iatrou, K; Meidinger, R G; Goldsmith, M R

    1989-01-01

    Using a transfer vector derived from Bombyx mori nuclear polyhedrosis virus (BmNPV), we have constructed recombinant baculoviruses that contain complete silk moth chorion chromosomal genes encoding high-cysteine proteins under the control of the polyhedrin promoter. Silk moth tissue culture cells infected with these recombinant viruses were found to contain abundant RNA sequences of sizes similar to those of the authentic chorion mRNAs. Chorion transcripts present in infected cells were initiated almost exclusively at the cap site of the polyhedrin start site. Primer extension and RNase protection experiments revealed that a considerable proportion of the resultant transcripts were spliced at the same sites as those utilized in follicular cells for the production of functional chorion mRNA. Electrophoretic analysis and immunoprecipitation of the proteins of host cells infected with the recombinant viruses revealed the presence of the corresponding chorion proteins. We conclude that baculovirus vectors can be used for expressing efficiently not only cDNAs or simple genes devoid of intervening sequences but also intron-containing chromosomal genes. Thus, recombinant baculoviruses offer a powerful alternative to hybrid-selected translation, particularly when the identification of proteins encoded by members of complex multigene families is required. Images PMID:2556701

  12. SARS coronavirus nucleocapsid immunodominant T-cell epitope cluster is common to both exogenous recombinant and endogenous DNA-encoded immunogens.

    PubMed

    Gupta, Vandana; Tabiin, Tani M; Sun, Kai; Chandrasekaran, Ananth; Anwar, Azlinda; Yang, Kun; Chikhlikar, Priya; Salmon, Jerome; Brusic, Vladimir; Marques, Ernesto T A; Kellathur, Srinivasan N; August, Thomas J

    2006-03-30

    Correspondence between the T-cell epitope responses of vaccine immunogens and those of pathogen antigens is critical to vaccine efficacy. In the present study, we analyzed the spectrum of immune responses of mice to three different forms of the SARS coronavirus nucleocapsid (N): (1) exogenous recombinant protein (N-GST) with Freund's adjuvant; (2) DNA encoding unmodified N as an endogenous cytoplasmic protein (pN); and (3) DNA encoding N as a LAMP-1 chimera targeted to the lysosomal MHC II compartment (p-LAMP-N). Lysosomal trafficking of the LAMP/N chimera in transfected cells was documented by both confocal and immunoelectron microscopy. The responses of the immunized mice differed markedly. The strongest T-cell IFN-gamma and CTL responses were to the LAMP-N chimera followed by the pN immunogen. In contrast, N-GST elicited strong T cell IL-4 but minimal IFN-gamma responses and a much greater antibody response. Despite these differences, however, the immunodominant T-cell ELISpot responses to each of the three immunogens were elicited by the same N peptides, with the greatest responses being generated by a cluster of five overlapping peptides, N76-114, each of which contained nonameric H2d binding domains with high binding scores for both class I and, except for N76-93, class II alleles. These results demonstrate that processing and presentation of N, whether exogenously or endogenously derived, resulted in common immunodominant epitopes, supporting the usefulness of modified antigen delivery and trafficking forms and, in particular, LAMP chimeras as vaccine candidates. Nevertheless, the profiles of T-cell responses were distinctly different. The pronounced Th-2 and humoral response to N protein plus adjuvant are in contrast to the balanced IFN-gamma and IL-4 responses and strong memory CTL responses to the LAMP-N chimera. PMID:16387339

  13. Development and validation of an ELISA using a protein encoded by ORF2 antigenic domain of porcine circovirus type 2

    PubMed Central

    2010-01-01

    Background The capsid protein (ORF2) is a major structural protein of porcine circovirus type 2 (PCV2). A simple and reliable diagnostic method based on ORF2 protein immunoreactivity would serve as a valuable diagnostic method for detecting serum antibodies to PCV2 and monitoring PCV infection. Here, we reported an indirect enzyme-linked immunosorbent assay (I-ELISA) by using an antigenic domain (113-147AA) of ORF2-encoded antigen, expressed in E. coli, for diagnosis of PCV infection. Results The ELISA was performed on 288 serum samples collected from different porcine herds and compared with an indirect immunofluorescent assay (IFA). In total, 262 of 288 samples were positive as indicated by both I-ELISA and IFA. The specificity and sensitivity of I-ELISA were 87.7% and 93.57%. Conclusions This ELISA is suitable for detection and discrimination of PCV2 infection in both SPF and farm antisera. PMID:20958981

  14. Bicistronic DNA Vaccines Simultaneously Encoding HIV, HSV and HPV Antigens Promote CD8+ T Cell Responses and Protective Immunity

    PubMed Central

    Santana, Vinicius C.; Diniz, Mariana O.; Cariri, Francisco A. M. O.; Ventura, Armando M.; Cunha-Neto, Edécio; Almeida, Rafael R.; Campos, Marco A.; Lima, Graciela K.; Ferreira, Luís C. S.

    2013-01-01

    Millions of people worldwide are currently infected with human papillomavirus (HPV), herpes simplex virus (HSV) or human immunodeficiency virus (HIV). For this enormous contingent of people, the search for preventive and therapeutic immunological approaches represents a hope for the eradication of latent infection and/or virus-associated cancer. To date, attempts to develop vaccines against these viruses have been mainly based on a monovalent concept, in which one or more antigens of a virus are incorporated into a vaccine formulation. In the present report, we designed and tested an immunization strategy based on DNA vaccines that simultaneously encode antigens for HIV, HSV and HPV. With this purpose in mind, we tested two bicistronic DNA vaccines (pIRES I and pIRES II) that encode the HPV-16 oncoprotein E7 and the HIV protein p24 both genetically fused to the HSV-1 gD envelope protein. Mice i.m. immunized with the DNA vaccines mounted antigen-specific CD8+ T cell responses, including in vivo cytotoxic responses, against the three antigens. Under experimental conditions, the vaccines conferred protective immunity against challenges with a vaccinia virus expressing the HIV-derived protein Gag, an HSV-1 virus strain and implantation of tumor cells expressing the HPV-16 oncoproteins. Altogether, our results show that the concept of a trivalent HIV, HSV, and HPV vaccine capable to induce CD8+ T cell-dependent responses is feasible and may aid in the development of preventive and/or therapeutic approaches for the control of diseases associated with these viruses. PMID:23951135

  15. The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen.

    PubMed

    Chapman, Rosamund; Bourn, William R; Shephard, Enid; Stutz, Helen; Douglass, Nicola; Mgwebi, Thandi; Meyers, Ann; Chin'ombe, Nyasha; Williamson, Anna-Lise

    2014-01-01

    Numerous features make Mycobacterium bovis BCG an attractive vaccine vector for HIV. It has a good safety profile, it elicits long-lasting cellular immune responses and in addition manufacturing costs are affordable. Despite these advantages it is often difficult to express viral antigens in BCG, which results in genetic instability and low immunogenicity. The aim of this study was to generate stable recombinant BCG (rBCG) that express high levels of HIV antigens, by modification of the HIV genes. A directed evolution process was applied to recombinant mycobacteria that expressed HIV-1 Gag fused to the green fluorescent protein (GFP). Higher growth rates and increased GFP expression were selected for. Through this process a modified Gag antigen was selected. Recombinant BCG that expressed the modified Gag (BCG[pWB106] and BCG[pWB206]) were more stable, produced higher levels of antigen and grew faster than those that expressed the unmodified Gag (BCG[pWB105]). The recombinant BCG that expressed the modified HIV-1 Gag induced 2 to 3 fold higher levels of Gag-specific CD4 T cells than those expressing the unmodified Gag (BCG[pWB105]). Mice primed with 10(7) CFU BCG[pWB206] and then boosted with MVA-Gag developed Gag-specific CD8 T cells with a frequency of 1343±17 SFU/10(6) splenocytes, 16 fold greater than the response induced with MVA-Gag alone. Levels of Gag-specific CD4 T cells were approximately 5 fold higher in mice primed with BCG[pWB206] and boosted with MVA-Gag than in those receiving the MVA-Gag boost alone. In addition mice vaccinated with BCG[pWB206] were protected from a surrogate vaccinia virus challenge. PMID:25061753

  16. 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.

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

    PubMed

    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

  18. 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

  19. TH1 and TH2 responses are influenced by HLA antigens in healthy neonates vaccinated with recombinant hepatitis B vaccine.

    PubMed

    Jafarzadeh, Abdollah; Shokri, Fazel

    2012-12-01

    The immune response to hepatitis B surface antigen (HBsAg) is influenced by several factors, of which HLA antigens and balanced secretion of Th1/Th2 cytokines play important roles. The aim of this study was to evaluate the influence of HLA antigens on cytokine secretion by HBsAg-stimulated peripheral blood mononuclear cells (PBMC) from healthy neonates vaccinated with recombinant HBsAg. PBMCs were isolated from 48 Iranian neonates vaccinated with a recombinant HBV vaccine. The cells were stimulated in vitro with rHBsAg and the concentration of IL-4, IL-10, IL-12 and IFN-γ were quantitated in culture supernatant by sandwich ELISA. HLA typing was performed by microlymphocytotoxicity method. Significant diminished secretion of both Th1 (IFN-γ) and Th2 (IL-4, IL-10) cytokines was observed in HBsAg-stimulated PBMC from vaccinees expressing the HLA-DR7 compared to DR7 negative vaccinees. Similarly, lower production of these cytokines was also observed in vaccinees with DR7-DR53-DQ2, B7-DR7-DR53-DQ2 and A2-DR7-DR53-DQ2 haplotypes (p<0.05, p <0.005). While HBsAg-stimulated PBMC of DR13+ subjects produced lower levels of Th2-type cytokines (IL-4 and IL-10), those of HLA-B8+ or HLA-A9+ subjects produced higher levels of Th2-type cytokines. Cytokine secretion in response to PHA mitogen was not associated with a given HLA antigen or haplotype and was similarly represented in all groups of subjects irrespective of their HLA complex. These results indicate that HLA antigens may differentially influence cytokine secretion by HBsAg-specific T-cells of healthy neonates vaccinated with recombinant HB vaccine. This phenomenon may have an important implication for control of the immune response to HBsAg vaccine. PMID:23264407

  20. Functional Recombinant Extra Membrane Loop of Human CD20, an Alternative of the Full Length CD20 Antigen

    PubMed Central

    Anbouhi, Mahdi Habibi; Baraz, Aida Feiz; Bouzari, Saeid; Abolhassani, Mohsen; Khanahmad, Hossein; Golkar, Majid; Aghasadeghi, Mohammad Reza; Behdani, Mahdi; Najafabadi, Ali Jahanian; Shokrgozar, Mohammad Ali

    2012-01-01

    Background: Targeting of CD20 antigen with monoclonal antibodies has become the mainstay in the treatment of non-Hodgkin's lymphomas and immunotherapeutic depletion of malignant B cells. Accessibility of antigen is one of the crucial factors in development of monoclonal antibodies against this antigen. One major problem in expression of full length CD20 is aggregation and misfolding. Therefore, production of an alternative polypeptide is easer and favorable comparing to that of a full length transmembrane protein CD20. Methods: In this study, we expressed the extra membrane loop of hCD20 (exCD20) consisting of a non-glycosylated 47-amino acids region. The exCD20 coding sequence was amplified by PCR and cloned in pET32a(+) expression vector. The desired protein was expressed in fusion with thioredoxin and 6× His tag in E. coli Origami strain. ELISA and Western-blotting data were performed to indicate the functionality of this protein. Results: We have obtained the exCD20 recombinant protein which can be detected in ELISA and Western-blot experiments. This recombinant fusion protein was soluble and stable without aggregation and misfolding problems. Conclusion: The recombinant extra membrane loop of human CD20 protein in fusion with thioredoxin (exCD20) can be used in function assays and some applications such as ELISA, immuneblotting, affinity purification, immunization, screening, and development of anti-CD20 antibodies. PMID:23023212

  1. Serodiagnosis of syphilis by enzyme-linked immunosorbent assay with purified recombinant Treponema pallidum antigen 4D.

    PubMed

    Radolf, J D; Lernhardt, E B; Fehniger, T E; Lovett, M A

    1986-06-01

    An enzyme-linked immunosorbent assay (ELISA) for syphilis has been developed that detects IgG antibody to purified recombinant Treponema pallidum surface antigen 4D. The 4D ELISA was capable of detecting 25 ng of 4D antigen-specific antibody. Neither 172 nonsyphilitic sera nor 20 false-positive sera in the Venereal Disease Research Laboratory test reacted in the 4D ELISA. The sensitivity of the 4D ELISA was comparable to that of the adsorbed fluorescent treponemal antibody test in primary, secondary, and latent disease. Most sera from patients with yaws or pinta were also reactive, a result indicating that a 4D antigen-like molecule also exists in the closely related pathogenic treponemes Treponema pertenue and Treponema carateum. PMID:3517186

  2. Recombinant gp19 as a potential antigen for detecting anti-Ehrlichia canis antibodies in dog sera.

    PubMed

    Oliveira, Rômulo Silva de; Cunha, Rodrigo Casquero; Moraes-Filho, Jonas; Gonçales, Relber Aguiar; Lara, Ana Paula de Souza Stori de; Avila, Luciana Farias da Costa de; Labruna, Marcelo Bahia; Leite, Fábio Pereira Leivas

    2015-01-01

    The canine monocytic ehrlichiosis, caused by Ehrlichia canis, is endemic in several regions of Brazil. Some serological diagnostic techniques using immunodominant proteins of E. canis as antigens are available, but their specificities and sensitivities are questionable. Based on this, the objective of this study was to test the antigenic potential of the recombinant gp19 protein (rGP19) for subsequent use in diagnostic tests. The rGP19 expressed in the Escherichia coli strain BL21 (DE3) C41 was recognized in the sera from experimentally infected dogs using ELISA and Western blotting. Thus, it was possible to obtain a promising antigen with the ability to differentiate between E. canis-positive and -negative animals, even 1 week after infection. PMID:26291145

  3. Antigenicity of Recombinant Maltose Binding Protein-Mycobacterium avium subsp. paratuberculosis Fusion Proteins with and without Factor Xa Cleaving

    PubMed Central

    Begg, Douglas J.; Purdie, Auriol C.; Bannantine, John P.; Whittington, Richard J.

    2013-01-01

    Mycobacterium avium subsp. paratuberculosis causes Johne's disease (JD) in ruminants. Proteomic studies have shown that M. avium subsp. paratuberculosis expresses certain proteins when exposed to in vitro physiological stress conditions similar to the conditions experienced within a host during natural infection. Such proteins are hypothesized to be expressed in vivo, are recognized by the host immune system, and may be of potential use in the diagnosis of JD. In this study, 50 recombinant maltose binding protein (MBP)-M. avium subsp. paratuberculosis fusion proteins were evaluated using serum samples from sheep infected with M. avium subsp. paratuberculosis, and 29 (58%) were found to be antigenic. Among 50 fusion proteins, 10 were evaluated in MBP fusion and factor Xa-cleaved forms. A total of 31 proteins (62%) were found to be antigenic in either MBP fusion or factor Xa-cleaved forms. Antigenicity after cleavage and removal of the MBP tag was marginally enhanced. PMID:24132604

  4. Effects of solution conditions and surface chemistry on the adsorption of three recombinant botulinum neurotoxin antigens to aluminum salt adjuvants.

    PubMed

    Vessely, Christina; Estey, Tia; Randolph, Theodore W; Henderson, Ian; Nayar, Rajiv; Carpenter, John F

    2007-09-01

    Botulinum neurotoxin (BoNT) is a biological warfare threat. Protein antigens have been developed against the seven major BoNT serotypes for the development of a recombinant protein vaccine. This study is an evaluation of adsorption profiles for three of the recombinant protein antigens to aluminum salt adjuvants in the development of a trivalent vaccine against BoNT. Adsorption profiles were obtained over a range of protein concentrations. The results document that charge-charge interactions dominate the adsorption of antigen to adjuvant. Optimal conditions for adsorption were determined. However, potency studies and solution stability studies indicated the necessity of using aluminum hydroxide adjuvant at low pH. To improve the adsorption profiles to AlOH adjuvant, phosphate ions were introduced into the adsorption buffers. The resulting change in the adjuvant chemistry led to an improvement of adsorption of the BoNT antigens to aluminum hydroxide adjuvant while maintaining potency. Competitive adsorption profiles were also determined, and showed changes in maximum adsorption from mixed solutions compared to adsorption from individual protein solutions. The adsorption profiles for each protein varied due to differences in adsorption mechanism and affinity for the adjuvant surface. These results emphasize the importance of evaluating competitive adsorption in the development of multivalent vaccine products. PMID:17518359

  5. Adjuvant activity of chicken interleukin-12 co-administered with infectious bursal disease virus recombinant VP2 antigen in chickens.

    PubMed

    Su, Bor Sheu; Chiu, Hua Hsien; Lin, Cheng Chung; Shien, Jui Hung; Yin, Hsien Sheng; Lee, Long Huw

    2011-02-15

    A recombinant fowlpox virus (rFPV/VP2) expressing infectious bursal diseases virus (IBDV) VP2 gene has been constructed. After purification and identification of rFPV/VP2, the adjuvant activity of the recombinant chicken IL-12 (rchIL-12), synthesized by our previous construct of rFPV/chIL-12, in rFPV/VP2-expressed rVP2 antigen was assessed in one-week-old specific-pathogen free chickens. The results indicated that rchIL-12 alone or rchIL-12 plus mineral oil (MO) co-administered with rVP2 antigen significantly enhanced the production of serum neutralization (SN) antibody against IBDV, compared to those with MO alone. The SN titers in groups receiving rVP2 antigen with MO alone were more inconsistent after vaccination. On the other hand, rchIL-12 significantly stimulated IFN-γ production in serum and in splenocyte cultured supernatant, suggesting that rchIL-12 alone or plus MO significantly induced a cell-mediated immune response. Finally, bursal lesion protection from very virulent IBDV (vvIBDV) challenge in chickens receiving rVP2 antigen with rchIL-12 alone or plus MO was much more effective than that with MO alone at two weeks after boosting. Taken together, rchIL-12 alone augmented in vivo the induction of a primary and also a secondary SN antibody production and a cell-mediated immunity against IBDV rVP2 antigen, which conferred the enhancement of bursal lesion protective efficacy from vvIBDV challenge. These data indicated that a potential for chIL-12 as immunoadjuvant for chicken vaccine development such as IBDV rVP2 antigen. PMID:21035196

  6. Development of Ss-NIE-1 Recombinant Antigen Based Assays for Immunodiagnosis of Strongyloidiasis

    PubMed Central

    Rascoe, Lisa N.; Price, Courtney; Shin, Sun Hee; McAuliffe, Isabel; Priest, Jeffrey W.; Handali, Sukwan

    2015-01-01

    Strongyloides stercoralis is a widely distributed parasite that infects 30 to 100 million people worldwide. In the United States strongyloidiasis is recognized as an important infection in immigrants and refugees. Public health and commercial reference laboratories need a simple and reliable method for diagnosis of strongyloidiasis to identify and treat cases and to prevent transmission. The recognized laboratory test of choice for diagnosis of strongyloidiasis is detection of disease specific antibodies, most commonly using a crude parasite extract for detection of IgG antibodies. Recently, a luciferase tagged recombinant protein of S. stercoralis, Ss-NIE-1, has been used in a luciferase immunoprecipitation system (LIPS) to detect IgG and IgG4 specific antibodies. To promote wider adoption of immunoassays for strongyloidiasis, we used the Ss-NIE-1 recombinant antigen without the luciferase tag and developed ELISA and fluorescent bead (Luminex) assays to detect S. stercoralis specific IgG4. We evaluated the assays using well-characterized sera from persons with or without presumed strongyloidiasis. The sensitivity and specificity of Ss-NIE-1 IgG4 ELISA were 95% and 93%, respectively. For the IgG4 Luminex assay, the sensitivity and specificity were 93% and 95%, respectively. Specific IgG4 antibody decreased after treatment in a manner that was similar to the decrease of specific IgG measured in the crude IgG ELISA. The sensitivities of the Ss-NIE-1 IgG4 ELISA and Luminex assays were comparable to the crude IgG ELISA but with improved specificities. However, the Ss-NIE-1 based assays are not dependent on native parasite materials and can be performed using widely available laboratory equipment. In conclusion, these newly developed Ss-NIE-1 based immunoassays can be readily adopted by public health and commercial reference laboratories for routine screening and clinical diagnosis of S. stercoralis infection in refugees and immigrants in the United States. PMID

  7. Development of Ss-NIE-1 recombinant antigen based assays for immunodiagnosis of strongyloidiasis.

    PubMed

    Rascoe, Lisa N; Price, Courtney; Shin, Sun Hee; McAuliffe, Isabel; Priest, Jeffrey W; Handali, Sukwan

    2015-04-01

    Strongyloides stercoralis is a widely distributed parasite that infects 30 to 100 million people worldwide. In the United States strongyloidiasis is recognized as an important infection in immigrants and refugees. Public health and commercial reference laboratories need a simple and reliable method for diagnosis of strongyloidiasis to identify and treat cases and to prevent transmission. The recognized laboratory test of choice for diagnosis of strongyloidiasis is detection of disease specific antibodies, most commonly using a crude parasite extract for detection of IgG antibodies. Recently, a luciferase tagged recombinant protein of S. stercoralis, Ss-NIE-1, has been used in a luciferase immunoprecipitation system (LIPS) to detect IgG and IgG4 specific antibodies. To promote wider adoption of immunoassays for strongyloidiasis, we used the Ss-NIE-1 recombinant antigen without the luciferase tag and developed ELISA and fluorescent bead (Luminex) assays to detect S. stercoralis specific IgG4. We evaluated the assays using well-characterized sera from persons with or without presumed strongyloidiasis. The sensitivity and specificity of Ss-NIE-1 IgG4 ELISA were 95% and 93%, respectively. For the IgG4 Luminex assay, the sensitivity and specificity were 93% and 95%, respectively. Specific IgG4 antibody decreased after treatment in a manner that was similar to the decrease of specific IgG measured in the crude IgG ELISA. The sensitivities of the Ss-NIE-1 IgG4 ELISA and Luminex assays were comparable to the crude IgG ELISA but with improved specificities. However, the Ss-NIE-1 based assays are not dependent on native parasite materials and can be performed using widely available laboratory equipment. In conclusion, these newly developed Ss-NIE-1 based immunoassays can be readily adopted by public health and commercial reference laboratories for routine screening and clinical diagnosis of S. stercoralis infection in refugees and immigrants in the United States. PMID

  8. Prevention and Immunotherapy of Secondary Murine Alveolar Echinococcosis Employing Recombinant EmP29 Antigen

    PubMed Central

    Boubaker, Ghalia; Hemphill, Andrew; Huber, Cristina Olivia; Spiliotis, Markus; Babba, Hamouda; Gottstein, Bruno

    2015-01-01

    Alveolar echinococcosis (AE) is caused by infection with the larval stage of the tapeworm Echinococcus multilocularis. An increasing understanding of immunological events that account for the metacestode survival in human and murine AE infection prompted us to undertake explorative experiments tackling the potential of novel preventive and/or immunotherapeutic measures. In this study, the immunoprotective and immunotherapeutic ability of recombinant EmP29 antigen (rEmP29) was assessed in mice that were intraperitoneally infected with E. multilocularis metacestodes. For vaccination, three intraperitoneal injections with 20μg rEmP29 emulsified in saponin adjuvants were applied over 6 weeks. 2 weeks after the last boost, mice were infected, and at 90 days post-infection, rEmP29-vaccinated mice exhibited a median parasite weight that was reduced by 75% and 59% when compared to NaCl- or saponin–treated control mice, respectively. For immunotherapeutical application, the rEmP29 (20μg) vaccine was administered to experimentally infected mice, starting at 1 month post-infection, three times with 2 weeks intervals. Mice undergoing rEmP29 immunotherapy exhibited a median parasite load that was reduced by 53% and 49% when compared to NaCl- and saponin–treated control mice, respectively. Upon analysis of spleen cells, both, vaccination and treatment with rEmP29, resulted in low ratios of Th2/Th1 (IL-4/IFN-γ) cytokine mRNA and low levels of mRNA coding for IL-10 and IL-2. These results suggest that reduction of the immunosuppressive environment takes place in vaccinated as well as immunotreated mice, and a shift towards a Th1 type of immune response may be responsible for the observed increased restriction of parasite growth. The present study provides the first evidence that active immunotherapy may present a sustainable route for the control of AE. PMID:26053794

  9. Effect of homologous and heterologous prime-boost on the immune response to recombinant plague antigens.

    PubMed

    Glynn, Audrey; Freytag, Lucy C; Clements, John D

    2005-03-14

    Among the pathogens that have been identified as potential agents of biological warfare or bioterrorism, Yersinia pestis is one of the main concerns due to the severity and potential transmissibility of the pneumonic form of the disease in humans. There are no approved vaccines for protection against pneumonic plague, but a Y. pestis-derived fusion protein (F1-V) has shown great promise as a protective antigen in murine studies. In the current study, we examine different prime-boost regimens, including parenteral, mucosal, and transcutaneous delivery, in order to explore the effect of changing the route of prime and boost on the ability of recombinant F1-V to promote the development of long-lasting, high-titer antibodies. The most significant findings of the study reported here are that (1) intranasal and subcutaneous immunizations are both effective and essentially equivalent for induction of serum and bronchioalveolar anti-F1-V IgG1 responses when a single booster dose is administered by the same (homologous) route, (2) heterologous boosting can be as or more effective than homologous boosting for induction of either serum or bronchioalveolar anti-F1-V IgG1 responses, and (3) anti-F1 and anti-V total IgG responses were highest in animals primed intranasally and boosted by any route when compared to animals primed transcutaneously or subcutaneously. As with previously published studies, there were still significant levels of circulating anti-F1-V antibodies 1 year post-primary immunization. These studies provide important insights into the development of new-generation biodefense vaccines. PMID:15734068

  10. Screening of recombinant proteins as antigens in indirect ELISA for diagnosis of bovine tuberculosis.

    PubMed

    Souza, Ingrid If; Melo, Elaine Sp; Ramos, Carlos An; Farias, Thaís A; Osório, Ana Luiza Ar; Jorge, Klaudia Sg; Vidal, Carlos Es; Silva, Altino S; Silva, Márcio R; Pellegrin, Aiesca O; Araújo, Flábio R

    2012-12-01

    Bovine tuberculosis is an important infectious disease caused by Mycobacterium bovis, which is responsible for considerable economic losses. This disease constitutes a serious public health problem. Control programs in most countries, including Brazil, are based on the identification and slaughter of infected animals, as defined by the skin tuberculin test, which has its constraints. In the present study, the recombinant proteins CFP-10, ESAT-6, Mb0143, MPB83, PE5, PE13, TB10.4, TB15.3 and a chimera of ESAT-6/MPB70/MPB83 (fusion protein) were tested as ELISA antigens for the diagnosis of bovine tuberculosis. The proteins were produced in Escherichia coli, purified and tested in ELISAs with sera from 126 cattle having tested negative in the comparative intradermal tuberculin test (CITT) and 107 sera from cattle having tested positive in the CITT. Also, 236 sera from two BTB-free beef cattle herds were tested. Among the proteins tested, only the ESAT-6/MPB70/MPB83 chimera demonstrated satisfactory agreement with the CITT (kappa index: 0.688), reflecting in 83.2% sensitivity and 86.5% specificity. The ELISA absorbances of the cattle sera from BTB-free herds showed similar levels to those of CITT positive cattle, probably as the result of successive skin tuberculinizations to define the BTB-free status of the herds. However, the ELISA with the ESAT-6/MPB70/MPB83 chimera was useful to discriminate BTB positive and negative cattle in herds prior to the tuberculin skin test. PMID:23419946

  11. Potential of recombinant inorganic pyrophosphatase antigen as a new vaccine candidate against Baylisascaris schroederi in mice.

    PubMed

    Xie, Yue; Chen, Sijie; Yan, Yubo; Zhang, Zhihe; Li, Desheng; Yu, Hua; Wang, Chengdong; Nong, Xiang; Zhou, Xuan; Gu, Xiaobin; Wang, Shuxian; Peng, Xuerong; Yang, Guangyou

    2013-01-01

    The intestinal nematode Baylisascaris schroederi is an important cause of death for wild and captive giant pandas. Inorganic pyrophosphatases (PPases) are critical for development and molting in nematode parasites and represent potential targets for vaccination. Here, a new PPase homologue, Bsc-PYP-1, from B. schroederi was identified and characterized, and its potential as a vaccine candidate was evaluated in a mouse challenge model. Sequence alignment of PPases from nematode parasites and other organisms show that Bsc-PYP-1 is a nematode-specific member of the family I soluble PPases. Immunohistochemistry revealed strong localization of native Bsc-PYP-1 to the body wall, gut epithelium, ovary and uterus of adult female worms. Additionally, Bsc-PYP-1 homologues were found in roundworms infecting humans (Ascaris lumbricoides), swine (Ascaris suum) and dogs (Toxocara canis). In two vaccine trials, recombinant Bsc-PYP-1 (rBsc-PYP-1) formulated with Freund complete adjuvant induced significantly high antigen-specific immunoglobulin (Ig)G but no IgE or IgM responses. Analysis of IgG-subclass profiles revealed a greater increase of IgG1 than IgG2a. Splenocytes from rBsc-PYP-1/FCA-immunized mice secreted low levels of T helper (Th)1-type cytokines, interferon-γ and interleukin (IL)-2, while producing significantly high levels of IL-10 and significantly elevated levels of IL-4 (Th2 cytokines) after stimulation with rBsc-PYP-1 in vitro. Finally, vaccinated mice had 69.02-71.15% reductions (in 2 experiments) in larval recovery 7 days post-challenge (dpc) and 80% survival at 80 dpc. These results suggest that Th2-mediated immunity elicited by rBsc-PYP-1 provides protection against B. schroederi, and the findings should contribute to further development of Bsc-PYP-1 as a candidate vaccine against baylisascariasis. PMID:24090087

  12. Recombinative events of the T cell antigen receptor delta gene in peripheral T cell lymphomas.

    PubMed Central

    Kanavaros, P; Farcet, J P; Gaulard, P; Haioun, C; Divine, M; Le Couedic, J P; Lefranc, M P; Reyes, F

    1991-01-01

    Recombinative events of the T cell antigen receptor (TCR) delta-chain gene were studied in 37 cases of peripheral T cell lymphoma (PTCL) and related to their clinical presentation and the expression of the alpha beta or gamma delta heterodimers as determined by immunostaining of frozen tissue samples. There were 22 cases of alpha beta, 5 cases of gamma delta, and 10 cases of silent TCR expressing neither the alpha beta nor gamma delta TCR. 5 different probes were used to examine the delta locus. The 22 cases of alpha beta PTCL displayed biallelic and monoallelic deletions; a monoallelic V delta 1 J delta 1 rearrangement was observed in 1 case and a monoallelic germ line configuration in 7 cases. The 5 cases of gamma delta PTCL displayed biallelic rearrangements: the productive rearrangements could be ascribed to V delta 1J delta 1 joining in 3 cases and VJ delta 1 joining in 2 cases according to the combined pattern of DNA hybridization with the appropriate probes and of cell reactivity with the TCR delta-1, delta TCS-1, and anti-V delta 2 monoclonal antibodies. In the VJ delta 1 joining, the rearranged V segments were located between V delta 1 and V delta 2. Interestingly, in the third group of 10 cases of silent PTCL, 5 cases were found to have a TCR gene configuration identical to that in the TCR alpha beta PTCL, as demonstrated by biallelic delta gene deletion. These 5 cases were CD3 positive. The 5 remaining cases showed a monoallelic delta gene rearrangement with a monoallelic germ line configuration in 4 and a monoallelic deletion in 1. Four of these cases were CD3 negative, which was consistent with an immature genotype the TCR commitent of which could not be ascertained. Finally, TCR gamma delta PTCL consisted of a distinct clinical morphological and molecular entity whereas TCR alpha beta and silent PTCL had a similar presentation. Images PMID:1991851

  13. Temperature-mediated recombinant anthrax protective antigen aggregate development: Implications for toxin formation and immunogenicity.

    PubMed

    Amador-Molina, Juan C; Valerdi-Madrigal, Esther D; Domínguez-Castillo, Rocío I; Sirota, Lev A; Arciniega, Juan L

    2016-07-29

    Anthrax vaccines containing recombinant PA (rPA) as the only antigen face a stability issue: rPA forms aggregates in solution after exposure to temperatures ⩾40°C, thus losing its ability to form lethal toxin (LeTx) with Lethal Factor. To study rPA aggregation's impact on immune response, we subjected rPA to several time and temperature combinations. rPA treated at 50°C for 30min formed high mass aggregates when analyzed by gel electrophoresis and failed to form LeTx as measured by a macrophage lysis assay (MLA). Aggregated rPA-formed LeTx was about 30 times less active than LeTx containing native rPA. Mice immunized with heat-treated rPA combined with Al(OH)3 developed antibody titers about 49 times lower than mice immunized with native rPA, as measured by a Toxicity Neutralization Assay (TNA). Enzyme Linked Immunosorbent Assay (ELISA) of the same immune sera showed anti-rPA titers only 2-7 times lower than titers elicited by native rPA. Thus, rPA's ability to form LeTx correlates with its production of neutralizing antibodies, and aggregation significantly impairs the protein's antibody response. However, while these findings suggest MLA has some value as an in-process quality test for rPA in new anthrax vaccines, they also confirm the superiority of TNA for use in vaccine potency. PMID:27364097

  14. Evaluation of Recombinant Antigen-Based Assays for Diagnosis of Bullous Autoimmune Diseases

    PubMed Central

    D'Agosto, G.; Latini, A.; Carducci, M.; Mastroianni, A.; Vento, A.; Fei, P. Cordiali

    2004-01-01

    The diagnosis of autoimmune bullous diseases is based on clinical observation and on the presence of autoantibodies directed to molecules involved in the adhesion systems of the skin. Immunofluorescence assays are the currently accepted method for detection of autoantibodies; such assays depend greatly on the skill of operators and are difficult to standardize. Recombinant desmoglein-1 (Dsg1), Dsg3, and BP180 peptides, the main autoantigens in pemphigus or bullous pemphigoid, have been used to develop new quantitative enzyme immunoassays (EIA) for the detection of specific antibodies. The present study was undertaken to evaluate the sensitivity and specificity of these immunoassays and to determine the correlation between the results and the clinical aspects of diseases. Serum samples from patients with pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, or mucous membrane pemphigoid, from healthy individuals, and from patients with unrelated autoimmune conditions were tested. Anti-desmoglein reactivity was detected in all the patients with pemphigus and in none of the controls. Patients with the more benign form of cutaneous disease had anti-Dsg1 antibodies, while patients with deeper cutaneous lesions or with mucosal involvement had anti-Dsg3 reactivity also, or exclusively. The BP180-based assay was positive for 66.6% of patients with bullous pemphigoid and for none of the patients with mucous membrane pemphigoid, and no reactivity was detected in the control sera. In conclusion, the anti-Dsg1 and anti-Dsg3 assays are useful in the diagnosis of pemphigus and provide information on the clinical phenotype of the disease. However, the sensitivity of EIA for detection of autoantibodies in bullous pemphigoid should be improved by the use of additional antigens or epitopes. PMID:15242953

  15. Potential of recombinant inorganic pyrophosphatase antigen as a new vaccine candidate against Baylisascaris schroederi in mice

    PubMed Central

    2013-01-01

    The intestinal nematode Baylisascaris schroederi is an important cause of death for wild and captive giant pandas. Inorganic pyrophosphatases (PPases) are critical for development and molting in nematode parasites and represent potential targets for vaccination. Here, a new PPase homologue, Bsc-PYP-1, from B. schroederi was identified and characterized, and its potential as a vaccine candidate was evaluated in a mouse challenge model. Sequence alignment of PPases from nematode parasites and other organisms show that Bsc-PYP-1 is a nematode-specific member of the family I soluble PPases. Immunohistochemistry revealed strong localization of native Bsc-PYP-1 to the body wall, gut epithelium, ovary and uterus of adult female worms. Additionally, Bsc-PYP-1 homologues were found in roundworms infecting humans (Ascaris lumbricoides), swine (Ascaris suum) and dogs (Toxocara canis). In two vaccine trials, recombinant Bsc-PYP-1 (rBsc-PYP-1) formulated with Freund complete adjuvant induced significantly high antigen-specific immunoglobulin (Ig)G but no IgE or IgM responses. Analysis of IgG-subclass profiles revealed a greater increase of IgG1 than IgG2a. Splenocytes from rBsc-PYP-1/FCA-immunized mice secreted low levels of T helper (Th)1-type cytokines, interferon-γ and interleukin (IL)-2, while producing significantly high levels of IL-10 and significantly elevated levels of IL-4 (Th2 cytokines) after stimulation with rBsc-PYP-1 in vitro. Finally, vaccinated mice had 69.02–71.15% reductions (in 2 experiments) in larval recovery 7 days post-challenge (dpc) and 80% survival at 80 dpc. These results suggest that Th2-mediated immunity elicited by rBsc-PYP-1 provides protection against B. schroederi, and the findings should contribute to further development of Bsc-PYP-1 as a candidate vaccine against baylisascariasis. PMID:24090087

  16. Genetic diversity and population structure of genes encoding vaccine candidate antigens of Plasmodium vivax

    PubMed Central

    2012-01-01

    Background A major concern in malaria vaccine development is genetic polymorphisms typically observed among Plasmodium isolates in different geographical areas across the world. Highly polymorphic regions have been observed in Plasmodium falciparum and Plasmodium vivax antigenic surface proteins such as Circumsporozoite protein (CSP), Duffy-binding protein (DBP), Merozoite surface protein-1 (MSP-1), Apical membrane antigen-1 (AMA-1) and Thrombospondin related anonymous protein (TRAP). Methods Genetic variability was assessed in important polymorphic regions of various vaccine candidate antigens in P. vivax among 106 isolates from the Amazon Region of Loreto, Peru. In addition, genetic diversity determined in Peruvian isolates was compared to population studies from various geographical locations worldwide. Results The structured diversity found in P. vivax populations did not show a geographic pattern and haplotypes from all gene candidates were distributed worldwide. In addition, evidence of balancing selection was found in polymorphic regions of the trap, dbp and ama-1 genes. Conclusions It is important to have a good representation of the haplotypes circulating worldwide when implementing a vaccine, regardless of the geographic region of deployment since selective pressure plays an important role in structuring antigen diversity. PMID:22417572

  17. Immunization with recombinantly expressed glycan antigens from Schistosoma mansoni induces glycan-specific antibodies against the parasite

    PubMed Central

    Prasanphanich, Nina Salinger; Luyai, Anthony E; Song, Xuezheng; Heimburg-Molinaro, Jamie; Mandalasi, Msano; Mickum, Megan; Smith, David F; Nyame, A Kwame; Cummings, Richard D

    2014-01-01

    Schistosomiasis caused by infection with parasitic helminths of Schistosoma spp. is a major global health problem due to inadequate treatment and lack of a vaccine. The immune response to schistosomes includes glycan antigens, which could be valuable diagnostic markers and vaccine targets. However, no precedent exists for how to design vaccines targeting eukaryotic glycoconjugates. The di- and tri-saccharide motifs LacdiNAc (GalNAcβ1,4GlcNAc; LDN) and fucosylated LacdiNAc (GalNAcβ1,4(Fucα1-3)GlcNAc; LDNF) are the basis for several important schistosome glycan antigens. They occur in monomeric form or as repeating units (poly-LDNF) and as part of a variety of different glycoconjugates. Because chemical synthesis and conjugation of such antigens is exceedingly difficult, we sought to develop a recombinant expression system for parasite glycans. We hypothesized that presentation of parasite glycans on the cell surface would induce glycan-specific antibodies. We generated Chinese hamster ovary (CHO) Lec8 cell lines expressing poly-LDN (L8-GT) and poly-LDNF (L8-GTFT) abundantly on their membrane glycoproteins. Sera from Schistosoma mansoni-infected mice were highly cross-reactive with the cells and with cell-surface N-glycans. Immunizing mice with L8-GT and L8-GTFT cells induced glycan-specific antibodies. The L8-GTFT cells induced a sustained booster response, with antibodies that bound to S. mansoni lysates and recapitulated the exquisite specificity of the anti-parasite response for particular presentations of LDNF antigen. In summary, this recombinant expression system promotes successful generation of antibodies to the glycans of S. mansoni, and it can be adapted to study the role of glycan antigens and anti-glycan immune responses in many other infections and pathologies. PMID:24727440

  18. Immunogenicity and protective efficacy of recombinant Modified Vaccinia virus Ankara candidate vaccines delivering West Nile virus envelope antigens.

    PubMed

    Volz, Asisa; Lim, Stephanie; Kaserer, Martina; Lülf, Anna; Marr, Lisa; Jany, Sylvia; Deeg, Cornelia A; Pijlman, Gorben P; Koraka, Penelope; Osterhaus, Albert D M E; Martina, Byron E; Sutter, Gerd

    2016-04-01

    West Nile virus (WNV) cycles between insects and wild birds, and is transmitted via mosquito vectors to horses and humans, potentially causing severe neuroinvasive disease. Modified Vaccinia virus Ankara (MVA) is an advanced viral vector for developing new recombinant vaccines against infectious diseases and cancer. Here, we generated and evaluated recombinant MVA candidate vaccines that deliver WNV envelope (E) antigens and fulfil all the requirements to proceed to clinical testing in humans. Infections of human and equine cell cultures with recombinant MVA demonstrated efficient synthesis and secretion of WNV envelope proteins in mammalian cells non-permissive for MVA replication. Prime-boost immunizations in BALB/c mice readily induced circulating serum antibodies binding to recombinant WNV E protein and neutralizing WNV in tissue culture infections. Vaccinations in HLA-A2.1-/HLA-DR1-transgenic H-2 class I-/class II-knockout mice elicited WNV E-specific CD8+ T cell responses. Moreover, the MVA-WNV candidate vaccines protected C57BL/6 mice against lineage 1 and lineage 2 WNV infection and induced heterologous neutralizing antibodies. Thus, further studies are warranted to evaluate these recombinant MVA-WNV vaccines in other preclinical models and use them as candidate vaccine in humans. PMID:26939903

  19. Vaccination with Replication Deficient Adenovectors Encoding YF-17D Antigens Induces Long-Lasting Protection from Severe Yellow Fever Virus Infection in Mice.

    PubMed

    Bassi, Maria R; Larsen, Mads A B; Kongsgaard, Michael; Rasmussen, Michael; Buus, Søren; Stryhn, Anette; Thomsen, Allan R; Christensen, Jan P

    2016-02-01

    The live attenuated yellow fever vaccine (YF-17D) has been successfully used for more than 70 years. It is generally considered a safe vaccine, however, recent reports of serious adverse events following vaccination have raised concerns and led to suggestions that even safer YF vaccines should be developed. Replication deficient adenoviruses (Ad) have been widely evaluated as recombinant vectors, particularly in the context of prophylactic vaccination against viral infections in which induction of CD8+ T-cell mediated immunity is crucial, but potent antibody responses may also be elicited using these vectors. In this study, we present two adenobased vectors targeting non-structural and structural YF antigens and characterize their immunological properties. We report that a single immunization with an Ad-vector encoding the non-structural protein 3 from YF-17D could elicit a strong CD8+ T-cell response, which afforded a high degree of protection from subsequent intracranial challenge of vaccinated mice. However, full protection was only observed using a vector encoding the structural proteins from YF-17D. This vector elicited virus-specific CD8+ T cells as well as neutralizing antibodies, and both components were shown to be important for protection thus mimicking the situation recently uncovered in YF-17D vaccinated mice. Considering that Ad-vectors are very safe, easy to produce and highly immunogenic in humans, our data indicate that a replication deficient adenovector-based YF vaccine may represent a safe and efficient alternative to the classical live attenuated YF vaccine and should be further tested. PMID:26886513

  20. Vaccination with Replication Deficient Adenovectors Encoding YF-17D Antigens Induces Long-Lasting Protection from Severe Yellow Fever Virus Infection in Mice

    PubMed Central

    Bassi, Maria R.; Larsen, Mads A. B.; Kongsgaard, Michael; Rasmussen, Michael; Buus, Søren; Stryhn, Anette; Thomsen, Allan R.; Christensen, Jan P.

    2016-01-01

    The live attenuated yellow fever vaccine (YF-17D) has been successfully used for more than 70 years. It is generally considered a safe vaccine, however, recent reports of serious adverse events following vaccination have raised concerns and led to suggestions that even safer YF vaccines should be developed. Replication deficient adenoviruses (Ad) have been widely evaluated as recombinant vectors, particularly in the context of prophylactic vaccination against viral infections in which induction of CD8+ T-cell mediated immunity is crucial, but potent antibody responses may also be elicited using these vectors. In this study, we present two adenobased vectors targeting non-structural and structural YF antigens and characterize their immunological properties. We report that a single immunization with an Ad-vector encoding the non-structural protein 3 from YF-17D could elicit a strong CD8+ T-cell response, which afforded a high degree of protection from subsequent intracranial challenge of vaccinated mice. However, full protection was only observed using a vector encoding the structural proteins from YF-17D. This vector elicited virus-specific CD8+ T cells as well as neutralizing antibodies, and both components were shown to be important for protection thus mimicking the situation recently uncovered in YF-17D vaccinated mice. Considering that Ad-vectors are very safe, easy to produce and highly immunogenic in humans, our data indicate that a replication deficient adenovector-based YF vaccine may represent a safe and efficient alternative to the classical live attenuated YF vaccine and should be further tested. PMID:26886513

  1. Expression and refolding of the protective antigen of Bacillus anthracis: A model for high-throughput screening of antigenic recombinant protein refolding.

    PubMed

    Pavan, María Elisa; Pavan, Esteban Enrique; Cairó, Fabián Martín; Pettinari, María Julia

    2016-01-01

    Bacillus anthracis protective antigen (PA) is a well known and relevant immunogenic protein that is the basis for both anthrax vaccines and diagnostic methods. Properly folded antigenic PA is necessary for these applications. In this study a high level of PA was obtained in recombinant Escherichia coli. The protein was initially accumulated in inclusion bodies, which facilitated its efficient purification by simple washing steps; however, it could not be recognized by specific antibodies. Refolding conditions were subsequently analyzed in a high-throughput manner that enabled nearly a hundred different conditions to be tested simultaneously. The recovery of the ability of PA to be recognized by antibodies was screened by dot blot using a coefficient that provided a measure of properly refolded protein levels with a high degree of discrimination. The best refolding conditions resulted in a tenfold increase in the intensity of the dot blot compared to the control. The only refolding additive that consistently yielded good results was L-arginine. The statistical analysis identified both cooperative and negative interactions between the different refolding additives. The high-throughput approach described in this study that enabled overproduction, purification and refolding of PA in a simple and straightforward manner, can be potentially useful for the rapid screening of adequate refolding conditions for other overexpressed antigenic proteins. PMID:26777581

  2. Novel recombinant BCG expressing perfringolysin O and the over-expression of key immunodominant antigens; pre-clinical characterization, safety and protection against challenge with Mycobacterium tuberculosis.

    PubMed

    Sun, Ronggai; Skeiky, Yasir A W; Izzo, Angelo; Dheenadhayalan, Veerabadran; Imam, Zakaria; Penn, Erica; Stagliano, Katherine; Haddock, Scott; Mueller, Stefanie; Fulkerson, John; Scanga, Charles; Grover, Ajay; Derrick, Steven C; Morris, Sheldon; Hone, David M; Horwitz, Marcus A; Kaufmann, Stefan H E; Sadoff, Jerald C

    2009-07-16

    Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), has infected approximately two billion individuals worldwide with approximately 9.2 million new cases and 1.6 million deaths annually. Current efforts are focused on making better BCG priming vaccines designed to induce a comprehensive and balanced immunity followed by booster(s) targeting a specific set of relevant antigens in common with the BCG prime. We describe the generation and immunological characterization of recombinant BCG strains with properties associated with lysis of the endosome compartment and over-expression of key Mtb antigens. The endosome lysis strain, a derivative of BCG SSI-1331 (BCG(1331)) expresses a mutant form of perfringolysin O (PfoA(G137Q)), a cytolysin normally secreted by Clostridium perfringens. Integration of the PfoA(G137Q) gene into the BCG genome was accomplished using an allelic exchange plasmid to replace ureC with pfoA(G137Q) under the control of the Ag85B promoter. The resultant BCG construct, designated AERAS-401 (BCG(1331) DeltaureC::OmegapfoA(G137Q)) secreted biologically active Pfo, was well tolerated with a good safety profile in immunocompromised SCID mice. A second rBCG strain, designated AFRO-1, was generated by incorporating an expression plasmid encoding three mycobacterial antigens, Ag85A, Ag85B and TB10.4, into AERAS-401. Compared to the parental BCG strain, vaccination of mice and guinea pigs with AFRO-1 resulted in enhanced immune responses. Mice vaccinated with AFRO-1 and challenged with the hypervirulent Mtb strain HN878 also survived longer than mice vaccinated with the parental BCG. Thus, we have generated improved rBCG vaccine candidates that address many of the shortcomings of the currently licensed BCG vaccine strains. PMID:19500523

  3. Comparison of the structural stability and dynamic properties of recombinant anthrax protective antigen and its 2-fluorohistidine-labeled analogue.

    PubMed

    Hu, Lei; Joshi, Sangeeta B; Andra, Kiran K; Thakkar, Santosh V; Volkin, David B; Bann, James G; Middaugh, C Russell

    2012-11-01

    Protective antigen (PA) is the primary protein antigenic component of both the currently used anthrax vaccine and related recombinant vaccines under development. An analogue of recombinant PA (2-FHis rPA) has been recently shown to block the key steps of pore formation in the process of inducing cytotoxicity in cells, and thus can potentially be used as an antitoxin or a vaccine. This rPA analogue was produced by fermentation to incorporate the unnatural amino acid 2-fluorohistidine (2-FHis). In this study, the effects of 2-FHis labeling on rPA antigen's conformational stability and dynamic properties were investigated by various biophysical techniques. Temperature/pH stability profiles of rPA and 2-FHis rPA were analyzed by the empirical phase diagram (EPD) approach, and physical stability differences between them were identified. Results showed that rPA and 2-FHis rPA had similar stability at pH 7-8. With decreasing solution pH, however, 2-FHis rPA was found to be more stable. Dynamic sensitive measurements of the two proteins at pH 5 found that 2-FHis rPA was more dynamic and/or differentially hydrated under acidic pH conditions. The biophysical characterization and stability data provide information useful for the potential development of 2-FHis rPA as a more stable rPA vaccine candidate. PMID:22911632

  4. Low-Dose Adenovirus Vaccine Encoding Chimeric Hepatitis B Virus Surface Antigen-Human Papillomavirus Type 16 E7 Proteins Induces Enhanced E7-Specific Antibody and Cytotoxic T-Cell Responses

    PubMed Central

    Báez-Astúa, Andrés; Herráez-Hernández, Elsa; Garbi, Natalio; Pasolli, Hilda A.; Juárez, Victoria; zur Hausen, Harald; Cid-Arregui, Angel

    2005-01-01

    Induction of effective immune responses may help prevent cancer progression. Tumor-specific antigens, such as those of human papillomaviruses involved in cervical cancer, are targets with limited intrinsic immunogenicity. Here we show that immunization with low doses (106 infectious units/dose) of a recombinant human adenovirus type 5 encoding a fusion of the E7 oncoprotein of human papillomavirus type 16 to the carboxyl terminus of the surface antigen of hepatitis B virus (HBsAg) induces remarkable E7-specific humoral and cellular immune responses. The HBsAg/E7 fusion protein assembled efficiently into virus-like particles, which stimulated antibody responses against both carrier and foreign antigens, and evoked antigen-specific kill of an indicator cell population in vivo. Antibody and T-cell responses were significantly higher than those induced by a control adenovirus vector expressing wild-type E7. Such responses were not affected by preexisting immunity against either HBsAg or adenovirus. These data demonstrate that the presence of E7 on HBsAg particles does not interfere with particle secretion, as it occurs with bigger proteins fused to the C terminus of HBsAg, and results in enhancement of CD8+-mediated T-cell responses to E7. Thus, fusion to HBsAg is a convenient strategy for developing cervical cancer therapeutic vaccines, since it enhances the immunogenicity of E7 while turning it into an innocuous secreted fusion protein. PMID:16188983

  5. Recombinant Antigen-Based Enzyme-Linked Immunosorbent Assay for Diagnosis of Baylisascaris procyonis Larva Migrans ▿

    PubMed Central

    Dangoudoubiyam, Sriveny; Vemulapalli, Ramesh; Ndao, Momar; Kazacos, Kevin R.

    2011-01-01

    Baylisascaris larva migrans is an important zoonotic disease caused by Baylisascaris procyonis, the raccoon roundworm, and is being increasingly considered in the differential diagnosis of eosinophilic meningoencephalitis in children and young adults. Although a B. procyonis excretory-secretory (BPES) antigen-based enzyme-linked immunosorbent assay (ELISA) and a Western blot assay are useful in the immunodiagnosis of this infection, cross-reactivity remains a major problem. Recently, a recombinant B. procyonis antigen, BpRAG1, was reported for use in the development of improved serological assays for the diagnosis of Baylisascaris larva migrans. In this study, we tested a total of 384 human patient serum samples in a BpRAG1 ELISA, including samples from 20 patients with clinical Baylisascaris larva migrans, 137 patients with other parasitic infections (8 helminth and 4 protozoan), and 227 individuals with unknown/suspected parasitic infections. A sensitivity of 85% and a specificity of 86.9% were observed with the BpRAG1 ELISA, compared to only 39.4% specificity with the BPES ELISA. In addition, the BpRAG1 ELISA had a low degree of cross-reactivity with antibodies to Toxocara infection (25%), while the BPES antigen showed 90.6% cross-reactivity. Based on these results, the BpRAG1 antigen has a high degree of sensitivity and specificity and should be very useful and reliable in the diagnosis and seroepidemiology of Baylisascaris larva migrans by ELISA. PMID:21832102

  6. Recombinant Salmonella Expressing Burkholderia mallei LPS O Antigen Provides Protection in a Murine Model of Melioidosis and Glanders

    PubMed Central

    Moustafa, Dina A.; Scarff, Jennifer M.; Garcia, Preston P.; Cassidy, Sara K. B.; DiGiandomenico, Antonio; Waag, David M.; Inzana, Thomas J.; Goldberg, Joanna B.

    2015-01-01

    Burkholderia pseudomallei and Burkholderia mallei are the etiologic agents of melioidosis and glanders, respectively. These bacteria are highly infectious via the respiratory route and can cause severe and often fatal diseases in humans and animals. Both species are considered potential agents of biological warfare; they are classified as category B priority pathogens. Currently there are no human or veterinary vaccines available against these pathogens. Consequently efforts are directed towards the development of an efficacious and safe vaccine. Lipopolysaccharide (LPS) is an immunodominant antigen and potent stimulator of host immune responses. B. mallei express LPS that is structurally similar to that expressed by B. pseudomallei, suggesting the possibility of constructing a single protective vaccine against melioidosis and glanders. Previous studies of others have shown that antibodies against B. mallei or B. pseudomallei LPS partially protect mice against subsequent lethal virulent Burkholderia challenge. In this study, we evaluated the protective efficacy of recombinant Salmonella enterica serovar Typhimurium SL3261 expressing B. mallei O antigen against lethal intranasal infection with Burkholderia thailandensis, a surrogate for biothreat Burkholderia spp. in a murine model that mimics melioidosis and glanders. All vaccine-immunized mice developed a specific antibody response to B. mallei and B. pseudomallei O antigen and to B. thailandensis and were significantly protected against challenge with a lethal dose of B. thailandensis. These results suggest that live-attenuated SL3261 expressing B. mallei O antigen is a promising platform for developing a safe and effective vaccine. PMID:26148026

  7. Enhanced Protective Efficacy of Nonpathogenic Recombinant Leishmania tarentolae Expressing Cysteine Proteinases Combined with a Sand Fly Salivary Antigen

    PubMed Central

    Taheri, Tahereh; Taslimi, Yasaman; Doustdari, Fatemeh; Seyed, Negar; Torkashvand, Fatemeh; Meneses, Claudio; Papadopoulou, Barbara; Kamhawi, Shaden; Valenzuela, Jesus G.; Rafati, Sima

    2014-01-01

    Background Novel vaccination approaches are needed to prevent leishmaniasis. Live attenuated vaccines are the gold standard for protection against intracellular pathogens such as Leishmania and there have been new developments in this field. The nonpathogenic to humans lizard protozoan parasite, Leishmania (L) tarentolae, has been used effectively as a vaccine platform against visceral leishmaniasis in experimental animal models. Correspondingly, pre-exposure to sand fly saliva or immunization with a salivary protein has been shown to protect mice against cutaneous leishmaniasis. Methodology/Principal Findings Here, we tested the efficacy of a novel combination of established protective parasite antigens expressed by L. tarentolae together with a sand fly salivary antigen as a vaccine strategy against L. major infection. The immunogenicity and protective efficacy of different DNA/Live and Live/Live prime-boost vaccination modalities with live recombinant L. tarentolae stably expressing cysteine proteinases (type I and II, CPA/CPB) and PpSP15, an immunogenic salivary protein from Phlebotomus papatasi, a natural vector of L. major, were tested both in susceptible BALB/c and resistant C57BL/6 mice. Both humoral and cellular immune responses were assessed before challenge and at 3 and 10 weeks after Leishmania infection. In both strains of mice, the strongest protective effect was observed when priming with PpSP15 DNA and boosting with PpSP15 DNA and live recombinant L. tarentolae stably expressing cysteine proteinase genes. Conclusion/Significance The present study is the first to use a combination of recombinant L. tarentolae with a sand fly salivary antigen (PpSP15) and represents a novel promising vaccination approach against leishmaniasis. PMID:24675711

  8. Vaccinia virus recombinants encoding the truncated structural gene region of Venezuelan equine encephalitis virus (VEEV) give solid protection against peripheral challenge but only partial protection against airborne challenge with virulent VEEV.

    PubMed

    Phillpotts, R J; Lescott, T L; Jacobs, S C

    2000-10-01

    Vaccinia virus (VV) recombinants that contain the genes encoding the Venezuelan equine encephalitis virus (VEEV) structural gene region (C-E3-E2-6 K-E1) solidly protect mice against peripheral challenge with virulent VEEV, but provide only partial protection against airborne challenge. To improve upon these results we focussed on the principal antigens involved in protection. VV recombinants encoding the structural genes E3-E2-6 K-E1, E3-E2-6 K or 6 K-E1 were prepared and evaluated for their ability to protect Balb/c mice after a single dorsal scarification with 10(8) PFU against peripheral or airborne challenge with virulent VEEV. The antibody response was also examined. Our experiments provide new evidence that truncates of the VEEV structural region (E3-E2-6 K-E1, E3-E2-6 K), cloned and expressed in VV, protect against challenge with virulent virus. They also confirm the important role of E2 in protection. However, we were unable to improve upon previously reported levels of protection against airborne challenge. A substantial level of circulating antibodies and the presence of local IgA (not always induced by mucosal immunization) (Greenway et al., 1992) appear essential for protection against the airborne virus. Current VV-VEEV recombinants seem unable to elicit this level of immune response and further improvements are therefore required to increase the immunogenicity of VV-VEEV vaccines. PMID:11252667

  9. Intranasal priming with recombinant Bordetella pertussis for the induction of a systemic immune response against a heterologous antigen.

    PubMed Central

    Mielcarek, N; Cornette, J; Schacht, A M; Pierce, R J; Locht, C; Capron, A; Riveau, G

    1997-01-01

    One of the current goals in vaccine development is the noninvasive administration of protective antigens via mucosal surfaces. In this context, the gut-associated lymphoid tissues have already been extensively explored. Vaccination via the nasal route has only recently been the focus of intensive investigation, and no live vector specifically designed for the respiratory mucosa is yet available. In this study we show that intranasal administration of the recombinant Bordetella pertussis BPGR60, producing the Schistosoma mansoni 28-kDa glutathione S-transferase (Sm28GST) protective antigen fused to filamentous hemagglutinin, induces priming in mice for the production of serum antibodies. In addition to significant levels of anti-Sm28GST immunoglobulin A (IgA) antibodies, high levels of anti-Sm28GST serum antibodies were obtained after intranasal boost with the purified antigen or infection with S. mansoni following intranasal priming with BPGR60. These antibodies were of the IgG1, IgG2a, and IgG2b isotypes, suggesting a mixed immune response. No priming was observed in animals that had received nonrecombinant B. pertussis or purified Sm28GST, indicating specific priming by BPGR60. This priming was also evident in immune protection against S. mansoni challenge. Significant protection against worm burden and egg output was obtained in mice primed with BPGR60 and intranasally boosted with purified Sm28GST. A lower but still significant degree of protection against egg output was also obtained in mice infected with a single dose of BPGR60. These results indicate that intranasal administration of recombinant B. pertussis can prime for serum antibody responses against a foreign antigen and for heterologous protection. PMID:9009311

  10. Expressions of recombinant venom allergen, antigen 5 of yellowjacket (Vespula vulgaris) and paper wasp (Polistes annularis), in bacteria or yeast.

    PubMed

    Monsalve, R I; Lu, G; King, T P

    1999-08-01

    Antigen 5 is a major allergen of vespid venom. It has partial sequence identity with proteins from diverse sources. The biologic function of Ag 5 and its related proteins is not known. We are interested in the expression of Ag 5 with the native conformation of the natural protein since its B cell epitopes are mainly of the discontinuous type. When expressed in bacteria, recombinant Ag 5 formed an insoluble intracellular product, and it did not translocate from cytoplasm to periplasm by the addition of a pelB leader sequence to the cloned protein. When expressed in yeast Pichia pastoris, Ag 5 was secreted because the cloned protein contained a yeast alpha signal leader sequence. Recombinant Ag 5 from yeast was shown to have the native structure of the natural protein and the recombinant Ag 5 from bacteria did not. This was shown by comparison of their solubility, electrophoretic behavior, disulfide bond content, CD spectrum, and binding of IgE antibodies from allergic patients and IgG antibodies from mice immunized with natural Ag 5 or recombinant Ag 5s from yeast or bacteria. These studies were made with Ag 5s from yellowjacket (Vespula vulgaris) and paper wasp (Polistes annularis). PMID:10425162

  11. Recruitment of PfSET2 by RNA Polymerase II to Variant Antigen Encoding Loci Contributes to Antigenic Variation in P. falciparum

    PubMed Central

    Kwiatkowski, Dacia L.; Pandarinath, Chethan; Dahan-Pasternak, Noa; Dzikowski, Ron; Deitsch, Kirk W.

    2014-01-01

    Histone modifications are important regulators of gene expression in all eukaryotes. In Plasmodium falciparum, these epigenetic marks regulate expression of genes involved in several aspects of host-parasite interactions, including antigenic variation. While the identities and genomic positions of many histone modifications have now been cataloged, how they are targeted to defined genomic regions remains poorly understood. For example, how variant antigen encoding loci (var) are targeted for deposition of unique histone marks is a mystery that continues to perplex the field. Here we describe the recruitment of an ortholog of the histone modifier SET2 to var genes through direct interactions with the C-terminal domain (CTD) of RNA polymerase II. In higher eukaryotes, SET2 is a histone methyltransferase recruited by RNA pol II during mRNA transcription; however, the ortholog in P. falciparum (PfSET2) has an atypical architecture and its role in regulating transcription is unknown. Here we show that PfSET2 binds to the unphosphorylated form of the CTD, a property inconsistent with its recruitment during mRNA synthesis. Further, we show that H3K36me3, the epigenetic mark deposited by PfSET2, is enriched at both active and silent var gene loci, providing additional evidence that its recruitment is not associated with mRNA production. Over-expression of a dominant negative form of PfSET2 designed to disrupt binding to RNA pol II induced rapid var gene expression switching, confirming both the importance of PfSET2 in var gene regulation and a role for RNA pol II in its recruitment. RNA pol II is known to transcribe non-coding RNAs from both active and silent var genes, providing a possible mechanism by which it could recruit PfSET2 to var loci. This work unifies previous reports of histone modifications, the production of ncRNAs, and the promoter activity of var introns into a mechanism that contributes to antigenic variation by malaria parasites. PMID:24391504

  12. Fas Ligand DNA Enhances a Vaccination Effect by Coadministered DNA Encoding a Tumor Antigen through Augmenting Production of Antibody against the Tumor Antigen

    PubMed Central

    Zhong, Boya; Ma, Guangyu; Sato, Ayako; Shimozato, Osamu; Liu, Hongdan; Shingyoji, Masato; Tada, Yuji; Tatsumi, Koichiro; Shimada, Hideaki; Hiroshima, Kenzo; Tagawa, Masatoshi

    2015-01-01

    Interaction of Fas and Fas ligand (FasL) plays an important role in the regulation of immune responses by inducing apoptosis of activated cells; however, a possible role of FasL in DNA vaccination has not been well understood. We examined whether administration of DNA encoding FasL gene enhanced antitumor effects in mice that were vaccinated with DNA expressing a putative tumor antigen gene, β-galactosidase (β-gal). Growth of β-gal-positive Colon 26 tumors was retarded in the syngeneic mice immunized with β-gal and FasL DNA compared with those vaccinated with β-gal or FasL DNA. We did not detect increased numbers of β-gal-specific CD8+ T cells in lymph node of mice that received combination of β-gal and FasL DNA, but amounts of anti-β-gal antibody increased with the combination but not with β-gal or FasL DNA injection alone. Subtype analysis of anti-β-gal antibody produced by the combination of β-gal and FasL DNA or β-gal DNA injection showed that IgG2a amounts were greater in mice injected with both DNA than those with β-gal DNA alone, but IgG2b amounts were lower in both DNA-injected than β-gal DNA-injected mice. These data suggest that FasL is involved in boosting humoral immunity against a gene product encoded by coinjected DNA and enhances the vaccination effects. PMID:25759847

  13. Molecular cloning of cDNA encoding a novel platelet-endothelial cell tetra-span antigen, PETA-3.

    PubMed

    Fitter, S; Tetaz, T J; Berndt, M C; Ashman, L K

    1995-08-15

    Platelet-endothelial cell tetra-span antigen (PETA-3) was originally identified as a novel human platelet surface glycoprotein, gp27, which was detected by a monoclonal antibody (MoAb), 14A2.H1. Although this glycoprotein is present in low abundance on the platelet surface, MoAb 14A2.H1 stimulates platelet aggregation and mediator release. We now report isolation of a cDNA clone encoding PETA-3 from a library derived from the megakaryoblastic leukemia cell line MO7e. The clone encodes an open reading frame of 253 amino acids that displays 25% to 30% amino acid sequence identity with several members of the newly defined Tetraspan, or Transmembrane 4 superfamily. These proteins consist of four conserved putative transmembrane domains with a large divergent extracellular loop between the third and fourth membrane-spanning regions. PETA-3 has a single consensus sequence for N-linked glycosylation located in this extracellular loop. A single PETA-3 RNA transcript (1.6 kb) was detected in RNA isolated from MO7e cells, bone marrow stromal cells, the C11 endothelial cell line, and several myeloid leukemia cell lines. No transcript was detected in the lymphoblastoid cell lines MOLT-4 and BALM-1. This pattern correlates well with previous protein expression data. Northern blot analysis of RNA from a range of human tissues indicated that the transcript was present in most tissues, the notable exception being brain. PMID:7632941

  14. The PANE1 gene encodes a novel human minor histocompatibility antigen that is selectively expressed in B-lymphoid cells and B-CLL

    PubMed Central

    Brickner, Anthony G.; Evans, Anne M.; Mito, Jeffrey K.; Xuereb, Suzanne M.; Feng, Xin; Nishida, Tetsuya; Fairfull, Liane; Ferrell, Robert E.; Foon, Kenneth A.; Hunt, Donald F.; Shabanowitz, Jeffrey; Engelhard, Victor H.; Riddell, Stanley R.; Warren, Edus H.

    2006-01-01

    Minor histocompatibility antigens (mHAg's) are peptides encoded by polymorphic genes that are presented by major histocompatibility complex (MHC) molecules and recognized by T cells in recipients of allogeneic hematopoietic cell transplants. Here we report that an alternative transcript of the proliferation-associated nuclear element 1 (PANE1) gene encodes a novel human leukocyte antigen (HLA)-A*0301-restricted mHAg that is selectively expressed in B-lymphoid cells. The antigenic peptide is entirely encoded within a unique exon not present in other PANE1 transcripts. Sequencing of PANE1 alleles in mHAg-positive and mHAg-negative cells demonstrates that differential T-cell recognition is due to a single nucleotide polymorphism within the variant exon that replaces an arginine codon with a translation termination codon. The PANE1 transcript that encodes the mHAg is expressed at high levels in resting CD19+ B cells and B-lineage chronic lymphocytic leukemia (B-CLL) cells, and at significantly lower levels in activated B cells. Activation of B-CLL cells through CD40 ligand (CD40L) stimulation decreases expression of the mHAg-encoding PANE1 transcript and reciprocally increases expression of PANE1 transcripts lacking the mHAg-encoding exon. These studies suggest distinct roles for different PANE1 isoforms in resting compared with activated CD19+ cells, and identify PANE1 as a potential therapeutic target in B-CLL. PMID:16391015

  15. Development and Comparative Evaluation of a Plate Enzyme-Linked Immunosorbent Assay Based on Recombinant Outer Membrane Antigens Omp28 and Omp31 for Diagnosis of Human Brucellosis

    PubMed Central

    Tiwari, Sapana; Kumar, Ashu; Mangalgi, Smita; Rathod, Vedika; Prakash, Archana; Barua, Anita; Arora, Sonia; Sathyaseelan, Kannusamy

    2013-01-01

    Brucellosis is an important zoonotic infectious disease of humans and livestock with worldwide distribution and is caused by bacteria of the genus Brucella. The diagnosis of brucellosis always requires laboratory confirmation by either isolation of pathogens or detection of specific antibodies. The conventional serological tests available for the diagnosis of brucellosis are less specific and show cross-reactivity with other closely related organisms. These tests also necessitate the handling of Brucella species for antigen preparation. Therefore, there is a need to develop reliable, rapid, and user-friendly systems for disease diagnosis and alternatives to vaccine approaches. Keeping in mind the importance of brucellosis as an emerging infection and the prevalence in India, we carried out the present study to compare the recombinant antigens with the native antigens (cell envelope and sonicated antigen) of Brucella for diagnosis of human brucellosis by an indirect plate enzyme-linked immunosorbent assay (ELISA). Recombinant outer membrane protein 28 (rOmp28) and rOmp31 antigens were cloned, expressed, and purified in the bacterial expression system, and the purified proteins were used as antigens. Indirect plate ELISAs were then performed and standardized for comparison of the reactivities of recombinant and native antigens against the 433 clinical samples submitted for brucellosis testing, 15 culture-positive samples, and 20 healthy donor samples. The samples were separated into four groups based on their positivity to rose bengal plate agglutination tests (RBPTs), standard tube agglutination tests (STATs), and 2-mercaptoethanol (2ME) tests. The sensitivities and specificities of all the antigens were calculated, and the rOmp28 antigen was found to be more suitable for the clinical diagnosis of brucellosis than the rOmp31 antigen and native antigens. The rOmp28-based ELISA showed a very high degree of agreement with the conventional agglutination tests and

  16. The generation and analyses of a novel combination of recombinant adenovirus vaccines targeting three tumor antigens as an immunotherapeutic

    PubMed Central

    Gabitzsch, Elizabeth S.; Tsang, Kwong Yok; Palena, Claudia; David, Justin M.; Fantini, Massimo; Kwilas, Anna; Rice, Adrian E.; Latchman, Yvette; Hodge, James W.; Gulley, James L.; Madan, Ravi A.; Heery, Christopher R.; Balint, Joseph P.

    2015-01-01

    Phenotypic heterogeneity of human carcinoma lesions, including heterogeneity in expression of tumor-associated antigens (TAAs), is a well-established phenomenon. Carcinoembryonic antigen (CEA), MUC1, and brachyury are diverse TAAs, each of which is expressed on a wide range of human tumors. We have previously reported on a novel adenovirus serotype 5 (Ad5) vector gene delivery platform (Ad5 [E1-, E2b-]) in which regions of the early 1 (E1), early 2 (E2b), and early 3 (E3) genes have been deleted. The unique deletions in this platform result in a dramatic decrease in late gene expression, leading to a marked reduction in host immune response to the vector. Ad5 [E1-, E2b-]-CEA vaccine (ETBX-011) has been employed in clinical studies as an active vaccine to induce immune responses to CEA in metastatic colorectal cancer patients. We report here the development of novel recombinant Ad5 [E1-, E2b-]-brachyury and-MUC1 vaccine constructs, each capable of activating antigen-specific human T cells in vitro and inducing antigen-specific CD4+ and CD8+ T cells in vaccinated mice. We also describe the use of a combination of the three vaccines (designated Tri-Ad5) of Ad5 [E1-, E2b-]-CEA, Ad5 [E1-, E2b-]-brachyury and Ad5 [E1-, E2b-]-MUC1, and demonstrate that there is minimal to no “antigenic competition” in in vitro studies of human dendritic cells, or in murine vaccination studies. The studies reported herein support the rationale for the application of Tri-Ad5 as a therapeutic modality to induce immune responses to a diverse range of human TAAs for potential clinical studies. PMID:26374823

  17. Vaccination using recombinants influenza and adenoviruses encoding amastigote surface protein-2 are highly effective on protection against Trypanosoma cruzi infection.

    PubMed

    Barbosa, Rafael Polidoro Alves; Filho, Bruno Galvão; Dos Santos, Luara Isabela; Junior, Policarpo Ademar Sales; Marques, Pedro Elias; Pereira, Rafaela Vaz Sousa; Cara, Denise Carmona; Bruña-Romero, Oscar; Rodrigues, Maurício Martins; Gazzinelli, Ricardo Tostes; Machado, Alexandre Vieira

    2013-01-01

    In the present study we evaluated the protection raised by immunization with recombinant influenza viruses carrying sequences coding for polypeptides corresponding to medial and carboxi-terminal moieties of Trypanosoma cruzi ´s amastigote surface protein 2 (ASP2). Those viruses were used in sequential immunization with recombinant adenovirus (heterologous prime-boost immunization protocol) encoding the complete sequence of ASP2 (Ad-ASP2) in two mouse strains (C57BL/6 and C3H/He). The CD8 effector response elicited by this protocol was comparable to that observed in mice immunized twice with Ad-ASP2 and more robust than that observed in mice that were immunized once with Ad-ASP2. Whereas a single immunization with Ad-ASP2 sufficed to completely protect C57BL/6 mice, a higher survival rate was observed in C3H/He mice that were primed with recombinant influenza virus and boosted with Ad-ASP2 after being challenged with T. cruzi. Analyzing the phenotype of CD8+ T cells obtained from spleen of vaccinated C3H/He mice we observed that heterologous prime-boost immunization protocol elicited more CD8+ T cells specific for the immunodominant epitope as well as a higher number of CD8+ T cells producing TNF-α and IFN-γ and a higher mobilization of surface marker CD107a. Taken together, our results suggest that immunodominant subpopulations of CD8+ T elicited after immunization could be directly related to degree of protection achieved by different immunization protocols using different viral vectors. Overall, these results demonstrated the usefulness of recombinant influenza viruses in immunization protocols against Chagas Disease. PMID:23637908

  18. DDX3Y encodes a class I MHC–restricted H-Y antigen that is expressed in leukemic stem cells

    PubMed Central

    Rosinski, Kellie V.; Fujii, Nobuharu; Mito, Jeffrey K.; Koo, Kevin K. W.; Xuereb, Suzanne M.; Sala-Torra, Olga; Gibbs, James S.; Radich, Jerald P.; Akatsuka, Yoshiki; Van den Eynde, Benoît J.; Riddell, Stanley R.

    2008-01-01

    The Y chromosome encodes male-specific minor histocompatibility (H-Y) antigens that stimulate T- and B-lymphocyte responses after sex-mismatched allogeneic hematopoietic cell transplantation (HCT). A CD8+ cytotoxic T lymphocyte (CTL) clone that recognizes a novel HLA-B*2705–restricted H-Y antigen encoded by the DDX3Y gene was isolated from a male who had received a hematopoietic cell graft from his human leukocyte antigen (HLA)–identical sister. The antigenic peptide is a decamer that differs from the homologous DDX3X-encoded peptide at 4 positions. Expression of DDX3Y and of the H-Y epitope that it encodes was examined by quantitative polymerase chain reaction (PCR) and by CTL recognition assays. Expression of DDX3Y is detected in all myeloid and lymphoid leukemic cells that carry an intact Y chromosome. Moreover, the DDX3Y-encoded H-Y epitope is presented on the surface of both myeloid and lymphoid leukemic cells from male HLA-B*2705+ patients. DDX3Y-specific CTLs prevent engraftment of human acute leukemia in nonobese diabetic/severe combined immune deficient mice, demonstrating that the DDX3Y-encoded H-Y antigen is also expressed in leukemic stem cells. These results demonstrate that CD8+ T-cell responses against DDX3Y have the potential to contribute to graft-versus-leukemia (GVL) activity after female into male allogeneic HCT. This study is registered at http://clinicaltrials.gov as NCT00107354. PMID:18299450

  19. Control of Boophilus microplus ticks in cattle calves by immunization with a recombinant Bm86 glucoprotein antigen preparation.

    PubMed

    Khalaf-Allah, S S

    1999-06-01

    Forty Egyptian native cattle calves of 4-6 months old randomly allocated into two groups of twenty animals each were used to assess the effect of immunization of animals with a recombinant Bm86 antigen derived from Boophilus microplus ticks on induction of immunity that could protect calves during tick season. The immunization protocol involved two injections administered intramuscularly, the first was applied with complete Freund's adjuvant and the second was given with incomplete Freund's adjuvant two months later. Control calves were given saline plus adjuvant. Immunization reduced the number of adult ticks developing from a subsequent challenge infestation by 78% in immunized calves. Vaccination also, significantly reduced the weight of adult ticks in immunized calves (30.51%). The results of skin delayed hypersensitivity reaction revealed that the diameter of sites injected with the recombinant Bm86 antigen was significantly larger in immunized calves than those in controls. Analysis of the immune response indicated that there was a significant increase in the level of IgG and IgA antibodies in serum of immunized calves and protection from reinfestation was correlated with the levels of circulating antibodies. PMID:10422372

  20. Recombinant Pvs48/45 Antigen Expressed in E. coli Generates Antibodies that Block Malaria Transmission in Anopheles albimanus Mosquitoes

    PubMed Central

    Arévalo-Herrera, Myriam; Vallejo, Andrés F.; Rubiano, Kelly; Solarte, Yezid; Marin, Catherin; Castellanos, Angélica; Céspedes, Nora; Herrera, Sócrates

    2015-01-01

    Transmission of malaria parasites from humans to Anopheles mosquitoes can be inhibited by specific antibodies elicited during malaria infection, which target surface Plasmodium gametocyte/gamete proteins. Some of these proteins may have potential for vaccine development. Pvs48/45 is a P. vivax gametocyte surface antigen orthologous to Pfs48/45, which may play a role during parasite fertilization and thus has potential for transmission blocking (TB) activity. Here we describe the expression of a recombinant Pvs48/45 protein expressed in Escherichia coli as a ∼60kDa construct which we tested for antigenicity using human sera and for its immunogenicity and transmission blocking activity of specific anti-mouse and anti-monkey Pvs48/45 antibodies. The protein reacted with sera of individuals from malaria-endemic areas and in addition induced specific IgG antibody responses in BALB/c mice and Aotus l. griseimembra monkeys. Sera from both immunized animal species recognized native P. vivax protein in Western blot (WB) and immunofluorescence assays. Moreover, sera from immunized mice and monkeys produced significant inhibition of parasite transmission to An. Albimanus mosquitoes as shown by membrane feeding assays. Results indicate the presence of reactive epitopes in the Pvs48/45 recombinant product that induce antibodies with TB activity. Further testing of this protein is ongoing to determine its vaccine potential. PMID:25775466

  1. Recombinant Leishmania (Leishmania) infantum Ecto-Nucleoside Triphosphate Diphosphohydrolase NTPDase-2 as a new antigen in canine visceral leishmaniasis diagnosis.

    PubMed

    de Souza, Ronny Francisco; Dos Santos, Yaro Luciolo; de Souza Vasconcellos, Raphael; Borges-Pereira, Lucas; Caldas, Ivo Santana; de Almeida, Márcia Rogéria; Bahia, Maria Terezinha; Fietto, Juliana Lopes Rangel

    2013-01-01

    Canine visceral leishmaniasis is an important public health concern. In the epidemiological context of human visceral leishmaniasis, dogs are considered the main reservoir of Leishmania parasites; therefore, dogs must be epidemiologically monitored constantly in endemic areas. Furthermore, dog to human transmission has been correlated with emerging urbanization and increasing rates of leishmaniasis infection worldwide. Leishmania (Leishmania) infantum (L. chagasi) is the etiologic agent of visceral leishmaniasis in the New World. In this work, a new L. (L.) infantum (L. chagasi) recombinant antigen, named ATP diphosphohydrolase (rLic-NTPDase-2), intended for use in the immunodiagnosis of CVL was produced and validated. The extracellular domain of ATP diphosphohydrolase was cloned and expressed in the pET21b-Escherichia coli expression system. Indirect ELISA assays were used to detect the purified rLic-NTPDase-2 antigen using a standard canine sera library. This library contained CVL-positive samples, leishmaniasis-negative samples and samples from Trypanosoma cruzi-infected dogs. The results show a high sensitivity of 100% (95% CI=92.60-100.0%) and a high specificity of 100% (95% CI=86.77-100.0%), with a high degree of confidence (k=1). These findings demonstrate the potential use of this recombinant protein in immune diagnosis of canine leishmaniasis and open the possibility of its application to other diagnostic approaches, such as immunochromatography fast lateral flow assays and human leishmaniasis diagnosis. PMID:23022017

  2. Production of antigens in Chlamydomonas reinhardtii: green microalgae as a novel source of recombinant proteins.

    PubMed

    Fuhrmann, Markus

    2004-01-01

    Recombinant small-scale proteins are produced in a number of systems, from bacteria like Escherichia coli, through lower eukaryotes like baker's yeast, up to mammalian cell cultures. However, the need for safe and cheap sources of large amounts of recombinant proteins for different purposes, including material sciences, diagnostics, and, of course, medical therapy, has forced the development of alternative production systems. Green microalgae are cheap and easily grown and offer a high protein content, which would seem to make them ideal hosts for the large-scale sustainable production of recombinant proteins in the future. In selected species, recombinant DNA can be introduced into the genomes of the nucleus, the chloroplast, and even the mitochondria, and thus the system offers both prokaryotic (chloroplast, mitochondria) and eukaryotic translation systems for a tailored expression of virtually any protein. PMID:14959830

  3. Recombinant plasmids for encoding restriction enzymes DpnI and DpnII of streptococcus pneumontae

    DOEpatents

    Lacks, Sanford A.

    1990-01-01

    Chromosomal DNA cassettes containing genes encoding either the DpnI or DpnII restriction endonucleases from Streptococcus pneumoniae are cloned into a streptococcal vector, pLS101. Large amounts of the restriction enzymes are produced by cells containing the multicopy plasmids, pLS202 and pLS207, and their derivatives pLS201, pLS211, pLS217, pLS251 and pLS252.

  4. Recombinant plasmids for encoding restriction enzymes DpnI and DpnII of Streptococcus pneumontae

    DOEpatents

    Lacks, S.A.

    1990-10-02

    Chromosomal DNA cassettes containing genes encoding either the DpnI or DpnII restriction endonucleases from Streptococcus pneumoniae are cloned into a streptococcal vector, pLS101. Large amounts of the restriction enzymes are produced by cells containing the multicopy plasmids, pLS202 and pLS207, and their derivatives pLS201, pLS211, pLS217, pLS251 and pLS252. 9 figs.

  5. A novel recombinant BCG vaccine encoding eimeria tenella rhomboid and chicken IL-2 induces protective immunity against coccidiosis.

    PubMed

    Wang, Qiuyue; Chen, Lifeng; Li, Jianhua; Zheng, Jun; Cai, Ning; Gong, Pengtao; Li, Shuhong; Li, He; Zhang, Xichen

    2014-06-01

    A novel recombinant Bacille Calmette-Guerin (rBCG) vaccine co-expressed Eimeria tenella rhomboid and cytokine chicken IL-2 (chIL-2) was constructed, and its efficacy against E. tenella challenge was observed. The rhomboid gene of E. tenella and chIL-2 gene were subcloned into integrative expression vector pMV361, producing vaccines rBCG pMV361-rho and pMV361-rho-IL2. Animal experiment via intranasal and subcutaneous route in chickens was carried out to evaluate the immune efficacy of the vaccines. The results indicated that these rBCG vaccines could obviously alleviate cacal lesions and oocyst output. Intranasal immunization with pMV361-rho and pMV361-rho-IL2 elicited better protective immunity against E. tenella than subcutaneous immunization. Splenocytes from chickens immunized with either rBCG pMV361-rho and pMV361-rho-IL2 had increased CD4(+) and CD8(+) cell production. Our data indicate recombinant BCG is able to impart partial protection against E. tenella challenge and co-expression of cytokine with antigen was an effective strategy to improve vaccine immunity. PMID:25031464

  6. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA) Induce Protective Immune Responses in Dogs.

    PubMed

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-05-01

    Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA) or its carboxy terminal part LaPSA-12S (Cter-rPSA), combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates. PMID:27223609

  7. Recombinant Forms of Leishmania amazonensis Excreted/Secreted Promastigote Surface Antigen (PSA) Induce Protective Immune Responses in Dogs

    PubMed Central

    Petitdidier, Elodie; Pagniez, Julie; Papierok, Gérard; Vincendeau, Philippe; Lemesre, Jean-Loup; Bras-Gonçalves, Rachel

    2016-01-01

    Preventive vaccination is a highly promising strategy for interrupting leishmaniasis transmission that can, additionally, contribute to elimination. A vaccine formulation based on naturally excreted secreted (ES) antigens was prepared from L. infantum promastigote culture supernatant. This vaccine achieved successful results in Phase III trials and was licensed and marketed as CaniLeish. We recently showed that newly identified ES promastigote surface antigen (PSA), from both viable promastigotes and axenically-grown amastigotes, represented the major constituent and the highly immunogenic antigen of L. infantum and L. amazonensis ES products. We report here that three immunizations with either the recombinant ES LaPSA-38S (rPSA) or its carboxy terminal part LaPSA-12S (Cter-rPSA), combined with QA-21 as adjuvant, confer high levels of protection in naive L. infantum-infected Beagle dogs, as checked by bone marrow parasite absence in respectively 78.8% and 80% of vaccinated dogs at 6 months post-challenge. The parasite burden in infected vaccinated dogs was significantly reduced compared to placebo group, as measured by q-PCR. Moreover, our results reveal humoral and cellular immune response clear-cut differences between vaccinated and control dogs. An early increase in specific IgG2 antibodies was observed in rPSA/QA-21- and Cter-rPSA/QA-21-immunized dogs only. They were found functionally active in vitro and were highly correlated with vaccine protection. In vaccinated protected dogs, IFN-γ and NO productions, as well as anti-leishmanial macrophage activity, were increased. These data strongly suggest that ES PSA or its carboxy-terminal part, in recombinant forms, induce protection in a canine model of zoonotic visceral leishmaniasis by inducing a Th1-dominant immune response and an appropriate specific antibody response. These data suggest that they could be considered as important active components in vaccine candidates. PMID:27223609

  8. Protection against murine listeriosis by an attenuated recombinant Salmonella typhimurium vaccine strain that secretes the naturally somatic antigen superoxide dismutase.

    PubMed Central

    Hess, J; Dietrich, G; Gentschev, I; Miko, D; Goebel, W; Kaufmann, S H

    1997-01-01

    A recombinant (r)-Salmonella typhimurium aroA vaccine strain was constructed which secretes the naturally somatic protein of Listeria monocytogenes, superoxide dismutase (SOD), by the HlyB/HlyD/TolC export machinery. Vaccine efficacy of the SOD-bearing carrier strain was compared with that of the p60-secreting construct, S. typhimurium p60s (J. Hess, I. Gentschev, D. Miko, M. Welzel, C. Ladel, W. Goebel, and S. H. E. Kaufmann, Proc. Natl. Acad. Sci. USA 93:1458-1463, 1996). Vaccination of mice with both constructs induced protection against a lethal challenge with the intracellular pathogen, L. monocytogenes. While the somatic listerial antigen, SOD, is immunologically uncharacterized, the naturally secreted protein of L. monocytogenes, p60, is known to be highly immunogenic. Our data emphasize the high vaccine potential of r-Salmonella constructs secreting antigens of somatic or secreted origin. Moreover, they suggest that the HlyB/HlyD/TolC-based antigen delivery system with attenuated Salmonella spp. as the carrier is capable of potentiating the immune response against foreign proteins independent from their immunogenicity in and display by the natural host. PMID:9119463

  9. Protection against murine listeriosis by an attenuated recombinant Salmonella typhimurium vaccine strain that secretes the naturally somatic antigen superoxide dismutase.

    PubMed

    Hess, J; Dietrich, G; Gentschev, I; Miko, D; Goebel, W; Kaufmann, S H

    1997-04-01

    A recombinant (r)-Salmonella typhimurium aroA vaccine strain was constructed which secretes the naturally somatic protein of Listeria monocytogenes, superoxide dismutase (SOD), by the HlyB/HlyD/TolC export machinery. Vaccine efficacy of the SOD-bearing carrier strain was compared with that of the p60-secreting construct, S. typhimurium p60s (J. Hess, I. Gentschev, D. Miko, M. Welzel, C. Ladel, W. Goebel, and S. H. E. Kaufmann, Proc. Natl. Acad. Sci. USA 93:1458-1463, 1996). Vaccination of mice with both constructs induced protection against a lethal challenge with the intracellular pathogen, L. monocytogenes. While the somatic listerial antigen, SOD, is immunologically uncharacterized, the naturally secreted protein of L. monocytogenes, p60, is known to be highly immunogenic. Our data emphasize the high vaccine potential of r-Salmonella constructs secreting antigens of somatic or secreted origin. Moreover, they suggest that the HlyB/HlyD/TolC-based antigen delivery system with attenuated Salmonella spp. as the carrier is capable of potentiating the immune response against foreign proteins independent from their immunogenicity in and display by the natural host. PMID:9119463

  10. Cellular and humoral immune responses to viral antigens create barriers to lung-directed gene therapy with recombinant adenoviruses.

    PubMed Central

    Yang, Y; Li, Q; Ertl, H C; Wilson, J M

    1995-01-01

    Recombinant adenoviruses are an attractive vehicle for gene therapy to the lung in the treatment of cystic fibrosis (CF). First-generation viruses deleted of E1a and E1b transduce genes into airway epithelial cells in vivo; however, expression of the transgene is transient and associated with substantial inflammatory responses, and gene transfer is significantly reduced following a second administration of the virus. In this study, we have used mice deficient in immunological effector functions in combination with adoptive and passive transfer techniques to define antigen-specific cellular and humoral immune responses that underlie these important limitations. Our studies indicate that major histocompatibility complex class I-restricted CD8+ cytotoxic T lymphocytes are activated in response to newly synthesized antigens, leading to destruction of virus infected cells and loss of transgene expression. Major histocompatibility complex class II-associated presentation of exogenous viral antigens activates CD4+ T-helper (TH) cells of the TH1 subset and, to a lesser extent, of the TH2 subset. CD4+ cell-mediated responses are insufficient in the absence of cytotoxic T cells to completely eliminate transgene containing cells; however, they contribute to the formation of neutralizing antibodies in the airway which block subsequent adenovirus-mediated gene transfer. Definition of immunological barriers to gene therapy of cystic fibrosis should facilitate the design of rational strategies to overcome them. PMID:7884845

  11. Production of Toxocara cati TES-120 Recombinant Antigen and Comparison with its T. canis Homolog for Serodiagnosis of Toxocariasis.

    PubMed

    Zahabiun, Farzaneh; Sadjjadi, Seyed Mahmoud; Yunus, Muhammad Hafiznur; Rahumatullah, Anizah; Moghaddam, Mohammad Hosein Falaki; Saidin, Syazwan; Noordin, Rahmah

    2015-08-01

    Toxocariasis is a cosmopolitan zoonotic disease caused by the infective larvae of Toxocara canis and T. cati. Diagnosis in humans is usually based on clinical symptoms and serology. Immunoglobulin G (IgG)-enzyme-linked immunosorbent assay kits using T. canis excretory-secretory (TES) larval antigens are commonly used for serodiagnosis. Differences in the antigens of the two Toxocara species may influence the diagnostic sensitivity of the test. In this study, T. cati recombinant TES-120 (rTES-120) was cloned, expressed, and compared with its T. canis homolog in an IgG4-western blot. The diagnostic sensitivity and specificity of T. cati rTES-120 were 70% (33/47) and 100% (39/39), respectively. T. canis rTES-120 showed 57.4% sensitivity and 94.4% specificity. When the results of assays using rTES-120 of both species were considered, the diagnostic sensitivity was 76%. This study shows that using antigens from both Toxocara species may improve the serodiagnosis of toxocariasis. PMID:26033026

  12. Vaccine potential of recombinant antigens of Theileria annulata and Hyalomma anatolicum anatolicum against vector and parasite.

    PubMed

    Jeyabal, L; Kumar, Binod; Ray, Debdatta; Azahahianambi, Palavesam; Ghosh, Srikanta

    2012-09-10

    In an attempt to develop vaccine against Hyalomma anatolicum anatolicum and Theileria annulata, three antigens were expressed in prokaryotic expression system and protective potentiality of the antigens was evaluated in cross bred calves. Two groups (grs. 1 and 4) of male cross-bred (Bos indicus × Bos taurus) calves were immunized with rHaa86, a Bm86 ortholog of H. a. anatolicum, while one group of calves (gr. 2) were immunized with cocktails of two antigens viz., surface antigens of T. annulata (rSPAG1, rTaSP). One group each was kept as negative controls (grs. 3 and 5). The animals of groups 1, 2 and 3 were challenged with T. annulata infected H. a. anatolicum adults while the animals of groups 1, 3, 4 and 5 were challenged with uninfected adult ticks. A significantly high (p<0.05) antibody responses to all the three antigens were detected in immunized calves, but the immune response was comparatively higher with rHaa86 followed by rTaSP and rSPAG1. Upon challenge with T. annulata infected ticks, animals of all groups showed symptoms of the disease but there was 50% survival of calves of group 1 while all non immunized control calves (group 3) and rSPAG1+rTaSP immunized calves died. The rHaa86 antigen was found efficacious to protect calves against more than 71.4-75.5% of the challenge infestation. The experiment has given a significant clue towards the development of rHaa86 based vaccine against both H. a. anatolicum and T. annulata. PMID:22546546

  13. Expression and self-assembly of recombinant capsid protein from the antigenically distinct Hawaii human calicivirus.

    PubMed Central

    Green, K Y; Kapikian, A Z; Valdesuso, J; Sosnovtsev, S; Treanor, J J; Lew, J F

    1997-01-01

    The Norwalk and Hawaii viruses are antigenically distinct members of the family Caliciviridae and are considered to be important etiologic agents of epidemic gastroenteritis, with most studies focusing on the role of Norwalk virus. To further investigate the importance of Hawaii virus, Hawaii virus-like particles (VLPs) were produced by expression of its capsid protein in the baculovirus system and these VLPs were used as the antigen in an enzyme-linked immunosorbent assay that was efficient in the detection of a serologic response to Hawaii virus. The ready availability of Hawaii VLPs should enable larger-scale epidemiological studies to further elucidate the importance of this agent. PMID:9196224

  14. Site-specific chemical modification of recombinant proteins produced in mammalian cells by using the genetically encoded aldehyde tag.

    PubMed

    Wu, Peng; Shui, Wenqing; Carlson, Brian L; Hu, Nancy; Rabuka, David; Lee, Julia; Bertozzi, Carolyn R

    2009-03-01

    The properties of therapeutic proteins can be enhanced by chemical modification. Methods for site-specific protein conjugation are critical to such efforts. Here, we demonstrate that recombinant proteins expressed in mammalian cells can be site-specifically modified by using a genetically encoded aldehyde tag. We introduced the peptide sequence recognized by the endoplasmic reticulum (ER)-resident formylglycine generating enzyme (FGE), which can be as short as 6 residues, into heterologous proteins expressed in mammalian cells. Cotranslational modification of the proteins by FGE produced products bearing a unique aldehyde group. Proteins bearing this "aldehyde tag" were chemically modified by selective reaction with hydrazide- or aminooxy-functionalized reagents. We applied the technique to site-specific modification of monoclonal antibodies, the fastest growing class of biopharmaceuticals, as well as membrane-associated and cytosolic proteins expressed in mammalian cells. PMID:19202059

  15. Lentiviral vector encoding ubiquitinated hepatitis B core antigen induces potent cellular immune responses and therapeutic immunity in HBV transgenic mice.

    PubMed

    Dai, Shenglan; Zhuo, Meng; Song, Linlin; Chen, Xiaohua; Yu, Yongsheng; Zang, Guoqing; Tang, Zhenghao

    2016-07-01

    Predominant T helper cell type 1 (Th1) immune responses accompanied by boosted HBV-specific cytotoxic T lymphocyte (CTL) activity are essential for the clearance of hepatitis B virus (HBV) in chronic hepatitis B (CHB) patients. Ubiquitin (Ub) serves as a signal for the target protein to be recognized and degraded through the ubiquitin-proteasome system (UPS). Ubiquitinated hepatitis B core antigen (Ub-HBcAg) has been proved to be efficiently degraded into the peptides, which can be presented by major histocompatibility complex (MHC) class I resulting in stimulating cell-mediated responses. In the present study, lentiviral vectors encoding Ub-HBcAg (LV-Ub-HBcAg) were designed and constructed as a therapeutic vaccine for immunotherapy. HBcAg-specific cellular immune responses and anti-viral effects induced by LV-Ub-HBcAg were evaluated in HBV transgenic mice. We demonstrated that immunization with LV-Ub-HBcAg promoted the secretion of cytokines interleukin-2 (IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), generated remarkably high percentages of IFN-γ-secreting CD8(+) T cells and CD4(+) T cells, and enhanced HBcAg-specific CTL activity in HBV transgenic mice. More importantly, vaccination with LV-Ub-HBcAg could efficiently decreased the levels of serum hepatitis B surface antigen (HBsAg), HBV DNA and the expression of HBsAg and HBcAg in liver tissues of HBV transgenic mice. In addition, LV-Ub-HBcAg could upregulate the expression of T cell-specific T-box transcription factor (T-bet) and downregulate the expression of GATA-binding protein 3 (GATA-3) in spleen T lymphocytes. The therapeutic vaccine LV-Ub-HBcAg could break immune tolerance, and induce potent HBcAg specific cellular immune responses and therapeutic effects in HBV transgenic mice. PMID:26874581

  16. Phosphorylation in vitro of Escherichia coli-produced 235R and 266R tumor antigens encoded by human adenovirus type 12 early transformation region 1A.

    PubMed Central

    Lucher, L A; Loewenstein, P M; Green, M

    1985-01-01

    The tumor (T) antigens encoded by the human adenovirus early transforming region 1A (E1A) are gene regulatory proteins whose functions can immortalize cells. We have recently described the synthesis in Escherichia coli and the purification of the complete T antigens encoded by the adenovirus type 12 (Ad12) E1A 12S mRNA (235-residue [235R] T antigen) and 13S mRNA (266R T antigen). In this study, we show that the Ad12 E1A T antigens are extensively phosphorylated in Ad12-infected mammalian cells but are not phosphorylated in E. coli. Inasmuch as posttranslational phosphorylation at specific amino acid sites may be important for biological activity, we have studied the phosphorylation of the E. coli-produced T antigens in vitro by using a kinase activity isolated from cultured human KB cells. The kinase was purified about 300-fold and appears to be a cyclic AMP-independent, Ca2+-independent protein kinase requiring only ATP and Mg2+ for activity. To determine which amino acids are phosphorylated and whether phosphorylation in vitro occurs at the same amino acid sites that are phosphorylated in vivo, the Ad12 E1A T-antigen species synthesized by infected cells were metabolically labeled with 32Pi and compared with the E. coli-produced E1A T antigens labeled in vitro with [gamma-32P]ATP by using the partially purified kinase. Partial V8 proteolysis analysis gave similar patterns for in vivo- and in vitro-phosphorylated T antigen. Two-dimensional maps of tryptic phosphopeptides and of chymotryptic phosphopeptides suggested that mainly the same amino acid sites are phosphorylated in vitro and in vivo and that phosphorylation occurred at multiple sites distributed throughout the T-antigen molecule. Serine was the only amino acid that was phosphorylated both in vivo and in vitro, and, surprisingly, most serines appeared to be phosphorylated. The feasibility of faithfully phosphorylating T antigens in vitro suggests that the E. coli-produced Ad12 E1A 235R and 266R T antigens

  17. Effects of Introgression and Recombination on Haplotype Structure and Linkage Disequilibrium Surrounding a Locus Encoding Bymovirus Resistance in Barley

    PubMed Central

    Stracke, Silke; Presterl, Thomas; Stein, Nils; Perovic, Dragan; Ordon, Frank; Graner, Andreas

    2007-01-01

    We present a detailed analysis of linkage disequilibrium (LD) in the physical and genetic context of the barley gene Hv-eIF4E, which confers resistance to the barley yellow mosaic virus (BYMV) complex. Eighty-three SNPs distributed over 132 kb of Hv-eIF4E and six additional fragments genetically mapped to its flanking region were used to derive haplotypes from 131 accessions. Three haplogroups were recognized, discriminating between the alleles rym4 and rym5, which each encode for a spectrum of resistance to BYMV. With increasing map distance, haplotypes of susceptible genotypes displayed diverse patterns driven mainly by recombination, whereas haplotype diversity within the subgroups of resistant genotypes was limited. We conclude that the breakdown of LD within 1 cM of the resistance gene was generated mainly by susceptible genotypes. Despite the LD decay, a significant association between haplotype and resistance to BYMV was detected up to a distance of 5.5 cM from the resistance gene. The LD pattern and the haplotype structure of the target chromosomal region are the result of interplay between low recombination and recent breeding history. PMID:17151251

  18. Cloning of a cDNA encoding a surface antigen of Schistosoma mansoni schistosomula recognized by sera of vassinated mice

    SciTech Connect

    Dalton, J.P.; Tom, T.D.; Strand, M.

    1987-06-01

    Spleen cells of mice vaccinated with radiation-attenuated Schistosoma mansoni cercariae were used to produce monoclonal antibodies directed against newly transformed schistosomular surface antigens. One of these monoclonal antibodies recognized a polypeptide of 18 kDa. Binding was measured by radioimmunoassay. This glycoprotein was purified by monoclonal antibody immunoaffinity chromatography and a polyclonal antiserum was prepared against it. Immunofluorescence assays showed that the polyclonal antiserum bound to the surface of newly transformed schistosomula and lung-stage organisms but not to the surface of liver-stage and adult worms. Using this polyclonal antiserum we isolated recombinant clones from an adult worm cDNA expression library constructed in lambdagt11. Clone 654.2 contained an insert of 0.52 kilobase and hybridized to a 1.2-kilobase mRNA species from adult worms. Most importantly, clone 654.2 produced a fusion protein of 125 kDa that was reactive with sera of vaccinated mice that are capable of transferring resistance. This result encourages future vaccination trials with the fusion protein.

  19. Tandem repeat recombinant proteins as potential antigens for the sero-diagnosis of Schistosoma mansoni infection.

    PubMed

    Kalenda, Yombo Dan Justin; Kato, Kentaro; Goto, Yasuyuki; Fujii, Yoshito; Hamano, Shinjiro

    2015-12-01

    The diagnosis of schistosome infection, followed by effective treatment and/or mass drug administration, is crucial to reduce the disease burden. Suitable diagnostic tests and field-applicable tools are required to sustain schistosomiasis control programs. We therefore assessed the potential of tandem repeat (TR) proteins for sero-diagnosis of Schistosoma mansoni infection using an experimental mouse model. TR genes in the genome of S. mansoni were searched in silico and 7 candidates, named SmTR1, 3, 8, 9, 10, 11 and 15, were selected. Total RNA was extracted from S. mansoni adult worms and eggs. Target TR genes were amplified, cloned, and the proteins were expressed in Escherichia coli competent cells. Female BALB/c mice were infected with 100 S. mansoni cercariae and sera were collected each week post-infection for 18 weeks. The levels of IgG antibodies to SmTR antigens were compared to those to soluble egg antigen (SEA) and to soluble worm antigen preparation (SWAP). Sera of infected mice reacted to all the antigens whereas those of naïve mice did not. IgG responses to SmTR1, 3, 9 and 10 were detected at the early stage of infection. Interestingly, antibodies reacting to SmTR3, 9, 10 and 15 dramatically decreased 4 weeks after treatment with praziquantel, while those against SEA and SWAP remained elevated. Our study suggests that TR proteins, especially SmTR10, may be suitable antigens for sero-diagnosis of infection by S. mansoni and are potential markers for monitoring and surveillance of schistosomiasis, including re-infection after treatment with praziquantel. PMID:26148816

  20. Antigenic Profiles of Recombinant Proteins from Mycobacterium avium subsp paratuberculosis in Sheep with Johne's Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods to improve the ELISA test to detect Mycobacterium avium subsp paratuberculosis have been explored over several years. Previously, selected recombinant proteins of M. avium subspecies paratuberculosis were found to be immunogenic in cattle with Johne’s disease. In the present study, antibo...

  1. Gene cloning and characterization of the protein encoded by the Neospora caninum bradyzoite-specific antigen gene BAG1.

    PubMed

    Kobayashi, T; Narabu, S; Yanai, Y; Hatano, Y; Ito, A; Imai, S; Ike, K

    2013-06-01

    Neospora caninum is an Apicomplexan parasite that causes repeated abortion and stillbirth in cattle. The aim of this study was to clone the gene encoding the N. caninum orthologue (NcBAG1) of the Toxoplasma gondii bradyzoite-specific protein TgBAG1 and characterize its expression pattern in the parasite. Isolation of the full-length 684-bp gene revealed that it shared 78.3% sequence similarity with TgBAG1. NcBAG1 encodes a predicted protein of 227 amino acids with 80.3% similarity to TgBAG1. A putative signal peptide sequence and an invariant GVL motif characteristic of small heat-shock proteins were identified in the predicted N. caninum amino acid sequence. We expressed the NcBAG1 gene as a recombinant glutathione S-transferase fusion protein (rNcBAG1) in Escherichia coli and used the purified 60 kDa protein to obtain a monoclonal antibody (Mab). rNcBAG1 reacted to Mabs specific for NcBAG1 and TgBAG1. No reaction between the NcBAG1 Mab and N. caninum tachyzoites was observed. Although the predicted molecular mass of NcBAG1 is 25 kDa, Western blot analysis of parasite lysates using the NcBAG1 Mab revealed a cross-reactive protein of approximately 30 kDa. Additionally, immunofluorescence assays using the tachyzoite-specific Mab for NcSAG1 and the bradyzoite-specific Mab for TgBAG1 or NcSAG4 revealed NcBAG1-specific expression in bradyzoites in cultures exposed to sodium nitroprusside, a reagent that increases the frequency of bradyzoites. Interestingly, the NcBAG1 protein was identified in the cytoplasm of the bradyzoite-stage parasites. This preliminary analysis of the NcBAG1 gene will assist investigations into the role of this protein in N. caninum . PMID:23245337

  2. Hierarchical Bayesian mixture modelling for antigen-specific T-cell subtyping in combinatorially encoded flow cytometry studies

    PubMed Central

    Lin, Lin; Chan, Cliburn; Hadrup, Sine R.; Froesig, Thomas M.; Wang, Quanli; West, Mike

    2014-01-01

    Novel uses of automated flow cytometry technology for measuring levels of protein markers on thousands to millions of cells are promoting increasing need for relevant, customized Bayesian mixture modelling approaches in many areas of biomedical research and application. In studies of immune profiling in many biological areas, traditional flow cytometry measures relative levels of abundance of marker proteins using fluorescently labeled tags that identify specific markers by a single-color. One specific and important recent development in this area is the use of combinatorial marker assays in which each marker is targeted with a probe that is labeled with two or more fluorescent tags. The use of several colors enables the identification of, in principle, combinatorially increasingly numbers of subtypes of cells, each identified by a subset of colors. This represents a major advance in the ability to characterize variation in immune responses involving larger numbers of functionally differentiated cell subtypes. We describe novel classes of Markov chain Monte Carlo methods for model fitting that exploit distributed GPU (graphics processing unit) implementation. We discuss issues of cellular subtype identification in this novel, general model framework, and provide a detailed example using simulated data. We then describe application to a data set from an experimental study of antigen-specific T-cell subtyping using combinatorially encoded assays in human blood samples. Summary comments discuss broader questions in applications in immunology, and aspects of statistical computation. PMID:23629459

  3. New Skin Test for Detection of Bovine Tuberculosis on the Basis of Antigen-Displaying Polyester Inclusions Produced by Recombinant Escherichia coli

    PubMed Central

    Chen, Shuxiong; Parlane, Natalie A.; Lee, Jason; Wedlock, D. Neil; Buddle, Bryce M.

    2014-01-01

    The tuberculin skin test for diagnosing tuberculosis (TB) in cattle lacks specificity if animals are sensitized to environmental mycobacteria, as some antigens in purified protein derivative (PPD) prepared from Mycobacterium bovis are present in nonpathogenic mycobacteria. Three immunodominant TB antigens, ESAT6, CFP10, and Rv3615c, are present in members of the pathogenic Mycobacterium tuberculosis complex but absent from the majority of environmental mycobacteria. These TB antigens have the potential to enhance skin test specificity. To increase their immunogenicity, these antigens were displayed on polyester beads by translationally fusing them to a polyhydroxyalkanoate (PHA) synthase which mediated formation of antigen-displaying inclusions in recombinant Escherichia coli. The most common form of these inclusions is poly(3-hydroxybutyric acid) (PHB). The respective fusion proteins displayed on these PHB inclusions (beads) were identified using tryptic peptide fingerprinting analysis in combination with matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). The surface exposure and accessibility of antigens were assessed by enzyme-linked immunosorbent assay (ELISA). Polyester beads displaying all three TB antigens showed greater reactivity with TB antigen-specific antibody than did beads displaying only one TB antigen. This was neither due to cross-reactivity of antibodies with the other two antigens nor due to differences in protein expression levels between beads displaying single or three TB antigens. The triple-antigen-displaying polyester beads were used for skin testing of cattle and detected all cattle experimentally infected with M. bovis with no false-positive reactions observed in those sensitized to environmental mycobacteria. The results suggested applicability of TB antigen-displaying polyester inclusions as diagnostic reagents for distinguishing TB-infected from noninfected animals. PMID:24532066

  4. Recombinant Lactococcus lactis can make the difference in antigen-specific immune tolerance induction, the Type 1 Diabetes case

    PubMed Central

    2014-01-01

    Especially in western civilizations, immune diseases that are driven by innocuous (auto- or allo-) antigens are gradually evolving to become pandemic threats. A particularly poignant example is type 1 diabetes, where young children are confronted with the perspective and consequences of total pancreatic β-cell destruction. Along these disquieting observations we find ourselves equipped with impressively accumulating molecular immunological knowledge on the ins and outs of these pathologies. Often, however, it is difficult to translate this wealth into efficacious medicines. The molecular understanding, the concept of oral tolerance induction, the benefit of using recombinant Lactococcus lactis therein and recent openings towards their clinical use may well enable turning all colors to their appropriate fields on this Rubik's cube. PMID:25185797

  5. Cellular and humoral immune responses to recombinant Smp17.7 Schistosoma mansoni antigen.

    PubMed

    Al-Sherbiny, Maged M; Galal, Iman F; Karim, Amr M; Ashour, Ameen A; Saad, Abdel-Hakim M

    2003-12-01

    To determine the immunological responses to S. mansoni antigen rSmp17.7, a total of 184 subjects, 174 patients from a schistosomiasis endemic area, and 10 controls were used. Proliferation, cytokine profile in culture supernatants from antigen-stimulated peripheral blood mononuclear cells and specific IgG1, IgG3, IgG4, IgA, IgM & IgE levels were assessed. The highest stimulation index to rSmp17.7 was detected in S. mansoni patients. The evaluation of the cytokine profile [IL-2, IL-4 & IFN-gamma] in response to this antigen showed a significant increase as demonstrated by ELISA. Specifically, IFN-gamma and IL-2 were significantly detected by flow cytometry. IgG1 and IgM were the only Igs which showed a significant increase. These results highlight the importance of rSmp17.7 as a candidate vaccine for schistosomiasis. The results pave the way to understand the mechanism of schistosome-vaccine efficacy. PMID:14708863

  6. A functional recombinant single-chain T cell receptor fragment capable of selectively targeting antigen-presenting cells.

    PubMed

    Epel, Malka; Ellenhorn, Joshua D; Diamond, Don J; Reiter, Yoram

    2002-11-01

    Specificity in the immune system is dictated and regulated by specific recognition of peptide/major histocompatibility complexes (MHC) by the T cell receptor (TCR). Such peptide/MHC complexes are a desirable target for novel approaches in immunotherapy because of their highly restricted fine specificity. Recently a potent anti-human p53 CD8(+) cytotoxic T lymphocyte (CTL) response has been developed in HLA-A2 transgenic mice after immunization with peptides corresponding to HLA-A2 motifs from human p53. An alpha/beta T-cell receptor was cloned from such CTL which exhibited a moderately high affinity to the human p53(149-157) peptide. In this report, we investigated the possibility of using a recombinant tumor-specific TCR for antigen-specific elimination of cells that express the specific MHC-peptide complex. To this end, we constructed a functional single-chain Fv fragment from the cloned TCR and fused it to a very potent cytotoxic molecule, a truncated form of Pseudomonas exotoxin A (PE38). The p53 TCR scFv-P38 fusion protein was generated by in vitro refolding from bacterially-expressed inclusion bodies, and was found to be functional by its ability to bind antigen-presenting cells (APC) which express the specific p53-derived peptide. Moreover, we have shown that the p53-specific TCR scFv-PE38 molecule specifically kills APC in a peptide-dependent manner. These results represent the first time that a TCR-derived recombinant single-chain Fv fragment has been used as a targeting moiety to deliver a cytotoxic effector molecule to cells and has been able to mediate the efficient killing of the particular cell population that expresses the specific MHC/peptide complex. Similarly to antibody-based targeting approaches, TCR with tumor cell specificity represent attractive candidates for generating new, very specific targeting moieties for various modes of cancer immunotherapy. PMID:12384808

  7. Neutralizing antibodies respond to a bivalent dengue DNA vaccine or/and a recombinant bivalent antigen.

    PubMed

    Zhang, Zhi-Shan; Weng, Yu-Wei; Huang, Hai-Long; Zhang, Jian-Ming; Yan, Yan-Sheng

    2015-02-01

    There is currently no effective vaccine to prevent dengue infection, despite the existence of multiple studies on potential methods of immunization. The aim of the present study was to explore the effect of DNA and/or recombinant protein on levels of neutralizing antibodies. For this purpose, envelope domain IIIs of dengue serotypes 1 and 2 (DEN-1/2)were spliced by a linker (Gly‑Gly‑Ser‑Gly‑Ser)3 and cloned into the prokaryotic expression plasmid pET30a (+) and eukaryotic vector pcDNA3.1 (+). The chimeric bivalent protein was expressed in Escherichia coli, and one‑step purification by high‑performance liquid chromatography was conducted. Protein expression levels of the DNA plasmid were tested in BHK‑21 cells by indirect immunofluorescent assay. In order to explore a more effective immunization strategy and to develop neutralizing antibodies against the two serotypes, mice were inoculated with recombinant bivalent protein, the DNA vaccine, or the two given simultaneously. Presence of the specific antibodies was tested by ELISA and the presence of the neutralizing antibodies was determined by plaque reduction neutralization test. Results of the analysis indicated that the use of a combination of DNA and protein induced significantly higher titers of neutralizing antibodies against either DEN‑1 or DEN‑2 (1:64.0 and 1:76.1, respectively) compared with the DNA (1:24.7 and 1:26.9, DEN‑1 and DEN‑2, respectively) or the recombinant protein (1:34.9 and 1:45.3 in DEN‑1 and DEN‑2, respectively). The present study demonstrated that the combination of recombinant protein and DNA as an immunization strategy may be an effective method for the development of a vaccine to prevent dengue virus infection. PMID:25371092

  8. Epitope-based recombinant diagnostic antigen to distinguish natural infection from vaccination with hepatitis A virus vaccines.

    PubMed

    Su, Qiudong; Guo, Minzhuo; Jia, Zhiyuan; Qiu, Feng; Lu, Xuexin; Gao, Yan; Meng, Qingling; Tian, Ruiguang; Bi, Shengli; Yi, Yao

    2016-07-01

    Hepatitis A virus (HAV) infection can stimulate the production of antibodies to structural and non-structural proteins of the virus. However, vaccination with an inactivated or attenuated HAV vaccine produces antibodies mainly against structural proteins, whereas no or very limited antibodies are produced against the non-structural proteins. Current diagnostic assays to determine exposure to HAV, such as the Abbott HAV AB test, detect antibodies only to the structural proteins and so are not able to distinguish a natural infection from vaccination with an inactivated or attenuated virus. Here, we constructed a recombinant tandem multi-epitope diagnostic antigen (designated 'H1') based on the immune-dominant epitopes of the non-structural proteins of HAV to distinguish the two situations. H1 protein expressed in Escherichia coli and purified by affinity and anion exchange chromatography was applied in a double-antigen sandwich ELISA for the detection of anti-non-structural HAV proteins, which was confirmed to distinguish a natural infection from vaccination with an inactivated or attenuated HAV vaccine. PMID:26994964

  9. Regeneration of Recombinant Antigen Microarrays for the Automated Monitoring of Antibodies against Zoonotic Pathogens in Swine Sera

    PubMed Central

    Meyer, Verena K.; Kober, Catharina; Niessner, Reinhard; Seidel, Michael

    2015-01-01

    The ability to regenerate immobilized proteins like recombinant antigens (rAgs) on surfaces is an unsolved problem for flow-based immunoassays on microarray analysis systems. The regeneration on microarray chip surfaces is achieved by changing the protein structures and desorption of antibodies. Afterwards, reactivation of immobilized protein antigens is necessary for reconstitution processes. Any backfolding should be managed in a way that antibodies are able to detect the protein antigens in the next measurement cycle. The regeneration of rAg microarrays was examined for the first time on the MCR3 flow-based chemiluminescence (CL) microarray analysis platform. The aim was to reuse rAg microarray chips in order to reduce the screening effort and costs. An antibody capturing format was used to detect antibodies against zoonotic pathogens in sera of slaughtered pigs. Different denaturation and reactivation buffers were tested. Acidic glycine-SDS buffer (pH 2.5) and 8 M guanidinium hydrochloride showed the best results in respect of denaturation efficiencies. The highest CL signals after regeneration were achieved with a carbonate buffer containing 10 mM DTT and 0.1% BSA for reactivation. Antibodies against Yersinia spp. and hepatitis E virus (HEV) were detected in swine sera on one immunochip over 4 days and 25 measurement cycles. Each cycle took 10 min for detection and regeneration. By using the rAg microarray chip, a fast and automated screening of antibodies against pathogens in sera of slaughtered pigs would be possible for zoonosis monitoring. PMID:25625908

  10. 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. PMID:23283638