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Sample records for 51-kilodalton antigen gene

  1. Analysis of 16S rRNA and 51-kilodalton antigen gene and transmission in mice of Ehrlichia risticii in virgulate trematodes from Elimia livescens snails in Ohio.

    PubMed

    Kanter, M; Mott, J; Ohashi, N; Fried, B; Reed, S; Lin, Y C; Rikihisa, Y

    2000-09-01

    Operculate snails (the family Pleuroceridae: Elimia livescens) were collected between June and October 1998 from a river in central Ohio where repeated cases of Potomac horse fever (PHF) have occurred. Of collected snails, consistently 50 to 80% carried a combination of cercariae and sporocysts of digenetic virgulate trematodes. The trematodes obtained from each snail were pooled and tested for Ehrlichia risticii, the agent of PHF, by nested PCR using primers specific to the 16S rRNA gene. Out of a total of 209 trematode pools, 50 pools were found to be positive by PCR. The DNA sequence of the 16S rRNA gene identified in one trematode pool was identical to that of the type strain of E. risticii, and the sequence of the gene identified in another pool differed from that of the type strain by 1 nucleotide. Comparison of the deduced amino acid sequence of the partial 51-kDa antigen gene from various sources revealed that Maryland, Ohio (except Ohio 081), and Kentucky strains are in a cluster distinct from the sequences obtained from sources in California and Oregon. Ohio 081 was shown previously by antigenic composition analysis to be distinct from other groups. However, all sequences examined were not segregated according to their sources: horse blood or infected trematodes. E. risticii was found to be transmittable from trematodes to mice and was subsequently passaged from infected mice to additional mice, as determined by PCR analysis. Our findings suggest the evolution of E. risticii in the natural reservoir in separate geographic regions and persistent infection of trematode populations with E. risticii during summer and early fall. The study also suggests that the mouse can be used to isolate E. risticii from the infected trematode. PMID:10970382

  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. Candidate vaccine antigens and genes in Pasteurella multocida.

    PubMed

    Adler, B; Bulach, D; Chung, J; Doughty, S; Hunt, M; Rajakumar, K; Serrano, M; van Zanden, A; Zhang, Y; Ruffolo, C

    1999-08-20

    Pasteurella multocida is the causative agent of fowl cholera and other diseases of production animals. Isolates are classified into five groups based on capsular antigens and into 16 serotypes based on LPS antigens. Strains causing fowl cholera are most frequently designated A:1, A:3 or A:4. Whole cell bacterins can provide some degree of protection, but only against the homologous LPS serotype. There is good evidence that cross-protective antigens are expressed only under in vivo conditions. Empirically derived, live, attenuated vaccines can protect against heterologous serotypes, but because the basis for attenuation is undefined, reversion to virulence is not uncommon. Work in our laboratory is aimed at using a variety of approaches to identify potential protective antigens or virulence genes to be used as candidates for attenuating mutations or as the basis for vaccine antigen delivery systems. The gene encoding an outer membrane protein, Oma87, which is a homologue of the D15 protective antigen of Haemophilus influenzae, was cloned and sequenced. Rabbit antiserum prepared against recombinant Oma87 could passively protect mice against infection. Type 4 fimbriae form the basis of vaccines against ovine footrot and bovine keratoconjunctivitis. We have identified type 4 fimbriae on the surface of P. multocida, purified the fimbrial subunit protein, PtfA, and determined its N-terminal amino acid sequence. Subsequent cloning of the ptfA gene and its inactivation will now be used to assess the importance of type 4 fimbriae in virulence. There has long been anecdotal evidence for the importance of capsule in virulence, but unequivocal genetic evidence for such a role is lacking. We have cloned and characterised the capsule biosynthetic locus in P. multocida A:1 and identified four bex genes involved in capsule transport and genes encoding enzymes involved in the biosynthesis and transfer of the N-acetyl glucosamine and glucuronic acid components of the capsule. It has

  4. 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 ...

  5. 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

  6. Comparison of O-Antigen Gene Clusters of Escherichia coli (Shigella) Sonnei and Plesiomonas shigelloides O17: Sonnei Gained Its Current Plasmid-Borne O-Antigen Genes from P. shigelloides in a Recent Event

    PubMed Central

    Shepherd, James G.; Wang, Lei; Reeves, Peter R.

    2000-01-01

    Escherichia coli Sonnei has an O antigen identical to that of Plesiomonas shigelloides O17, and its O-antigen gene cluster is located on a plasmid. By sequencing the chromosomal O-antigen gene cluster of P. shigelloides O17 and comparing it with that of Sonnei, we showed that Sonnei gained its O-antigen genes recently. PMID:10992522

  7. Human platelet antigen gene frequencies in the Austrian population.

    PubMed

    Holensteiner, A; Walchshofer, S; Adler, A; Kittl, E M; Mayr, W R; Panzer, S

    1995-01-01

    Gene frequencies for the human platelet antigen systems HPA-1, -2, -3, and -5 were determined directly from DNA isolated from cord blood of more than 900 randomly selected Caucasoid newborns in Vienna, Austria. Genotyping was performed by specific amplification of the respective regions coding for platelet glycoproteins GP Ib, IIb, IIIa, and Ia by PCR. These PCR products were analyzed after restriction enzyme digestion and electrophoresis. The observed gene frequencies were: HPA-1a: 0.852, HPA-1b: 0.148; HPA-2a: 0.918, HPA-2b: 0.082; HPA-3a: 0.612, HPA-3b: 0.388; HPA-5a: 0.892, HPA-5b: 0.108. There was a good fit with the Hardy-Weinberg equilibrium. Results from serological determinations and genotyping showed no discrepancies. PMID:7607581

  8. 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

  9. Evidence for horizontal gene transfer of two antigenically distinct O antigens in Bordetella bronchiseptica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antigenic variation is one mechanism pathogens use to avoid immune-mediated competition between closely related strains. Here, we show that two Bordetella bronchiseptica strains, RB50 and 1289, express two antigenically distinct O-antigen serotypes (O1 and O2 respectively). When 18 additional B. b...

  10. Cell-type specific regulation of gene expression by simian virus 40 T antigens

    SciTech Connect

    Cantalupo, Paul G.; Saenz-Robles, Maria Teresa; Rathi, Abhilasha V.; Beerman, Rebecca W.; Patterson, William H.; Whitehead, Robert H.; Pipas, James M.

    2009-03-30

    SV40 transforms cells through the action of two oncoproteins, large T antigen and small t antigen. Small t antigen targets phosphatase PP2A, while large T antigen stimulates cell proliferation and survival by action on multiple proteins, including the tumor suppressors Rb and p53. Large T antigen also binds components of the transcription initiation complex and several transcription factors. We examined global gene expression in SV40-transformed mouse embryo fibroblasts, and in enterocytes obtained from transgenic mice. SV40 transformation alters the expression of approximately 800 cellular genes in both systems. Much of this regulation is observed in both MEFs and enterocytes and is consistent with T antigen action on the Rb-E2F pathway. However, the regulation of many genes is cell-type specific, suggesting that unique signaling pathways are activated in different cell types upon transformation, and that the consequences of SV40 transformation depends on the type of cell targeted.

  11. T-cell intracellular antigens function as tumor suppressor genes

    PubMed Central

    Sánchez-Jiménez, C; Ludeña, M D; Izquierdo, J M

    2015-01-01

    Knockdown of T-cell intracellular antigens TIA1 and TIAR in transformed cells triggers cell proliferation and tumor growth. Using a tetracycline-inducible system, we report here that an increased expression of TIA1 or TIAR in 293 cells results in reduced rates of cell proliferation. Ectopic expression of these proteins abolish endogenous TIA1 and TIAR levels via the regulation of splicing of their pre-mRNAs, and partially represses global translation in a phospho-eukaryotic initiation factor 2 alpha-dependent manner. This is accompanied by cell cycle arrest at G1/S and cell death through caspase-dependent apoptosis and autophagy. Genome-wide profiling illustrates a selective upregulation of p53 signaling pathway-related genes. Nude mice injected with doxycycline-inducible cells expressing TIA1 or TIAR retard, or even inhibit, growth of xenotumors. Remarkably, low expressions of TIA1 and TIAR correlate with poor prognosis in patients with lung squamous cell carcinoma. These findings strongly support the concept that TIA proteins act as tumor suppressor genes. PMID:25741594

  12. Immunophenotypic and antigen receptor gene rearrangement analysis in T cell neoplasia.

    PubMed Central

    Knowles, D. M.

    1989-01-01

    The author reviews the immunophenotypic profiles displayed by the major clinicopathologic categories of T cell neoplasia, the immunophenotypic criteria useful in the immunodiagnosis of T cell neoplasia, and the contributions made by antigen receptor gene rearrangement analysis to the understanding of T cell neoplasia. Neoplasms belonging to distinct clinicopathologic categories of T cell neoplasia often exhibit characteristic immunophenotypic profiles. Approximately 80% of lymphoblastic lymphomas and 20% of acute lymphoblastic leukemias express phenotypes consistent with prethymic and intrathymic stages of T cell differentiation, including intranuclear terminal deoxynucleotidyl transferase. Cutaneous T cell lymphomas of mycosis fungoides type usually express pan-T cell antigens CD2, CD5, and CD3, often lack the pan-T cell antigen CD7, and usually express the mature, peripheral helper subset phenotype, CD4+ CD8-. Cutaneous T cell lymphomas of nonmycosis fungoides type and peripheral T cell lymphomas often lack one or more pan-T cell antigens and, in addition, occasionally express the anomalous CD4+ CD8+ or CD4- CD8- phenotypes. T gamma-lymphoproliferative disease is divisable into two broad categories: those cases that are CD3 antigen positive and exhibit clonal T cell receptor beta chain (TCR-beta) gene rearrangements and those cases that are CD3 antigen negative and exhibit the TCR-beta gene germline configuration. Human T cell lymphotropic virus-I (HTLV-I) associated Japanese, Carribean, and sporadic adult T cell leukemia/lymphomas usually express pan-T cell antigens, the CD4+ CD8- phenotype, and various T cell-associated activation antigens, including the interleukin-2 receptor (CD25). Immunophenotypic criteria useful in the immunodiagnosis of T cell neoplasia include, in increasing order of utility, T cell predominance, T cell subset antigen restriction, anomalous T cell subset antigen expression, and deletion of one or more pan-T cell antigens. Only in

  13. Molecular characterization of swine leukocyte antigen (SLA) class II genes in outbred pig populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The highly polymorphic swine leukocyte antigen (SLA) genes are one of the most important determinants in swine immune, disease and vaccine responses. Thus, understanding how SLA gene polymorphism affects immunity, especially in outbred pig populations with a diverse genetic background, requires accu...

  14. Phylogenetic analysis of the swine leukocyte antigen - 2 gene for Korean native pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to investigate genetic distances of the SLA-2 gene, to characterize SLA-2 alleles, and to provide basic genetic information of Korean pigs. The swine leukocyte antigen - 2 (SLA-2) gene in the MHC classical region was cloned with spleen tissues from Korean native pigs ...

  15. Improved efficiency in amplification of Escherichia coli o-antigen gene clusters using genome-wide sequence comparison

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: In many bacteria including E. coli, genes encoding O-antigens are clustered in the chromosome, with a 39-bp JUMPstart sequence and gnd gene located upstream and downstream of the cluster, respectively. For determining the DNA sequence of the E. coli O-antigen gene cluster, one set of P...

  16. Cellular gene expression induced by parasite antigens and allergens in neonates from parasite-infected mothers.

    PubMed

    Soboslay, Peter T; Orlikowsky, Thorsten; Huang, Xiangsheng; Gille, Christian; Spring, Bärbel; Kocherscheidt, Lars; Agossou, Abram; Banla, Meba; Bonin, Michael; Köhler, Carsten

    2016-05-01

    Prenatal exposure to parasite antigens or allergens will influence the profile and strength of postnatal immune responses, such contact may tolerize and increase susceptibility to future infections or sensitize to environmental allergens. Exposure in utero to parasite antigens will distinctly alter cellular gene expression in newborns. Gene microarrays were applied to study gene expression in umbilical cord blood cell (UCBC) from parasite-exposed (Para-POS) and non-exposed (Para-NEG) neonates. UCBC were activated with antigens of helminth (Onchocerca volvulus), amoeba (Entamoeba histolytica) or allergens of mite (Dermatophagoides farinae). When UCBC from Para-POS and Para-NEG newborns were exposed to helminth antigens or allergens consistent differences occurred in the expression of genes encoding for MHC class I and II alleles, signal transducers of activation and transcription (STATs), cytokines, chemokines, immunoglobulin heavy and light chains, and molecules associated with immune regulation (SOCS, TLR, TGF), inflammation (TNF, CCR) and apoptosis (CASP). Expression of genes associated with innate immune responses were enhanced in Para-NEG, while in Para-POS, the expression of MHC class II and STAT genes was reduced. Within functional gene networks for cellular growth, proliferation and immune responses, Para-NEG neonates presented with significantly higher expression values than Para-POS. In Para-NEG newborns, the gene cluster and pathway analyses suggested that gene expression profiles may predispose for the development of immunological, hematological and dermatological disorders upon postnatal helminth parasite infection or allergen exposure. Thus, prenatal parasite contact will sensitize without generating aberrant inflammatory immune responses, and increased pro-inflammatory but decreased regulatory gene expression profiles will be present in those neonates lacking prenatal parasite antigen encounter. PMID:27062712

  17. Molecular characteristics of an immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyophthirius multifiliis, a ciliated protozoan parasite of fish, expresses surface antigens (i-antigens), which react with host antibodies that render them immobile. The nucleotide sequence of an i-antigen gene of Ichthyophthirius multifiliis strain ARS-6 was deduced. The predicted protein of 47...

  18. 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

  19. 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

  20. Structure and gene cluster of the O-antigen of Escherichia coli O133.

    PubMed

    Shashkov, Alexander S; Zhang, Yuanyuan; Sun, Qiangzheng; Guo, Xi; Senchenkova, Sof'ya N; Perepelov, Andrei V; Knirel, Yuriy A

    2016-07-22

    The O-specific polysaccharide (O-antigen) of Escherichia coli O133 was obtained by mild acid hydrolysis of the lipopolysaccharide of E. coli O133. The structure of the hexasaccharide repeating unit of the polysaccharide was elucidated by (1)H and (13)C NMR spectroscopy, including a two-dimensional (1)H-(1)H ROESY experiment: Functions of genes in the O-antigen gene cluster were putatively identified by comparison with sequences in the available databases and, particularly, an encoded predicted multifunctional glycosyltransferase was assigned to three α-l-rhamnosidic linkages. PMID:27203746

  1. Characterization of am404, an amber mutation in the simian virus 40 T antigen gene.

    PubMed Central

    Rawlins, D R; Collis, P; Muzyczka, N

    1983-01-01

    We analyzed the biological activity of an amber mutation, am404, at map position 0.27 in the T antigen gene of simian virus 40. Immunoprecipitation of extracts from am404-infected cells demonstrated the presence of an amber protein fragment (am T antigen) of the expected molecular weight (67,000). Differential immunoprecipitation with monoclonal antibody demonstrated that am T antigen was missing the carboxy-terminal antigenic determinants. The amber mutant was shown to be defective for most of the functions associated with wild-type T antigen. The mutant did not replicate autonomously, but this defect could be complemented by a helper virus (D. R. Rawlins and N. Muzyczka, J. Virol. 36:611-616, 1980). The mutant failed to transform nonpermissive rodent cells and did not relieve the host range restriction of adenovirus 2 in monkey cells. However, stimulation of host cell DNA, whose functional region domain has been mapped within that portion of the protein synthesized by the mutant, could be demonstrated in am404-infected cells. A number of unexpected observations were made. First, the am T antigen was produced in unusually large amounts in a simian virus 40-transformed monkey cell line (COS-1), but overproduction was not seen in nontransformed monkey cells regardless of whether or not a helper virus was present. This feature of the mutant was presumably the result of the inability of am T antigen to autoregulate, the level of wild-type T antigen in COS-1 cells, and the unusually short half-life of am T antigen in vivo. Pulse-chase experiments indicated that am T antigen had an intracellular half-life of approximately 10 min. In addition, although the am T antigen retained the major phosphorylation site found in simian virus 40 T antigen, it was not phosphorylated. Thus, phosphorylation of simian virus 40 T antigen is not required for the stimulation of host cell DNA synthesis. Finally, fusion of am404-infected monkey cells with Escherichia coli protoplasts

  2. Hypervariable antigen genes in malaria have ancient roots

    PubMed Central

    2013-01-01

    Background The var genes of the human malaria parasite Plasmodium falciparum are highly polymorphic loci coding for the erythrocyte membrane proteins 1 (PfEMP1), which are responsible for the cytoaherence of P. falciparum infected red blood cells to the human vasculature. Cytoadhesion, coupled with differential expression of var genes, contributes to virulence and allows the parasite to establish chronic infections by evading detection from the host’s immune system. Although studying genetic diversity is a major focus of recent work on the var genes, little is known about the gene family's origin and evolutionary history. Results Using a novel hidden Markov model-based approach and var sequences assembled from additional isolates and species, we are able to reveal elements of both the early evolution of the var genes as well as recent diversifying events. We compare sequences of the var gene DBLα domains from divergent isolates of P. falciparum (3D7 and HB3), and a closely-related species, Plasmodium reichenowi. We find that the gene family is equally large in P. reichenowi and P. falciparum -- with a minimum of 51 var genes in the P. reichenowi genome (compared to 61 in 3D7 and a minimum of 48 in HB3). In addition, we are able to define large, continuous blocks of homologous sequence among P. falciparum and P. reichenowi var gene DBLα domains. These results reveal that the contemporary structure of the var gene family was present before the divergence of P. falciparum and P. reichenowi, estimated to be between 2.5 to 6 million years ago. We also reveal that recombination has played an important and traceable role in both the establishment, and the maintenance, of diversity in the sequences. Conclusions Despite the remarkable diversity and rapid evolution found in these loci within and among P. falciparum populations, the basic structure of these domains and the gene family is surprisingly old and stable. Revealing a common structure as well as conserved

  3. Antigen uptake and expression of antigen presentation-related immune genes in flounder (Paralichthys olivaceus) after vaccination with an inactivated Edwardsiella tarda immersion vaccine, following hyperosmotic treatment.

    PubMed

    Gao, Yingli; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2016-08-01

    Antigen uptake is a critical process for activation of the immune system, and therefore the ability to enhance antigen uptake is a primary consideration in the development of an immersion vaccination of fish. In the present work, flounders (Paralichthys olivaceus) were immersed in three hyperosmotic solutions with 40, 50 and 60‰ salinities, then transferred into seawater of normal salinity (i.e. 30‰) containing formalin-inactivated Edwardsiella tarda for 30 min. The antigen uptake in vaccinated flounder was determined using an absolute quantitative PCR (qPCR). The results showed significantly higher antigen uptake in the tissues of flounders immersed in solutions with 50‰ and 60‰ salinity compared to the control group directly immersed in vaccine (DI) (P < 0.05), and the highest amount of antigen was detected in flounders immersed in the 50‰ salinity solution, whereas there was no significant difference in antigen uptake between the 40‰ salinity group and the DI group (P > 0.05). A rapid and significant increase in antigen uptake was detected in the mucosal-associated tissues including the gill, skin and intestine (P < 0.05) compared with the spleen, kidney and liver. Antigen uptake in the gill and skin both peaked at 30 min post immersion, which was significantly higher than the levels of uptake measured in the other tissues (P < 0.05), and then quickly declined. In contrast, antigen uptake in the spleen, kidney and liver gradually increased 3 h post immersion (hpi). The expression profiles of four antigen presentation-related immune genes (MHC Iα, MHC IIα, CD4-1 and CD8α) were investigated after immersion. These four genes showed a significantly stronger response in the immersed flounders exposed to 50‰ salinity compared with the DI group (P < 0.05). In the mucosal-associated tissues, the expression of MHC Iα and CD8α genes peaked at 24 hpi, while the expression of MHC IIα and CD4-1 genes showed up-regulation in the gill and skin

  4. An evolutionarily mobile antigen receptor variable region gene: Doubly rearranging NAR-TcR genes in sharks

    PubMed Central

    Criscitiello, Michael F.; Saltis, Mark; Flajnik, Martin F.

    2006-01-01

    Distinctive Ig and T cell receptor (TcR) chains define the two major lineages of vertebrate lymphocyte yet similarly recognize antigen with a single, membrane-distal variable (V) domain. Here we describe the first antigen receptor chain that employs two V domains, which are generated by separate VDJ gene rearrangement events. These molecules have specialized “supportive” TcRδV domains membrane-proximal to domains with most similarity to IgNAR V. The ancestral NAR V gene encoding this domain is hypothesized to have recombined with the TRD locus in a cartilaginous fish ancestor >200 million years ago and encodes the first V domain shown to be used in both Igs and TcRs. Furthermore, these data support the view that γ/δ TcRs have for long used structural conformations recognizing free antigen. PMID:16549799

  5. Structure and gene cluster of the O-antigen of Escherichia coli O137.

    PubMed

    Perepelov, Andrei V; Guo, Xi; Senchenkova, Sof'ya N; Li, Yayue; Shashkov, Alexander S; Liu, Bin; Knirel, Yuriy A

    2016-03-01

    The O-polysaccharide (O-antigen) was isolated from the lipopolysaccharide of Escherichia coli O137 and studied by sugar analysis and NMR spectroscopy. The following structure of the branched tetrasaccharide repeating unit was established: Formula: see text] Both structure and gene cluster of the E. coli O137 polysaccharide are related to those of the E. coli K40 polysaccharide (Amor et al., 1999), which lacks the side-chain glucosylation but contains serine that is amide-linked to GlcA. Functions of genes in the O137-antigen gene cluster were assigned by a comparison with those in K40 and sequences in the available databases. Particularly, predicted glycosyltransferases encoded in the gene cluster were assigned to the formation of three glycosidic linkages in the O-polysaccharide repeating unit. PMID:26845703

  6. Evolutionary origin and human-specific expansion of a cancer/testis antigen gene family.

    PubMed

    Zhang, Qu; Su, Bing

    2014-09-01

    Cancer/testis (CT) antigens are encoded by germline genes and are aberrantly expressed in a number of human cancers. Interestingly, CT antigens are frequently involved in gene families that are highly expressed in germ cells. Here, we presented an evolutionary analysis of the CTAGE (cutaneous T-cell-lymphoma-associated antigen) gene family to delineate its molecular history and functional significance during primate evolution. Comparisons among human, chimpanzee, gorilla, orangutan, macaque, marmoset, and other mammals show a rapid and primate specific expansion of CTAGE family, which starts with an ancestral retroposition in the haplorhini ancestor. Subsequent DNA-based duplications lead to the prosperity of single-exon CTAGE copies in catarrhines, especially in humans. Positive selection was identified on the single-exon copies in comparison with functional constraint on the multiexon copies. Further sequence analysis suggests that the newly derived CTAGE genes may obtain regulatory elements from long terminal repeats. Our result indicates the dynamic evolution of primate genomes, and the recent expansion of this CT antigen family in humans may confer advantageous phenotypic traits during early human evolution. PMID:24916032

  7. MOLECULAR CHARACTERIZATION OF SWINE LEUKOCYTE ANTIGEN (SLA) CLASS I GENES IN OUTBRED PIG POPULATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The highly polymorphic swine leukocyte antigen (SLA) genes are one of the most important determinants in swine immune responses to infectious diseases, vaccines, and in transplantation. Study of SLA influence requires accurate and effective typing methods. We developed a simple and rapid method to t...

  8. Alternative haplotypes of antigen processing genes in zebrafish diverged early in vertebrate evolution.

    PubMed

    McConnell, Sean C; Hernandez, Kyle M; Wcisel, Dustin J; Kettleborough, Ross N; Stemple, Derek L; Yoder, Jeffrey A; Andrade, Jorge; de Jong, Jill L O

    2016-08-23

    Antigen processing and presentation genes found within the MHC are among the most highly polymorphic genes of vertebrate genomes, providing populations with diverse immune responses to a wide array of pathogens. Here, we describe transcriptome, exome, and whole-genome sequencing of clonal zebrafish, uncovering the most extensive diversity within the antigen processing and presentation genes of any species yet examined. Our CG2 clonal zebrafish assembly provides genomic context within a remarkably divergent haplotype of the core MHC region on chromosome 19 for six expressed genes not found in the zebrafish reference genome: mhc1uga, proteasome-β 9b (psmb9b), psmb8f, and previously unknown genes psmb13b, tap2d, and tap2e We identify ancient lineages for Psmb13 within a proteasome branch previously thought to be monomorphic and provide evidence of substantial lineage diversity within each of three major trifurcations of catalytic-type proteasome subunits in vertebrates: Psmb5/Psmb8/Psmb11, Psmb6/Psmb9/Psmb12, and Psmb7/Psmb10/Psmb13. Strikingly, nearby tap2 and MHC class I genes also retain ancient sequence lineages, indicating that alternative lineages may have been preserved throughout the entire MHC pathway since early diversification of the adaptive immune system ∼500 Mya. Furthermore, polymorphisms within the three MHC pathway steps (antigen cleavage, transport, and presentation) are each predicted to alter peptide specificity. Lastly, comparative analysis shows that antigen processing gene diversity is far more extensive than previously realized (with ancient coelacanth psmb8 lineages, shark psmb13, and tap2t and psmb10 outside the teleost MHC), implying distinct immune functions and conserved roles in shaping MHC pathway evolution throughout vertebrates. PMID:27493218

  9. Identification of cancer/testis-antigen genes by massively parallel signature sequencing

    PubMed Central

    Chen, Yao-Tseng; Scanlan, Matthew J.; Venditti, Charis A.; Chua, Ramon; Theiler, Gregory; Stevenson, Brian J.; Iseli, Christian; Gure, Ali O.; Vasicek, Tom; Strausberg, Robert L.; Jongeneel, C. Victor; Old, Lloyd J.; Simpson, Andrew J. G.

    2005-01-01

    Massively parallel signature sequencing (MPSS) generates millions of short sequence tags corresponding to transcripts from a single RNA preparation. Most MPSS tags can be unambiguously assigned to genes, thereby generating a comprehensive expression profile of the tissue of origin. From the comparison of MPSS data from 32 normal human tissues, we identified 1,056 genes that are predominantly expressed in the testis. Further evaluation by using MPSS tags from cancer cell lines and EST data from a wide variety of tumors identified 202 of these genes as candidates for encoding cancer/testis (CT) antigens. Of these genes, the expression in normal tissues was assessed by RT-PCR in a subset of 166 intron-containing genes, and those with confirmed testis-predominant expression were further evaluated for their expression in 21 cancer cell lines. Thus, 20 CT or CT-like genes were identified, with several exhibiting expression in five or more of the cancer cell lines examined. One of these genes is a member of a CT gene family that we designated as CT45. The CT45 family comprises six highly similar (>98% cDNA identity) genes that are clustered in tandem within a 125-kb region on Xq26.3. CT45 was found to be frequently expressed in both cancer cell lines and lung cancer specimens. Thus, MPSS analysis has resulted in a significant extension of our knowledge of CT antigens, leading to the discovery of a distinctive X-linked CT-antigen gene family. PMID:15905330

  10. DNA SEQUENCING, ANALYSIS, AND IDENTIFICATION OF SEROGROUP-SPECIFIC GENES IN THE ESCHERICHIA COLI O28AC AND O118 O ANTIGEN GENE CLUSTERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The DNA sequence of the O antigen gene clusters of Escherichia coli serogroups O28ac and O118 was determined, and 7 and 13 ORFs were identified, respectively, encoding genes required for O antigen sugar biosynthesis, transfer, and processing. Analysis of the DNA sequence revealed that the wzx (O ...

  11. Network-based gene expression analysis of intracranial aneurysm tissue reveals role of antigen presenting cells.

    PubMed

    Krischek, B; Kasuya, H; Tajima, A; Akagawa, H; Sasaki, T; Yoneyama, T; Ujiie, H; Kubo, O; Bonin, M; Takakura, K; Hori, T; Inoue, I

    2008-07-17

    Little is known about the pathology and pathogenesis of the rupture of intracranial aneurysms. For a better understanding of the molecular processes involved in intracranial aneurysm (IA) formation we performed a gene expression analysis comparing ruptured and unruptured aneurysm tissue to a control artery. Tissue samples of six ruptured and four unruptured aneurysms, and four cerebral arteries serving as controls, were profiled using oligonucleotide microarrays. Gene ontology classification of the differentially expressed genes was analyzed and regulatory functional networks and canonical pathways were identified with a network-based computational pathway analysis tool. Real time reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining were performed as confirmation. Analysis of aneurysmal and control tissue revealed 521 differentially expressed genes. The most significantly associated gene ontology term was antigen processing (P=1.64E-16). Further network-based analysis showed the top scoring regulatory functional network to be built around overexpressed major histocompatibility class (MHC) I and II complex related genes and confirmed the canonical pathway "Antigen Presentation" to have the highest upregulation in IA tissue (P=7.3E-10). Real time RT-PCR showed significant overexpression of MHC class II genes. Immunohistochemical staining showed strong positivity for MHC II molecule specific antibody (HLA II), for CD68 (macrophages, monocytes), for CD45RO (T-cells) and HLA I antibody. Our results offer strong evidence for MHC class II gene overexpression in human IA tissue and that antigen presenting cells (macrophages, monocytes) play a key role in IA formation. PMID:18538937

  12. Models for antigen receptor gene rearrangement: CDR3 length.

    PubMed

    Saada, Ravit; Weinberger, Moran; Shahaf, Gitit; Mehr, Ramit

    2007-06-01

    Despite the various processing steps involved in V(D)J recombination, which could potentially introduce many biases in the length distribution of complementarity determining region 3 (CDR3) segments, the observed CDR3 length distributions for complete repertoires are very close to a normal-like distribution. This raises the question of whether this distribution is simply a result of the random steps included in the process of gene rearrangement, or has been optimized during evolution. We have addressed this issue by constructing a simulation of gene rearrangement, which takes into account the DNA modification steps included in the process, namely hairpin opening, nucleotide additions, and nucleotide deletions. We found that the near-Gaussian- shape of CDR3 length distribution can only be obtained under a relatively narrow set of parameter values, and thus our model suggests that specific biases govern the rearrangement process. In both B-cell receptor (BCR) heavy chain and T-cell receptor beta chain, we obtained a Gaussian distribution using identical parameters, despite the difference in the number and the lengths of the D segments. Hence our results suggest that these parameters most likely reflect the optimal conditions under which the rearrangement process occurs. We have subsequently used the insights gained in this study to estimate the probability of occurrence of two exactly identical BCRs over the course of a human lifetime. Whereas identical rearrangements of the heavy chain are highly unlikely to occur within one human lifetime, for the light chain we found that this probability is not negligible, and hence the light chain CDR3 alone cannot serve as an indicator of B-cell clonality. PMID:17404591

  13. 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

  14. 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

  15. Form follows function - the three-dimensional structure of antigen receptor gene loci.

    PubMed

    Fugmann, Sebastian D

    2014-04-01

    Antigen receptor genes are assembled during lymphocyte development from individual gene segments by a somatic gene rearrangement process named V(D)J recombination. This process is tightly regulated to ensure the generation of an unbiased broad primary repertoire of immunoglobulins and T cell receptors, and to prevent aberrant recombination products that could initiate lymphomagenesis. One important mode of regulation that has recently been discovered for the immunoglobulin heavy chain (IGH) gene locus is the adoption of distinct three-dimensional structures of the locus. Changes in the spatial conformation are thought to ensure the appropriate access of the V(D)J recombinase machinery at each developmental stage, and the formation of extensive chromosome loops has been implicated in allowing equal access to widely dispersed gene elements. PMID:24549092

  16. Transgenic Mice Harboring SV40 T-Antigen Genes Develop Characteristic Brain Tumors

    PubMed Central

    Brinster, Ralph L.; Chen, Howard Y.; Messing, Albee; van Dyke, Terry; Levine, Arnold J.; Palmiter, Richard D.

    2016-01-01

    Summary A high percentage of transgenic mice developing from eggs microinjected with plasmids containing the SV40 early region genes and a metallothionein fusion gene develop tumors within the choroid plexus. A line of mice has been established in which nearly every affected animal succumbs to this brain tumor. Thymic hypertrophy and kidney pathology are also observed in some mice. SV40 T-antigen mRNA and protein are readily detected in affected tissues; however, SV40 T-antigen gene expression is barely detectable in unaffected tissues or in susceptible tissues prior to overt pathology, suggesting that tumorigenesis depends upon activation of the SV40 genes. Comparison of DNA from tumor tissue (or cell lines derived from tumors) with DNA from unaffected tissues reveals structural rearrangements as well as changes in DNA methylation of the foreign DNA. The SV40 genes are frequently amplified in tumor tissue, which further indicates that their expression is intimately involved in tumorigenesis in transgenic mice. PMID:6327063

  17. Induction of interferon-stimulated genes by Simian virus 40 T antigens

    SciTech Connect

    Rathi, Abhilasha V.; Cantalupo, Paul G.; Sarkar, Saumendra N.; Pipas, James M.

    2010-10-25

    Simian virus 40 (SV40) large T antigen (TAg) is a multifunctional oncoprotein essential for productive viral infection and for cellular transformation. We have used microarray analysis to examine the global changes in cellular gene expression induced by wild-type T antigen (TAg{sup wt}) and TAg-mutants in mouse embryo fibroblasts (MEFs). The expression profile of approximately 800 cellular genes was altered by TAg{sup wt} and a truncated TAg (TAg{sup N136}), including many genes that influence cell cycle, DNA-replication, transcription, chromatin structure and DNA repair. Unexpectedly, we found a significant number of immune response genes upregulated by TAg{sup wt} including many interferon-stimulated genes (ISGs) such as ISG56, OAS, Rsad2, Ifi27 and Mx1. Additionally, we also observed activation of STAT1 by TAg{sup wt}. Our genetic studies using several TAg-mutants reveal an unexplored function of TAg and indicate that the LXCXE motif and p53 binding are required for the upregulation of ISGs.

  18. Transcriptional activation by EBV nuclear antigen 1 is essential for the expression of EBV's transforming genes

    PubMed Central

    Altmann, Markus; Pich, Dagmar; Ruiss, Romana; Wang, Jindong; Sugden, Bill; Hammerschmidt, Wolfgang

    2006-01-01

    EBV is a paradigm for human tumor viruses because, although it infects most people benignly, it also can cause a variety of cancers. Both in vivo and in vitro, EBV infects B lymphocytes in G0, induces them to become blasts, and can maintain their proliferation in cell culture or in vivo as tumors. How EBV succeeds in these contrasting cellular environments in expressing its genes that control the host has not been explained. We have genetically dissected the EBV nuclear antigen 1 (EBNA1) gene that is required for replication of the viral genome, to elucidate its possible role in the transcription of viral genes. Strikingly, EBNA1 is essential to drive transcription of EBV's transforming genes after infection of primary B lymphocytes. PMID:16966603

  19. Unique antigenic gene expression at different developmental stages of Trichinella pseudospiralis.

    PubMed

    Wu, X P; Liu, X L; Wang, X L; Blaga, R; Fu, B Q; Liu, P; Bai, X; Wang, Z J; Rosenthal, B M; Shi, H N; Sandrine, L; Vallee, I; Boireau, P; Wang, F; Zhou, X N; Zhao, Y; Liu, M Y

    2013-05-20

    Parasite-induced and parasite-regulated larval capsule formation and host immunosuppression are two major characteristics that are unique in Trichinella spp. infections, but the molecule(s) and mechanism(s) that mediate these processes remain largely unknown. Trichinella pseudospiralis and Trichinella spiralis, are obviously different with respect to these two characteristics. A comparative study of these two species, in particular their antigen expression profiles at different developmental stages (the main molecules involved in the cross-talk or interaction between each parasite and its host), may help us better understand the parasite molecules and mechanisms involved. Here, we constructed cDNA libraries from T. pseudospiralis adults (Ad), newborn larvae (NBL) and muscle larvae (ML) mRNA and screened them with pig anti-T. pseudospiralis serum collected 26, 32 and 60 days post-infection (p.i.). The most abundant antigens were found to vary among life-cycle stages. Pyroglutamy peptidase 1-like and 6-phosphogluconolactonase-like genes predominated in the Ad stage and a serine protease (SS2-1-like gene) predominated in NBL similar to that observed in T. spiralis. Muscle larvae expressed proteasome activator complex subunit 3-like and 21 kDa excretory/secretory protein-like genes. This study indicated that parasites of two species may utilise different molecules and mechanisms for larvae capsule formation and host immunosuppression during their infections. Proteins of antigenic genes identified in this study may be also good candidates for diagnosis, treatment or vaccination for T. pseudospiralis infection, and also for the differential diagnosis of two species' infections. PMID:23433603

  20. Mutually Exclusive Expression of Virulence Genes by Malaria Parasites Is Regulated Independently of Antigen Production

    PubMed Central

    Dzikowski, Ron; Frank, Matthias; Deitsch, Kirk

    2006-01-01

    The primary virulence determinant of Plasmodium falciparum malaria parasite–infected cells is a family of heterogeneous surface receptors collectively referred to as PfEMP1. These proteins are encoded by a large, polymorphic gene family called var. The family contains approximately 60 individual genes, which are subject to strict, mutually exclusive expression, with the single expressed var gene determining the antigenic, cytoadherent, and virulence phenotype of the infected cell. The mutually exclusive expression pattern of var genes is imperative for the parasite's ability to evade the host's immune response and is similar to the process of “allelic exclusion” described for mammalian Ig and odorant receptor genes. In mammalian systems, mutually exclusive expression is ensured by negative feedback inhibition mediated by production of a functional protein. To investigate how expression of the var gene family is regulated, we have created transgenic lines of parasites in which expression of individual var loci can be manipulated. Here we show that no such negative feedback system exists in P. falciparum and that this process is dependent solely on the transcriptional regulatory elements immediately adjacent to each gene. Transgenic parasites that are selected to express a var gene in which the PfEMP1 coding region has been replaced by a drug-selectable marker silence all other var genes in the genome, thus effectively knocking out all PfEMP1 expression and indicating that the modified gene is still recognized as a member of the var gene family. Mutually exclusive expression in P. falciparum is therefore regulated exclusively at the level of transcription, and a functional PfEMP1 protein is not necessary for viability or for proper gene regulation in cultured parasites. PMID:16518466

  1. Genetic Analysis of the Serratia marcescens N28b O4 Antigen Gene Cluster

    PubMed Central

    Saigí, Francesc; Climent, Núria; Piqué, Núria; Sanchez, Cesar; Merino, Susana; Rubirés, Xavier; Aguilar, Alicia; Tomás, Juan M.; Regué, Miguel

    1999-01-01

    The Serratia marcescens N28b wbbL gene has been shown to complement the rfb-50 mutation of Escherichia coli K-12 derivatives, and a wbbL mutant has been shown to be impaired in O4-antigen biosynthesis (X. Rubirés, F. Saigí, N. Piqué, N. Climent, S. Merino, S. Albertí, J. M. Tomás, and M. Regué, J. Bacteriol. 179:7581–7586, 1997). We analyzed a recombinant cosmid containing the wbbL gene by subcloning and determination of O-antigen production phenotype in E. coli DH5α by sodium dodecyl sulfate-polyacrylamide electrophoresis and Western blot experiments with S. marcescens O4 antiserum. The results obtained showed that a recombinant plasmid (pSUB6) containing about 10 kb of DNA insert was enough to induce O4-antigen biosynthesis. The same results were obtained when an E. coli K-12 strain with a deletion of the wb cluster was used, suggesting that the O4 wb cluster is located in pSUB6. No O4 antigen was produced when plasmid pSUB6 was introduced in a wecA mutant E. coli strain, suggesting that O4-antigen production is wecA dependent. Nucleotide sequence determination of the whole insert in plasmid pSUB6 showed seven open reading frames (ORFs). On the basis of protein similarity analysis of the ORF-encoded proteins and analysis of the S. marcescens N28b wbbA insertion mutant and wzm-wzt deletion mutant, we suggest that the O4 wb cluster codes for two dTDP-rhamnose biosynthetic enzymes (RmlDC), a rhamnosyltransferase (WbbL), a two-component ATP-binding-cassette-type export system (Wzm Wzt), and a putative glycosyltransferase (WbbA). A sequence showing DNA homology to insertion element IS4 was found downstream from the last gene in the cluster (wbbA), suggesting that an IS4-like element could have been involved in the acquisition of the O4 wb cluster. PMID:10074083

  2. Expression of complete transplantation antigens by mammalian cells transformed with truncated class I genes.

    PubMed

    Goodenow, R S; Stroynowski, I; McMillan, M; Nicolson, M; Eakle, K; Sher, B T; Davidson, N; Hood, L

    1983-02-01

    Mouse L cells transformed with the cloned class I genes of the major histocompatibility complex of the mouse express transplantation antigens with serological determinants of the donor haplotype. However, transformation with the truncated subclones of a BALB/c H-2Ld gene containing the exons encoding the external domains also leads to the production of cells which express complete cell-surface molecules. Moreover, full-length products of the foreign haplotype, as judged by serological and biochemical criteria, are generated independently of the use of carrier DNA in transformation. However, the frequency of productive transformation is substantially less than that obtained with a complete gene. The most plausible explanation for these phenomena involves homologous recombination between host chromosomal and donor class I sequences. PMID:6823314

  3. Sir2 Paralogues Cooperate to Regulate Virulence Genes and Antigenic Variation in Plasmodium falciparum

    PubMed Central

    Duraisingh, Manoj T; Voss, Till S; Ralph, Stuart A; Hommel, Mirja; Duffy, Michael F; da Silva, Liliana Mancio; Scherf, Artur; Ivens, Alasdair; Speed, Terence P; Beeson, James G; Cowman, Alan F

    2009-01-01

    Cytoadherance of Plasmodium falciparum-infected erythrocytes in the brain, organs and peripheral microvasculature is linked to morbidity and mortality associated with severe malaria. Parasite-derived P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) molecules displayed on the erythrocyte surface are responsible for cytoadherance and undergo antigenic variation in the course of an infection. Antigenic variation of PfEMP1 is achieved by in situ switching and mutually exclusive transcription of the var gene family, a process that is controlled by epigenetic mechanisms. Here we report characterisation of the P. falciparum silent information regulator's A and B (PfSir2A and PfSir2B) and their involvement in mutual exclusion and silencing of the var gene repertoire. Analysis of P. falciparum parasites lacking either PfSir2A or PfSir2B shows that these NAD+-dependent histone deacetylases are required for silencing of different var gene subsets classified by their conserved promoter type. We also demonstrate that in the absence of either of these molecules mutually exclusive expression of var genes breaks down. We show that var gene silencing originates within the promoter and PfSir2 paralogues are involved in cis spreading of silenced chromatin into adjacent regions. Furthermore, parasites lacking PfSir2A but not PfSir2B have considerably longer telomeric repeats, demonstrating a role for this molecule in telomeric end protection. This work highlights the pivotal but distinct role for both PfSir2 paralogues in epigenetic silencing of P. falciparum virulence genes and the control of pathogenicity of malaria infection. PMID:19402747

  4. 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

  5. Characterization of the antigenic and functional domains of a Mycoplasma synoviae variant vlhA gene.

    PubMed

    Khiari, Awatef Béjaoui; Mardassi, Boutheina Ben Abdelmoumen

    2012-05-01

    The Mycoplasma synoviae haemagglutinin gene, vlhA, encodes two major immunodominant and surface-exposed membrane proteins, MSPB and MSPA. Both products are antigenically variable but only MSPA mediates binding to erythrocytes. Previously we have shown that M. synoviae type strain WVU 1853 could express a variant vlhA gene, referred to as MS2/28.1, with a considerably shorter and divergent MSPA region. A finding that prompted detailed characterization of its antigenic and functional properties. Here we mutagenized each of the six opal codons of the variant MS2/28.1 vlhA member into tryptophan, thus allowing its expression in Escherichia coli as well as its cleavage products, MSPB and MSPA. In addition, we expressed 5 contiguous regions of MS2/28.1 extending from the last part of MSPB to the C-terminus of MSPA. Colony immunostaining with region-specific antisera mapped antigenic variation to the N-terminal half of MS2/28.1 MSPA. No haemagglutinating activity was observed for MSPB, but consistent haemadsorption inhibition was mapped to the region extending from amino acid 325 to 344. Inhibition of both haemagglutination and haemadsorption activities were obtained with sera directed against the C-terminal region of MSPA, with the highest titers (1/320 and 1/160, respectively) being recorded for its last 60 residues. Importantly, antibodies to this region also yielded the highest metabolic inhibition titer of 1/1280. Overall, aside from mapping the functional domains of a M. synoviae highly divergent haemagglutinin gene, this study shows that the C-terminal half of its MSPA region induced the highest titers of antibodies inhibiting haemagglutination, haemadsorption, and metabolism. PMID:22176762

  6. Transcription analysis, physical mapping, and molecular characterization of a nonclassical human leukocyte antigen class I gene.

    PubMed Central

    Chorney, M J; Sawada, I; Gillespie, G A; Srivastava, R; Pan, J; Weissman, S M

    1990-01-01

    The human major histocompatibility complex contains approximately 20 class I genes, pseudogenes, and gene fragments. These include the genes for the three major transplantation antigens, HLA-A, HLA-B, and HLA-C, as well as a number of other genes or pseudogenes of unknown biological significance. Most of the latter have C + G-rich sequences in their 5' ends that are unmethylated in the B-lymphoblastoid cell line 3.1.0. We investigated one of these genes, HLA-H, in more detail. The gene is, overall, strongly homologous in sequence to HLA-A but differs in several potentially significant ways, including changes in conserved promoter sequences, a single-base deletion producing a translation termination codon in exon 4, and a region of sequence divergence downstream of the transcribed portion of the gene. Nevertheless, mouse L cells transfected with the gene accumulated small amounts of apparently full-length polyadenylated RNA. A portion of this RNA begins at the transcription site predicted by analogy to certain class I cDNA clones, while another portion appears to begin shortly upstream. L cells transfected with a hybrid gene containing the first three exons of HLA-H and the last five exons of HLA-B27 accumulated full-length HLA transcripts at the same level as cells transfected with an HLA-B27 gene; both levels are at least 15- to 20-fold higher than that directed by HLA-H alone. In addition, we isolated a cDNA clone for HLA-H that contains a portion of intron 3 attached to a normally spliced sequence comprising exons 4 through 8. These results suggest that low levels of translatable mRNA for the truncated class I heavy chain encoded by HLA-H are produced under physiologic circumstances and that sequences 3' of intron 3 decrease the levels of stable transcripts. Images PMID:2294403

  7. Erasing the Epigenetic Memory and Beginning to Switch—The Onset of Antigenic Switching of var Genes in Plasmodium falciparum

    PubMed Central

    Fastman, Yair; Noble, Robert; Recker, Mario; Dzikowski, Ron

    2012-01-01

    Antigenic variation in Plasmodium falciparum is regulated by transcriptional switches among members of the var gene family, each expressed in a mutually exclusive manner and encoding a different variant of the surface antigens collectively named PfEMP1. Antigenic switching starts when the first merozoites egress from the liver and begin their asexual proliferation within red blood cells. By erasing the epigenetic memory we created parasites with no var background, similar to merozoites that egress from the liver where no var gene is expressed. Creating a null-var background enabled us to investigate the onset of antigenic switches at the early phase of infection. At the onset of switching, var transcription pattern is heterogeneous with numerous genes transcribed at low levels including upsA vars, a subtype that was implicated in severe malaria, which are rarely activated in growing cultures. Analysis of subsequent in vitro switches shows that the probability of a gene to turn on or off is not associated with its chromosomal position or promoter type per se but on intrinsic properties of each gene. We concluded that var switching is determined by gene specific associated switch rates rather than general promoter type or locus associated switch rates. In addition, we show that fine tuned reduction in var transcription increases their switch rate, indicating that transcriptional perturbation can alter antigenic switching. PMID:22461905

  8. Gene Therapy Induces Antigen-Specific Tolerance in Experimental Collagen-Induced Arthritis

    PubMed Central

    Jirholt, Pernilla; Turesson, Olof; Wing, Kajsa; Holmdahl, Rikard; Kihlberg, Jan; Stern, Anna; Mårtensson, Inga-Lill; Henningsson, Louise; Gustafsson, Kenth; Gjertsson, Inger

    2016-01-01

    Here, we investigate induction of immunological tolerance by lentiviral based gene therapy in a mouse model of rheumatoid arthritis, collagen II-induced arthritis (CIA). Targeting the expression of the collagen type II (CII) to antigen presenting cells (APCs) induced antigen-specific tolerance, where only 5% of the mice developed arthritis as compared with 95% of the control mice. In the CII-tolerized mice, the proportion of Tregs as well as mRNA expression of SOCS1 (suppressors of cytokine signaling 1) increased at day 3 after CII immunization. Transfer of B cells or non-B cell APC, as well as T cells, from tolerized to naïve mice all mediated a certain degree of tolerance. Thus, sustainable tolerance is established very early during the course of arthritis and is mediated by both B and non-B cells as APCs. This novel approach for inducing tolerance to disease specific antigens can be used for studying tolerance mechanisms, not only in CIA but also in other autoimmune diseases. PMID:27159398

  9. Repression of the Drosophila proliferating-cell nuclear antigen gene promoter by zerknuellt protein

    SciTech Connect

    Yamaguchi, Masamitsu; Hirose, Fumiko; Nishida, Yasuyoshi; Matsukage, Akio )

    1991-10-01

    A 631-bp fragment containing the 5{prime}-flanking region of the Drosophila melanogaster proliferating-cell nuclear antigen (PCNA) gene was placed upstream of the chloramphenicol acetyltransferase (CAT) gene of a CAT vector. A transient expression assay of CAT activity in Drosophila Kc cells transfected with this plasmid and a set of 5{prime}-deletion derivatives revealed that the promoter function resided within a 192-bp region. Cotransfection with a zerknuellt (zen)-expressing plasmid specifically repressed CAT expression. However, cotransfection with expression plasmids for a nonfunctional zen mutation, even skipped, or bicoid showed no significant effect on CAT expression. RNase protection analysis revealed that the repression by zen was at the transcription step. The target sequence of zen was mapped within the 34-bp region of the PCNA gene promoter, even though it lacked zen protein-binding sites. Transgenic flies carrying the PCNA gene regulatory region fused with lacZ were established. These results indicate that zen indirectly represses PCNA gene expression, probably by regulating the expression of some transcription factor(s) that binds to the PCNA gene promoter.

  10. Generation of Antigenic Diversity in Plasmodium falciparum by Structured Rearrangement of Var Genes During Mitosis

    PubMed Central

    Kekre, Mihir; Otto, Thomas D.; Faizullabhoy, Adnan; Rayner, Julian C.; Kwiatkowski, Dominic

    2014-01-01

    The most polymorphic gene family in P. falciparum is the ∼60 var genes distributed across parasite chromosomes, both in the subtelomeres and in internal regions. They encode hypervariable surface proteins known as P. falciparum erythrocyte membrane protein 1 (PfEMP1) that are critical for pathogenesis and immune evasion in Plasmodium falciparum. How var gene sequence diversity is generated is not currently completely understood. To address this, we constructed large clone trees and performed whole genome sequence analysis to study the generation of novel var gene sequences in asexually replicating parasites. While single nucleotide polymorphisms (SNPs) were scattered across the genome, structural variants (deletions, duplications, translocations) were focused in and around var genes, with considerable variation in frequency between strains. Analysis of more than 100 recombination events involving var exon 1 revealed that the average nucleotide sequence identity of two recombining exons was only 63% (range: 52.7–72.4%) yet the crossovers were error-free and occurred in such a way that the resulting sequence was in frame and domain architecture was preserved. Var exon 1, which encodes the immunologically exposed part of the protein, recombined in up to 0.2% of infected erythrocytes in vitro per life cycle. The high rate of var exon 1 recombination indicates that millions of new antigenic structures could potentially be generated each day in a single infected individual. We propose a model whereby var gene sequence polymorphism is mainly generated during the asexual part of the life cycle. PMID:25521112

  11. Molecular Pathways: Breaking the Epithelial Cancer Barrier for Chimeric Antigen Receptor and T-cell Receptor Gene Therapy.

    PubMed

    Hinrichs, Christian S

    2016-04-01

    Adoptive transfer of T cells genetically engineered to express a tumor-targeting chimeric antigen receptor (CAR) or T-cell receptor (TCR) can mediate cancer regression in some patients. CARs are synthetic single-chain proteins that use antibody domains to target cell surface antigens. TCRs are natural heterodimeric proteins that can target intracellular antigens through recognition of peptides bound to human leukocyte antigens. CARs have shown promise in B-cell malignancies and TCRs in melanoma, but neither approach has achieved clear success in an epithelial cancer. Treatment of epithelial cancers may be particularly challenging because of a paucity of target antigens expressed by carcinomas and not by important healthy tissues. In addition, epithelial cancers may be protected by inhibitory ligands and soluble factors in the tumor microenvironment. One strategy to overcome these negative regulators is to modulate expression of T-cell genes to enhance intrinsic T-cell function. Programmable nucleases, which can suppress inhibitory genes, and inducible gene expression systems, which can enhance stimulatory genes, are entering clinical testing. Other work is delineating whether control of genes for immune checkpoint receptors (e.g.,PDCD1, CTLA4) and cytokine and TCR signaling regulators (e.g.,CBLB, CISH, IL12, IL15) can increase the antitumor activity of therapeutic T cells.Clin Cancer Res; 22(7); 1559-64. ©2016 AACR. PMID:27037253

  12. Structure elucidation and gene cluster characterization of the O-antigen of Escherichia coli O80.

    PubMed

    Senchenkova, Sof'ya N; Guo, Xi; Filatov, Andrei V; Perepelov, Andrei V; Liu, Bin; Shashkov, Alexander S; Knirel, Yuriy A

    2016-09-01

    Mild alkaline degradation of the lipopolysaccharide of Escherichia coli O80 afforded a polysaccharide, which was studied by sugar analysis, selective cleavage of glycosidic linkages, and (1)H and (13)C NMR spectroscopy. Solvolysis of the polysaccharide with CF3CO2H cleaved the linkages of α-Fuc and β-linked GlcNAc and GalNAc residues to give two disaccharides. The following structure of the hexasaccharide repeating unit of the O-polysaccharide was established: The polysaccharide repeat also contains a minor O-acetyl group but its position was not determined. The O-antigen gene cluster of E. coli O80 between the conserved galF and gnd genes was analyzed and found to be consistent with the O-polysaccharide structure established. PMID:27454490

  13. Structure and gene cluster of the O-antigen of Enterobacter cloacae G3421.

    PubMed

    Perepelov, Andrei V; Filatov, Andrei V; Wang, Min; Shashkov, Alexander S; Wang, Lei; Knirel, Yuriy A

    2016-06-01

    The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3421 and studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. In addition, partial solvolysis with anhydrous trifluoroacetic acid was applied, which cleaved selectively the α-l-rhamnopyranosidic linkages. The following structure of the branched hexasaccharide repeating unit was established. The O-polysaccharide studied shares the β-l-Rhap-(1→4)-α-l-Rhap-(1→2)-α-l-Rhap trisaccharide fragment with the O-polysaccharide of Shigella boydii type 18. The O-antigen gene cluster of E. cloacae G3421 was sequenced. Functions of genes in the cluster, including those for glycosyltransferases, were tentatively assigned by a comparison with sequences in the available databases and found to be consistent with the O-polysaccharide structure. PMID:27131290

  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. Detection of circulating tumor cells using GeneScan analysis for antigen receptor gene rearrangements in canine lymphoma patients

    PubMed Central

    HIYOSHI-KANEMOTO, Saaya; GOTO-KOSHINO, Yuko; FUKUSHIMA, Kenjiro; TAKAHASHI, Masashi; KANEMOTO, Hideyuki; UCHIDA, Kazuyuki; FUJINO, Yasuhito; OHNO, Koichi; TSUJIMOTO, Hajime

    2016-01-01

    The presence of circulating tumor cells (CTCs) serves as a prognostic marker and indicator of disease relapse, as well as a means of evaluating treatment efficacy in human and canine lymphoma patients. As an extension of our previous study for the construction of clinically useful GeneScan system, we utilized the GeneScan system for detecting CTCs in canine lymphoma patients. Samples from the primary lesion and peripheral blood mononuclear cells (PBMCs) were obtained from 32 dogs with lymphoma at initial diagnosis. All samples were subjected to polymerase chain reaction (PCR) for antigen receptor gene rearrangements (PARR) followed by GeneScan analysis. Common clonal rearrangements with identical amplified fragments were detected in both the primary lesion and PBMCs in 19 of the 32 dogs (59.4%). However, the detection rate of CTCs varied among the anatomical classification of lymphoma studied. GeneScan analysis following PARR would facilitate studies on determining the clinical significance of CTCs in canine lymphoma patients. PMID:26888583

  16. Topoisomerase inhibitors modulate gene expression of B-cell translocation gene 2 and prostate specific antigen in prostate carcinoma cells.

    PubMed

    Chiang, Kun-Chun; Tsui, Ke-Hung; Chung, Li-Chuan; Yeh, Chun-Nan; Chang, Phei-Lang; Chen, Wen-Tsung; Juang, Horng-Heng

    2014-01-01

    Camptothecin (CPT) and doxorubicin (DOX) have been demonstrated to have potent anti-tumor activity. The B-cell translocation gene 2 (BTG2) is involved in the regulation of cell cycle progression. We evaluated the molecular mechanisms of CPT and DOX on cell proliferation and the expressions of BTG2 and prostate specific antigen (PSA) in prostate carcinoma cells. Our results indicated that CPT or DOX treatments induced Go/G1 cell cycle arrest in LNCaP cells and apoptosis at higher dosage. Immunoblot and transient gene expression assay indicated that CPT or DOX treatments induced p53 and BTG2 gene expression, with the later effect dependent on the p53 response element within BTG2 promoter area since mutation of the p53 response element from GGGAAAGTCC to GGAGTCC or from GGCAGAGCCC to GGCACC by site-directed mutagenesis abolished the stimulation of CPT or DOX on the BTG2 promoter activity, which is also supported by our results that cotreatments of pifithrin-α, an inhibitor of p53 dependent transcriptional activation, blocked the induction of CPT or DOX on BTG2 gene expression. CPT or DOX also downregulated the protein expressions of androgen receptor (AR) and PSA. Transient gene expression assays suggested that CPT or DOX's attenuation of PSA promoter activity is dependent on both the androgen and p53 response elements within of the PSA promoter. Our results indicated that CPT and DOX attenuate cell proliferation via upregulation of BTG2 gene expression through the p53-dependent pathway. The CPT and DOX block the PSA gene expression by upregulation of p53 activity and downregulation of androgen receptor activity. PMID:24586533

  17. Topoisomerase Inhibitors Modulate Gene Expression of B-Cell Translocation Gene 2 and Prostate Specific Antigen in Prostate Carcinoma Cells

    PubMed Central

    Chung, Li-Chuan; Yeh, Chun-Nan; Chang, Phei-Lang; Chen, Wen-Tsung; Juang, Horng-Heng

    2014-01-01

    Camptothecin (CPT) and doxorubicin (DOX) have been demonstrated to have potent anti-tumor activity. The B-cell translocation gene 2 (BTG2) is involved in the regulation of cell cycle progression. We evaluated the molecular mechanisms of CPT and DOX on cell proliferation and the expressions of BTG2 and prostate specific antigen (PSA) in prostate carcinoma cells. Our results indicated that CPT or DOX treatments induced Go/G1 cell cycle arrest in LNCaP cells and apoptosis at higher dosage. Immunoblot and transient gene expression assay indicated that CPT or DOX treatments induced p53 and BTG2 gene expression, with the later effect dependent on the p53 response element within BTG2 promoter area since mutation of the p53 response element from GGGAAAGTCC to GGAGTCC or from GGCAGAGCCC to GGCACC by site-directed mutagenesis abolished the stimulation of CPT or DOX on the BTG2 promoter activity, which is also supported by our results that cotreatments of pifithrin-α, an inhibitor of p53 dependent transcriptional activation, blocked the induction of CPT or DOX on BTG2 gene expression. CPT or DOX also downregulated the protein expressions of androgen receptor (AR) and PSA. Transient gene expression assays suggested that CPT or DOX’s attenuation of PSA promoter activity is dependent on both the androgen and p53 response elements within of the PSA promoter. Our results indicated that CPT and DOX attenuate cell proliferation via upregulation of BTG2 gene expression through the p53-dependent pathway. The CPT and DOX block the PSA gene expression by upregulation of p53 activity and downregulation of androgen receptor activity. PMID:24586533

  18. Cloning of the gene coding for a shared human melanoma antigen recognized by autologous T cells infiltrating into tumor.

    PubMed Central

    Kawakami, Y; Eliyahu, S; Delgado, C H; Robbins, P F; Rivoltini, L; Topalian, S L; Miki, T; Rosenberg, S A

    1994-01-01

    By cDNA expression cloning we have isolated a gene encoding a shared human melanoma antigen recognized by HLA-A2 restricted autologous and allogenic tumor-infiltrating lymphocytes (TILs) from patients with metastatic melanoma. By using both transient and stable expression systems, transfection of this gene into non-antigen-expressing HLA-A2+ cell lines resulted in recognition by the antigen-specific TILs. The sequence of this cDNA revealed a previously undescribed putative transmembrane protein whose expression was restricted to melanoma and melanocyte cell lines and human retina but no other fresh or cultured normal tissues tested or other tumor histologies. Thus, we have identified a gene encoding a melanocyte lineage-specific protein (MART-1; melanoma antigen recognized by T cells 1) that is a widely shared melanoma antigen recognized by the T lymphocytes of patients with established malignancy. Identification of this gene opens possibilities for the development of immunotherapies for patients with melanoma. PMID:8170938

  19. Effect of Genetic Diversity in Swine Leukocyte Antigen-DRA Gene on Piglet Diarrhea

    PubMed Central

    Huang, Xiaoyu; Yang, Qiaoli; Yuan, Junhu; Liu, Lixia; Sun, Wenyang; Jiang, Yingdi; Zhao, Shengguo; Zhang, Shengwei; Huang, Wangzhou; Gun, Shuangbao

    2016-01-01

    The swine leukocyte antigens (SLAs) are the multigene families related to immune responses. Little is known about the effect of the DRA gene on diarrheal disease. This study reported the genetic diversity of the DRA gene in exons 1, 3 and 4 in 290 Chinese Yantai black pigs. No variation was identified in exon 3. In exon 1, three genotypes and two alleles were identified, generated by two single nucleotide polymorphisms (SNPs). In exon 4, there were eight genotypes and five alleles containing seven SNPs were detected with four SNPs being novel SNPs. The low polymorphism found in swine DRA is consistent with the concept that the DRA gene is highly conserved among all mammalian species. Statistical analyses indicated that the genotypes of exon 1 were not significantly associated with piglet diarrhea (p > 0.05); however, genotypes C4C4 (1.80 ± 0.33) and A4E4 (1.66 ± 0.25) of exon 4 were significantly susceptible to diarrhea (p < 0.01). These indicate that the particular genotypes of the DRA gene are susceptible to diarrheal disease, which provides valuable information for disease-resistance breeding in swine. PMID:27429004

  20. Effect of Genetic Diversity in Swine Leukocyte Antigen-DRA Gene on Piglet Diarrhea.

    PubMed

    Huang, Xiaoyu; Yang, Qiaoli; Yuan, Junhu; Liu, Lixia; Sun, Wenyang; Jiang, Yingdi; Zhao, Shengguo; Zhang, Shengwei; Huang, Wangzhou; Gun, Shuangbao

    2016-01-01

    The swine leukocyte antigens (SLAs) are the multigene families related to immune responses. Little is known about the effect of the DRA gene on diarrheal disease. This study reported the genetic diversity of the DRA gene in exons 1, 3 and 4 in 290 Chinese Yantai black pigs. No variation was identified in exon 3. In exon 1, three genotypes and two alleles were identified, generated by two single nucleotide polymorphisms (SNPs). In exon 4, there were eight genotypes and five alleles containing seven SNPs were detected with four SNPs being novel SNPs. The low polymorphism found in swine DRA is consistent with the concept that the DRA gene is highly conserved among all mammalian species. Statistical analyses indicated that the genotypes of exon 1 were not significantly associated with piglet diarrhea (p > 0.05); however, genotypes C₄C₄ (1.80 ± 0.33) and A₄E₄ (1.66 ± 0.25) of exon 4 were significantly susceptible to diarrhea (p < 0.01). These indicate that the particular genotypes of the DRA gene are susceptible to diarrheal disease, which provides valuable information for disease-resistance breeding in swine. PMID:27429004

  1. Characterization of the Aspergillus nidulans aspnd1 gene demonstrates that the ASPND1 antigen, which it encodes, and several Aspergillus fumigatus immunodominant antigens belong to the same family.

    PubMed Central

    Calera, J A; Ovejero, M C; López-Medrano, R; Segurado, M; Puente, P; Leal, F

    1997-01-01

    For the first time, an immunodominant Aspergillus nidulans antigen (ASPND1) consistently reactive with serum samples from aspergilloma patients has been purified and characterized, and its coding gene (aspnd1) has been cloned and sequenced. ASPND1 is a glycoprotein with four N-glycosidically-bound sugar chains (around 2.1 kDa each) which are not necessary for reactivity with immune human sera. The polypeptide part is synthesized as a 277-amino-acid precursor of 30.6 kDa that after cleavage of a putative signal peptide of 16 amino acids, affords a mature protein of 261 amino acids with a molecular mass of 29 kDa and a pI of 4.24 (as deduced from the sequence). The ASPND1 protein is 53.1% identical to the AspfII allergen from Aspergillus fumigatus and 48% identical to an unpublished Candida albicans antigen. All of the cysteine residues and most of the glycosylation sites are perfectly conserved in the three proteins, suggesting a similar but yet unknown function. Analysis of the primary structure of the ASPND1 coding gene (aspnd1) has allowed the establishment of a clear relationship between several previously reported A. fumigatus and A. nidulans immunodominant antigens. PMID:9119471

  2. Sequencing of the Escherichia coli O22 O Antigen Gene Cluster and Detection of E. coli Serogroups O22 and O91 by Multiplex PCR Assays Targeting Virulence Genes and the wzy Gene in the Respective O-Antigen Gene Clusters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The O antigen gene cluster of Escherichia coli O22, an extraintestinal pathogenic E. coli (ExPEC) serogroup was sequenced, and eight open reading frames encoding O antigen sugar biosynthesis, transfer, and processing were identified. Multiplex PCR assays were developed targeting the wzx and wzy gen...

  3. Gene-modified T-cell therapy using chimeric antigen receptors for pediatric hematologic malignancies.

    PubMed

    Nakazawa, Yozo

    2016-06-01

    Chimeric antigen receptor (CAR) is the generic name for synthetic T cell receptors redirected to tumor-associated antigens. Most CARs consist of an ectodomain (scFv or ligand), a hinge region, a transmembrane domain, and signaling endodomains derived from one or two co-stimulatory molecules (CD28, 4-1BB, etc) and from a CD3-ζ chain. CD19-targeted CAR T cell therapy has achieved major success in the treatment of B cell malignancies. CD19 CAR-T cells elicited complete remission in 70-90% of adult and pediatric patients with relapsed/refractory acute lymphoblastic leukemia (ALL). CD19 CAR T cell therapy from allogeneic donors including third party donors is a potential option for B-cell malignancies. CAR T cell therapies for myeloma, acute myeloid leukemia, and T-cell leukemia are still under development. Our group is currently preparing a phase I study of CD19 CAR T cell therapy in pediatric and young adult patients with ALL using a non-viral gene transfer method, the piggyBac-transposon system. PMID:27384848

  4. [Sequence of Escherichia coli O11 O-antigen gene cluster and identification of molecular markers specific to O11].

    PubMed

    Wang, Wei; Peng, Xia; Wang, Quan; Cheng, Jian-Song; Wang, Lei

    2006-06-01

    Escherichia coli O11 belongs to Shiga toxin-producing Escherichia coli (STEC), which can cause food-borne disease, hemorrhagic colitis, and hemolytic-uremic syndrome (HUS) in humans. Because of its character of specificity, the O-antigen gene cluster provides the best material for the selection of molecular markers which can be used for rapid genotyping of bacterial strain. In this study, the E.coli O11 O-antigen gene cluster was amplified by Long-range PCR and was sequenced using Shotgun-sequencing approach. Twelve open reading frames were assigned functions on the basis of homology in the E. coli O11 O-antigen gene cluster, including UDP-N-acetyl glucosamine-4-epimerase gene (gne), genes responsible for the biosynthesis of GDP-L-fucose (gmd, fcl, gmm, manC, manB), glycosyl transferase genes, O-unit flippase gene (wzx) and O-antigen polymerase gene (wzy). By polymerase chain reaction against representative stains for all the 166 E. coli and 43 Shigella O serotypes, two genes and four pairs of primers were identified to be specific to E. coli O11. Further PCR was done to detect E. coli O11 from the environmental specimens, and the sensitivities for detecting E.coli O11 from the pork and dejecta specimens were 0.25 cfu/g and 2.5 x 10(3) cfu/g, respectively. Moreover, eight probes were designed and proved to be unique to E. coli O11, which provides the basis for a sensitive test of the rapid detection of E. coli O11 by DNA microarray method. PMID:16933598

  5. Characterization and allelic variation of the transporters associated with antigen processing (TAP) genes in the domestic dog (Canis lupus familiaris).

    PubMed

    Gojanovich, Gregory S; Ross, Peter; Holmer, Savannah G; Holmes, Jennifer C; Hess, Paul R

    2013-12-01

    The function of the transporters associated with antigen processing (TAP) complex is to shuttle antigenic peptides from the cytosol to the endoplasmic reticulum to load MHC class I molecules for CD8(+) T-cell immunosurveillance. Here we report the promoter and coding regions of the canine TAP1 and TAP2 genes, which encode the homologous subunits forming the TAP heterodimer. By sampling genetically divergent breeds, polymorphisms in both genes were identified, although there were few amino acid differences between alleles. Splice variants were also found. When aligned to TAP genes of other species, functional regions appeared conserved, and upon phylogenetic analysis, canine sequences segregated appropriately with their orthologs. Transfer of the canine TAP2 gene into a murine TAP2-defective cell line rescued surface MHC class I expression, confirming exporter function. This data should prove useful in investigating the association of specific TAP defects or alleles with immunity to intracellular pathogens and cancer in dogs. PMID:23892057

  6. Characterization and allelic variation of the transporters associated with antigen processing (TAP) genes in the domestic dog (Canis lupus familiaris)

    PubMed Central

    Gojanovich, Gregory S.; Ross, Peter; Holmer, Savannah R.; Holmes, Jennifer C.; Hess, Paul R.

    2013-01-01

    The function of the transporters associated with antigen processing (TAP) complex is to shuttle antigenic peptides from the cytosol to the endoplasmic reticulum to load MHC class I molecules for CD8+ T-cell immunosurveillance. Here we report the promoter and coding regions of the canine TAP1 and TAP2 genes, which encode the homologous subunits forming the TAP heterodimer. By sampling genetically divergent breeds, polymorphisms in both genes were identified, although there were few amino acid differences between alleles. Splice variants were also found. When aligned to TAP genes of other species, functional regions appeared conserved, and upon phylogenetic analysis, canine sequences segregated appropriately with their orthologs. Transfer of the canine TAP2 gene into a murine TAP2-defective cell line rescued surface MHC class I expression, confirming exporter function. This data should prove useful in investigating the association of specific TAP defects or alleles with immunity to intracellular pathogens and cancer in dogs. PMID:23892057

  7. Adoptive Immunotherapy for Hematological Malignancies Using T Cells Gene-Modified to Express Tumor Antigen-Specific Receptors

    PubMed Central

    Fujiwara, Hiroshi

    2014-01-01

    Accumulating clinical evidence suggests that adoptive T-cell immunotherapy could be a promising option for control of cancer; evident examples include the graft-vs-leukemia effect mediated by donor lymphocyte infusion (DLI) and therapeutic infusion of ex vivo-expanded tumor-infiltrating lymphocytes (TIL) for melanoma. Currently, along with advances in synthetic immunology, gene-modified T cells retargeted to defined tumor antigens have been introduced as “cellular drugs”. As the functional properties of the adoptive immune response mediated by T lymphocytes are decisively regulated by their T-cell receptors (TCRs), transfer of genes encoding target antigen-specific receptors should enable polyclonal T cells to be uniformly redirected toward cancer cells. Clinically, anticancer adoptive immunotherapy using genetically engineered T cells has an impressive track record. Notable examples include the dramatic benefit of chimeric antigen receptor (CAR) gene-modified T cells redirected towards CD19 in patients with B-cell malignancy, and the encouraging results obtained with TCR gene-modified T cells redirected towards NY-ESO-1, a cancer-testis antigen, in patients with advanced melanoma and synovial cell sarcoma. This article overviews the current status of this treatment option, and discusses challenging issues that still restrain the full effectiveness of this strategy, especially in the context of hematological malignancy. PMID:25517545

  8. Anti-colorectal cancer effect of interleukin-2 and interferon-β fusion gene driven by carcinoembryonic antigen promoter

    PubMed Central

    Wang, Yan; Wang, Mengchun; Li, Yan

    2016-01-01

    This study was designed to investigate the antitumor effects of combined interleukin-2/interferon-β-based gene therapy in colorectal cancer. Transfection of the fusion gene expression plasmid induced significant apoptosis of Lovo cells. Additionally, the fusion gene exhibited strong inhibitory activity against tumor growth and apoptosis when being injected into the nude mice implanted with human colon cancer cells. Furthermore, the tail-vein injection showed a more notable effect than direct injection into tumor. These results suggest that the combined interleukin-2/interferon-β-based gene therapy with the carcinoembryonic antigen promoter might be an effective antitumor strategy. PMID:27313471

  9. An immobilization antigen gene of the fish-parasitic protozoan Ichthyophthirius multifiliis strain ARS-6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyophthirius multifiliis (Ich) is a severe fish parasite that causes ‘white spot’ disease in many freshwater fish and leads to high mortality. The antigens on the parasite surface are involved in the antibody-mediated immobilization and hence designated as immobilization antigens (i-antigens). ...

  10. HLA-DR, DQ and T cell antigen receptor constant beta genes in Japanese patients with ulcerative colitis.

    PubMed Central

    Kobayashi, K; Atoh, M; Konoeda, Y; Yagita, A; Inoko, H; Sekiguchi, S

    1990-01-01

    We studied the T cell antigen receptor (TcR) constant beta chain genes on HLA typed Japanese patients with ulcerative colitis (UC). A TcR constant beta EcoRI 6.0-kb fragment was present in all Japanese UC patients (n = 17) but completely absent in the controls (n = 35) (chi2 = 47.6, P less than 0.001). The frequency of HLA-DR2 antigen was significantly higher in UC patients (85% versus 28% in controls, P less than 0.001). Furthermore, HLA-DQw1 antigen was also increased in UC patients (96% versus 60% in controls, P less than 0.001). However, HLA-DR4 antigen was significantly decreased in UC patients (12% versus 37%, P = 0.02). HLA-DR1 antigen was not found in UC patients and was present in only 15% of the controls. These results suggest that TcR beta chain and HLA-DQw1 antigen may be important in the pathogenesis of Japanese UC. Images Fig. 1 PMID:1973647

  11. 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

  12. Characterization of a cancer/testis (CT) antigen gene family capable of eliciting humoral response in cancer patients

    PubMed Central

    Parmigiani, Raphael B.; Bettoni, Fabiana; Vibranovski, Maria D.; Lopes, Marilene H.; Martins, Waleska K.; Cunha, Isabela W.; Soares, Fernando A.; Simpson, Andrew J. G.; de Souza, Sandro J.; Camargo, Anamaria A.

    2006-01-01

    Cancer/testis (CT) antigens are immunogenic proteins expressed in normal gametogenic tissues and in different types of tumors. CT antigens are promising candidates for cancer immunotherapy, and the identification of novel CT antigens is a prerequisite for the development of cancer vaccines. We have identified a CT antigen, named CTSP-1, with partial similarity to the breast differentiation antigen NY-BR-1. CTSP-1 presents several splicing and polyadenylation variants and has a very restricted expression pattern among normal tissues. CTSP-1 is exclusively expressed in normal testis and is aberrantly expressed in 47.6% (10 of 21) of tumor cell lines and in 44.4% (75 of 169) of tumors from different histological types. The highest percentages of positive expression were observed in melanomas (59.0%) followed by prostate (58.0%) and lung (57.0%) tumors. CTSP-1 is part of a highly conserved gene family, and members of this family also have a restricted expression pattern and similar protein structure. Antibodies against members of this gene family were detected in 10% (14 of 141) of plasma samples from patients with a wide spectrum of tumors. The highest percentages of antibody response were observed in patients with prostate (20.8%), thyroid (20.0%), and breast (16.6%) tumors. Because of its very restricted expression pattern in normal tissues and immunogenicity in different types of tumors, CTSP-1 should be considered a promising candidate for cancer immunotherapy. PMID:17114284

  13. Proliferating cell nuclear antigen (Pcna) as a direct downstream target gene of Hoxc8

    SciTech Connect

    Min, Hyehyun; Lee, Ji-Yeon; Bok, Jinwoong; Chung, Hyun Joo; Kim, Myoung Hee

    2010-02-19

    Hoxc8 is a member of Hox family transcription factors that play crucial roles in spatiotemporal body patterning during embryogenesis. Hox proteins contain a conserved 61 amino acid homeodomain, which is responsible for recognition and binding of the proteins onto Hox-specific DNA binding motifs and regulates expression of their target genes. Previously, using proteome analysis, we identified Proliferating cell nuclear antigen (Pcna) as one of the putative target genes of Hoxc8. Here, we asked whether Hoxc8 regulates Pcna expression by directly binding to the regulatory sequence of Pcna. In mouse embryos at embryonic day 11.5, the expression pattern of Pcna was similar to that of Hoxc8 along the anteroposterior body axis. Moreover, Pcna transcript levels as well as cell proliferation rate were increased by overexpression of Hoxc8 in C3H10T1/2 mouse embryonic fibroblast cells. Characterization of 2.3 kb genomic sequence upstream of Pcna coding region revealed that the upstream sequence contains several Hox core binding sequences and one Hox-Pbx binding sequence. Direct binding of Hoxc8 proteins to the Pcna regulatory sequence was verified by chromatin immunoprecipitation assay. Taken together, our data suggest that Pcna is a direct downstream target of Hoxc8.

  14. Gene frequencies of human platelet antigens 1-5 in indigenous Australians in Western Australia.

    PubMed

    Bennett, J A; Palmer, L J; Musk, A W; Erber, W N

    2002-06-01

    The frequencies of human platelet antigen (HPA) systems vary between different racial groups; however, HPA frequency data for some racial groups are still incomplete. We report the distribution of HPA 1-5 systems in Australian Aborigines from a remote community in the north-west of Australia and compare our findings with HPA observed in a Western Australian blood donor population. Using a polymerase chain reaction (PCR) with sequence-specific primers, 185 indigenous Australians and 1000 Western Australian blood donors were genotyped for each of the HPA 1-5 systems. Comparison of gene frequencies of alleles from HPA-1, -2, -3 and -5 systems showed significant differences between Aboriginal people and Western Australian blood donors (P < 0.001). In particular, the frequency of HPA-3b (0.068) in the Australian Aboriginals, from this study, was one of the lowest reported, whilst the frequency of HPA-5b (0.246) was one of the highest for this allele. Gene frequencies were similar to those reported for central Australian Aborigines but with no other ethnic group. In conclusion, this study confirms significant differences in HPA distributions between indigenous Australians, Australian blood donors and other racial groups. These results indicate a higher potential risk of alloimmunization to HPA-1, -2 and -3 in Australian Aborigines receiving transfusion therapy from a Caucasian blood donor population, thereby having practical implications for transfusion and pregnancy risks in people of Aboriginal origin. PMID:12071877

  15. Gene cloning, expression, and localization of antigen 5 in the life cycle of Echinococcus granulosus.

    PubMed

    Li, Yuzhe; Xu, Hongxu; Chen, Jiajia; Gan, Wenjia; Wu, Weihua; Wu, Weiping; Hu, Xuchu

    2012-06-01

    Antigen 5 (Ag5) has been identified as a dominant component of cyst fluid of Echinococcus granulosus and is considered as a member of serine proteases family, which in other helminth, plays an important role in the egg hatch and larva invasion. However, whether Ag5 is expressed and secreted in all life stages is unknown. In this study, according to the sequence in GenBank, we cloned and sequenced the open reading frame (ORF) of Ag5 gene from the protoscolices of E. granulosus isolated from the sheep in Qinhai Province of China, and found several substitutions and a base insert and deletion in a short region near the stop code, leading to a frameshift mutation which is conserved with the homologue of other cestode. The ORF is 1,455 bp in length, encoding 484 amino acids with a secretory signal peptide. Bioinformatics analysis predicted several phosphorylation and myristoylation sites and a N-glycosylation site and a species-specific linear B epitope in the protein. The ORF was cloned into the plasmid pET28a(+) vector and expressed in Escherichia coli . The recombinant protein was purified by affinity chromatography. Anti-rEgAg5 antiserum was prepared in rats and used to analyze the localization of Ag5 in protoscolex and adult worm by immunofluorescence technique. Results demonstrated that the Ag5 is strongly expressed in the tegument of protoscolex and the embryonic membrane of egg and surface of oncosphere; meanwhile, it is also weakly expressed in tegument of the adult. This study showed that Ag5 is expressed in all stages of life cycle, secreted from the surface of the worm and may be anchored in membrane by its myristoylation sites; these characteristics make it a candidate antigen for diagnosis and vaccine for both intermediate and definitive hosts. PMID:22200957

  16. T antigen expression and tumorigenesis in transgenic mice containing a mouse major urinary protein/SV40 T antigen hybrid gene.

    PubMed Central

    Held, W A; Mullins, J J; Kuhn, N J; Gallagher, J F; Gu, G D; Gross, K W

    1989-01-01

    A hybrid mouse major urinary protein (MUP)/SV40 T antigen gene was microinjected into fertilized mouse embryos and the resulting transgenic mice analyzed for the regulated expression of the transgene. Available evidence indicates that the MUP gene used for the hybrid gene construct is expressed in both male and female liver and possibly mammary gland. Three different transgenic lines exhibited a consistent pattern of tissue specific expression of the transgene. As a consequence of transgene expression and T antigen synthesis in the liver, both male and female transgenic animals developed liver hyperplasia and tumors. Transgene expression and liver hyperplasia commenced at approximately 2-4 weeks of age, the same time that MUP gene expression is first detected in the liver. The expression of the transgene resulted in an immediate strong suppression of liver MUP mRNA levels but had relatively little effect on other liver specific mRNAs. From 4 to 8 weeks, the liver increased several fold in size, relative to non-transgenic littermates. Definitive tumor nodules were not apparent until 8-10 weeks. The transgene was also consistently found to be expressed in the skin sebaceous glands and the preputial gland, a modified sebaceous gland. The expression of the transgene in the skin sebaceous glands is consistent with the presence of MUP mRNA in the skin and a putative role for MUPs in the transport and excretion of small molecules. Occasional expression of the transgene in other tissues (kidney and mammary connective tissues) was also noted.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:2714250

  17. [Novel therapy for malignant lymphoma: adoptive immuno-gene therapy using chimeric antigen receptor(CAR)-expressing T lymphocytes].

    PubMed

    Ozawa, Keiya

    2014-03-01

    Adoptive T-cell therapy using chimeric antigen receptor (CAR) technology is a novel approach to cancer immuno-gene therapy. CARs are hybrid proteins consisting of target-antigen-specific single-chain antibody fragment fused to intracellular T-cell activation domains (CD28 or CD137/CD3 zeta receptor). CAR-expressing engineered T lymphocytes can directly recognize and kill tumor cells in an HLA independent manner. In the United States, promising results have been obtained in the clinical trials of adoptive immuno-gene therapy using CD19-CAR-T lymphocytes for the treatment of refractory B-cell malignancies, including chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL). In this review article, CD19-CAR-T gene therapy for refractory B-cell non-Hodgkin lymphoma is discussed. PMID:24724418

  18. Localization and physical mapping of the prostate-specific membrane antigen (PSM) gene to human chromosome 11

    SciTech Connect

    Rinker-Schaeffer, C.W.; Hawkins, A.L.; Griffin, C.A.; Isaacs, J.T.

    1995-11-01

    The prostate-specific membrane antigen (PSM) was identified by the monoclonal antibody 7E11-C5.3, which was raised against the human prostatic carcinoma cell line LNCaP. The PSM antigen is expressed by normal, neoplastic, and metastatic prostatic tissues. The 2.65-kb cDNA encoding the 100-kDa PSM glycoprotein was cloned from LNCaP cells. Studies have shown that the expression of PSM is tissue-specific. In the present study monochromosomal somatic cell hybrids were used to localize the PSM gene to human chromosome 11. Using this information, initial mapping studies identified two potential PSM gene loci at 11p11.1-p13 and 11q14. Further high-stringency analysis using cosmid probes identified the 11q14 region as the location of the PSM gene. 10 refs., 2 figs.

  19. 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

  20. Association of Polymorphisms in HLA Antigen Presentation-Related Genes with the Outcomes of HCV Infection

    PubMed Central

    Lu, Xiaomei; Xu, Yin; Wang, Jie; Zhang, Yun; Yu, Rongbin; Su, Jing

    2015-01-01

    Antigen-presentation genes play a vital role in the pathogenesis of HCV infection. However, the relationship of variants of these genes with spontaneous outcomes of HCV infection has not been fully investigated. To explore novel loci in the Chinese population, 34 tagging-SNPs in 9 candidate genes were genotyped for their associations with the outcomes of HCV infection. The distributions of different genotypes and haplotypes were compared among 773 HCV-negative controls, 246 subjects with HCV natural clearance, and 218 HCV persistent carriers recruited from hemodialysis patients and intravenous drug users. Our study implicated that TAP2, HLA-DOA, HLA-DOB, and tapasin loci were novel candidate regions for susceptibility to HCV infection and viral clearance in the Chinese population. Logistic regression analyses showed that TAP2 rs1800454 A (OR = 1.48, P = 0.002) and HLA-DOB rs2071469 G (OR = 1.23, P = 0.048) were significantly associated with increased susceptibility to establishment of HCV infection. However, high-risk behavior exposure and age were stronger predictors of HCV infection. Mutation of tapasin rs9277972 T (OR = 1.57, P =0.043) increased the risk of HCV chronicity, and HLA-DOA rs3128935 C (OR = 0.62, P = 0.019) increased the chance of viral resolution. With regards to the effect of rs3128925, interactions were found with high-risk behavior (P = 0.013) and age (P = 0.035). The risk effect of rs3128925 T for persistent HCV infection was higher in injecting drug users (vs. dialysis patients) and in subjects ≥ 40 years old (vs. < 40 years old). PMID:25874709

  1. In silico prediction of tumor antigens derived from functional missense mutations of the cancer gene census

    PubMed Central

    Khalili, Jahan S.; Hanson, Russell W.; Szallasi, Zoltan

    2012-01-01

    Antigen-specific immune responses against peptides derived from missense gene mutations have been identified in multiple cancers. The application of personalized peptide vaccines based on the tumor mutation repertoire of each cancer patient is a near-term clinical reality. These peptides can be identified for pre-validation by leveraging the results of massive gene sequencing efforts in cancer. In this study, we utilized NetMHC 3.2 to predict nanomolar peptide binding affinity to 57 human HLA-A and B alleles. All peptides were derived from 5,685 missense mutations in 312 genes annotated as functionally relevant in the Cancer Genome Project. Of the 26,672,189 potential 8–11 mer peptide-HLA pairs evaluated, 0.4% (127,800) display binding affinities < 50 nM, predicting high affinity interactions. These peptides can be segregated into two groups based on the binding affinity to HLA proteins relative to germline-encoded sequences: peptides for which both the mutant and wild-type forms are high affinity binders, and peptides for which only the mutant form is a high affinity binder. Current evidence directs the attention to mutations that increase HLA binding affinity, as compared with cognate wild-type peptide sequences, as these potentially are more relevant for vaccine development from a clinical perspective. Our analysis generated a database including all predicted HLA binding peptides and the corresponding change in binding affinity as a result of point mutations. Our study constitutes a broad foundation for the development of personalized peptide vaccines that hone-in on functionally relevant targets in multiple cancers in individuals with diverse HLA haplotypes. PMID:23243591

  2. Cytotoxic T Lymphocyte Antigen-4 Gene Variants in Type 2 Diabetic Patients with or without Neuropathy.

    PubMed

    Kiani, Javad; Khadempar, Saedeh; Hajilooi, Mehrdad; Rezaei, Hamzeh; Keshavarzi, Fatemeh; Solgi, Ghasem

    2016-06-01

    Many studies have shown that cytotoxic T lymphocyte antigen-4 (CTLA-4) gene variants are associated with several autoimmune diseases particularly type 1 diabetes. Due to the lack of consistent data for this association with type 2 diabetes (T2D), this study explored the possible influence of CTLA-4 gene polymorphisms at -1722 (T/C), -318 (C/T), and +49 (G/A) positions for susceptibility to T2D in relation with neuropathy. One hundred and eleven unrelated patients with T2D [49 patients with diabetic peripheral neuropathy (DPN) and 62 patients without PDN] and 100 healthy ethnic- and gender-matched controls were included in this study. The dimorphisms at -1722 (C/T), -318 (C/T) and +49 (A/G) for CTLA-4 gene were determined using ARMS-PCR. The CTLA-4 (+49 G/G) and (+49 A/A) genotypes were found to be positively and negatively associated with T2D, respectively (p=0.03). The -318 C/T and T/T genotypes were more frequent in patients than controls and -318 C/C genotype was shown to be protective for T2D (p=0.003). ACT and GTT Haplotypes were less and more frequent in controls and patients, respectively (p=3.86×10-7 and p=2.29×10-5). Genotypes distribution among T2D patients with and without DPN compared to healthy controls showed significantly lower frequencies for -318 C/C and +49 A/A genotypes and significantly higher frequencies for -318 C/T and T/T genotypes as well. Our findings indicate that CTLA-4 (+49 A/G) and (-318 C/T) genotypes could be considered as genetic risk factors associated with susceptibility or protection for T2D. PMID:27424137

  3. Structure and antigenicity analysis of the IgG gene for Nyctereutes procyonoides

    PubMed Central

    Zhao, Cui; Guo, Shuyuan; Pang, Xiaoru; Song, Daozhen; Fu, Shijun

    2015-01-01

    Objective Nyctereutes procyonoides immunoglobulin G (IgG) gene is partially cloned. Material and methods In order to obtain a certain length (966bp) of Nyctereutes procyonoides immunoglobulin G (IgG), two pairs of primers are designed according to the conserved nucleotide sequence of canine (GenBank:AF354265, AF354265, AF354266, AF354267) and mink (GenBank: L07789). Using Bioinformatics technology and Western-blot to analyze antigenicity of Nyctereutes procyonoides IgG-B gene. Results The homology for nucleotide sequence of IgG between Nyctereutes procyonoides and canine (IgG A, IgG B, IgG C, IgG D), mink, Homo sapiens, Oryctolagus cuniculus, Mus musculus, Anas platyrhynchos and gallus were respectively (88.1%, 93.6%, 85.4%, 87.2%), 83.7%, 74.8%, 71.8%, 69.2%, 51.6%, 48.4%. It can be seen that there was high homology of aminoacid sequence between IgG of Nyctereutes procyonoides and IgG (A, B, C, D) of canine. And the serum antibody of Nyctereutes procyonoides had obviously cross-reaction with HRP conjugated rabbit anti-dog IgG, compared with those of canine, oryctolagus cuniculus, mus musculus, mink, gallus. Conclusions We successfully got Nyctereutes procyonoides immuneglobulin G (IgG) gene (Gen- Bank: KM010191). There is the closest ties of consanguinity of IgG exist between Nyctereutes procyonoides and canine among the mammal through the genetic evolution. The detection and treament of canine distemper can be used on Nyctereutes procyonoides. PMID:26648768

  4. Novel meningococcal 4CMenB vaccine antigens - prevalence and polymorphisms of the encoding genes in Neisseria gonorrhoeae.

    PubMed

    Hadad, Ronza; Jacobsson, Susanne; Pizza, Mariagrazia; Rappuoli, Rino; Fredlund, Hans; Olcén, Per; Unemo, Magnus

    2012-09-01

    The first cross-protective Neisseria meningitidis vaccine (focus on serogroup B), the protein-based 4 component meningococcus serogroup B (4CMenB), includes the New Zealand outer membrane vesicle and three main genome-derived neisserial antigens (GNAs). These GNAs are fHbp (fused to GNA2091), NHBA (fused to GNA1030) and NadA. In this study, the prevalence and polymorphisms of the nucleotide and amino acid sequences of the 4CMenB antigens in a temporally and geographically diverse collection of N. gonorrhoeae isolates (n = 111) were investigated. All the examined GNA genes, except the nadA gene, were present in all gonococcal isolates. However, 25 isolates contained premature stop codons in the fHbp gene and/or the nhba gene, resulting in truncated proteins. Compared with the 4CMenB antigen sequences in reference strain MC58, the gonococcal strains displayed 67.0-95.4% and 60.9-94.9% identity in nucleotide sequence and amino acid sequence, respectively, in the equivalent GNA antigens. The absence of NadA, lack of universal expression of fHbp and NHBA and the uncertainty regarding the surface exposure of fHbp as well as the function of NHBA in N. gonorrhoeae will likely limit the use of the identical 4CMenB antigens in a gonococcal vaccine. However, possible cross-immunity of 4CMenB with gonococci and expression and function of the equivalent gonococcal GNAs, as well as of more appropriate GNAs for a gonococcal vaccine, need to be further examined. PMID:22882265

  5. Cloning and sequence analysis of the Schistosoma mansoni membrane glycoprotein antigen gene GP22.

    PubMed

    el-Sherbeini, M; Ramadan, N; Bostian, K A; Knopf, P M

    1991-11-01

    A family of Schistosoma mansoni proteins (18-22 kDa, pI 5.3-5.8) are biosynthesized in juvenile worms and immunoprecipitated by antibodies uniquely present in protective Fischer rat antiserum. A cDNA clone, lambda gt11-40, expressing epitopes common to this protein family was used to obtain a genomic DNA clone, by hybridization with a lambda gt11-40 oligonucleotide probe. In the 1.37 kb of genomic DNA sequenced, an open reading frame of 182 amino acids was identified on the strand corresponding to lambda gt11-40 coding sequences, and those of identical independently isolated cDNA clones defining a 25-kDa surface membrane glycoprotein. The new S. mansoni gene is termed GP22. There are two candidate promoters, confirmed by primer extension studies with worm RNA. Promoter 1 (P1) is preceded by a G + C-rich region and potential CAAT sequences, and is to the 5'-side of P2. Transcription from P1 is initiated at 2 different sites, apparently producing mRNAs with different translation start sites (ATG). Decoding these mRNAs yields protein products of 182 (P1), 175 (P1), 140 (P2) and 136 (P2) amino acids. The polypeptides share the following features: a hydrophobic segment near the carboxy terminus sufficient to span a lipid bilayer, with a consensus sequence for thio-esterification by a fatty acid; an external domain containing 2 potential N-linked glycosylation sites; and a candidate leucine-zipper motif, suggesting the protein may exist as a dimer on the worm surface. While sharing these common features in their carboxy terminal regions, the three proteins differ in the length and properties of their amino termini. The 140-amino acid protein has a short hydrophobic amino terminus, while the 175- and 182-amino acid proteins have more extensive hydrophobic sequences, each preceded by a hydrophilic amino terminal sequence. The heterogeneity observed in 2-dimensional gels of the antigen may be explained in part by the size and charge differences among the proteins deduced

  6. Cloning and sequencing of the gene for alpha antigen from Mycobacterium avium and mapping of B-cell epitopes.

    PubMed Central

    Ohara, N; Matsuo, K; Yamaguchi, R; Yamazaki, A; Tasaka, H; Yamada, T

    1993-01-01

    The complete nucleotide sequence of alpha antigen secreted from Mycobacterium avium (A-alpha) was determined. The gene encodes 330 amino acids, including 40 amino acids for the signal peptide, followed by 290 amino acids for the mature protein with a molecular mass of 30,811 Da. This is the first sequence of A-alpha. Comparisons between A-alpha and alpha antigens of Mycobacterium leprae, Mycobacterium bovis BCG, and Mycobacterium kansasii showed highly homologous regions which suggested a conserved functional domain and two less-homologous regions. Serological analysis of recombinant A-alpha, expressed by a series of deletion constructs, indicated the possibility that A-alpha carries at least six B-cell epitopes. The three antigenic determinants were common to Mycobacterium tuberculosis, M. kansasii, and M. avium. The results also suggested the possibility that there are three species-specific epitopes. Images PMID:7681039

  7. Highly specific expression of luciferase gene in lungs of naive nude mice directed by prostate-specific antigen promoter

    SciTech Connect

    Li Hongwei; Li Jinzhong; Helm, Gregory A.; Pan Dongfeng . E-mail: Dongfeng_pan@yahoo.com

    2005-09-09

    PSA promoter has been demonstrated the utility for tissue-specific toxic gene therapy in prostate cancer models. Characterization of foreign gene overexpression in normal animals elicited by PSA promoter should help evaluate therapy safety. Here we constructed an adenovirus vector (AdPSA-Luc), containing firefly luciferase gene under the control of the 5837 bp long prostate-specific antigen promoter. A charge coupled device video camera was used to non-invasively image expression of firefly luciferase in nude mice on days 3, 7, 11 after injection of 2 x 10{sup 9} PFU of AdPSA-Luc virus via tail vein. The result showed highly specific expression of the luciferase gene in lungs of mice from day 7. The finding indicates the potential limitations of the suicide gene therapy of prostate cancer based on selectivity of PSA promoter. By contrary, it has encouraging implications for further development of vectors via PSA promoter to enable gene therapy for pulmonary diseases.

  8. Molecular Characterization of the Escherichia coli Serogroup O117, O126, and O146 O Antigen Gene Clusters and Development of PCR Assays Targeting Serogroup O117-, O126-, and O146-Specific DNA Sequences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The O antigen gene clusters of Escherichia coli serogroups O117, O126, and O146 were sequenced, and eleven, ten, and eleven open reading frames (ORFs) were identified, respectively. Genes required for O antigen sugar biosynthesis, sugar transfer and sugar processing in these O-antigen gene clusters...

  9. Determination of serotyping antigens, clonal analysis and genetic characterization of the 4CMenB vaccine antigen genes in invasive Neisseria meningitidis from Western Canada, 2009 to 2013.

    PubMed

    Law, Dennis K S; Zhou, Jianwei; Deng, Saul; Hoang, Linda; Tyrrell, Gregory; Horsman, Greg; Wylie, John; Tsang, Raymond S W

    2014-11-01

    This study examined invasive Neisseria meningitidis recovered from invasive meningococcal disease (IMD) cases in Western Canada between 2009 and 2013. A total of 161 isolates from individual IMD cases were analysed for serogroup, serotype, serosubtype, PorA genotype, multi-locus sequence type and nucleotide sequence of their 4CMenB vaccine antigen genes. Sixty-nine isolates were serogroup B (MenB), 47 were serogroup Y (MenY), 22 were serogroup C (MenC), 19 were serogroup W (MenW), three were serogroup E and one was non-encapsulated. MenC, MenY and MenW were mainly clonal, represented primarily by clonal complex (cc) 11, cc23 or cc167, and cc22, respectively. In contrast, MenB were composed of eight different ccs together with 11 isolates not assigned to any known cc. Antigenic analysis and PorA genotyping confirmed the heterogeneity of MenB isolates, while such results supported the clonal nature of most MenC, MenY and MenW isolates. Thirty-four (21.1%) isolates had at least one gene that encoded one matching vaccine protein component of the 4CMenB vaccine (i.e. PorA P1.4; fHbp variant 1.1; NHBA peptide 2; and NadA-1, -2, or -3). An additional 18 isolates had genes that encoded variant 1 or subfamily B factor H binding proteins of this same vaccine. PMID:25165123

  10. Peripherin: an islet antigen that is cross-reactive with nonobese diabetic mouse class II gene products.

    PubMed Central

    Boitard, C; Villa, M C; Becourt, C; Gia, H P; Huc, C; Sempe, P; Portier, M M; Bach, J F

    1992-01-01

    The nonobese diabetic (NOD) mouse, in which major histocompatibility complex genes may be involved in the susceptibility to diabetes, has been developed as a model of autoimmune diabetes. The NOD mouse expresses I-A-encoded class II major histocompatibility complex antigens, which differ from those of other mouse haplotypes by the presence of a serine at position 57 of the A beta chain. Identifying islet autoantigens may help elucidate the role of class II antigens in the activation of autoreactive T cells and, thus, in the development of diabetes. We have detected autoantibodies directed against a 58-kDa islet cell antigen in NOD mice but not in other strains, including lupus-prone mice. Apart from insulin-secreting cells, the 58-kDa antigen was only found to be expressed by neuroblastoma cells and was identified as peripherin, an intermediate filament protein previously characterized in well-defined neuronal populations. This autoantigen cross-reacted with I-Anod class II antigens, suggesting that it may contribute to defective self-tolerance of islet beta cells in the NOD mouse. Images PMID:1729686

  11. The evolutionary dynamics of variant antigen genes in Babesia reveal a history of genomic innovation underlying host–parasite interaction

    PubMed Central

    Jackson, Andrew P.; Otto, Thomas D.; Darby, Alistair; Ramaprasad, Abhinay; Xia, Dong; Echaide, Ignacio Eduardo; Farber, Marisa; Gahlot, Sunayna; Gamble, John; Gupta, Dinesh; Gupta, Yask; Jackson, Louise; Malandrin, Laurence; Malas, Tareq B.; Moussa, Ehab; Nair, Mridul; Reid, Adam J.; Sanders, Mandy; Sharma, Jyotsna; Tracey, Alan; Quail, Mike A.; Weir, William; Wastling, Jonathan M.; Hall, Neil; Willadsen, Peter; Lingelbach, Klaus; Shiels, Brian; Tait, Andy; Berriman, Matt; Allred, David R.; Pain, Arnab

    2014-01-01

    Babesia spp. are tick-borne, intraerythrocytic hemoparasites that use antigenic variation to resist host immunity, through sequential modification of the parasite-derived variant erythrocyte surface antigen (VESA) expressed on the infected red blood cell surface. We identified the genomic processes driving antigenic diversity in genes encoding VESA (ves1) through comparative analysis within and between three Babesia species, (B. bigemina, B. divergens and B. bovis). Ves1 structure diverges rapidly after speciation, notably through the evolution of shortened forms (ves2) from 5′ ends of canonical ves1 genes. Phylogenetic analyses show that ves1 genes are transposed between loci routinely, whereas ves2 genes are not. Similarly, analysis of sequence mosaicism shows that recombination drives variation in ves1 sequences, but less so for ves2, indicating the adoption of different mechanisms for variation of the two families. Proteomic analysis of the B. bigemina PR isolate shows that two dominant VESA1 proteins are expressed in the population, whereas numerous VESA2 proteins are co-expressed, consistent with differential transcriptional regulation of each family. Hence, VESA2 proteins are abundant and previously unrecognized elements of Babesia biology, with evolutionary dynamics consistently different to those of VESA1, suggesting that their functions are distinct. PMID:24799432

  12. 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

  13. 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

  14. Detection of Cytotoxic T-Lymphocyte Associated Antigen-4 Gene Polymorphism in Type 1 Diabetes Mellitus.

    PubMed

    Arafa, Roshdan M; Desouky, Somaya M; Emam, Sherin M; Abed, Neveen Tawfik; Mohamed, Sahar Y

    2015-01-01

    Type 1 diabetes is one of the most common chronic childhood illnesses. Interplay between genetic susceptibility and environmental factors is thought to provide the fundamental element for the disease. It has been shown that more than 40 genetic loci are associated with T1DM. Important one among these is the CTLA-4. This work aimed to detect Cytotoxic T Lymphocyte-associated antigen 4 (CTLA-4) gene polymorphism in patients with type 1 diabetes mellitus T1DM using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to clarify its role in the susceptibility to T1DM. The study was carried out on forty unrelated Egyptian children with TIDM. Twenty unrelated healthy children were enrolled as a control group. Blood samples were collected from patients and control groups and subjected to CTLA-4 gene polymorphism analysis using polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP). CTLA-4 G allele and GG homozygous genotype were significantly increased in T1DM patients than in control group (P < 0.001, P = 0.002 respectively). There was significant association between the three CTLA-4 genotypes (AA, AG, GG) and diabetic complications (p = 0.002), AG and GG polymorphisms were associated with complications of diabetes with ratio 84.6% and 100% respectively. While no association was found with sex, weight, height, risk factors of diabetes or insulin treatment. It was concluded that there is a strong association between AG polymorphism and T1DM (P = 0.002). PMID:26415372

  15. Epigenetic aspects of lymphocyte antigen receptor gene rearrangement or 'when stochasticity completes randomness'.

    PubMed

    Jaeger, Sébastien; Fernandez, Bastien; Ferrier, Pierre

    2013-06-01

    To perform their specific functional role, B and T lymphocytes, cells of the adaptive immune system of jawed vertebrates, need to express one (and, preferably, only one) form of antigen receptor, i.e. the immunoglobulin or T-cell receptor (TCR), respectively. This end goal depends initially on a series of DNA cis-rearrangement events between randomly chosen units from separate clusters of V, D (at some immunoglobulin and TCR loci) and J gene segments, a biomolecular process collectively referred to as V(D)J recombination. V(D)J recombination takes place in immature T and B cells and relies on the so-called RAG nuclease, a site-specific DNA cleavage apparatus that corresponds to the lymphoid-specific moiety of the VDJ recombinase. At the genome level, this recombinase's mission presents substantial biochemical challenges. These relate to the huge distance between (some of) the gene segments that it eventually rearranges and the need to achieve cell-lineage-restricted and developmentally ordered routines with at times, mono-allelic versus bi-allelic discrimination. The entire process must be completed without any recombination errors, instigators of chromosome instability, translocation and, potentially, tumorigenesis. As expected, such a precisely choreographed and yet potentially risky process demands sophisticated controls; epigenetics demonstrates what is possible when calling upon its many facets. In this vignette, we will recall the evidence that almost from the start appeared to link the two topics, V(D)J recombination and epigenetics, before reviewing the latest advances in our knowledge of this joint venture. PMID:23278765

  16. Identification of Actinobacillus pleuropneumoniae Genes Preferentially Expressed During Infection Using In Vivo-Induced Antigen Technology (IVIAT).

    PubMed

    Zhang, Fei; Zhang, Yangyi; Wen, Xintian; Huang, Xiaobo; Wen, Yiping; Wu, Rui; Yan, Qigui; Huang, Yong; Ma, Xiaoping; Zhao, Qin; Cao, Sanjie

    2015-10-01

    Porcine pleuropneumonia is an infectious disease caused by Actinobacillus pleuropneumoniae. The identification of A. pleuropneumoniae genes, specially expressed in vivo, is a useful tool to reveal the mechanism of infection. IVIAT was used in this work to identify antigens expressed in vivo during A. pleuropneumoniae infection, using sera from individuals with chronic porcine pleuropneumonia. Sequencing of DNA inserts from positive clones showed 11 open reading frames with high homology to A. pleuropneumoniae genes. Based on sequence analysis, proteins encoded by these genes were involved in metabolism, replication, transcription regulation, and signal transduction. Moreover, three function-unknown proteins were also indentified in this work. Expression analysis using quantitative real-time PCR showed that most of the genes tested were up-regulated in vivo relative to their expression levels in vitro. IVI (in vivoinduced) genes that were amplified by PCR in different A. pleuropneumoniae strains showed that these genes could be detected in almost all of the strains. It is demonstrated that the identified IVI antigen may have important roles in the infection of A. pleuropneumoniae. PMID:26059519

  17. IgE-associated IGHV genes from venom and peanut allergic individuals lack mutational evidence of antigen selection.

    PubMed

    Wang, Yan; Jackson, Katherine J L; Davies, Janet; Chen, Zhiliang; Gaeta, Bruno A; Rimmer, Janet; Sewell, William A; Collins, Andrew M

    2014-01-01

    Antigen selection of B cells within the germinal center reaction generally leads to the accumulation of replacement mutations in the complementarity-determining regions (CDRs) of immunoglobulin genes. Studies of mutations in IgE-associated VDJ gene sequences have cast doubt on the role of antigen selection in the evolution of the human IgE response, and it may be that selection for high affinity antibodies is a feature of some but not all allergic diseases. The severity of IgE-mediated anaphylaxis is such that it could result from higher affinity IgE antibodies. We therefore investigated IGHV mutations in IgE-associated sequences derived from ten individuals with a history of anaphylactic reactions to bee or wasp venom or peanut allergens. IgG sequences, which more certainly experience antigen selection, served as a control dataset. A total of 6025 unique IgE and 5396 unique IgG sequences were generated using high throughput 454 pyrosequencing. The proportion of replacement mutations seen in the CDRs of the IgG dataset was significantly higher than that of the IgE dataset, and the IgE sequences showed little evidence of antigen selection. To exclude the possibility that 454 errors had compromised analysis, rigorous filtering of the datasets led to datasets of 90 core IgE sequences and 411 IgG sequences. These sequences were present as both forward and reverse reads, and so were most unlikely to include sequencing errors. The filtered datasets confirmed that antigen selection plays a greater role in the evolution of IgG sequences than of IgE sequences derived from the study participants. PMID:24586993

  18. Development of PCR Assays Targeting Genes in O-Antigen Gene Clusters for Detection and Identification of Escherichia coli O45 and O55 Serogroups

    PubMed Central

    DebRoy, Chitrita; Fratamico, Pina M.; Roberts, Elisabeth; Davis, Michael A.; Liu, Yanhong

    2005-01-01

    The Escherichia coli O45 O-antigen gene cluster of strain O45:H2 96-3285 was sequenced, and conventional (singleplex), multiplex, and real-time PCR assays were designed to amplify regions in the wzx (O-antigen flippase) and wzy (O-antigen polymerase) genes. In addition, PCR assays targeting the E. coli O55 wzx and wzy genes were designed based on previously published sequences. PCR assays targeting E. coli O45 showed 100% specificity for this serogroup, whereas by PCR assays specific for E. coli O55, 97/102 strains serotyped as E. coli O55 were positive for wzx and 98/102 for wzy. Multiplex PCR assays targeting the E. coli O45 and the E. coli O55 wzx and wzy genes were used to detect the organisms in fecal samples spiked at levels of 106 and 108 CFU/0.2 g feces. Thus, the PCR assays can be used to detect and identify E. coli serogroups O45 and O55. PMID:16085897

  19. Molecular cloning and sequence analysis of the Sta58 major antigen gene of Rickettsia tsutsugamushi: sequence homology and antigenic comparison of Sta58 to the 60-kilodalton family of stress proteins.

    PubMed Central

    Stover, C K; Marana, D P; Dasch, G A; Oaks, E V

    1990-01-01

    The scrub typhus 58-kilodalton (kDa) antigen (Sta58) of Rickettsia tsutsugamushi is a major protein antigen often recognized by humans infected with scrub typhus rickettsiae. A 2.9-kilobase HindIII fragment containing a complete sta58 gene was cloned in Escherichia coli and found to express the entire Sta58 antigen and a smaller protein with an apparent molecular mass of 11 kDa (Stp11). DNA sequence analysis of the 2.9-kilobase HindIII fragment revealed two adjacent open reading frames encoding proteins of 11 (Stp11) and 60 (Sta58) kDa. Comparisons of deduced amino acid sequences disclosed a high degree of homology between the R. tsutsugamushi proteins Stp11 and Sta58 and the E. coli proteins GroES and GroEL, respectively, and the family of primordial heat shock proteins designated Hsp10 Hsp60. Although the sequence homology between the Sta58 antigen and the Hsp60 protein family is striking, the Sta58 protein appeared to be antigenically distinct among a sample of other bacterial Hsp60 homologs, including the typhus group of rickettsiae. The antigenic uniqueness of the Sta58 antigen indicates that this protein may be a potentially protective antigen and a useful diagnostic reagent for scrub typhus fever. Images PMID:2108930

  20. A New O-Antigen Gene Cluster Has a Key Role in the Virulence of the Escherichia coli Meningitis Clone O45:K1:H7▿

    PubMed Central

    Plainvert, Céline; Bidet, Philippe; Peigne, Chantal; Barbe, Valérie; Médigue, Claudine; Denamur, Erick; Bingen, Edouard; Bonacorsi, Stéphane

    2007-01-01

    A new highly pathogenic clone of Escherichia coli meningitis strains harboring the unusual serogroup O45 has recently emerged in France. To gain insight into the pathogenicity of this new clone, we investigated the possible role of antigen O45 in the virulence of strain S88 (O45:K1:H7), representative of this emerging clone. We first showed that the S88 O-antigen gene cluster sequence differs from that of O45 in the reference strain E. coli 96-3285, suggesting that the two O45 polysaccharides, while probably sharing a community of epitopes, represent two different antigens. The unique functional organization of the two O-antigen gene clusters and the low DNA sequence homology of the orthologous genes suggest that the two loci originated from a common ancestor and have since undergone multiple recombination events. Phylogenetic analysis based on the flanking gene gnd sequences indicates that the S88 antigen O45 (O45S88) gene cluster may have been acquired, at least in part, from another member of the Enterobacteriaceae. Mutagenesis of the O45S88 antigen gene cluster was used for functional analysis of the loci and revealed the crucial role of the O polysaccharide in S88 virulence in a neonatal rat meningitis model. We also developed a PCR method to specifically identify the O45S88 antigen gene cluster. Together, our findings suggest that horizontal acquisition of a new O-antigen gene cluster, at least partly from another species, may have been a key event in the emergence and virulence of the E. coli O45:K1:H7 clone in France. PMID:17905975

  1. Generation of multi-functional antigen-specific human T-cells by lentiviral TCR gene transfer.

    PubMed

    Perro, M; Tsang, J; Xue, S-A; Escors, D; Cesco-Gaspere, M; Pospori, C; Gao, L; Hart, D; Collins, M; Stauss, H; Morris, E C

    2010-06-01

    T-cell receptor (TCR) gene transfer is an attractive strategy to generate antigen-specific T-cells for adoptive immunotherapy of cancer and chronic viral infection. However, current TCR gene transfer protocols trigger T-cell differentiation into terminally differentiated effector cells, which likely have reduced ability to mediate disease protection in vivo. We have developed a lentiviral gene transfer strategy to generate TCR-transduced human T-cells without promoting T-cell differentiation. We found that a combination of interleukin-15 (IL15) and IL21 facilitated lentiviral TCR gene transfer into non-proliferating T-cells. The transduced T-cells showed redirection of antigen specificity and produced IL2, IFNgamma and TNFalpha in a peptide-dependent manner. A significantly higher proportion of the IL15/IL21-stimulated T-cells were multi-functional and able to simultaneously produce all three cytokines (P<0.01), compared with TCR-transduced T-cells generated by conventional anti-CD3 plus IL2 stimulation, which primarily secreted only one cytokine. Similarly, IL15/IL21 maintained high levels of CD62L and CD28 expression in transduced T-cells, whereas anti-CD3 plus IL2 accelerated the loss of CD62L/CD28 expression. The data demonstrate that the combination of lentiviral TCR gene transfer together with IL15/IL21 stimulation can efficiently redirect the antigen specificity of resting primary human T-cells and generate multi-functional T-cells. PMID:20164855

  2. Modulation of Cellular and Viral Gene Expression by the Latency-Associated Nuclear Antigen of Kaposi's Sarcoma-Associated Herpesvirus

    PubMed Central

    Renne, Rolf; Barry, Chris; Dittmer, Dirk; Compitello, Nicole; Brown, Patrick O.; Ganem, Don

    2001-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is the likely etiological agent of Kaposi's sarcoma and primary effusion lymphoma. Common to these malignancies is that tumor cells are latently infected with KSHV. Viral gene expression is limited to a few genes, one of which is the latency-associated nuclear antigen (LANA), the product of ORF73. Examination of the primary sequence of LANA reveals some structural features reminiscent of transcription factors, leading us to hypothesize that LANA may regulate viral and cellular transcription during latency. In reporter gene-based transient transfection assays, we found that LANA can have either positive or negative effects on gene expression. While expression of a reporter gene from several synthetic promoters was increased in the presence of LANA, expression from the human immunodeficiency virus (HIV) long terminal repeat (LTR)—and from NF-κB-dependent reporter genes—was reduced by LANA expression. In addition, the promoter of KSHV ORF73 itself is activated up to 5.5-fold by LANA. This autoregulation may be important in tumorigenesis, because two other genes (v-cyclin and v-FLIP) with likely roles in cell growth and survival are also controlled by this element. To identify cellular genes influenced by LANA, we employed cDNA array-based expression profiling. Six known genes (and nine expressed sequence tags) were found to be upregulated in LANA-expressing cell lines. One of these, Staf-50, is known to inhibit expression from the HIV LTR; most of the other known genes are interferon inducible, although the interferon genes themselves were not induced by LANA. These data demonstrate that LANA expression has effects on cellular and viral gene expression. We suggest that, whether direct or indirect in origin, these effects may play important roles in the pathobiology of KSHV infection. PMID:11119614

  3. 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

  4. Structure and gene cluster of the O-antigen of Escherichia coli O156 containing a pyruvic acid acetal.

    PubMed

    Duan, Zhifeng; Senchenkova, Sof'ya N; Guo, Xi; Perepelov, Andrei V; Shashkov, Alexander S; Liu, Bin; Knirel, Yuriy A

    2016-07-22

    The lipopolysaccharide of Escherichia coli O156 was degraded under mild acidic and alkaline conditions and the resulting polysaccharides were studied by sugar analysis and (1)H and (13)C NMR spectroscopy. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established: where Rpyr indicates R-configurated pyruvic acid acetal. Minor O-acetyl groups also were present and tentatively localized on the Gal residues. The gene cluster for biosynthesis of the O-antigen of E. coli O156 was analyzed and shown to be consistent with the O-polysaccharide structure. PMID:27177202

  5. Variability of genes encoding surface proteins used as vaccine antigens in meningococcal endemic and epidemic strain panels from Norway.

    PubMed

    Holst, Johan; Comanducci, Maurizio; Bambini, Stefania; Muzzi, Alessandro; Comandi, Sara; Oksnes, Jan; DeTora, Lisa; Pizza, Mariagrazia; Rappuoli, Rino; Caugant, Dominique A

    2014-05-13

    Surface-expressed protein antigens such as factor H-binding protein (fHbp), Neisserial adhesin A (NadA), Neisserial heparin-binding antigen (NHBA) and Porin protein A (PorA); all express sequence variability that can affect their function as protective immunogens when used in meningococcal serogroup B vaccines like the recently-approved 4CMenB (Bexsero(®)). We assessed the sequence variation of genes coding for these proteins and two additional proteins ("fusion partners" to fHbp and NHBA) in pathogenic isolates from a recent low incidence period (endemic situation; 2005-2006) in Norway. Findings among strains from this panel were contrasted to what was found among isolates from a historic outbreak (epidemic situation; 1985-1990). Multilocus sequence typing revealed 14 clonal complexes (cc) among the 66 endemic strains, while cc32 vastly predominated in the 38-strain epidemic panel. Serogroup B isolates accounted for 50/66 among endemic strains and 28/38 among epidemic strains. Potential strain-coverage ("sequence match") for the 4CMenB vaccine was identified among the majority (>70%) of the endemic serogroup B isolates and all of the epidemic serogroup B isolates evaluated. Further information about the degree of expression, surface availability and the true cross-reactivity for the vaccine antigens will be needed to fully characterize the clinical strain-coverage of 4CMenB in various geographic and epidemiological situations. PMID:24631075

  6. Serological characterization and gene localization of an Escherichia coli-expressed 37-kilodalton Treponema pallidum antigen.

    PubMed Central

    Rodgers, G C; Laird, W J; Coates, S R; Mack, D H; Huston, M; Sninsky, J J

    1986-01-01

    A recombinant plasmid containing a 5.6-kilobase-pair DNA fragment of the Treponema pallidum genome was characterized by endonuclease mapping, and the encoded proteins were expressed in Escherichia coli and analyzed by use of in vitro transcription and translation. One of the proteins, identified as having a molecular weight of 37,000 (37K protein), was selected for further study. Initially, the seroreactivity of the partially purified 37K antigen was demonstrated by immunoblotting. After its purification to near homogeneity, the cloned T. pallidum protein was assessed for diagnostic significance by radioimmunoassay. Although first identified as seroreactive by screening with secondary syphilitic sera (T. E. Fehniger, A. M. Walfield, T. M. Cunningham, J. D. Radolf, J. N. Miller, and M. A. Lovett, Abstr. Annu. Meet. Am. Soc. Microbiol. 1985, B156, p. 44), the antigen was shown to be serologically reactive with antibodies in serum from all stages of syphilis but was not recognized by serum from controls by both immunoblotting and radioimmune assay. Further, a monospecific polyclonal rabbit antiserum generated to the 37K antigen recognized a polypeptide of the same molecular weight from T. pallidum but did not efficiently recognize proteins from five nonpathogenic treponemes tested. Therefore, because of reactivity with and specificity for T. pallidum antibodies, the 37K antigen may be of serodiagnostic value in the detection of syphilis. Images PMID:3522427

  7. Investigating the impact of hepatitis B virus surface gene polymorphism on antigenicity using ex vivo phenotyping.

    PubMed

    Ijaz, Samreen; Szypulska, Renata; Andrews, Nick; Tedder, Richard S

    2012-11-01

    The hepatitis B virus (HBV) surface antigen (HBsAg) is a complex protein, and understanding accurately the impact of amino acid changes on the antigenicity of the immunodominant a determinant must take this complexity into consideration. Epitope mapping with four mAbs was used to phenotype HBsAg directly from patients' sera to investigate the effect of mutations in their native genetic backbone. The expected mAb reactivity was established initially for samples harbouring 'wild-type' HBsAg sequences across genotypes A-E. The alteration of HBsAg antigenicity, defined by mAb epitope loss, was demonstrated in a number of samples with sequence-inferred amino acid changes. Individual mutations within the mapped epitopes to which the mAbs were directed usually affected their binding. However, the loss of more than one epitope was observed as the number of mutations within a sequence increased. Conversely, not all mutations occurring in the a determinant altered the HBsAg conformation. The genotype backbone, the specific amino acid substitution and amino acid changes occurring outside the major antigenic region appeared to be important in determining expression of the predicted epitope loss. These data clearly demonstrate that sequence-based methods alone may not accurately define HBsAg phenotype. This phenotyping methodology allows for the rapid and accurate identification of antigenically altered viruses and will greatly enhance current HBV surveillance, research and diagnostic activities. The data generated can be used to inform on public health issues relating to prevalence, transmission and impact of HBsAg mutants in HBV-infected populations. PMID:22855781

  8. Oral Administration of Lactococcus lactis Expressing Synthetic Genes of Myelin Antigens in Decreasing Experimental Autoimmune Encephalomyelitis in Rats

    PubMed Central

    Kasarello, Kaja; Kwiatkowska-Patzer, Barbara; Lipkowski, Andrzej W.; Bardowski, Jacek K.; Szczepankowska, Agnieszka K.

    2015-01-01

    Background Multiple sclerosis is a human autoimmunological disease that causes neurodegeneration. One of the potential ways to stop its development is induction of oral tolerance, whose effect lies in decreasing immune response to the fed antigen. It was shown in animal models that administration of specific epitopes of the three main myelin proteins – myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), and proteolipid protein (PLP) – results in induction of oral tolerance and suppression of disease symptoms. Use of bacterial cells to produce and deliver antigens to gut mucosa seems to be an attractive method for oral tolerance induction in treatment of diseases with autoimmune background. Material/Methods Synthetic genes of MOG35-55, MBP85-97, and PLP139-151 myelin epitopes were generated and cloned in Lactococcus lactis under a CcpA-regulated promoter. The tolerogenic effect of bacterial preparations was tested on experimental autoimmune encephalomyelitis, which is the animal model of MS. EAE was induced in rats by intradermal injection of guinea pig spinal cord homogenate into hind paws. Results Rats were administered preparations containing whole-cell lysates of L. lactis producing myelin antigens using different feeding schemes. Our study demonstrates that 20-fold, but not 4-fold, intragastric administration of autoantigen-expressing L. lactis cells under specific conditions reduces the clinical symptoms of EAE in rats. Conclusions The present study evaluated the use of myelin antigens produced in L. lactis in inhibiting the onset of experimental autoimmune encephalomyelitis in rats. Obtained results indicate that application of such recombinant cells can be an attractive method of oral tolerance induction. PMID:26026273

  9. Surface antigen expression and correlation with variable heavy-chain gene mutation status in chronic lymphocytic leukemia.

    PubMed

    Vilpo, Juhani; Tobin, Gerard; Hulkkonen, Janne; Hurme, Mikko; Thunberg, Ulf; Sundström, Christer; Vilpo, Leena; Rosenquist, Richard

    2003-01-01

    Recent studies have demonstrated that B-cell chronic lymphocytic leukemia (CLL) consists of two clinical entities with either somatically hypermutated (M-CLL) or unmutated (UM-CLL) immunoglobulin variable heavy-chain (VH) regions. In view of the fact that the cellular biology of these two subsets of disease is currently unexplored, we performed an extensive analysis of the surface antigen expression and correlated this with the VH gene mutation status in a cohort of 32 CLL patients. Using polymerase chain reaction amplification and nucleotide sequencing, the VH genes were shown to be mutated in 10 cases (31%) and unmutated in 22 (69%). The expression of 27 surface membrane antigens in peripheral blood leukemic cells was analyzed by flow cytometry, measuring both the percentage of positive cells as well as the geometric mean fluorescence intensity (GMF). Most of the surface membrane antigens (CD5, CD11c, CD19, CD20, CD21, CD22, CD23, CD25, CD40, CD45, VD79b, CD80, CD95, CD122, CD124, CD126, CD130, CD154, IgM, and IgD) showed a similar expression pattern in both UM-CLL and M-CLL patients. The similarity of M-CLL and UM-CLL, as demonstrated here for the first time with many protein markers, indicates a considerably homogeneous phenotype in both subsets. Furthermore, CD27 was strongly expressed in all cases, which may suggest a memory cell phenotype for both M-CLL and UM-CLL. More positive cells in the UM-CLL group were observed regarding CD38, but CD38 was not a good predictor of VH gene mutation status. Seventy percent of the M-CLL cases, but only 36% of UM-CLL cases, were Ig-lambda+. The most striking differential expression, however, was observed in the two slicing variants of the common leukocyte antigen CD45, namely CD45RO and CD45RA. CD45RO expression was significantly associated with M-CLL, whereas the GMF intensity of CD45RA tended to be associated with UM-CLL. The role of these CD45 splicing variants in the pathogenesis of CLL deserves further investigation

  10. Identification of genes expressed during Toxoplasma gondii infection by in vivo-induced antigen technology (IVIAT) with positive porcine sera.

    PubMed

    Tao, Qing; Xiao, Jiang; Wang, Yifan; Fang, Kun; Li, Nizhi; Hu, Min; Zhou, Yanqin; Zhao, Junlong

    2014-08-01

    Infection of pigs with Toxoplasma gondii is a common source of human toxoplasmosis and causes serious economic losses. In vivo-induced antigen technology (IVIAT) is an effective immunological technique to identify the antigens that a pathogen specifically expressed during infection. To discover the genes that are important in T. gondii infection of pigs, we employed IVIAT using sera from infected pigs. Fourteen antigens were identified including microneme protein 11 (MIC11), dense granule protein 5 (GRA5), 18 kDa cyclophilin (C-18), serine proteinase inhibitor (PI), calmodulin (CaM), leucine-rich repeat protein ( LRRP), D-3-phosphoglycerate dehydrogenase (D3PD), elongation factor 1-gamma (EF1), and 6 hypothetical proteins. The increased transcription levels of 5 (MIC11, GRA5, C-18, PI, and CaM) of the 14 molecules identified by IVIAT were confirmed by real-time PCR. The full length or partial proteins encoded by these 5 genes were expressed in Escherichia coli , and their immunogenicity was confirmed by Western blot analysis with positive porcine sera. Further functional studies were conducted with CaM. Suppression of CaM expression by RNA interference decreased T. gondii tachyzoites cell attachment, invasion, and egress but did not influence their replication. The proteins identified in this study are predicted to be involved in cell invasion, ion-protein binding, protein folding, biosynthesis, and metabolism. The results of the functional analysis support the hypothesis that CaM contributes to parasite pathogenesis during infection. These results may have significant implications for the discovery of candidate molecules for the development of potential therapies and preventive measures against toxoplasmosis in pigs. PMID:24646180

  11. The human application of gene therapy to re-program T-cell specificity using chimeric antigen receptors

    PubMed Central

    Guerrero, Alan D; Moyes, Judy S; Cooper, Laurence JN

    2014-01-01

    The adoptive transfer of T cells is a promising approach to treat cancers. Primary human T cells can be modified using viral and non-viral vectors to promote the specific targeting of cancer cells via the introduction of exogenous T-cell receptors (TCRs) or chimeric antigen receptors (CARs). This gene transfer displays the potential to increase the specificity and potency of the anticancer response while decreasing the systemic adverse effects that arise from conventional treatments that target both cancerous and healthy cells. This review highlights the generation of clinical-grade T cells expressing CARs for immunotherapy, the use of these cells to target B-cell malignancies and, particularly, the first clinical trials deploying the Sleeping Beauty gene transfer system, which engineers T cells to target CD19+ leukemia and non-Hodgkin's lymphoma. PMID:25189715

  12. Escherichia coli serogroup O2 and O28ac O-antigen gene cluster sequences and detection of pathogenic E. coli O2 and O28ac by PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The O antigen gene clusters of Escherichia coli serogroups O2 and O28ac were sequenced. Thirteen open reading frames (ORFs) were identified in the O antigen gene cluster of E. coli O2 strain O2:H4 U 9-41, and 7 ORFs were identified in the O antigen gene cluster of E. coli serogroup O28ac strain O2...

  13. Specific Colon Cancer Cell Cytotoxicity Induced by Bacteriophage E Gene Expression under Transcriptional Control of Carcinoembryonic Antigen Promoter

    PubMed Central

    Rama, Ana R.; Hernandez, Rosa; Perazzoli, Gloria; Burgos, Miguel; Melguizo, Consolación; Vélez, Celia; Prados, Jose

    2015-01-01

    Colorectal cancer is one of the most prevalent cancers in the world. Patients in advanced stages often develop metastases that require chemotherapy and usually show a poor response, have a low survival rate and develop considerable toxicity with adverse symptoms. Gene therapy may act as an adjuvant therapy in attempts to destroy the tumor without affecting normal host tissue. The bacteriophage E gene has demonstrated significant antitumor activity in several cancers, but without any tumor-specific activity. The use of tumor-specific promoters may help to direct the expression of therapeutic genes so they act against specific cancer cells. We used the carcinoembryonic antigen promoter (CEA) to direct E gene expression (pCEA-E) towards colon cancer cells. pCEA-E induced a high cell growth inhibition of human HTC-116 colon adenocarcinoma and mouse MC-38 colon cancer cells in comparison to normal human CCD18co colon cells, which have practically undetectable levels of CEA. In addition, in vivo analyses of mice bearing tumors induced using MC-38 cells showed a significant decrease in tumor volume after pCEA-E treatment and a low level of Ki-67 in relation to untreated tumors. These results suggest that the CEA promoter is an excellent candidate for directing E gene expression specifically toward colon cancer cells. PMID:26053394

  14. 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

  15. Low Levels of Polymorphisms and No Evidence for Diversifying Selection on the Plasmodium knowlesi Apical Membrane Antigen 1 Gene

    PubMed Central

    Faber, Bart W.; Abdul Kadir, Khamisah; Rodriguez-Garcia, Roberto; Remarque, Edmond J; Saul, Frederick A.; Vulliez-Le Normand, Brigitte; Bentley, Graham A.; Kocken, Clemens H. M.; Singh, Balbir

    2015-01-01

    Infection with Plasmodium knowlesi, a zoonotic primate malaria, is a growing human health problem in Southeast Asia. P. knowlesi is being used in malaria vaccine studies, and a number of proteins are being considered as candidate malaria vaccine antigens, including the Apical Membrane Antigen 1 (AMA1). In order to determine genetic diversity of the ama1 gene and to identify epitopes of AMA1 under strongest immune selection, the ama1 gene of 52 P. knowlesi isolates derived from human infections was sequenced. Sequence analysis of isolates from two geographically isolated regions in Sarawak showed that polymorphism in the protein is low compared to that of AMA1 of the major human malaria parasites, P. falciparum and P. vivax. Although the number of haplotypes was 27, the frequency of mutations at the majority of the polymorphic positions was low, and only six positions had a variance frequency higher than 10%. Only two positions had more than one alternative amino acid. Interestingly, three of the high-frequency polymorphic sites correspond to invariant sites in PfAMA1 or PvAMA1. Statistically significant differences in the quantity of three of the six high frequency mutations were observed between the two regions. These analyses suggest that the pkama1 gene is not under balancing selection, as observed for pfama1 and pvama1, and that the PkAMA1 protein is not a primary target for protective humoral immune responses in their reservoir macaque hosts, unlike PfAMA1 and PvAMA1 in humans. The low level of polymorphism justifies the development of a single allele PkAMA1-based vaccine. PMID:25881166

  16. Expression of T cell antigen receptor genes in the thymus of irradiated mice after bone marrow transplantation

    SciTech Connect

    Matsuzaki, G.; Yoshikai, Y.; Kishihara, K.; Nomoto, K.

    1988-01-15

    Sequential appearance of the expression of T cell antigen receptor genes was investigated in the thymus of irradiated mice at the early stage after transplantation of Thy-1 congeneic H-2 compatible allogeneic bone marrow cells. The first cells to repopulate the thymus on day 7 after bone marrow transplantation were intrathymic radioresistant T cell precursors, which expanded mainly to CD4+CD8+ host-type thymocytes by day 14. A high level of gamma gene expression but a much reduced level of alpha and beta gene expression were detected in the host-type thymocytes on day 7. During regeneration of these cells, gamma-chain messages fell to low level and alpha and beta mRNA levels increased. The thymus of the recipients began to be repopulated by donor-derived T cells about 2 wk after bone marrow transplantation and was almost completely replaced by the third week. An ordered expression of gamma then beta and alpha-chain gene transcript was also observed in the donor-type thymocytes at the early stage after bone marrow transplantation. The use of thymocytes at early stage in whole-body irradiated bone marrow chimera provides a pertinent source for investigating the molecular mechanism of T cell differentiation in adult thymus.

  17. A BTP1 prophage gene present in invasive non-typhoidal Salmonella determines composition and length of the O-antigen of the lipopolysaccharide

    PubMed Central

    Kintz, Erica; Davies, Mark R; Hammarlöf, Disa L; Canals, Rocío; Hinton, Jay C D; van der Woude, Marjan W

    2015-01-01

    Salmonella Typhimurium isolate D23580 represents a recently identified ST313 lineage of invasive non-typhoidal Salmonellae (iNTS). One of the differences between this lineage and other non-iNTS S. Typhimurium isolates is the presence of prophage BTP1. This prophage encodes a gtrC gene, implicated in O-antigen modification. GtrCBTP1 is essential for maintaining O-antigen length in isolate D23580, since a gtrBTP1 mutant yields a short O-antigen. This phenotype can be complemented by gtrCBTP1 or very closely related gtrC genes. The short O-antigen of the gtrBTP1 mutant was also compensated by deletion of the BTP1 phage tailspike gene in the D23580 chromosome. This tailspike protein has a putative endorhamnosidase domain and thus may mediate O-antigen cleavage. Expression of the gtrCBTP1 gene is, in contrast to expression of many other gtr operons, not subject to phase variation and transcriptional analysis suggests that gtrC is produced under a variety of conditions. Additionally, GtrCBTP1 expression is necessary and sufficient to provide protection against BTP1 phage infection of an otherwise susceptible strain. These data are consistent with a model in which GtrCBTP1 mediates modification of the BTP1 phage O-antigen receptor in lysogenic D23580, and thereby prevents superinfection by itself and other phage that uses the same O-antigen co-receptor. PMID:25586744

  18. A BTP1 prophage gene present in invasive non-typhoidal Salmonella determines composition and length of the O-antigen of the lipopolysaccharide.

    PubMed

    Kintz, Erica; Davies, Mark R; Hammarlöf, Disa L; Canals, Rocío; Hinton, Jay C D; van der Woude, Marjan W

    2015-04-01

    Salmonella Typhimurium isolate D23580 represents a recently identified ST313 lineage of invasive non-typhoidal Salmonellae (iNTS). One of the differences between this lineage and other non-iNTS S. Typhimurium isolates is the presence of prophage BTP1. This prophage encodes a gtrC gene, implicated in O-antigen modification. GtrC(BTP) (1) is essential for maintaining O-antigen length in isolate D23580, since a gtr(BTP) (1) mutant yields a short O-antigen. This phenotype can be complemented by gtrC(BTP) (1) or very closely related gtrC genes. The short O-antigen of the gtr(BTP) (1) mutant was also compensated by deletion of the BTP1 phage tailspike gene in the D23580 chromosome. This tailspike protein has a putative endorhamnosidase domain and thus may mediate O-antigen cleavage. Expression of the gtrC(BTP) (1) gene is, in contrast to expression of many other gtr operons, not subject to phase variation and transcriptional analysis suggests that gtrC is produced under a variety of conditions. Additionally, GtrC(BTP) (1) expression is necessary and sufficient to provide protection against BTP1 phage infection of an otherwise susceptible strain. These data are consistent with a model in which GtrC(BTP) (1) mediates modification of the BTP1 phage O-antigen receptor in lysogenic D23580, and thereby prevents superinfection by itself and other phage that uses the same O-antigen co-receptor. PMID:25586744

  19. 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

  20. Differentiation of Salmonella phase 1 flagellar antigen types by restriction of the amplified fliC gene.

    PubMed Central

    Kilger, G; Grimont, P A

    1993-01-01

    The large antigenic diversity (over 2,300 serotypes) expressed by Salmonella strains can probably be observed at the genetic level. The phase 1 flagellin gene fliC was amplified, and the amplified fragment was cleaved with a mixture of both endonucleases TaqI and ScaI. The restriction patterns observed allowed differentiation of flagellar types b, i, d, j, l,v, and z10. Flagellar group g (g,m, g,p, or g,m,s) could be differentiated from the other flagellar types. Flagellar types r and e,h could not be separated, although they could be distinguished from the other flagellar types studied. Practical applications of flagellar gene restriction are the distinction between serotype Gallinarum-Pullorum, which carries a cryptic gene for flagellar type g,m, and nonmotile Vi-negative variants of serotype Typhi, and the tentative assignation of nonmotile variants of Salmonella serotypes to a flagellar type. Images PMID:8388886

  1. Sequential appearance of thymocyte subpopulations and T cell antigen receptor gene messages in the mouse thymus after sublethal irradiation

    SciTech Connect

    Tomooka, S.; Matsuzaki, G.; Kishihara, K.; Tanaka, K.; Yoshikai, Y.; Taniguchi, K.; Himeno, K.; Nomoto, K.

    1987-12-15

    The sequential differentiation patterns of thymocyte were observed with cell surface phenotypes and the expression of T cell antigen receptor in 800 rad irradiated adult mice. Thymus was severely reduced in size and cell number by day 5 after whole body irradiation and rapidly recovered from day 7 to day 14. Surface marker analysis on day 5 after irradiation showed thymocytes with Thy-1low L3T4+/Lyt-2- dominantly existed and suggested that these cells were radioresistant-survived cells. On the other hand, thymocytes on day 7 were composed of a large number of Thy-1high L3T4+/Lyt-2+ blast-like cells and a relatively high proportion of Thy-1high L3T4-/Lyt-2- cells which expressed a large amount of gamma-chain gene messages but scarcely any alpha- and beta-chain gene messages similar to the fetal thymocytes. On day 14, thymocytes were composed mostly of Thy-1high H-2low L3T4+/Lyt-2+ subpopulation which expressed a remarkably low level of gamma-chain gene messages, and high levels of alpha- and beta-chain transcripts analogous to those of normal adult thymus. Taken together, intrathymic radioresistent stem cells for T thymocytes seem to proliferate and differentiate after irradiation with the same pattern as was seen in a fetal thymus development.

  2. Gene cloning, expression and immunogenicity of the protective antigen subolesin in Dermacentor silvarum.

    PubMed

    Hu, Yonghong; Zeng, Hua; Zhang, Jincheng; Wang, Duo; Li, Dongming; Zhang, Tiantian; Yang, Shujie; Liu, Jingze

    2014-02-01

    Subolesin (4D8), the ortholog of insect akirins, is a highly conserved protective antigen and thus has the potential for development of a broad-spectrum vaccine against ticks and mosquitoes. To date, no protective antigens have been characterized nor tested as candidate vaccines against Dermacentor silvarum bites and transmission of associated pathogens. In this study, we cloned the open reading frame (ORF) of D. silvarum 4D8 cDNA (Ds4D8), which consisted of 498 bp encoding 165 amino acid residues. The results of sequence alignments and phylogenetic analysis demonstrated that D. silvarum 4D8 (Ds4D8) is highly conserved showing more than 81% identity of amino acid sequences with those of other hard ticks. Additionally, Ds4D8 containing restriction sites was ligated into the pET-32(a+) expression vector and the recombinant plasmid was transformed into Escherichia coli rosetta. The recombinant Ds4D8 (rDs4D8) was induced by isopropyl β-D-thiogalactopyranoside (IPTG) and purified using Ni affinity chromatography. The SDS-PAGE results showed that the molecular weight of rDs4D8 was 40 kDa, which was consistent with the expected molecular mass considering 22 kDa histidine-tagged thioredoxin (TRX) protein from the expression vector. Western blot results showed that rabbit anti-D. silvarum serum recognized the expressed rDs4D8, suggesting an immune response against rDs4D8. These results provided the basis for developing a candidate vaccine against D. silvarum ticks and transmission of associated pathogens. PMID:24623890

  3. Gene Cloning, Expression and Immunogenicity of the Protective Antigen Subolesin in Dermacentor silvarum

    PubMed Central

    Hu, Yonghong; Zeng, Hua; Zhang, Jincheng; Wang, Duo; Li, Dongming; Zhang, Tiantian; Yang, Shujie

    2014-01-01

    Subolesin (4D8), the ortholog of insect akirins, is a highly conserved protective antigen and thus has the potential for development of a broad-spectrum vaccine against ticks and mosquitoes. To date, no protective antigens have been characterized nor tested as candidate vaccines against Dermacentor silvarum bites and transmission of associated pathogens. In this study, we cloned the open reading frame (ORF) of D. silvarum 4D8 cDNA (Ds4D8), which consisted of 498 bp encoding 165 amino acid residues. The results of sequence alignments and phylogenetic analysis demonstrated that D. silvarum 4D8 (Ds4D8) is highly conserved showing more than 81% identity of amino acid sequences with those of other hard ticks. Additionally, Ds4D8 containing restriction sites was ligated into the pET-32(a+) expression vector and the recombinant plasmid was transformed into Escherichia coli rosetta. The recombinant Ds4D8 (rDs4D8) was induced by isopropyl β-D-thiogalactopyranoside (IPTG) and purified using Ni affinity chromatography. The SDS-PAGE results showed that the molecular weight of rDs4D8 was 40 kDa, which was consistent with the expected molecular mass considering 22 kDa histidine-tagged thioredoxin (TRX) protein from the expression vector. Western blot results showed that rabbit anti-D. silvarum serum recognized the expressed rDs4D8, suggesting an immune response against rDs4D8. These results provided the basis for developing a candidate vaccine against D. silvarum ticks and transmission of associated pathogens. PMID:24623890

  4. Escherichia coli O-antigen gene clusters of serogroups O62, O68, O131, O140, O142, and O163: DNA sequences and similarity between O62 and O68, and PCR-based serogrouping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The DNA sequences of the O-antigen gene clusters of the Escherichia coli serogroups O62, O131, O140, O142 and O163 were determined. There were 9-14 open reading frames (ORFs) identified, encoding genes required for O-antigen sugar biosynthesis, transfer, and processing. Primers based on the wzx (O...

  5. DNA sequence and analysis of the O-antigen gene clusters of Escherichia coli serogroups O62, O68, O131, O140, O142, and O163 and serogroup-specific PCR assays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The DNA sequence of the O-antigen gene clusters of Escherichia coli serogroups O62, O68, O131, O140, O142, and O163 was determined. There were 9 to 12 open reading frames (ORFs) identified, encoding genes required for O-antigen sugar biosynthesis, transfer, and processing. Primers based on the wzx...

  6. Chlamydial gene encoding a 70-kilodalton antigen in Escherichia coli: analysis of expression signals and identification of the gene product.

    PubMed Central

    Sardinia, L M; Engel, J N; Ganem, D

    1989-01-01

    In an attempt to identify chlamydial genes whose native promoters allow them to be expressed in Escherichia coli, we isolated and characterized a chlamydial gene identified by screening a library of chlamydial DNA with antichlamydial antibodies. This gene encodes a 70-kilodalton immunoreactive polypeptide in E. coli hosts. Sequence analysis of the 5' portion of the gene identified its product as the chlamydial homolog of the E. coli ribosomal protein S1. The site of transcription initiation of the mRNA in chlamydiae was determined, and its putative promoter regions were identified. These regions apparently do not function efficiently in E. coli; in vitro transcripts generated by using E. coli RNA polymerase did not start at the authentic chlamydial initiation site. Several in vitro transcripts both larger and smaller than the authentic transcript were seen; presumably, these transcripts result from adventitious promoterlike elements in adjacent chlamydial DNA and may be responsible for the expression of the gene in E. coli. Images PMID:2644193

  7. 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

  8. Targeted gene delivery to the synovial pannus in antigen-induced arthritis by ultrasound-targeted microbubble destruction in vivo.

    PubMed

    Xiang, Xi; Tang, Yuanjiao; Leng, Qianying; Zhang, Lingyan; Qiu, Li

    2016-02-01

    The purpose of this study was to optimize an ultrasound-targeted microbubble destruction (UTMD) technique to improve the in vivo transfection efficiency of the gene encoding enhanced green fluorescent protein (EGFP) in the synovial pannus in an antigen-induced arthritis rabbit model. A mixture of microbubbles and plasmids was locally injected into the knee joints of an antigen-induced arthritis (AIA) rabbits. The plasmid concentrations and ultrasound conditions were varied in the experiments. We also tested local articular and intravenous injections. The rabbits were divided into five groups: (1) ultrasound+microbubbles+plasmid; (2) ultrasound+plasmid; (3) microbubble+plasmid; (4) plasmid only; (5) untreated controls. EGFP expression was observed by fluorescent microscope and immunohistochemical staining in the synovial pannus of each group. The optimal plasmid dosage and ultrasound parameter were determined based on the results of EGFP expression and the present and absent of tissue damage under light microscopy. The irradiation procedure was performed to observe the duration of the EGFP expression in the synovial pannus and other tissues and organs, as well as the damage to the normal cells. The optimal condition was determined to be a 1-MHz ultrasound pulse applied for 5 min with a power output of 2 W/cm(2) and a 20% duty cycle along with 300 μg of plasmid. Under these conditions, the synovial pannus showed significant EGFP expression without significant damage to the surrounding normal tissue. The EGFP expression induced by the local intra-articular injection was significantly more increased than that induced by the intravenous injection. The EGFP expression in the synovial pannus of the ultrasound+microbubbles+plasmid group was significantly higher than that of the other four groups (P<0.05). The expression peaked on day 5, remained detectable on day 40 and disappeared on day 60. No EGFP expression was detected in the other tissues and organs. The UTMD

  9. Physical mapping of the human T-cell antigen receptor (TCR) {beta}-chain gene complex

    SciTech Connect

    Yashim, Y.; So, A.K.

    1994-09-01

    The genetic variation of the TCR loci and their contribution to autoimmune diseases is poorly defined, in direct contrast to the clear examples of disease association with the Class I and II alleles of the major histocompatibility complex. We have therefore started to determine the gene organization and polymorphism of the TCR {beta} locus. Yeast artificial chromosomes (YACs) were used to construct a physical map of the germline human TCR {beta}-chain gene complex. Variable gene (V{beta}) sequences for the 25 known V{beta} subfamilies were amplified by PCR and were used as probes to screen a YAC library. Five positive YACs were identified. YACs designated B3, E11 and H11 of sizes 820, 400 and 600 kbp, respectively, were analyzed for their V{beta} content by pulse-field gel electrophoresis (PFGE). YAC B3 was found to contain all 25 V{beta} subfamilies, E11 for 14 and H11 for 7. B3 was also positive for the constant region genes. Restriction enzyme mapping of B3 located V{beta} and C{beta} gene regions to four Sfi I fragments of 280, 110, 90 and 125 kbp, and was in accordance with published data. The data thus showed that YAC B3 encoded a complete and unrearranged TCR {beta}-gene locus. The map was further resolved by locating restriction sites for Sal I and Bssll II on B3. Fluorescent in situ hybridization to human metaphase chromosomes localized B3 to chromosome 7q35. However, two additional signals were obtained: one attributable to V{beta} orphon cluster on chromosome 9q21; the second to the long arm of chromosome 2. PCR amplification of a chromosome 2 somatic cell hybrid using primers for all 25 V{beta} gene families revealed the signal was not attributable to a second orphon cluster. It is suggested that B3 is a chimeric YAC with an intact TCR {beta} locus flanked by chromosome 2 sequences. The determination of the TCR genomic organization will help extend studies of the role T-cells play in autoimmune diseases.

  10. Relationship between target antigens and major histocompatibility complex (MHC) class II genes in producing two pathogenic antibodies simultaneously

    PubMed Central

    Zakka, L R; Keskin, D B; Reche, P; Ahmed, A R

    2010-01-01

    In this report, we present 15 patients with histological and immunopathologically proven pemphigus vulgaris (PV). After a mean of 80 months since the onset of disease, when evaluated serologically, they had antibodies typical of PV and pemphigoid (Pg). Similarly, 18 patients with bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP) were diagnosed on the basis of histology and immunopathology. After a mean of 60 months since the onset of disease, when their sera were evaluated they were found to have Pg and PV autoantibodies. In both groups of patients the diseases were characterized by a chronic course, which included several relapses and recurrences and were non-responsive to conventional therapy. The major histocompatibility complex class II (MHC II) genes were studied in both groups of patients and phenotypes associated typically with them were observed. Hence, in 33 patients, two different pathogenic autoantibodies were detected simultaneously. The authors provide a computer model to show that each MHC II gene has relevant epitopes that recognize the antigens associated with both diseases. Using the databases in these computer models, the authors present the hypothesis that these two autoantibodies are produced simultaneously due to the phenomena of epitope spreading. PMID:21069937

  11. Identification and mapping of Epstein-Barr virus early antigens and demonstration of a viral gene activator that functions in trans.

    PubMed Central

    Wong, K M; Levine, A J

    1986-01-01

    The BamHI M DNA fragment of the Epstein-Barr virus (EBV) genome was inserted in two orientations into a simian virus 40-based expression vector, and the EBV-specific proteins produced in COS-7 monkey cells were examined. In one orientation, termed BamHI-M rightward reading frame 1 (BMRF1), a set of phosphoproteins ranging in size from 47,000 to 54,000 daltons was synthesized. These proteins reacted with monoclonal and polyclonal antisera, defining them as components of the EBV early antigen diffuse set of proteins (EA-D). The BamHI M DNA fragment in the opposite orientation, termed BamHI-M leftward reading frame 1 (BMLF1), directed the synthesis of a nuclear antigen detected by antibodies in serum from a patient with nasopharyngeal carcinoma. The BMLF1 antigen was not detected by monoclonal or polyclonal antibodies directed against the EA-D complex. A series of deletion mutants were constructed in the BamHI M DNA fragment, and the EA-D complex and BMLF1 antigen were mapped to discrete open reading frames in this DNA fragment. A test for several possible functions of these antigens showed that the BMLF1 antigen had the ability to activate or enhance, in trans, the level of expression of a gene under the control of the adenovirus early region 3 promoter or the simian virus 40 early promoter in the absence of its cis-acting enhancer. These experiments demonstrate a new gene function, encoded by EBV, that may be important in the positive regulation of viral or cellular genes. Images PMID:3018282

  12. Structural comparison of O-antigen gene clusters of Legionella pneumophila and its application of a serogroup-specific multiplex PCR assay.

    PubMed

    Cao, Boyang; Tian, Zhenyang; Wang, Suwei; Zhu, Zhiyan; Sun, Yamin; Feng, Lu; Wang, Lei

    2015-12-01

    The Legionella pneumophila serogroups O1, O4, O6, O7, O10 and O13 are pathogenic strains associated with pneumonia. The surface O-antigen gene clusters of L. pneumophila serogroups O4, O6, O7, O10 and O13 were sequenced and analyzed, with the function annotated on the basis of homology to that of the genes of L. pneumophila serogroup O1 (L. pneumophila subsp. pneumophila str. Philadelphia 1). The gene locus of the six L. pneumophila serogroups contains genes of yvfE, neuABCD, pseA-like for nucleotide sugar biosynthesis, wecA for sugar transfer, and wzm as well as wzt for O-antigen processing. The detection of O-antigen genes allows the fine differentiation at species and serogroup level without the neccessity of nucleotide sequencing. The O-antigen-processing genes wzm and wzt, which were found to be distinctive for different for different serogroups, have been used as the target genes for the detection and identification of L. pneumophila strains of different O serogroups. In this report, a multiplex PCR assay based on wzm or wzt that diferentiates all the six serogroups by amplicon size was developed with the newly designed specific primer pairs for O1 and O7, and the specific primer pairs for O4, O6, O10, and O13 reported previously. The array was validated by analysis of 34 strains including 15 L. pneumophila O-standard reference strains, eight reference strains of other Legionella non-pneumophila species, six other bacterial species, and five L. pneumophila environmental isolates. The detection sensitivity was one ng genomic DNA. The accurate and sensitive assay is suitable for the identification and detection of strains of these serogroups in environmental and clinical samples. PMID:26415652

  13. Radioimmunolocalisation in breast cancer using the gene product of c-erbB2 as the target antigen.

    PubMed Central

    Allan, S. M.; Dean, C.; Fernando, I.; Eccles, S.; Styles, J.; McCready, V. R.; Baum, M.; Sacks, N.

    1993-01-01

    Lymph node status is still the single most important prognostic factor in breast cancer. Axillary surgery remains the only reliable means of providing this information. This pilot study evaluates using a highly specific radiolabelled monoclonal antibody to provide equivalent information by a non-invasive technique. After optimisation of labelling conditions, our first antibody, ICR12 (against the gene product of c-erbB-2) was evaluated in a mouse model system. Twenty-four hours post i.v. injection the mice were killed and their organs, blood and tumours harvested for counting. Tumour localisation was four times greater than that into normal tissues, reaching 20% injected dose per gram of tumour. Eight patients have had this Tc99m-ICR12. Patient selection was by immunocytochemical staining of fine needle aspirates from the patient's own breast cancer. After intravenous administration of the immunoconjugate, tomographic images were obtained at 24 h. These results were compared to the subsequent histopathological examinations. Three patients acted as normal controls, one patient was negative due to inappropriate sampling, and two patients had strong membrane staining and provided excellent tumour localisation to both breast primary and regional node metastases. A further two patients only had moderate antigen expression on staining and did not localise well. The good performance of this radiolabelled antibody with patients that strongly stain for the antigen encourages the development of this system as both a method of staging breast cancer and a potential means of immunotherapy in this subgroup of patients. Images Figure 1 Figure 3 Figure 5 Figure 6 Figure 7 PMID:8097104

  14. 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

  15. p53 gene product expression in resected non-small cell carcinoma of the lung, with studies of concurrent cytological preparations and microwave antigen retrieval.

    PubMed Central

    Binks, S; Clelland, C A; Ronan, J; Bell, J

    1997-01-01

    AIM: To document the frequency and extent of p53 gene product expression in paraffin sections of resected non-small cell carcinoma of the lung and in cytological preparations of the same tumours; to determine the effect of microwave antigen retrieval on antigen detection. METHODS: Representative paraffin sections of 50 non-small cell carcinomas were stained with an antibody to p53 gene product (DO-7) both with and without prior microwave antigen retrieval. Cytoblocks and cell smears obtained from 19 cases were similarly stained. RESULTS: Using a histochemical scoring system (0-300) which takes into account staining intensity and extent, 78% (n = 39) of microwave pretreated paraffin sections and 52% (n = 26) of non-pretreated sections scored between 5 and 300; p = 0.001; 56% (n = 28) of microwave pretreated sections and only 2% (n = 1) of non-pretreated sections scored between 100 and 300 (p = 0.0001); 75% of direct smears of tumours and 80% of cytoblocks stained similarly to the paraffin sections of the resected specimens. No smears or cytoblocks stained positively when the sections of the resected specimen were negative. CONCLUSIONS: As up to 78% of non-small cell lung carcinomas overexpress p53 gene product, this may prove to be a valuable diagnostic method in biopsy or cytological material when the morphological diagnosis is uncertain. Microwave antigen retrieval is effective on formalin fixed tissue. Images PMID:9215149

  16. Antigen-presenting genes and genomic copy number variations in the Tasmanian devil MHC

    PubMed Central

    2012-01-01

    Background The Tasmanian devil (Sarcophilus harrisii) is currently under threat of extinction due to an unusual fatal contagious cancer called Devil Facial Tumour Disease (DFTD). DFTD is caused by a clonal tumour cell line that is transmitted between unrelated individuals as an allograft without triggering immune rejection due to low levels of Major Histocompatibility Complex (MHC) diversity in Tasmanian devils. Results Here we report the characterization of the genomic regions encompassing MHC Class I and Class II genes in the Tasmanian devil. Four genomic regions approximately 960 kb in length were assembled and annotated using BAC contigs and physically mapped to devil Chromosome 4q. 34 genes and pseudogenes were identified, including five Class I and four Class II loci. Interestingly, when two haplotypes from two individuals were compared, three genomic copy number variants with sizes ranging from 1.6 to 17 kb were observed within the classical Class I gene region. One deletion is particularly important as it turns a Class Ia gene into a pseudogene in one of the haplotypes. This deletion explains the previously observed variation in the Class I allelic number between individuals. The frequency of this deletion is highest in the northwestern devil population and lowest in southeastern areas. Conclusions The third sequenced marsupial MHC provides insights into the evolution of this dynamic genomic region among the diverse marsupial species. The two sequenced devil MHC haplotypes revealed three copy number variations that are likely to significantly affect immune response and suggest that future work should focus on the role of copy number variations in disease susceptibility in this species. PMID:22404855

  17. Celastrus treatment modulates antigen-induced gene expression in lymphoid cells of arthritic rats.

    PubMed

    Yu, H; Venkatesha, S H; Nanjundaiah, S; Tong, L; Moudgil, K D

    2012-01-01

    Rheumatoid arthritis (RA) is a debilitating autoimmune disease of global prevalence and the disease process primarily targets the synovial joints. Despite improvements in the treatment of RA over the past decade, there still is a need for new therapeutic agents that are efficacious, less expensive, and free of severe adverse reactions. Celastrus has been used in China for centuries for the treatment of rheumatic diseases. Furthermore, we previously reported that ethanol extract of Celastrus aculeatus Merr. (Celastrus) attenuates adjuvant-induced arthritis (AA) in rats. However, the mechanisms underlying the anti-arthritic activity of Celastrus have not yet been fully defined. We reasoned that microarray analysis might offer useful insights into the pathways and molecules targeted by Celastrus. We compared the gene expression profiles of the draining lymph node cells (LNC) of Celastrus-treated (Tc) versus water-treated (Tw) rats, and each group with untreated arthritic rats (T(0)). LNC were restimulated with mycobacterial heat shock protein-65 (Bhsp65). We identified 104 differentially expressed genes (DEG) (8 upregulated, 96 downregulated) when comparing Tc with T(0) rats, in contrast to 28 (12 upregulated, 16 downregulated) when comparing Tw and T(0) rats. Further, 20 genes (6 upregulated, 14 downregulated) were shared by both Tw and Tc groups. Thus, Celastrus treatment (Tc) significantly downregulated a large proportion of genes compared to controls (Tw). The DEG were mainly associated with the processes of immune response, cell proliferation and apoptosis, and cell signaling. These results provide novel insights into the mechanism of Celastrus anti-arthritic activity, and unravel potential therapeutic targets for arthritis. PMID:22697077

  18. Microarray evidence of glutaminyl cyclase gene expression in melanoma: implications for tumor antigen specific immunotherapy

    PubMed Central

    Gillis, John Stuart

    2006-01-01

    Background In recent years encouraging progress has been made in developing vaccine treatments for cancer, particularly with melanoma. However, the overall rate of clinically significant results has remained low. The present research used microarray datasets from previous investigations to examine gene expression patterns in cancer cell lines with the goal of better understanding the tumor microenvironment. Methods Principal Components Analyses with Promax rotational transformations were carried out with 90 cancer cell lines from 3 microarray datasets, which had been made available on the internet as supplementary information from prior publications. Results In each of the analyses a well defined melanoma component was identified that contained a gene coding for the enzyme, glutaminyl cyclase, which was as highly expressed as genes from a variety of well established biomarkers for melanoma, such as MAGE-3 and MART-1, which have frequently been used in clinical trials of melanoma vaccines. Conclusion Since glutaminyl cyclase converts glutamine and glutamic acid into a pyroglutamic form, it may interfere with the tumor destructive process of vaccines using peptides having glutamine or glutamic acid at their N-terminals. Finding ways of inhibiting the activity of glutaminyl cyclase in the tumor microenvironment may help to increase the effectiveness of some melanoma vaccines. PMID:16820060

  19. Release of soluble pilin antigen coupled with gene conversion in Neisseria gonorrhoeae.

    PubMed Central

    Haas, R; Schwarz, H; Meyer, T F

    1987-01-01

    Gene conversion appears to be the frequent mechanism in Neisseria gonorrhoeae that leads to an altered expression of pilin, the subunit component of the pili. In this process segments of variable sequence information, the minicassettes, are transferred from silent storage loci into an expression locus. As a putative consequence of the rearrangement in the pilE gene, gonococci can enter a different phase of pilin production. Although the removal of a 7-amino acid leader peptide results in the production of typical P+ pilin used to form pili, the loss of an additional 39 amino acids yields S-pilin, a soluble form of pilin that is efficiently secreted into the extracellular environment. Both pilin types can coexist in an apparently homogeneous culture. Ps cells usually are piliated, although less extensively with regard to the length and the number of the pili when compared with P+ cells. Ps cells form T3/T4-type colonies also typical of nonpiliated cells (P-). The observations further suggest that the classical nonsecretory P- phenotype is not generated as a rule by precise gene conversion but rather by genetic changes that cause the production of an over-length pilin (L-pilin). Images PMID:2892194

  20. Dual oncogenic and tumor suppressor roles of the promyelocytic leukemia gene in hepatocarcinogenesis associated with hepatitis B virus surface antigen.

    PubMed

    Chung, Yih-Lin; Wu, Mei-Ling

    2016-05-10

    Proteasome-mediated degradation of promyelocytic leukemia tumor suppressor (PML) is upregulated in many viral infections and cancers. We previously showed that PML knockdown promotes early-onset hepatocellular carcinoma (HCC) in hepatitis B virus surface antigen (HBsAg)-transgenic mice. Here we report the effects of PML restoration on late-onset HBsAg-induced HCC. We compared protein expression patterns, genetic mutations and the effects of pharmacologically targeting PML in wild-type, PML-/-, PML+/+HBsAgtg/o and PML-/-HBsAgtg/o mice. PML-/- mice exhibited somatic mutations in DNA repair genes and developed severe steatosis and proliferative disorders, but not HCC. PML-/-HBsAgtg/o mice exhibited early mutations in cancer driver genes and developed hyperplasia, fatty livers and indolent adipose-like HCC. In PML+/+HBsAg-transgenic mice, HBsAg expression declined over time, and HBsAg-associated PML suppression was concomitantly relieved. Nevertheless, these mice accumulated mutations in genes contributing to oxidative stress pathways and developed aggressive late-onset angiogenic trabecular HCC. PML inhibition using non-toxic doses of arsenic trioxide selectively killed long-term HBsAg-affected liver cells in PML+/+HBsAgtg/o mice with falling HBsAg and rising PML levels, but not normal liver cells or early-onset HCC cells in PML-/-HBsAgtg/0 mice. These findings suggest dual roles for PML as a tumor-suppressor lost in early-onset HBsAg-induced hepatocarcinogenesis and as an oncogenic promoter in late-onset HBsAg-related HCC progression. PMID:27058621

  1. Comparative antigen-induced gene expression profiles unveil novel aspects of susceptibility/resistance to adjuvant arthritis in rats.

    PubMed

    Yu, Hua; Lu, Changwan; Tan, Ming T; Moudgil, Kamal D

    2013-12-01

    Lewis (LEW) and Wistar Kyoto (WKY) rats of the same major histocompatibility complex (MHC) haplotype (RT.1(l)) display differential susceptibility to adjuvant-induced arthritis (AIA). LEW are susceptible while WKY are resistant to AIA. To gain insights into the mechanistic basis of these disparate outcomes, we compared the gene expression profiles of the draining lymph node cells (LNC) of these two rat strains early (day 7) following a potentially arthritogenic challenge. LNC were tested both ex vivo and after restimulation with the disease-related antigen, mycobacterial heat-shock protein 65. Biotin-labeled fragment cRNA was generated from RNA of LNC and then hybridized with an oligonucleotide-based DNA microarray chip. The differentially expressed genes (DEG) were compared by limiting the false discovery rate to <5% and fold change ≥2.0, and their association with quantitative trait loci (QTL) was analyzed. This analysis revealed overall a more active immune response in WKY than LEW rats. Important differences were observed in the association of DEG with QTL in LEW vs. WKY rats. Both the number of upregulated DEG associated with rat arthritis-QTL and their level of expression were relatively higher in LEW when compared to WKY rat; however, the number of downregulated DEG-associated with rat arthritis-QTL as well as AIA-QTL were found to be higher in WKY than in LEW rats. In conclusion, distinct gene expression profiles define arthritis-susceptible versus resistant phenotype of MHC-compatible inbred rats. These results would advance our understanding of the pathogenesis of autoimmune arthritis and might also offer potential novel targets for therapeutic purposes. PMID:23911410

  2. 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.

  3. Preferentially Expressed Antigen of Melanoma (PRAME) and Wilms’ Tumor 1 (WT 1) Genes Expression in Childhood Acute Lymphoblastic Leukemia, Prognostic Role and Correlation with Survival

    PubMed Central

    Khateeb, Engy El; Morgan, Dalia

    2014-01-01

    BACKGROUND: Acute lymphocytic leukemia (ALL) is the most common hematologic malignancy in children. In young children it is also largely curable, with more than 90% of afflicted children achieving long-term remission. PRAME (Preferentially expressed antigen of melanoma) gene belongs to Group 3 class I HLA-restricted widely expressed antigens in which genes encoding widely expressed tumor antigens have been detected in many normal tissues as well as in histologically different types of tumors with no preferential expression on a certain type of cancer. It has been found to be expressed in a variety of cancer cells as leukemia & lymphoma. PRAME monitoring can be useful for detection of minimal residual disease and subsequent relapses particularly those leukemias in which specific tumor markers are unavailable. Wilms’ tumor1 (WT1) gene was identified as a gene that plays an important role in normal kidney development and inactivation of its function was shown to result in the development of Wilms’ tumors in paediatric patients. Disruption of WT1 function has been implicated in the formation of many different tumor types. AIM: to study how PRAME & WT 1 genes expression patterns influence cancer susceptibility & prognosis. PATIENTS & METHODS: 50 patients with denovo childhood acute lymphoblastic leukemia, as well as 50 age and sex matched apparently healthy volunteers were genotyped for PRAME and WT1 genes expression by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: PRAME gene was expressed in 34 of the patients (68%) and WT1 gene was expressed in 26 of the patients (52%). Expression of both genes was significantly higher compared to controls (P < 0.0001). Analysis of relapse free survival among our patients revealed that patients expressing PRAME gene or WT1 gene had better relapse free survival (p value=0.02 and 0.01 respectively). Relapse free survival increased significantly among patients coexpressing PRAME and WT 1(p value =0

  4. Comparison of O-Antigen Gene Clusters of All O-Serogroups of Escherichia coli and Proposal for Adopting a New Nomenclature for O-Typing

    PubMed Central

    DebRoy, Chitrita; Fratamico, Pina M.; Yan, Xianghe; Baranzoni, GianMarco; Liu, Yanhong; Needleman, David S.; Tebbs, Robert; O'Connell, Catherine D.; Allred, Adam; Swimley, Michelle; Mwangi, Michael; Kapur, Vivek; Raygoza Garay, Juan A.; Roberts, Elisabeth L.; Katani, Robab

    2016-01-01

    Escherichia coli strains are classified based on O-antigens that are components of the lipopolysaccharide (LPS) in the cell envelope. O-antigens are important virulence factors, targets of both the innate and adaptive immune system, and play a role in host-pathogen interactions. Because they are highly immunogenic and display antigenic specificity unique for each strain, O-antigens are the biomarkers for designating O-types. Immunologically, 185 O-serogroups and 11 OX-groups exist for classification. Conventional serotyping for O-typing entails agglutination reactions between the O-antigen and antisera generated against each O-group. The procedure is labor intensive, not always accurate, and exhibits equivocal results. In this report, we present the sequences of 71 O-antigen gene clusters (O-AGC) and a comparison of all 196 O- and OX-groups. Many of the designated O-types, applied for classification over several decades, exhibited similar nucleotide sequences of the O-AGCs and cross-reacted serologically. Some O-AGCs carried insertion sequences and others had only a few nucleotide differences between them. Thus, based on these findings, it is proposed that several of the E. coli O-groups may be merged. Knowledge of the O-AGC sequences facilitates the development of molecular diagnostic platforms that are rapid, accurate, and reliable that can replace conventional serotyping. Additionally, with the scientific knowledge presented, new frontiers in the discovery of biomarkers, understanding the roles of O-antigens in the innate and adaptive immune system and pathogenesis, the development of glycoconjugate vaccines, and other investigations, can be explored. PMID:26824864

  5. Comparison of O-Antigen Gene Clusters of All O-Serogroups of Escherichia coli and Proposal for Adopting a New Nomenclature for O-Typing.

    PubMed

    DebRoy, Chitrita; Fratamico, Pina M; Yan, Xianghe; Baranzoni, GianMarco; Liu, Yanhong; Needleman, David S; Tebbs, Robert; O'Connell, Catherine D; Allred, Adam; Swimley, Michelle; Mwangi, Michael; Kapur, Vivek; Raygoza Garay, Juan A; Roberts, Elisabeth L; Katani, Robab

    2016-01-01

    Escherichia coli strains are classified based on O-antigens that are components of the lipopolysaccharide (LPS) in the cell envelope. O-antigens are important virulence factors, targets of both the innate and adaptive immune system, and play a role in host-pathogen interactions. Because they are highly immunogenic and display antigenic specificity unique for each strain, O-antigens are the biomarkers for designating O-types. Immunologically, 185 O-serogroups and 11 OX-groups exist for classification. Conventional serotyping for O-typing entails agglutination reactions between the O-antigen and antisera generated against each O-group. The procedure is labor intensive, not always accurate, and exhibits equivocal results. In this report, we present the sequences of 71 O-antigen gene clusters (O-AGC) and a comparison of all 196 O- and OX-groups. Many of the designated O-types, applied for classification over several decades, exhibited similar nucleotide sequences of the O-AGCs and cross-reacted serologically. Some O-AGCs carried insertion sequences and others had only a few nucleotide differences between them. Thus, based on these findings, it is proposed that several of the E. coli O-groups may be merged. Knowledge of the O-AGC sequences facilitates the development of molecular diagnostic platforms that are rapid, accurate, and reliable that can replace conventional serotyping. Additionally, with the scientific knowledge presented, new frontiers in the discovery of biomarkers, understanding the roles of O-antigens in the innate and adaptive immune system and pathogenesis, the development of glycoconjugate vaccines, and other investigations, can be explored. PMID:26824864

  6. Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy.

    PubMed

    Kusabuka, Hotaka; Fujiwara, Kento; Tokunaga, Yusuke; Hirobe, Sachiko; Nakagawa, Shinsaku; Okada, Naoki

    2016-04-22

    Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%. The low transduction efficiency causes poor precision in the functional analysis of CAR-T cells. We attempted to improve the Rv gene transduction protocol to more efficiently generate functional CAR-T cells by optimizing the period of pre-cultivation and antibody stimulation. In the improved protocol, gene transduction efficiency to murine T cells was more than 90%. In addition, almost all of the prepared murine T cells expressed CAR after puromycin selection. These CAR-T cells had antigen-specific cytotoxic activity and secreted multiple cytokines by antigen stimulation. We believe that our optimized gene transduction protocol for murine T cells contributes to the advancement of T cell biology and development of immunotherapy using genetically engineered T cells. PMID:26993168

  7. Whole blood transcriptional profiling reveals significant down-regulation of human leukocyte antigen class I and II genes in essential thrombocythemia, polycythemia vera and myelofibrosis.

    PubMed

    Skov, Vibe; Riley, Caroline Hasselbalch; Thomassen, Mads; Larsen, Thomas Stauffer; Jensen, Morten K; Bjerrum, Ole Weis; Kruse, Torben A; Hasselbalch, Hans Carl

    2013-10-01

    Gene expression profiling studies in the Philadelphia-negative chronic myeloproliferative neoplasms have revealed significant deregulation of several immune and inflammation genes that might be of importance for clonal evolution due to defective tumor immune surveillance. Other mechanisms might be down-regulation of major histocompatibility (MHC) class I and II genes, which are used by tumor cells to escape antitumor T-cell-mediated immune responses. We have performed whole blood transcriptional profiling of genes encoding human leukocyte antigen (HLA) class I and II molecules, β2-microglobulin and members of the antigen processing machinery of HLA class I molecules (LMP2, LMP7, TAP1, TAP2 and tapasin). The findings of significant down-regulation of several of these genes may possibly be of major importance for defective tumor immune surveillance. Since up-regulation of HLA genes is recorded during treatment with epigenome modulating agents (DNA-hypomethylators and DNA-hyperacetylators [histone deacetylase inhibitors]) and interferon-α2, our findings call for prospective transcriptional studies of HLA genes during treatment with these agents. PMID:23302045

  8. TLR21's agonists in combination with Aeromonas antigens synergistically up-regulate functional TLR21 and cytokine gene expression in yellowtail leucocytes.

    PubMed

    Reyes-Becerril, Martha; Ascencio-Valle, Felipe; Hirono, Ikuo; Kondo, Hidehiro; Jirapongpairoj, Walissara; Esteban, Maria Angeles; Alamillo, Erika; Angulo, Carlos

    2016-08-01

    The purpose of this study was to characterize the TLR21 gene from yellowtail (Seriola lalandi) and its functional activity using TLR agonist stimulation and Aeromonas antigens. The TLR21 nucleotide sequence from yellowtail was obtained using the whole-genome shotgun sequencing method and bioinformatics tools. Basal TLR21 gene expression was analyzed in several tissues. Subsequently, the gene expression of TLR21 and cytokines IL-1β and TNF-α was evaluated in TLR agonist (CpG-ODN2006, LPS, and Poly I:C) exposing head kidney leucocytes, which were then subjected to Aeromonas antigen stimulation. The yellowtail full-length cDNA sequence of SlTLR21 was 3615 bp (980 aa) showing a high degree of similarity with the counterparts of other fish species and sharing the common structural architecture of the TLR family, including LRR domains, one C-terminal LRR region, and a TIR domain. Gene expression studies revealed the constitutive expression of TLR21 mRNA in all the analyzed tissues; the highest levels were observed in spleen and head kidney where they play an important role in the fish immune system. Transcripts of TLR21 and the downstream IL-1β and TNF-α cytokine genes were most strongly up-regulated after exposure to the TLR agonists following Aeromonas antigen stimulation, suggesting they are involved in immune response. The results indicated that TLR agonists, in combination with Aeromonas antigens in head kidney leucocytes, synergistically enhance TLR21 and cytokines in yellowtail. PMID:26987525

  9. The Effect of the Nonionic Block Copolymer Pluronic P85 on Gene Expression in Mouse Muscle and Antigen Presenting Cells

    PubMed Central

    Gaymalov, Zagit Z.; Yang, Zhihui; Pisarev, Vladimir M.; Alakhov, Valery Yu.; Kabanov, Alexander V.

    2008-01-01

    DNA vaccines can be greatly improved by polymer agents that simultaneously increase transgene expression and activate immunity. We describe here Pluronic P85 (P85), a triblock copolymer of ethylene oxide (EO) and propylene oxide (PO) EO26-PO40-EO26,. Using a mouse model we demonstrate that co-administration of a bacterial plasmid DNA with P85 in a skeletal muscle greatly increases gene expression in the injection site and distant organs, especially the draining lymph nodes and spleen. The reporter expression colocalizes with the specific markers of myocytes and keratinocytes in the muscle, as well as dendritic cells (DC) and macrophages in the muscle, lymph nodes and spleen. Furthermore, DNA/P85 and P85 alone increase the systemic expansion of CD11c+ (DC), and local expansion of CD11c+, CD14+ (macrophages) and CD49b+ (natural killer) cell populations. DNA/P85 (but not P85) also increases maturation of local DC (CD11c+CD86+, CD11c+CD80+, and CD11c+CD40+). We suggest that DNA/P85 promotes the activation and recruitment of the antigen-presenting cells, which further incorporate, express and carry the transgene to the immune system organs. PMID:19064283

  10. Novel Mutants Define Genes Required for the Expression of Human Histocompatibility Leukocyte Antigen DM: Evidence for Loci on Human Chromosome 6p

    PubMed Central

    Fling, Steven P.; Rak, Jennifer; Muczynski, Kimberly A.; Arp, Benjamin; Pious, Donald

    1997-01-01

    We and others have shown that the products of the HLA-DM locus are required for the intracellular assembly of major histocompatibility complex class II molecules with cognate peptides for antigen presentation. HLA-DM heterodimers mediate the dissociation of invariant chain (Ii)-derived class II–associated Ii peptides (CLIP) from class II molecules and facilitate the loading of class II molecules with antigenic peptides. Here we describe novel APC mutants with defects in the formation of class II–peptide complexes. These mutants express class II molecules which are conformationally altered, and an aberrantly high percentage of these class II molecules are associated with Ii-derived CLIP. This phenotype resembles that of DM null mutants. However, we show that the defects in two of these new mutants do not map to the DM locus. Nevertheless, our evidence suggests that the antigen processing defective phenotype in these mutants results from deficient DM expression. These mutants thus appear to define genes in which mutations have differential effects on the expression of conventional class II molecules and DM molecules. Our data are most consistent with these factors mapping to human chromosome 6p. Previous data have suggested that the expression of DM and class II genes are coordinately regulated. The results reported here suggest that DM and class II can also be differentially regulated, and that this differential regulation has significant effects on class II–restricted antigen processing. PMID:9348304

  11. Sequence Variation Analysis of Epstein-Barr Virus Nuclear Antigen 1 Gene in the Virus Associated Lymphomas of Northern China

    PubMed Central

    Sun, Lingling; Zhao, Zhenzhen; Liu, Song; Liu, Xia; Sun, Zhifu; Luo, Bing

    2015-01-01

    Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is the only viral protein expressed in all EBV-positive tumors as it is essential for the maintenance, replication and transcription of the virus genome. According to the polymorphism of residue 487 in EBNA1 gene, EBV isolates can be classified into five subtypes: P-ala, P-thr, V-val, V-leu and V-pro. Whether these EBNA1 subtypes contribute to different tissue tropism of EBV and are consequently associated with certain malignancies remain to be determined. To elucidate the relationship, one hundred and ten EBV-positive lymphoma tissues of different types from Northern China, a non-NPC endemic area, were tested for the five subtypes by nested-PCR and DNA sequencing. In addition, EBV type 1 and type 2 classification was typed by using standard PCR assays across type-specific regions of the EBNA3C genes. Four EBNA1 subtypes were identified: V-val (68.2%, 75/110), P-thrV (15.5%, 17/110), V-leuV (3.6%, 4/110) and P-ala (10.9%, 12/110). The distribution of the EBNA1 subtypes in the four lymphoma groups was not significantly different (p = 0.075), neither was that of the EBV type 1/type 2 (p = 0.089). Compared with the previous data of gastric carcinoma (GC), nasopharyngeal carcinoma (NPC) and throat washing (TW) from healthy donors, the distribution of EBNA1 subtypes in lymphoma differed significantly (p = 0.016), with a little higher frequency of P-ala subtype. The EBV type distribution between lymphoma and the other three groups was significantly different (p = 0.000, p = 0.000, p = 0.001, respectively). The proportion of type 1 and type 2 mixed infections was higher in lymphoma than that in GC, NPC and TW. In lymphomas, the distribution of EBNA1 subtypes in the three EBV types was not significantly different (p = 0.546). These data suggested that the variation patterns of EBNA1 gene may be geographic-associated rather than tumor-specific and the role of EBNA1 gene variations in tumorigenesis needs more extensive and

  12. Genetic detection of Babesia bigemina from Mongolian cattle using apical membrane antigen-1 gene-based PCR assay.

    PubMed

    Sivakumar, Thillaiampalam; Altangerel, Khukhuu; Battsetseg, Badgar; Battur, Banzragch; Aboulaila, Mahmoud; Munkhjargal, Tserendorj; Yoshinari, Takeshi; Yokoyama, Naoaki; Igarashi, Ikuo

    2012-06-01

    We developed a new nested PCR (nPCR) assay based on the Babesia bigemina apical membrane antigen-1 (AMA-1) gene sequence for parasite-specific detection. The primers were designed to amplify 738-bp and 211-bp fragments of the AMA-1 gene by primary and nested PCRs, respectively. The assay was proven to be specific for the B. bigemina, whereas the previously established SpeI-AvaI nPCR assay amplified not only the target fragment of B. bigemina but also a homologous one from Babesia ovata. The AMA-1 nPCR assay was also evaluated using field DNA samples extracted from 266 bovine blood samples collected from Mongolia in 2010. In a comparative evaluation, 90 (33.8%) and 25 (9.4%) of the blood samples showed positive reactions for B. bigemina by the SpeI-AvaI nPCR and AMA-1 nPCR assays, respectively. The sequencing analysis of the nPCR products confirmed that the AMA-1 nPCR method had specifically detected the target B. bigemina DNA. However, 4 different kinds of sequences were determined among the SpeI-AvaI nPCR amplicons. Two of them were derived from B. bigemina and B. ovata, while the origins of the others were unknown. In the current study, the presence of B. bigemina was clearly demonstrated among Mongolian cattle populations by the current nPCR assay for the first time. Furthermore, our findings also indicate that the AMA-1 nPCR assay may be a useful diagnostic tool for the specific detection of B. bigemina. PMID:22284301

  13. Identification and Validation of HCC-specific Gene Transcriptional Signature for Tumor Antigen Discovery

    PubMed Central

    Petrizzo, Annacarmen; Caruso, Francesca Pia; Tagliamonte, Maria; Tornesello, Maria Lina; Ceccarelli, Michele; Costa, Valerio; Aprile, Marianna; Esposito, Roberta; Ciliberto, Gennaro; Buonaguro, Franco M.; Buonaguro, Luigi

    2016-01-01

    A novel two-step bioinformatics strategy was applied for identification of signatures with therapeutic implications in hepatitis-associated HCC. Transcriptional profiles from HBV- and HCV-associated HCC samples were compared with non-tumor liver controls. Resulting HCC modulated genes were subsequently compared with different non-tumor tissue samples. Two related signatures were identified, namely “HCC-associated” and “HCC-specific”. Expression data were validated by RNA-Seq analysis carried out on unrelated HCC samples and protein expression was confirmed according to The Human Protein Atlas" (http://proteinatlas.org/), a public repository of immunohistochemistry data. Among all, aldo-keto reductase family 1 member B10, and IGF2 mRNA-binding protein 3 were found strictly HCC-specific with no expression in 18/20 normal tissues. Target peptides for vaccine design were predicted for both proteins associated with the most prevalent HLA-class I and II alleles. The described novel strategy showed to be feasible for identification of HCC-specific proteins as highly potential target for HCC immunotherapy. PMID:27387388

  14. 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...

  15. 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

  16. Cloning and Expression of Major Surface Antigen 1 Gene of Toxoplasma gondii RH Strain Using the Expression Vector pVAX1 in Chinese Hamster Ovary Cells

    PubMed Central

    Abdizadeh, Rahman; Maraghi, Sharif; Ghadiri, Ata A.; Tavalla, Mehdi; Shojaee, Saeedeh

    2015-01-01

    Background: Toxoplasmosis is an opportunistic protozoan infection with a high prevalence in a broad range of hosts infecting up to one-third of the world human population. Toxoplasmosis leads to serious medical problems in immunocompromised individuals and fetuses and also induces abortion and mortality in domestic animals. Therefore, there is a huge demand for the development of an effective vaccine. Surface Antigen 1 (SAG1) is one of the important immunodominant surface antigens of Toxoplasma gondii, which interacts with host cells and primarily involved in adhesion, invasion and stimulation of host immune response. Surface antigen 1 is considered as the leading candidate for development of an effective vaccine against toxoplasmosis. Objectives: The purpose of this study was to clone the major surface antigen1 gene (SAG1) from the genotype 1 of T. gondii, RH strain into the eukaryotic expression vector pVAX1 in order to use for a DNA vaccine. Materials and Methods: Genomic DNA was extracted from tachyzoite of the parasite using the QIAamp DNA mini kit. After designing the specific primers, SAG1 gene was amplified by Polymerase Chain Reaction (PCR). The purified PCR products were then cloned into a pPrime plasmid vector. The aforementioned product was subcloned into the pVAX1 eukaryotic expression vector. The recombinant pVAX1-SAG1 was then transfected into Chinese Hamster Ovary (CHO) cells and expression of SAG1 antigen was evaluated using Reverse Transcriptase Polymerase Chain Reaction (RT-PCR), Immunofluorescence Assay (IFA) and Western Blotting (WB). Results: The cloning and subcloning products (pPrime-SAG1 and pVAX1-SAG1 plasmid vectors) of SAG1 gene were verified and confirmed by enzyme digestion and sequencing. A 30 kDa recombinant protein was expressed in CHO cells as shown by IFA and WB methods. Conclusions: The pVAX1 expression vector and CHO cells are a suitable system for high-level recombinant protein production for SAG1 gene from T. gondii parasites

  17. Use of human antigen presenting cell gene array profiling to examine the effect of human T-cell leukemia virus type 1 Tax on primary human dendritic cells.

    PubMed

    Ahuja, Jaya; Kampani, Karan; Datta, Suman; Wigdahl, Brian; Flaig, Katherine E; Jain, Pooja

    2006-02-01

    Human T-cell leukemia virus type 1 (HTLV-1) is etiologically linked to adult T-cell leukemia and a progressive demyelinating disorder termed HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). One of the most striking features of the immune response in HAM/TSP centers on the expansion of HTLV-1-specific CD8(+) cytotoxic T lymphocyte (CTL) compartment in the peripheral blood and cerebrospinal fluid. More than 90% of the HTLV-1-specific CTLs are directed against the viral Tax (11-19) peptide implying that Tax is available for immune recognition by antigen presenting cells, such as dendritic cells (DCs). DCs obtained from HAM/TSP patients have been shown to be infected with HTLV-1 and exhibit rapid maturation. Therefore, we hypothesized that presentation of Tax peptides by activated DCs to naIve CD8(+) T cells may play an important role in the induction of a Tax-specific CTL response and neurologic dysfunction. In this study, a pathway-specific antigen presenting cell gene array was used to study transcriptional changes induced by exposure of monocyte-derived DCs to extracellular HTLV-1 Tax protein. Approximately 100 genes were differentially expressed including genes encoding toll-like receptors, cell surface receptors, proteins involved in antigen uptake and presentation and adhesion molecules. The differential regulation of chemokines and cytokines characteristic of functional DC activation was also observed by the gene array analyses. Furthermore, the expression pattern of signal transduction genes was also significantly altered. These results have suggested that Tax-mediated DC gene regulation might play a critical role in cellular activation and the mechanisms resulting in HTLV-1-induced disease. PMID:16595374

  18. Expression of the CMRF-35 antigen, a new member of the immunoglobulin gene superfamily, is differentially regulated on leucocytes.

    PubMed Central

    Daish, A; Starling, G C; McKenzie, J L; Nimmo, J C; Jackson, D G; Hart, D N

    1993-01-01

    A new monoclonal antibody, CMRF-35, has been generated that recognized a 224 amino acid cell surface protein which is a novel member of the immunoglobulin gene superfamily. The antibody, raised against large granular lymphocytes (LGL), stains LGL, monocytes, macrophages and granulocytes but not platelets or erythrocytes. In addition, a subset of peripheral blood T lymphocytes (26.6 +/- 13.4% CD5+ cells) and B lymphocytes (13.7 +/- 6.8% CD20+ cells) stained with CMRF-35 but tonsil T and B cells were essentially negative. Expression of the CMRF-35 antigen (Ag) on different leucocyte populations was markedly influenced by stimulation of the cells with mitogens and cytokines. Activation of peripheral blood T cells with phytohaemagglutinin (PHA), or phorbol myristate acetate (PMA) and calcium ionophore (CaI) led to a decrease in the proportion of CMRF-35+ T lymphocytes. In contrast, PHA activation of tonsil T lymphocytes resulted in an increase in CMRF-35 Ag expression (47.1 +/- 1.5% CD5 cells at 6 days). An increase in CMRF-35 Ag was also seen on phorbol ester and CaI-activated tonsil B cells. No change in CMRF-35 expression on natural killer (NK) cells occurred following activation with interleukin-2 (IL-2) but the CMRF-35 Ag was down-regulated following Fc receptor stimulation. A moderate increase in CMRF-35 expression occurred during monocyte-macrophage differentiation and the expression of the Ag on monocytes was differentially regulated by interferon-gamma (IFN-gamma). This regulation of the CMRF-35 Ag on the leucocyte surface suggests that the molecule has an important function common to diverse leucocyte types. PMID:8509141

  19. 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

  20. Simian virus 40 T antigen can transcriptionally activate and mediate viral DNA replication in cells which lack the retinoblastoma susceptibility gene product.

    PubMed Central

    Trifillis, P; Picardi, J; Alwine, J C

    1990-01-01

    Simian virus 40 T antigen is a multifunctional protein which has recently been shown to form a complex with the retinoblastoma susceptibility gene product (Rb protein) (J.A. DeCaprio, J.W. Ludlow, J. Figge, J.-Y. Shaw, C.-M. Huang, W.-H. Lee, E. Marsilio, E. Paucha, and D.M. Livingston, Cell 54:275-283, 1988; P. Whyte, K.J. Buchkovich, J.M. Horowitz, S.H. Friend, M. Raybuck, R.A. Weinberg, and E. Harlow, Nature (London) 334:124-129, 1988). This interaction may facilitate some of the functions of T antigen. The ability of simian virus 40 T antigen to mediate transcriptional activation and viral DNA replication was tested in human osteosarcoma cell lines U-2OS and Saos-2, which are Rb positive and Rb negative, respectively. Both functions of T antigen were efficient in both cell lines. Hence, these functions can occur in the absence of Rb protein. Images PMID:2154611

  1. Association of human leukocyte antigen DP/DQ gene polymorphisms with chronic hepatitis B in Chinese Han and Uygur populations.

    PubMed

    Xiang, Xin; Guo, Yuxuan; Yang, Li; Ge, Qinghui; Mijit, Sadatgul; Xu, Feili

    2016-09-01

    Several genome-wide association studies (GWAS) have shown that human leukocyte antigen (HLA) DP/DQ gene polymorphisms are associated with susceptibility to chronic hepatitis B virus (HBV) infection. We clarified the roles of the HLA-DP/DQ gene in HBV infection in different nationalities. Three single nucleotide polymorphisms (SNPs) in HLA-DP (rs9277471, rs9277535 and rs9277542) and the SNP rs9272346 in HLA-DQ were studied. In total, 779 patients were recruited to this study, including 400 Chinese Han and 399 Uygurs. The rs9277535 variant genotypes were directly associated with HBV persistence compared to healthy controls in an additive model of the Chinese Han population (odds ratio [OR]=1.88, 95% confidence interval [CI]=1.03-3.41, P=0.040), and in a recessive model of the Chinese female population (OR=2.02, 95% CI=1.26-3.24, P=0.003). In addition, rs9277471 and rs9277542 variant genotypes significantly decreased the risk of HBV infection compared to healthy controls in an additive model of the Chinese Han population (OR=0.53, 95% CI=0.29-0.98, P=0.042; OR=0.53, 95% CI=0.29-0.97, P=0.039) and in a dominant model of the Chinese female population (OR=0.50, 95% CI=0.31-0.80, P=0.004; OR=0.49, 95% CI=0.31-0.79, P=0.003). The GG genotype of rs9277346 was associated with HBV infection in the Chinese Han population (additive model: OR=0.38, 95%CI=017-0.82, P=0.014; recessive model: OR=0.41, 95% CI=0.19-0.86, P=0.019) and in males (additive model: OR=0.31, 95% CI=0.14-0.65, P=0.002; dominant model: OR=0.65, 95% CI=0.43-0.97, P=0.034; recessive model: OR=0.36, 95% CI=0.18-0.73, P=0.005). In addition, allele G of rs9277346 was marginally related to a reduction in risk for HBV infection in the Uygur population. Our study suggests that HLA-DP/DQ polymorphisms can affect susceptibility and resistance to HBV infection in Chinese populations, and are possibly linked to race and sex. PMID:27291710

  2. Inhibition of the HCV core protein on the immune response to HBV surface antigen and on HBV gene expression and replication in vivo.

    PubMed

    Zhu, Wenbo; Wu, Chunchen; Deng, Wanyu; Pei, Rongjun; Wang, Yun; Cao, Liang; Qin, Bo; Lu, Mengji; Chen, Xinwen

    2012-01-01

    The hepatitis C virus (HCV) core protein is a multifunctional protein that can interfere with the induction of an immune response. It has been reported that the HCV core protein inhibits HBV replication in vitro. In this study, we test the effect of the HCV core gene on the priming of the immune response to hepatitis B surface antigen (HBsAg) and on the replication of HBV in vivo. Our results showed that the full-length HCV core gene inhibits the induction of an immune response to the heterogeneous antigen, HBsAg, at the site of inoculation when HCV core (pC191) and HBsAg (pHBsAg) expression plasmids are co-administered as DNA vaccines into BALB/c mice. The observed interference effect of the HCV core occurs in the priming stage and is limited to the DNA form of the HBsAg antigen, but not to the protein form. The HCV core reduces the protective effect of the HBsAg when the HBsAg and the HCV core are co-administered as vaccines in an HBV hydrodynamic mouse model because the HCV core induces immune tolerance to the heterogeneous HBsAg DNA antigen. These results suggest that HCV core may play an important role in viral persistence by the attenuation of host immune responses to different antigens. We further tested whether the HCV core interfered with the priming of the immune response in hepatocytes via the hydrodynamic co-injection of an HBV replication-competent plasmid and an HCV core plasmid. The HCV core inhibited HBV replication and antigen expression in both BALB/c (H-2d) and C57BL/6 (H-2b) mice, the mouse models of acute and chronic hepatitis B virus infections. Thus, the HCV core inhibits the induction of a specific immune response to an HBsAg DNA vaccine. However, HCV C also interferes with HBV gene expression and replication in vivo, as observed in patients with coinfection. PMID:23024803

  3. The Yersinia pestis V antigen is a regulatory protein necessary for Ca2(+)-dependent growth and maximal expression of low-Ca2+ response virulence genes.

    PubMed Central

    Price, S B; Cowan, C; Perry, R D; Straley, S C

    1991-01-01

    The low-Ca2+ response is a multicomponent virulence regulon of the human-pathogenic yersiniae in which 12 known virulence genes are coordinately regulated in response to environmental cues of temperature, Ca2+, and nucleotides such as ATP. Yersinial growth also is regulated, with full growth yield being permitted at 37 degrees C only if Ca2+ or a nucleotide is present. In this study, we constructed and characterized a mutant Yersinia pestis specifically defective in the gene encoding the V antigen, one of the virulence genes of the low-Ca2+ response. An in-frame internal deletion-insertion mutation was made by removing bases 51 through 645 of lcrV and inserting 61 new bases. The altered lcrV was introduced into the low-Ca2+ response plasmid in Y. pestis by allelic exchange, and the resulting mutant was characterized for its two-dimensional protein profiles, growth, expression of an operon fusion to another low-Ca2+ response virulence operon, and virulence in mice. The mutant had lost its Ca2+ and nucleotide requirement for growth, showed diminished expression of Ca2(+)-and nucleotide-regulated virulence genes, and was avirulent in mice. The mutation could be complemented with respect to the growth property by supplying native V antigen operon sequences in trans in high copy number (on pBR322). Partial complementation of the growth defect and almost complete complementation of the virulence defect were seen with a lower-copy-number complementing replicon (a pACYC184 derivative). The data are consistent with the interpretation that V antigen is bifunctional, with a role in regulating growth and expression of low-Ca2+ response virulence genes in addition to its putative role as a secreted virulence protein. Images PMID:1901573

  4. Antigens and cytokine genes in antitumor vaccines: the importance of the temporal delivery sequence in antitumor signals.

    PubMed

    Herrero, María José; Botella, Rafael; Dasí, Francisco; Algás, Rosa; Sánchez, María; Aliño, Salvador F

    2006-12-01

    Studies against cancer, including clinical trials, have shown that a correct activation of the immune system can lead to tumor rejection whereas incorrect signaling results in no positive effects or even anergy. We have worked assuming that two signals, GM-CSF (granulocyte and macrophage colony-stimulating factor) and tumor antigens are necessary to mediate an antitumor effective response. To study which is the ideal temporal sequence for their administration, we have used a murine model of antimelanoma vaccine employing whole B16 tumor cells or their membrane protein antigens (TMPs) in combination with gm-csf transfer before or after the antigen delivery. Our results show that: (i) When gm-csf tisular transfection is performed before TMP delivery, a tumor growth inhibition is observed, but with a limit effect when administering high antigen doses; in contrast, when signals are inverted, the limited effect is lost and greater antitumor efficacy is obtained. (ii) A similar behavior, but with stronger positive results, is observed employing gm-csf transfection and whole tumor cells as antigens. While negative results are obtained with gm-csf before cells, the best results (total survival of treated mice) are obtained when GM-CSF is administered in transfected cells. We conclude that optimal antitumoral response can be obtained when the antigen signal is given before (or simultaneous with) GM-CSF production, while the inversion of the signals could result in the undesired inhibition or anergy of the immune response. PMID:17341632

  5. 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

  6. Human Leukocyte Antigen (HLA) A*1101-restricted Epstein-Barr Virus-specific T-cell Receptor Gene Transfer to Target Nasopharyngeal Carcinoma

    PubMed Central

    Zheng, Yong; Parsonage, Greg; Zhuang, Xiaodong; Machado, Lee R; James, Christine H.; Salman, Asmaa; Searle, Peter F.; Hui, Edwin P.; Chan, Anthony T.C.; Lee, Steven P.

    2015-01-01

    Infusing virus-specific T cells is effective treatment for rare Epstein-Barr virus (EBV)-associated post-transplant lymphomas and more limited success has been reported using this approach to treat a far more common EBV-associated malignancy, nasopharyngeal carcinoma (NPC). However, current approaches using EBV-transformed lymphoblastoid cell lines to reactivate EBV-specific T cells for infusion take 2 to 3 months of in vitro culture and favour outgrowth of T cells targeting viral antigens expressed within EBV+ lymphomas but not in NPC. Here we explore T-cell receptor (TCR) gene transfer to rapidly and reliably generate T cells specific for the NPC-associated viral protein LMP2. We cloned a HLA A*1101-restricted TCR, which would be widely applicable since 40% of NPC patients carry this HLA allele. Studying both the wild-type and modified forms we have optimised expression of the TCR and demonstrated high avidity antigen-specific function (proliferation, cytotoxicity, cytokine release) in both CD8+ and CD4+ T cells. The engineered T cells also inhibited LMP2+ epithelial tumour growth in a mouse model. Furthermore, transduced T cells from patients with advanced NPC lysed LMP2-expressing NPC cell lines. Using this approach, within a few days large numbers of high avidity LMP2-specific T cells can be generated reliably to treat NPC, thus providing an ideal clinical setting to test TCR gene transfer without the risk of autoimmunity through targeting self-antigens. PMID:25711537

  7. The pregnancy-specific glycoprotein (PSG) gene cluster on human chromosome 19: Fine structure of the 11 PSG genes and identification of 6 new genes forming a third subgroup within the carcinoembryonic antigen (CEA) family

    SciTech Connect

    Teglund, S.; Fraengsmyr, L.; Hammarstroem, S.

    1994-10-01

    The human pregnancy-specific glycoprotein (PSG) genes belong to the carcinoembryonic antigen (CEA) family, which in turn is a member of the immunoglobulin superfamily. We have analyzed a 700-kb cosmid contig spanning the PSG region on chromosome 19q13.2. The region contains 11 closely related PSG genes organized in tandem with a highly conserved structure and organization. Seven novel genes (CGM12 to CGM18) were found in the PSG region. CGM12 belongs to the CEA subgroup and appears to be a pseudogene. CGM13 to CGM18 forms a third new subgroup within the CEA gene family. The members of this new subgroup show 94-99% identity to each other but only 70-80% to other members of either the CEA or the PSG subgroups. They are composed of exons encoding two IgC-like domains and short hydrophilic carboxyl terminals similar to those of the PSGs. Unlike any of the known CEA family genes, however, they seem to lack the exon for an IgV-like N-terminal domain. 54 refs., 6 figs., 4 tabs.

  8. Gene silencing of the tick protective antigens, Bm86, Bm91 and subolesin, in the one-host tick Boophilus microplus by RNA interference.

    PubMed

    Nijhof, Ard M; Taoufik, Amar; de la Fuente, José; Kocan, Katherine M; de Vries, Erik; Jongejan, Frans

    2007-05-01

    The use of RNA interference (RNAi) to assess gene function has been demonstrated in several three-host tick species but adaptation of RNAi to the one-host tick, Boophilus microplus, has not been reported. We evaluated the application of RNAi in B. microplus and the effect of gene silencing on three tick-protective antigens: Bm86, Bm91 and subolesin. Gene-specific double-stranded (dsRNA) was injected into two tick stages, freshly molted unfed and engorged females, and specific gene silencing was confirmed by real time PCR. Gene silencing occurred in injected unfed females after they were allowed to feed. Injection of dsRNA into engorged females caused gene silencing in the subsequently oviposited eggs and larvae that hatched from these eggs, but not in adults that developed from these larvae. dsRNA injected into engorged females could be detected by quantitative real-time RT-PCR in eggs 14 days from the beginning of oviposition, demonstrating that unprocessed dsRNA was incorporated in the eggs. Eggs produced by engorged females injected with subolesin dsRNA were abnormal, suggesting that subolesin may play a role in embryonic development. The injection of dsRNA into engorged females to obtain gene-specific silencing in eggs and larvae is a novel method which can be used to study gene function in tick embryogenesis. PMID:17196597

  9. Hepatitis B Surface Antigen S Gene is an Effective Carrier Molecule for Developing GnRH DNA Immunocastration Vaccine in Mice.

    PubMed

    Han, Y G; Ye, W J; Liu, G Q; Jiang, X P; Ijaz, N; Zhao, J Y; Tesema, B

    2016-06-01

    Relatively molecular mass of GnRH antigens is small and hence needs to couple to a large carrier molecule to enhance its immunogenicity. This study investigated whether hepatitis B surface antigen S (HBsAg-S) gene can be used as an effective carrier molecule for developing GnRH DNA immunocastration vaccine. Two copies of human GnRH gene were fused with HBsAg-S gene for constructing a recombinant plasmid pVAX-HBsAg-S-2GnRH that coded for 27 kDa target fusion protein. Ten male mice were divided into two equal groups, treatment and control. The vaccine (50 μg/mice) prepared in saline solution was injected into male mice at weeks 0, 1, 2, 4 and 7 of the experiment. Vaccine's efficacy was evaluated in terms of GnRH-specific IgG antibody response, plasma testosterone levels, testicular weight and extent of the testicular tissue damage. The specific anti-GnRH antibody titre in vaccinated animals was significantly higher than in controls in only 4th week of immunization (p < 0.05). In addition, vaccinated animals showed lower testicular weight than those of the controls (p < 0.05). Spermatogenesis in seminiferous tubules in vaccinated animals was suppressed. In conclusion, in this study, the engineered plasmid to be used as a GnRH DNA vaccine induced antibody response and suppressed spermatogenesis in mice. This suggests that HBsAg-S gene can be an effective carrier molecule for developing GnRH DNA immunocastration vaccine when relatively molecular mass of the aimed antigens is small. PMID:27157596

  10. Autoimmune type 1 diabetes genetic susceptibility encoded by human leukocyte antigen DRB1 and DQB1 genes in Tunisia.

    PubMed

    Stayoussef, Mouna; Benmansour, Jihen; Al-Irhayim, Abdul-Qader; Said, Hichem B; Rayana, Chiheb B; Mahjoub, Touhami; Almawi, Wassim Y

    2009-08-01

    Human leukocyte antigen (HLA) class II genes contribute to the genetic susceptibility to type 1 diabetes (T1D), and susceptible alleles and haplotypes were implicated in the pathogenesis of T1D. This study investigated the heterogeneity in HLA class II haplotype distribution among Tunisian patients with T1D. This was a retrospective case control study done in Monastir in central Tunisia. The subjects comprised 88 T1D patients and 112 healthy controls. HLA-DRB1 and -DQB1 genotyping was done by PCR-sequence-specific priming. Significant DRB1 and DQB1 allelic differences were seen between T1D patients and controls; these differences comprised DRB1*030101 and DQB1*0302, which were higher in T1D patients than in control subjects, and DRB1*070101, DRB1*110101, DQB1*030101, and DQB1*060101, which were lower in T1D patients than in control subjects. In addition, the frequencies of DRB1*030101-DQB1*0201 and DRB1*040101-DQB1*0302 were higher in T1D patients than in control subjects, and the frequencies of DRB1*070101-DQB1*0201 and DRB1*110101-DQB1*030101 haplotypes were lower in T1D patients than in control subjects. Multiple logistic regression analysis revealed the positive association of DRB1*030101-DQB1*0201 and DRB1*040101-DQB1*0302 and the negative association of only DRB1*070101-DQB1*0201 haplotypes with T1D. Furthermore, a significantly increased prevalence of DRB1*030101-DQB1*0201 homozygotes was seen for T1D subjects than for control subjects. Our results confirm the association of specific HLA-DR and -DQ alleles and haplotypes with T1D in Tunisians. The identification of similar and unique haplotypes in Tunisians compared to other Caucasians highlights the need for evaluating the contribution of HLA class II to the genetic susceptibility to T1D with regard to haplotype usage and also to ethnic origin and racial background. PMID:19553558

  11. Autoimmune Type 1 Diabetes Genetic Susceptibility Encoded by Human Leukocyte Antigen DRB1 and DQB1 Genes in Tunisia▿

    PubMed Central

    Stayoussef, Mouna; Benmansour, Jihen; Al-Irhayim, Abdul-Qader; Said, Hichem B.; Rayana, Chiheb B.; Mahjoub, Touhami; Almawi, Wassim Y.

    2009-01-01

    Human leukocyte antigen (HLA) class II genes contribute to the genetic susceptibility to type 1 diabetes (T1D), and susceptible alleles and haplotypes were implicated in the pathogenesis of T1D. This study investigated the heterogeneity in HLA class II haplotype distribution among Tunisian patients with T1D. This was a retrospective case control study done in Monastir in central Tunisia. The subjects comprised 88 T1D patients and 112 healthy controls. HLA-DRB1 and -DQB1 genotyping was done by PCR-sequence-specific priming. Significant DRB1 and DQB1 allelic differences were seen between T1D patients and controls; these differences comprised DRB1*030101 and DQB1*0302, which were higher in T1D patients than in control subjects, and DRB1*070101, DRB1*110101, DQB1*030101, and DQB1*060101, which were lower in T1D patients than in control subjects. In addition, the frequencies of DRB1*030101-DQB1*0201 and DRB1*040101-DQB1*0302 were higher in T1D patients than in control subjects, and the frequencies of DRB1*070101-DQB1*0201 and DRB1*110101-DQB1*030101 haplotypes were lower in T1D patients than in control subjects. Multiple logistic regression analysis revealed the positive association of DRB1*030101-DQB1*0201 and DRB1*040101-DQB1*0302 and the negative association of only DRB1*070101-DQB1*0201 haplotypes with T1D. Furthermore, a significantly increased prevalence of DRB1*030101-DQB1*0201 homozygotes was seen for T1D subjects than for control subjects. Our results confirm the association of specific HLA-DR and -DQ alleles and haplotypes with T1D in Tunisians. The identification of similar and unique haplotypes in Tunisians compared to other Caucasians highlights the need for evaluating the contribution of HLA class II to the genetic susceptibility to T1D with regard to haplotype usage and also to ethnic origin and racial background. PMID:19553558

  12. Cloning of the complete gene for carcinoembryonic antigen: analysis of its promoter indicates a region conveying cell type-specific expression.

    PubMed Central

    Schrewe, H; Thompson, J; Bona, M; Hefta, L J; Maruya, A; Hassauer, M; Shively, J E; von Kleist, S; Zimmermann, W

    1990-01-01

    Carcinoembryonic antigen (CEA) is a widely used tumor marker, especially in the surveillance of colonic cancer patients. Although CEA is also present in some normal tissues, it is apparently expressed at higher levels in tumorous tissues than in corresponding normal tissues. As a first step toward analyzing the regulation of expression of CEA at the transcriptional level, we have isolated and characterized a cosmid clone (cosCEA1), which contains the entire coding region of the CEA gene. A close correlation exists between the exon and deduced immunoglobulin-like domain borders. We have determined a cluster of transcriptional starts for CEA and the closely related nonspecific cross-reacting antigen (NCA) gene and have sequenced their putative promoters. Regions of sequence homology are found as far as approximately 500 nucleotides upstream from the translational starts of these genes, but farther upstream they diverge completely. In both cases we were unable to find classic TATA or CAAT boxes at their expected positions. To characterize the CEA and NCA promoters, we carried out transient transfection assays with promoter-indicator gene constructs in the CEA-producing adenocarcinoma cell line SW403, as well as in nonproducing HeLa cells. A CEA gene promoter construct, containing approximately 400 nucleotides upstream from the translational start, showed nine times higher activity in the SW403 than in the HeLa cell line. This indicates that cis-acting sequences which convey cell type-specific expression of the CEA gene are contained within this region. Images PMID:2342461

  13. Immune Responses Induced by Gene Gun or Intramuscular Injection of DNA Vaccines That Express Immunogenic Regions of the Serine Repeat Antigen from Plasmodium falciparum

    PubMed Central

    Belperron, Alexia A.; Feltquate, David; Fox, Barbara A.; Horii, Toshihiro; Bzik, David J.

    1999-01-01

    The liver- and blood-stage-expressed serine repeat antigen (SERA) of Plasmodium falciparum is a candidate protein for a human malaria vaccine. We compared the immune responses induced in mice immunized with SERA-expressing plasmid DNA vaccines delivered by intramuscular (i.m.) injection or delivered intradermally by Gene Gun immunization. Mice were immunized with a pcdna3 plasmid encoding the entire 47-kDa domain of SERA (amino acids 17 to 382) or the N-terminal domain (amino acids 17 to 110) of SERA. Minimal antibody responses were detected following DNA vaccination with the N-terminal domain of SERA, suggesting that the N-terminal domain alone is not highly immunogenic by this route of vaccine delivery. Immunization of mice by Gene Gun delivery of the 47-kDa domain of SERA elicited a significantly higher serum antibody titer to the antigen than immunization of mice by i.m. injection with the same plasmid did. The predominant isotype subclass of the antibodies elicited to the SERA protein following i.m. and Gene Gun immunizations with SERA plasmid DNA was immunoglobulin G1. Coimmunization of mice with SERA plasmid DNA and a plasmid expressing the hepatitis B surface antigen (pCMV-s) by the i.m. route resulted in higher anti-SERA titers than those generated in mice immunized with the SERA DNA plasmid alone. Vaccination with DNA may provide a viable alternative or may be used in conjunction with protein-based subunit vaccines to maximize the efficacy of a human malaria vaccine that includes immunogenic regions of the SERA protein. PMID:10496891

  14. Immune responses induced by gene gun or intramuscular injection of DNA vaccines that express immunogenic regions of the serine repeat antigen from Plasmodium falciparum.

    PubMed

    Belperron, A A; Feltquate, D; Fox, B A; Horii, T; Bzik, D J

    1999-10-01

    The liver- and blood-stage-expressed serine repeat antigen (SERA) of Plasmodium falciparum is a candidate protein for a human malaria vaccine. We compared the immune responses induced in mice immunized with SERA-expressing plasmid DNA vaccines delivered by intramuscular (i.m.) injection or delivered intradermally by Gene Gun immunization. Mice were immunized with a pcdna3 plasmid encoding the entire 47-kDa domain of SERA (amino acids 17 to 382) or the N-terminal domain (amino acids 17 to 110) of SERA. Minimal antibody responses were detected following DNA vaccination with the N-terminal domain of SERA, suggesting that the N-terminal domain alone is not highly immunogenic by this route of vaccine delivery. Immunization of mice by Gene Gun delivery of the 47-kDa domain of SERA elicited a significantly higher serum antibody titer to the antigen than immunization of mice by i.m. injection with the same plasmid did. The predominant isotype subclass of the antibodies elicited to the SERA protein following i.m. and Gene Gun immunizations with SERA plasmid DNA was immunoglobulin G1. Coimmunization of mice with SERA plasmid DNA and a plasmid expressing the hepatitis B surface antigen (pCMV-s) by the i.m. route resulted in higher anti-SERA titers than those generated in mice immunized with the SERA DNA plasmid alone. Vaccination with DNA may provide a viable alternative or may be used in conjunction with protein-based subunit vaccines to maximize the efficacy of a human malaria vaccine that includes immunogenic regions of the SERA protein. PMID:10496891

  15. Screening of early antigen genes of adult-stage Trichinella spiralis using pig serum from different stages of early infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this work was to identify novel, early antigens present in Trichinella spiralis. To this end, a cDNA library generated from 3-day old adult worms (Ad3) was immunologically screened using serum from a pig infected with 20,000 muscle larvae. The serum was obtained from multiple, time cours...

  16. In vivo characterization of a prostate-specific antigen promoter-based suicide gene therapy for the treatment of benign prostatic hyperplasia.

    PubMed

    Park, H S; Cheon, J; Cho, H Y; Ko, Y H; Bae, J H; Moon, D G; Kim, J J

    2003-07-01

    To develop a novel gene therapeutic modality for the effective treatment of benign prostatic hyperplasia (BPH), we investigated the properties of toxic gene therapy utilizing prostate-specific antigen (PSA) promoter driving herpes simplex virus thymidine kinase (HSV-TK) suicide gene to induce highly selective molecular ablation of epithelial cells with minimal systemic toxicity in canine prostate. Replication-defective recombinant adenoviral vectors containing HSV-TK gene under transcriptional control of long PSA promoter (Ad-PSA-HSV-TK) were developed and delivered in an situ manner. Briefly, laparotomies were performed and Ad-PSA-HSV-TK (1 x 10(9) PFUs) was injected into the left lateral lobe of prostate only on days 1 and 7 with appropriate prodrug acyclovir in adult Beagle dogs. The therapeutic efficacy was evaluated on the 56th experimental day. The striking apoptosis of epithelial cells was identified in the treated left half of canine prostate on TUNEL assay. On immunohistochemical studies, there was markedly decreased number of PSA-secreting epithelial cells compared to control. Also significant atrophy of prostate glands, associated with dense infiltration of lymphocytes and plasma cells, was identified in the treated side. The PSA promoter-based suicide gene therapy induced highly selective and definite ablation of epithelial cells in benign canine prostate. Our novel approach could open opportunity of gene therapeutic modality for the treatment of clinical BPH. PMID:12808443

  17. Identification of the O antigen polymerase (rfc) gene in Escherichia coli O4 by insertional mutagenesis using a nonpolar chloramphenicol resistance cassette.

    PubMed Central

    Lukomski, S; Hull, R A; Hull, S I

    1996-01-01

    Computer analysis of the O4 polysaccharide gene cluster of Escherichia coli revealed the presence of two open reading frames (ORFs) encoding strongly hydrophobic polypeptides. O antigen polymerase, which is encoded by the rfc gene, is a potential membrane protein and therefore should be hydrophobic. To identify the rfc gene, these two ORFs were subjected to insertional mutagenesis. A chloramphenicol resistance cassette was designed which, when properly inserted, does not cause a polar effect in downstream genes. Each of two ORFs, cloned into a plasmid vector, was inactivated with this cassette. Two types of mutants bearing chromosomal insertions of the cassettes in each ORF were constructed by homologous recombination. These mutants were characterized by PCR, Southern blotting, and transverse-alternating-field electrophoresis. Only one class of mutants exhibited the expected O polymerase-deficient phenotype; they produced O4-specific, semirough lipopolysaccharide. Therefore, this ORF was identified as the rfc gene. The chromosomal rfc mutation was complemented in trans by the rfc gene expressed from a plasmid vector. PMID:8550424

  18. Structure elucidation and gene cluster annotation of the O-antigen of Escherichia coli O39; application of anhydrous trifluoroacetic acid for selective cleavage of glycosidic linkages.

    PubMed

    Perepelov, Andrei V; Filatov, Andrei V; Wang, Quan; L'vov, Vyacheslav L; Qian, Ye; Shashkov, Alexander S; Wang, Lei; Knirel, Yuriy A

    2014-03-31

    O-Polysaccharide (O-antigen) accompanied by a minor mannan was isolated from the lipopolysaccharide of Escherichia coli O39 and studied by component analyses, methylation, Smith degradation, mass spectrometry, and 1D and 2D NMR spectroscopy. In addition, a new approach, solvolysis with anhydrous trifluoroacetic acid, was applied to cleave selectively the rhamnosidic linkage. The following structure of the O-polysaccharide was established: α--D-Galpl-->3-->3)-β-D-Quip4N(R3Hb)-(1-->2)-α-D-Manp-(l-->4)-α-L-Rhap-(1-->3)-α-D-GlcpNAc-(1--> where D-Qui4N(R3Hb) indicates 4,6-dideoxy-4-[(R)-3-hydroxybutanoylamino]-d-glucose. The O-antigen gene cluster of E. coli O39 has been sequenced. The gene functions were tentatively assigned by a comparison with sequences in the available databases and found to be in agreement with the O-polysaccharide structure. PMID:24607538

  19. Clonally diverse rfb gene clusters are involved in expression of a family of related D-galactan O antigens in Klebsiella species.

    PubMed Central

    Kelly, R F; Whitfield, C

    1996-01-01

    Klebsiella species express a family of structurally related lipopolysaccharide O antigens which share a common backbone known as D-galactan I. Serotype specificity results from modification of D-galactan I by addition of domains of altered structure or by substitution with O-acetyl and/or alpha-D-Galp side groups with various linkages and stoichiometries. In the prototype, Klebsiella serotype O1, the his-linked rfb gene cluster is required for synthesis of D-galactan I, but genes conferring serotype specificity are unlinked. The D-galactan I part of the O polysaccharide is O acetylated in Klebsiella serotype O8. By cloning the rfb region from Klebsiella serotype O8 and analyzing the O polysaccharide synthesized in Escherichia coli K-12 hosts, we show that, like rfbO1, the rfbO8 region directs formation of unmodified D-galactan I. The rfbAB genes encode an ATP-binding cassette transporter required for export of polymeric D-galactan I across the plasma membrane prior to completion of the lipopolysaccharide molecule by ligation of the O polysaccharide to lipid A-core. Complementation experiments show that the rfbAB gene products in serotypes O1 and O8 are functionally equivalent and interchangeable. Hybridization experiments and physical mapping of the rfb regions in related Klebsiella serotypes suggest the existence of shared rfb genes with a common organization. However, despite the functional equivalence of these rfb gene clusters, at least three distinct clonal groups were detected in different Klebsiella species and subspecies, on the basis of Southern hybridization experiments carried out under high-stringency conditions. The clonal groups cannot be predicted by features of the O-antigen structure. To examine the relationships in more detail, the complete nucleotide sequence of the serotype O8 rfb cluster was determined and compared with that of the serotype O1 prototype. The nucleotide sequences for the six rfb genes showed variations in moles percent G

  20. Gene and antigen markers of Shiga-toxin producing E. coli from Michigan and Indiana river water: Occurrence and relation to recreational water quality criteria

    USGS Publications Warehouse

    Duris, J.W.; Haack, S.K.; Fogarty, L.R.

    2009-01-01

    The relation of bacterial pathogen occurrence to fecal indicator bacteria (FIB) concentrations used for recreational water quality criteria (RWQC) is poorly understood. This study determined the occurrence of Shiga-toxin producing Escherichia coli (STEC) markers and their relation to FIB concentrations in Michigan and Indiana river water. Using 67 fecal coliform (FC) bacteria cultures from 41 river sites in multiple watersheds, we evaluated the occurrence of five STEC markers: the Escherichia coli (EC) O157 antigen and gene, and the STEC virulence genes eaeA, stx1, and stx2. Simple isolations from selected FC cultures yielded viable EC O157. By both antigen and gene assays, EC O157 was detected in a greater proportion of samples exceeding rather than meeting FC RWQC (P < 0.05), but was unrelated to EC and enterococci RWQC. The occurrence of all other STEC markers was unrelated to any FIB RWQC. The eaeA, stx2, and stx1 genes were found in 93.3, 13.3, and in 46.7% of samples meeting FC RWQC and in 91.7, 0.0, and 37.5% of samples meeting the EC RWQC. Although not statistically significant, the percentage of samples positive for each STEC marker except stx1 was lower in samples that met, as opposed to exceeded, FIB RWQC. Viable STEC were common members of the FC communities in river water throughout southern Michigan and northern Indiana, regardless of FIB RWQC. Our study indicates that further information on the occurrence of pathogens in recreational waters, and research on alternative indicators of their occurrence, may help inform water-resource management and public health decision-making. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  1. Analysis of processing and polyadenylation signals of the hepatitis B virus surface antigen gene by using simian virus 40-hepatitis B virus chimeric plasmids

    SciTech Connect

    Simonsen, C.C.; Levinson, A.D.

    1983-12-01

    The authors examined the transcription of the hepatitis B virus surface antigen (HBsAg) gene in COs cells transfected with simian virus 40-based recombinant plasmids. When positioned behind the simian virus 40 late promoter, three transcripts were identified which hybridized to the HBsAg gene: a 2,000-nucleotide transcript colinear with a gene, a 1,100-nucleotide transcript representing a spliced molecule in which a major portion of the sequences encoding HBsAg were deleted, and an 800-nucleotide transcript derived primarily from sequences 3' to the HBsAg gene. The splice acceptor site utilized by the 1,100-nucleotide transcript is located immediately upstream of an open reading frame of unknown function contained within the 3' nontranslated region of the HBsAg gene. The HBsAg-specific mRNA species terminate 12 to 19 base pairs 3' of the sequence UAUAAA, similar to the concensus hexanucleotide which is thought to promote polyadenylation (AAUAAA). They constructed a series of plasmids with progressive deletions from the region surrounding where these transcripts terminate. Analysis of mRNA produced by cells transfected with these plasmids indicated that the signal hexanucleotide is in itself unable to promote the efficient processing of mRNA in the absence of downstream hepatitis B virus sequences. Processing proceeds properly, however, from plasmids containing an additional 30 nucleotides 3' of this signal.

  2. Polymorphisms within the human leucocyte antigen-E gene and their associations with susceptibility to rheumatoid arthritis as well as clinical outcome of anti-tumour necrosis factor therapy.

    PubMed

    Iwaszko, M; Świerkot, J; Kolossa, K; Jeka, S; Wiland, P; Bogunia-Kubik, K

    2015-12-01

    Involvement of the non-classical human leucocyte antigen-E (HLA-E) in both innate and acquired immune response suggests its possible role in development of autoimmune pathologies. This study was undertaken to investigate relationships between the HLA-E gene single nucleotide polymorphisms (SNPs) and a risk of rheumatoid arthritis (RA), as well as to evaluate a potential of these polymorphisms to modulate clinical outcome of anti-tumour necrosis factor (TNF) treatment in female patients. A total of 223 female patients with RA receiving anti-TNF biological therapy and 134 female healthy subjects were enrolled into the study. Genotypings for two SNPs within the HLA-E gene (rs1264457 HLA-E*01:01/01:03; rs1059510 HLA-E*01:03:01/01:03:02) were performed using a polymerase chain reaction (PCR) amplification employing LightSNiP assays. Clinical response was evaluated according to the European League Against Rheumatism (EULAR) criteria at 12 and 24 weeks after initiation of the therapy. The frequency of the HLA-E*01:01/01:01 genotype was decreased significantly in RA patients in comparison to controls (P = 0.031). The presence of the HLA-E*01:01/01:01 genotype in patients correlated with better EULAR response after 12 weeks of anti-TNF treatment, while 01:03 allele carriers were generally unresponsive to the treatment (P = 0.014). The HLA-E*01:03/01:03 genotype was also over-represented among non-responding patients in comparison to HLA-E*01:01/01:01 homozygotes (P = 0.021). With respect to the HLA-E rs1059510 variation, a better response after 12 weeks was observed more frequently in patients carrying the HLA-E*01:03:01/01:03:01 genotype than other genotypes (P = 0.009). The results derived from this study imply that HLA-E polymorphisms may influence RA susceptibility and affect clinical outcome of anti-TNF therapy in female RA patients. PMID:26307125

  3. Organization of the V gene segments in mouse T-cell antigen receptor [alpha]/[delta] locus

    SciTech Connect

    Wang, K.; Klotz, J.L.; Kiser, G.; Bristol, G.; Hays, E.; Lai, E.; Gese, E.; Kronenberg, M.; Hood, L. )

    1994-04-01

    The mouse T-cell receptor (TCR) [alpha]/[delta] was mapped using 17 V[alpha] and 4 V[delta] subfamily-specific probes. Four complementary methods were used: (1) an estimate of the V gene repertoire by Southern blot analysis of genomic DNA with subfamily-specific probes; (2) an analysis of V gene segments deleted by TCR gene rearrangements from a panel of T-cell tumors and hybridomas; (3) an analysis of overlapping clusters of cosmid clones; and (4) an analysis of large DNA fragments separated by field-inversion gel electrophoresis. The [alpha]/[delta] locus spans about 1 Mb. The distance between the 3[prime]-most V gene segments (V[delta]1) and the [delta] constant gene (C[delta]) is no more than 150 kb. Sixty-six V gene segments have been mapped physically on cosmids. The members of individual V[alpha] gene segments subfamilies are dispersed throughout the locus. In contrast, the V[delta] gene segments V[delta]1 to 5 are clustered at the 3[prime] end of the V gene segments cluster. At least two DNA segment duplications, 45 to 80 kb in length, are present in the locus. These data provide information on the evolution of the [alpha]/[delta] locus and on organizational features that might influence the expression of specific V gene segments in [gamma][delta] cells. 35 refs., 5 figs., 2 tabs.

  4. Influence of Cationic Lipid Composition on Gene Silencing Properties of Lipid Nanoparticle Formulations of siRNA in Antigen-Presenting Cells

    PubMed Central

    Basha, Genc; Novobrantseva, Tatiana I; Rosin, Nicole; Tam, Yuen Yi C; Hafez, Ismail M; Wong, Matthew K; Sugo, Tsukasa; Ruda, Vera M; Qin, June; Klebanov, Boris; Ciufolini, Marco; Akinc, Akin; Tam, Ying K; Hope, Michael J; Cullis, Pieter R

    2011-01-01

    Lipid nanoparticles (LNPs) are currently the most effective in vivo delivery systems for silencing target genes in hepatocytes employing small interfering RNA. Antigen-presenting cells (APCs) are also potential targets for LNP siRNA. We examined the uptake, intracellular trafficking, and gene silencing potency in primary bone marrow macrophages (bmMΦ) and dendritic cells of siRNA formulated in LNPs containing four different ionizable cationic lipids namely DLinDAP, DLinDMA, DLinK-DMA, and DLinKC2-DMA. LNPs containing DLinKC2-DMA were the most potent formulations as determined by their ability to inhibit the production of GAPDH target protein. Also, LNPs containing DLinKC2-DMA were the most potent intracellular delivery agents as indicated by confocal studies of endosomal versus cytoplamic siRNA location using fluorescently labeled siRNA. DLinK-DMA and DLinKC2-DMA formulations exhibited improved gene silencing potencies relative to DLinDMA but were less toxic. In vivo results showed that LNP siRNA systems containing DLinKC2-DMA are effective agents for silencing GAPDH in APCs in the spleen and peritoneal cavity following systemic administration. Gene silencing in APCs was RNAi mediated and the use of larger LNPs resulted in substantially reduced hepatocyte silencing, while similar efficacy was maintained in APCs. These results are discussed with regard to the potential of LNP siRNA formulations to treat immunologically mediated diseases. PMID:21971424

  5. Protein encoded by HSV-1 stimulation-related gene 1 (HSRG1) interacts with and inhibits SV40 large T antigen.

    PubMed

    Guo, H X; Cun, W; Liu, L D; Dong, S Z; Wang, L C; Dong, C H; Li, Q H

    2006-12-01

    Herpes simplex virus (HSV)-1 stimulation-related gene 1 (HSRG1) protein expression is induced in HSV-1 infected cells. We found that HSRG1 interacts with SV40 large T antigen (LT) in yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) assay. This interaction alters LT's regulation of the SV40 promoter and its ability to influence the cell cycle. Choramphenicol acetyl-transferase (CAT) assays revealed that initiation of gene transcription by LT is changed by HSRG1 expression. HSRG1 inhibits the ability of LT to activate SV40 late gene transcription. Further data indicate that the ability of LT protein to stimulate S-phase entry is also inhibited by the expression of HSRG1. The results of a colony-forming assay suggested that expression of HSRG1 in cells transfected by LT gene decreased the rate of colony formation. Yeast two-hybrid beta-galactosidase assay revealed that amino acid residues 132-450 in LT bind HSRG1. PMID:17109635

  6. Analysis of stage-specific transcripts of the Plasmodium falciparum serine repeat antigen (SERA) gene and transcription from the SERA locus.

    PubMed

    Fox, B A; Bzik, D J

    1994-11-01

    We evaluated the stage-specific transcription and processing of serine repeat antigen (SERA) messenger RNA to further examine mechanisms regulating gene expression in Plasmodium falciparum. SERA mRNA was expressed exclusively in trophozoite and schizont stages. Transcription from the SERA gene was first detected between 24 and 29 h following erythrocyte invasion. The transcript mapping data revealed heterogeneity of the SERA mRNA 5' and 3' ends. RNA sequencing revealed that SERA transcripts were not generated by a trans-splicing mechanism. A new SERA gene, SERA3, was identified 1.8 kb upstream of SERA. The direction of transcription of the SERA locus genes, SERA3, SERA, and SERA2, was mapped relative to the location of other chromosome 2 genetic markers. The SERA locus and the closely linked MSA2 locus were found to be transcriptionally regulated in a coordinate fashion. Collectively, the results of these experiments show that parallel and coordinately controlled transcription units reside on chromosome 2. These results implicate a novel mechanism of transcriptional control in Plasmodium. PMID:7891737

  7. Organization of the gene (RHCE) encoding the human blood group RhCcEe antigens and characterization of the promoter region

    SciTech Connect

    Cherif-Zahar, B.; Le Van Kim, C.; Rouillac, C.; Raynal, V.; Cartron, J.P.; Colin, Y. )

    1994-01-01

    The human RH (rhesus) locus is composed of two genes, RHD and RHCE, encoding the D, Cc, and Ee blood group antigens. The RHCE gene was isolated from a human genomic library and characterized. It is organized into 10 exons distributed over 75 kb. Exons 4-8 are alternatively spliced in the different RNA isoforms previously identified. Primer extension analysis indicated that the transcription initiation site is located 83 bp upstream of the initiation codon. The 5[prime] flanking region of the RHCE gene, from nucleotide [minus]600 to +42, exhibited a significant transcriptional activity after transfection in the erythroleukemic cell line K562, but not in the nonhematopoietic cell line HeLa. This result was in agreement with Northern blot analysis, suggesting that the expression of the RH locus is restricted to the erythroid/megakaryocytic lineage. Accordingly, putative binding sites for SP1, GATA-1, and Ets proteins, nuclear factors known to be involved in the erythroid and megakaryocytic gene expression, were identified in this Rh promoter. 36 refs., 5 figs., 1 tab.

  8. Glucagon gene 5'-flanking sequences direct expression of simian virus 40 large T antigen to the intestine, producing carcinoma of the large bowel in transgenic mice.

    PubMed

    Lee, Y C; Asa, S L; Drucker, D J

    1992-05-25

    Glucagon and the glucagon-like peptides play important roles in the regulation of glucose homeostasis. Previous studies have demonstrated that approximately 1300 base pairs of rat glucagon gene 5'-flanking sequences direct transgene expression to the pancreas and brain, but not to the intestine, of transgenic mice. These observations suggested that different tissue-specific enhancer elements mediate activation of glucagon gene transcription in the pancreas and intestine. We have now generated mice that express SV40 large T antigen under the control of approximately 2000 base pairs of glucagon gene 5'-flanking sequences. Transgene expression was observed in the brain and pancreas in association with the development of pancreatic endocrine tumors. In contrast to the mice described previously, we also detected transgene expression throughout the gastrointestinal tract in endocrine cells of the stomach and small and large intestine. Focal areas of enteroendocrine cell hyperplasia in the large bowel invariably progressed to invasive and metastasizing plurihormonal endocrine carcinoma, which was clinically and pathologically evident by 4 weeks of age. In contrast, transgene expression in the small bowel and stomach was not associated with progression to either hyperplasia or carcinoma. The results of these studies provide functional evidence for the existence of an upstream cis-acting regulatory domain that directs glucagon gene transcription to the endocrine cells of the intestine in transgenic mice. PMID:1587847

  9. The role of B. pertussis vaccine antigen gene variants in pertussis resurgence and possible consequences for vaccine development.

    PubMed

    Preston, Andrew

    2016-05-01

    Whooping cough, or pertussis, caused by Bordetella pertussis is considered resurgent in a number of countries world-wide, despite continued high level vaccine coverage. Among a number of causes for this that have been proposed, is the emergence of B. pertussis strains expressing variants of the antigens contained in acellular pertussis vaccines; i.e. the evolution of B. pertussis toward vaccine escape. This commentary highlights the contradictory nature of evidence for this but also discusses the importance of understanding the role of B. pertussis adaptation to vaccine-mediated immune selection pressures for vaccine-mediated pertussis control strategies. PMID:26889694

  10. The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters

    PubMed Central

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca; Kukavica-Ibrulj, Irena; Boyle, Brian; Laroche, Jérôme; Pirnay, Jean-Paul; Lévesque, Roger C.

    2015-01-01

    ABSTRACT The O-specific antigen (OSA) in Pseudomonas aeruginosa lipopolysaccharide is highly varied by sugar identity, side chains, and bond between O-repeats. These differences classified P. aeruginosa into 20 distinct serotypes. In the past few decades, O12 has emerged as the predominant serotype in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how the P. aeruginosa OSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83 P. aeruginosa strains and their serotypes. While most serotypes were closely linked to the core genome phylogeny, we observed horizontal exchange of OSA biosynthesis genes among phylogenetically distinct P. aeruginosa strains. Specifically, we identified a “serotype island” ranging from 62 kb to 185 kb containing the P. aeruginosa O12 OSA gene cluster, an antibiotic resistance determinant (gyrAC248T), and other genes that have been transferred between P. aeruginosa strains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related to P. aeruginosa PA7. Acquisition and recombination of the “serotype island” resulted in displacement of the native OSA gene cluster and expression of the O12 serotype in the recipients. Serotype switching by recombination has apparently occurred multiple times involving bacteria of various genomic backgrounds. In conclusion, serotype switching in combination with acquisition of an antibiotic resistance determinant most likely contributed to the dissemination of the O12 serotype in clinical settings. PMID:26396243

  11. Selecting soluble/foldable protein domains through single-gene or genomic ORF filtering: structure of the head domain of Burkholderia pseudomallei antigen BPSL2063.

    PubMed

    Gourlay, Louise J; Peano, Clelia; Deantonio, Cecilia; Perletti, Lucia; Pietrelli, Alessandro; Villa, Riccardo; Matterazzo, Elena; Lassaux, Patricia; Santoro, Claudio; Puccio, Simone; Sblattero, Daniele; Bolognesi, Martino

    2015-11-01

    The 1.8 Å resolution crystal structure of a conserved domain of the potential Burkholderia pseudomallei antigen and trimeric autotransporter BPSL2063 is presented as a structural vaccinology target for melioidosis vaccine development. Since BPSL2063 (1090 amino acids) hosts only one conserved domain, and the expression/purification of the full-length protein proved to be problematic, a domain-filtering library was generated using β-lactamase as a reporter gene to select further BPSL2063 domains. As a result, two domains (D1 and D2) were identified and produced in soluble form in Escherichia coli. Furthermore, as a general tool, a genomic open reading frame-filtering library from the B. pseudomallei genome was also constructed to facilitate the selection of domain boundaries from the entire ORFeome. Such an approach allowed the selection of three potential protein antigens that were also produced in soluble form. The results imply the further development of ORF-filtering methods as a tool in protein-based research to improve the selection and production of soluble proteins or domains for downstream applications such as X-ray crystallography. PMID:26527140

  12. Structural Integrity of the Antigen Is a Determinant for the Induction of T-Helper Type-1 Immunity in Mice by Gene Gun Vaccines against E.coli Beta-Galactosidase

    PubMed Central

    Deressa, Tekalign; Stoecklinger, Angelika; Wallner, Michael; Himly, Martin; Kofler, Stefan; Hainz, Katrina; Brandstetter, Hans; Thalhamer, Josef; Hammerl, Peter

    2014-01-01

    The type of immune response is critical for successful protection and typically determined by pathogen-associated danger molecules. In contrast, protein antigens are usually regarded as passive target structures. Here, we provide evidence that the structure of the antigen can profoundly influence the type of response that is elicited under else identical conditions. In mice, gene gun vaccines induce predominantly Th2-biased immune reactions against most antigens. One exception is E. coli beta-galactosidase (βGal) that induces a balanced Th1/Th2 response. Because both, the delivered material (plasmid DNA-coated gold particles) as well as the procedure (biolistic delivery to the skin surface) is the same as for other antigens we hypothesized that Th1 induction could be a function of βGal protein expressed in transfected cells. To test this we examined gene gun vaccines encoding structural or functional variants of the antigen. Employing a series of gene gun vaccines encoding individual structural domains of βGal, we found that neither of them induced IgG2a antibodies. Even disruption of the homo-tetramer association of the native protein by deletion of a few N-terminal amino acids was sufficient to abrogate IgG2a production. However, enzymatically inactive βGal with only one point mutation in the catalytic center retained the ability to induce Th1 reactions. Thus, structural but not functional integrity of the antigen must be retained for Th1 induction. βGal is not a Th1 adjuvant in the classical sense because neither were βGal-transgenic ROSA26 mice particularly Th1-biased nor did co-administration of a βGal-encoding plasmid induce IgG2a against other antigens. Despite this, gene gun vaccines elicited Th1 reactions to antigens fused to the open reading frame of βGal. We interpret these findings as evidence that different skin-borne antigens may be differentially handled by the immune system and that the three-dimensional structure of an antigen is an

  13. Differential transcription of two highly divergent gut-expressed Bm86 antigen gene homologues in the tick Rhipicephalus appendiculatus (Acari: Ixodida).

    PubMed

    Kamau, L; Skilton, R A; Odongo, D O; Mwaura, S; Githaka, N; Kanduma, E; Obura, M; Kabiru, E; Orago, A; Musoke, A; Bishop, R P

    2011-02-01

    The transcriptional control of gene expression is not well documented in the Arthropoda. We describe transcriptional analysis of two exceptionally divergent homologues (Ra86) of the Bm86 gut antigen from Rhipicephalus appendiculatus. Bm86 forms the basis of a commercial vaccine for the control of Rhipicephalus (Boophilus) microplus. The R. appendiculatus Ra86 proteins contain 654 and 693 amino acids, with only 80% amino acid sequence identity. Reverse-transcription PCR of gut cDNA showed transcription of only one genotype in individual female ticks. PCR amplification of 3' untranslated sequences from genomic DNA indicated that both variants could be encoded within a single genome. When both variants were present, one of the two Ra86 genotypes was transcriptionally dominant. PMID:20854482

  14. Characterization Based on the 56-Kda Type-Specific Antigen Gene of Orientia tsutsugamushi Genotypes Isolated from Leptotrombidium Mites and the Rodent Host Post-Infection

    PubMed Central

    Takhampunya, Ratree; Tippayachai, Bousaraporn; Promsathaporn, Sommai; Leepitakrat, Surachai; Monkanna, Taweesak; Schuster, Anthony L.; Melendrez, Melanie C.; Paris, Daniel H.; Richards, Allen L.; Richardson, Jason H.

    2014-01-01

    Characterization of the 56-kDa type-specific antigen (TSA) genes of Orientia tsutsugamushi (OT) from three naturally infected, laboratory-reared mite colonies comprising three species (Leptotrombidium deliense [Ld], Leptotrombidium imphalum [Li], and Leptotrombidium chiangraiensis [Lc]) has revealed the presence of single and coexisting OT genotypes found in individual chiggers. The Karp genotype was found in all of the chiggers examined, whereas Gilliam and UT302 genotypes were only observed in combination with the Karp genotype. From analysis of these OT genotypes after transmission from chiggers to mice it was determined that with the Lc and Li mites, the OT genotype composition in the rodent spleens post-infection had not changed and therefore resembled that observed in the feeding chiggers. However, only the Karp genotype was found in rodents after feeding by Ld chiggers carrying Karp and Gilliam genotypes. The current findings reveal a complex association among the host, pathogen, and vector. PMID:24297814

  15. High-resolution structure of HLA-A*0201 in complex with a tumour-specific antigenic peptide encoded by the MAGE-A4 gene.

    PubMed

    Hillig, R C; Coulie, P G; Stroobant, V; Saenger, W; Ziegler, A; Hülsmeyer, M

    2001-07-27

    The heterotrimeric complex of the human major histocompatibity complex (MHC) molecule HLA-A*0201, beta2-microglobulin and the decameric peptide GVYDGREHTV derived from the melanoma antigen (MAGE-A4 protein has been determined by X-ray crystallography at 1.4 A resolution. MAGE-A4 belongs to a family of genes that are specifically expressed in a variety of tumours. MAGE-A4-derived peptides are presented by MHC molecules at the cell surface to cytotoxic T-lymphocytes. As the HLA-A*0201:MAGE-A4 complex occurs only on tumour cells, it is considered to be an appropriate target for immunotherapy. The structure presented here reveals potential epitopes specific to the complex and indicates which peptide residues could be recognised by T-cell receptors. In addition, as the structure could be refined anisotropically, it was possible to describe the movements of the bound peptide in more detail. PMID:11502003

  16. Identification and characterization of T-cell antigen receptor-related genes in phylogenetically diverse vertebrate species.

    PubMed

    Rast, J P; Haire, R N; Litman, R T; Pross, S; Litman, G W

    1995-01-01

    Characterization of the structure, multiplicity, organization, and cell lineage-specific expression of T-cell receptor (TCR) genes of nonmammalian vertebrate species is central to the understanding of the evolutionary origins of rearranging genes of the vertebrate immune system. We recently described a polymerase chain reaction (PCR) strategy that relies on short sequence similarities shared by nearly all vertebrate TCR and immunoglobulin (Ig) variable (V) regions and have used this approach to isolate a TCR beta (TCRB) homolog from a cartilaginous fish. Using these short PCR products as probes in spleen cDNA and genomic libraries, we were able to isolate a variety of unique TCR and TCR-like genes. Here we report the identification and characterization of a chicken TCR gamma (TCRG) homolog, apparent Xenopus and pufferfish TCR alpha (TCRA) homologs, and two horned shark TCR delta (TCRD)-like genes. In addition, we have identified what could be a novel representative of the Ig gene superfamily in the pufferfish. This method of using short, minimally degenerate PCR primers should speed progress in the phylogenetic investigations of the TCR and related genes and lend important insights into both the origins and functions of these unique gene systems. PMID:7642232

  17. Lack of association between cytotoxic T-lymphocyte antigen-4 gene polymorphisms and lymphoid malignancy risk: evidence from a meta-analysis.

    PubMed

    Dai, Zhiming; Feng, Chuanjie; Zhang, Wanggang; Liu, Jie; Cao, Xingmei; Zhang, Hui; Liu, Yuhong; Wang, Meng; Liu, Xinghan; Dai, Zhijun

    2016-10-01

    Cytotoxic T-lymphocyte antigen-4 (CTLA-4) polymorphisms have been associated with susceptibility to lymphoid malignancies. However, results from the published single studies are inconsistent. Therefore, the present meta-analysis was conducted to get a more accurate estimation of the relationship between CTLA-4 gene polymorphisms and the lymphoid malignancy risk. We identified nine independent studies accounting for 3090 subjects up to January 30, 2016. Summary odds ratios (OR) and 95 % confidence intervals (CI) were used to evaluate the risk of lymphoid malignancies. Overall, no significant association was found between +49A/G (rs231775), -318C/T (rs5742909), and +6230A/G (rs3087243) CTLA-4 gene polymorphisms and lymphoid malignancies. Furthermore, ethnicity (Asian and Caucasian) and histopathology subgroup analyses (non-Hodgkin's lymphoma) also failed to detect an association between the studied polymorphisms and lymphoid malignancy risk. Our study shows that common CTLA-4 gene polymorphisms may not contribute to lymphoid malignancy susceptibility based on the current evidence. PMID:27498821

  18. Association of cytotoxic T lymphocyte-associated antigen 4 gene single nucleotide polymorphism with type 1 diabetes mellitus in Madurai population of Southern India

    PubMed Central

    Philip, Beatrice; Isabel, W.

    2011-01-01

    Type 1 diabetes mellitus formerly called juvenile diabetes, is an organ specific T-cell mediated autoimmune disease characterized by the progressive loss of function of the insulin producing beta–cells of the islets of Langerhans. Cytotoxic T lymphocyte-associated antigen 4 gene (CTLA-4) has been proposed as a candidate gene for conferring susceptibility to autoimmunity. Association of CTLA-4 gene polymorphism is well established in autoimmune endocrinopathies across world population. The present study was conducted to investigate the association of CTLA-4 exon 1 49A/G polymorphism with TIDM in Madurai, a city in Southern India. Fifty three clinically proven T1DM patients and 53 control subjects with no history of autoimmune disease were recruited for the study. Genomic DNA was extracted from peripheral blood. CTLA-4 exon 1 49 A/G polymorphism was assessed using PCR-RFLP methods. Our findings revealed a significant association of CTLA-4 exon 1 49 A/G polymorphism with T1DM in Madurai population. PMID:22090719

  19. Association of polymorphisms of the transporter associated with antigen processing (TAP2) gene with pulmonary tuberculosis in an elderly Japanese population.

    PubMed

    Thu, Kaung Si; Sato, Noriko; Ikeda, Shinobu; Naka-Mieno, Makiko; Arai, Tomio; Mori, Seijiro; Sawabe, Motoji; Muramatsu, Masaaki; Tanaka, Masashi

    2016-08-01

    The transporter associated with antigen processing 2 (TAP2) gene is involved in the immunological response to tuberculosis (TB) infection. Variations in the TAP2 gene have been associated with TB infection in small population studies in India, Columbia, and Korea. We investigated the association of TAP2 polymorphisms with TB susceptibility in an elderly Japanese population. We analyzed samples from consecutive autopsy cases (n = 1850) registered in the Japanese Geriatric SNP Research database. TB was diagnosed pathologically by TB granuloma on autopsy samples. There were 289 cases and 1529 controls. Twenty-four single nucleotide variations (SNVs), including four missense variations in the TAP2 region, were genotyped using the Illumina Infinium Human Exome BeadChip array. Of the 24 SNVs in the TAP2 gene, rs4148871, rs4148876 (R651C), and rs2857103 showed statistically significant associations with TB susceptibility, and rs4148871 and rs2857103 also showed significant genotypic associations in a dominant allele model adjusted for age, sex, and smoking. Haplotype analysis showed that TAP2 allele *0103 conferred an increased TB risk (OR = 1.48, p = 0.0008), while the TAP2 *0201 allele was protective against TB (OR = 0.73, p = 0.0007). Our results suggest that TAP2 polymorphisms influence TB susceptibility in a Japanese population. PMID:27325005

  20. Characterization of cis-acting elements regulating transcription of the human DF3 breast carcinoma-associated antigen (MUC1) gene.

    PubMed Central

    Abe, M; Kufe, D

    1993-01-01

    The present studies have examined the sequences responsible for regulating transcription of the human DF3 breast carcinoma-associated antigen (MUC1) gene. A region 1656 base pairs upstream to the DF3 transcription initiation site was fused to the chloramphenicol acetyltransferase gene. Transient expression assays using a series of deleted constructs demonstrated that the region from position -618 contains the regulatory sequences necessary for DF3 transcription in human MCF-7 breast cancer cells. Further analysis with internal deletion vectors and heterologous promoter constructs indicated the involvement of cis-acting elements in the fragment extending from positions -598 to -485. By gel retardation and DNA footprinting, we have identified a protein in MCF-7 cells that recognizes sequences between positions -505 and -485. The results of Southwestern studies demonstrate that this protein has an apparent molecular mass of 45 kDa. Taken together, these results suggest that DF3 gene transcription is regulated by a previously undescribed transacting factor. Images PMID:8419933

  1. The African buffalo parasite Theileria. sp. (buffalo) can infect and immortalize cattle leukocytes and encodes divergent orthologues of Theileria parva antigen genes.

    PubMed

    Bishop, R P; Hemmink, J D; Morrison, W I; Weir, W; Toye, P G; Sitt, T; Spooner, P R; Musoke, A J; Skilton, R A; Odongo, D O

    2015-12-01

    African Cape buffalo (Syncerus caffer) is the wildlife reservoir of multiple species within the apicomplexan protozoan genus Theileria, including Theileria parva which causes East coast fever in cattle. A parasite, which has not yet been formally named, known as Theileria sp. (buffalo) has been recognized as a potentially distinct species based on rDNA sequence, since 1993. We demonstrate using reverse line blot (RLB) and sequencing of 18S rDNA genes, that in an area where buffalo and cattle co-graze and there is a heavy tick challenge, T. sp. (buffalo) can frequently be isolated in culture from cattle leukocytes. We also show that T. sp. (buffalo), which is genetically very closely related to T. parva, according to 18s rDNA sequence, has a conserved orthologue of the polymorphic immunodominant molecule (PIM) that forms the basis of the diagnostic ELISA used for T. parva serological detection. Closely related orthologues of several CD8 T cell target antigen genes are also shared with T. parva. By contrast, orthologues of the T. parva p104 and the p67 sporozoite surface antigens could not be amplified by PCR from T. sp. (buffalo), using conserved primers designed from the corresponding T. parva sequences. Collectively the data re-emphasise doubts regarding the value of rDNA sequence data alone for defining apicomplexan species in the absence of additional data. 'Deep 454 pyrosequencing' of DNA from two Theileria sporozoite stabilates prepared from Rhipicephalus appendiculatus ticks fed on buffalo failed to detect T. sp. (buffalo). This strongly suggests that R. appendiculatus may not be a vector for T. sp. (buffalo). Collectively, the data provides further evidence that T. sp. (buffalo). is a distinct species from T. parva. PMID:26543804

  2. The African buffalo parasite Theileria. sp. (buffalo) can infect and immortalize cattle leukocytes and encodes divergent orthologues of Theileria parva antigen genes

    PubMed Central

    Bishop, R.P.; Hemmink, J.D.; Morrison, W.I.; Weir, W.; Toye, P.G.; Sitt, T.; Spooner, P.R.; Musoke, A.J.; Skilton, R.A.; Odongo, D.O.

    2015-01-01

    African Cape buffalo (Syncerus caffer) is the wildlife reservoir of multiple species within the apicomplexan protozoan genus Theileria, including Theileria parva which causes East coast fever in cattle. A parasite, which has not yet been formally named, known as Theileria sp. (buffalo) has been recognized as a potentially distinct species based on rDNA sequence, since 1993. We demonstrate using reverse line blot (RLB) and sequencing of 18S rDNA genes, that in an area where buffalo and cattle co-graze and there is a heavy tick challenge, T. sp. (buffalo) can frequently be isolated in culture from cattle leukocytes. We also show that T. sp. (buffalo), which is genetically very closely related to T. parva, according to 18s rDNA sequence, has a conserved orthologue of the polymorphic immunodominant molecule (PIM) that forms the basis of the diagnostic ELISA used for T. parva serological detection. Closely related orthologues of several CD8 T cell target antigen genes are also shared with T. parva. By contrast, orthologues of the T. parva p104 and the p67 sporozoite surface antigens could not be amplified by PCR from T. sp. (buffalo), using conserved primers designed from the corresponding T. parva sequences. Collectively the data re-emphasise doubts regarding the value of rDNA sequence data alone for defining apicomplexan species in the absence of additional data. ‘Deep 454 pyrosequencing’ of DNA from two Theileria sporozoite stabilates prepared from Rhipicephalus appendiculatus ticks fed on buffalo failed to detect T. sp. (buffalo). This strongly suggests that R. appendiculatus may not be a vector for T. sp. (buffalo). Collectively, the data provides further evidence that T. sp. (buffalo). is a distinct species from T. parva. PMID:26543804

  3. Identification of genes coding for B cell antigens of Mycoplasma mycoides subsp. mycoides Small Colony (MmmSC) by using phage display

    PubMed Central

    2009-01-01

    Background Contagious bovine pleuropneumonia (CBPP) is a mycoplasmal disease caused by Mycoplasma mycoides subsp. mycoides SC (MmmSC). Since the disease is a serious problem that can affect cattle production in parts of Africa, there is a need for an effective and economical vaccine. Identifying which of the causative agent's proteins trigger potentially protective immune responses is an important step towards developing a subunit vaccine. Accordingly, the purpose of this study was to determine whether phage display combined with bioinformatics could be used to narrow the search for genes that code for potentially immunogenic proteins of MmmSC. Since the production of IgG2 and IgA are associated with a Th1 cellular immune response which is implicated in protection against CBPP, antigens which elicit these immunoglobulin subclasses may be useful in developing a subunit vaccine. Results A filamentous phage library displaying a repertoire of peptides expressed by fragments of the genome of MmmSC was constructed. It was subjected to selection using antibodies from naturally- and experimentally-infected cattle. Mycoplasmal genes were identified by matching the nucleotide sequences of DNA from immunoselected phage particles with the mycoplasmal genome. This allowed a catalogue of genes coding for the proteins that elicited an immune response to be compiled. Using this method together with computer algorithms designed to score parameters that influence surface accessibility and hence potential antigenicity, five genes (abc, gapN, glpO, lppB and ptsG) were chosen to be expressed in Escherichia coli. After appropriate site-directed mutagenesis, polypeptides representing portions of each of these proteins were tested for immunoreactivity. Of these five, polypeptides representing expression products of abc and lppB were recognised on immunoblots by sera obtained from cattle during a natural outbreak of the disease. Conclusion Since phage display physically couples phenotype

  4. Mutation of a Salmonella Serogroup-C1-Specific Gene Abrogates O7-Antigen Biosynthesis and Triggers NaCl-Dependent Motility Deficiency

    PubMed Central

    Zhou, Xiujuan; Liu, Bin; Shi, Chunlei; Shi, Xianming

    2014-01-01

    Several molecular detection marker genes specific for a number of individual Salmonella serogroups have been recently identified in our lab by comparative genomics for the genotyping of diverse serogroups. To further understand the correlation between serotype and genotype, the function of a Salmonella serogroup-C1-specific gene (SC_2092) was analyzed in this study. It was indicated from the topological prediction using the deduced amino acid sequence of SC_2092 that this putative protein was highly similar to the confirmed Wzx flippases. Furthermore, SDS-PAGE revealed that lipopolysaccharide (LPS) biosynthesis, specifically O-antigen synthesis, was incomplete in an SC_2092 in-frame deletion mutant, and no agglutination reaction with the O7 antibody was exhibited in this mutant. Therefore, it was revealed that this Salmonella serogroup-C1-specific gene SC_2092 encoded a putative flippase, which was required for O7-polysaccharide biosynthesis, and was designated here as wzxC1. Subsequently, the effects of the deletion of wzxC1 on bacterial motility and sodium chloride (NaCl) tolerance were evaluated. The wzxC1 mutant lacked swarming motility on solid surfaces and was impaired in swimming motility in soft agar. Moreover, microscopic examination and RT-qPCR exhibited that an increased auto-aggregation and a strong defect in flagella expression, respectively, were responsible for the reduced motility in this mutant. In addition, the wzxC1 mutant was more sensitive than the wild-type strain to NaCl, and auto-aggregation of mutant cells was observed immediately up on the addition of 1% NaCl to the medium. Interestingly, the motility deficiency of the mutant strain, as well as the cell agglomeration and the decrease in flagellar expression, were relieved in a NaCl-free medium. This is the first study to experimentally demonstrate a connection between a Salmonella serogroup specific gene identified by comparative genomics with the synthesis of a specific O-antigen

  5. Genomic Analyses, Gene Expression and Antigenic Profile of the Trans-Sialidase Superfamily of Trypanosoma cruzi Reveal an Undetected Level of Complexity

    PubMed Central

    Rodrigues-Luiz, Gabriela F.; Mendes, Tiago A. O.; Rodrigues, Thiago S.; Gazzinelli, Ricardo T.; Teixeira, Santuza M. R.; Fujiwara, Ricardo T.; Bartholomeu, Daniella C.

    2011-01-01

    The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection. PMID:22039427

  6. Use of antibody gene library for the isolation of specific single chain antibodies by ampicillin-antigen conjugates.

    PubMed

    Neumann-Schaal, Meina; Messerschmidt, Katrin; Grenz, Nicole; Heilmann, Katja

    2013-03-01

    Isolation of recombinant antibodies from antibody libraries is commonly performed by different molecular display formats including phage display and ribosome display or different cell-surface display formats. We describe a new method which allows the selection of Escherichia coli cells producing the required single chain antibody by cultivation in presence of ampicillin conjugated to the antigen of interest. The method utilizes the neutralization of the conjugate by the produced single chain antibody which is secreted to the periplasm. Therefore, a new expression system based on the pET26b vector was designed and a library was constructed. The method was successfully established first for the selection of E. coli BL21 Star (DE3) cells expressing a model single chain antibody (anti-fluorescein) by a simple selection assay on LB-agar plates. Using this selection assay, we could identify a new single chain antibody binding biotin by growing E. coli BL21 Star (DE3) containing the library in presence of a biotin-ampicillin conjugate. In contrast to methods as molecular or cell surface display our selection system applies the soluble single chain antibody molecule and thereby avoids undesired effects, e.g. by the phage particle or the yeast fusion protein. By selecting directly in an expression strain, production and characterization of the selected single chain antibody is possible without any further cloning or transformation steps. PMID:23453960

  7. [The antibodies to neurohormonal anti-genes as a criterion of early diagnostic and neurointoxication in workers of chemical enterprises].

    PubMed

    Bodienkova, G M; Alekseev, R Iu

    2014-11-01

    The examination was applied to enterprise workers laboring in conditions of vinyl chloride (79 patients), caustic soda (24 patients) and 10 patients with professional chronic mercury intoxication. The differences are established concerning manifestation of autoimmune reactions of personnel working in conditions of chronic effecting of vinyl chloride distinct of parameters characterizing autoimmune reactions of personnel working under impact of another neuro-toxicants (vapors of metallic mercury). The increasing of auto-antibodies to MAG was detected in healthy personnel and increasing of concentrations of auto-antibodies to protein S-100 and DNA was detected in personnel with initial manifestations of neuro-intoxication. These occurrences testify availability, of different mechanisms underlying formation of neurological disorders. The study data confirms involvement of auto-antibodies to neuronal antigens into derangement of neural activity in personnel working in conditions of effect of vinyl chloride and vapors of metallic mercury. Hence, the new possibilities are opened in studying pathogenesis of occupational neuro-intoxications. The detection of auto-antibodies to proteins of neural tissue can be recommended as a criterion of early identification of damage of neural system in personnel working in conditions of chemical industry. PMID:25850246

  8. Clonality Analysis of Immunoglobulin Gene Rearrangement by Next-Generation Sequencing in Endemic Burkitt Lymphoma Suggests Antigen Drive Activation of BCR as Opposed to Sporadic Burkitt Lymphoma

    PubMed Central

    Amato, Teresa; Abate, Francesco; Piccaluga, Pierpaolo; Iacono, Michele; Fallerini, Chiara; Renieri, Alessandra; De Falco, Giulia; Ambrosio, Maria Raffaella; Mourmouras, Vaselious; Ogwang, Martin; Calbi, Valeria; Rabadan, Roul; Hummel, Michael; Pileri, Stefano; Bellan, Cristiana

    2016-01-01

    Objectives: Recent studies using next-generation sequencing (NGS) analysis disclosed the importance of the intrinsic activation of the B-cell receptor (BCR) pathway in the pathogenesis of sporadic Burkitt lymphoma (sBL) due to mutations of TCF3/ID3 genes. Since no definitive data are available on the genetic landscape of endemic Burkitt (eBL), we first assessed the mutation frequency of TCF3/ID3 in eBL compared with sBL and subsequently the somatic hypermutation status of the BCR to answer whether an extrinsic activation of BCR signaling could also be demonstrated in Burkitt lymphoma. Methods: We assessed the mutations of TCF3/ID3 by RNAseq and the BCR status by NGS analysis of the immunoglobulin genes (IGs). Results: We detected mutations of TCF3/ID3 in about 30% of the eBL cases. This rate is significantly lower than that detected in sBL (64%). The NGS analysis of IGs revealed intraclonal diversity, suggesting an active targeted somatic hypermutation process in eBL compared with sBL. Conclusions: These findings support the view that the antigenic pressure plays a key role in the pathogenetic pathways of eBL, which may be partially distinct from those driving sBL development. PMID:26712879

  9. Molecular cloning and sequence analysis of the gene coding for the 57-kDa major soluble antigen of the salmonid fish pathogen Renibacterium salmoninarum.

    PubMed

    Chien, M S; Gilbert, T L; Huang, C; Landolt, M L; O'Hara, P J; Winton, J R

    1992-09-15

    The complete sequence coding for the 57-kDa major soluble antigen of the salmonid fish pathogen, Renibacterium salmoninarum, was determined. The gene contained an opening reading frame of 1671 nucleotides coding for a protein of 557 amino acids with a calculated M(r) value of 57,190. The first 26 amino acids constituted a signal peptide. The deduced sequence for amino acid residues 27-61 was in agreement with the 35 N-terminal amino acid residues determined by microsequencing, suggesting the protein is synthesized as a 557-amino acid precursor and processed to produce a mature protein of M(r) 54,505. Two regions of the protein contained imperfect direct repeats. The first region contained two copies of an 81-residue repeat, the second contained five copies of an unrelated 25-residue repeat. Also, a perfect inverted repeat (including three in-frame UAA stop codons) was observed at the carboxyl-terminus of the gene. PMID:1383085

  10. pH-sensitive polymer-liposome-based antigen delivery systems potentiated with interferon-γ gene lipoplex for efficient cancer immunotherapy.

    PubMed

    Yuba, Eiji; Kanda, Yuhei; Yoshizaki, Yuta; Teranishi, Ryoma; Harada, Atsushi; Sugiura, Kikuya; Izawa, Takeshi; Yamate, Jyoji; Sakaguchi, Naoki; Koiwai, Kazunori; Kono, Kenji

    2015-10-01

    Potentiation of pH-sensitive liposome-based antigen carriers with IFN-γ gene lipoplexes was attempted to achieve efficient induction of tumor-specific immunity. 3-Methylglutarylated poly(glycidol) (MGluPG)-modified liposomes and cationic liposomes were used, respectively, for the delivery of antigenic protein ovalbumin (OVA) and IFN-γ-encoding plasmid DNA (pDNA). The MGluPG-modified liposomes and the cationic liposome-pDNA complexes (lipoplexes) formed hybrid complexes via electrostatic interactions after their mixing in aqueous solutions. The hybrid complexes co-delivered OVA and IFN-γ-encoding pDNA into DC2.4 cells, a murine dendritic cell line, as was the case of MGluPG-modified liposomes for OVA or the lipoplexes for pDNA. Both the lipoplexes and the hybrid complexes transfected DC2.4 cells and induced IFN-γ protein production, but transfection activities of the hybrid complexes were lower than those of the parent lipoplexes. Subcutaneous administration of hybrid complexes to mice bearing E.G7-OVA tumor reduced tumor volumes, which might result from the induction of OVA-specific cytotoxic T lymphocytes (CTLs). However, the hybrid complex-induced antitumor effect was the same level of the MGluPG-modified liposome-mediated antitumor immunity. In contrast, an extremely strong antitumor immune response was derived when these liposomes and lipoplexes without complexation were injected subcutaneously at the same site of tumor-bearing mice. Immunohistochemical analysis of tumor sections revealed that immunization through the liposome-lipoplex combination promoted the infiltration of CTLs to tumors at an early stage of treatment compared with liposomes, resulting in strong therapeutic effects. PMID:26222284

  11. The vls antigenic variation systems of Lyme disease Borrelia: eluding host immunity through both random, segmental gene conversion and framework heterogeneity

    PubMed Central

    Norris, Steven J.

    2015-01-01

    Summary Spirochetes that cause Lyme borreliosis (also called Lyme disease) possess the vls locus, encoding an elaborate antigenic variation system. This locus contains the expression site vlsE as well as a contiguous array of vls silent cassettes, which contain variations of the central cassette region of vlsE. The locus is present on one of the many linear plasmids in the organism, e.g. plasmid lp28-1 in the strain B. burgdorferi B31. Changes in the sequence of vlsE occur continuously during mammalian infection and consist of random, segmental, unidirectional recombination events between the silent cassettes and the cassette region of vlsE. These gene conversion events do not occur during in vitro culture or the tick portion of the infection cycle of Borrelia burgdorferi or the other related Borrelia species that cause Lyme disease. The mechanism of recombination is largely unknown, but requires the RuvAB Holliday junction branch migrase. Other features of the vls locus also appear to be required, including cis locations of vlsE and the silent cassettes and high G+C content and GC skew. The vls system is required for long-term survival of Lyme Borrelia in infected mammals and represents an important mechanism of immune evasion. In addition to sequence variation, immune selection also results in significant heterogeneity in the sequence of the surface lipoprotein VlsE. Despite antigenic variation, VlsE generates a robust antibody response, and both full length VlsE and the C6 peptide (corresponding to invariant region 6) are widely used in immunodiagnostic tests for Lyme disease. PMID:26104445

  12. Feline immunodeficiency virus reverse transcriptase: expression, functional characterization, and reconstitution of the 66- and 51-kilodalton subunits.

    PubMed Central

    Amacker, M; Hottiger, M; Hübscher, U

    1995-01-01

    The two subunits of the feline immunodeficiency virus (FIV) reverse transcriptase (RT) were cloned and functionally expressed in Escherichia coli. The recombinant proteins are enzymatically active as homodimers (p66 and p51) as well as a heterodimer p66/p51. The biochemical properties of the FIV RT are very similar to those of the counterpart of the human immunodeficiency virus type 1 in being an RNA-dependent and DNA-dependent DNA polymerase. When a double-stranded DNA containing a small gap of 26 nucleotides was tested, we found a new activity of the FIV RT p66/p51 heterodimer--the cat viral enzyme could perform strand displacement DNA synthesis of approximately 300 bases. The FIV RT homodimer p66 alone could carry out limited strand displacement DNA synthesis, but this activity was stimulated by the p51 subunit at a molar ratio of one molecule of p66 to five molecules of p51. On the other hand, the homodimeric p51 itself was unable to fill a small gap of 26 nucleotides in a double-stranded DNA substrate and was not active by itself in strand displacement DNA synthesis. These data are in agreement with an earlier finding of strand displacement DNA synthesis by human immunodeficiency virus type 1 RT (M. Hottiger, V.N. Podust, R.L. Thimmig, C.S. McHenry, and U. Hübscher. J. Biol. Chem. 269:986-991, 1994). Our data therefore suggest a general and important function of lentiviral p51 subunits in strand displacement DNA synthesis which appears to be required in later stages of the lentiviral replication cycle, when DNA-dependent DNA synthesis occurs on double-stranded DNA. PMID:7545246

  13. Mutation and Recombination in the Upstream Homology Box-Flanked ospE-Related Genes of the Lyme Disease Spirochetes Result in the Development of New Antigenic Variants during Infection

    PubMed Central

    Sung, Shian Ying; McDowell, John V.; Carlyon, Jason A.; Marconi, Richard T.

    2000-01-01

    The ospE gene family of the Lyme disease spirochetes encodes a polymorphic group of immunogenic lipoproteins. The ospE genes are one of several gene families that are flanked by a highly conserved upstream sequence called the upstream homology box, or UHB, element. Earlier analyses in our lab demonstrated that ospE-related genes are characterized by defined hypervariable domains (domains 1 and 2) that are predicted to be hydrophilic, surface exposed, and antigenic. The flanking of hypervariable domain 1 by DNA repeats may indicate that recombination contributes to ospE diversity and thus ultimately to antigenic variation. Using an isogeneic clone of Borrelia burgdorferi B31G (designated B31Gc1), we demonstrate that the ospE-related genes undergo mutation and rearrangement during infection in mice. The mutations that develop during infection resulted in the generation of OspE proteins with altered antigenic characteristics. The data support the hypothesized role of OspE-related proteins in immune system evasion. PMID:10678944

  14. Contribution of allelic variability in prostate specific antigen (PSA) & androgen receptor (AR) genes to serum PSA levels in men with prostate cancer

    PubMed Central

    Chavan, Sushant V.; Maitra, Anurupa; Roy, Nobhojit; Chavan, Padma R.

    2014-01-01

    Background & objectives: Wide variability in serum prostate specific antigen (PSA) levels exists in malignant conditions of the prostate. PSA is expressed in normal range in 20 to 25 per cent of prostate cancer cases even in presence of high grade Gleason score. This study was aimed to assess the influence of genetic variants exhibited by PSA and androgen receptor (AR) genes towards the variable expression of PSA in prostate cancer. Methods: Pre-treatment serum PSA levels from 101 prostate cancer cases were retrieved from medical record. PSA genotype analysis in promoter region and AR gene microsatellite Cytosine/Adenine/Guanine (CAG) repeat analysis in exon 1 region was performed using DNA sequencing and fragment analysis techniques. Results: A total of seven single nucleotide polymorphisms (SNPs) in the PSA promoter region were noted. Only two SNPs viz., 158G/A (P<0.001) in the proximal promoter region and -3845G/A (P<0.001) in enhancer region showed significant association with serum PSA levels. The carriers of homozygous GG genotype (P<0.001) at both of these polymorphic sites showed higher expression of PSA whereas homozygous AA genotype (P<0.001) carriers demonstrated lower PSA levels. The combination effect of PSA genotypes along with stratified AR CAG repeats lengths (long, intermediate and short) was also studied. The homozygous GG genotype along with AR long CAG repeats and homozygous AA genotype along with AR short CAG repeats at position -3845 and -158 showed strong interaction and thus influenced serum PSA levels. Interpretation & conclusions: The genetic variants exhibited by PSA gene at positions -3845G/A and -158G/A may be accountable towards wide variability of serum PSA levels in prostate cancer. Also the preferential binding of G and A alleles at these polymorphic sites along with AR long and short CAG repeats may contribute towards PSA expression. PMID:24820830

  15. Genetic diversity of the Plasmodium falciparum apical membrane antigen I gene in parasite population from the China-Myanmar border area.

    PubMed

    Zhu, Xiaotong; Zhao, Zhenjun; Feng, Yonghui; Li, Peipei; Liu, Fei; Liu, Jun; Yang, Zhaoqing; Yan, Guiyun; Fan, Qi; Cao, Yaming; Cui, Liwang

    2016-04-01

    To investigate the genetic diversity of the Plasmodium falciparum apical membrane antigen 1 (PfAMA1) gene in Southeast Asia, we determined PfAMA1 sequences from 135 field isolates collected from the China-Myanmar border area and compared them with 956 publically available PfAMA1 sequences from seven global P. falciparum populations. This analysis revealed high genetic diversity of PfAMA1 in global P. falciparum populations with a total of 229 haplotypes identified. The genetic diversity of PfAMA1 gene from the China-Myanmar border is not evenly distributed in the different domains of this gene. Sequence diversity in PfAMA1 from the China-Myanmar border is lower than that observed in Thai, African and Oceanian populations, but higher than that in the South American population. This appeared to correlate well with the levels of endemicity of different malaria-endemic regions, where hyperendemic regions favor genetic cross of the parasite isolates and generation of higher genetic diversity. Neutrality tests show significant departure from neutrality in the entire ectodomain and Domain I of PfAMA1 in the China-Myanmar border parasite population. We found evidence supporting a substantial continent-wise genetic structure among P. falciparum populations, with the highest genetic differentiation detected between the China-Myanmar border and the South American populations. Whereas no alleles were unique to a specific region, there were considerable geographical differences in major alleles and their frequencies, highlighting further necessity to include more PfAMA1 alleles in vaccine designs. PMID:26825252

  16. Attempts to enhance cross-protection against porcine reproductive and respiratory syndrome viruses using chimeric viruses containing structural genes from two antigenically distinct strains.

    PubMed

    Sun, Dong; Khatun, Amina; Kim, Won-Il; Cooper, Vickie; Cho, Yong-Il; Wang, Chong; Choi, Eun-Jin; Yoon, Kyoung-Jin

    2016-08-01

    Due to significant antigenic variations between field isolates of porcine reproductive and respiratory syndrome virus (PRRSV), suboptimal cross-protection between different viruses impedes the effective control of PRRS via vaccination. Our previous study showed that chimeric viruses containing mixed structural genes from two distinct strains (VR2332 and JA142) of PRRSV were highly susceptible to the viral neutralizing activity of antisera generated against both parental strains. In this study, three chimeric viruses (JAP5, JAP56 and JAP2-6) were constructed by replacing ORF5, ORFs 5 and 6, and ORFs 2-6 of VR2332 with the corresponding genes of JA142, respectively, and their ability to confer cross-protection against challenge with the VR2332 and JA142 strains was evaluated in vivo. A total of 114 pigs were divided into 6 groups, and each group was intramuscularly injected with one of the 3 chimeric viruses (n=16 pigs per group), VR2332 (n=24), JA142 (n=24), or sham inoculum (n=18). At 44days post-inoculation (dpi), these pigs were further divided into 15 groups (n=6 or 8 pigs per group) and intranasally challenged with VR2332, JA142, or sham inoculum. All pigs inoculated with one of the chimeric viruses prior to challenge had lower viremia levels than the challenge control pigs. Prior inoculation with JAP56 markedly decreased viremia to nearly undetectable levels in pigs challenged with either VR2332 or JA142. These results suggest that chimeric viruses harboring mixed structural genes from two distinct PRRSV strains can provide protection against both donor viruses. PMID:27406935

  17. Molecular evolution of a central region containing B cell epitopes in the gene encoding the p67 sporozoite antigen within a field population of Theileria parva.

    PubMed

    Obara, Isaiah; Ulrike, Seitzer; Musoke, Tony; Spooner, Paul R; Jabbar, Ahmed; Odongo, David; Kemp, Stephen; Silva, Joana C; Bishop, Richard P

    2015-05-01

    Protective immunity induced by the infective sporozoite stage of Theileria parva indicates a potential role for antibodies directed against conserved serologically reactive regions of the major sporozoite surface antigen p67 in vaccination to control the parasite. We have examined the allelic variation and determined the extent of B cell epitope polymorphism of the gene encoding p67 among field isolates originating from cattle exposed to infected ticks in the Marula area of the rift valley in central Kenya where the African cape buffalo (Syncerus caffer) and cattle co-graze. In the first of two closely juxtaposed epitope sequences in the central region of the p67 protein, an in-frame deletion of a seven-amino acid segment results in a truncation that was observed in parasites derived from cattle that co-grazed with buffalo. In contrast, the variation in the second epitope was primarily due to nonsynonymous substitutions, resulting in relatively low overall amino acid conservation in this segment of the protein. We also observed polymorphism in the region of the protein adjacent to the two defined epitopes, but this was not sufficient to provide statistically significant evidence for positive selection. The data indicates that B cell epitopes previously identified within the p67 gene are polymorphic within the Marula field isolates. Given the complete sequence identity of the p67 gene in all previously characterized T. parva isolates that are transmissible between cattle by ticks, the diversity observed in p67 from the Marula isolates in combination with the clinical reaction of the infected cattle is consistent with them originating from ticks that had acquired T. parva from buffalo. PMID:25673078

  18. Interacting Alleles of the Coinhibitory Immunoreceptor Genes Cytotoxic T-Lymphocyte Antigen 4 and Programmed Cell-Death 1 Influence Risk and Features of Primary Biliary Cirrhosis

    PubMed Central

    Juran, Brian D.; Atkinson, Elizabeth J.; Schlicht, Erik M.; Fridley, Brooke L.; Petersen, Gloria M.; Lazaridis, Konstantinos N.

    2012-01-01

    Autoimmune diseases such as primary biliary cirrhosis (PBC) result from failure in the immune mechanisms that establish and maintain self-tolerance. Evidence suggests that these processes are shared among the spectrum of autoimmune syndromes and are likely genetically determined. Cytotoxic T-lymphocyte antigen 4 (CTLA4) and programmed cell-death 1 (PDCD1) are two genes encoding coinhibitory immunoreceptors that harbor polymorphisms with demonstrated associations to multiple autoimmune disorders. We aimed to assess functional single nucleotide polymorphisms (SNPs) in these two genes for association with PBC. SNPs in CTLA4 and PDCD1 were genotyped in 351 PBC patients and 205 controls. Allele and genotype frequencies were evaluated for association with PBC and/or antimitochondrial antibody (AMA) positivity with logistic regression. Haplotypes were inferred with an expectation-maximization algorithm, and allelic interaction was analyzed by logistic regression modeling. Individual SNPs demonstrated no association to PBC. However, the GG genotype of CTLA4 49AG was significantly associated with AMA positivity among the PBC patients. Also, individual SNPs and a haplotype of CTLA4 as well as a rare genotype of the PDCD1 SNP PD1.3 were associated with orthotopic liver transplantation. As well, we identified the influence of an interaction between the putatively autoimmune-protective CTLA4 49AG:CT60 AA haplotype and autoimmune-risk PDCD1 PD1.3 A allele on development of PBC. Conclusion Our findings illustrate the complex nature of the genetically induced risk of PBC and emphasize the importance of considering definable subphenotypes of disease, such as AMA positivity, or definitive measures of disease severity/progression, like orthotopic liver transplantation, when genetic analyses are being performed. Comprehensive screening of genes involved with immune function will lead to a greater understanding of the genetic component of autoimmunity in PBC while furthering our

  19. O Acetylation of the Enterobacterial Common Antigen Polysaccharide Is Catalyzed by the Product of the yiaH Gene of Escherichia coli K-12▿

    PubMed Central

    Kajimura, Junko ; Rahman, Arifur; Hsu, James; Evans, Matthew R.; Gardner, Kevin H.; Rick, Paul D.

    2006-01-01

    The carbohydrate component of the enterobacterial common antigen (ECA) of Escherichia coli K-12 occurs primarily as a water-soluble cyclic polysaccharide located in the periplasm (ECACYC) and as a phosphoglyceride-linked linear polysaccharide located on the cell surface (ECAPG). The polysaccharides of both forms are comprised of the amino sugars N-acetyl-d-glucosamine (GlcNAc), N-acetyl-d-mannosaminuronic acid (ManNAcA), and 4-acetamido-4,6-dideoxy-d-galactose (Fuc4NAc). These amino sugars are linked to one another to form trisaccharide repeat units with the structure →3-α-d-Fuc4NAc-(1→4)-β-d-ManNAcA-(1→4)-α-d-GlcNAc-(1→. The hydroxyl group in the 6 position of the GlcNAc residues of both ECACYC and ECAPG are nonstoichiometrically esterified with acetyl groups. Random transposon insertion mutagenesis of E. coli K-12 resulted in the generation of a mutant defective in the incorporation of O-acetyl groups into both ECACYC and ECAPG. This defect was found to be due to an insertion of the transposon into the yiaH locus, a putative gene of unknown function located at 80.26 min on the E. coli chromosomal map. Bioinformatic analyses of the predicted yiaH gene product indicate that it is an integral inner membrane protein that is a member of an acyltransferase family of enzymes found in a wide variety of organisms. The results of biochemical and genetic experiments presented here strongly support the conclusion that yiaH encodes the O-acetyltransferase responsible for the incorporation of O-acetyl groups into both ECACYC and ECAPG. Accordingly, we propose that this gene be designated wecH. PMID:16936038

  20. DNA binding and antigene activity of a daunomycin-conjugated triplex-forming oligonucleotide targeting the P2 promoter of the human c-myc gene

    PubMed Central

    Carbone, Giuseppina M.; McGuffie, Eileen; Napoli, Sara; Flanagan, Courtney E.; Dembech, Chiara; Negri, Umberto; Arcamone, Federico; Capobianco, Massimo L.; Catapano, Carlo V.

    2004-01-01

    Triplex-forming oligonucleotides (TFO) that bind DNA in a sequence-specific manner might be used as selective repressors of gene expression and gene-targeted therapeutics. However, many factors, including instability of triple helical complexes in cells, limit the efficacy of this approach. In the present study, we tested whether covalent linkage of a TFO to daunomycin, which is a potent DNA-intercalating agent and anticancer drug, could increase stability of the triple helix and activity of the oligonucleotide in cells. The 11mer daunomycin-conjugated GT (dauno-GT11) TFO targeted a sequence upstream of the P2 promoter, a site known to be critical for transcription of the c-myc gene. Band-shift assays showed that the dauno-GT11 formed triplex DNA with enhanced stability compared to the unmodified TFO. Band shift and footprinting experiments demonstrated that binding of dauno-GT11 was highly sequence-specific with exclusive binding to the 11 bp target site in the c-myc promoter. The daunomycin-conjugated TFO inhibited transcription in vitro and reduced c-myc promoter activity in prostate and breast cancer cells. The daunomycin-conjugated TFO was taken up by cells with a distinctive intracellular distribution compared to free daunomycin. However, cationic lipid-mediated delivery was required for enhanced cellular uptake, nuclear localization and biological activity of the TFO in cells. Dauno-GT11 reduced transcription of the endogenous c-myc gene in cells, but did not affect expression of non-target genes, such as ets-1 and ets-2, which contained very similar target sequences in their promoters. Daunomycin-conjugated control oligonucleotides unable to form triplex DNA with the target sequence did not have any effect in these assays, indicating that daunomycin was not directly responsible for the activity of daunomycin-conjugated TFO. Thus, attachment of daunomycin resulted in increased triplex stability and biological activity of the 11mer GT-rich TFO without

  1. Association of Single Nucleotide Polymorphisms in the ST3GAL4 Gene with VWF Antigen and Factor VIII Activity.

    PubMed

    Song, Jaewoo; Xue, Cheng; Preisser, John S; Cramer, Drake W; Houck, Katie L; Liu, Guo; Folsom, Aaron R; Couper, David; Yu, Fuli; Dong, Jing-Fei

    2016-01-01

    VWF is extensively glycosylated with biantennary core fucosylated glycans. Most N-linked and O-linked glycans on VWF are sialylated. FVIII is also glycosylated, with a glycan structure similar to that of VWF. ST3GAL sialyltransferases catalyze the transfer of sialic acids in the α2,3 linkage to termini of N- and O-glycans. This sialic acid modification is critical for VWF synthesis and activity. We analyzed genetic and phenotypic data from the Atherosclerosis Risk in Communities (ARIC) study for the association of single nucleotide polymorphisms (SNPs) in the ST3GAL4 gene with plasma VWF levels and FVIII activity in 12,117 subjects. We also analyzed ST3GAL4 SNPs found in 2,535 subjects of 26 ethnicities from the 1000 Genomes (1000G) project for ethnic diversity, SNP imputation, and ST3GAL4 haplotypes. We identified 14 and 1,714 ST3GAL4 variants in the ARIC GWAS and 1000G databases respectively, with 46% being ethnically diverse in their allele frequencies. Among the 14 ST3GAL4 SNPs found in ARIC GWAS, the intronic rs2186717, rs7928391, and rs11220465 were associated with VWF levels and with FVIII activity after adjustment for age, BMI, hypertension, diabetes, ever-smoking status, and ABO. This study illustrates the power of next-generation sequencing in the discovery of new genetic variants and a significant ethnic diversity in the ST3GAL4 gene. We discuss potential mechanisms through which these intronic SNPs regulate ST3GAL4 biosynthesis and the activity that affects VWF and FVIII. PMID:27584569

  2. Complement gene variants in relation to autoantibodies to beta cell specific antigens and type 1 diabetes in the TEDDY Study.

    PubMed

    Törn, Carina; Liu, Xiang; Hagopian, William; Lernmark, Åke; Simell, Olli; Rewers, Marian; Ziegler, Anette-G; Schatz, Desmond; Akolkar, Beena; Onengut-Gumuscu, Suna; Chen, Wei-Min; Toppari, Jorma; Mykkänen, Juha; Ilonen, Jorma; Rich, Stephen S; She, Jin-Xiong; Sharma, Ashok; Steck, Andrea; Krischer, Jeffrey

    2016-01-01

    A total of 15 SNPs within complement genes and present on the ImmunoChip were analyzed in The Environmental Determinants of Diabetes in the Young (TEDDY) study. A total of 5474 subjects were followed from three months of age until islet autoimmunity (IA: n = 413) and the subsequent onset of type 1 diabetes (n = 115) for a median of 73 months (IQR 54-91). Three SNPs within ITGAM were nominally associated (p < 0.05) with IA: rs1143678 [Hazard ratio; HR 0.80; 95% CI 0.66-0.98; p = 0.032], rs1143683 [HR 0.80; 95% CI 0.65-0.98; p = 0.030] and rs4597342 [HR 1.16; 95% CI 1.01-1.32; p = 0.041]. When type 1 diabetes was the outcome, in DR3/4 subjects, there was nominal significance for two SNPs: rs17615 in CD21 [HR 1.52; 95% CI 1.05-2.20; p = 0.025] and rs4844573 in C4BPA [HR 0.63; 95% CI 0.43-0.92; p = 0.017]. Among DR4/4 subjects, rs2230199 in C3 was significantly associated [HR 3.20; 95% CI 1.75-5.85; p = 0.0002, uncorrected] a significance that withstood Bonferroni correction since it was less than 0.000833 (0.05/60) in the HLA-specific analyses. SNPs within the complement genes may contribute to IA, the first step to type 1 diabetes, with at least one SNP in C3 significantly associated with clinically diagnosed type 1 diabetes. PMID:27306948

  3. Complement gene variants in relation to autoantibodies to beta cell specific antigens and type 1 diabetes in the TEDDY Study

    PubMed Central

    Törn, Carina; Liu, Xiang; Hagopian, William; Lernmark, Åke; Simell, Olli; Rewers, Marian; Ziegler, Anette-G; Schatz, Desmond; Akolkar, Beena; Onengut-Gumuscu, Suna; Chen, Wei-Min; Toppari, Jorma; Mykkänen, Juha; Ilonen, Jorma; Rich, Stephen S.; She, Jin-Xiong; Sharma, Ashok; Steck, Andrea; Krischer, Jeffrey; Abbondondolo, Michael; Adams, Janey; Adamsson, Annika; Agardh, Daniel; Anderson, Stephen W.; Aronsson, Carin Andrén; Ask, Maria; Austin-Gonzalez, Sarah; Ayres, Stephen; Baethke, Sandra; Bautista, Kimberly; Baxter, Judith; Becker, Dorothy; Bedoy, Ruth; Bennet, Rasmus; Johnson, Suzanne Bennett; Beyerlein, Andreas; Bonifacio, Ezio; Bourcier, Kasia; Bremer, Jenny; Briese, Thomas; Brown, Rasheedah; Burkhardt, Brant; Butterworth, Martha; Carlsson, Ulla-Marie; Cilio, Corrado; Clasen, Joanna; Crouch, Claire Cowen; Cuthbertson, David; Daftary, Ashi; Dalmagro-Elias, MaryEllen; Dunson, Kayleen; Eberhard, Christopher; Larsson, Helena Elding; Ericsson-Hallström, Emelie; Felipe-Morales, Daniel; Fiske, Steven; Foghis, Gabriella; Foterek, Kristina; Fransiscus, Margaret; Fransson, Lina; Frohnert, Brigitte I.; Garcia, Dena; Gard, Thomas; Gardiner, Melissa; Garmeson, Jennifer; Gerardsson, Joanna; Gesualdo, Patricia; Gowda, Veena; Haller, Michael; Hansen, Monica; Hansson, Gertie; Harmby, Cecilia; Hervey, Rachel; Heyman, Kathleen; Hoffman, Michelle; Hopkins, Diane; Hummel, Michael; Hummel, Sandra; Hyberg, Susanne; Hyöty, Heikki; Johansen, Fredrik; Johnson, Corbin; Jokipuu, Sanna; Jonasdottir, Berglind; Kallio, Tiina; Karban, Rachel; Kersting, Mathilde; Killian, Michael; Klein, Beth; Knip, Mikael; Knopff, Annette; Koivu, Annika; Koletzko, Sibylle; Koreasalo, Mirva; Kurppa, Kalle; Kähönen, Miia; Lee, Hye-Seung; Forss, Sigrid Lenrick; Liu, Edwin; Liu, Shu; Lundgren, Markus; Lynch, Kristian; Lyons, Rachel; Lönnrot, Maria; Malloy, Jamie; Markan, Maria; McCarthy, Cristina; McIndoe, Richard; McLeod, Wendy; Melin, Jessica; Mestan, Zeliha; Meulemans, Steven; Meyer, Arlene; Mulenga, Denise; Multasuo, Katja; Månsson-Martinez, Maria; Mäntimäki, Elina; Niinien, Tiina; Norris, Jill; Nyblom, Mia; Peplow, Claudia; Laras, Francisco Perez; Rahmati, Kobra; Rajala, Petra; Ramelius, Anita; Rautanen, Jenna; Riikonen, Anne; Robinson, Richard; Romo, Minna; Rosenquist, Anna; Roth, Roswith; Salami, Falastin; Samper-Imaz, Adela; Scott, Elisabeth; Shaffer, Chris; Sibthorpe, Sara; Silvis, Katherine; Simell, Satu; Simell, Ville; Sjöberg, Maija; Sjöberg, Birgitta; Skidmore, Jennifer; Smith, Laura; Smith, Susan; Stabbert, Joshua; Steed, Leigh; Stenius, Aino; Stock, Joanna; Strauss, Elisabeth; Sulman, Noah; Swartling, Ulrica; Särmä, Maria; Tamura, Roy; Tarr, Alexander; Amboh, Evelyn Tekum; Thomas, Jamie; Triplett, Eric; Trulsson, Erika; Uland, Morgan; Uusitalo, Ulla; Vainionpää, Sini; Wallin, Anne; Varionen, Eeva; Warncke, Katharina; Waugh, Kathleen; Vehik, Kendra; Veijola, Riitta; Vijayakandipan, Ponni; Williams, Joshua; Willis, John; Wimar, Åsa; Winkler, Christiane; Virtanen, Suvi M.; Wood, Keith; Wright, Hali; Vähä-Mäkilä, Mari; Yang, Jimin; Yates, Chrystal; Åberg, Sofie; Åkerlund, Mari

    2016-01-01

    A total of 15 SNPs within complement genes and present on the ImmunoChip were analyzed in The Environmental Determinants of Diabetes in the Young (TEDDY) study. A total of 5474 subjects were followed from three months of age until islet autoimmunity (IA: n = 413) and the subsequent onset of type 1 diabetes (n = 115) for a median of 73 months (IQR 54–91). Three SNPs within ITGAM were nominally associated (p < 0.05) with IA: rs1143678 [Hazard ratio; HR 0.80; 95% CI 0.66–0.98; p = 0.032], rs1143683 [HR 0.80; 95% CI 0.65–0.98; p = 0.030] and rs4597342 [HR 1.16; 95% CI 1.01–1.32; p = 0.041]. When type 1 diabetes was the outcome, in DR3/4 subjects, there was nominal significance for two SNPs: rs17615 in CD21 [HR 1.52; 95% CI 1.05–2.20; p = 0.025] and rs4844573 in C4BPA [HR 0.63; 95% CI 0.43–0.92; p = 0.017]. Among DR4/4 subjects, rs2230199 in C3 was significantly associated [HR 3.20; 95% CI 1.75–5.85; p = 0.0002, uncorrected] a significance that withstood Bonferroni correction since it was less than 0.000833 (0.05/60) in the HLA-specific analyses. SNPs within the complement genes may contribute to IA, the first step to type 1 diabetes, with at least one SNP in C3 significantly associated with clinically diagnosed type 1 diabetes. PMID:27306948

  4. Intraperitoneal Administration of a Tumor-Associated Antigen SART3, CD40L, and GM-CSF Gene-Loaded Polyplex Micelle Elicits a Vaccine Effect in Mouse Tumor Models

    PubMed Central

    Furugaki, Kouichi; Cui, Lin; Kunisawa, Yumi; Osada, Kensuke; Shinkai, Kentaro; Tanaka, Masao; Kataoka, Kazunori; Nakano, Kenji

    2014-01-01

    Polyplex micelles have demonstrated biocompatibility and achieve efficient gene transfection in vivo. Here, we investigated a polyplex micelle encapsulating genes encoding the tumor-associated antigen squamous cell carcinoma antigen recognized by T cells-3 (SART3), adjuvant CD40L, and granulocyte macrophage colony-stimulating factor (GM-CSF) as a DNA vaccine platform in mouse tumor models with different types of major histocompatibility antigen complex (MHC). Intraperitoneally administrated polyplex micelles were predominantly found in the lymph nodes, spleen, and liver. Compared with mock controls, the triple gene vaccine significantly prolonged the survival of mice harboring peritoneal dissemination of CT26 colorectal cancer cells, of which long-term surviving mice showed complete rejection when re-challenged with CT26 tumors. Moreover, the DNA vaccine inhibited the growth and metastasis of subcutaneous CT26 and Lewis lung tumors in BALB/c and C57BL/6 mice, respectively, which represent different MHC haplotypes. The DNA vaccine highly stimulated both cytotoxic T lymphocyte and natural killer cell activities, and increased the infiltration of CD11c+ DCs and CD4+/CD8a+ T cells into tumors. Depletion of CD4+ or CD8a+ T cells by neutralizing antibodies deteriorated the anti-tumor efficacy of the DNA vaccine. In conclusion, a SART3/CD40L+GM-CSF gene-loaded polyplex micelle can be applied as a novel vaccine platform to elicit tumor rejection immunity regardless of the recipient MHC haplotype. PMID:25013909

  5. Prostate-associated gene 4 (PAGE4), an intrinsically disordered cancer/testis antigen, is a novel therapeutic target for prostate cancer.

    PubMed

    Kulkarni, Prakash; Dunker, A Keith; Weninger, Keith; Orban, John

    2016-01-01

    Prostate-associated gene 4 (PAGE4) is a remarkably prostate-specific Cancer/Testis Antigen that is highly upregulated in the human fetal prostate and its diseased states but not in the adult normal gland. PAGE4 is an intrinsically disordered protein (IDP) that functions as a stress-response protein to suppress reactive oxygen species as well as prevent DNA damage. In addition, PAGE4 is also a transcriptional regulator that potentiates transactivation by the oncogene c-Jun. c-Jun forms the AP-1 complex by heterodimerizing with members of the Fos family and plays an important role in the development and pathology of the prostate gland, underscoring the importance of the PAGE4/c-Jun interaction. HIPK1, also a component of the stress-response pathway, phosphorylates PAGE4 at T51 which is critical for its transcriptional activity. Phosphorylation induces conformational and dynamic switching in the PAGE4 ensemble leading to a new cellular function. Finally, bioinformatics evidence suggests that the PAGE4 mRNA could be alternatively spliced resulting in four potential isoforms of the polypeptide alluding to the possibility of a range of conformational ensembles with latent functions. Considered together, the data suggest that PAGE4 may represent the first molecular link between stress and prostate cancer (PCa). Thus, pharmacologically targeting PAGE4 may be a novel opportunity for treating and managing patients with PCa, especially patients with low-risk disease. PMID:27270343

  6. Evolution of the capsid protein genes of foot-and-mouth disease virus: antigenic variation without accumulation of amino acid substitutions over six decades.

    PubMed Central

    Martínez, M A; Dopazo, J; Hernández, J; Mateu, M G; Sobrino, F; Domingo, E; Knowles, N J

    1992-01-01

    The genetic diversification of foot-and-mouth disease virus (FMDV) of serotype C over a 6-decade period was studied by comparing nucleotide sequences of the capsid protein-coding regions of viruses isolated in Europe, South America, and The Philippines. Phylogenetic trees were derived for VP1 and P1 (VP1, VP2, VP3, and VP4) RNAs by using the least-squares method. Confidence intervals of the derived phylogeny (significance levels of nodes and standard deviations of branch lengths) were placed by application of the bootstrap resampling method. These procedures defined six highly significant major evolutionary lineages and a complex network of sublines for the isolates from South America. In contrast, European isolates are considerably more homogeneous, probably because of the vaccine origin of several of them. The phylogenetic analysis suggests that FMDV CGC Ger/26 (one of the earliest FMDV isolates available) belonged to an evolutionary line which is now apparently extinct. Attempts to date the origin (ancestor) of the FMDVs analyzed met with considerable uncertainty, mainly owing to the stasis noted in European viruses. Remarkably, the evolution of the capsid genes of FMDV was essentially associated with linear accumulation of silent mutations but continuous accumulation of amino acid substitutions was not observed. Thus, the antigenic variation attained by FMDV type C over 6 decades was due to fluctuations among limited combinations of amino acid residues without net accumulation of amino acid replacements over time. PMID:1316467

  7. Prostate-associated gene 4 (PAGE4), an intrinsically disordered cancer/testis antigen, is a novel therapeutic target for prostate cancer

    PubMed Central

    Kulkarni, Prakash; Dunker, A Keith; Weninger, Keith; Orban, John

    2016-01-01

    Prostate-associated gene 4 (PAGE4) is a remarkably prostate-specific Cancer/Testis Antigen that is highly upregulated in the human fetal prostate and its diseased states but not in the adult normal gland. PAGE4 is an intrinsically disordered protein (IDP) that functions as a stress-response protein to suppress reactive oxygen species as well as prevent DNA damage. In addition, PAGE4 is also a transcriptional regulator that potentiates transactivation by the oncogene c-Jun. c-Jun forms the AP-1 complex by heterodimerizing with members of the Fos family and plays an important role in the development and pathology of the prostate gland, underscoring the importance of the PAGE4/c-Jun interaction. HIPK1, also a component of the stress-response pathway, phosphorylates PAGE4 at T51 which is critical for its transcriptional activity. Phosphorylation induces conformational and dynamic switching in the PAGE4 ensemble leading to a new cellular function. Finally, bioinformatics evidence suggests that the PAGE4 mRNA could be alternatively spliced resulting in four potential isoforms of the polypeptide alluding to the possibility of a range of conformational ensembles with latent functions. Considered together, the data suggest that PAGE4 may represent the first molecular link between stress and prostate cancer (PCa). Thus, pharmacologically targeting PAGE4 may be a novel opportunity for treating and managing patients with PCa, especially patients with low-risk disease. PMID:27270343

  8. Nonviable mutants of simian virus 40 with deletions near the 3' end of gene A define a function for large T antigen required after onset of viral DNA replication.

    PubMed Central

    Tornow, J; Cole, C N

    1983-01-01

    Deletion mutants of simian virus 40 (SV40) with lesions at the three DdeI sites near the 3' end of the early region were constructed. Mutants with deletions at 0.203 and 0.219 map units (mu) which did not change the large T antigen reading frame were viable. This extends slightly the upstream boundary for the location of viable mutants with deletions in the 3' end of the A gene. Mutants with frameshift deletions at 0.193 and 0.219 mu were nonviable. These are the first nonviable mutants with deletions in this portion of the A gene. None of the three nonviable mutants with deletions at 0.219 mu produced progeny viral DNA. These three mutants all used the alternate reading frame located in this portion of the SV40 early region. The mutant with a deletion at 0.193 mu, dlA2459, was positive for viral DNA replication and was defective for adenovirus helper function. All of these mutations were located in the portion of the SV40 large T antigen which has no homology to the polyoma T antigens. These results indicate that this portion of large T antigen is required for some late step in the viral growth cycle and suggest that adenovirus helper function is required for productive infection by SV40. Images PMID:6312080

  9. Functional analysis and transcriptional regulation of porcine six transmembrane epithelial antigen of prostate 4 (STEAP4) gene and its novel variant in hepatocytes.

    PubMed

    Wang, S B; Lei, T; Zhou, L L; Zheng, H L; Zeng, C P; Liu, N; Yang, Z Q; Chen, X D

    2013-03-01

    Six-transmembrane epithelial antigen of prostate 4 (STEAP4) plays a critical role in modulating inflammatory response and protecting metabolic function. However, the role of STEAP4 in hepatocytes is not well understood, and the mechanism of STEAP4 action remains elusive. Here, we report the molecular characterization of porcine STEAP4 and its novel splice variant (STEAP4v), then the metabolic and anti-inflammatory roles of porcine STEAP4 and STEAP4v were investigated in HepG2 liver cells. The results revealed that overexpression of STEAP4, but not STEAP4v, suppresses triglyceride (TG) content and ameliorates the up-regulation of the transcription of the genes necessary for de novo lipogenesis and gluconeogenesis elicited by FFAs treatment. In RAW264.7 macrophage cells, transient transfection of STEAP4v, to a greater extent than STEAP4, repressed the transcription of TNFα and IL-6. In HepG2 cells with LPS treatment, the endogenous mRNA and protein levels of STEAP4 and STEAP4v were up-regulated, which was accompanied by a concurrent increase in C/EBPβ mRNA and protein levels. Thirdly, the functional regulation of STEAP4 was explored, which revealed that the porcine STEAP4 promoter activity was significantly up-regulated by C/EBPβ. The progressive deletions and mutations demonstrated that the C/EBPβ binding motif situated at -73/-59 bp is an essential component required for promoter activity of STEAP4 gene. Chromatin immunoprecipitation (ChIP) assays determined that C/EBPβ can directly interact with the steap4 promoter DNA. In conclusion, our data demonstrated that C/EBPβ directly regulates the roles of STEAP4 and its novel variant in attenuating lipogenesis, gluconeogenesis or/and inflammation elicited by FFAs or LPS in hepatocytes. PMID:23262293

  10. [Prokaryotic expression and antigenic activity analysis on the matrix protein genes of two strains of human metapneumovirus recently identified in Beijing].

    PubMed

    Cao, Shou-Chun; Qian, Yuan; Li, Guo-Hua; Zhu, Ru-Nan; Zhao, Lin-Qing; Ding, Ya-Xin

    2007-01-01

    Human metapneumovirus (hMPV) is a recently identified respiratory virus more like human respiratory syncytial virus in clinical symptoms. Matrix protein (M) is one of the most important structural proteins. For further studying of hMPV, the full length of M genes from the recombinant plasmid pUCm-M1816 and pUCmM1817 were cloned by PCR and sub-cloned into the pET30a(+) vector, which is a prokaryotic expression vector, after dual-enzyme digestion with Bam HI and Xho I. The positive recombinated plasmids were transformed into E. coli BL21 (DE3) and expressed under the inducing of IPTG. Target proteins were characterized by SDS-PAGE and Western blotting. In this article, we' ve successfully constructed the recombinated plasmids pET30a-M1816 and pET30a-M1817 which have correct open reading frames confirmed by dual-enzyme digestion analysis and sequencing. The fusion proteins with 6 x His-N were highly produced after inducing by 1mmol/ L IPTG at 37 degrees C. A unique protein band with approximate 27.6 kD was characterized by SDS-PAGE. Most of the target protein existed in inclusion body. Western blot analysis showed that the target protein has specific binding reaction to rabbit antiserum against polypeptides of the matrix protein of hMPV. So the M genes were highly expressed in the prokaryotic system and the expressed M proteins have specific antigenic activities. It can be used for further studying of hMPV infections in Beijing. PMID:17886723

  11. Purine twisted-intercalating nucleic acids: a new class of anti-gene molecules resistant to potassium-induced aggregation.

    PubMed

    Paramasivam, Manikandan; Cogoi, Susanna; Filichev, Vyacheslav V; Bomholt, Niels; Pedersen, Erik B; Xodo, Luigi E

    2008-06-01

    Sequence-specific targeting of genomic DNA by triplex-forming oligonucleotides (TFOs) is a promising strategy to modulate in vivo gene expression. Triplex formation involving G-rich oligonucleotides as third strand is, however, strongly inhibited by potassium-induced TFO self-association into G-quartet structures. We report here that G-rich TFOs with bulge insertions of (R)-1-O-[4-(1-pyrenylethynyl)-phenylmethyl] glycerol (called twisted intercalating nucleic acids, TINA) show a much lower tendency to aggregate in potassium than wild-type analogues do. We designed purine-motif TINA-TFOs for binding to a regulatory polypurine-polypyrimidine (pur/pyr) motif present in the promoter of the KRAS proto-oncogene. The binding of TINA-TFOs to the KRAS target has been analysed by electrophoresis mobility shift assays and DNase I footprinting experiments. We discovered that in the presence of potassium the wild-type TFOs did not bind to the KRAS target, differently from the TINA analogues, whose binding was observed up to 140 mM KCl. The designed TINA-TFOs were found to abrogate the formation of a DNA-protein complex at the pur/pyr site and to down-regulate the transcription of CAT driven by the murine KRAS promoter. Molecular modelling of the DNA/TINA-TFO triplexes are also reported. This study provides a new and promising approach to create TFOs to target in vivo the genome. PMID:18456705

  12. TCRs Used in Cancer Gene Therapy Cross-React with MART-1/Melan-A Tumor Antigens via Distinct Mechanisms

    SciTech Connect

    Borbulevych, Oleg Y.; Santhanagopolan, Sujatha M.; Hossain, Moushumi; Baker, Brian M.

    2013-09-18

    T cells engineered to express TCRs specific for tumor Ags can drive cancer regression. The first TCRs used in cancer gene therapy, DMF4 and DMF5, recognize two structurally distinct peptide epitopes of the melanoma-associated MART-1/Melan-A protein, both presented by the class I MHC protein HLA-A*0201. To help understand the mechanisms of TCR cross-reactivity and provide a foundation for the further development of immunotherapy, we determined the crystallographic structures of DMF4 and DMF5 in complex with both of the MART-1/Melan-A epitopes. The two TCRs use different mechanisms to accommodate the two ligands. Although DMF4 binds the two with a different orientation, altering its position over the peptide/MHC, DMF5 binds them both identically. The simpler mode of cross-reactivity by DMF5 is associated with higher affinity toward both ligands, consistent with the superior functional avidity of DMF5. More generally, the observation of two diverging mechanisms of cross-reactivity with the same Ags and the finding that TCR-binding orientation can be determined by peptide alone extend our understanding of the mechanisms underlying TCR cross-reactivity.

  13. Human Immunoglobulin (Ig)M+IgD+ Peripheral Blood B Cells Expressing the CD27 Cell Surface Antigen Carry Somatically Mutated Variable Region Genes: CD27 as a General Marker for Somatically Mutated (Memory) B Cells

    PubMed Central

    Klein, Ulf; Rajewsky, Klaus; Küppers, Ralf

    1998-01-01

    Immunoglobulin (Ig)M+IgD+ B cells are generally assumed to represent antigen-inexperienced, naive B cells expressing variable (V) region genes without somatic mutations. We report here that human IgM+IgD+ peripheral blood (PB) B cells expressing the CD27 cell surface antigen carry mutated V genes, in contrast to CD27-negative IgM+IgD+ B cells. IgM+IgD+CD27+ B cells resemble class-switched and IgM-only memory cells in terms of cell phenotype, and comprise ∼15% of PB B lymphocytes in healthy adults. Moreover, a very small population (<1% of PB B cells) of highly mutated IgD-only B cells was detected, which likely represent the PB counterpart of IgD-only tonsillar germinal center and plasma cells. Overall, the B cell pool in the PB of adults consists of ∼40% mutated memory B cells and 60% unmutated, naive IgD+CD27− B cells (including CD5+ B cells). In the somatically mutated B cells, VH region genes carry a two- to threefold higher load of somatic mutation than rearranged Vκ genes. This might be due to an intrinsically lower mutation rate in κ light chain genes compared with heavy chain genes and/or result from κ light chain gene rearrangements in GC B cells. A common feature of the somatically mutated B cell subsets is the expression of the CD27 cell surface antigen which therefore may represent a general marker for memory B cells in humans. PMID:9802980

  14. Cooperation between the polyomavirus Middle-T-antigen gene and the human c-myc oncogene in a rat thyroid epithelial differentiated cell line: Model of in vitro progression

    SciTech Connect

    Berlingieri, M.T.; Portella, G.; Grieco, M.; Santoro, M.; Fusco, A.

    1988-05-01

    Two rat thyroid epithelial differentiated cell lines, PC CI 3 and PC myc, were infected with the polyoma murine leukemia virus (PyMLV) carrying the Middle-T-antigen gene of polyomavirus. After infection, both cell lines acquired the typical markers of neoplastic transformation; however, the PC myc cells showed a greater malignant phenotype. Furthermore, the thyroid differentiated functions were completely suppressed in PC myc cells transformed by PyMLV, whereas they were, at least partially, retained in PC CI 3 cells transformed by PyMLV, and in particular, thyroglobulin synthesis and secretion were not affected at all. Since no differences in the expression of the middle-T-antigen gene were observed in the two PyMLV-transformed cell lines, the different properties shown by these two infected cell lines must be ascribed to the expression of the c-myc oncogene.

  15. Cooperation between the polyomavirus middle-T-antigen gene and the human c-myc oncogene in a rat thyroid epithelial differentiated cell line: model of in vitro progression.

    PubMed Central

    Berlingieri, M T; Portella, G; Grieco, M; Santoro, M; Fusco, A

    1988-01-01

    Two rat thyroid epithelial differentiated cell lines, PC Cl 3 and PC myc, were infected with the polyoma murine leukemia virus (PyMLV) carrying the Middle-T-antigen gene of polyomavirus. After infection, both cell lines acquired the typical markers of neoplastic transformation; however, the PC myc cells showed a greater malignant phenotype. Furthermore, the thyroid differentiated functions were completely suppressed in PC myc cells transformed by PyMLV, whereas they were, at least partially, retained in PC Cl 3 cells transformed by PyMLV, and in particular, thyroglobulin synthesis and secretion were not affected at all. Since no differences in the expression of the middle-T-antigen gene were observed in the two PyMLV-transformed cell lines, the different properties shown by these two infected cell lines must be ascribed to the expression of the c-myc oncogene. Images PMID:2838744

  16. Cutaneous antigen priming via gene gun leads to skin-selective Th2 immune-inflammatory responses.

    PubMed

    Alvarez, David; Harder, Greg; Fattouh, Ramzi; Sun, Jiangfeng; Goncharova, Susanna; Stämpfli, Martin R; Coyle, Anthony J; Bramson, Jonathan L; Jordana, Manel

    2005-02-01

    It is becoming increasingly evident that the compartmentalization of immune responses is governed, in part, by tissue-selective homing instructions imprinted during T cell differentiation. In the context of allergic diseases, the fact that "disease" primarily manifests in particular tissue sites, despite pervasive allergen exposure, supports this notion. However, whether the original site of Ag exposure distinctly privileges memory Th2 immune-inflammatory responses to the same site, while sparing remote tissue compartments, remains to be fully investigated. We examined whether skin-targeted delivery of plasmid DNA encoding OVA via gene-gun technology in mice could generate allergic sensitization and give rise to Th2 effector responses in the skin as well as in the lung upon subsequent Ag encounter. Our data show that cutaneous Ag priming induced OVA-specific serum IgE and IgG1, robust Th2-cytokine production, and late-phase cutaneous responses and systemic anaphylactic shock upon skin and systemic Ag recall, respectively. However, repeated respiratory exposure to aerosolized OVA failed to instigate airway inflammatory responses in cutaneous Ag-primed mice, but not in mice initially sensitized to OVA via the respiratory mucosa. Importantly, these contrasting airway memory responses correlated with the occurrence of Th2 differentiation events at anatomically separate sites: indeed cutaneous Ag priming resulted in Ag-specific proliferative responses and Th2 differentiation in skin-, but not thoracic-, draining lymph nodes. These data indicate that Ag exposure to the skin leads to Th2 differentiation within skin-draining lymph nodes and subsequent Th2 immunity that is selectively manifested in the skin. PMID:15661930

  17. Comparison of O-Antigen gene clusters of all O-Serogroups of Escherichia coli and proposal for adopting a new nomenclature for O-Typing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli strains are classified based on O-antigens that are components of the lipopolysaccharide (LPS) in the cell envelope. O-antigens are important virulence factors, targets of both the innate and adaptive immune system, and play a role in host-pathogen interaction. Because they are hi...

  18. Antigenically Modified Human Pluripotent Stem Cells Generate Antigen-Presenting Dendritic Cells

    PubMed Central

    Zeng, Jieming; Wu, Chunxiao; Wang, Shu

    2015-01-01

    Human pluripotent stem cells (hPSCs) provide a promising platform to produce dendritic cell (DC) vaccine. To streamline the production process, we investigated a unique antigen-loading strategy that suits this novel platform. Specifically, we stably modified hPSCs using tumour antigen genes in the form of a full-length tumour antigen gene or an artificial tumour antigen epitope-coding minigene. Such antigenically modified hPSCs were able to differentiate into tumour antigen-presenting DCs. Without conventional antigen-loading, DCs derived from the minigene-modified hPSCs were ready to prime a tumour antigen-specific T cell response and further expand these specific T cells in restimulation processes. These expanded tumour antigen-specific T cells were potent effectors with central memory or effector memory phenotype. Thus, we demonstrated that immunocompetent tumour antigen-loaded DCs can be directly generated from antigenically modified hPSCs. Using such strategy, we can completely eliminate the conventional antigen-loading step and significantly simplify the production of DC vaccine from hPSCs. PMID:26471005

  19. Deletion mutants that affect expression of Epstein-Barr virus nuclear antigen in COS-1 cells after gene transfer with simian virus 40 vectors containing portions of the BamHI K fragment.

    PubMed Central

    Polvino-Bodnar, M; Shedd, D; Miller, G

    1986-01-01

    We have identified sequences that affect the efficient expression of Epstein-Barr virus nuclear antigen (EBNA 1) when the structural portion of its gene, found within the 2.9-kilobase-pair BamHI/HindIII fragment called Ilf, is expressed from a simian virus 40 vector. A set of nested deletions at the BamHI end of the fragment was constructed by using BAL 31 digestion, the addition of linkers, and ligation into pSVOd. The mutants were tested for their ability to express antigen in COS-1 monkey cells by using indirect immunofluorescence and immunoblotting. Deletion endpoints were determined by DNA sequencing of the 5' ends of the mutants. The deletion mutants could be subclassified into four groups based on their ability to express EBNA polypeptide. Mutants that retain more than 106 base pairs upstream from the start of the open reading frame in Ilf exhibit antigen expression indistinguishable from that of wild type. Mutants that invade the structural gene by 1,115 or more bases destroy antigen expression. Mutants that alter the splice acceptor site or invade the open reading frame by a short distance make antigen at a markedly lower frequency. There are three mutants, whose deletions map at -78, -70, and -44 base pairs upstream of the open reading frame, that make reduced levels of EBNA. Since these three mutants differ in the extent to which EBNA expression is impaired, the data suggest that there are several critical regions upstream of the open reading frame that regulate EBNA expression in COS-1 cells. It is not known whether these regulatory sequences, which would be located in an intron in the intact genome, play any role in the expression of EBNA in infected lymphocytes. Images PMID:3009849

  20. Identification and Migration of Primordial Germ Cells in Atlantic Salmon, Salmo salar: Characterization of Vasa, Dead End, and Lymphocyte Antigen 75 Genes

    PubMed Central

    Nagasawa, Kazue; Fernandes, Jorge MO; Yoshizaki, Goro; Miwa, Misako; Babiak, Igor

    2013-01-01

    No information exists on the identification of primordial germ cells (PGCs) in the super-order Protacanthopterygii, which includes the Salmonidae family and Atlantic salmon (Salmo salar L.), one of the most commercially important aquatic animals worldwide. In order to identify salmon PGCs, we cloned the full-length cDNA of vasa, dead end (dnd), and lymphocyte antigen 75 (ly75/CD205) genes as germ cell marker candidates, and analyzed their expression patterns in both adult and embryonic stages of Atlantic salmon. Semi-quantitative RT-PCR results showed that salmon vasa and dnd were specifically expressed in testis and ovary, and vasa, dnd, and ly75 mRNA were maternally deposited in the egg. vasa mRNA was consistently detected throughout embryogenesis while dnd and ly75 mRNA were gradually degraded during cleavages. In situ analysis revealed the localization of vasa and dnd mRNA and Ly75 protein in PGCs of hatched larvae. Whole-mount in situ hybridization detected vasa mRNA during embryogenesis, showing a distribution pattern somewhat different to that of zebrafish; specifically, at mid-blastula stage, vasa-expressing cells were randomly distributed at the central part of blastodisc, and then they migrated to the presumptive region of embryonic shield. Therefore, the typical vasa localization pattern of four clusters during blastulation, as found in zebrafish, was not present in Atlantic salmon. In addition, salmon PGCs could be specifically labeled with a green fluorescence protein (GFP) using gfp-rt-vasa 3′-UTR RNA microinjection for further applications. These findings may assist in understanding PGC development not only in Atlantic salmon but also in other salmonids. PMID:23239145

  1. Antigenic sites in carcinoembryonic antigen.

    PubMed

    Hammarstrom, S; Shively, J E; Paxton, R J; Beatty, B G; Larsson, A; Ghosh, R; Bormer, O; Buchegger, F; Mach, J P; Burtin, P

    1989-09-01

    The epitope reactivities of 52 well-characterized monoclonal antibodies (Mabs) against carcinoembryonic antigen from 11 different research groups were studied using competitive solid-phase immunoassays. About 60% of all possible combinations of Mabs as inhibitors and as the primary binding antibody were investigated. The inhibition data were analyzed by a specially developed computer program "EPITOPES" which measures concordance and discordance in inhibition patterns between Mabs. The analysis showed that 43 of the 52 Mabs (83%) could be classified into one of five essentially noninteracting epitope groups (GOLD 1-5) containing between four and 15 Mabs each. The epitopes recognized by the Mabs belonging to groups 1 to 5 were peptide in nature. With one or two possible exceptions non-classifiable Mabs were either directed against carbohydrate epitopes (4 Mabs) or were inactive in the tests used. Within epitope groups GOLD 1, 4, and 5 two partially overlapping subgroups were distinguished. Mabs with a high degree of carcinoembryonic antigen specificity generally belonged to epitope groups GOLD 1 and 3. PMID:2474375

  2. Carriage of a Tumor Necrosis Factor Polymorphism Amplifies the Cytotoxic T-Lymphocyte Antigen 4 Attributed Risk of Primary Biliary Cirrhosis: Evidence for a Gene–Gene Interaction

    PubMed Central

    Juran, Brian D.; Atkinson, Elizabeth J.; Larson, Joseph J.; Schlicht, Erik M.; Liu, Xiangdong; Heathcote, E. Jenny; Hirschfield, Gideon M.; Siminovitch, Katherine A.; Lazaridis, Konstantinos N.

    2010-01-01

    Common genetic variants significantly influence complex diseases such as primary biliary cirrhosis (PBC). We recently reported an association between PBC and a single nucleotide polymorphism (rs231725) of the immunoreceptor gene cytotoxic T-lymphocyte antigen 4 (CTLA4). We hypothesized that PBC risk attributed to this polymorphism might be increased by propensity to an overly robust inflammatory response. Thus, we examined its potential interaction with the commonly studied −308AG promoter polymorphism (rs1800629) of the tumor necrosis factor (TNF) gene for which the variant TNF2A allele causes increased TNF production. The polymorphisms were genotyped in 866 PBC patients and 761 controls from independent US and Canadian registries; the effects of individual single nucleotide polymorphisms (SNPs) and their interaction on PBC risk was assessed by logistic regression. The reported association of PBC with the CTLA4 “A/A” genotype was replicated in the Canadian cohort and significant for PBC risk in the combined data (odds ratio [OR], 1.68; P = 0.0005). TNF2A allele frequency was elevated in PBC patients, but only reached borderline significance using the combined data (OR, 1.21; P = 0.042). Analysis showed that TNF2A carriage was significantly increased in CTLA4 “A/A” PBC patients compared with CTLA4 “A/A” controls (39.7% versus 16.5%, P = 0.0004); no apparent increase of TNF2A carriage was noted in CTLA4 “A/G” or “G/G” individuals. Finally, interaction under a logistic model was highly significant, as TNF2A carriage in combination with the CTLA4 “A/A” genotype was present in 6.5% of PBC patients, compared with 1.7% of controls (OR, 3.98; P < 0.0001). Conclusion TNF2A amplifies the CTLA4 rs231725 “A/A” genotype risk for PBC. Although the mechanisms remain unclear, the premise that deficiency in T-cell regulation resulting in an increased risk of PBC is amplified by overexpression of an important proinflammatory cytokine provides a basis

  3. The non-palindromic adaptor-PCR method for the identification of the T-cell receptor genes of an interferon-gamma-secreting T-cell hybridomaspecific for trans-sialidase, an immunodominant Trypanosoma cruzi antigen.

    PubMed

    Hiyane, M I; Boscardin, S B; Rodrigues, M M

    2006-03-01

    Cloning of the T-cell receptor genes is a critical step when generating T-cell receptor transgenic mice. Because T-cell receptor molecules are clonotypical, isolation of their genes requires reverse transcriptase-assisted PCR using primers specific for each different Valpha or Vbeta genes or by the screening of cDNA libraries generated from RNA obtained from each individual T-cell clone. Although feasible, these approaches are laborious and costly. The aim of the present study was to test the application of the non-palindromic adaptor-PCR method as an alternative to isolate the genes encoding the T-cell receptor of an antigen-specific T-cell hybridoma. For this purpose, we established hybridomas specific for trans-sialidase, an immunodominant Trypanosoma cruzi antigen. These T-cell hybridomas were characterized with regard to their ability to secrete interferon-gamma, IL-4, and IL-10 after stimulation with the antigen. A CD3+, CD4+, CD8- interferon-gamma-producing hybridoma was selected for the identification of the variable regions of the T-cell receptor by the non-palindromic adaptor-PCR method. Using this methodology, we were able to rapidly and efficiently determine the variable regions of both T-cell receptor chains. The results obtained by the non-palindromic adaptor-PCR method were confirmed by the isolation and sequencing of the complete cDNA genes and by the recognition with a specific antibody against the T-cell receptor variable beta chain. We conclude that the non-palindromic adaptor-PCR method can be a valuable tool for the identification of the T-cell receptor transcripts of T-cell hybridomas and may facilitate the generation of T-cell receptor transgenic mice. PMID:16501814

  4. The toxin-coregulated pilus (TCP) of Vibrio cholerae: molecular cloning of genes involved in pilus biosynthesis and evaluation of TCP as a protective antigen in the infant mouse model.

    PubMed

    Sharma, D P; Stroeher, U H; Thomas, C J; Manning, P A; Attridge, S R

    1989-12-01

    A serum containing antibodies to non-lipopolysaccharide (non-LPS) protective antigens of Vibrio cholerae has been used, after extensive absorption, to facilitate the cloning of genes involved in the synthesis of toxin-coregulated pili (TCP). A gene bank was constructed from V. cholerae Z17561 DNA using a mobilizable cosmid vector in Escherichia coli, and subsequently transferred by conjugation into V. cholerae O17. This strain does not produce TCP in vitro and lacks non-LPS protective antigens. Eight positive clones were isolated, and of these, four produced TCP as determined by electron microscopic and immunoblotting analyses. TCP-positive O17 clones were 70-fold more virulent than TCP-negative clones or O17 in the infant mouse cholera model. Only the former could remove protective antibodies from the clone-probing serum by absorption. As a corollary, serum containing antibodies to TCP protected mice from challenge with TCP-positive clones, but not with TCP-negative clones or O17. Our data indicate that TCP can function as both a virulence determinant and a protective antigen in the infant mouse model. PMID:2576091

  5. Distinct Transcript Isoforms of the Atypical Chemokine Receptor 1 (ACKR1) / Duffy Antigen Receptor for Chemokines (DARC) Gene Are Expressed in Lymphoblasts and Altered Isoform Levels Are Associated with Genetic Ancestry and the Duffy-Null Allele

    PubMed Central

    Davis, Melissa B.; Walens, Andrea; Hire, Rupali; Mumin, Kauthar; Brown, Andrea M.; Ford, DeJuana; Howerth, Elizabeth W.; Monteil, Michele

    2015-01-01

    The Atypical ChemoKine Receptor 1 (ACKR1) gene, better known as Duffy Antigen Receptor for Chemokines (DARC or Duffy), is responsible for the Duffy Blood Group and plays a major role in regulating the circulating homeostatic levels of pro-inflammatory chemokines. Previous studies have shown that one common variant, the Duffy Null (Fy-) allele that is specific to African Ancestry groups, completely removes expression of the gene on erythrocytes; however, these individuals retain endothelial expression. Additional alleles are associated with a myriad of clinical outcomes related to immune responses and inflammation. In addition to allele variants, there are two distinct transcript isoforms of DARC which are expressed from separate promoters, and very little is known about the distinct transcriptional regulation or the distinct functionality of these protein isoforms. Our objective was to determine if the African specific Fy- allele alters the expression pattern of DARC isoforms and therefore could potentially result in a unique signature of the gene products, commonly referred to as antigens. Our work is the first to establish that there is expression of DARC on lymphoblasts. Our data indicates that people of African ancestry have distinct relative levels of DARC isoforms expressed in these cells. We conclude that the expression of both isoforms in combination with alternate alleles yields multiple Duffy antigens in ancestry groups, depending upon the haplotypes across the gene. Importantly, we hypothesize that DARC isoform expression patterns will translate into ancestry-specific inflammatory responses that are correlated with the axis of pro-inflammatory chemokine levels and distinct isoform-specific interactions with these chemokines. Ultimately, this work will increase knowledge of biological mechanisms underlying disparate clinical outcomes of inflammatory-related diseases among ethnic and geographic ancestry groups. PMID:26473357

  6. Antigen Recognition By Variable Lymphocyte Receptors

    SciTech Connect

    Han, B.W.; Herrin, B.R.; Cooper, M.D.; Wilson, I.A.

    2009-05-18

    Variable lymphocyte receptors (VLRs) rather than antibodies play the primary role in recognition of antigens in the adaptive immune system of jawless vertebrates. Combinatorial assembly of leucine-rich repeat (LRR) gene segments achieves the required repertoire for antigen recognition. We have determined a crystal structure for a VLR-antigen complex, VLR RBC36 in complex with the H-antigen trisaccharide from human blood type O erythrocytes, at 1.67 angstrom resolution. RBC36 binds the H-trisaccharide on the concave surface of the LRR modules of the solenoid structure where three key hydrophilic residues, multiple van der Waals interactions, and the highly variable insert of the carboxyl-terminal LRR module determine antigen recognition and specificity. The concave surface assembled from the most highly variable regions of the LRRs, along with diversity in the sequence and length of the highly variable insert, can account for the recognition of diverse antigens by VLRs.

  7. Shared idiotopes among antibodies encoded by heavy-chain variable region (VH) gene members of the J558 VH family as basis for cross-reactive regulation of clones with different antigen specificity.

    PubMed Central

    Victor-Kobrin, C; Manser, T; Moran, T M; Imanishi-Kari, T; Gefter, M; Bona, C A

    1985-01-01

    A wide idiotype cross-reactivity was observed among six groups of monoclonal antibodies specific for arsonate and nitrophenyl haptens, hemagglutinin of PR8 and X31 influenza viruses, dextran, A48-idiotype, and a set of six monoclonal antibodies with unknown antigenic specificity. All of these antibodies are encoded by heavy-chain variable region (VH) genes belonging to the J558 VH family. This idiotypic cross-reactivity was determined by studying the binding of these antibodies to a panel of six monoclonal anti-idiotype antibodies, each one raised against a member of the six groups of monoclonal antibodies. The administration at birth of two such monoclonal anti-idiotype antibodies induced a long-lasting suppression not only of the corresponding idiotype but also of VH-related idiotypes with different antigenic specificities. These results suggest that the idiotypes encoded by VH genes that belong to the same VH gene family are interactive one with another. The possible physiological consequences of this immunochemical cross-reactivity are discussed. PMID:2415968

  8. Antigen S1, encoded by the MIC1 gene, is characterized as an epitope of human CD59, enabling measurement of mutagen-induced intragenic deletions in the AL cell system

    NASA Technical Reports Server (NTRS)

    Wilson, A. B.; Seilly, D.; Willers, C.; Vannais, D. B.; McGraw, M.; Waldren, C. A.; Hei, T. K.; Davies, A.; Chatterjee, A. (Principal Investigator)

    1999-01-01

    S1 cell membrane antigen is encoded by the MIC1 gene on human chromosome 11. This antigen has been widely used as a marker for studies in gene mapping or in analysis of mutagen-induced gene deletions/mutations, which utilized the human-hamster hybrid cell-line, AL-J1, carrying human chromosome 11. Evidence is presented here which identifies S1 as an epitope of CD59, a cell membrane complement inhibiting protein. E7.1 monoclonal antibody, specific for the S1 determinant, was found to react strongly with membrane CD59 in Western blotting, and to bind to purified, urinary form of CD59 in ELISAs. Cell membrane expression of S1 on various cell lines always correlated with that of CD59 when examined by immunofluorescent staining. In addition, E7.1 antibody inhibited the complement regulatory function of CD59. Identification of S1 protein as CD59 has increased the scope of the AL cell system by enabling analysis of intragenic mutations, and multiplex PCR analysis of mutated cells is described, showing variable loss of CD59 exons.

  9. Genetic Mapping of the Antigenic Determinants of Two Polysaccharide K Antigens, K10 and K54, in Escherichia coli

    PubMed Central

    Ørskov, Ida; Nyman, Kate

    1974-01-01

    The genes controlling synthesis of the Escherichia coli acidic polysaccharide capsular antigens K10 and K54 were transferred by conjugation to E. coli strains of other serotypes. The genes concerned with these K antigen determinants showed genetic linkage with the serA locus. We propose to name the K antigen-controlling gene kpsA. The genetic determinants of the two K antigens could also be transferred to enteropathogenic serotypes, even though such strains have never been found in nature with special acidic polysaccharide K antigens. A noncapsulated derivative, K−, of the K10 strain can transfer the genetic determinant of the K antigen, demonstrating the probable existence of another chromosomal locus involved in the production of such acidic polysaccharide K antigens. PMID:4138850

  10. Preparation and diagnostic utility of a hemagglutination inhibition test antigen derived from the baculovirus-expressed hemagglutinin-neuraminidase protein gene of Newcastle disease virus.

    PubMed

    Choi, Kang-Seuk; Kye, Soo-Jeong; Jeon, Woo-Jin; Park, Mi-Ja; Kim, Saeromi; Seul, Hee-Jung; Kwon, Jun-Hun

    2013-01-01

    A recombinant hemagglutinin-neuraminidase (rHN) protein from Newcastle disease virus (NDV) with hemagglutination (HA) activity was expressed in Spodoptera frugiperda cells using a baculovirus expression system. The rHN protein extracted from infected cells was used as an antigen in a hemagglutination inhibition (HI) test for the detection and titration of NDV-specific antibodies present in chicken sera. The rHN antigen produced high HA titers of 2(13) per 25 μL, which were similar to those of the NDV antigen produced using chicken eggs, and it remained stable without significant loss of the HA activity for at least 12 weeks at 4°C. The rHN-based HI assay specifically detected NDV antibodies, but not the sera of other avian pathogens, with a specificity and sensitivity of 100% and 98.0%, respectively, in known positive and negative chicken sera (n = 430). Compared with an NDV-based HI assay, the rHN-based HI assay had a relative sensitivity and specificity of 96.1% and 95.5%, respectively, when applied to field chicken sera. The HI titers of the rHN-based HI assay were highly correlated with those in an NDV-based HI assay (r = 0.927). Overall, these results indicate that rHN protein provides a useful alternative to NDV antigen in HI assays. PMID:23820164

  11. The 65-kilodalton antigen of Mycobacterium tuberculosis.

    PubMed Central

    Shinnick, T M

    1987-01-01

    The immune response of the host to the antigens of Mycobacterium tuberculosis plays the key role in determining immunity from infection with as well as the pathogenicity of this organism. A 65-kilodalton (kDa) protein has been identified as one of the medically important antigens of M. tuberculosis. The gene encoding this antigen was isolated from a lambda gt11-M. tuberculosis recombinant DNA library using monoclonal antibodies directed against the 65-kDa antigen as the specific probes. The nucleotide sequence of this gene was determined, and a 540-amino-acid sequence was deduced. This sequence was shown to correspond to that of the 65-kDa antigen by constructing a plasmid in which this open reading frame was fused to the lacZ gene. The resulting fusion protein reacted specifically with the anti-65-kDa protein antibodies. A second long open reading frame was found downstream of the 65-kDa antigen gene which could encode a protein of 517 amino acids. This putative protein contained 29 tandemly arranged partial or complete matches to a pentapeptide sequence. Images PMID:3029018

  12. Antigenic determinants and functional domains in core antigen and e antigen from hepatitis B virus

    SciTech Connect

    Salfeld, J.; Pfaff, E.; Noah, M.; Schaller, H.

    1989-02-01

    The precore/core gene of hepatitis B virus directs the synthesis of two polypeptides, the 21-kilodalton subunit (p21c) forming the viral nucleocapsid (serologically defined as core antigen (HBcAg)) and a secreted processed protein (p17e, serologically defined as HBe antigen (HBeAg)). Although most of their primary amino acid sequences are identical, HBcAg and HBeAg display different antigenic properties that are widely used in hepatitis B virus diagnosis. To locate and to characterize the corresponding determinants, segments of the core gene were expressed in Escherichia coli and probed with a panel of polyclonal or monoclonal antibodies in radioimmunoassays or enzyme-linked immunosorbent assays, Western blots, and competition assays. Three distinct major determinants were characterized. It is postulated that HBcAg and HBeAg share common basic three-dimensional structure exposing the common linear determinant HBe1 but that they differ in the presentation of two conformational determinants that are either introduced (HBc) or masked (HBe2) in the assembled core. The simultaneous presentation of HBe1 and HBc, two distinctly different antigenic determinants with overlapping amino acid sequences, is interpreted to indicate the presence of slightly differently folded, stable conformational states of p21c in the hepatitis virus nucleocapsid.

  13. Sequence Variations in the Flagellar Antigen Genes fliCH25 and fliCH28 of Escherichia coli and Their Use in Identification and Characterization of Enterohemorrhagic E. coli (EHEC) O145:H25 and O145:H28

    PubMed Central

    Beutin, Lothar; Delannoy, Sabine; Fach, Patrick

    2015-01-01

    Enterohemorrhagic E. coli (EHEC) serogroup O145 is regarded as one of the major EHEC serogroups involved in severe infections in humans. EHEC O145 encompasses motile and non-motile strains of serotypes O145:H25 and O145:H28. Sequencing the fliC-genes associated with the flagellar antigens H25 and H28 revealed the genetic diversity of the fliCH25 and fliCH28 gene sequences in E. coli. Based on allele discrimination of these fliC-genes real-time PCR tests were designed for identification of EHEC O145:H25 and O145:H28. The fliCH25 genes present in O145:H25 were found to be very similar to those present in E. coli serogroups O2, O100, O165, O172 and O177 pointing to their common evolution but were different from fliCH25 genes of a multiple number of other E. coli serotypes. In a similar way, EHEC O145:H28 harbor a characteristic fliCH28 allele which, apart from EHEC O145:H28, was only found in enteropathogenic (EPEC) O28:H28 strains that shared some common traits with EHEC O145:H28. The real time PCR-assays targeting these fliCH25[O145] and fliCH28[O145] alleles allow better characterization of EHEC O145:H25 and EHEC O145:H28. Evaluation of these PCR assays in spiked ready-to eat salad samples resulted in specific detection of both types of EHEC O145 strains even when low spiking levels of 1–10 cfu/g were used. Furthermore these PCR assays allowed identification of non-motile E. coli strains which are serologically not typable for their H-antigens. The combined use of O-antigen genotyping (O145wzy) and detection of the respective fliCH25[O145] and fliCH28[O145] allele types contributes to improve identification and molecular serotyping of E. coli O145 isolates. PMID:26000885

  14. Association of Nucleotide Polymorphisms within the O-Antigen Gene Cluster of Escherichia coli O26, O45, O103, O111, O121, and O145 with Serogroups and Genetic Subtypes

    PubMed Central

    Norman, Keri N.; Strockbine, Nancy A.

    2012-01-01

    Shiga toxin-producing Escherichia coli (STEC) strains are important food-borne pathogens capable of causing hemolytic-uremic syndrome. STEC O157:H7 strains cause the majority of severe disease in the United States; however, there is a growing concern for the amount and severity of illness attributable to non-O157 STEC. Recently, the Food Safety and Inspection Service (FSIS) published the intent to regulate the presence of STEC belonging to serogroups O26, O45, O103, O111, O121, and O145 in nonintact beef products. To ensure the effective control of these bacteria, sensitive and specific tests for their detection will be needed. In this study, we identified single nucleotide polymorphisms (SNPs) in the O-antigen gene cluster that could be used to detect STEC strains of the above-described serogroups. Using comparative DNA sequence analysis, we identified 22 potentially informative SNPs among 164 STEC and non-STEC strains of the above-described serogroups and designed matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF) assays to test the STEC allele frequencies in an independent panel of bacterial strains. We found at least one SNP that was specific to each serogroup and also differentiated between STEC and non-STEC strains. Differences in the DNA sequence of the O-antigen gene cluster corresponded well with differences in the virulence gene profiles and provided evidence of different lineages for STEC and non-STEC strains. The SNPs discovered in this study can be used to develop tests that will not only accurately identify O26, O45, O103, O111, O121, and O145 strains but also predict whether strains detected in the above-described serogroups contain Shiga toxin-encoding genes. PMID:22798363

  15. Evaluation of Selected Borrelia burgdorferi lp54 Plasmid-Encoded Gene Products Expressed during Mammalian Infection as Antigens To Improve Serodiagnostic Testing for Early Lyme Disease

    PubMed Central

    Weiner, Zachary P.; Crew, Rebecca M.; Brandt, Kevin S.; Ullmann, Amy J.; Schriefer, Martin E.; Molins, Claudia R.

    2015-01-01

    Laboratory testing for the diagnosis of Lyme disease is performed primarily by serologic assays and is accurate for detection beyond the acute stage of the infection. Serodiagnostic assays to detect the early stages of infection, however, are limited in their sensitivity, and improvement is warranted. We analyzed a series of Borrelia burgdorferi proteins known to be induced within feeding ticks and/or during mammalian infection for their utility as serodiagnostic markers against a comprehensive panel of Lyme disease patient serum samples. The antigens were assayed for IgM and IgG reactivity in line immunoblots and separately by enzyme-linked immunosorbent assay (ELISA), with a focus on reactivity against early Lyme disease with erythema migrans (EM), early disseminated Lyme neuroborreliosis, and early Lyme carditis patient serum samples. By IgM immunoblotting, we found that recombinant proteins BBA65, BBA70, and BBA73 reacted with early Lyme EM samples at levels comparable to those of the OspC antigen used in the current IgM blotting criteria. Additionally, these proteins reacted with serum samples from patients with early neuroborreliosis and early carditis, suggesting value in detecting early stages of this disease progression. We also found serological reactivity against recombinant proteins BBA69 and BBA73 with early-Lyme-disease samples using IgG immunoblotting and ELISA. Significantly, some samples that had been scored negative by the Centers for Disease Control and Prevention-recommended 2-tiered testing algorithm demonstrated positive reactivity to one or more of the antigens by IgM/IgG immunoblot and ELISA. These results suggest that incorporating additional in vivo-expressed antigens into the current IgM/IgG immunoblotting tier in a recombinant protein platform assay may improve the performance of early-Lyme-disease serologic testing. PMID:26376927

  16. Rotavirus antigen test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003349.htm Rotavirus antigen test To use the sharing features on this page, please enable JavaScript. The rotavirus antigen test detects rotavirus in the feces. This ...

  17. Genetic Diversity of the fliC Genes Encoding the Flagellar Antigen H19 of Escherichia coli and Application to the Specific Identification of Enterohemorrhagic E. coli O121:H19

    PubMed Central

    Beutin, Lothar; Delannoy, Sabine

    2015-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O121:H19 belong to a specific clonal type distinct from other classical EHEC and major enteropathogenic E. coli groups and is regarded as one of the major EHEC serogroups involved in severe infections in humans. Sequencing of the fliC genes associated with the flagellar antigen H19 (fliCH19) revealed the genetic diversity of the fliCH19 gene sequences in E. coli. A cluster analysis of 12 fliCH19 sequences, 4 from O121 and 8 from non-O121 E. coli strains, revealed five different genotypes. All O121:H19 strains fell into one cluster, whereas a second cluster was formed by five non-O121:H19 strains. Cluster 1 and cluster 2 strains differ by 27 single nucleotide exchanges in their fliCH19 genes (98.5% homology). Based on allele discrimination of the fliCH19 genes, a real-time PCR test was designed for specific identification of EHEC O121:H19. The O121 fliCH19 PCR tested negative in 73 E. coli H19 strains that belonged to serogroups other than O121, including 28 different O groups, O-nontypeable H19, and O-rough:H19 strains. The O121 fliCH19 PCR reacted with all 16 tested O121:H19 strains and 1 O-rough:H19 strain which was positive for the O121 wzx gene. A cross-reaction was observed only with E. coli H32 strains which share sequence similarities in the target region of the O121 fliCH19 PCR. The combined use of O-antigen genotyping (O121 wzx) and the detection of O121 fliCH19 allele type contributes to improving the identification and molecular serotyping of EHEC O121:H19 motile and nonmotile strains and variants of these strains lacking stx genes. PMID:25862232

  18. The immunohistochemical detection of mismatch repair gene proteins (MLH1, MSH2, MSH6, and PMS2): practical aspects in antigen retrieval and biotin blocking protocols.

    PubMed

    Manavis, Jim; Gilham, Peter; Davies, Ruth; Ruszkiewicz, Andrew

    2003-03-01

    The immunohistochemical detection of the mismatch repair (MMR) proteins is used as a screening test with microsatellite instability for the detection of hereditary nonpolyposis colon cancer (HNPCC). The authors describe a simple and cost-effective method using a pressure cooker and microwave oven for antigen retrieval and a modified method for applying a commercial biotin blocking kit. Colorectal tumors of 20 patients of the HNPCC spectrum were included in this study. Eighty paraffin sections were cut and submitted for immunohistochemical analysis using a routine protocol and a pressure cooker protocol. Parallel sections for biotin blocking were also run, including the modified biotin block for each protocol. The sections were incubated with the following antibodies: MLH1, MSH2, MSH6, and PMS2. All cases examined exhibited a normal expression of the MMR proteins in the nucleus and adjacent nonneoplastic tissue elements and consequently defined as having a normal expression of these proteins. Cases with tumor that exhibited a loss of the nuclear staining with the MMR proteins with a concurrent staining of the adjacent nonneoplastic cells were classified as abnormal MMR expression. The series of 20 cases using pressure cooker antigen retrieval produced superior results to the routine immunohistochemical protocol used previously in our laboratory. The modified biotin block also gave consistent results. The reproducibility and consistency of this procedure has resulted it in being used routinely for suspected HNPCC cases, both current and archival. PMID:12610360

  19. An efficient antigene activity and antiproliferative effect by targeting the Bcl-2 or survivin gene with triplex forming oligonucleotides containing a W-shaped nucleoside analogue (WNA-βT).

    PubMed

    Taniguchi, Yosuke; Sasaki, Shigeki

    2012-10-01

    Triplex forming oligonucleotides (TFOs) are some of the most promising tools in the antigene strategy for the development of gene targeting therapeutics. However, the stable triplex formation is restricted to the homopurine sequences consisting of purine nucleosides, dG and dA. Therefore, the T or dC nucleoside in the homopurine strand inhibits the stable triplex formation. We have developed W-shaped nucleoside analogues (WNAs) for the formation of the unnatural type triplex DNA, with sequences containing the interrupting site in an antiparallel triplex formation. In the present study, we tested the antigene effect of TFOs having WNA-βT, which increased the stability of the triplex formation with a target sequence including the TA interrupting site. We designed the GU TFO (WNA) and GU TFO (natural) for targeting sequences of the Bcl-2 or survivin oncogene. The gel shift assay showed that the TFO (WNA) formed more stable triplexes than the natural TFO. Remarkably, the Bcl-2- or survivin-targeted TFO (WNA) inhibited the cell proliferation and induced a caspase-dependent apoptosis. It was confirmed that the survivin-targeted TFO (WNA) more effectively decreased the number of survivin products in the A549 cell than the natural TFOs. PMID:22987068

  20. Two amino acid substitutions in apolipoprotein B are in complete allelic association with the antigen group (x/y) polymorphism: Evidence for little recombination in the 3 prime end of the human gene

    SciTech Connect

    Dunning, A.M.; Renges, H.H.; Xu, Chunfang; Peacock, R.; Humphries, S.E.; Talmud, P.; Laxer, G. ); Brasseur, R. ); Tikkanen, M.J. ); Buetler, R. ); Saha, N. ); Hamsten, A. ); Rosseneu, M. )

    1992-01-01

    The authors report the identification of an A-to-G base change, in exon 29 of the apolipoprotein B (apo B) gene, that results in the substitution of serine for asparagine at residue 4,311 of mature apo B100. In a recent publication, Huang et al. have reported a C-to-T base change in exon 26 that causes the substitution of leucine for proline at residue 2712 of apo B. The authors have found complete linkage disequilibrium between the alleles at both these sites and an immunochemical polymorphism of LDL designated antigen group (x/y) (Ag(x/y)) in a sample of 118 Finnish individuals. This implies that either one of these substitutions - or both of them combined - could be the molecular basis of the Ag(x/y) antigenic determinants, with the allele encoding serine{sub 4311} plus leucine{sub 2,712} representing the Ag(x) epitope, and that encoding asparagine{sub 4,311} plus proline{sub 2,712} the Ag(y) epitope. In a sample of 90 healthy Swedish individuals the Leu{sub 2,712}/Ser{sub 4,311} allele is associated both with reduced serum levels of LDL cholesterol and apo B and with raised levels of HDL. They have also genotyped 523 individuals from European, Asian, Chinese, and Afro-Caribbean populations and have found complete association between the sites encoding residues 2,712 and 4,311 in all of these samples, although there are large allele frequency differences between these populations. Taken together, these data suggest that, since the divergence of the major ethnic groups, there has been little or no recombination in the 3' end of the human apo B gene.

  1. Meningococcal vaccine antigen diversity in global databases

    PubMed Central

    Brehony, C; Hill, DM; Lucidarme, J; Borrow, R; Maiden, MC

    2016-01-01

    The lack of an anti-capsular vaccine against serogroup B meningococcal disease has necessitated the exploration of alternative vaccine candidates, mostly proteins exhibiting varying degrees of antigenic variation. Analysis of variants of antigen-encoding genes is facilitated by publicly accessible online sequence repositories, such as the Neisseria PubMLST database and the associated Meningitis Research Foundation Meningococcus Genome Library (MRF-MGL). We investigated six proposed meningococcal vaccine formulations by deducing the prevalence of their components in the isolates represented in these repositories. Despite high diversity, a limited number of antigenic variants of each of the vaccine antigens were prevalent, with strong associations of particular variant combinations with given serogroups and genotypes. In the MRF-MGL and globally, the highest levels of identical sequences were observed with multicomponent/multivariant vaccines. Our analyses further demonstrated that certain combinations of antigen variants were prevalent over periods of decades in widely differing locations, indicating that vaccine formulations containing a judicious choice of antigen variants have potential for long-term protection across geographic regions. The data further indicated that formulations with multiple variants would be especially relevant at times of low disease incidence, as relative diversity was higher. Continued surveillance is required to monitor the changing prevalence of these vaccine antigens. PMID:26676305

  2. Inactivation of Genes for Antigenic Variation in the Relapsing Fever Spirochete Borrelia hermsii Reduces Infectivity in Mice and Transmission by Ticks

    PubMed Central

    Raffel, Sandra J.; Battisti, James M.; Fischer, Robert J.; Schwan, Tom G.

    2014-01-01

    Borrelia hermsii, a causative agent of relapsing fever of humans in western North America, is maintained in enzootic cycles that include small mammals and the tick vector Ornithodoros hermsi. In mammals, the spirochetes repeatedly evade the host’s acquired immune response by undergoing antigenic variation of the variable major proteins (Vmps) produced on their outer surface. This mechanism prolongs spirochete circulation in blood, which increases the potential for acquisition by fast-feeding ticks and therefore perpetuation of the spirochete in nature. Antigenic variation also underlies the relapsing disease observed when humans are infected. However, most spirochetes switch off the bloodstream Vmp and produce a different outer surface protein, the variable tick protein (Vtp), during persistent infection in the tick salivary glands. Thus the production of Vmps in mammalian blood versus Vtp in ticks is a dominant feature of the spirochete’s alternating life cycle. We constructed two mutants, one which was unable to produce a Vmp and the other was unable to produce Vtp. The mutant lacking a Vmp constitutively produced Vtp, was attenuated in mice, produced lower cell densities in blood, and was unable to relapse in animals after its initial spirochetemia. This mutant also colonized ticks and was infectious by tick-bite, but remained attenuated compared to wild-type and reconstituted spirochetes. The mutant lacking Vtp also colonized ticks but produced neither Vtp nor a Vmp in tick salivary glands, which rendered the spirochete noninfectious by tick bite. Thus the ability of B. hermsii to produce Vmps prolonged its survival in blood, while the synthesis of Vtp was essential for mammalian infection by the bite of its tick vector. PMID:24699793

  3. Inactivation of genes for antigenic variation in the relapsing fever spirochete Borrelia hermsii reduces infectivity in mice and transmission by ticks.

    PubMed

    Raffel, Sandra J; Battisti, James M; Fischer, Robert J; Schwan, Tom G

    2014-04-01

    Borrelia hermsii, a causative agent of relapsing fever of humans in western North America, is maintained in enzootic cycles that include small mammals and the tick vector Ornithodoros hermsi. In mammals, the spirochetes repeatedly evade the host's acquired immune response by undergoing antigenic variation of the variable major proteins (Vmps) produced on their outer surface. This mechanism prolongs spirochete circulation in blood, which increases the potential for acquisition by fast-feeding ticks and therefore perpetuation of the spirochete in nature. Antigenic variation also underlies the relapsing disease observed when humans are infected. However, most spirochetes switch off the bloodstream Vmp and produce a different outer surface protein, the variable tick protein (Vtp), during persistent infection in the tick salivary glands. Thus the production of Vmps in mammalian blood versus Vtp in ticks is a dominant feature of the spirochete's alternating life cycle. We constructed two mutants, one which was unable to produce a Vmp and the other was unable to produce Vtp. The mutant lacking a Vmp constitutively produced Vtp, was attenuated in mice, produced lower cell densities in blood, and was unable to relapse in animals after its initial spirochetemia. This mutant also colonized ticks and was infectious by tick-bite, but remained attenuated compared to wild-type and reconstituted spirochetes. The mutant lacking Vtp also colonized ticks but produced neither Vtp nor a Vmp in tick salivary glands, which rendered the spirochete noninfectious by tick bite. Thus the ability of B. hermsii to produce Vmps prolonged its survival in blood, while the synthesis of Vtp was essential for mammalian infection by the bite of its tick vector. PMID:24699793

  4. Mosaic VSGs and the Scale of Trypanosoma brucei Antigenic Variation

    PubMed Central

    Hall, James P. J.; Wang, Huanhuan; Barry, J. David

    2013-01-01

    A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG) coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct ‘mosaic’ VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection. PMID:23853603

  5. Antigenic variation with a twist--the Borrelia story.

    PubMed

    Norris, Steven J

    2006-06-01

    A common mechanism of immune evasion in pathogenic bacteria and protozoa is antigenic variation, in which genetic or epigenetic changes result in rapid, sequential shifts in a surface-exposed antigen. In this issue of Molecular Microbiology, Dai et al. provide the most complete description to date of the vlp/vsp antigenic variation system of the relapsing fever spirochaete, Borrelia hermsii. This elaborate, plasmid-encoded system involves an expression site that can acquire either variable large protein (vlp) or variable small protein (vsp) surface lipoprotein genes from 59 different archival copies. The archival vlp and vsp genes are arranged in clusters on at least five different plasmids. Gene conversion occurs through recombination events at upstream homology sequences (UHS) found in each gene copy, and at downstream homology sequences (DHS) found periodically among the vlp/vsp archival genes. Previous studies have shown that antigenic variation in relapsing fever Borrelia not only permits the evasion of host antibody responses, but can also result in changes in neurotropism and other pathogenic properties. The vlsE antigenic variation locus of Lyme disease spirochaetes, although similar in sequence to the relapsing fever vlp genes, has evolved a completely different antigenic variation mechanism involving segmental recombination from a contiguous array of vls silent cassettes. These two systems thus appear to represent divergence from a common precursor followed by functional convergence to create two distinct antigenic variation processes. PMID:16796669

  6. Antigenic variation in African trypanosomes

    PubMed Central

    Horn, David

    2014-01-01

    Studies on Variant Surface Glycoproteins (VSGs) and antigenic variation in the African trypanosome, Trypanosoma brucei, have yielded a remarkable range of novel and important insights. The features first identified in T. brucei extend from unique to conserved-among-trypanosomatids to conserved-among-eukaryotes. Consequently, much of what we now know about trypanosomatid biology and much of the technology available has its origin in studies related to VSGs. T. brucei is now probably the most advanced early branched eukaryote in terms of experimental tractability and can be approached as a pathogen, as a model for studies on fundamental processes, as a model for studies on eukaryotic evolution or often all of the above. In terms of antigenic variation itself, substantial progress has been made in understanding the expression and switching of the VSG coat, while outstanding questions continue to stimulate innovative new approaches. There are large numbers of VSG genes in the genome but only one is expressed at a time, always immediately adjacent to a telomere. DNA repair processes allow a new VSG to be copied into the single transcribed locus. A coordinated transcriptional switch can also allow a new VSG gene to be activated without any detectable change in the DNA sequence, thereby maintaining singular expression, also known as allelic exclusion. I review the story behind VSGs; the genes, their expression and switching, their central role in T. brucei virulence, the discoveries that emerged along the way and the persistent questions relating to allelic exclusion in particular. PMID:24859277

  7. Consensus HIV-1 FSU-A Integrase Gene Variants Electroporated into Mice Induce Polyfunctional Antigen-Specific CD4+ and CD8+ T Cells

    PubMed Central

    Krotova, Olga; Starodubova, Elizaveta; Petkov, Stefan; Kostic, Linda; Agapkina, Julia; Hallengärd, David; Viklund, Alecia; Latyshev, Oleg; Gelius, Eva; Dillenbeck, Tomas; Karpov, Vadim; Gottikh, Marina; Belyakov, Igor M.; Lukashov, Vladimir; Isaguliants, Maria G.

    2013-01-01

    Our objective is to create gene immunogens targeted against drug-resistant HIV-1, focusing on HIV-1 enzymes as critical components in viral replication and drug resistance. Consensus-based gene vaccines are specifically fit for variable pathogens such as HIV-1 and have many advantages over viral genes and their expression-optimized variants. With this in mind, we designed the consensus integrase (IN) of the HIV-1 clade A strain predominant in the territory of the former Soviet Union and its inactivated derivative with and without mutations conferring resistance to elvitegravir. Humanized IN gene was synthesized; and inactivated derivatives (with 64D in the active site mutated to V) with and without elvitegravir-resistance mutations were generated by site-mutagenesis. Activity tests of IN variants expressed in E coli showed the consensus IN to be active, while both D64V-variants were devoid of specific activities. IN genes cloned in the DNA-immunization vector pVax1 (pVaxIN plasmids) were highly expressed in human and murine cell lines (>0.7 ng/cell). Injection of BALB/c mice with pVaxIN plasmids followed by electroporation generated potent IFN-γ and IL-2 responses registered in PBMC by day 15 and in splenocytes by day 23 after immunization. Multiparametric FACS demonstrated that CD8+ and CD4+ T cells of gene-immunized mice stimulated with IN-derived peptides secreted IFN-γ, IL-2, and TNF-α. The multi-cytokine responses of CD8+ and CD4+ T-cells correlated with the loss of in vivo activity of the luciferase reporter gene co-delivered with pVaxIN plasmids. This indicated the capacity of IN-specific CD4+ and CD8+ T-cells to clear IN/reporter co-expressing cells from the injection sites. Thus, the synthetic HIV-1 clade A integrase genes acted as potent immunogens generating polyfunctional Th1-type CD4+ and CD8+ T cells. Generation of such response is highly desirable for an effective HIV-1 vaccine as it offers a possibility to attack virus-infected cells via both MHC

  8. HLA-DQA1 and HLA-DQB1 genes in Tsachilas Indians from Ecuador: new insights in population analysis by Human Leukocyte Antigens.

    PubMed

    Iorio, A; De Angelis, F; Garzoli, A; Battistini, A; De Stefano, G F

    2014-06-01

    Human Leucocyte Antigen (HLA) loci are widely known for their role in the generation of immune responses and are often considered to be effective in reconstructing human relationships. This is due to the high degree of polymorphism and the rarity of recombination observed at HLA loci. In this study, we have made an attempt to support the potential of HLA class II loci by analysing DQA1 and DQB1 in 52 Ecuadorians with ties to the Tsachilas community. Little is known about this populations either ethnologically or historically: they are considered retaining much of the ancient Chibchan culture in spite of the lack of significant genetic characterization. A total of 21 alleles were observed, with very low heterozygosity. The obtained data were then assessed for relationship reconstruction. The compiled database of 63 populations was segregated and resolved in clusters corresponding to the ethnogeographic distribution of the populations. This analysis of Central and Southern Amerindians allowed us to support a historical hypothesis related to the origin and migration of Ecuadorian people. Indeed, the relationships with neighbour human groups, especially Cayapas and Colombians, could shed light on the genetic similarity within ancient Chibchan culture that was dispersed by tribes coming up the Barbacoas. This indicates that if an appropriate analysis was to be carried out on a set of populations representative of different geographic locations, and that analysis was properly interpreted, then there would be a high possibility that HLA class II loci could infer accurate assessments, as revealed by uniparental markers. PMID:24775353

  9. Two amino acid substitutions in apolipoprotein B are in complete allelic association with the antigen group (x/y) polymorphism: Evidence for little recombination in the 3' end of the human gene

    PubMed Central

    Dunning, Alison M.; Renges, Helmut-H.; Xu, Chun-Fang; Peacock, Rachel; Brasseur, Robert; Laxer, Gerald; Tikkanen, Matti J.; Bütler, Réné; Saha, N.; Hamsten, Anders; Rosseneu, Maryvonne; Talmud, Philippa; Humphries, Steve E.

    1992-01-01

    We report the identification of an A-to-G base change, in exon 29 of the apolipoprotein B (apo B) gene, that results in the substitution of serine for asparagine at residue 4311 of mature apo B100. In a recent publication, Huang et al. have reported a C-to-T base change in exon 26 that causes the substitution of leucine for proline at residue 2712 of apo B. We have found complete linkage disequilibrium between the alleles at both these sites and an immunochemical polymorphism of LDL designated antigen group (x/y) (Ag(x/y)) in a sample of 118 Finnish individuals. This implies that either one of these substitutions–or both of them combined–could be the molecular basis of the Ag(x/y) antigenic determinants, with the allele encoding serine4311 plus leucine2712 representing the Ag(x) epitope, and that encoding asparagine4311 plus proline2712 the Ag(y) epitope. In a sample of 90 healthy Swedish individuals the Leu2712/Ser4311 allele is associated both with reduced serum levels of LDL-cholesterol and apo B and with raised levels of HDL. However, these differences are of smaller effect than those associated with the XbaI RFLP of the apo B gene in this sample. We have also genotyped 523 individuals from European, Asian, Chinese, and Afro-Caribbean populations and have found complete association between the sites encoding residues 2712 and 4311 in all of these samples, although there are large allele frequency differences between these populations. In addition, there is strong linkage disequilibrium with allelic association between the alleles of these sites and those of the XbaI RFLP in all the populations examined. Taken together, these data suggest that, since the divergence of the major ethnic groups, there has been little or no recombination in the 3' end of the human apo B gene. ImagesFigure 1Figure 2Figure 3 PMID:1370364

  10. Association of Polymorphisms in the Prostate-Specific Antigen (PSA) Gene Promoter with Serum PSA Level and PSA Changes after Dutasteride Treatment in Korean Men with Benign Prostatic Hypertrophy

    PubMed Central

    Park, Sung Woon; Kim, Chul Sung

    2010-01-01

    Purpose Studies of genetic variation in the prostate-specific antigen (PSA) gene have improved the diagnostic accuracy of PSA for diagnosing prostate diseases in Caucasians. However, the reference ranges and pharmacokinetics of PSA differ significantly according to race. Therefore, we evaluated the association between genetic variations in the PSA promoter area and benign prostatic hyperplasia (BPH) phenotypes in Korean BPH patients. Materials and Methods One hundred twenty-one men were enrolled. The initial serum PSA level, prostate size, and PSA changes at 3 months after treatment with dutasteride were determined. We amplified the promoter region of the PSA gene (nucleotide positions -158 to -356 and -5217 to -5429) and sequenced the products. Results Three relatively well characterized single-nucleotide polymorphisms (SNPs; rs3760722, rs266867, and rs266868), six uncharacterized SNPs (rs17554958, rs266882, rs4802754, rs2739448, rs2569733, and rs17526278), and one novel SNP (nucleotide position -5402) were found. There were no statistically significant correlations between any of the SNPs of the PSA promoter area and age-adjusted prostate sizes, initial PSA levels, or PSA variations after 3 months of dutasteride treatment. Conclusions SNPs in the PSA promoter area were not associated with BPH phenotypes. We could not predict serum PSA changes after dutasteride treatment on the basis of PSA promoter genotype in Korean patients with BPH. PMID:21221201

  11. Transcutaneous antigen delivery system

    PubMed Central

    Lee, Mi-Young; Shin, Meong-Cheol; Yang, Victor C.

    2013-01-01

    Transcutaneous immunization refers to the topical application of antigens onto the epidermis. Transcutaneous immunization targeting the Langerhans cells of the skin has received much attention due to its safe, needle-free, and noninvasive antigen delivery. The skin has important immunological functions with unique roles for antigen-presenting cells such as epidermal Langerhans cells and dermal dendritic cells. In recent years, novel vaccine delivery strategies have continually been developed; however, transcutaneous immunization has not yet been fully exploited due to the penetration barrier represented by the stratum corneum, which inhibits the transport of antigens and adjuvants. Herein we review recent achievements in transcutaneous immunization, focusing on the various strategies for the enhancement of antigen delivery and vaccination efficacy. [BMB Reports 2013; 46(1): 17-24] PMID:23351379

  12. Expression and sequences of T cell antigen receptor beta-chain genes in the thymus at an early stage after sublethal irradiation

    SciTech Connect

    Yuuki, H.; Yoshikai, Y.; Kishihara, K.; Matsuzaki, G.; Ayukawa, K.; Nomoto, K.

    1989-05-15

    The sequential appearance of the thymocyte subpopulations and TCR gene messages occurred in the thymus of AKR mice (H-2k, Mlsa) from 7 to 14 days after sublethal irradiation. The thymocytes on day 7 after irradiation were composed of a large number of CD4+CD8+ blast-like cells and a relatively high proportion of CD4-CD8- cells (15 to 25%) but few CD3highCD4+CD8-/CD4-CD8+ cells. Approximately 22% of the CD4-CD8- cells were CD3high and -27% of the CD3highCD4-CD8- cells (-6% of whole CD4-CD8- cells) were F23.1+. The thymocytes on day 7 expressed a large amount of gamma- and delta-chain gene transcripts but reduced levels of alpha- and beta-chain gene transcripts. The V gene repertoire of 18 functional beta-chain cDNA derived from the thymocytes on day 7 was compared with those of 20 functional beta-chain cDNA derived from the thymocytes on day 14 which were composed of a large number of CD3lowCD4+CD8+ small-sized cells and a small number of CD3highCD4+CD8- cells. It is noteworthy that the distribution of V beta genes expressed in the thymocytes on day 7 was much the same as that in the thymocytes on day 14 but significantly different from that in normal BALB/c thymocytes as previously described. Interestingly, neither V beta 8.1 nor V beta 6 genes, which are important for recognition of the product of the Mlsa locus, was detected in these two cDNA libraries. These results suggest that clonal selection of TCR V beta repertoire, irrespective of positive or negative selection, appears to occur at the early stage of T cell differentiation, i.e., on the blast-like CD4+CD8+ thymocytes.

  13. Investigation of the genes involved in antigenic switching at the vlsE locus in Borrelia burgdorferi: an essential role for the RuvAB branch migrase.

    PubMed

    Dresser, Ashley R; Hardy, Pierre-Olivier; Chaconas, George

    2009-12-01

    Persistent infection by pathogenic organisms requires effective strategies for the defense of these organisms against the host immune response. A common strategy employed by many pathogens to escape immune recognition and clearance is to continually vary surface epitopes through recombinational shuffling of genetic information. Borrelia burgdorferi, a causative agent of Lyme borreliosis, encodes a surface-bound lipoprotein, VlsE. This protein is encoded by the vlsE locus carried at the right end of the linear plasmid lp28-1. Adjacent to the expression locus are 15 silent cassettes carrying information that is moved into the vlsE locus through segmental gene conversion events. The protein players and molecular mechanism of recombinational switching at vlsE have not been characterized. In this study, we analyzed the effect of the independent disruption of 17 genes that encode factors involved in DNA recombination, repair or replication on recombinational switching at the vlsE locus during murine infection. In Neisseria gonorrhoeae, 10 such genes have been implicated in recombinational switching at the pilE locus. Eight of these genes, including recA, are either absent from B. burgdorferi, or do not show an obvious requirement for switching at vlsE. The only genes that are required in both organisms are ruvA and ruvB, which encode subunits of a Holliday junction branch migrase. Disruption of these genes results in a dramatic decrease in vlsE recombination with a phenotype similar to that observed for lp28-1 or vls-minus spirochetes: productive infection at week 1 with clearance by day 21. In SCID mice, the persistence defect observed with ruvA and ruvB mutants was fully rescued as previously observed for vlsE-deficient B. burgdorferi. We report the requirement of the RuvAB branch migrase in recombinational switching at vlsE, the first essential factor to be identified in this process. These findings are supported by the independent work of Lin et al. in the

  14. Cloning of a new gene encoding an antigen recognized by melanoma-specific HLA-A24-restricted tumor-infiltrating lymphocytes

    SciTech Connect

    Robbins, P.F.; El-Gamil, M.; Li, Y.F.

    1995-06-01

    The role of tumor-specific T cells in mediating the regression of metastatic melanoma has been suggested by the clinical response of patients to treatment with tumor-infiltrating lymphocytes (TIL). A number of Ags recognized by class I-restricted melanoma-specific T cells have recently been isolated, raising the hope that this will lead to the development of improved therapies. In this study, we report the cloning of a tumor Ag recognized by T cells from melanoma patient 888. Previously, we reported that TIL 888, grown from the tumor of this patient, recognized tyrosinase in an HLA-A24 -restricted fashion. This line, when infused into the autologous patient, resulted in complete regression of multiple metastases. Three years later, a second TIL line, TIL 1290, was isolated from a recurrent pelvic tumor. Infusion of a mixture of TIL 888 and TIL 1290 cell lines into the patient resulted in complete regression of a residual abdominal mass and the patient remains disease-free 2 yr later. The TIL 1290 cell line, which recognized melanoma in an HLAA-A24-restricted manner, failed to recognize tyrosinase. TIL 1290 was then used to screen an 888 melanoma cDNA library, and an Ag was isolated that did not correspond to any found in sequence databases. This gene, termed p15, was found to be expressed in a variety of normal tissues, and a peptide epitope recognized by TIL 1290 was found to represent the product of an nonmutated gene. Screening of additional cDNA pools resulted in the isolation of a second clone which stimulated TIL 1290. This clone also appeared to represent a transcript of the p15 gene, indicating that this gene may encode the predominant Ag recognized by TIL 1290. 27 refs., 4 figs., 5 tabs.

  15. IRRIGATION TO MAXIMIZE VACCINE ANTIGEN PRODUCTION IN PHARMACEUTICAL TOBACCO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biotechnology companies have engineered plants to produce recombinant proteins for therapeutic drugs and vaccines. Chlorogen, Inc. located in St. Louis, Missouri, inserted the protective antigen (PA) gene from Bacillus anthracis into tobacco (Nicotiana tabacum) chloroplasts to produce an anthrax va...

  16. Genetic Analysis and Detection of fliCH1 and fliCH12 Genes Coding for Serologically Closely Related Flagellar Antigens in Human and Animal Pathogenic Escherichia coli

    PubMed Central

    Beutin, Lothar; Delannoy, Sabine; Fach, Patrick

    2016-01-01

    The E. coli flagellar types H1 and H12 show a high serological cross-reactivity and molecular serotyping appears an advantageous method to establish a clear discrimination between these flagellar types. Analysis of fliCH1 and fliCH12 gene sequences showed that they were 97.5% identical at the nucleotide level. Because of this high degree of homology we developed a two-step real-time PCR detection procedure for reliable discrimination of H1 and H12 flagellar types in E. coli. In the first step, a real-time PCR assay for common detection of both fliCH1 and fliCH12 genes is used, followed in a second step by real-time PCR assays for specific detection of fliCH1 and fliCH12, respectively. The real-time PCR for common detection of fliCH1 and fliCH12 demonstrated 100% sensitivity and specificity as it reacted with all tested E. coli H1 and H12 strains and not with any of the reference strains encoding all the other 51 flagellar antigens. The fliCH1 and fliCH12 gene specific assays detected all E. coli H1 and all E. coli H12 strains, respectively (100% sensitivity). However, both assays showed cross-reactions with some flagellar type reference strains different from H1 and H12. The real-time PCR assays developed in this study can be used in combination for the detection and identification of E. coli H1 and H12 strains isolated from different sources. PMID:26913025

  17. Genome-wide association study identified novel genetic variant on SLC45A3 gene associated with serum levels prostate-specific antigen (PSA) in a Chinese population.

    PubMed

    Sun, Jielin; Tao, Sha; Gao, Yong; Peng, Tao; Tan, Aihua; Zhang, Haiying; Yang, Xiaobo; Qin, Xue; Hu, Yanling; Feng, Junjie; Kim, Seong-Tae; Lin, Xiaoling; Wu, Yongming; Zhang, Ju; Li, Zhixian; Li, Li; Mo, Linjian; Liang, Zhengjia; Shi, Deyi; Huang, Zhang; Huang, Xianghua; Liu, Ming; Liu, Qian; Zhang, Shijun; Lilly Zheng, S; Xu, Jianfeng; Mo, Zengnan

    2013-04-01

    Prostate-specific antigen (PSA) is a commonly used cancer biomarker for prostate cancer, and is often included as part of routine physical examinations in China. Serum levels of PSA may be influenced by genetic factors as well as other factors. A genome-wide association study (GWAS) conducted in a European population successfully identified six genetic loci that were significantly associated with PSA level. In this study, we aimed to identify common genetic variants that are associated with serum level of PSA in a Chinese population. We also evaluated the effects of those variants by creating personalized PSA cutoff values. A two-stage GWAS of PSA level was performed among men age 20-69 years and self-reported cancer-free participants that underwent routine physical examinations at several hospitals in Guangxi Province, China. Single nucleotide polymorphisms (SNPs) significantly associated with PSA levels in the first stage of sample (N = 1,999) were confirmed in the second stage of sample (N = 1,496). Multivariate linear regression was used to assess the independent contribution of confirmed SNPs and known covariates, such as age, to the level of PSA. SNPs in three regions were significantly associated with levels of PSA in this two-stage GWAS, and had combined P values between 4.62 × 10(-17) and 6.45 × 10(-37). The three regions are located on 1q32.1 at SLC45A3, 10q11.23 at MSMB, and 19q13.33 at KLK3. The region 1q32.1 at SLC45A3 was identified as a novel locus. Genetic variants contributed significantly more to the variance of PSA level than known covariates such as age. Personalized cutoff values of serum PSA, calculated based on the inheritance of these associated SNPs, differ considerably among individuals. Identification of these genetic markers provides new insight into the molecular mechanisms of PSA. Taking individual variation into account, these genetic variants may improve the performance of PSA to predict prostate cancer. PMID:23269536

  18. Induction of antigen-specific cytotoxic T-cell response by dendritic cells generated from ecto-mesenchymal stem cells infected with an adenovirus containing the MAGE-D4a gene

    PubMed Central

    HU, SHIJIE; LI, BING; SHEN, XUEFENG; ZHANG, RUI; GAO, DAKUAN; GUO, QINGDONG; JIN, YAN; FEI, ZHOU

    2016-01-01

    The present study aimed to investigate the feasibility of using ecto-mesenchymal stem cell (EMSC)-derived dendritic cells (DCs) for glioma immunotherapy following infection by a recombinant adenovirus containing the melanoma-associated antigen D4a (MAGE-D4a) gene. The ex vivo cultured EMSCs were infected by the adenoviral plasmid containing MAGE-D4a (pAd/MAGE-D4a). Efficiency of transfection was evaluated through the detection of green fluorescent protein-marked MAGE-D4a. The MAGE-EMSCs were induced to differentiate into DCs, termed as MAGE-EMSCs-DCs. The morphology was subsequently analyzed under a microscope, and methyl thiazolyl tetrazolium (MTT) and interferon-γ (IFN-γ) assays were performed to analyze the cytotoxicity of the MAGE-EMSC-DCs on the human glioma U251 cell line. Following purification by magnetic-activated cell sorting, the EMSCs grew into swirls, with a long spindle shape and were fibroblast-like. The gene transfected with recombinant adenovirus vectors maintained high and stable expression levels of MAGE-D4a, and its efficiency was increased in a multiplicity of infection-dependent manner. The results of the MTT assay indicated that the T cells, primed by the recombinant MAGE-D4a-infected EMSC-DCs in vitro, recognized MAGE-D4a-expressing tumor cell lines in a human leukocyte antigen class I-restricted manner, and evoked a higher cytotoxic T cell (CTL) response. The CTL response induced by the MAGE-EMSC-DCs, co-cultured with the U251 cells for 24 h, produced 765.0 pg/ml IFN-γ, which was significantly greater when compared to the control wells. T lymphocytes stimulated by MAGE-EMSC-DCs evoke a higher CTL response to human glioma cell lines, and may serve as a promising therapeutic modality for the treatment of MAGE-D4a-expressing glioma. PMID:27073570

  19. Genomic Methylation Inhibits Expression of Hepatitis B Virus Envelope Protein in Transgenic Mice: A Non-Infectious Mouse Model to Study Silencing of HBV Surface Antigen Genes

    PubMed Central

    Graumann, Franziska; Churin, Yuri; Tschuschner, Annette; Reifenberg, Kurt; Glebe, Dieter; Roderfeld, Martin; Roeb, Elke

    2015-01-01

    Objective The Hepatitis B virus genome persists in the nucleus of virus infected hepatocytes where it serves as template for viral mRNA synthesis. Epigenetic modifications, including methylation of the CpG islands contribute to the regulation of viral gene expression. The present study investigates the effects of spontaneous age dependent loss of hepatitis B surface protein- (HBs) expression due to HBV-genome specific methylation as well as its proximate positive effects in HBs transgenic mice. Methods Liver and serum of HBs transgenic mice aged 5–33 weeks were analyzed by Western blot, immunohistochemistry, serum analysis, PCR, and qRT-PCR. Results From the third month of age hepatic loss of HBs was observed in 20% of transgenic mice. The size of HBs-free area and the relative number of animals with these effects increased with age and struck about 55% of animals aged 33 weeks. Loss of HBs-expression was strongly correlated with amelioration of serum parameters ALT and AST. In addition lower HBs-expression went on with decreased ER-stress. The loss of surface protein expression started on transcriptional level and appeared to be regulated epigenetically by DNA methylation. The amount of the HBs-expression correlated negatively with methylation of HBV DNA in the mouse genome. Conclusions Our data suggest that methylation of specific CpG sites controls gene expression even in HBs-transgenic mice with truncated HBV genome. More important, the loss of HBs expression and intracellular aggregation ameliorated cell stress and liver integrity. Thus, targeted modulation of HBs expression may offer new therapeutic approaches. Furthermore, HBs-transgenic mice depict a non-infectious mouse model to study one possible mechanism of HBs gene silencing by hypermethylation. PMID:26717563

  20. MHC Class II Auto-Antigen Presentation is Unconventional

    PubMed Central

    Sadegh-Nasseri, Scheherazade; Kim, AeRyon

    2015-01-01

    Antigen presentation is highly critical in adoptive immunity. Only by interacting with antigens presented by major histocompatibility complex class II molecules, helper T cells can be stimulated to fight infections or diseases. The degradation of a full protein into small peptide fragments bound to class II molecules is a dynamic, lengthy process consisting of many steps and chaperons. Deregulation in any step of antigen processing could lead to the development of self-reactive T cells or defective immune response to pathogens. Indeed, human leukocyte antigens class II genes are the predominant contributors to susceptibility to autoimmune diseases. Conventional antigen-processing calls for internalization of extracellular antigens followed by processing and epitope selection within antigen-processing subcellular compartments, enriched with all necessary accessory molecules, processing enzymes, and proper pH and denaturing conditions. However, recent data examining the temporal relationship between antigen uptakes, processing, and epitope selection revealed unexpected characteristics for auto-antigenic epitopes, which were not shared with antigenic epitopes from pathogens. This review provides a discussion of the relevance of these findings to the mechanisms of autoimmunity. PMID:26257739

  1. Constitutive activation of Epstein-Barr virus (EBV) nuclear antigen 1 gene transcription by IRF1 and IRF2 during restricted EBV latency.

    PubMed Central

    Schaefer, B C; Paulson, E; Strominger, J L; Speck, S H

    1997-01-01

    The Epstein-Barr virus (EBV) EBNA1 gene promoter active in the type I program of restricted viral latency was recently identified and shown to reside in the viral BamHI Q fragment. This promoter, Qp, is active in a wide variety of cell lines and has an architecture reminiscent of eukaryotic housekeeping gene promoters (B. C. Schaefer, J. L. Strominger, and S. H. Speck, Proc. Natl. Acad. Sci. USA 92:10565-10569, 1995; B. C. Schaefer, J. L. Strominger, and S. H. Speck, Mol. Cell. Biol. 17:364-377, 1997). Here we demonstrate by deletion analysis that the important cis-acting elements regulating Qp are clustered in a relatively small region (ca. 80 bp) surrounding the site of transcription initiation. Immediately upstream of the site of initiation is a region which is protected from DNase I digestion by crude nuclear extracts. Electrophoretic mobility shift analyses (EMSA) employing probes spanning this region demonstrated the presence of two major protein complexes. Deletion analysis of Qp demonstrated that at least one of these complexes plays an important role in Qp activity. Evidence that interferon response factor 2 (IRF2) is a major constituent of the most prominent EMSA complex and that IRF1 may be a minor component of this complex is presented. Transfections into IRF1-/-, IRF2-/-, and IRF1,2-/- fibroblasts demonstrated that absence of both IRF1 and IRF2 reduced Qp activity to approximately the same extent as mutation of the IRF-binding site in Qp, strongly implicating IRF2, and perhaps IRF1, in the regulation of Qp activity. Notably, transcription from Qp was not inducible by either alpha or gamma interferon in EBV-negative B cells but rather was shown to be constitutively activated by IRF1 and IRF2. This observation suggests that IRF1 and IRF2 have a previously unrecognized role as constitutive activators of specific genes. Additionally, data presented indicate that a protein complex containing the nonhistone architectural protein HMG-I(Y) binds to the region

  2. Deep Sequencing and Circos Analyses of Antibody Libraries Reveal Antigen-driven Selection of Ig VH Genes during HIV-1 Infection

    PubMed Central

    Xiao, Madelyne; Ponraj, Prabakaran; Chen, Weizao; Kessing, Bailey; Dimitrov, Dimiter S.

    2013-01-01

    The vast diversity of antibody repertoires is largely attributed to heavy chain (VH) recombination of variable (V), diversity (D) and joining (J) gene segments. We used 454 sequencing information of the variable domains of the antibody heavy chain repertoires from neonates, normal adults and an HIV-1-infected individual, to analyze, with Circos software, the VDJ pairing patterns at birth, adulthood and a time-dependent response to HIV-1 infection. Our comparative analyses of the Ig VDJ repertoires from these libraries indicated that, from birth to adulthood, VDJ recombination patterns remain the same with some slight changes, whereas some VH families are selected and preferentially expressed after long-term infection with HIV-1. We also demonstrated that the immune system responds to HIV-1 chronic infection by selectively expanding certain HV families in an attempt to combat infection. Our findings may have implications for understanding immune responses in pathology as well as for development of new therapeutics and vaccines. PMID:24158018

  3. An unbiased genome-wide Mycobacterium tuberculosis gene expression approach to discover antigens targeted by human T cells expressed during pulmonary infection.

    PubMed

    Commandeur, Susanna; van Meijgaarden, Krista E; Prins, Corine; Pichugin, Alexander V; Dijkman, Karin; van den Eeden, Susan J F; Friggen, Annemieke H; Franken, Kees L M C; Dolganov, Gregory; Kramnik, Igor; Schoolnik, Gary K; Oftung, Fredrik; Korsvold, Gro Ellen; Geluk, Annemieke; Ottenhoff, Tom H M

    2013-02-15

    Mycobacterium tuberculosis is responsible for almost 2 million deaths annually. Mycobacterium bovis bacillus Calmette-Guérin, the only vaccine available against tuberculosis (TB), induces highly variable protection against TB, and better TB vaccines are urgently needed. A prerequisite for candidate vaccine Ags is that they are immunogenic and expressed by M. tuberculosis during infection of the primary target organ, that is, the lungs of susceptible individuals. In search of new TB vaccine candidate Ags, we have used a genome-wide, unbiased Ag discovery approach to investigate the in vivo expression of 2170 M. tuberculosis genes during M. tuberculosis infection in the lungs of mice. Four genetically related but distinct mouse strains were studied, representing a spectrum of TB susceptibility controlled by the supersusceptibility to TB 1 locus. We used stringent selection approaches to select in vivo-expressed M. tuberculosis (IVE-TB) genes and analyzed their expression patterns in distinct disease phenotypes such as necrosis and granuloma formation. To study the vaccine potential of these proteins, we analyzed their immunogenicity. Several M. tuberculosis proteins were recognized by immune cells from tuberculin skin test-positive, ESAT6/CFP10-responsive individuals, indicating that these Ags are presented during natural M. tuberculosis infection. Furthermore, TB patients also showed responses toward IVE-TB Ags, albeit lower than tuberculin skin test-positive, ESAT6/CFP10-responsive individuals. Finally, IVE-TB Ags induced strong IFN-γ(+)/TNF-α(+) CD8(+) and TNF-α(+)/IL-2(+) CD154(+)/CD4(+) T cell responses in PBMC from long-term latently M. tuberculosis-infected individuals. In conclusion, these IVE-TB Ags are expressed during pulmonary infection in vivo, are immunogenic, induce strong T cell responses in long-term latently M. tuberculosis-infected individuals, and may therefore represent attractive Ags for new TB vaccines. PMID:23319735

  4. Sequence analysis of the Bs-Ag1 gene of Baylisascaris schroederi from the giant panda and an evaluation of the efficacy of a recombinant Baylisascaris schroederi Bs-Ag1 antigen in mice.

    PubMed

    He, Guangzhi; Chen, Sijie; Wang, Tao; Yan, Yubo; Zhang, Zhihe; Li, Desheng; Yu, Hua; Xie, Yue; Wang, Chengdong; Gu, Xiaobin; Wang, Shuxian; Peng, Xuerong; Yang, Guangyou

    2012-07-01

    The Baylisascaris schroederi infection rate among wild giant pandas may reach over 50% or even 100%, making it one of the leading causes of death from primary or secondary infection in wild populations. Until now, little was known about how protective immunity to B. schroederi infection could be achieved. The present study was conducted to evaluate the immunogenicity and protective efficacy of recombinant Bs-Ag1 from B. schroederi, by cloning the full-length Bs-Ag1 gene of B. schroederi and expressing it in a heterologous host, Escherichia coli BL21. In mice vaccinated with rBs-Ag1 coupled with Freund's complete adjuvant (FCA), there was a significant reduction (69.2%) in the recovery of challenged B. schroederi L3 compared with either nonvaccinated controls or mice vaccinated with FCA alone. Our study supports the use of Bs-Ag1 as a potential candidate for vaccination against B. schroederi infection and provides basic data for further vaccination trials with mixtures of antigens (with Bs-Ag2 and Bs-Ag3) to B. schroederi. PMID:22339267

  5. Polyomavirus T Antigens Activate an Antiviral State

    PubMed Central

    Giacobbi, Nicholas S.; Gupta, Tushar; Coxon, Andrew; Pipas, James M.

    2014-01-01

    Ectopic expression of Simian Virus 40 (SV40) large T antigen (LT) in mouse embryonic fibroblasts (MEFs) increased levels of mRNAs encoding interferon stimulated genes (ISGs). The mechanism by which T antigen increases levels of ISGs in MEFs remains unclear. We present evidence that expression of T antigen from SV40, Human Polyomaviruses BK (BKV) or JC (JCV) upregulate production of ISGs in MEFs, and subsequently result in an antiviral state, as determined by inhibition of VSV or EMCV growth. The first 136 amino acids of LT are sufficient for these activities. Furthermore, increased ISG expression and induction of the antiviral state requires STAT1. Finally, the RB binding motif of LT is necessary for activation of STAT1. We conclude that the induction of the STAT1 mediated innate immune response in MEFs is a common feature shared by SV40, BKV and JCV. PMID:25589241

  6. Probing the human antibody repertoire to exogenous antigens: Characterization of the H and L chain V region gene segments from anti-hepatitis B virus antibodies

    SciTech Connect

    Andris, J.S.; Capra, J.D. ); Ehrlich, P.H.; Oestberg, L. )

    1992-12-15

    Structural studies of human antibody V regions have been largely limited to those involving the fetal repertoire, autoantibodies, and malignant cell rearrangements, leaving the normal' repertoire relatively unexplored. In this study the authors describe the nucleotide sequences of the H and L chain V regions of four antibodies specific for the surface Ag of the hepatitis B virus. Monoclonal cell lines were derived from healthy individuals who received standard immunizations with the serum-derived or recombinant hepatitis B virus vaccines by fusion of PBL to a heterohybridoma cell line, SPAZ-4. They utilized the polymerase chain reaction to aimplify the H and L chain V regions for cloning and sequencing. The four antibodies express the following V region combinations: V[sub H]III/V[lambda]V, V[sub H]III/V[kappa]II, V[sub H]IV/V[kappa]I, V[sub H]V/V[lambda]III. When compared to germline genes with the closest sequence homology, all of the V regions appear to have undergone somatic mutation, ranging from 3.4 to 11.3% for the H chain, and 5.1 to 9.2% for the L chain. Analysis of the mutations shows them to be typical for an Ag-driven immune response. 50 refs., 3 figs., 2 tabs.

  7. Deep sequencing and Circos analyses of antibody libraries reveal antigen-driven selection of Ig VH genes during HIV-1 infection.

    PubMed

    Xiao, Madelyne; Prabakaran, Ponraj; Chen, Weizao; Kessing, Bailey; Dimitrov, Dimiter S

    2013-12-01

    The vast diversity of antibody repertoires is largely attributed to heavy chain (V(H)) recombination of variable (V), diversity (D) and joining (J) gene segments. We used 454 sequencing information of the variable domains of the antibody heavy chain repertoires from neonates, normal adults and an HIV-1-infected individual, to analyze, with Circos software, the VDJ pairing patterns at birth, adulthood and a time-dependent response to HIV-1 infection. Our comparative analyses of the Ig VDJ repertoires from these libraries indicated that, from birth to adulthood, VDJ recombination patterns remain the same with some slight changes, whereas some V(H) families are selected and preferentially expressed after long-term infection with HIV-1. We also demonstrated that the immune system responds to HIV-1 chronic infection by selectively expanding certain HV families in an attempt to combat infection. Our findings may have implications for understanding immune responses in pathology as well as for development of new therapeutics and vaccines. PMID:24158018

  8. The mutation G298A-->Ala100Thr on the coding sequence of the Duffy antigen/chemokine receptor gene in non-caucasian Brazilians.

    PubMed

    Estalote, Angela Cristina; Proto-Siqueira, Rodrigo; Silva, Wilson Araújo Da; Zago, Marco Antonio; Palatnik, Marcos

    2005-01-01

    Ala100Thr has been suggested to be a Caucasian genetic marker on the FY*B allele. As the Brazilian population has arisen from miscegenation among Portuguese, Africans, and Indians, this mutation could possibly be found in Euro- and Afro-Brazilians, or in Brazilian Indians. Fifty-three related individuals and a random sample of 100 subjects from the Brazilian population were investigated using the polymerase chain reaction and four restriction fragment length polymorphisms. Confirming the working hypothesis, among the related individuals three Afro-Brazilians (two of them a mother and daughter) and a woman of Amerindian descent had the Ala100Thr mutation on the FY*B allele. Five non-related Euro-Brazilians also carried the mutation. All nine individuals presented the Fy(a-b+) phenotype. We conclude that the Ala100Thr mutation can occur in populations other than Caucasians and that this mutation does not affect Duffy expression on red blood cells. Gene frequencies for this allele in the non-related individuals were in agreement with those of other populations. The Duffy frequencies of two Amerindian tribes were also investigated. PMID:16110438

  9. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia

    SciTech Connect

    Epstein, L.M.; Forney, J.D.

    1984-08-01

    A screening procedure was devised for the isolation of X-ray-induced mutations affecting the expression of the A immobilization antigen (i-antigen) in Paramecium tetraurelia. Two of the mutations isolated by this procedure proved to be in modifier genes. The two genes are unlinked to each other and unlinked to the structural A i-antigen gene. These are the first modifier genes identified in a Paramecium sp. that affect surface antigen expression. Another mutation was found to be a deletion of sequences just downstream from the A i-antigen gene. In cells carrying this mutation, the A i-antigen gene lies in close proximity to the end of a macronuclear chromosome. The expression of the A i-antigen is not affected in these cells, demonstrating that downstream sequences are not important for the regulation and expression of the A i-antigen gene. A stable cell line was also recovered which shows non-Mendelian inheritance of a macronuclear deletion of the A i-antigen gene. This mutant does not contain the gene in its macronucleus, but contains a complete copy of the gene in its micronucleus. In the cytoplasm of wild-type animals, the micronuclear gene is included in the developing macronucleus; in the cytoplasm of the mutant, the incorporation of the A i-antigen gene into the macronucleus is inhibited. This is the first evidence that a mechanism is available in ciliates to control the expression of a gene by regulating its incorporation into developing macronuclei.

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

    PubMed

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

    2016-07-01

    Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our phylogenetic analysis, Thai msa-1 gene sequences occurred in 18 clades; seven among them were composed of sequences exclusively from Thailand. To investigate differential antigenicity of isolated MSA-1 proteins, we expressed and purified eight recombinant MSA-1 (rMSA-1) proteins, including an rMSA-1 from B. bovis Texas (T2Bo) strain and seven rMSA-1 proteins based on the Thai msa-1 sequences. When these antigens were analyzed in a western blot assay, anti-T2Bo cattle serum strongly reacted with the rMSA-1 from T2Bo, as well as with three other rMSA-1 proteins that shared 54.9-68.4% sequence similarity with T2Bo MSA-1. In contrast, no or weak reactivity was observed for the remaining rMSA-1 proteins, which shared low sequence similarity (35.0-39.7%) with T2Bo MSA-1. While demonstrating the high genetic diversity of the B. bovis msa-1 gene in Thailand, the present findings suggest that the genetic diversity results in antigenicity variations among the MSA-1 antigens of B. bovis in Thailand. PMID:27101782

  11. The MS Risk Allele of CD40 Is Associated with Reduced Cell-Membrane Bound Expression in Antigen Presenting Cells: Implications for Gene Function

    PubMed Central

    Field, Judith; Shahijanian, Fernando; Schibeci, Stephen; Johnson, Laura; Gresle, Melissa; Laverick, Louise; Parnell, Grant; Stewart, Graeme; McKay, Fiona; Kilpatrick, Trevor; Butzkueven, Helmut; Booth, David

    2015-01-01

    Human genetic and animal studies have implicated the costimulatory molecule CD40 in the development of multiple sclerosis (MS). We investigated the cell specific gene and protein expression variation controlled by the CD40 genetic variant(s) associated with MS, i.e. the T-allele at rs1883832. Previously we had shown that the risk allele is expressed at a lower level in whole blood, especially in people with MS. Here, we have defined the immune cell subsets responsible for genotype and disease effects on CD40 expression at the mRNA and protein level. In cell subsets in which CD40 is most highly expressed, B lymphocytes and dendritic cells, the MS-associated risk variant is associated with reduced CD40 cell-surface protein expression. In monocytes and dendritic cells, the risk allele additionally reduces the ratio of expression of full-length versus truncated CD40 mRNA, the latter encoding secreted CD40. We additionally show that MS patients, regardless of genotype, express significantly lower levels of CD40 cell-surface protein compared to unaffected controls in B lymphocytes. Thus, both genotype-dependent and independent down-regulation of cell-surface CD40 is a feature of MS. Lower expression of a co-stimulator of T cell activation, CD40, is therefore associated with increased MS risk despite the same CD40 variant being associated with reduced risk of other inflammatory autoimmune diseases. Our results highlight the complexity and likely individuality of autoimmune pathogenesis, and could be consistent with antiviral and/or immunoregulatory functions of CD40 playing an important role in protection from MS. PMID:26068105

  12. Calcitonin Gene-Related Peptide-Exposed Endothelial Cells Bias Antigen Presentation to CD4+ T Cells toward a Th17 Response.

    PubMed

    Ding, Wanhong; Stohl, Lori L; Xu, Linghui; Zhou, Xi K; Manni, Michela; Wagner, John A; Granstein, Richard D

    2016-03-01

    Calcitonin gene-related peptide (CGRP) is a neuropeptide with well-established immunomodulatory functions. CGRP-containing nerves innervate dermal blood vessels and lymph nodes. We examined whether CGRP regulates the outcome of Ag presentation by Langerhans cells (LCs) to T cells through actions on microvascular endothelial cells (ECs). Exposure of primary murine dermal microvascular ECs (pDMECs) to CGRP followed by coculture with LCs, responsive CD4(+) T cells and Ag resulted in increased production of IL-6 and IL-17A accompanied by inhibition of IFN-γ, IL-4, and IL-22 compared with wells containing pDMECs treated with medium alone. Physical contact between ECs and LCs or T cells was not required for this effect and, except for IL-4, we demonstrated that IL-6 production by CGRP-treated pDMECs was involved in these effects. CD4(+) cells expressing cytoplasmic IL-17A were increased, whereas cells expressing cytoplasmic IFN-γ or IL-4 were decreased by the presence of CGRP-treated pDMECs. In addition, the level of retinoic acid receptor-related orphan receptor γt mRNA was significantly increased, whereas T-bet and GATA3 expression was inhibited. Immunization at the site of intradermally administered CGRP led to a similar bias in CD4(+) T cells from draining lymph node cells toward IL-17A and away from IFN-γ. Actions of nerve-derived CGRP on ECs may have important regulatory effects on the outcome of Ag presentation with consequences for the expression of inflammatory skin disorders involving Th17 cells. PMID:26829986

  13. Presentation of hepatocellular antigens

    PubMed Central

    Grakoui, Arash; Crispe, Ian Nicholas

    2016-01-01

    The liver is an organ in which antigen-specific T-cell responses manifest a bias toward immune tolerance. This is clearly seen in the rejection of allogeneic liver transplants, and multiple other phenomena suggest that this effect is more general. These include tolerance toward antigens introduced via the portal vein, immune failure to several hepatotropic viruses, the lack of natural liver-stage immunity to malaria parasites, and the frequent metastasis of cancers to the liver. Here we review the mechanisms by which T cells engage with hepatocellular antigens, the context in which such encounters occur, and the mechanisms that act to suppress a full T-cell response. While many mechanisms play a role, we will argue that two important processes are the constraints on the cross-presentation of hepatocellular antigens, and the induction of negative feedback inhibition driven by interferons. The constant exposure of the liver to microbial products from the intestine may drive innate immunity, rendering the local environment unfavorable for specific T-cell responses through this mechanism. Nevertheless, tolerance toward hepatocellular antigens is not monolithic and under specific circumstances allows both effective immunity and immunopathology. PMID:26924525

  14. Pathways of Antigen Processing

    PubMed Central

    Blum, Janice S.; Wearsch, Pamela A.; Cresswell, Peter

    2014-01-01

    T cell recognition of antigen presenting cells depends on their expression of a spectrum of peptides bound to Major Histocompatibility Complex class I (MHC-I) and class II (MHC-II) molecules. Conversion of antigens from pathogens or transformed cells into MHC-I and MHC-II-bound peptides is critical for mounting protective T cell responses, and similar processing of self proteins is necessary to establish and maintain tolerance. Cells use a variety of mechanisms to acquire protein antigens, from translation in the cytosol to variations on the theme of endocytosis, and to degrade them once acquired. In this review we highlight the aspects of MHC-I and MHC-II biosynthesis and assembly that have evolved to intersect these pathways and sample the peptides that are produced. PMID:23298205

  15. Lipid antigens in immunity

    PubMed Central

    Dowds, C. Marie; Kornell, Sabin-Christin

    2014-01-01

    Lipids are not only a central part of human metabolism but also play diverse and critical roles in the immune system. As such, they can act as ligands of lipid-activated nuclear receptors, control inflammatory signaling through bioactive lipids such as prostaglandins, leukotrienes, lipoxins, resolvins, and protectins, and modulate immunity as intracellular phospholipid- or sphingolipid-derived signaling mediators. In addition, lipids can serve as antigens and regulate immunity through the activation of lipid-reactive T cells, which is the topic of this review. We will provide an overview of the mechanisms of lipid antigen presentation, the biology of lipid-reactive T cells, and their contribution to immunity. PMID:23999493

  16. Antigen detection systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissue using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular methodology is chosen ...

  17. Antigen smuggling in tuberculosis.

    PubMed

    Hudrisier, Denis; Neyrolles, Olivier

    2014-06-11

    The importance of CD4 T lymphocytes in immunity to M. tuberculosis is well established; however, how dendritic cells activate T cells in vivo remains obscure. In this issue of Cell Host & Microbe, Srivastava and Ernst (2014) report a mechanism of antigen transfer for efficient activation of antimycobacterial T cells. PMID:24922567

  18. Antigen detection systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissues or other specimens, using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular m...

  19. Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on antibody-mediated immune response and gene expression of pattern recognition receptors and cytokines in broiler chickens immunized with T-cell dependent antigens.

    PubMed

    Alizadeh, M; Rodriguez-Lecompte, J C; Echeverry, H; Crow, G H; Slominski, B A

    2016-04-01

    This study evaluated the effect of yeast-derived products on innate and antibody mediated immune response in broiler chickens following immunization with sheep red blood cells (SRBC) and bovine serum albumin (BSA). One-day-old male broiler chickens (Ross-308) were randomly assigned to 6 dietary treatments of 9 replicate cages of 5 birds each per treatment. Dietary treatments consisted of a Control diet without antibiotic, and diets containing 11 mg/kg of virginiamycin, 0.25% of yeast cell wall (YCW), 0.2% of a commercial product Maxi-Gen Plus containing processed yeast and nucleotides, 0.05% of nucleotides, or a diet containing 10% of DDGS. On days 21 and 28 post-hatching, 5 birds per treatment were immunized intramuscularly with both SRBC and BSA. One week after each immunization, blood samples were collected. Serum samples were analyzed by hemagglutination test for antibody response to SRBC, and by ELISA for serum IgM and IgG response to BSA. On d 35, 5 birds per treatment were euthanized and the tissue samples from the cecal tonsils were collected to assess the gene expression of toll-like receptors TLR2b, TLR4, and TLR21, monocyte mannose receptor (MMR), and cytokines IL-10, IL-13, IL-4, IL-12p35, and IFN-γ. The results for gene expression analysis demonstrated that the diet supplemented with YCW increased the expression of TLR2b and T-helper type 2 cytokines IL-10, IL-4, and IL-13 relative to the Control; and the expression of TLR4 and IL-13 was upregulated in the nucleotide-containing diet. However, the diets containing antibiotics or Maxi-Gen Plus downregulated the expression of IFN-γ compared to the control. The primary antibody response to SRBC was not affected by diets. However, the diet containing YCW increased the secondary antibody response to SRBC compared to the antibiotic treatment. Neither primary nor secondary IgG and IgM response against BSA were affected by diets. In conclusion, supplementation of the diet with YCW stimulated Th2 cell

  20. Aspergillus antigen skin test (image)

    MedlinePlus

    The aspergillus antigen skin test determines whether or not a person has been exposed to the mold aspergillus. It is performed by injecting an aspergillus antigen under the skin with a needle. After 48 ...

  1. Expression of Plasmodium falciparum surface antigens in Escherichia coli.

    PubMed Central

    Ardeshir, F; Flint, J E; Reese, R T

    1985-01-01

    The asexual blood stages of the human malarial parasite Plasmodium falciparum produce many antigens, only some of which are important for protective immunity. Most of the putative protective antigens are believed to be expressed in schizonts and merozoites, the late stages of the asexual cycle. With the aim of cloning and characterizing genes for important parasite antigens, we used late-stage P. falciparum mRNA to construct a library of cDNA sequences inserted in the Escherichia coli expression vector pUC8. Nine thousand clones from the expression library were immunologically screened in situ with serum from Aotus monkeys immune to P. falciparum, and 95 clones expressing parasite antigens were identified. Mice were immunized with lysates from 49 of the bacterial clones that reacted with Aotus sera, and the mouse sera were tested for their reactivity with parasite antigens by indirect immunofluorescence, immunoprecipitation, and immunoblotting assays. Several different P. falciparum antigens were identified by these assays. Indirect immunofluorescence studies of extracellular merozoites showed that three of these antigens appear to be located on the merozoite surface. Thus, we have identified cDNA clones to three different P. falciparum antigens that may be important in protective immunity. Images PMID:3887406

  2. 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

  3. Cancer testis antigen and immunotherapy

    PubMed Central

    Krishnadas, Deepa Kolaseri; Bai, Fanqi; Lucas, Kenneth G

    2013-01-01

    The identification of cancer testis (CT) antigens has been an important advance in determining potential targets for cancer immunotherapy. Multiple previous studies have shown that CT antigen vaccines, using both peptides and dendritic cell vaccines, can elicit clinical and immunologic responses in several different tumors. This review details the expression of melanoma antigen family A, 1 (MAGE-A1), melanoma antigen family A, 3 (MAGE-A3), and New York esophageal squamous cell carcinoma-1 (NY-ESO-1) in various malignancies, and presents our current understanding of CT antigen based immunotherapy.

  4. Genetic Transfer of Shigella flexneri Antigens to Escherichia coli K-12 1

    PubMed Central

    Formal, S. B.; Gemski, P.; Baron, L. S.; Labrec, E. H.

    1970-01-01

    The genes controlling synthesis of Shigella flexneri group- and type-specific antigens were transferred to Escherichia coli K-12 recipients by conjugation with an S. flexneri Hfr. After mating E. coli with an Hfr strain of S. flexneri 2a and selecting for his+ recombinants, a high proportion of the E. coli hybrids agglutinated in S. flexneri grouping serum. None of these hybrids expressed S. flexneri type-specific antigen II. When an E. coli his+ hybrid possessing the S. flexneri group antigen was remated with the same Hfr with selection for pro+ hybrids, a high proportion now expressed the type-specific antigen as well as the previously inherited group antigen. If such crosses were performed in reverse order (i.e., pro+ followed by his+ selection), a different pattern of serological behavior was observed. None of the pro+ hybrids showed the type-specific antigen. Subsequent mating for his+ resulted in hybrids with both the group- and type-specific antigens. These results show that genes controlling the synthesis of S. flexneri group antigen (linked to the his locus) and type-specific antigen (linked to the pro locus) are widely separated on the chromosome. Expression of the type-specific antigen II depends on the presence of the group antigen. Images PMID:16557729

  5. Soy milk digestion extract inhibits progression of prostate cancer cell growth via regulation of prostate cancer‑specific antigen and cell cycle-regulatory genes in human LNCaP cancer cells.

    PubMed

    Kang, Nam-Hee; Shin, Hee-Chang; Oh, Seunghyun; Lee, Kyun-Hee; Lee, Yoon-Bok; Choi, Kyung-Chul

    2016-08-01

    Soy milk, which is produced from whole soybeans, contains a variety of biologically active components. Isoflavones are a class of soy-derived phytoestrogens with beneficial effects, among which genistein (GEN) has been previously indicated to reduce the risk of prostate cancer. The present study evaluated the effects of soy milk digestion extract (SMD) on the progression of prostate cancer via the estrogen receptor (ER)β in human LNCaP prostate cancer cells. To evaluate the effects of SMD (daizein, 1.988 mg/100g, glycitein, 23.537 mg/100 g and GEN, 0.685 mg/100g) on cell proliferation, LNCaP cells were cultured in media containing vehicle (0.1% dimethyl sulfoxide), 17β‑estradiol (E2; 2.7x10‑7 mg/ml), GEN (2.7x10-2 mg/ml) of SMD (total aglycon concentration, 0.79 mg/ml), after which the cell viability was examined using an MTT assay. The cell viability was significantly elevated by E2 (by 45±0.18%), while it was markedly reduced by GEN (73.2±0.03%) or SMD (74.8±0.09%). Semi‑quantitative reverse transcription polymerase chain reaction analysis was performed to assess the mRNA expression levels of target genes, including ERβ, prostate cancer‑specific antigen (PSA) and cell cycle regulators p21, Cyclin D1 and cyclin-dependent kinase (CDK)4. The expression of ERβ was almost completely diminished by E2, whereas it was significantly elevated by SMD. In addition, the expression levels of PSA were considerably reduced by SMD. The expression of p21 was significantly elevated by SMD, while it was markedly reduced by E2. Of note, the expression levels of Cyclin D1 and CDK4 were considerably elevated by E2, while being significantly reduced by GEN and SMD. All of these results indicated that SMD may inhibit the proliferation of human prostate cancer cells via regulating the expression of ERβ, PSA, p21, Cyclin D1 and CDK4 in an ER-dependent manner. PMID:27315510

  6. Antigenic Relationships among Human Pathogenic Orientia tsutsugamushi Isolates from Thailand

    PubMed Central

    Nawtaisong, Pruksa; Tanganuchitcharnchai, Ampai; Smith, Derek J.; Day, Nicholas P. J.; Paris, Daniel H.

    2016-01-01

    Background Scrub typhus is a common cause of undiagnosed febrile illness in certain tropical regions, but can be easily treated with antibiotics. The causative agent, Orientia tsutsugamushi, is antigenically variable which complicates diagnosis and efforts towards vaccine development. Methodology/Principal Findings This study aimed to dissect the antigenic and genetic relatedness of O. tsutsugamushi strains and investigate sero-diagnostic reactivities by titrating individual patient sera against their O. tsutsugamushi isolates (whole-cell antigen preparation), in homologous and heterologous serum-isolate pairs from the same endemic region in NE Thailand. The indirect immunofluorescence assay was used to titrate Orientia tsutsugamushi isolates and human sera, and a mathematical technique, antigenic cartography, was applied to these data to visualise the antigenic differences and cross-reactivity between strains and sera. No functional or antigen-specific analyses were performed. The antigenic variation found in clinical isolates was much less pronounced than the genetic differences found in the 56kDa type-specific antigen genes. The Karp-like sera were more broadly reactive than the Gilliam-like sera. Conclusions/Significance Antigenic cartography worked well with scrub typhus indirect immunofluorescence titres. The data from humoral responses suggest that a Karp-like strain would provide broader antibody cross-reactivity than a Gilliam-like strain. Although previous exposure to O. tsutsugamushi could not be ruled out, scrub typhus patient serum antibody responses were characterised by strong homologous, but weak heterologous antibody titres, with little evidence for cross-reactivity by Gilliam-like sera, but a broader response from some Karp-like sera. This work highlights the importance of antigenic variation in O. tsutsugamushi diagnosis and determination of new serotypes. PMID:27248711

  7. Cancer/testis (CT) antigens, carcinogenesis and spermatogenesis

    PubMed Central

    2011-01-01

    During spermatogenesis, spermatogonial stem cells, undifferentiated and differentiated spermatogonia, spermatocytes, spermatids and spermatozoa all express specific antigens, yet the functions of many of these antigens remain unexplored. Studies in the past three decades have shown that many of these transiently expressed genes in developing germ cells are proto-oncogenes and oncogenes, which are expressed only in the testis and various types of cancers in humans and rodents. As such, these antigens are designated cancer/testis antigens (CT antigens). Since the early 1980s, about 70 families of CT antigens have been identified with over 140 members are known to date. Due to their restricted expression in the testis and in various tumors in humans, they have been used as the target of immunotherapy. Multiple clinical trials at different phases are now being conducted with some promising results. Interestingly, in a significant number of cancer patients, antibodies against some of these CT antigens were detected in their sera. However, antibodies against these CT antigens in humans under normal physiological conditions have yet to be reported even though many of these antigens are residing outside of the blood-testis barrier (BTB), such as in the basal compartment of the seminiferous epithelium and in the stem cell niche in the testis. In this review, we summarize latest findings in the field regarding several selected CT antigens which may be intimately related to spermatogenesis due to their unusual restricted expression during different discrete events of spermatogenesis, such as cell cycle progression, meiosis and spermiogenesis. This information should be helpful to investigators in the field to study the roles of these oncogenes in spermatogenesis. PMID:22319669

  8. DNA Double-Strand Breaks and Telomeres Play Important Roles in Trypanosoma brucei Antigenic Variation

    PubMed Central

    2015-01-01

    Human-infecting microbial pathogens all face a serious problem of elimination by the host immune response. Antigenic variation is an effective immune evasion mechanism where the pathogen regularly switches its major surface antigen. In many cases, the major surface antigen is encoded by genes from the same gene family, and its expression is strictly monoallelic. Among pathogens that undergo antigenic variation, Trypanosoma brucei (a kinetoplastid), which causes human African trypanosomiasis, Plasmodium falciparum (an apicomplexan), which causes malaria, Pneumocystis jirovecii (a fungus), which causes pneumonia, and Borrelia burgdorferi (a bacterium), which causes Lyme disease, also express their major surface antigens from loci next to the telomere. Except for Plasmodium, DNA recombination-mediated gene conversion is a major pathway for surface antigen switching in these pathogens. In the last decade, more sophisticated molecular and genetic tools have been developed in T. brucei, and our knowledge of functions of DNA recombination in antigenic variation has been greatly advanced. VSG is the major surface antigen in T. brucei. In subtelomeric VSG expression sites (ESs), VSG genes invariably are flanked by a long stretch of upstream 70-bp repeats. Recent studies have shown that DNA double-strand breaks (DSBs), particularly those in 70-bp repeats in the active ES, are a natural potent trigger for antigenic variation in T. brucei. In addition, telomere proteins can influence VSG switching by reducing the DSB amount at subtelomeric regions. These findings will be summarized and their implications will be discussed in this review. PMID:25576484

  9. Polyethyleneimine is a potent systemic adjuvant for glycoprotein antigens.

    PubMed

    Sheppard, Neil C; Brinckmann, Sarah A; Gartlan, Kate H; Puthia, Manoj; Svanborg, Catharina; Krashias, George; Eisenbarth, Stephanie C; Flavell, Richard A; Sattentau, Quentin J; Wegmann, Frank

    2014-10-01

    Polyethyleneimine (PEI) is an organic polycation used extensively as a gene and DNA vaccine delivery reagent. Although the DNA targeting activity of PEI is well documented, its immune activating activity is not. We recently reported that PEI has robust mucosal adjuvanticity when administered intranasally with glycoprotein antigens. Here, we show that PEI has strong immune activating activity after systemic delivery. PEI administered subcutaneously with viral glycoprotein (HIV-1 gp140) enhanced antigen-specific serum IgG production in the context of mixed Th1/Th2-type immunity. PEI elicited higher titers of both antigen binding and neutralizing antibodies than alum in mice and rabbits and induced an increased proportion of antibodies reactive with native antigen. In an intraperitoneal model, PEI recruited neutrophils followed by monocytes to the site of administration and enhanced antigen uptake by antigen-presenting cells. The Th bias was modulated by PEI activation of the Nlrp3 inflammasome; however its global adjuvanticity was unchanged in Nlrp3-deficient mice. When coformulated with CpG oligodeoxynucleotides, PEI adjuvant potency was synergistically increased and biased toward a Th1-type immune profile. Taken together, these data support the use of PEI as a versatile systemic adjuvant platform with particular utility for induction of secondary structure-reactive antibodies against glycoprotein antigens. PMID:24844701

  10. 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

  11. Phenotypic H-Antigen Typing by Mass Spectrometry Combined with Genetic Typing of H Antigens, O Antigens, and Toxins by Whole-Genome Sequencing Enhances Identification of Escherichia coli Isolates

    PubMed Central

    Chui, Huixia; Domish, Larissa; Sloan, Angela; Hernandez, Drexler; McCorrister, Stuart; Robinson, Alyssia; Walker, Matthew; Peterson, Lorea A. M.; Majcher, Miles; Ratnam, Sam; Haldane, David J. M.; Bekal, Sadjia; Wylie, John; Chui, Linda; Tyler, Shaun; Xu, Bianli; Reimer, Aleisha; Nadon, Celine; Knox, J. David

    2016-01-01

    Mass spectrometry-based phenotypic H-antigen typing (MS-H) combined with whole-genome-sequencing-based genetic identification of H antigens, O antigens, and toxins (WGS-HOT) was used to type 60 clinical Escherichia coli isolates, 43 of which were previously identified as nonmotile, H type undetermined, or O rough by serotyping or having shown discordant MS-H and serotyping results. Whole-genome sequencing confirmed that MS-H was able to provide more accurate data regarding H antigen expression than serotyping. Further, enhanced and more confident O antigen identification resulted from gene cluster based typing in combination with conventional typing based on the gene pair comprising wzx and wzy and that comprising wzm and wzt. The O antigen was identified in 94.6% of the isolates when the two genetic O typing approaches (gene pair and gene cluster) were used in conjunction, in comparison to 78.6% when the gene pair database was used alone. In addition, 98.2% of the isolates showed the existence of genes for various toxins and/or virulence factors, among which verotoxins (Shiga toxin 1 and/or Shiga toxin 2) were 100% concordant with conventional PCR based testing results. With more applications of mass spectrometry and whole-genome sequencing in clinical microbiology laboratories, this combined phenotypic and genetic typing platform (MS-H plus WGS-HOT) should be ideal for pathogenic E. coli typing. PMID:27307455

  12. Phenotypic H-Antigen Typing by Mass Spectrometry Combined with Genetic Typing of H Antigens, O Antigens, and Toxins by Whole-Genome Sequencing Enhances Identification of Escherichia coli Isolates.

    PubMed

    Cheng, Keding; Chui, Huixia; Domish, Larissa; Sloan, Angela; Hernandez, Drexler; McCorrister, Stuart; Robinson, Alyssia; Walker, Matthew; Peterson, Lorea A M; Majcher, Miles; Ratnam, Sam; Haldane, David J M; Bekal, Sadjia; Wylie, John; Chui, Linda; Tyler, Shaun; Xu, Bianli; Reimer, Aleisha; Nadon, Celine; Knox, J David; Wang, Gehua

    2016-08-01

    Mass spectrometry-based phenotypic H-antigen typing (MS-H) combined with whole-genome-sequencing-based genetic identification of H antigens, O antigens, and toxins (WGS-HOT) was used to type 60 clinical Escherichia coli isolates, 43 of which were previously identified as nonmotile, H type undetermined, or O rough by serotyping or having shown discordant MS-H and serotyping results. Whole-genome sequencing confirmed that MS-H was able to provide more accurate data regarding H antigen expression than serotyping. Further, enhanced and more confident O antigen identification resulted from gene cluster based typing in combination with conventional typing based on the gene pair comprising wzx and wzy and that comprising wzm and wzt The O antigen was identified in 94.6% of the isolates when the two genetic O typing approaches (gene pair and gene cluster) were used in conjunction, in comparison to 78.6% when the gene pair database was used alone. In addition, 98.2% of the isolates showed the existence of genes for various toxins and/or virulence factors, among which verotoxins (Shiga toxin 1 and/or Shiga toxin 2) were 100% concordant with conventional PCR based testing results. With more applications of mass spectrometry and whole-genome sequencing in clinical microbiology laboratories, this combined phenotypic and genetic typing platform (MS-H plus WGS-HOT) should be ideal for pathogenic E. coli typing. PMID:27307455

  13. Virulence of Shigella flexneri Hybrids Expressing Escherichia coli Somatic Antigens

    PubMed Central

    Gemski, P.; Sheahan, D. G.; Washington, O.; Formal, S. B.

    1972-01-01

    The genes controlling either Escherichia coli somatic antigen 8 or 25 were conjugally transferred to virulent Shigella flexneri 2a recipients to determine whether the aquisition of these antigens would affect the virulence of the resulting hybrid. A high proportion of such hybrids were found to be rough and hence were avirulent. Some smooth S. flexneri hybrids which replaced their native group antigens with E. coli factor 25 were still virulent in the animal models employed. All S. flexneri O-8 hybrids were uniformly avirulent. Our finding, that S. flexneri hybrids with the chemically divergent E. coli O-8 repeat unit are avirulent whereas some hybrids with the chemically related O-25 repeat unit retain virulence, suggests that the chemical composition and structure of the O side chain of somatic antigens may represent one determining factor for bacterial penetration of mucosal epithelial cells, the primary step in the pathogenesis of bacillary dysentery. Images PMID:4569915

  14. Human leucocyte antigens in tympanosclerosis.

    PubMed

    Dursun, G; Acar, A; Turgay, M; Calgüner, M

    1997-02-01

    This study was designed to evaluate the association between certain HLA antigens and tympanosclerosis. The serum concentrations of HLA antigens were measured by a microlymphocytotoxicity technique in patients with tympanosclerosis and compared with a healthy control group. The serum levels of HLA-B35 and -DR3 were significantly higher in the patients with tympanosclerosis. This result suggests that certain types of HLA antigens may play an important role as an indicator or mediator in the pathogenesis of tympanosclerosis. PMID:9088683

  15. Expression of Lewis antigenic determinants in colorectal adenocarcinomas.

    PubMed

    Blasco, E; Torrado, J; Cosme, A; Alvarez, E; Zugasti, A; Gutierrez-Hoyos, A; Arenas, J I

    1989-01-01

    Expression of type 1 and type 2 chain Lewis antigens was studied in 32 rectal adenocarcinoma specimens; the results were correlated with the patients' Lewis phenotype and secretor status. In addition, the pattern of expression of these antigens was analyzed in adjacent and distant normal mucosa. We used an indirect immunofluorescence technique with p-phenylenediamine counterstaining (Oriol technique) and a panel of monoclonal antibodies directed against the different antigenic specificities. Normal distal colonic mucosa only expresses monofucosylated structures (Lea and X) arising from activity of the alpha 1-3,4-fucosyltransferase coded by the Le gene. Rectal adenocarcinomas also show Lea and X, but also reexpress blood group antigens ABH and exhibit difucosylated determinants (Leb and Y). The accumulation of mono- and difucosylated type 2 chain in neoplastic processes, independently of the Le and Se genes, could be due to the enzymes coded by reactivation of the H and X genes. Blood group antigens form a complex signal code, genetically regulated, which intervenes in differentiation, growth and cellular recognition processes, and which may undergo important modifications during malignant transformation. These alterations could be useful in the diagnosis and prognosis of some types of carcinoma. PMID:2476347

  16. Novel antigen delivery systems.

    PubMed

    Trovato, Maria; De Berardinis, Piergiuseppe

    2015-08-12

    Vaccines represent the most relevant contribution of immunology to human health. However, despite the remarkable success achieved in the past years, many vaccines are still missing in order to fight important human pathologies and to prevent emerging and re-emerging diseases. For these pathogens the known strategies for making vaccines have been unsuccessful and thus, new avenues should be investigated to overcome the failure of clinical trials and other important issues including safety concerns related to live vaccines or viral vectors, the weak immunogenicity of subunit vaccines and side effects associated with the use of adjuvants. A major hurdle of developing successful and effective vaccines is to design antigen delivery systems in such a way that optimizes antigen presentation and induces broad protective immune responses. Recent advances in vector delivery technologies, immunology, vaccinology and system biology, have led to a deeper understanding of the molecular and cellular mechanisms by which vaccines should stimulate both arms of the adaptive immune responses, offering new strategies of vaccinations. This review is an update of current strategies with respect to live attenuated and inactivated vaccines, DNA vaccines, viral vectors, lipid-based carrier systems such as liposomes and virosomes as well as polymeric nanoparticle vaccines and virus-like particles. In addition, this article will describe our work on a versatile and immunogenic delivery system which we have studied in the past decade and which is derived from a non-pathogenic prokaryotic organism: the "E2 scaffold" of the pyruvate dehydrogenase complex from Geobacillus stearothermophilus. PMID:26279977

  17. Stool Test: H. Pylori Antigen

    MedlinePlus

    ... Things to Know About Zika & Pregnancy Stool Test: H. Pylori Antigen KidsHealth > For Parents > Stool Test: H. Pylori Antigen Print A A A Text Size ... en español Muestra de materia fecal: antígeno de H. pylori What It Is Helicobacter pylori ( H. pylori ) ...

  18. 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

  19. Novel antigen delivery systems

    PubMed Central

    Trovato, Maria; Berardinis, Piergiuseppe De

    2015-01-01

    Vaccines represent the most relevant contribution of immunology to human health. However, despite the remarkable success achieved in the past years, many vaccines are still missing in order to fight important human pathologies and to prevent emerging and re-emerging diseases. For these pathogens the known strategies for making vaccines have been unsuccessful and thus, new avenues should be investigated to overcome the failure of clinical trials and other important issues including safety concerns related to live vaccines or viral vectors, the weak immunogenicity of subunit vaccines and side effects associated with the use of adjuvants. A major hurdle of developing successful and effective vaccines is to design antigen delivery systems in such a way that optimizes antigen presentation and induces broad protective immune responses. Recent advances in vector delivery technologies, immunology, vaccinology and system biology, have led to a deeper understanding of the molecular and cellular mechanisms by which vaccines should stimulate both arms of the adaptive immune responses, offering new strategies of vaccinations. This review is an update of current strategies with respect to live attenuated and inactivated vaccines, DNA vaccines, viral vectors, lipid-based carrier systems such as liposomes and virosomes as well as polymeric nanoparticle vaccines and virus-like particles. In addition, this article will describe our work on a versatile and immunogenic delivery system which we have studied in the past decade and which is derived from a non-pathogenic prokaryotic organism: the “E2 scaffold” of the pyruvate dehydrogenase complex from Geobacillus stearothermophilus. PMID:26279977

  20. Radioimmunoassays of hidden viral antigens

    SciTech Connect

    Neurath, A.R.; Strick, N.; Baker, L.; Krugman, S.

    1982-07-01

    Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis B virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure.

  1. Genetics and Evolution of the Salmonella Galactose-Initiated Set of O Antigens

    PubMed Central

    Reeves, Peter R.; Cunneen, Monica M.; Liu, Bin; Wang, Lei

    2013-01-01

    This paper covers eight Salmonella serogroups, that are defined by O antigens with related structures and gene clusters. They include the serovars that are now most frequently isolated. Serogroups A, B1, B2, C2-C3, D1, D2, D3 and E have O antigens that are distinguished by having galactose as first sugar, and not N-acetyl glucosamine or N-acetyl galactosamine as in the other 38 serogroups, and indeed in most Enterobacteriaceae. The gene clusters for these galactose-initiated appear to have entered S. enterica since its divergence from E. coli, but sequence comparisons show that much of the diversification occurred long before this. We conclude that the gene clusters must have entered S. enterica in a series of parallel events. The individual gene clusters are discussed, followed by analysis of the divergence for those genes shared by two or more gene clusters, and a putative phylogenic tree for the gene clusters is presented. This set of O antigens provides a rare case where it is possible to examine in detail the relationships of a significant number of O antigens. In contrast the more common pattern of O-antigen diversity within a species is for there to be only a few cases of strains having related gene clusters, suggesting that diversity arose through gain of individual O-antigen gene clusters by lateral gene transfer, and under these circumstances the evolution of the diversity is not accessible. This paper on the galactose-initiated set of gene clusters gives new insights into the origins of O-antigen diversity generally. PMID:23874940

  2. Antigenic and molecular characterization of rabies virus in Argentina.

    PubMed

    Cisterna, Daniel; Bonaventura, Romina; Caillou, Susana; Pozo, Oscar; Andreau, Maria Lidia; Fontana, Liliana Dalla; Echegoyen, Cristina; de Mattos, Carlos; de Mattos, Cecilia; Russo, Susana; Novaro, Laura; Elberger, Diana; Freire, María Cecilia

    2005-05-01

    The nucleoprotein genes of 54 human, domestic and wild animals rabies isolates obtained in Argentina between 1995 and 2002 were characterized using monoclonal antibodies and partial gene sequence analysis. The antigenic and genetic diversities of rabies virus in samples from bat and bat-related cases were studied, leading to the identification of five distinct genetic variants. Rabies viruses isolated from vampire bat related cases were very similar to each other, showing 98.9% overall similarity. Specific antigenic variants (AgV) were detected associated with different insectivorous bats species, in samples from Tadarida brasiliensis and Eumops patagonicus bats. In contrast, isolates from Myotis sp. and Histiotus sp. bats could not be matched to any antigenic type. Additionally, bat rabies cases were also detected in southern provinces previously considered rabies-free. Finally, two independent antigenic and genetic variants co-circulating in northern Argentina were found in isolates obtained from dogs and dog-related cases, suggesting two independent cycles of virus transmission. This is the first national coordinated study of antigenic as well as molecular epidemiology of rabies in Argentina. The information presented here will improve our knowledge about rabies epidemiology and therefore, will assist preventing fatal human cases. PMID:15763144

  3. Identification of the class I genes of the mouse major histocompatibility complex by DNA-mediated gene transfer.

    PubMed

    Goodenow, R S; McMillan, M; Nicolson, M; Sher, B T; Eakle, K; Davidson, N; Hood, L

    1982-11-18

    DNA-mediated gene transfer was used to identify cloned class I genes from the major histocompatibility complex of the BALB/c mouse. Three genes encoding the transplantation antigens H-2 Kd, Dd and Ld were identified as well as genes encoding the Qa-2,3 and two TL differentiation antigens. As many as 10 putative novel class I genes were detected by the association of their gene products with beta 2-microglobulin. Alloantiserum prepared to one of the novel antigens was used to demonstrate the expression of the previously undetected antigen on spleen cells of various inbred, congeneic, and recombinant congeneic strains of mice. PMID:6815535

  4. [Antigenic response against PPD and antigen 60 in tubercular patients: single antigen versus the combined test].

    PubMed

    Máttar, S; Broquetas, J M; Gea, J; Aran, X; el-Banna, N; Sauleda, J; Torres, J M

    1992-05-01

    We analyze serum samples from 70 patients with pulmonary tuberculosis and 50 healthy individuals. The antigenic activity (IgG) against protein purified antigen (PPD) and antigen 60 (A60) from M. tuberculosis. Thirteen patients were also HIV infected, and three patients had AIDS defined by the presence of disseminated tuberculosis. The test using antigen alone showed a 77% sensitivity and 74% specificity when PPD is used. When A60 was used, both values improved (81% sensitivity, 94% specificity). The use of a combined test (PPD and A60) improves the sensitivity (89%) but reduces the specificity (82%). The HIV infected patients showed similar responses to those of other patients. The combined use of different antigens might be useful for diagnosing tuberculosis. PMID:1390996

  5. Altering the antigenicity of proteins.

    PubMed Central

    Alexander, H; Alexander, S; Getzoff, E D; Tainer, J A; Geysen, H M; Lerner, R A

    1992-01-01

    To better understand the binding interaction between antigen and antibody we need to distinguish protein residues critical to the binding energy and mechanism from residues merely localized in the interface. By analyzing the binding of monoclonal antibodies to recombinant wild-type and mutant myohemerythrin (MHr) proteins, we were able to test the role of individual critical residues at the highly antigenic site MHr-(79-84), within the context of the folded protein. The results directly show the existence of antigenically critical residues, whose mutations significantly reduce antibody binding to the folded protein, thus verifying peptide-based assignments of these critical residues and demonstrating the ability of buried side chains to influence antigenicity. Taken together, these results (i) distinguish the antigenic surface from the solvent-exposed protein surface before binding, (ii) support a two-stage interaction mechanism allowing inducible changes in protein antigens by antibody binding, and (iii) show that protein antigenicity can be significantly reduced by alteration of single critical residues without destroying biological activity. Images PMID:1373498

  6. Antigen Retrieval Immunohistochemistry

    PubMed Central

    Shi, Shan-Rong; Shi, Yan; Taylor, Clive R.

    2011-01-01

    As a review for the 20th anniversary of publishing the antigen retrieval (AR) technique in this journal, the authors intend briefly to summarize developments in AR-immunohistochemistry (IHC)–based research and diagnostics, with particular emphasis on current challenges and future research directions. Over the past 20 years, the efforts of many different investigators have coalesced in extending the AR approach to all areas of anatomic pathology diagnosis and research and further have led to AR-based protein extraction techniques and tissue-based proteomics. As a result, formalin-fixed paraffin-embedded (FFPE) archival tissue collections are now seen as a literal treasure of materials for clinical and translational research to an extent unimaginable just two decades ago. Further research in AR-IHC is likely to focus on tissue proteomics, developing a more efficient protocol for protein extraction from FFPE tissue based on the AR principle, and combining the proteomics approach with AR-IHC to establish a practical, sophisticated platform for identifying and using biomarkers in personalized medicine. PMID:21339172

  7. Potentially conflicting selective forces that shape the vls antigenic variation system in Borrelia burgdorferi

    PubMed Central

    Zhou, Wei; Brisson, Dustin

    2014-01-01

    Changing environmental conditions present an evolutionary challenge for all organisms. The environment of microbial pathogens, including the adaptive immune responses of the infected host, changes rapidly and is lethal to the pathogen lineages that cannot quickly adapt. The dynamic immune environment creates strong selective pressures favoring microbial pathogen lineages with antigenic variation systems that maximize the antigenic divergence among expressed antigenic variants. However, divergence among expressed antigens may be constrained by other molecular features such as the efficient expression of functional proteins. We computationally examined potential conflicting selection pressures on antigenic variation systems using the vls antigenic variation system in Borrelia burgdorferi as a model system. The vls system alters the sequence of the expressed antigen by recombining gene fragments from unexpressed but divergent ‘cassettes’ into the expression site, vlsE. The in silico analysis of natural and altered cassettes from seven lineages in the B. burgdorferi sensu lato species complex revealed that sites that are polymorphic among unexpressed cassettes, as well as the insertion/deletion mutations, are organized to maximize divergence among the expressed antigens within the constraints of translational ability and high translational efficiency. This study provides empirical evidence that conflicting selection pressures on antigenic variation systems can limit the potential antigenic divergence in order to maintain proper molecular function. PMID:24837669

  8. Rearrangements of T-cell antigen receptor gamma and delta chain genes are detected in the long-term cultured bone marrow cells of athymic nude mice but not in those of euthymic mice.

    PubMed Central

    Yoshikai, Y; Takeda, Y; Ohga, S; Kishihara, K; Matsuzaki, G; Nomoto, K

    1989-01-01

    We have previously shown that extrathymic rearrangements of T-cell receptor (TcR) gamma and delta chain genes occur in the peripheral lymphoid tissues of athymic nude mice. To further determine where the TcR gene rearrangements occur in nude mice, we investigated the rearrangement and expression of the TcR genes in the long-term cultured bone marrow (LTBM) cells which were homogenous in developments without mature T cells as assessed by FACS analysis. The LTBM derived from euthymic mice contained TcR gamma and delta chain genes in germline configuration, while gene rearrangements of both locus were detected in the LTBM cells from nude mice. These results suggested that gamma and delta gene rearrangements do occur in the bone marrow cells of nude mice and that the T-cell precursors in bone marrow may be increased in frequency in such animals. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2541071

  9. Comparative Analysis of Gingival Tissue Antigen Presentation Pathways in Aging and Periodontitis

    PubMed Central

    Gonzalez, O.A.; Novak, M.J.; Kirakodu, S.; Orraca, L.; Chen, K.C.; Strom-berg, A.; Gonzalez-Martinez, J.; Ebersole, J. L.

    2014-01-01

    Aim Gingival tissues of periodontitis lesions contribute to local elevations in mediators, including both specific T cell and antibody immune responses to oral bacterial antigens. Thus, antigen processing and presentation activities must exist in these tissues to link antigen-presenting cells with adaptive immunity. We hypothesized that alterations in the transcriptome of antigen processing and presentation genes occur in aging gingival tissues and that periodontitis enhances these differences reflecting tissues less capable of immune resistance to oral pathogens. Materials and Methods Rhesus monkeys (n=34) from 3–23 years of age were examined. A buccal gingival sample from healthy or periodontitis sites were obtained, total RNA isolated, and microarray analysis was used to describe the transcriptome. Results The results demonstrated increased transcription of genes related to the MHC class II and negative regulation of NK cells with aging in healthy gingival tissues. In contrast, both adult and aging periodontitis tissues showed decreased transcription of genes for MHC class II antigens, coincident with up-regulation of MHC class I-associated genes. Conclusion These transcriptional changes suggest a response of healthy aging tissues through the class II pathway (i.e., endocytosed antigens) and altered responses in periodontitis that could reflect host-associated self-antigens or targeting cytosolic intra-cellular microbial pathogens. PMID:24304139

  10. Serological identification of Tektin5 as a cancer/testis antigen and its immunogenicity

    PubMed Central

    2012-01-01

    Background Identification of new cancer antigens is necessary for the efficient diagnosis and immunotherapy. A variety of tumor antigens have been identified by several methodologies. Among those antigens, cancer/testis (CT) antigens have became promising targets. Methods The serological identification of antigens by the recombinant expression cloning (SEREX) methodology has been successfully used for the identification of cancer/testis (CT) antigens. We performed the SEREX analysis of colon cancer. Results We isolated a total of 60 positive cDNA clones comprising 38 different genes. They included 2 genes with testis-specific expression profiles in the UniGene database, such as TEKT5 and a CT-like gene, A kinase anchoring protein 3 (AKAP3). Quantitative real-time RT-PCR analysis showed that the expression of TEKT5 was restricted to the testis in normal adult tissues. In malignant tissues, TEKT5 was aberrantly expressed in a variety of cancers, including colon cancer. A serological survey of 101 cancer patients with different cancers by ELISA revealed antibodies to TEKT5 in 13 patients, including colon cancer. None of the 16 healthy donor serum samples were reactive in the same test. Conclusion We identified candidate new CT antigen of colon cancer, TEKT5. The findings indicate that TEKT5 is immunogenic in humans, and suggest its potential use as diagnostic as well as an immunotherapeutic reagent for cancer patients. PMID:23151147

  11. Natural Selection Promotes Antigenic Evolvability

    PubMed Central

    Graves, Christopher J.; Ros, Vera I. D.; Stevenson, Brian; Sniegowski, Paul D.; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed ‘cassettes’ that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections

  12. Aptamer-targeted Antigen Delivery

    PubMed Central

    Wengerter, Brian C; Katakowski, Joseph A; Rosenberg, Jacob M; Park, Chae Gyu; Almo, Steven C; Palliser, Deborah; Levy, Matthew

    2014-01-01

    Effective therapeutic vaccines often require activation of T cell-mediated immunity. Robust T cell activation, including CD8 T cell responses, can be achieved using antibodies or antibody fragments to direct antigens of interest to professional antigen presenting cells. This approach represents an important advance in enhancing vaccine efficacy. Nucleic acid aptamers present a promising alternative to protein-based targeting approaches. We have selected aptamers that specifically bind the murine receptor, DEC205, a C-type lectin expressed predominantly on the surface of CD8α+ dendritic cells (DCs) that has been shown to be efficient at facilitating antigen crosspresentation and subsequent CD8+ T cell activation. Using a minimized aptamer conjugated to the model antigen ovalbumin (OVA), DEC205-targeted antigen crosspresentation was verified in vitro and in vivo by proliferation and cytokine production by primary murine CD8+ T cells expressing a T cell receptor specific for the major histocompatibility complex (MHC) I-restricted OVA257–264 peptide SIINFEKL. Compared with a nonspecific ribonucleic acid (RNA) of similar length, DEC205 aptamer-OVA-mediated antigen delivery stimulated strong proliferation and production of interferon (IFN)-γ and interleukin (IL)-2. The immune responses elicited by aptamer-OVA conjugates were sufficient to inhibit the growth of established OVA-expressing B16 tumor cells. Our results demonstrate a new application of aptamer technology for the development of effective T cell-mediated vaccines. PMID:24682172

  13. Detection of Burkholderia pseudomallei O-antigen serotypes in near-neighbor species

    PubMed Central

    2012-01-01

    Background Burkholderia pseudomallei is the etiological agent of melioidosis and a CDC category B select agent with no available effective vaccine. Previous immunizations in mice have utilized the lipopolysaccharide (LPS) as a potential vaccine target because it is known as one of the most important antigenic epitopes in B. pseudomallei. Complicating this strategy are the four different B. pseudomallei LPS O-antigen types: A, B, B2, and rough. Sero-crossreactivity is common among O-antigens of Burkholderia species. Here, we identified the presence of multiple B. pseudomallei O-antigen types and sero-crossreactivity in its near-neighbor species. Results PCR screening of O-antigen biosynthesis genes, phenotypic characterization using SDS-PAGE, and immunoblot analysis showed that majority of B. mallei and B. thailandensis strains contained the typical O-antigen type A. In contrast, most of B. ubonensis and B. thailandensis-like strains expressed the atypical O-antigen types B and B2, respectively. Most B. oklahomensis strains expressed a distinct and non-seroreactive O-antigen type, except strain E0147 which expressed O-antigen type A. O-antigen type B2 was also detected in B. thailandensis 82172, B. ubonensis MSMB108, and Burkholderia sp. MSMB175. Interestingly, B. thailandensis-like MSMB43 contained a novel serotype B positive O-antigen. Conclusions This study expands the number of species which express B. pseudomallei O-antigen types. Further work is required to elucidate the full structures and how closely these are to the B. pseudomallei O-antigens, which will ultimately determine the efficacy of the near-neighbor B serotypes for vaccine development. PMID:23126230

  14. Tumor antigens as proteogenomic biomarkers in invasive ductal carcinomas

    PubMed Central

    2014-01-01

    Background The majority of genetic biomarkers for human cancers are defined by statistical screening of high-throughput genomics data. While a large number of genetic biomarkers have been proposed for diagnostic and prognostic applications, only a small number have been applied in the clinic. Similarly, the use of proteomics methods for the discovery of cancer biomarkers is increasing. The emerging field of proteogenomics seeks to enrich the value of genomics and proteomics approaches by studying the intersection of genomics and proteomics data. This task is challenging due to the complex nature of transcriptional and translation regulatory mechanisms and the disparities between genomic and proteomic data from the same samples. In this study, we have examined tumor antigens as potential biomarkers for breast cancer using genomics and proteomics data from previously reported laser capture microdissected ER+ tumor samples. Results We applied proteogenomic analyses to study the genetic aberrations of 32 tumor antigens determined in the proteomic data. We found that tumor antigens that are aberrantly expressed at the genetic level and expressed at the protein level, are likely involved in perturbing pathways directly linked to the hallmarks of cancer. The results found by proteogenomic analysis of the 32 tumor antigens studied here, capture largely the same pathway irregularities as those elucidated from large-scale screening of genomics analyses, where several thousands of genes are often found to be perturbed. Conclusion Tumor antigens are a group of proteins recognized by the cells of the immune system. Specifically, they are recognized in tumor cells where they are present in larger than usual amounts, or are physiochemically altered to a degree at which they no longer resemble native human proteins. This proteogenomic analysis of 32 tumor antigens suggests that tumor antigens have the potential to be highly specific biomarkers for different cancers. PMID:25521819

  15. 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

  16. Chimeric Antigen Receptor (CAR)-Engineered Lymphocytes for Cancer Therapy

    PubMed Central

    Ramos, Carlos A.; Dotti, Gianpietro

    2011-01-01

    Introduction Chimeric antigen receptors (CARs) usually combine the antigen binding site of a monoclonal antibody with the signal activating machinery of a T cell, freeing antigen recognition from major histocompatibility complex restriction and thus breaking one of the barriers to more widespread application of cellular therapy. Similar to treatment strategies employing monoclonal antibodies, T cells expressing CARs are highly targeted, but additionally offer the potential benefits of active trafficking to tumor sites, in vivo expansion and long term persistence. Furthermore, gene transfer allows the introduction of countermeasures to tumor immune evasion and of safety mechanisms. Areas covered The authors review the basic structure of so-called first and later generation CARs and their potential advantages over other immune therapy systems. It is described how these molecules can be grafted into immune cells (including retroviral and non-retroviral transduction methods) and strategies to improve the in vivo persistence and function of immune cells expressing CARs are discussed. Examples of tumor associated antigens that have been targeted in preclinical models are presented and clinical experience with these modified cells is summarized. Finally, a discussion on safety issues surrounding CAR gene transfer into T cells and potential solutions to them, are presented. Expert opinion Because of recent advances in immunology, genetics and cell processing, CAR-modified T cells will likely play an increasing role in the cellular therapy of cancer, chronic infections and autoimmune disorders. PMID:21463133

  17. Identification of Enterococcus faecalis antigens specifically expressed in vivo

    PubMed Central

    Shet, Uttom K.; Park, Sang-Won; Lim, Hyun-Pil; Yun, Kwi-Dug; Kang, Seong Soo; Kim, Se Eun

    2015-01-01

    Objectives Molecular mechanism of the pathogenicity of Enterococcus faecalis (E. faecalis), a suspected endodontic pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here we report the identification of in vivo expressed antigens of E. faecalis by using a novel immunoscreening technique called change-mediated antigen technology (CMAT) and an experimental animal model of endodontic infection. Materials and Methods Among 4,500 E. coli recombinant clones screened, 19 positive clones reacted reproducibly with hyperimmune sera obtained from rabbits immunized with E. faecalis cells isolated from an experimental endodontic infection. DNA sequences from 16 of these in vivo-induced (IVI) genes were determined. Results Identified protein antigens of E. faecalis included enzymes involved in housekeeping functions, copper resistance protein, putative outer membrane proteins, and proteins of unknown function. Conclusions In vivo expressed antigens of E. faecalis could be identified by using a novel immune-screening technique CMAT and an experimental animal model of endodontic infection. Detailed analysis of these IVI genes will lead to a better understanding of the molecular mechanisms involved in the endodontic infection of E. faecalis. PMID:26587417

  18. Cloning and characterization of T-cell-reactive protein antigens from Listeria monocytogenes.

    PubMed Central

    Beattie, I A; Swaminathan, B; Ziegler, H K

    1990-01-01

    To explore the molecular basis of the T-cell-mediated immune response to Listeria monocytogenes, we cloned and expressed listerial antigens in Escherichia coli using the lambda-ZAP bacteriophage and Bluescript plasmid vectors. A two-stage screening strategy was implemented to identify T-cell-reactive antigens; the first stage involved antibodies or oligonucleotide probes and the second stage was based on assays for T-cell activation. A library of genomic DNA from L. monocytogenes was generated in lambda-ZAP, and then antigens, were detected in infected cells with a polyclonal rabbit anti-L. monocytogenes antiserum and an L. monocytogenes-specific monoclonal antibody. Also, synthetic oligonucleotide probes corresponding to the structural gene for listeriolysin O (LLO) were used to screen the recombinant DNA library. In each case, positive isolates were evaluated for T-cell antigenicity by measuring antigen-induced interleukin-2 production by polyclonal T cells taken from L. monocytogenes-immune mice. Phage clones were subcloned and expressed in the Bluescript plasmid and tested further for antigenic activity and LLO expression. Using this screening strategy, we successfully identified bacterial clones producing recombinant listerial antigens which activate L. monocytogenes-immune T cells in vitro. Antigens operative in the T-cell response during infection with L. monocytogenes include LLO, 62- and 39-kilodalton proteins, and other poorly defined bacterial surface components. We also found that high concentrations of recombinant LLO inhibited macrophage-mediated antigen presentation. These results are discussed in terms of the multiple functions of LLO as a virulence factor, inhibitor of antigen presentation, and potent antigen in the T-cell response to L. monocytogenes. These studies represent the first step toward a genetic definition of the antigens recognized in immune defense to L. monocytogenes. Images PMID:2117570

  19. [Detection and typing for swine leukocyte antigen].

    PubMed

    Li, Hua; Luo, Huai-Rong; Zhang, Ya-Ping; Qiu, Xiang-Pin; Ye, Chun

    2004-03-01

    Traditionally the cluster of swine leukocyte antigen (SLA) was typed by serological, cytological and biochemical methods. Many special molecular typing methods have been developed with the progress of molecular biological technology, such as PCR-RFLP, PCR-SSCP , MS and DNA sequencing. Here we discussed the advantages and disadvantages of each method based on the polymorphic and conservative (from the functional aspect, such as supertype and supermotif) characteristics of SLA, and illustrated the development of typing for SLA in the future. In addition, we pointed out the editorial mistakes about the serological haplotype of SLA in reference book and emphasized that the accurate polymorphism of SLA-DQB gene must be based on the cloning sequencing. PMID:15639990

  20. Surface antigens of smooth brucellae.

    PubMed

    Diaz, R; Jones, L M; Leong, D; Wilson, J B

    1968-10-01

    Surface antigens of smooth brucellae were extracted by ether-water, phenol-water, trichloroacetic acid, and saline and examined by immunoelectrophoresis and gel diffusion with antisera from infected and immunized rabbits. Ether-water extracts of Brucella melitensis contained a lipopolysaccharide protein component, which was specific for the surface of smooth brucellae and was correlated with the M agglutinogen of Wilson and Miles, a polysaccharide protein component devoid of lipid which was not restricted to the surface of smooth brucellae and was not correlated with the smooth agglutinogen (component 1), and several protein components which were associated with internal antigens of rough and smooth brucellae. Immunoelectrophoretic analysis of ether-water extracts of B. abortus revealed only two components, a lipopolysaccharide protein component, which was correlated with the A agglutinogen, and component 1. Component 1 from B. melitensis and B. abortus showed identity in gel diffusion tests, whereas component M from B. melitensis and component A from B. abortus showed partial identity with unabsorbed antisera and no cross-reactions with monospecific sera. Attempts to prepare monospecific sera directly by immunization of rabbits with cell walls or ether-water extracts were unsuccessful. Absorption of antisera with heavy fraction of ether-water extracts did not always result in monospecific sera. It was concluded (as has been described before) that the A and M antigens are present on a single antigenic complex, in different proportions depending upon the species and biotype, and that this component is a lipopolysaccharide protein complex of high molecular weight that diffuses poorly through agar gel. Components 1, A, and M were also demonstrated in trichloroacetic acid and phenol-water extracts. With all extracts, B. melitensis antigen showed greater diffusibility in agar than B. abortus antigens. After mild acid hydrolysis, B. abortus ether-water extract was able

  1. Characterisation of Sarcoptes scabiei antigens.

    PubMed

    Hejduk, Gloria; Hofstätter, Katja; Löwenstein, Michael; Peschke, Roman; Miller, Ingrid; Joachim, Anja

    2011-02-01

    In pig herds, the status of Sarcoptes scabiei infections is routinely monitored by serodiagnosis. Crude antigen for ELISA is usually prepared from S. scabiei var. canis or other variations and may lead to variations in the outcome of different tests, making assay standardisation difficult. This study was performed to investigate the antigen profiles of S. scabiei, including differences between hydrophilic and more hydrophobic protein fractions, by Western blotting with sera from pigs with defined infection status. Potential cross-reactivity among S. scabiei (var. canis, suis and bovis), Dermatophagoides farinae and Tyrophagus putrescentiae was also analysed. Hydrophobic S. scabiei antigens were detectable in the range of 40-50 kDa, whilst the hydrophilic fraction showed no specific antigenicity. In the hydrophobic fractions of D. farinae and T. putrescentiae, two major protein fractions in a similar size range could be identified, but no cross-reactivity with Sarcoptes-positive sera was detectable. However, examination of the hydrophilic fractions revealed cross-reactivity between Sarcoptes-positive sera and both the house dust mite and the storage mite in the range of 115 and 28/38 kDa. Specific bands in the same range (42 and 48 kDa) could be detected in blots from hydrophobic fractions of all three tested variations of S. scabiei (var. canis, bovis and suis). These results show that there are considerable differences in mange antibody reactivity, including reactions with proteins from free-living mites, which may interfere with tests based on hydrophilic antigens. Further refinement of antigen and the use of specific hydrophobic proteins could improve ELISA performance and standardisation. PMID:20865427

  2. Adoptive therapy with redirected primary regulatory T cells results in antigen-specific suppression of arthritis.

    PubMed

    Wright, Graham P; Notley, Clare A; Xue, Shao-An; Bendle, Gavin M; Holler, Angelika; Schumacher, Ton N; Ehrenstein, Michael R; Stauss, Hans J

    2009-11-10

    Regulatory T cells (Tregs) can suppress a wide range of immune cells, making them an ideal candidate for the treatment of autoimmunity. The potential clinical translation of targeted therapy with antigen-specific Tregs is hampered by the difficulties of isolating rare specificities from the natural polyclonal T cell repertoire. Moreover, the initiating antigen is often unknown in autoimmune disease. Here we tested the ability of antigen-specific Tregs generated by retroviral gene transfer to ameliorate arthritis through linked suppression and therefore without cognate recognition of the disease-initiating antigen. We explored two distinct strategies: T cell receptor (TCR) gene transfer into purified CD4+CD25+ T cells was used to redirect the specificity of naturally occurring Tregs; and co-transfer of FoxP3 and TCR genes served to convert conventional CD4(+) T cells into antigen-specific regulators. Following adoptive transfer into recipient mice, the gene-modified T cells engrafted efficiently and retained TCR and FoxP3 expression. Using an established arthritis model, we demonstrate antigen-driven accumulation of the gene modified T cells at the site of joint inflammation, which resulted in a local reduction in the number of inflammatory Th17 cells and a significant decrease in arthritic bone destruction. Together, we describe a robust strategy to rapidly generate antigen-specific regulatory T cells capable of highly targeted inhibition of tissue damage in the absence of systemic immune suppression. This opens the possibility to target Tregs to tissue-specific antigens for the treatment of autoimmune tissue damage without the knowledge of the disease-causing autoantigens recognized by pathogenic T cells. PMID:19884493

  3. Identification of Novel Pre-Erythrocytic Malaria Antigen Candidates for Combination Vaccines with Circumsporozoite Protein

    PubMed Central

    Sahu, Tejram; Malkov, Vlad; Morrison, Robert; Pei, Ying; Juompan, Laure; Milman, Neta; Zarling, Stasya; Anderson, Charles; Wong-Madden, Sharon; Wendler, Jason; Ishizuka, Andrew; MacMillen, Zachary W.; Garcia, Valentino; Kappe, Stefan H. I.; Krzych, Urszula; Duffy, Patrick E.

    2016-01-01

    Malaria vaccine development has been hampered by the limited availability of antigens identified through conventional discovery approaches, and improvements are needed to enhance the efficacy of the leading vaccine candidate RTS,S that targets the circumsporozoite protein (CSP) of the infective sporozoite. Here we report a transcriptome-based approach to identify novel pre-erythrocytic vaccine antigens that could potentially be used in combination with CSP. We hypothesized that stage-specific upregulated genes would enrich for protective vaccine targets, and used tiling microarray to identify P. falciparum genes transcribed at higher levels during liver stage versus sporozoite or blood stages of development. We prepared DNA vaccines for 21 genes using the predicted orthologues in P. yoelii and P. berghei and tested their efficacy using different delivery methods against pre-erythrocytic malaria in rodent models. In our primary screen using P. yoelii in BALB/c mice, we found that 16 antigens significantly reduced liver stage parasite burden. In our confirmatory screen using P. berghei in C57Bl/6 mice, we confirmed 6 antigens that were protective in both models. Two antigens, when combined with CSP, provided significantly greater protection than CSP alone in both models. Based on the observations reported here, transcriptional patterns of Plasmodium genes can be useful in identifying novel pre-erythrocytic antigens that induce protective immunity alone or in combination with CSP. PMID:27434123

  4. [Farmer's lung antigens in Germany].

    PubMed

    Sennekamp, J; Joest, M; Sander, I; Engelhart, S; Raulf-Heimsoth, M

    2012-05-01

    Recent studies suggest that besides the long-known farmer's lung antigen sources Saccharopolyspora rectivirgula (Micropolyspora faeni), Thermoactinomyces vulgaris, and Aspergillus fumigatus, additionally the mold Absidia (Lichtheimia) corymbifera as well as the bacteria Erwinia herbicola (Pantoea agglomerans) and Streptomyces albus may cause farmer's lung in Germany. In this study the sera of 64 farmers with a suspicion of farmer's lung were examined for the following further antigens: Wallemia sebi, Cladosporium herbarum, Aspergillus versicolor, and Eurotium amstelodami. Our results indicate that these molds are not frequent causes of farmer's lung in Germany. PMID:22477566

  5. Integrative Discovery of Epigenetically Derepressed Cancer Testis Antigens in NSCLC

    PubMed Central

    Glazer, Chad A.; Smith, Ian M.; Ochs, Michael F.; Begum, Shahnaz; Westra, William; Chang, Steven S.; Sun, Wenyue; Bhan, Sheetal; Khan, Zubair; Ahrendt, Steven; Califano, Joseph A.

    2009-01-01

    Background Cancer/testis antigens (CTAs) were first discovered as immunogenic targets normally expressed in germline cells, but differentially expressed in a variety of human cancers. In this study, we used an integrative epigenetic screening approach to identify coordinately expressed genes in human non-small cell lung cancer (NSCLC) whose transcription is driven by promoter demethylation. Methodology/Principal Findings Our screening approach found 290 significant genes from the over 47,000 transcripts incorporated in the Affymetrix Human Genome U133 Plus 2.0 expression array. Of the top 55 candidates, 10 showed both differential overexpression and promoter region hypomethylation in NSCLC. Surprisingly, 6 of the 10 genes discovered by this approach were CTAs. Using a separate cohort of primary tumor and normal tissue, we validated NSCLC promoter hypomethylation and increased expression by quantitative RT-PCR for all 10 genes. We noted significant, coordinated coexpression of multiple target genes, as well as coordinated promoter demethylation, in a large set of individual tumors that was associated with the SCC subtype of NSCLC. In addition, we identified 2 novel target genes that exhibited growth-promoting effects in multiple cell lines. Conclusions/Significance Coordinated promoter demethylation in NSCLC is associated with aberrant expression of CTAs and potential, novel candidate protooncogenes that can be identified using integrative discovery techniques. These findings have significant implications for discovery of novel CTAs and CT antigen directed immunotherapy. PMID:19997593

  6. Antibody repertoire deep sequencing reveals antigen-independent selection in maturing B cells

    PubMed Central

    Kaplinsky, Joseph; Li, Anthony; Sun, Amy; Coffre, Maryaline; Koralov, Sergei B.; Arnaout, Ramy

    2014-01-01

    Antibody repertoires are known to be shaped by selection for antigen binding. Unexpectedly, we now show that selection also acts on a non–antigen-binding antibody region: the heavy-chain variable (VH)–encoded “elbow” between variable and constant domains. By sequencing 2.8 million recombined heavy-chain genes from immature and mature B-cell subsets in mice, we demonstrate a striking gradient in VH gene use as pre-B cells mature into follicular and then into marginal zone B cells. Cells whose antibodies use VH genes that encode a more flexible elbow are more likely to mature. This effect is distinct from, and exceeds in magnitude, previously described maturation-associated changes in heavy-chain complementarity determining region 3, a key antigen-binding region, which arise from junctional diversity rather than differential VH gene use. Thus, deep sequencing reveals a previously unidentified mode of B-cell selection. PMID:24927543

  7. New Data on Vaccine Antigen Deficient Bordetella pertussis Isolates

    PubMed Central

    Bouchez, Valérie; Hegerle, Nicolas; Strati, Francesco; Njamkepo, Elisabeth; Guiso, Nicole

    2015-01-01

    Evolution of Bordetella pertussis is driven by natural and vaccine pressures. Isolates circulating in regions with high vaccination coverage present multiple allelic and antigenic variations as compared to isolates collected before introduction of vaccination. Furthermore, during the last epidemics reported in regions using pertussis acellular vaccines, isolates deficient for vaccine antigens, such as pertactin (PRN), were reported to reach high proportions of circulating isolates. More sporadic filamentous hemagglutinin (FHA) or pertussis toxin (PT) deficient isolates were also collected. The whole genome of some recent French isolates, deficient or non-deficient in vaccine antigens, were analyzed. Transcription profiles of the expression of the main virulence factors were also compared. The invasive phenotype in an in vitro human tracheal epithelial (HTE) cell model of infection was evaluated. Our genomic analysis focused on SNPs related to virulence genes known to be more likely to present allelic polymorphism. Transcriptomic data indicated that isolates circulating since the introduction of pertussis vaccines present lower transcription levels of the main virulence genes than the isolates of the pre-vaccine era. Furthermore, isolates not producing FHA present significantly higher expression levels of the entire set of genes tested. Finally, we observed that recent isolates are more invasive in HTE cells when compared to the reference strain, but no multiplication occurs within cells. PMID:26389958

  8. Proteolysis, proteasomes and antigen presentation

    NASA Technical Reports Server (NTRS)

    Goldberg, A. L.; Rock, K. L.

    1992-01-01

    Proteins presented to the immune system must first be cleaved to small peptides by intracellular proteinases. Proteasomes are proteolytic complexes that degrade cytosolic and nuclear proteins. These particles have been implicated in ATP-ubiquitin-dependent proteolysis and in the processing of intracellular antigens for cytolytic immune responses.

  9. ABH-related antigens in human male genital tract. A histochemical examination.

    PubMed

    Nishi, K; Fukunaga, T; Yamamoto, Y; Yamada, M; Kane, M; Tanegashima, A; Rand, S; Brinkmann, B

    1992-01-01

    The localization of ABH related antigens in human male reproductive tract was examined using monoclonal antibodies and an avidin biotin complex method. No positive reaction with blood group antibodies on spermatozoa was observed in testis and ductus epididymidis apart from erythrocytes and endothelial cells. The expression of ABH and ABH related antigens in ductuli efferents testis, ductus epididymidis, seminal vesicle and prostate was complexly coded by a combination of H, Se, Le and X genes. The results obtained in this study indicate that the ABH antigens detected on spermatozoa of seminal stains are coating antigens and not inherent to the cell membrane, and the ABO, H, Se, Le and X genes are subjected to a tissue-dependent differential expression. PMID:1520640

  10. 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

  11. 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.

  12. Identification of novel Mycobacterium tuberculosis CD4 T-cell antigens via high throughput proteome screening

    PubMed Central

    Nayak, Kaustuv; Jing, Lichen; Russell, Ronnie M.; Davies, D. Huw; Hermanson, Gary; Molina, Douglas M.; Liang, Xiaowu; Sherman, David R.; Kwok, William W.; Yang, Junbao; Kenneth, John; Ahamed, Syed F.; Chandele, Anmol; Kaja, Murali-Krishna; Koelle, David M.

    2015-01-01

    Elicitation of CD4 IFN-gamma T cell responses to Mycobacterium tuberculosis (MTB) is a rational vaccine strategy to prevent clinical tuberculosis. Diagnosis of MTB infection is based on T-cell immune memory to MTB antigens. The MTB proteome contains over four thousand open reading frames (ORFs). We conducted a pilot antigen identification study using 164 MTB proteins and MTB-specific T-cells expanded in vitro from 12 persons with latent MTB infection. Enrichment of MTB-reactive T-cells from PBMC used cell sorting or an alternate system compatible with limited resources. MTB proteins were used as single antigens or combinatorial matrices in proliferation and cytokine secretion readouts. Overall, our study found that 44 MTB proteins were antigenic, including 27 not previously characterized as CD4 T-cell antigens. Antigen truncation, peptide, NTM homology, and HLA class II tetramer studies confirmed malate synthase G (encoded by gene Rv1837) as a CD4 T-cell antigen. This simple, scalable system has potential utility for the identification of candidate MTB vaccine and biomarker antigens. PMID:25857935

  13. 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

  14. Detection of O antigens in Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lipopolysaccharide on the surface of Escherichia coli constitute the O antigens, which are important virulence factors that are targets of both the innate and adaptive immune system and play a major role in host-pathogen interactions. O antigens that are responsible for antigenic specificity of the ...

  15. Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production

    PubMed Central

    Vasilyeva, Anastasia; Santos Sanches, Ilda; Florindo, Carlos; Dmitriev, Alexander

    2015-01-01

    Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level. Inactivation of bgrR abrogated bac gene expression and increased virulence properties of S. agalactiae. In this study, a total of 140 strains were screened for the presence of bac gene, and the TCS bgrR and bgrS genes. A total of 53 strains carried the bac, bgrR and bgrS genes. Most of them (48 strains) expressed β antigen, while five strains did not express β antigen. Three strains, in which bac gene sequence was intact, while bgrR and/or bgrS genes had mutations, and expression of β antigen was absent, were complemented with a constructed plasmid pBgrRS(P) encoding functionally active bgrR and bgrS gene alleles. This procedure restored expression of β antigen indicating the crucial regulatory role of TCS BgrRS. The complemented strain A49V/BgrRS demonstrated attenuated virulence in intraperitoneal mice model of S. agalactiae infection compared to parental strain A49V. In conclusion we showed that disruption of β antigen expression is associated with: i) insertion of ISSa4 upstream the bac gene just after the ribosomal binding site; ii) point mutation G342A resulting a stop codon TGA within the bac gene and a truncated form of β antigen; iii) single deletion (G) in position 439 of the bgrR gene resulting in a frameshift and the loss of DNA-binding domain of the BgrR protein, and iv) single base substitutions in bgrR and bgrS genes causing single amino acid substitutions in BgrR (Arg187Lys) and BgrS (Arg252Gln). The fact that BgrRS negatively controls virulent properties of S. agalactiae gives a novel clue for understanding of S

  16. Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production.

    PubMed

    Vasilyeva, Anastasia; Santos Sanches, Ilda; Florindo, Carlos; Dmitriev, Alexander

    2015-01-01

    Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level. Inactivation of bgrR abrogated bac gene expression and increased virulence properties of S. agalactiae. In this study, a total of 140 strains were screened for the presence of bac gene, and the TCS bgrR and bgrS genes. A total of 53 strains carried the bac, bgrR and bgrS genes. Most of them (48 strains) expressed β antigen, while five strains did not express β antigen. Three strains, in which bac gene sequence was intact, while bgrR and/or bgrS genes had mutations, and expression of β antigen was absent, were complemented with a constructed plasmid pBgrRS(P) encoding functionally active bgrR and bgrS gene alleles. This procedure restored expression of β antigen indicating the crucial regulatory role of TCS BgrRS. The complemented strain A49V/BgrRS demonstrated attenuated virulence in intraperitoneal mice model of S. agalactiae infection compared to parental strain A49V. In conclusion we showed that disruption of β antigen expression is associated with: i) insertion of ISSa4 upstream the bac gene just after the ribosomal binding site; ii) point mutation G342A resulting a stop codon TGA within the bac gene and a truncated form of β antigen; iii) single deletion (G) in position 439 of the bgrR gene resulting in a frameshift and the loss of DNA-binding domain of the BgrR protein, and iv) single base substitutions in bgrR and bgrS genes causing single amino acid substitutions in BgrR (Arg187Lys) and BgrS (Arg252Gln). The fact that BgrRS negatively controls virulent properties of S. agalactiae gives a novel clue for understanding of S

  17. Structures of Preferred Human IgV Genes-Based Protective Antibodies Identify How Conserved Residues Contact Diverse Antigens and Assign Source of Specificity to CDR3 Loop Variation.

    PubMed

    Bryson, Steve; Thomson, Christy A; Risnes, Louise F; Dasgupta, Somnath; Smith, Kenneth; Schrader, John W; Pai, Emil F

    2016-06-01

    The human Ab response to certain pathogens is oligoclonal, with preferred IgV genes being used more frequently than others. A pair of such preferred genes, IGVK3-11 and IGVH3-30, contributes to the generation of protective Abs directed against the 23F serotype of the pneumonococcal capsular polysaccharide of Streptococcus pneumoniae and against the AD-2S1 peptide of the gB membrane protein of human CMV. Structural analyses of Fab fragments of mAbs 023.102 and pn132p2C05 in complex with portions of the 23F polysaccharide revealed five germline-encoded residues in contact with the key component, l-rhamnose. In the case of the AD-2S1 peptide, the KE5 Fab fragment complex identified nine germline-encoded contact residues. Two of these germline-encoded residues, Arg91L and Trp94L, contact both the l-rhamnose and the AD-2S1 peptide. Comparison of the respective paratopes that bind to carbohydrate and protein reveals that stochastic diversity in both CDR3 loops alone almost exclusively accounts for their divergent specificity. Combined evolutionary pressure by human CMV and the 23F serotype of S. pneumoniae acted on the IGVK3-11 and IGVH3-30 genes as demonstrated by the multiple germline-encoded amino acids that contact both l-rhamnose and AD-2S1 peptide. PMID:27183571

  18. Antigen Export Reduces Antigen Presentation and Limits T Cell Control of M. tuberculosis.

    PubMed

    Srivastava, Smita; Grace, Patricia S; Ernst, Joel D

    2016-01-13

    Persistence of Mycobacterium tuberculosis results from bacterial strategies that manipulate host adaptive immune responses. Infected dendritic cells (DCs) transport M. tuberculosis to local lymph nodes but activate CD4 T cells poorly, suggesting bacterial manipulation of antigen presentation. However, M. tuberculosis antigens are also exported from infected DCs and taken up and presented by uninfected DCs, possibly overcoming this blockade of antigen presentation by infected cells. Here we show that the first stage of this antigen transfer, antigen export, benefits M. tuberculosis by diverting bacterial proteins from the antigen presentation pathway. Kinesin-2 is required for antigen export and depletion of this microtubule-based motor increases activation of antigen-specific CD4 T cells by infected cells and improves control of intracellular infection. Thus, although antigen transfer enables presentation by bystander cells, it does not compensate for reduced antigen presentation by infected cells and represents a bacterial strategy for CD4 T cell evasion. PMID:26764596

  19. HLA antigens and insulin dependent diabetes mellitus. A family study.

    PubMed

    Savi, M; Neri, T M; Zavaroni, I; Coscelli, I

    1977-12-01

    Sixteen insulin dependent diabetic patients (age at onset less than 35 years) and their families were tissue typed for HLA antigens. Glucose tolerance of relatives was also tested. Among diabetic patients two HLA antigens were found with increased frequency: B8 (31 percent, control 15 percent) and Bw35 (38 percent, control 23 percent). Among normal relatives B8 and Bw35 had the same frequency as the control group. Bw15 frequency was not increased in either group. In relatives, no correlation between HLA antigens (B8 or Bw35) and abnormal glucose tolerance, obesity and over-weight at birth was found. Present data confirm previous reports of high B8 frequency in early onset diabetic patients, but fail to demonstrate a raised frequency of abnormal glucose tolerance among relatives bearing B8 (or, in our cases, Bw35). B8 may be considered a genetic indicator for susceptibility to juvenile diabetes. On the basis of present results in families, however non genetic factors clearly also play a determinant role. Furthermore, that diabetogenesis arises from a link between Ir-genes and HLA-B8 antigen should only be considered a suggestive hypothesis. PMID:413751

  20. COMPARISON OF SOLUBLE HUMAN AND MOUSE TRANSPLANTATION ANTIGENS*

    PubMed Central

    Mann, Dean L.; Nathenson, Stanley G.

    1969-01-01

    The molecular and chemical characteristics of membrane components bearing the major transplantation antigen systems in mouse (H-2) and man (HL-A) were compared and found to be strikingly similar. Kinetics of papain solubilization from cell membranes, gel filtration, and electrophoretic patterns of the alloantigenic components were found to be nearly identical. Comparable size heterogeneity of the solubilized materials was also demonstrated. Some differences in amino acid and carbohydrate content of the purified H-2 and HL-A alloantigenic materials were found. The general pattern of distribution of the amino acid residues, however, appears to be quite similar and indicate compositional relatedness in these materials. These physical and chemical similarities in the characteristics of molecules bearing the transplantation antigens are in accord with biologic studies indicating a comparable functional immunologic role for the mouse H-2 and human HL-A antigen systems. These studies support the view that the genes determining these major transplantation antigen systems may have evolved from a common precursor. Images PMID:5271759

  1. Immunization with viral antigens: infectious haematopoietic necrosis.

    PubMed

    Winton, J R

    1997-01-01

    Infectious haematopoietic necrosis (IHN) is one of the most important viral diseases of salmonids, especially among juvenile fish where losses can be high. For over 20 years, researchers have tested a variety of preparations for control of IHN. Early vaccines consisted of killed virus and were effective when delivered by injection, but too costly to be practical on a large scale. Attenuated vaccines were developed by serial passage in cell culture and by monoclonal antibody selection. These offered excellent protection and were cost-effective, but residual virulence and uncertainty about their effects on other aquatic species made them poor candidates for licensing. Subunit vaccines using part of the IHNV glycoprotein gene cloned into E. coli or into an attenuated strain of A. salmonicida have been tested, appeared safe and were inexpensive. These vaccines were reported to provide some protection when delivered by immersion. Information on the location of antigenic sites on the glycoprotein led to trials using synthetic peptides, but these did not seem to be economically viable. Recently, plasmid vectors encoding the glycoprotein gene under control of a cytomegalovirus promoter were developed for genetic immunization. The constructs were highly protective when delivered by injection, but a more practical delivery system is needed. Thus, while several vaccine strategies have been tried in order to stimulate specific immunity against IHN, more research is needed to develop a commercially viable product for control of this important disease. PMID:9270850

  2. Molecular cloning, gene organization and expression of the human UDP-GalNAc:Neu5Acalpha2-3Galbeta-R beta1,4-N-acetylgalactosaminyltransferase responsible for the biosynthesis of the blood group Sda/Cad antigen: evidence for an unusual extended cytoplasmic domain.

    PubMed Central

    Montiel, Maria-Dolores; Krzewinski-Recchi, Marie-Ange; Delannoy, Philippe; Harduin-Lepers, Anne

    2003-01-01

    The nucleotide sequence of the short and long transcripts of beta1,4- N -acetylgalactosaminyltransferase have been submitted to the DDBJ, EMBL, GenBank(R) and GSDB Nucleotide Sequence Databases under accession nos AJ517770 and AJ517771 respectively. The human Sd(a) antigen is formed through the addition of an N -acetylgalactosamine residue via a beta1,4-linkage to a sub-terminal galactose residue substituted with an alpha2,3-linked sialic acid residue. We have taken advantage of the previously cloned mouse cDNA sequence of the UDP-GalNAc:Neu5Acalpha2-3Galbeta-R beta1,4- N -acetylgalactosaminyltransferase (Sd(a) beta1,4GalNAc transferase) to screen the human EST and genomic databases and to identify the corresponding human gene. The sequence spans over 35 kb of genomic DNA on chromosome 17 and comprises at least 12 exons. As judged by reverse transcription PCR, the human gene is expressed widely since it is detected in various amounts in almost all cell types studied. Northern blot analysis indicated that five Sd(a) beta1,4GalNAc transferase transcripts of 8.8, 6.1, 4.7, 3.8 and 1.65 kb were highly expressed in colon and to a lesser extent in kidney, stomach, ileum and rectum. The complete coding nucleotide sequence was amplified from Caco-2 cells. Interestingly, the alternative use of two first exons, named E1(S) and E1(L), leads to the production of two transcripts. These nucleotide sequences give rise potentially to two proteins of 506 and 566 amino acid residues, identical in their sequence with the exception of their cytoplasmic tail. The short form is highly similar (74% identity) to the mouse enzyme whereas the long form shows an unusual long cytoplasmic tail of 66 amino acid residues that is as yet not described for any other mammalian glycosyltransferase. Upon transient transfection in Cos-7 cells of the common catalytic domain, a soluble form of the protein was obtained, which catalysed the transfer of GalNAc residues to alpha2,3-sialylated acceptor

  3. [Polyagglutinability due to Hempas antigen].

    PubMed

    Rochant, H; Gerbal, A

    1976-03-01

    A new antigen has been recently discoverd in patients with congenital dyserythropoietic anemia type II. The acronyme Hempas was proposed for this disease as a remind of the main morphological feature of erythroblasts (hereditary erythroblastic multinuclearity) and the characteristic serological findings (positive acidified serum test). The patients red cells are agglutinated and lysed by an IgM cold reacting antibody present in the serum of most normal subjects and not previously recognized. This behaviour is thus reminding of cells carrying antigens such as T, Tn, Cad or acquired B. As for T and Tn cells, sialic acid and electrophoretic mobility are reduced, but in contrast, agglutinability of Hempas cells is enhanced by enzyme treatment. Agglutination by anti H and anti Pr specific reagents is reduced. I and mainly i activity are strongly increased. The relationship between the membrane abnormalities of Hempas red cells and the failure of normoblasts to divide their cytoplasm i still largely unknown. PMID:788106

  4. Common antigens between hydatid cyst and cancers

    PubMed Central

    Daneshpour, Shima; Bahadoran, Mehran; Hejazi, Seyed Hossein; Eskandarian, Abas Ali; Mahmoudzadeh, Mehdi; Darani, Hossein Yousofi

    2016-01-01

    Background: Different research groups reported a negative correlation between cancers and parasitical infections. As an example, the prevalence of a hydatid cyst among patients with cancer was significantly lower than its prevalence among normal population. Tn antigens exist both in cancer and hydatid cyst. This common antigen may be involved in the effect of parasite on cancer growth. So in this work, common antigens between hydatid cyst and cancers have been investigated. Materials and Methods: Different hydatid cyst antigens including hydatid fluid, laminated and germinal layer antigens, and excretory secretory antigens of protoscolices were run in SDS PAGE and transferred to NCP paper. In western immunoblotting, those antigens were probed with sera of patients with different cancer and also sera of non-cancer patients. Also, cross reaction among excretory secretory products of cancer cells and antisera raised against different hydatid cyst antigen was investigated. Results: In western immunoblotting, antisera raised against laminated and germinal layers of hydatid cyst reacted with excretory secretory products of cancer cells. Also, a reaction was detected between hydatid cyst antigens and sera of patients with some cancers. Conclusion: Results of this work emphasize existence of common antigens between hydatid cyst and cancers. More investigation about these common antigens is recommended. PMID:26962511

  5. HLA antigen changes in malignant cells: epigenetic mechanisms and biologic significance

    PubMed Central

    Campoli, Michael; Ferrone, Soldano

    2009-01-01

    Changes in classical and non-classical HLA class I as well as HLA class II antigens have been identified in malignant lesions. These changes which are described in this paper are believed to play a major role in the clinical course of the disease since both HLA class I and class II antigens are critical to the interaction between tumor cells and components of both innate and adaptive immune system. Abnormalities in HLA antigen expression in malignant cells, which range in frequency from 0-90%, are caused by distinct mechanisms. They include defects in β2-microglobulin (β2m) synthesis, loss of the gene(s) encoding HLA antigen heavy chain(s), mutations which inhibit HLA antigen heavy chain transcription or translation, defects in the regulatory mechanisms which control HLA antigen expression and/or abnormalities in one or more of the antigen processing machinery (APM) components. More recently, epigenetic events associated with tumor development and progression have been found to underlie changes in HLA antigen, APM component, co-stimulatory molecule and TA expression in malignant cells. The types of epigenetic modifications that may occur in normal and malignant cells as well as their role underlying changes in HLA expression by malignant cells have been reviewed. The epigenetic events associated with alterations in HLA antigen expression may be clinically relevant since, in some case, they have been shown to impair the recognition of tumor cells by components of the adaptive immune system. The functional relevance and potential clinical significance of these epigenetic alterations have been addressed. Lastly, unlike genetic alterations, epigenetic modifications can, in some cases, be reversed with pharmacologic agents that induce DNA hypomethylation or inhibit histone deacetylation. Therefore strategies to overcome epigenetic modifications underlying changes in HLA expression in malignant cells have been discussed. PMID:18836468

  6. The Genetic and Molecular Basis of O-Antigenic Diversity in Burkholderia pseudomallei Lipopolysaccharide

    PubMed Central

    Tuanyok, Apichai; Stone, Joshua K.; Mayo, Mark; Kaestli, Mirjam; Gruendike, Jeffrey; Georgia, Shalamar; Warrington, Stephanie; Mullins, Travis; Allender, Christopher J.; Wagner, David M.; Chantratita, Narisara; Peacock, Sharon J.; Currie, Bart J.; Keim, Paul

    2012-01-01

    Lipopolysaccharide (LPS) is one of the most important virulence and antigenic components of Burkholderia pseudomallei, the causative agent of melioidosis. LPS diversity in B. pseudomallei has been described as typical, atypical or rough, based upon banding patterns on SDS-PAGE. Here, we studied the genetic and molecular basis of these phenotypic differences. Bioinformatics was used to determine the diversity of genes known or predicted to be involved in biosynthesis of the O-antigenic moiety of LPS in B. pseudomallei and its near-relative species. Multiplex-PCR assays were developed to target diversity of the O-antigen biosynthesis gene patterns or LPS genotypes in B. pseudomallei populations. We found that the typical LPS genotype (LPS genotype A) was highly prevalent in strains from Thailand and other countries in Southeast Asia, whereas the atypical LPS genotype (LPS genotype B) was most often detected in Australian strains (∼13.8%). In addition, we report a novel LPS ladder pattern, a derivative of the atypical LPS phenotype, associated with an uncommon O-antigen biosynthesis gene cluster that is found in only a small B. pseudomallei sub-population. This new LPS group was designated as genotype B2. We also report natural mutations in the O-antigen biosynthesis genes that potentially cause the rough LPS phenotype. We postulate that the diversity of LPS may correlate with differential immunopathogenicity and virulence among B. pseudomallei strains. PMID:22235357

  7. 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

  8. Natural micropolymorphism in human leukocyte antigens provides a basis for genetic control of antigen recognition

    SciTech Connect

    Archbold, Julia K.; Macdonald, Whitney A.; Gras, Stephanie; Ely, Lauren K.; Miles, John J.; Bell, Melissa J.; Brennan, Rebekah M.; Beddoe, Travis; Wilce, Matthew C.J.; Clements, Craig S.; Purcell, Anthony W.; McCluskey, James; Burrows, Scott R.; Rossjohn, Jamie

    2009-07-10

    Human leukocyte antigen (HLA) gene polymorphism plays a critical role in protective immunity, disease susceptibility, autoimmunity, and drug hypersensitivity, yet the basis of how HLA polymorphism influences T cell receptor (TCR) recognition is unclear. We examined how a natural micropolymorphism in HLA-B44, an important and large HLA allelic family, affected antigen recognition. T cell-mediated immunity to an Epstein-Barr virus determinant (EENLLDFVRF) is enhanced when HLA-B*4405 was the presenting allotype compared with HLA-B*4402 or HLA-B*4403, each of which differ by just one amino acid. The micropolymorphism in these HLA-B44 allotypes altered the mode of binding and dynamics of the bound viral epitope. The structure of the TCR-HLA-B*4405EENLLDFVRF complex revealed that peptide flexibility was a critical parameter in enabling preferential engagement with HLA-B*4405 in comparison to HLA-B*4402/03. Accordingly, major histocompatibility complex (MHC) polymorphism can alter the dynamics of the peptide-MHC landscape, resulting in fine-tuning of T cell responses between closely related allotypes.

  9. 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

  10. Innovative Strategies to Identify M. tuberculosis Antigens and Epitopes Using Genome-Wide Analyses.

    PubMed

    Geluk, Annemieke; van Meijgaarden, Krista E; Joosten, Simone A; Commandeur, Susanna; Ottenhoff, Tom H M

    2014-01-01

    In view of the fact that only a small part of the Mtb expressome has been explored for identification of antigens capable of activating human T-cell responses, which is critically required for the design of better TB vaccination strategies, more emphasis should be placed on innovative ways to discover new Mtb antigens and explore their function at the several stages of infection. Better protective antigens for TB-vaccines are urgently needed, also in view of the disappointing results of the MVA85 vaccine, which failed to induce additional protection in BCG-vaccinated infants (1). Moreover, immune responses to relevant antigens may be useful to identify TB-specific biomarker signatures. Here, we describe the potency of novel tools and strategies to reveal such Mtb antigens. Using proteins specific for different Mtb infection phases, many new antigens of the latency-associated Mtb DosR-regulon as well as resuscitation promoting factor proteins, associated with resuscitating TB, were discovered that were recognized by CD4(+) and CD8(+) T-cells. Furthermore, by employing MHC binding algorithms and bioinformatics combined with high-throughput human T-cell screens and tetramers, HLA-class Ia restricted polyfunctional CD8(+) T-cells were identified in TB patients. Comparable methods, led to the identification of HLA-E-restricted Mtb epitopes recognized by CD8(+) T-cells. A genome-wide unbiased antigen discovery approach was applied to analyze the in vivo Mtb gene expression profiles in the lungs of mice, resulting in the identification of IVE-TB antigens, which are expressed during infection in the lung, the main target organ of Mtb. IVE-TB antigens induce strong T-cell responses in long-term latently Mtb infected individuals, and represent an interesting new group of TB antigens for vaccination. In summary, new tools have helped expand our view on the Mtb antigenome involved in human cellular immunity and provided new candidates for TB vaccination. PMID:25009541

  11. Roles of Predicted Glycosyltransferases in the Biosynthesis of the Rhizobium etli CE3 O Antigen

    PubMed Central

    Ojeda, Kristylea J.; Simonds, Laurie

    2013-01-01

    The Rhizobium etli CE3 O antigen is a fixed-length heteropolymer. The genetic regions required for its synthesis have been identified, and the nucleotide sequences are known. The structure of the O antigen has been determined, but the roles of specific genes in synthesizing this structure are relatively unclear. Within the known O-antigen genetic clusters of this strain, nine open reading frames (ORFs) were found to contain a conserved glycosyltransferase domain. Each ORF was mutated, and the resulting mutant lipopolysaccharide (LPS) was analyzed. Tricine SDS-PAGE revealed stepwise truncations of the O antigen that were consistent with differences in mutant LPS sugar compositions and reactivity with O-antigen-specific monoclonal antibodies. Based on these results and current theories of O-antigen synthesis, specific roles were deduced for each of the nine glycosyltransferases, and a model for biosynthesis of the R. etli CE3 O antigen was proposed. In this model, O-antigen biosynthesis is initiated with the addition of N-acetyl-quinovosamine-phosphate (QuiNAc-P) to bactoprenol-phosphate by glycosyltransferase WreU. Glycosyltransferases WreG, WreE, WreS, and WreT would each act once to attach mannose, fucose, a second fucose, and 3-O-methyl-6-deoxytalose (3OMe6dTal), respectively. WreH would then catalyze the addition of methyl glucuronate (MeGlcA) to complete the first instance of the O-antigen repeat unit. Four subsequent repeats of this unit composed of fucose, 3OMe6dTal, and MeGlcA would be assembled by a cycle of reactions catalyzed by two additional glycosyltransferases, WreM and WreL, along with WreH. Finally, the O antigen would be capped by attachment of di- or tri-O-methylated fucose as catalyzed by glycosyltransferase WreB. PMID:23435981

  12. Innovative Strategies to Identify M. tuberculosis Antigens and Epitopes Using Genome-Wide Analyses

    PubMed Central

    Geluk, Annemieke; van Meijgaarden, Krista E.; Joosten, Simone A.; Commandeur, Susanna; Ottenhoff, Tom H. M.

    2014-01-01

    In view of the fact that only a small part of the Mtb expressome has been explored for identification of antigens capable of activating human T-cell responses, which is critically required for the design of better TB vaccination strategies, more emphasis should be placed on innovative ways to discover new Mtb antigens and explore their function at the several stages of infection. Better protective antigens for TB-vaccines are urgently needed, also in view of the disappointing results of the MVA85 vaccine, which failed to induce additional protection in BCG-vaccinated infants (1). Moreover, immune responses to relevant antigens may be useful to identify TB-specific biomarker signatures. Here, we describe the potency of novel tools and strategies to reveal such Mtb antigens. Using proteins specific for different Mtb infection phases, many new antigens of the latency-associated Mtb DosR-regulon as well as resuscitation promoting factor proteins, associated with resuscitating TB, were discovered that were recognized by CD4+ and CD8+ T-cells. Furthermore, by employing MHC binding algorithms and bioinformatics combined with high-throughput human T-cell screens and tetramers, HLA-class Ia restricted polyfunctional CD8+ T-cells were identified in TB patients. Comparable methods, led to the identification of HLA-E-restricted Mtb epitopes recognized by CD8+ T-cells. A genome-wide unbiased antigen discovery approach was applied to analyze the in vivo Mtb gene expression profiles in the lungs of mice, resulting in the identification of IVE-TB antigens, which are expressed during infection in the lung, the main target organ of Mtb. IVE-TB antigens induce strong T-cell responses in long-term latently Mtb infected individuals, and represent an interesting new group of TB antigens for vaccination. In summary, new tools have helped expand our view on the Mtb antigenome involved in human cellular immunity and provided new candidates for TB vaccination. PMID:25009541

  13. A critical examination of the numerology of antigen-binding cells: evidence for multiple receptor specificities on single cells.

    PubMed

    Miller, A

    1977-01-01

    The data available from other laboratories as well as our own on the frequency of cells recognizing major histocompatibility antigens or conventional protein and hapten antigens is critically evaluated. The frequency of specific binding for a large number of antigens is sufficiently high to support the idea that at least part of the antigen-binding cell population must have multiple specificities. Our results suggest that these multiple specific cells result from single cells synthesizing and displaying as many as 50-100 species of receptor, each at a frequency of 10(4) per cell. A model involving gene expansion of constant-region genes is suggested and some auxilliary evidence consistent with such C-gene expansion is presented. PMID:68706

  14. Role of the wbt locus of Francisella tularensis in lipopolysaccharide O-antigen biogenesis and pathogenicity.

    PubMed

    Raynaud, Catherine; Meibom, Karin L; Lety, Marie-Annick; Dubail, Iharilalao; Candela, Thomas; Frapy, Eric; Charbit, Alain

    2007-01-01

    Francisella tularensis is a highly infectious bacterial pathogen, responsible for the zoonotic disease tularemia. We screened a bank of transposon insertion mutants of F. tularensis subsp. holarctica LVS for colony morphology alterations and selected a mutant with a transposon insertion in wbtA, the first gene of the predicted lipopolysaccharide O-antigen gene cluster. Inactivation of wbtA led to the complete loss of O antigen, conferred serum sensitivity, impaired intracellular replication, and severely attenuated virulence in the mouse model. Notably, this mutant afforded protection against a challenge against virulent LVS. PMID:17030571

  15. Epstein-Barr virus nuclear antigen 2 specifically induces expression of the B-cell activation antigen CD23

    SciTech Connect

    Wang, F.; Gregory, C.D.; Rowe, M.; Rickinson, A.B.; Wang, D.; Birkenbach, M.; Kikutani, H.; Kishimoto, T.; Kieff, E.

    1987-05-01

    Epstein-Barr virus (EBV) infection of EBV-negative Burkitt lymphoma (BL) cells includes some changes similar to those seen in normal B lymphocytes that have been growth transformed by EBV. The role of individual EBV genes in this process was evaluated by introducing each of the viral genes that are normally expressed in EBV growth-transformed and latently infected lymphoblasts into an EBV-negative BL cell line, using recombinant retrovirus-mediated transfer. Clones of cells were derived that stably express the EBV nuclear antigen 1 (EBNA-1), EBNA-2, EBNA-3, EBNA-leader protein, or EBV latent membrane protein (LMP). These were compared with control clones infected with the retrovirus vector. All 10 clones converted to EBNA-2 expression differed from control clones or clones expressing other EBV proteins by growth in tight clumps and by markedly increased expression of one particular surface marker of B-cell activation, CD23. Other activation antigens were unaffected by EBNA-2 expression, as were markers already expressed on the parent BL cell line. The results indicate that EBNA-2 is a specific direct or indirect trans-activator of CD23. This establishes a link between an EBV gene and cell gene expression. Since CD23 has been implicated in the transduction of B-cell growth signals, its specific induction by EBNA-2 could be important in EBV induction of B-lymphocyte transformation.

  16. Cell Wall Anchoring of the Campylobacter Antigens to Lactococcus lactis.

    PubMed

    Kobierecka, Patrycja A; Olech, Barbara; Książek, Monika; Derlatka, Katarzyna; Adamska, Iwona; Majewski, Paweł M; Jagusztyn-Krynicka, Elżbieta K; Wyszyńska, Agnieszka K

    2016-01-01

    Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein - CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type C. jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analyzed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ Lactic Acid Bacteria (LAB) strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered as an alternative vector to

  17. Cell Wall Anchoring of the Campylobacter Antigens to Lactococcus lactis

    PubMed Central

    Kobierecka, Patrycja A.; Olech, Barbara; Książek, Monika; Derlatka, Katarzyna; Adamska, Iwona; Majewski, Paweł M.; Jagusztyn-Krynicka, Elżbieta K.; Wyszyńska, Agnieszka K.

    2016-01-01

    Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein – CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type C. jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analyzed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ Lactic Acid Bacteria (LAB) strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered as an alternative vector to

  18. The symbiotic role of O-antigen of Burkholderia symbiont in association with host Riptortus pedestris.

    PubMed

    Kim, Jiyeun Kate; Park, Ha Young; Lee, Bok Luel

    2016-07-01

    Riptortus pedestris harboring Burkholderia symbiont is a useful symbiosis model to study the molecular interactions between insects and bacteria. We recently reported that the lipopolysaccharide O-antigen is absent in the Burkholderia symbionts isolated from Riptortus guts. Here, we investigated the symbiotic role of O-antigen comprehensively in the Riptortus-Burkholderia model. Firstly, Burkholderia mutant strains deficient of O-antigen biosynthesis genes were generated and confirmed for their different patterns of the lipopolysaccharide by electrophoretic analysis. The O-antigen-deficient mutant strains initially exhibited a reduction of infectivity, having significantly lower level of symbiont population at the second-instar stage. However, both the wild-type and O-antigen mutant symbionts exhibited a similar level of symbiont population from the third-instar stage, indicating that the O-antigen deficiency did not affect the bacterial persistence in the host midgut. Taken together, we showed that the lipopolysaccharide O-antigen of gut symbiont plays an exclusive role in the initial symbiotic association. PMID:26875632

  19. Mini-review: Strategies for Variation and Evolution of Bacterial Antigens

    PubMed Central

    Foley, Janet

    2015-01-01

    Across the eubacteria, antigenic variation has emerged as a strategy to evade host immunity. However, phenotypic variation in some of these antigens also allows the bacteria to exploit variable host niches as well. The specific mechanisms are not shared-derived characters although there is considerable convergent evolution and numerous commonalities reflecting considerations of natural selection and biochemical restraints. Unlike in viruses, mechanisms of antigenic variation in most bacteria involve larger DNA movement such as gene conversion or DNA rearrangement, although some antigens vary due to point mutations or modified transcriptional regulation. The convergent evolution that promotes antigenic variation integrates various evolutionary forces: these include mutations underlying variant production; drift which could remove alleles especially early in infection or during life history phases in arthropod vectors (when the bacterial population size goes through a bottleneck); selection not only for any particular variant but also for the mechanism for the production of variants (i.e., selection for mutability); and overcoming negative selection against variant production. This review highlights the complexities of drivers of antigenic variation, in particular extending evaluation beyond the commonly cited theory of immune evasion. A deeper understanding of the diversity of purpose and mechanisms of antigenic variation in bacteria will contribute to greater insight into bacterial pathogenesis, ecology and coevolution with hosts. PMID:26288700

  20. Direct Introduction of Genes into Rats and Expression of the Genes

    NASA Astrophysics Data System (ADS)

    Benvenisty, Nissim; Reshef, Lea

    1986-12-01

    A method of introducing actively expressed genes into intact mammals is described. DNA precipitated with calcium phosphate has been injected intraperitoneally into newborn rats. The injected genes have been taken up and expressed by the animal tissues. To examine the generality of the method we have injected newborn rats with the chloramphenicol acetyltransferase prokaryotic gene fused with various viral and cellular gene promoters and the gene for hepatitis B surface antigen, and we observed appearance of chloramphenicol acetyltransferase activity and hepatitis B surface antigen in liver and spleen. In addition, administration of genes coding for hormones (insulin or growth hormone) resulted in their expression.

  1. Viruses, cytokines, antigens, and autoimmunity.

    PubMed Central

    Gianani, R; Sarvetnick, N

    1996-01-01

    To explain the pathogenesis of autoimmunity, we hypothesize that following an infection the immune response spreads to tissue-specific autoantigens in genetically predisposed individuals eventually determining progression to disease. Molecular mimicry between viral and self antigens could, in some instances, initiate autoimmunity. Local elicitation of inflammatory cytokines following infection probably plays a pivotal role in determining loss of functional tolerance to self autoantigens and the destructive activation of autoreactive cells. We also describe the potential role of interleukin 10, a powerful B-cell activator, in increasing the efficiency of epitope recognition, that could well be crucial to the progression toward disease. PMID:8637859

  2. Antigenic and genetic evolution of equine H3N8 influenza A viruses.

    PubMed

    Daly, J M; Lai, A C; Binns, M M; Chambers, T M; Barrandeguy, M; Mumford, J A

    1996-04-01

    Evolution of equine influenza a H3N8 viruses was examined by antigenic and genetic analysis of a collection isolates from around the world. It was noted that antigenic and genetic variants of equine H3N8 viruses cocirculate, and in particular that variants currently circulating in Europe and the USA are distinguishable from one another both in terms of antigenic reactivity and genetic structure of the HA1 portion of the haemagglutinin (HA) molecule. Whilst the divergent evolution of American and European isolates may be due to geographical isolation of the two gene pools, some mixing is believed to occur as 'American-like' viruses have been isolated during outbreaks of equine influenza in the UK. The cocirculation of two antigenically and genetically distinct lineages of equine influenza H3N8 viruses has serious implications for vaccine strain selection. PMID:8627254

  3. [Structure and function of the T-lymphocyte antigen receptor and its role in infectious diseases].

    PubMed

    Peralta Zaragoza, O; Sánchez Magaña, T; Barrera Rodriguez, R; Madrid Marina, V

    1996-01-01

    The T lymphocytes recognize antigens through antigen receptors (TcRs) and the major histocompatibility complex (MHC) molecules: they lysate the cells that bear the antigen, or release cytokines that are mediators of the immune response. The TcRs recognize antigens in the form of short peptides bound to MHC molecules. So far, there are two isotypes of TcR: gamma/delta and alpha/beta, which appear in the sequence during T-cell ontogeny. The process of selection of TcRs during thymic ontogeny obeys to molecular mechanisms which generate intracellular events that will participate in the gene expression of the TcR. The aim of the present paper is to review the molecular, structural, and functional aspects of the TcRs, and their role in human autoimmune infectious disease. PMID:8815490

  4. Lamprey VLRB response to influenza virus supports universal rules of immunogenicity and antigenicity.

    PubMed

    Altman, Meghan O; Bennink, Jack R; Yewdell, Jonathan W; Herrin, Brantley R

    2015-01-01

    Immunoglobulins (Igs) are a crown jewel of jawed vertebrate evolution. Through recombination and mutation of small numbers of genes, Igs can specifically recognize a vast variety of natural and man-made organic molecules. Jawless vertebrates evolved a parallel system of humoral immunity, which recognizes antigens not with Ig, but with a structurally unrelated receptor called the variable lymphocyte receptor B (VLRB). We exploited the convergent evolution of Ig and VLRB antibodies (Abs) to investigate if intrinsic chemical features of foreign proteins determine their antigenicity and immunogenicity. Surprisingly, we find lamprey VLRB and mouse Ig responses to influenza A virus are extremely similar. Each focuses ~80% of the response on hemagglutinin (HA), mainly through recognition of the major antigenic sites in the HA globular head domain. Our findings predict basic conservation of Ab responses to protein antigens, strongly supporting the use of animal models for understanding human Ab responses to viruses and protein immunogens. PMID:26252514

  5. Nuclear localization of Merkel cell polyomavirus large T antigen in Merkel cell carcinoma

    SciTech Connect

    Nakamura, Tomoyuki; Sato, Yuko; Watanabe, Daisuke; Ito, Hideki; Shimonohara, Nozomi; Tsuji, Takahiro; Nakajima, Noriko; Suzuki, Yoshio; Matsuo, Koma; Nakagawa, Hidemi; Sata, Tetsutaro; Katano, Harutaka

    2010-03-15

    To clarify whether mutations in the large T gene encoded by Merkel cell polyomavirus affect the expression and function of large T antigen in Merkel cell carcinoma cases, we investigated the expression of large T antigen in vitro and in vivo. Immunohistochemistry using a rabbit polyclonal antibody revealed that large T antigen was expressed in the nuclei of Merkel cell carcinoma cells with Merkel cell polyomavirus infection. Deletion mutant analyses identified an Arg-Lys-Arg-Lys sequence (amino acids 277-280) as a nuclear localization signal in large T antigen. Sequence analyses revealed that there were no mutations in the nuclear localization signal in any of the eleven Merkel cell polyomavirus strains examined. Furthermore, stop codons were not observed in the upstream of the nuclear localization signal in any of the Merkel cell carcinoma cases examined. These data suggest that the nuclear localization signal is highly conserved and functional in Merkel cell carcinoma cases.

  6. 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

  7. Persistence of antigen in nonarthritic joints.

    PubMed Central

    Fox, A; Glynn, L E

    1975-01-01

    The presence of antigen, IgG and C3 was shown by radioautography and immunofluorescence in the collagenous tissues of the joints of animals injected intra-articularly with antigen after having been previously immunized with that antigen in Freund's incomplete adjuvant. Since these joints were shown to be virtually free of inflammatory reactions, we suggest that the persistence of immune complexes activating complement cannot fully explain the chronicity of experimental allergic arthritis. Images PMID:769709

  8. Diagnostic markers of ovarian cancer by high-throughput antigen cloning and detection on arrays.

    PubMed

    Chatterjee, Madhumita; Mohapatra, Saroj; Ionan, Alexei; Bawa, Gagandeep; Ali-Fehmi, Rouba; Wang, Xiaoju; Nowak, James; Ye, Bin; Nahhas, Fatimah A; Lu, Karen; Witkin, Steven S; Fishman, David; Munkarah, Adnan; Morris, Robert; Levin, Nancy K; Shirley, Natalie N; Tromp, Gerard; Abrams, Judith; Draghici, Sorin; Tainsky, Michael A

    2006-01-15

    A noninvasive screening test would significantly facilitate early detection of epithelial ovarian cancer. This study used a combination of high-throughput selection and array-based serologic detection of many antigens indicative of the presence of cancer, thereby using the immune system as a biosensor. This high-throughput selection involved biopanning of an ovarian cancer phage display library using serum immunoglobulins from an ovarian cancer patient as bait. Protein macroarrays containing 480 of these selected antigen clones revealed 65 clones that interacted with immunoglobulins in sera from 32 ovarian cancer patients but not with sera from 25 healthy women or 14 patients having other benign or malignant gynecologic diseases. Sequence analysis data of these 65 clones revealed 62 different antigens. Among the markers, we identified some known antigens, including RCAS1, signal recognition protein-19, AHNAK-related sequence, nuclear autoantogenic sperm protein, Nijmegen breakage syndrome 1 (Nibrin), ribosomal protein L4, Homo sapiens KIAA0419 gene product, eukaryotic initiation factor 5A, and casein kinase II, as well as many previously uncharacterized antigenic gene products. Using these 65 antigens on protein microarrays, we trained neural networks on two-color fluorescent detection of serum IgG binding and found an average sensitivity and specificity of 55% and 98%, respectively. In addition, the top 6 of the most specific clones resulted in an average sensitivity and specificity of 32% and 94%, respectively. This global approach to antigenic profiling, epitomics, has applications to cancer and autoimmune diseases for diagnostic and therapeutic studies. Further work with larger panels of antigens should provide a comprehensive set of markers with sufficient sensitivity and specificity suitable for clinical testing in high-risk populations. PMID:16424057

  9. HLA antigens in cardiomyopathic Chilean chagasics.

    PubMed Central

    Llop, E; Rothhammer, F; Acuña, M; Apt, W

    1988-01-01

    The distribution of HLA antigens in a sample of 124 Chagas serologically positive Chilean individuals was studied. The sample was subdivided according to the presence or absence of chagasic cardiomyopathy, in order to search for genetic differences associated with this pathological condition. The frequency of antigen B40 in the presence of antigen Cw3 was found to be significantly lower in subjects with cardiomyopathy. We tentatively suggest that the presence of these antigens among noncardiomyopathics is associated with a decreased susceptibility to develop chagasic cardiomyopathy in the Chilean population. PMID:3189340

  10. Integrating influenza antigenic dynamics with molecular evolution

    PubMed Central

    Bedford, Trevor; Suchard, Marc A; Lemey, Philippe; Dudas, Gytis; Gregory, Victoria; Hay, Alan J; McCauley, John W; Russell, Colin A; Smith, Derek J; Rambaut, Andrew

    2014-01-01

    Influenza viruses undergo continual antigenic evolution allowing mutant viruses to evade host immunity acquired to previous virus strains. Antigenic phenotype is often assessed through pairwise measurement of cross-reactivity between influenza strains using the hemagglutination inhibition (HI) assay. Here, we extend previous approaches to antigenic cartography, and simultaneously characterize antigenic and genetic evolution by modeling the diffusion of antigenic phenotype over a shared virus phylogeny. Using HI data from influenza lineages A/H3N2, A/H1N1, B/Victoria and B/Yamagata, we determine patterns of antigenic drift across viral lineages, showing that A/H3N2 evolves faster and in a more punctuated fashion than other influenza lineages. We also show that year-to-year antigenic drift appears to drive incidence patterns within each influenza lineage. This work makes possible substantial future advances in investigating the dynamics of influenza and other antigenically-variable pathogens by providing a model that intimately combines molecular and antigenic evolution. DOI: http://dx.doi.org/10.7554/eLife.01914.001 PMID:24497547

  11. Nonprostatic sources of prostate-specific antigen.

    PubMed

    Diamandis, E P; Yu, H

    1997-05-01

    The name prostate-specific antigen has been given to a protein that now is known not to be prostate-specific; however, prostatic tissue does produces extremely high levels of PSA and secrets it into the seminal plasma. Seminal plasma contains about 1 million micrograms/L of PSA and is the richest source of PSA reported. The biologic fluid with the second highest PSA concentration, however, is nipple aspirate fluid from the female breast (up to about 5000 micrograms/L), and the third is milk from lactating women (up to 300 micrograms/L). Male serum PSA is usually less than 4 micrograms/L. In nonprostatic tissues, PSA exists mainly in its free molecular form, but PSA-ACT complex is also present in most of the fluids that contain PSA, such as breast secretions and amniotic fluid. The gene expression and protein production of PSA in nonprostatic tissues are under the regulation of steroid hormones via their receptors. Androgens, glucocorticoids, and progestins up-regulate the PSA gene expression, resulting in an increase of protein production. Estrogen by itself seems to have no effect on PSA regulation, but it can impair PSA production induced by androgen. It remains unknown whether PSA is enzymatically active and what is the physiologic role of PSA in nonprostatic tissues. It is speculated that PSA may be involved in the regulation of growth factors. Measuring PSA in breast cancer cytosol, breast-nipple aspirate fluid, and female serum may have potential clinical utilities, including breast cancer prognosis, breast cancer risk assessment, and evaluation of androgen excess. Further studies are needed to identify the exact function and regulation of PSA in nonprostatic tissues and to explore the clinical application of this protein. PMID:9126224

  12. Antigenic characterization of influenza viruses produced using synthetic DNA and novel backbones.

    PubMed

    Suphaphiphat, Pirada; Whittaker, Lynne; De Souza, Ivna; Daniels, Rodney S; Dormitzer, Philip R; McCauley, John W; Settembre, Ethan C

    2016-07-12

    The global system for manufacturing seasonal influenza vaccines has been developed to respond to the natural evolution of influenza viruses, but the problem of antigenic mismatch continues to be a challenge in certain years. In some years, mismatches arise naturally due to the antigenic drift of circulating viruses after vaccine strain selection has already been made. In other years, antigenic differences between the vaccine virus and circulating viruses are introduced as part of the current system, which relies on the use of egg-adapted isolates as a starting material for candidate vaccine viruses (CVVs). Improving the current process for making vaccine viruses can provide great value. We have previously established a synthetic approach for rapidly generating influenza viruses in a vaccine-approved Madin Darby canine kidney (MDCK) cell line using novel, high-growth backbones that increase virus rescue efficiency and antigen yield. This technology also has the potential to produce viruses that maintain antigenic similarity to the intended reference viruses, depending on the hemagglutinin (HA) and neuraminidase (NA) sequences used for gene synthesis. To demonstrate this utility, we generated a panel of synthetic viruses using HA and NA sequences from recent isolates and showed by hemagglutination inhibition (HI) tests that all synthetic viruses were antigenically-like their conventional egg- or cell-propagated reference strains and there was no impact of the novel backbones on antigenicity. This synthetic approach can be used for the efficient production of CVVs that may be more representative of circulating viruses and may be used for both egg- and cell-based vaccine manufacturing platforms. When combined with mammalian cell culture technology for antigen production, synthetic viruses generated using HA and NA sequences from a non-egg-adapted prototype can help to reduce the potential impact of antigenic differences between vaccine virus and circulating viruses on

  13. Immunogenic potential of latency associated antigens against Mycobacterium tuberculosis.

    PubMed

    Singh, Swati; Saraav, Iti; Sharma, Sadhna

    2014-02-01

    Tuberculosis remains a great health threat to the world among infectious diseases particularly with the advent of human immunodeficiency virus and emergence of drug resistant strains. In the light of the inconsistent efficacy imparted by the only currently available pre-exposure vaccine bacillus Calmette-Guerin BCG, the development of an improved TB vaccine is a very high international research priority. Vaccine candidates currently in clinical trials are also pre-exposure vaccines that aim to prevent active tuberculosis during an individual's lifetime. According to World Health Organization approximately a third of the world's population is latently infected with Mycobacterium tuberculosis. Dormancy or latency of Mycobacteria is associated with the formation of granuloma with poorly perfused interior leading to expression of genes which help them survive in this hostile environment. A group of about 50 genes belonging to the DosR regulon also known as latency antigens are expressed by Mycobacteria when they are persisting in the immuno-competent host. An understanding of the immunological effects produced by products of these latency induced genes may help in making a more potent vaccine. Incorporation of latency antigens into improved (live or subunit) vaccines may enhance the impact of these vaccines in which BCG priming can be followed by multisubunit protein boosting. These vaccines could act as post exposure vaccines for containment and prevention of latent TB activation. This heterologous boosting of BCG-primed immunity will be able to stimulate the known immune correlates of protective immunity against M. tuberculosis i.e. TH1 cells (CD4(+) and CD8(+) T cells) mediated immune responses with cytokines such as IFN-γ and TNF-α⋅ In our review we have analysed and compared the immunogenic potential of various latency-associated antigens of the DosR regulon in line with the current strategy of developing a recombinant post exposure booster vaccine. PMID

  14. Antigenic variation in African trypanosomes: the importance of chromosomal and nuclear context in VSG expression control

    PubMed Central

    Glover, Lucy; Hutchinson, Sebastian; Alsford, Sam; McCulloch, Richard; Field, Mark C; Horn, David

    2013-01-01

    African trypanosomes are lethal human and animal parasites that use antigenic variation for evasion of host adaptive immunity. To facilitate antigenic variation, trypanosomes dedicate approximately one third of their nuclear genome, including many minichromosomes, and possibly all sub-telomeres, to variant surface glycoprotein (VSG) genes and associated sequences. Antigenic variation requires transcription of a single VSG by RNA polymerase I (Pol-I), with silencing of other VSGs, and periodic switching of the expressed gene, typically via DNA recombination with duplicative translocation of a new VSG to the active site. Thus, telomeric location, epigenetic controls and monoallelic transcription by Pol-I at an extranucleolar site are prominent features of VSGs and their expression, with telomeres, chromatin structure and nuclear organization all making vitally important contributions to monoallelic VSG expression control and switching. We discuss VSG transcription, recombination and replication control within this chromosomal and sub-nuclear context. PMID:24047558

  15. Vaccinia Virus A35R Inhibits MHC Class II Antigen Presentation

    PubMed Central

    Rehm, Kristina E.; Connor, Ramsey F.; Jones, Gwendolyn J.B.; Yimbu, Kenneth; Roper, Rachel L.

    2009-01-01

    The Vaccinia virus gene A35R (Copenhagen designation) is highly conserved in mammalian-tropic poxviruses and is an important virulence factor, but its function was unknown. We show herein that A35 does not affect viral infectivity, apoptosis induction, or replication; however, we found that A35 significantly inhibited MHC class II-restricted antigen presentation, immune priming of T lymphocytes, and subsequent chemokine and cytokine synthesis. A35 localized to endosomes and reduced the amount of a model antigenic peptide displayed in the cleft of class II MHC. In addition, A35 decreased VV specific T cell responses in vivo. Thus, this is the first report identifying a function for the A35 protein in virulence as well as the first report identifying a VV gene that inhibits peptide antigen presentation. PMID:19954808

  16. The Immunologically Distinct O Antigens from Francisella tularensis Subspecies tularensis and Francisella novicida Are both Virulence Determinants and Protective Antigens▿

    PubMed Central

    Thomas, Rebecca M.; Titball, Richard W.; Oyston, Petra C. F.; Griffin, Kate; Waters, Emma; Hitchen, Paul G.; Michell, Stephen L.; Grice, I. Darren; Wilson, Jennifer C.; Prior, Joann L.

    2007-01-01

    We have determined the sequence of the gene cluster encoding the O antigen in Francisella novicida and compared it to the previously reported O-antigen cluster in Francisella tularensis subsp. tularensis. Immunization with purified lipopolysaccharide (LPS) from F. tularensis subsp. tularensis or F. novicida protected against challenge with Francisella tularensis subsp. holarctica and F. novicida, respectively. The LPS from F. tularensis subsp. tularensis did not confer protection against challenge with F. novicida, and the LPS from F. novicida did not confer protection against challenge with F. tularensis subsp. holarctica. Allelic replacement mutants of F. tularensis subsp. tularensis or F. novicida which failed to produce O antigen were attenuated, but exposure to these mutants did not induce a protective immune response. The O antigen of F. tularensis subsp. tularensis appeared to be important for intracellular survival whereas the O antigen of F. novicida appeared to be critical for serum resistance and less important for intracellular survival. PMID:17074846

  17. Designing Chimeric Antigen Receptors to Effectively and Safely Target Tumors

    PubMed Central

    Jensen, Michael C.; Riddell, Stanley R.

    2015-01-01

    The adoptive transfer of T cells engineered to express artificial chimeric antigen receptors (CARs) that target a tumor cell surface molecule has emerged as an exciting new approach for cancer immunotherapy. Clinical trials in patients with advanced B cell malignancies treated with CD19-specific CAR-modified T cells (CAR-T) have shown impressive antitumor efficacy, leading to optimism that this approach will be useful for treating common solid tumors. Because CAR-T cells recognize tumor cells independent of their expression of human leukocyte antigen (HLA) molecules, tumors that escape conventional T cells by downregulating HLA and/or mutating components of the antigen processing machinery can be eliminated. The ability to introduce or delete additional genes in T cells has the potential to provide therapeutic cell products with novel attributes that overcome impediments to immune mediated tumor elimination in immunosuppressive tumor microenvironments. This review will discuss recent concepts in the development of effective and safe synthetic CARs for adoptive T cell therapy (ACT). PMID:25621840

  18. The antigenic switching network of Plasmodium falciparum and its implications for the immuno-epidemiology of malaria

    PubMed Central

    Noble, Robert; Christodoulou, Zóe; Kyes, Sue; Pinches, Robert; Newbold, Chris I; Recker, Mario

    2013-01-01

    Antigenic variation in the human malaria parasite Plasmodium falciparum involves sequential and mutually exclusive expression of members of the var multi-gene family and appears to follow a non-random pattern. In this study, using a detailed in vitro gene transcription analysis of the culture-adapted HB3 strain of P. falciparum, we show that antigenic switching is governed by a global activation hierarchy favouring short and highly diverse genes in central chromosomal location. Longer and more conserved genes, which have previously been associated with severe infection in immunologically naive hosts, are rarely activated, however, implying an in vivo fitness advantage possibly through adhesion-dependent survival rates. We further show that a gene’s activation rate is positively associated sequence diversity, which could offer important new insights into the evolution and maintenance of antigenic diversity in P. falciparum malaria. DOI: http://dx.doi.org/10.7554/eLife.01074.001 PMID:24062941

  19. Diagnotic value of some Fasciola gigantica antigens.

    PubMed

    Shalaby, Said; El-Bahy, Mohammad; Hassan, Ali; Shalaby, Hatem; Gupta, Neelima

    2015-09-01

    The present study was aimed to select the specificity of antigens for Fasciola gigantica depending on its diagnostic utility and field applications. The tested antigens were coproantigen, excretory-secretory (ES) antigen and egg antigen. Coproantigen and Copro Hyperimmune serum were able to reflect the lowest level of cross-reaction with other tested F. gigantica antigens. By using SDS-PAGE, a structural homology was observed in F. gigantica ES and egg antigens. Intense cross reaction was observed between ES and egg antigens by ELISA technique even when there was no cross-reaction with coproantigen. The 27.6 kDa band proved to be the most specific in F. gigantica coproantigen and was different from the band at the same molecular weight by ES antigen. The results conclude that coproantigens show specific diagnostic ability for Fasciola and have low numbers of cross-reaction proteins reflecting its high specificity. Moreover, detection of coproantigen in faeces offers a new potential for diagnostics as compared to serum samples. This fact holds promise for a more accurate diagnostic technique in the near future for suspected Fasciola infection. PMID:26345056

  20. Antigenic composition of Litomosoides carini.

    PubMed

    Enayat, M S

    1976-07-01

    Three different phosphate buffered saline extracts of Litomosoides carini were prepared and examined by gel diffusion, immunoelectrophoresis and disc polyacrylamide gel electrophoresis using sera from infected cotton rats and antisera from hyperimmunized rabbits. Using disc polyacrylamide gel electrophoresis, up to 22 protein, 6 lipoprotein and 4 glycoprotein bands were identified. A minimum of 8 precipitin lines were detected by gel diffusion and a maximum of 11 precipitin arcs by immunoelectrophoresis when pooled rabbit antiserum was used. Using infected cotton rat sera, fewer number of precipitin lines and arcs were detected. Two precipitin arcs did not have a counterpart on examination against pooled rabbit antiserum. The importance of these two specific antigenic components for use in immunodiagnosis of human filariasis has been discussed. PMID:823514

  1. Novel mouse model for carcinoembryonic antigen-based therapy.

    PubMed

    Chan, Carlos H F; Stanners, Clifford P

    2004-06-01

    Many novel cancer therapies, including immunotherapy and gene therapy, are specifically targeted to tumor-associated molecules, among which carcinoembryonic antigen (CEA) represents a popular example. Discrepancies between preclinical experimental data in animal models and clinical outcome in terms of therapeutic response and toxicity, however, often arise. Preclinical testing can be compromised by the lack of CEA and other closely related human CEA family members in rodents, which lack analogous genes for most human CEA family members. Here, we report the construction of a transgenic mouse with a 187-kb human bacterial artificial chromosome (CEABAC) that contains part of the human CEA family gene cluster including complete human CEA (CEACAM5), CEACAM3, CEACAM6, and CEACAM7 genes. The spatiotemporal expression pattern of these genes in the CEABAC mice was found to be remarkably similar to that of humans. This novel mouse will ensure better assessment than previously utilized models for the preclinical testing of CEA-targeted therapies and perhaps allow the testing of CEACAM6, which is overexpressed in many solid tumors and leukemias, as a therapeutic target. Moreover, expression of CEA family genes in gastrointestinal, breast, hematopoietic, urogenital, and respiratory systems could facilitate other clinical applications, such as the development of therapeutic agents against Neisseria gonorrhoeae infections, which use CEA family members as major receptors. PMID:15194045

  2. Bacteriophage-mediated Glucosylation Can Modify Lipopolysaccharide O-Antigens Synthesized by an ATP-binding Cassette (ABC) Transporter-dependent Assembly Mechanism.

    PubMed

    Mann, Evan; Ovchinnikova, Olga G; King, Jerry D; Whitfield, Chris

    2015-10-16

    Lysogenic bacteriophages may encode enzymes that modify the structures of lipopolysaccharide O-antigen glycans, altering the structure of the bacteriophage receptor and resulting in serotype conversion. This can enhance virulence and has implications for antigenic diversity and vaccine development. Side chain glucosylation is a common modification strategy found in a number of bacterial species. To date, glucosylation has only been observed in O-antigens synthesized by Wzy-dependent pathways, one of the two most prevalent O-antigen synthesis systems. Here we exploited a heterologous system to study the glucosylation potential of a model O-antigen produced in an ATP-binding cassette (ABC) transporter-dependent system. Although O-antigen production is cryptic in Escherichia coli K-12, because of a mutation in the synthesis genes, it possesses a prophage glucosylation cluster, which modifies the GlcNAc residue in an α-l-Rha-(1→3)-d-GlcNAc motif found in the original O16 antigen. Raoultella terrigena ATCC 33257 produces an O-antigen possessing the same disaccharide motif, but its assembly uses an ABC transporter-dependent system. E. coli harboring the R. terrigena O-antigen biosynthesis genes produced an O-antigen displaying reduced reactivity toward antisera raised against the native R. terrigena repeat structure, indicative of an altered chemical structure. Structural determination using NMR revealed the addition of glucose side chains to the repeat units. O-antigen modification was dependent on a functional ABC transporter, consistent with modification in the periplasm, and was eliminated by deletion of the glucosylation genes from the E. coli chromosome, restoring native level antisera sensitivity and structure. There are therefore no intrinsic mechanistic barriers for bacteriophage-mediated O-antigen glucosylation in ABC transporter-dependent pathways. PMID:26330553

  3. Shared themes of antigenic variation and virulence in bacterial, protozoal, and fungal infections.

    PubMed Central

    Deitsch, K W; Moxon, E R; Wellems, T E

    1997-01-01

    Pathogenic microbes have evolved highly sophisticated mechanisms for colonizing host tissues and evading or deflecting assault by the immune response. The ability of these microbes to avoid clearance prolongs infection, thereby promoting their long-term survival within individual hosts and, through transmission, between hosts. Many pathogens are capable of extensive antigenic changes in the face of the multiple constitutive and dynamic components of host immune defenses. As a result, highly diverse populations that have widely different virulence properties can arise from a single infecting organism (clone). In this review, we consider the molecular and genetic features of antigenic variation and corresponding host-parasite interactions of different pathogenic bacterial, fungal, and protozoan microorganisms. The host and microbial molecules involved in these interactions often determine the adhesive, invasive, and antigenic properties of the infecting organisms and can dramatically affect the virulence and pathobiology of individual infections. Pathogens capable of such antigenic variation exhibit mechanisms of rapid mutability in confined chromosomal regions containing specialized genes designated contingency genes. The mechanisms of hypermutability of contingency genes are common to a variety of bacterial and eukaryotic pathogens and include promoter alterations, reading-frame shifts, gene conversion events, genomic rearrangements, and point mutations. PMID:9293182

  4. Posttranslational modification at the N terminus of the human adenovirus type 12 E1A 235R tumor antigen.

    PubMed Central

    Lucher, L A; Brackmann, K H; Symington, J S; Green, M

    1986-01-01

    The adenovirus E1A transforming region, which encodes immortalization, partial cell transformation, and gene activation functions, expresses two early mRNAs, 13S and 12S. Multiple-T antigen species with different electrophoretic mobilities are formed from each mRNA, presumably by unknown posttranslational modifications. The adenovirus type 12 (Ad12) 13S and 12S mRNAs encode E1A T antigens of 266 and 235 amino acid residues (266R and 235R), respectively. To study possible posttranslational processing at the N and C termini and to distinguish between the Ad12 266R and 235R T antigens, we prepared antibodies targeted to synthetic peptides encoded at the common C (peptide 204) and N (peptide 202) termini of the 266R and 235R T antigens and at the unique internal domain of the 266R T antigen (peptide 206). The specificity of each anti-peptide antibody was confirmed by immunoprecipitation of the 266R and 235R T antigens produced in Escherichia coli. Immunoprecipitation analysis of the E1A T antigens synthesized in Ad12-infected KB cells revealed the following. Antibody to the common C terminus recognized three T antigens with apparent Mrs of 43,000, 42,000, and 39,000 (43K, 42K, and 39K). All three forms were phosphorylated and were present in both the nucleus and the cytoplasm. The 43K and 42K T antigens were rapidly synthesized during a 10-min pulse with [35S]methionine in Ad12-infected cells. The 43K T antigen had a half-life of 20 min, the 42K T antigen had a longer half-life of about 40 min, and the 39K T antigen became the predominant E1A T antigen. Antibodies to the unique region immunoprecipitated the 43K T antigen but not the 42K and 39K T antigens. Antibody to the N terminus immunoprecipitated the 43K and 42K T antigens but not the 39K T antigen, suggesting that the 39K T antigen possessed a modified N terminus. Partial N-terminal amino acid sequence analysis showed that the 43K and 42K T antigens contain methionine at residues 1 and 5, as predicted from the

  5. CTdatabase: a knowledge-base of high-throughput and curated data on cancer-testis antigens.

    PubMed

    Almeida, Luiz Gonzaga; Sakabe, Noboru J; deOliveira, Alice R; Silva, Maria Cristina C; Mundstein, Alex S; Cohen, Tzeela; Chen, Yao-Tseng; Chua, Ramon; Gurung, Sita; Gnjatic, Sacha; Jungbluth, Achim A; Caballero, Otávia L; Bairoch, Amos; Kiesler, Eva; White, Sarah L; Simpson, Andrew J G; Old, Lloyd J; Camargo, Anamaria A; Vasconcelos, Ana Tereza R

    2009-01-01

    The potency of the immune response has still to be harnessed effectively to combat human cancers. However, the discovery of T-cell targets in melanomas and other tumors has raised the possibility that cancer vaccines can be used to induce a therapeutically effective immune response against cancer. The targets, cancer-testis (CT) antigens, are immunogenic proteins preferentially expressed in normal gametogenic tissues and different histological types of tumors. Therapeutic cancer vaccines directed against CT antigens are currently in late-stage clinical trials testing whether they can delay or prevent recurrence of lung cancer and melanoma following surgical removal of primary tumors. CT antigens constitute a large, but ill-defined, family of proteins that exhibit a remarkably restricted expression. Currently, there is a considerable amount of information about these proteins, but the data are scattered through the literature and in several bioinformatic databases. The database presented here, CTdatabase (http://www.cta.lncc.br), unifies this knowledge to facilitate both the mining of the existing deluge of data, and the identification of proteins alleged to be CT antigens, but that do not have their characteristic restricted expression pattern. CTdatabase is more than a repository of CT antigen data, since all the available information was carefully curated and annotated with most data being specifically processed for CT antigens and stored locally. Starting from a compilation of known CT antigens, CTdatabase provides basic information including gene names and aliases, RefSeq accession numbers, genomic location, known splicing variants, gene duplications and additional family members. Gene expression at the mRNA level in normal and tumor tissues has been collated from publicly available data obtained by several different technologies. Manually curated data related to mRNA and protein expression, and antigen-specific immune responses in cancer patients are also

  6. CTdatabase: a knowledge-base of high-throughput and curated data on cancer-testis antigens

    PubMed Central

    Almeida, Luiz Gonzaga; Sakabe, Noboru J.; deOliveira, Alice R.; Silva, Maria Cristina C.; Mundstein, Alex S.; Cohen, Tzeela; Chen, Yao-Tseng; Chua, Ramon; Gurung, Sita; Gnjatic, Sacha; Jungbluth, Achim A.; Caballero, Otávia L.; Bairoch, Amos; Kiesler, Eva; White, Sarah L.; Simpson, Andrew J. G.; Old, Lloyd J.; Camargo, Anamaria A.; Vasconcelos, Ana Tereza R.

    2009-01-01

    The potency of the immune response has still to be harnessed effectively to combat human cancers. However, the discovery of T-cell targets in melanomas and other tumors has raised the possibility that cancer vaccines can be used to induce a therapeutically effective immune response against cancer. The targets, cancer-testis (CT) antigens, are immunogenic proteins preferentially expressed in normal gametogenic tissues and different histological types of tumors. Therapeutic cancer vaccines directed against CT antigens are currently in late-stage clinical trials testing whether they can delay or prevent recurrence of lung cancer and melanoma following surgical removal of primary tumors. CT antigens constitute a large, but ill-defined, family of proteins that exhibit a remarkably restricted expression. Currently, there is a considerable amount of information about these proteins, but the data are scattered through the literature and in several bioinformatic databases. The database presented here, CTdatabase (http://www.cta.lncc.br), unifies this knowledge to facilitate both the mining of the existing deluge of data, and the identification of proteins alleged to be CT antigens, but that do not have their characteristic restricted expression pattern. CTdatabase is more than a repository of CT antigen data, since all the available information was carefully curated and annotated with most data being specifically processed for CT antigens and stored locally. Starting from a compilation of known CT antigens, CTdatabase provides basic information including gene names and aliases, RefSeq accession numbers, genomic location, known splicing variants, gene duplications and additional family members. Gene expression at the mRNA level in normal and tumor tissues has been collated from publicly available data obtained by several different technologies. Manually curated data related to mRNA and protein expression, and antigen-specific immune responses in cancer patients are also

  7. Antigen-induced suppression of the in vitro lymphocyte response to different antigens and mitogens

    PubMed Central

    Möller, Göran; Kashiwagi, Noboru

    1972-01-01

    Certain concentrations of antigen stimulated DNA synthesis in sensitized human lymphocytes cultivated in vitro, higher and lower concentrations being less stimulatory. The simultaneous addition of two antigens in low concentrations to the same cells caused an additive response. The decreased response to a high antigen dose did not affect the capacity of the cells to respond to the simultaneous addition of another antigen, as determined at the population level as well as at the cellular level by autoradiography. Presumably specific immunological paralysis was induced by high antigen doses. Addition of low antigen doses for 1–3 days to human sensitized lymphocytes cultivated in vitro resulted in decreased DNA synthesis as a response to the same antigen added in an optimal dose. Suppression of DNA synthesis was not caused by induction of tolerance or antibody suppression, because the cells also failed to respond to an unrelated antigen and to non-specific mitogens, such as PHA and ALS. Most likely the suppressed response after antigen pretreatment represents a phenomenon analogous to antigenic competition, although this term is not appropriate, since there need not be competition between antigens for a detectable effect. No soluble mediators of suppression could be demonstrated in the supernatant of suppressed cultures. PMID:5026855

  8. Calcium-dependent antigen binding as a novel modality for antibody recycling by endosomal antigen dissociation

    PubMed Central

    Hironiwa, N; Ishii, S; Kadono, S; Iwayanagi, Y; Mimoto, F; Habu, K; Igawa, T; Hattori, K

    2016-01-01

    The pH-dependent antigen binding antibody, termed a recycling antibody, has recently been reported as an attractive type of second-generation engineered therapeutic antibody. A recycling antibody can dissociate antigen in the acidic endosome, and thus bind to its antigen multiple times. As a consequence, a recycling antibody can neutralize large amounts of antigen in plasma. Because this approach relies on histidine residues to achieve pH-dependent antigen binding, which could limit the epitopes that can be targeted and affect the rate of antigen dissociation in the endosome, we explored an alternative approach for generating recycling antibodies. Since calcium ion concentration is known to be lower in endosome than in plasma, we hypothesized that an antibody with antigen-binding properties that are calcium-dependent could be used as recycling antibody. Here, we report a novel anti-interleukin-6 receptor (IL-6R) antibody, identified from a phage library that binds to IL-6R only in the presence of a calcium ion. Thermal dynamics and a crystal structure study revealed that the calcium ion binds to the heavy chain CDR3 region (HCDR3), which changes and possibly stabilizes the structure of HCDR3 to make it bind to antigen calcium dependently (PDB 5AZE). In vitro and in vivo studies confirmed that this calcium-dependent antigen-binding antibody can dissociate its antigen in the endosome and accelerate antigen clearance from plasma, making it a novel approach for generating recycling antibody. PMID:26496237

  9. Tiny T antigen: an autonomous polyomavirus T antigen amino-terminal domain.

    PubMed Central

    Riley, M I; Yoo, W; Mda, N Y; Folk, W R

    1997-01-01

    Three mRNAs from the murine polyomavirus early region encode the three well-characterized tumor antigens. We report the existence of a fourth alternatively spliced mRNA which encodes a fourth tumor antigen, tiny T antigen, which comprises the amino-terminal domain common to all of the T antigens but is extended by six unique amino acid residues. The amount of tiny T antigen in infected cells is small because of its short half-life. Tiny T antigen stimulates the ATPase activity of Hsc70, most likely because of its DnaJ-like motif. The common amino-terminal domain may interface with chaperone complexes to assist the T antigens in carrying out their diverse functions of replication, transcription, and transformation in the appropriate cellular compartments. PMID:9223500

  10. Human immunodeficiency virus type 1 Nef does not alter T-cell sensitivity to antigen-specific stimulation.

    PubMed Central

    Page, K A; van Schooten, W C; Feinberg, M B

    1997-01-01

    We have developed an in vitro model to study the influence that human immunodeficiency virus type 1 (HIV-1) may have on the ability of T cells to respond to antigenic challenge. We have examined consequences of HIV-1 gene expression on T-cell activation in antigen-dependent T cells that have stably integrated copies of replication-defective proviral HIV-1. Virus production by HIV-infected, antigen-dependent T cells was induced in response to antigenic stimulation and then decreased as infected cells returned to a state of quiescence. Contrary to the predictions of models proposing that Nef alters signal transduction pathways in T lymphocytes and thereby alters cellular activation, Nef expression in antigen-dependent T-cell clones did not influence their proliferative responses to low or intermediate concentrations of antigen and did not affect other measures of T-cell activation, such as induction of interleukin 2 receptor alpha-chain expression and cytokine production. In addition, we found no evidence for alteration of T-cell responsiveness to antigen by the gag, pol, vif, tat, or rev gene of HIV-1. PMID:9094653

  11. Erythrocyte Membrane Antigen Frequencies in Patients with Type II Congenital Smell Loss

    PubMed Central

    Stateman, William A.; Henkin, Robert I.; Knöppel, Alexandra; Flegel, Willy A.

    2014-01-01

    OBJECTIVE The objective of this study was to determine whether there are genetic factors associated with Type II congenital smell loss. STUDY DESIGN The expression frequencies of 16 erythrocyte antigens among patients with Type II congenital smell loss were determined and compared to those of a large control group. METHODS Blood samples were obtained from 99 patients with Type II congenital smell loss. Presence of the erythrocyte surface antigens A, B, M, N, S, s, Fya, Fyb, D, C, c, E, e, K, Jka, and Jkb was analyzed by blood group serology. Comparisons of expression frequencies of these antigens were made between the patients and a large control group. RESULTS Patients tested for the Duffy b antigen (Fyb haplotype) exhibited a statistically significant 11% decrease in expression frequency compared to the controls. There were no significant differences between patients and controls in the expression frequencies for all other erythrocyte antigens (A, B, M, N, S, s, Fya, D, C, c, E, e, K, Jka, or Jkb). CONCLUSIONS These findings describe the presence of a previously unrevealed genetic tendency among patients with Type II congenital smell loss related to erythrocyte surface antigen expression. The deviation in expression rate of Duffy b suggests a target gene and chromosome region in which future research into this form of congenital smell loss may reveal a more specific genetic basis for Type II congenital smell loss. PMID:25456515

  12. A Mutant Library Approach to Identify Improved Meningococcal Factor H Binding Protein Vaccine Antigens

    PubMed Central

    Konar, Monica; Rossi, Raffaella; Walter, Helen; Pajon, Rolando; Beernink, Peter T.

    2015-01-01

    Factor H binding protein (FHbp) is a virulence factor used by meningococci to evade the host complement system. FHbp elicits bactericidal antibodies in humans and is part of two recently licensed vaccines. Using human complement Factor H (FH) transgenic mice, we previously showed that binding of FH decreased the protective antibody responses to FHbp vaccination. Therefore, in the present study we devised a library-based method to identify mutant FHbp antigens with very low binding of FH. Using an FHbp sequence variant in one of the two licensed vaccines, we displayed an error-prone PCR mutant FHbp library on the surface of Escherichia coli. We used fluorescence-activated cell sorting to isolate FHbp mutants with very low binding of human FH and preserved binding of control anti-FHbp monoclonal antibodies. We sequenced the gene encoding FHbp from selected clones and introduced the mutations into a soluble FHbp construct. Using this approach, we identified several new mutant FHbp vaccine antigens that had very low binding of FH as measured by ELISA and surface plasmon resonance. The new mutant FHbp antigens elicited protective antibody responses in human FH transgenic mice that were up to 20-fold higher than those elicited by the wild-type FHbp antigen. This approach offers the potential to discover mutant antigens that might not be predictable even with protein structural information and potentially can be applied to other microbial vaccine antigens that bind host proteins. PMID:26057742

  13. Direct evidence for cytotoxicity associated with expression of hepatitis delta virus antigen.

    PubMed

    Cole, S M; Gowans, E J; Macnaughton, T B; Hall, P D; Burrell, C J

    1991-05-01

    It has been postulated that hepatocyte injury resulting from infection with hepatitis D virus may be caused by a direct virus cytotoxicity in contrast to immune-mediated injury associated with hepatitis B virus. We have transfected HeLa and HepG2 continuous cell lines with a recombinant plasmid containing the hepatitis D antigen gene under the inducible control of the human metallothionein promoter. The addition of zinc to the cell culture medium then led to the expression of hepatitis D antigen associated with, in the short term, a significant reduction in the rate of RNA but not DNA synthesis and, in the longer term, cell death. The necrotic cells had pyknotic nuclei and shrunken eosinophilic cytoplasm; these necrotic cells resembled the apoptotic bodies seen in hepatitis D virus-related hepatitis. The level of hepatitis D antigen in individual cells that produced these changes was similar to the level of hepatitis D antigen in hepatocytes from a chimpanzee with acute hepatitis D virus infection. We conclude that the expression of hepatitis D antigen resulted in significant cytotoxic changes in these cells, providing strong support for the view that hepatitis D antigen may be specifically cytotoxic to infected hepatocytes in vivo. PMID:1709411

  14. A Mutant Library Approach to Identify Improved Meningococcal Factor H Binding Protein Vaccine Antigens.

    PubMed

    Konar, Monica; Rossi, Raffaella; Walter, Helen; Pajon, Rolando; Beernink, Peter T

    2015-01-01

    Factor H binding protein (FHbp) is a virulence factor used by meningococci to evade the host complement system. FHbp elicits bactericidal antibodies in humans and is part of two recently licensed vaccines. Using human complement Factor H (FH) transgenic mice, we previously showed that binding of FH decreased the protective antibody responses to FHbp vaccination. Therefore, in the present study we devised a library-based method to identify mutant FHbp antigens with very low binding of FH. Using an FHbp sequence variant in one of the two licensed vaccines, we displayed an error-prone PCR mutant FHbp library on the surface of Escherichia coli. We used fluorescence-activated cell sorting to isolate FHbp mutants with very low binding of human FH and preserved binding of control anti-FHbp monoclonal antibodies. We sequenced the gene encoding FHbp from selected clones and introduced the mutations into a soluble FHbp construct. Using this approach, we identified several new mutant FHbp vaccine antigens that had very low binding of FH as measured by ELISA and surface plasmon resonance. The new mutant FHbp antigens elicited protective antibody responses in human FH transgenic mice that were up to 20-fold higher than those elicited by the wild-type FHbp antigen. This approach offers the potential to discover mutant antigens that might not be predictable even with protein structural information and potentially can be applied to other microbial vaccine antigens that bind host proteins. PMID:26057742

  15. Antigenic variation: Molecular and genetic mechanisms of relapsing disease

    SciTech Connect

    Cruse, J.M.; Lewis, R.E.

    1987-01-01

    This book contains 10 chapters. They are: Contemporary Concepts of Antigenic Variation; Antigenic Variation in the Influenza Viruses; Mechanisms of Escape of Visna Lentiviruses from Immunological Control; A Review of Antigenic Variation by the Equine Infectious Anemia Virus; Biologic and Molecular Variations in AIDS Retrovirus Isolates; Rabies Virus Infection: Genetic Mutations and the Impact on Viral Pathogenicity and Immunity; Immunobiology of Relapsing Fever; Antigenic Variation in African Trypanosomes; Antigenic Variation and Antigenic Diversity in Malaria; and Mechanisms of Immune Evasion in Schistosomiasis.

  16. Limited Antigenic Diversity in Contemporary H7 Avian-Origin Influenza A Viruses from North America

    PubMed Central

    Xu, Yifei; Bailey, Elizabeth; Spackman, Erica; Li, Tao; Wang, Hui; Long, Li-Ping; Baroch, John A.; Cunningham, Fred L.; Lin, Xiaoxu; Jarman, Richard G.; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    Subtype H7 avian–origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Here we antigenically and genetically characterized 93 AIV isolates from North America (85 from migratory waterfowl [1976–2010], 7 from domestic poultry [1971–2012], and 1 from a seal [1980]). The hemagglutinin gene of these H7 viruses are separated from those from Eurasia. Gradual accumulation of nucleotide and amino acid substitutions was observed in the hemagglutinin of H7 AIVs from waterfowl and domestic poultry. Genotype characterization suggested that H7 AIVs in wild birds form diverse and transient internal gene constellations. Serologic analyses showed that the 93 isolates cross-reacted with each other to different extents. Antigenic cartography showed that the average antigenic distance among them was 1.14 units (standard deviation [SD], 0.57 unit) and that antigenic diversity among the H7 isolates we tested was limited. Our results suggest that the continuous genetic evolution has not led to significant antigenic diversity for H7 AIVs from North America. These findings add to our understanding of the natural history of IAVs and will inform public health decision-making regarding the threat these viruses pose to humans and poultry. PMID:26858078

  17. Inhibition of MHC class I-restricted antigen presentation by gamma 2-herpesviruses.

    PubMed

    Stevenson, P G; Efstathiou, S; Doherty, P C; Lehner, P J

    2000-07-18

    The gamma-herpesviruses, in contrast to the alpha- and beta-herpesviruses, are not known to inhibit antigen presentation to CD8(+) cytotoxic T lymphocytes (CTLs) during lytic cycle replication. However, murine gamma-herpesvirus 68 causes a chronic lytic infection in CD4(+) T cell-deficient mice despite the persistence of a substantial CTL response, suggesting that CTL evasion occurs. Here we show that, distinct from host protein synthesis shutoff, gamma-herpesvirus 68 down-regulates surface MHC class I expression on lytically infected fibroblasts and inhibits their recognition by antigen-specific CTLs. The viral K3 gene, encoding a zinc-finger-containing protein, dramatically reduced the half-life of nascent class I molecules and the level of surface MHC class I expression and was by itself sufficient to block antigen presentation. The homologous K3 and K5 genes of the related Kaposi's sarcoma-associated virus also inhibited antigen presentation and decreased cell surface expression of HLA class I antigens. Thus it appears that an immune evasion strategy shared by at least two gamma-herpesviruses allows continued lytic infection in the face of strong CTL immunity. PMID:10890918

  18. Limited Antigenic Diversity in Contemporary H7 Avian-Origin Influenza A Viruses from North America.

    PubMed

    Xu, Yifei; Bailey, Elizabeth; Spackman, Erica; Li, Tao; Wang, Hui; Long, Li-Ping; Baroch, John A; Cunningham, Fred L; Lin, Xiaoxu; Jarman, Richard G; DeLiberto, Thomas J; Wan, Xiu-Feng

    2016-01-01

    Subtype H7 avian-origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Here we antigenically and genetically characterized 93 AIV isolates from North America (85 from migratory waterfowl [1976-2010], 7 from domestic poultry [1971-2012], and 1 from a seal [1980]). The hemagglutinin gene of these H7 viruses are separated from those from Eurasia. Gradual accumulation of nucleotide and amino acid substitutions was observed in the hemagglutinin of H7 AIVs from waterfowl and domestic poultry. Genotype characterization suggested that H7 AIVs in wild birds form diverse and transient internal gene constellations. Serologic analyses showed that the 93 isolates cross-reacted with each other to different extents. Antigenic cartography showed that the average antigenic distance among them was 1.14 units (standard deviation [SD], 0.57 unit) and that antigenic diversity among the H7 isolates we tested was limited. Our results suggest that the continuous genetic evolution has not led to significant antigenic diversity for H7 AIVs from North America. These findings add to our understanding of the natural history of IAVs and will inform public health decision-making regarding the threat these viruses pose to humans and poultry. PMID:26858078

  19. Induction of antigen-specific regulatory T cells in the liver-draining celiac lymph node following oral antigen administration.

    PubMed

    Hultkrantz, Susanne; Ostman, Sofia; Telemo, Esbjörn

    2005-11-01

    Regulatory T cells are induced by oral administration of an antigen, but the physiological requirements and localization of the inductive sites are largely unknown. Using an adoptive transfer system of cells transgenic for ovalbumin T-cell receptor (OVA TCR tg), we found that antigen-specific CD4+ T cells were activated in the liver-draining celiac lymph node (CLN) shortly after ovalbumin feeding, and that a significantly higher proportion of the T cells in the CLN developed into the putative regulatory phenotype [co-expressing CD25 with the glucocortico-induced tumour necrosis factor (TNF) receptor family related gene (GITR), cytotoxic T-lymphocyte antigen (CTLA)-4 and CD103] than in Peyer's patches, the mesenteric and peripheral lymph nodes and the spleen. In addition, a particularly high level of expression of CD103 on the OVA-specific T cells in the CLN may favour homing to the epithelium of the intestine. While equally suppressive, OVA tg T cells isolated from the CLN of OVA-fed DO11.10 mice were less dependent on transforming growth factor (TGF)-beta for suppression than cells isolated from the peripheral and mesenteric lymph nodes, which indicates the involvement of an additional suppressive mechanism. The expression of FoxP3 was not up-regulated in any of the lymph node compartments studied. Our phenotypic and functional findings suggest that the induction of regulatory T cells in the CLN may be relevant in the control of the immune response to dietary antigens. PMID:16236126

  20. Non-antigenic and antigenic interventions in type 1 diabetes

    PubMed Central

    Rydén, Anna KE; Wesley, Johnna D; Coppieters, Ken T; Von Herrath, Matthias G

    2014-01-01

    Type 1 diabetes (T1D) results from autoimmune destruction of the pancreatic β-cells. Current T1D therapies are exclusively focused on regulating glycemia rather than the underlying immune response. A handful of trials have sought to alter the clinical course of T1D using various broad immune-suppressors, e.g., cyclosporine A and azathioprine.1–3 The effect on β-cell preservation was significant, however, these therapies were associated with unacceptable side-effects. In contrast, more recent immunomodulators, such as anti-CD3 and antigenic therapies such as DiaPep277, provide a more targeted immunomodulation and have been generally well-tolerated and safe; however, as a monotherapy there appear to be limitations in terms of therapeutic benefit. Therefore, we argue that this new generation of immune-modifying agents will likely work best as part of a combination therapy. This review will summarize current immune-modulating therapies under investigation and discuss how to move the field of immunotherapy in T1D forward. PMID:24165565

  1. The Use of High-Throughput DNA Sequencing in the Investigation of Antigenic Variation: Application to Neisseria Species

    PubMed Central

    Davies, John K.; Harrison, Paul F.; Lin, Ya-Hsun; Bartley, Stephanie; Khoo, Chen Ai; Seemann, Torsten; Ryan, Catherine S.; Kahler, Charlene M.; Hill, Stuart A.

    2014-01-01

    Antigenic variation occurs in a broad range of species. This process resembles gene conversion in that variant DNA is unidirectionally transferred from partial gene copies (or silent loci) into an expression locus. Previous studies of antigenic variation have involved the amplification and sequencing of individual genes from hundreds of colonies. Using the pilE gene from Neisseria gonorrhoeae we have demonstrated that it is possible to use PCR amplification, followed by high-throughput DNA sequencing and a novel assembly process, to detect individual antigenic variation events. The ability to detect these events was much greater than has previously been possible. In N. gonorrhoeae most silent loci contain multiple partial gene copies. Here we show that there is a bias towards using the copy at the 3′ end of the silent loci (copy 1) as the donor sequence. The pilE gene of N. gonorrhoeae and some strains of Neisseria meningitidis encode class I pilin, but strains of N. meningitidis from clonal complexes 8 and 11 encode a class II pilin. We have confirmed that the class II pili of meningococcal strain FAM18 (clonal complex 11) are non-variable, and this is also true for the class II pili of strain NMB from clonal complex 8. In addition when a gene encoding class I pilin was moved into the meningococcal strain NMB background there was no evidence of antigenic variation. Finally we investigated several members of the opa gene family of N. gonorrhoeae, where it has been suggested that limited variation occurs. Variation was detected in the opaK gene that is located close to pilE, but not at the opaJ gene located elsewhere on the genome. The approach described here promises to dramatically improve studies of the extent and nature of antigenic variation systems in a variety of species. PMID:24466206

  2. Further characterization of filarial antigens by SDS polyacrylamide gel electrophoresis

    PubMed Central

    Dissanayake, S.; Galahitiyawa, S. C.; Ismail, M. M.

    1983-01-01

    SDS (sodium dodecyl sulfate)-polyacrylamide gel electrophoresis of an antigen isolated from sera of Wuchereria bancrofti-infected patients and Setaria digitata antigen SD2-4 is reported. Both antigens showed carbohydrate (glycoprotein) staining. The W. bancrofti antigen had an apparent relative molecular mass of 35 000 while the S. digitata antigen SD2-4 migrated at the marker dye position on SDS-polyacrylamide gel electrophoresis. SDS treatment of these antigens did not abolish the precipitation reaction with antibody. In the case of W. bancrofti antigen, SDS treatment probably exposed hitherto hidden antigen epitopes. PMID:6354508

  3. A new gene in A. rubens: A sea star Ig kappa gene.

    PubMed

    Vincent, Nadine; Osteras, Magne; Otten, Patricia; Leclerc, Michel

    2014-12-01

    The sea star Asterias rubens reacts specifically to the antigen:HRP (horse-radish peroxydase) and produces an antibody anti-HRP. We previously identified a candidate Ig kappa gene corresponding to this manuscript. We show now the gene referred to as: "sea star Ig kappa gene in its specificity". PMID:25606415

  4. Antigen-specific tolerogenic and immunomodulatory strategies for the treatment of autoimmune arthritis

    PubMed Central

    Satpute, Shailesh R.; Durai, Malarvizhi; Moudgil, Kamal D.

    2008-01-01

    Objectives To review various antigen-specific tolerogenic and immunomodulatory approaches for arthritis in animal models and patients in regard to their efficacy, mechanisms of action and limitations. Methods We reviewed the published literature in Medline (PubMed) on the induction of antigen-specific tolerance and its effect on autoimmune arthritis, as well as the recent work on B cell-mediated tolerance from our laboratory. The prominent key words used in different combinations included arthritis, autoimmunity, immunotherapy, innate immunity, tolerance, treatment, and rheumatoid arthritis (RA). Although this search spanned the years 1975 to 2007, the majority of the short-listed articles belonged to the period 1990 to 2007. The relevant primary as well as cross-referenced articles were then collected from links within PubMed and reviewed. Results Antigen-specific tolerance has been successful in the prevention and/or treatment of arthritis in animal models. The administration of soluble native antigen or an altered peptide ligand intravenously, orally, or nasally, and the delivery of the DNA encoding a particular antigen by gene therapy have been the mainstay of immunomodulation. Recently, the methods for in vitro-expansion of CD4+CD25+ regulatory T cells have been optimized. Furthermore, interleukin-17 has emerged as a promising new therapeutic target in arthritis. However, in RA patients, non-antigen-specific therapeutic approaches have been much more successful than antigen-specific tolerogenic regimens. Conclusion An antigen-specific treatment against autoimmune arthritis is still elusive. However, insights into newly emerging mechanisms of disease pathogenesis provide hope for the development of effective and safe immunotherapeutic strategies in the near future. PMID:18177689

  5. Characterization of the O-antigen Polymerase (Wzy) of Francisella tularensis*

    PubMed Central

    Kim, Tae-Hyun; Sebastian, Shite; Pinkham, Jessica T.; Ross, Robin A.; Blalock, LeeAnn T.; Kasper, Dennis L.

    2010-01-01

    The O-antigen polymerase of Gram-negative bacteria has been difficult to characterize. Herein we report the biochemical and functional characterization of the protein product (Wzy) of the gene annotated as the putative O-antigen polymerase, which is located in the O-antigen biosynthetic locus of Francisella tularensis. In silico analysis (homology searching, hydropathy plotting, and codon usage assessment) strongly suggested that Wzy is an O-antigen polymerase whose function is to catalyze the addition of newly synthesized O-antigen repeating units to a glycolipid consisting of lipid A, inner core polysaccharide, and one repeating unit of the O-polysaccharide (O-PS). To characterize the function of the Wzy protein, a non-polar deletion mutant of wzy was generated by allelic replacement, and the banding pattern of O-PS was observed by immunoblot analysis of whole-cell lysates obtained by SDS-PAGE and stained with an O-PS-specific monoclonal antibody. These immunoblot analyses showed that O-PS of the wzy mutant expresses only one repeating unit of O-antigen. Further biochemical characterization of the subcellular fractions of the wzy mutant demonstrated that (as is characteristic of O-antigen polymerase mutants) the low molecular weight O-antigen accumulates in the periplasm of the mutant. Site-directed mutagenesis based on protein homology and topology, which was carried out to locate a catalytic residue of the protein, showed that modification of specific residues (Gly176, Asp177, Gly323, and Tyr324) leads to a loss of O-PS polymerization. Topology models indicate that these amino acids most likely lie in close proximity on the bacterial surface. PMID:20605777

  6. Genetic variability of antigen B among Echinococcus granulosus Egyptian isolates.

    PubMed

    Tawfeek, Gihan M; Elwakil, Hala S; Awad, Nabil S; El-Hoseiny, Laila; Thabet, Hala S; Sarhan, Rania M; Darweesh, Samar K; Anwar, Wagida A

    2009-09-01

    Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively. PMID:19724699

  7. Cloning, heterologous expression and antigenicity of a schistosome cercarial protease.

    PubMed

    Price, H P; Doenhoff, M J; Sayers, J R

    1997-05-01

    A gene coding for the 30 kDa Schistosoma mansoni cercarial protease was amplified using the polymerase chain reaction (PCR) from genomic DNA templates. Cloning and sequencing of several independent PCR clones revealed the presence of an intron additional to the one described in the original cloning of the gene. The 3 exons were cloned into expression vectors so that they could be expressed as separate glutathione-S-transferase (GST) translational fusions. Recombinant bacteria carrying these expression plasmids expressed the fusion proteins at high levels. Western blotting of bacterial lysates with sera raised against the native S. mansoni cercarial protease showed that all 3 exons were recognized. Thus we have produced recombinant bacteria capable of providing large amounts of an S. mansoni antigen for immunological studies and evaluation as a candidate vaccine. PMID:9149415

  8. Genetic Variability of Antigen B among Echinococcus granulosus Egyptian Isolates

    PubMed Central

    Tawfeek, Gihan M.; Awad, Nabil S.; El-Hoseiny, Laila; Thabet, Hala S.; Sarhan, Rania M.; Darweesh, Samar K.; Anwar, Wagida A.

    2009-01-01

    Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively. PMID:19724699

  9. Cyclosporine inhibits macrophage-mediated antigen presentation

    SciTech Connect

    Ziegler, H.K.; Palay, D.; Wentworth, P.; Cluff, C.

    1986-03-01

    The influence of cyclosporine on antigen-specific, macrophage-dependent T cell activation was analyzed in vitro. Murine T cell activation by antigens derived from Listeria monocytogenes was monitored by the production of interleukin-2. Pretreatment (2 hrs., 37/sup 0/C) of macrophages with cyclosporine resulted in a population of macrophages with a markedly diminished capacity to support the activation of T lymphocytes. When cyclosporine-pretreated macrophages were added to cultures of antigen and untreated T cells, the dose of cyclosporine which produced 50% inhibition was 1.5 ..mu..g/ml. Appropriate control experiments indicated that cyclosporine was indeed inhibiting at the macrophage level. The addition of interleukin-1 or indomethacin to the cultures did not alter the inhibitory effect of cyclosporine. Under conditions which produced >90% inhibition of antigen presentation, macrophage surface Ia expression was not altered, and the uptake and catabolism of radiolabelled antigen was normal. Thus, cyclosporine inhibits antigen presentation by a mechanism which appears unrelated to changes in Il-1 elaboration, prostaglandin production, Ia expression, or antigen uptake and catabolism.

  10. Antigenic and molecular characterization of bat rabies virus in Europe.

    PubMed

    Bourhy, H; Kissi, B; Lafon, M; Sacramento, D; Tordo, N

    1992-09-01

    The predominant role of Eptesicus serotinus in the epizootic of bat rabies in Europe was further outlined by the first isolation of the rabies virus from this species in France. The distribution of the virus was studied in naturally infected E. serotinus bats at the time of death and suggested that the papillae of the tongue and the respiratory mucosa may play a role in virus production and excretion. The analysis of 501 French rabies virus isolates from various animal species by antinucleocapsid monoclonal antibodies indicated that transmission of the disease from bats to terrestrial animals is unlikely. The antigenic profile of two isolates from French bats corresponded to that of European bat lyssavirus type 1 (EBL1). Comparisons of 12 different isolates from bats with antinucleocapsid and antiglycoprotein monoclonal antibodies and by direct sequencing of the polymerase chain reaction amplification product of the N gene indicated that EBL1, EBL2, Duvenhage virus (serotype 4 of lyssavirus), and the European fox rabies virus (serotype 1) are phylogenetically distant. They formed four tight genetic clusters named genotypes. EBL1 was shown to be antigenically and genetically more closely related to Duvenhage virus than to EBL2. We propose that EBL1 and EBL2 constitute two distinct genotypes which further serologic characterization will probably classify as new serotypes. We also report a simple method for the rapid characterization of EBL based on the digestion of the polymerase chain reaction product of the N gene by three restriction endonucleases. PMID:1401009

  11. Antigen clasping by two antigen-binding sites of an exceptionally specific antibody for histone methylation

    PubMed Central

    Hattori, Takamitsu; Lai, Darson; Dementieva, Irina S.; Montaño, Sherwin P.; Kurosawa, Kohei; Zheng, Yupeng; Akin, Louesa R.; Świst-Rosowska, Kalina M.; Grzybowski, Adrian T.; Koide, Akiko; Krajewski, Krzysztof; Strahl, Brian D.; Kelleher, Neil L.; Ruthenburg, Alexander J.; Koide, Shohei

    2016-01-01

    Antibodies have a well-established modular architecture wherein the antigen-binding site residing in the antigen-binding fragment (Fab or Fv) is an autonomous and complete unit for antigen recognition. Here, we describe antibodies departing from this paradigm. We developed recombinant antibodies to trimethylated lysine residues on histone H3, important epigenetic marks and challenging targets for molecular recognition. Quantitative characterization demonstrated their exquisite specificity and high affinity, and they performed well in common epigenetics applications. Surprisingly, crystal structures and biophysical analyses revealed that two antigen-binding sites of these antibodies form a head-to-head dimer and cooperatively recognize the antigen in the dimer interface. This “antigen clasping” produced an expansive interface where trimethylated Lys bound to an unusually extensive aromatic cage in one Fab and the histone N terminus to a pocket in the other, thereby rationalizing the high specificity. A long-neck antibody format with a long linker between the antigen-binding module and the Fc region facilitated antigen clasping and achieved both high specificity and high potency. Antigen clasping substantially expands the paradigm of antibody–antigen recognition and suggests a strategy for developing extremely specific antibodies. PMID:26862167

  12. Humoral immunity to human breast cancer: antigen definition and quantitative analysis of mRNA expression.

    PubMed

    Scanlan, M J; Gout, I; Gordon, C M; Williamson, B; Stockert, E; Gure, A O; Jäger, D; Chen, Y T; Mackay, A; O'Hare, M J; Old, L J

    2001-03-30

    The ability of the immune system to recognize structurally altered, amplified or aberrantly expressed proteins can be used to identify molecules of etiologic relevance to cancer and to define targets for cancer immunotherapy. In the current study, ninety-four distinct antigens reactive with serum IgG from breast cancer patients were identified by immunoscreening breast cancer-derived cDNA expression libraries (SEREX). A serological profile was generated for each antigen on the basis of reactivity with allogeneic sera from normal individuals and cancer patients, and mRNA expression profiles for coding sequences were assembled based upon the tissue distribution of expressed sequence tags, Northern blots and real-time RT-PCR. Forty antigens reacted exclusively with sera from cancer patients. These included well-characterized tumor antigens, e.g. MAGE-3, MAGE-6, NY-ESO-1, Her2neu and p53, as well as newly-defined breast cancer antigens, e.g. kinesin 2, TATA element modulatory factor 1, tumor protein D52 and MAGE D, and novel gene products, e.g. NY-BR-62, NY-BR-75, NY-BR-85, and NY-BR-96. With regard to expression profiles, two of the novel gene products, NY-BR-62 and NY-BR-85, were characterized by a high level of testicular mRNA expression, and were overexpressed in 60% and 90% of breast cancers, respectively. In addition, mRNA encoding tumor protein D52 was overexpressed in 60% of breast cancer specimens, while transcripts encoding SNT-1 signal adaptor protein were downregulated in 70% of these cases. This study adds to the growing list of breast cancer antigens defined by SEREX and to the ultimate objective of identifying the complete repertoire of immunogenic gene products in human cancer (the cancer immunome). PMID:12747765

  13. Novel methods for expression of foreign antigens in live vector vaccines

    PubMed Central

    Wang, Jin Yuan; Harley, Regina H.; Galen, James E.

    2013-01-01

    Bacterial live vector vaccines represent a vaccine development strategy that offers exceptional flexibility. In this approach, genes encoding protective antigens of unrelated bacterial, viral or parasitic pathogens are expressed in an attenuated bacterial vaccine strain that delivers these foreign antigens to the immune system, thereby eliciting relevant immune responses. Rather than expressing these antigens using low copy expression plasmids, here we pursue expression of foreign proteins from the live vector chromosome. Our strategy is designed to compensate for the inherent disadvantage of loss of gene dosage (vs. plasmid-based expression) by integrating antigen-encoding gene cassettes into multiple chromosomal sites already inactivated in an attenuated Salmonella enterica serovar Typhi vaccine candidate. We tested expression of a cassette encoding the green fluorescent protein (GFPuv) integrated separately into native guaBA, htrA or clyA chromosomal loci. Using single integrations, we show that expression levels of GFPuv are significantly affected by the site of integration, regardless of the inclusion of additional strong promoters within the incoming cassette. Using cassettes integrated into both guaBA and htrA, we observe cumulative synthesis levels from two integration sites superior to single integrations. Most importantly, we observe that GFPuv expression increases in a growth phase-dependent manner, suggesting that foreign antigen synthesis may be “tuned” to the physiology of the live vaccine. We expect this novel platform expression technology to prove invaluable in the development of a wide variety of multivalent live vector vaccines, capable of expressing multiple antigens from both chromosomal and plasmid-based expression systems within a single strain. PMID:23406777

  14. Targeted Surface Expression of an Exogenous Antigen in Stably Transfected Babesia bovis

    PubMed Central

    Laughery, Jacob M.; Knowles, Donald P.; Schneider, David A.; Bastos, Reginaldo G.; McElwain, Terry F.; Suarez, Carlos E.

    2014-01-01

    Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine

  15. Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis.

    PubMed

    Laughery, Jacob M; Knowles, Donald P; Schneider, David A; Bastos, Reginaldo G; McElwain, Terry F; Suarez, Carlos E

    2014-01-01

    Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine

  16. Plasmodium falciparum Variant Surface Antigen Expression Patterns during Malaria

    PubMed Central

    2005-01-01

    The variant surface antigens expressed on Plasmodium falciparum–infected erythrocytes are potentially important targets of immunity to malaria and are encoded, at least in part, by a family of var genes, about 60 of which are present within every parasite genome. Here we use semi-conserved regions within short var gene sequence “tags” to make direct comparisons of var gene expression in 12 clinical parasite isolates from Kenyan children. A total of 1,746 var clones were sequenced from genomic and cDNA and assigned to one of six sequence groups using specific sequence features. The results show the following. (1) The relative numbers of genomic clones falling in each of the sequence groups was similar between parasite isolates and corresponded well with the numbers of genes found in the genome of a single, fully sequenced parasite isolate. In contrast, the relative numbers of cDNA clones falling in each group varied considerably between isolates. (2) Expression of sequences belonging to a relatively conserved group was negatively associated with the repertoire of variant surface antigen antibodies carried by the infected child at the time of disease, whereas expression of sequences belonging to another group was associated with the parasite “rosetting” phenotype, a well established virulence determinant. Our results suggest that information on the state of the host–parasite relationship in vivo can be provided by measurements of the differential expression of different var groups, and need only be defined by short stretches of sequence data. PMID:16304608

  17. Melanocyte antigen triggers autoimmunity in human psoriasis.

    PubMed

    Arakawa, Akiko; Siewert, Katherina; Stöhr, Julia; Besgen, Petra; Kim, Song-Min; Rühl, Geraldine; Nickel, Jens; Vollmer, Sigrid; Thomas, Peter; Krebs, Stefan; Pinkert, Stefan; Spannagl, Michael; Held, Kathrin; Kammerbauer, Claudia; Besch, Robert; Dornmair, Klaus; Prinz, Jörg C

    2015-12-14

    Psoriasis vulgaris is a common T cell-mediated inflammatory skin disease with a suspected autoimmune pathogenesis. The human leukocyte antigen (HLA) class I allele, HLA-C*06:02, is the main psoriasis risk gene. Epidermal CD8(+) T cells are essential for psoriasis development. Functional implications of HLA-C*06:02 and mechanisms of lesional T cell activation in psoriasis, however, remained elusive. Here we identify melanocytes as skin-specific target cells of an HLA-C*06:02-restricted psoriatic T cell response. We found that a Vα3S1/Vβ13S1 T cell receptor (TCR), which we had reconstituted from an epidermal CD8(+) T cell clone of an HLA-C*06:02-positive psoriasis patient specifically recognizes HLA-C*06:02-positive melanocytes. Through peptide library screening, we identified ADAMTS-like protein 5 (ADAMTSL5) as an HLA-C*06:02-presented melanocytic autoantigen of the Vα3S1/Vβ13S1 TCR. Consistent with the Vα3S1/Vβ13S1-TCR reactivity, we observed numerous CD8(+) T cells in psoriasis lesions attacking melanocytes, the only epidermal cells expressing ADAMTSL5. Furthermore, ADAMTSL5 stimulation induced the psoriasis signature cytokine, IL-17A, in CD8(+) T cells from psoriasis patients only, supporting a role as psoriatic autoantigen. This unbiased analysis of a TCR obtained directly from tissue-infiltrating CD8(+) T cells reveals that in psoriasis HLA-C*06:02 directs an autoimmune response against melanocytes through autoantigen presentation. We propose that HLA-C*06:02 may predispose to psoriasis via this newly identified autoimmune pathway. PMID:26621454

  18. Melanocyte antigen triggers autoimmunity in human psoriasis

    PubMed Central

    Arakawa, Akiko; Siewert, Katherina; Stöhr, Julia; Besgen, Petra; Kim, Song-Min; Rühl, Geraldine; Nickel, Jens; Vollmer, Sigrid; Thomas, Peter; Krebs, Stefan; Pinkert, Stefan; Spannagl, Michael; Held, Kathrin; Kammerbauer, Claudia; Besch, Robert; Dornmair, Klaus

    2015-01-01

    Psoriasis vulgaris is a common T cell–mediated inflammatory skin disease with a suspected autoimmune pathogenesis. The human leukocyte antigen (HLA) class I allele, HLA-C*06:02, is the main psoriasis risk gene. Epidermal CD8+ T cells are essential for psoriasis development. Functional implications of HLA-C*06:02 and mechanisms of lesional T cell activation in psoriasis, however, remained elusive. Here we identify melanocytes as skin-specific target cells of an HLA-C*06:02–restricted psoriatic T cell response. We found that a Vα3S1/Vβ13S1 T cell receptor (TCR), which we had reconstituted from an epidermal CD8+ T cell clone of an HLA-C*06:02–positive psoriasis patient specifically recognizes HLA-C*06:02–positive melanocytes. Through peptide library screening, we identified ADAMTS-like protein 5 (ADAMTSL5) as an HLA-C*06:02–presented melanocytic autoantigen of the Vα3S1/Vβ13S1 TCR. Consistent with the Vα3S1/Vβ13S1-TCR reactivity, we observed numerous CD8+ T cells in psoriasis lesions attacking melanocytes, the only epidermal cells expressing ADAMTSL5. Furthermore, ADAMTSL5 stimulation induced the psoriasis signature cytokine, IL-17A, in CD8+ T cells from psoriasis patients only, supporting a role as psoriatic autoantigen. This unbiased analysis of a TCR obtained directly from tissue-infiltrating CD8+ T cells reveals that in psoriasis HLA-C*06:02 directs an autoimmune response against melanocytes through autoantigen presentation. We propose that HLA-C*06:02 may predispose to psoriasis via this newly identified autoimmune pathway. PMID:26621454

  19. Human immune response to Mycobacterium tuberculosis antigens.

    PubMed Central

    Havlir, D V; Wallis, R S; Boom, W H; Daniel, T M; Chervenak, K; Ellner, J J

    1991-01-01

    Little is known about the immunodominant or protective antigens of Mycobacterium tuberculosis in humans. Cell-mediated immunity is necessary for protection, and healthy tuberculin-positive individuals are relatively resistant to exogenous reinfection. We compared the targets of the cell-mediated immune response in healthy tuberculin-positive individuals to those of tuberculosis patients and tuberculin-negative persons. By using T-cell Western blotting (immunoblotting) of nitrocellulose-bound M. tuberculosis culture filtrate, peaks of T-cell blastogenic activity were identified in the healthy tuberculin reactors at 30, 37, 44, 57, 64, 71 and 88 kDa. Three of these fractions (30, 64, and 71 kDa) coincided with previously characterized proteins: antigen 6/alpha antigen, HSP60, and HSP70, respectively. The blastogenic responses to purified M. tuberculosis antigen 6/alpha antigen and BCG HSP60 were assessed. When cultured with purified antigen 6/alpha antigen, lymphocytes of healthy tuberculin reactors demonstrated greater [3H]thymidine incorporation than either healthy tuberculin-negative controls or tuberculous patients (8,113 +/- 1,939 delta cpm versus 645 +/- 425 delta cpm and 1,019 +/- 710 delta cpm, respectively; P less than 0.01). Healthy reactors also responded to HSP60, although to a lesser degree than antigen 6/alpha antigen (4,276 +/- 1,095 delta cpm; P less than 0.05). Partially purified HSP70 bound to nitrocellulose paper elicited a significant lymphocyte blastogenic response in two of six of the tuberculous patients but in none of the eight healthy tuberculin reactors. Lymphocytes of none of five tuberculin-negative controls responded to recombinant antigens at 14 or 19 kDa or to HSP70. Antibody reactivity generally was inversely correlated with blastogenic response: tuberculous sera had high titer antibody to M. tuberculosis culture filtrate in a range from 35 to 180 kDa. This is the first systematic evaluation of the human response to a panel of native

  20. Genomic Characterization of Variable Surface Antigens Reveals a Telomere Position Effect as a Prerequisite for RNA Interference-Mediated Silencing in Paramecium tetraurelia

    PubMed Central

    Baranasic, Damir; Oppermann, Timo; Cheaib, Miriam; Cullum, John; Schmidt, Helmut

    2014-01-01

    ABSTRACT Antigenic or phenotypic variation is a widespread phenomenon of expression of variable surface protein coats on eukaryotic microbes. To clarify the mechanism behind mutually exclusive gene expression, we characterized the genetic properties of the surface antigen multigene family in the ciliate Paramecium tetraurelia and the epigenetic factors controlling expression and silencing. Genome analysis indicated that the multigene family consists of intrachromosomal and subtelomeric genes; both classes apparently derive from different gene duplication events: whole-genome and intrachromosomal duplication. Expression analysis provides evidence for telomere position effects, because only subtelomeric genes follow mutually exclusive transcription. Microarray analysis of cultures deficient in Rdr3, an RNA-dependent RNA polymerase, in comparison to serotype-pure wild-type cultures, shows cotranscription of a subset of subtelomeric genes, indicating that the telomere position effect is due to a selective occurrence of Rdr3-mediated silencing in subtelomeric regions. We present a model of surface antigen evolution by intrachromosomal gene duplication involving the maintenance of positive selection of structurally relevant regions. Further analysis of chromosome heterogeneity shows that alternative telomere addition regions clearly affect transcription of closely related genes. Consequently, chromosome fragmentation appears to be of crucial importance for surface antigen expression and evolution. Our data suggest that RNAi-mediated control of this genetic network by trans-acting RNAs allows rapid epigenetic adaptation by phenotypic variation in combination with long-term genetic adaptation by Darwinian evolution of antigen genes. PMID:25389173

  1. Overexpressed oncogenic tumor-self antigens

    PubMed Central

    Bright, Robert K; Bright, Jennifer D; Byrne, Jennifer A

    2014-01-01

    Overexpressed tumor-self antigens represent the largest group of candidate vaccine targets. Those exhibiting a role in oncogenesis may be some of the least studied but perhaps most promising. This review considers this subset of self antigens by highlighting vaccine efforts for some of the better known members and focusing on TPD52, a new promising vaccine target. We shed light on the importance of both preclinical and clinical vaccine studies demonstrating that tolerance and autoimmunity (presumed to preclude this class of antigens from vaccine development) can be overcome and do not present the obstacle that might have been expected. The potential of this class of antigens for broad application is considered, possibly in the context of low tumor burden or adjuvant therapy, as is the need to understand mechanisms of tolerance that are relatively understudied. PMID:25483660

  2. Immunotherapy in Acute Leukemias: Implications and Perspectives Using Wt1 Antigen.

    PubMed

    Cebinelli, Guilherme Cesar Martelossi; DE Sousa Pereira, Nathália; Sena, Michelle Mota; DE Oliveira, Carlos Eduardo Coral; Fujita, Thiago Cezar; DA Rocha, Sérgio Paulo Dejato; DE Abreu Oliveira, Francisco José; Marinello, Poliana Camila; Watanabe, Maria Angelica Ehara

    2016-08-01

    The WT1 gene encodes a transcription factor involved in regulation of many cellular processes, including proliferation, differentiation, mRNA processing and apoptosis, besides acting as a transcription repressor of growth factors and their receptors' genes. This gene is expressed at high levels in several types of cancers, including acute leukemias. In this regard, many studies have identified WT1 protein as a tumor antigen, considered a target molecule for clinical application in human acute leukemias. Immunotherapy using WT1 antigen has been effective in stimulating immune responses against leukemic cells. Regarding adoptive immunotherapy, the use of dendritic cells (DCs) for the WT1-specific cytotoxic T cells generation proved to be efficient in the development and maintenance of immunologic cells. Therefore, these therapeutic methods, that provided enthusiasm for moving ahead, highlight several opportunities and challenges to be used in clinical practice for managing acute leukemias. PMID:27466479

  3. Genetic and antigenic characterization of H1 influenza viruses from United States swine from 2008

    PubMed Central

    Lorusso, Alessio; Vincent, Amy L.; Harland, Michelle L.; Alt, David; Bayles, Darrell O.; Swenson, Sabrina L.; Gramer, Marie R.; Russell, Colin A.; Smith, Derek J.; Lager, Kelly M.; Lewis, Nicola S.

    2011-01-01

    Prior to the introduction of the 2009 pandemic H1N1 virus from humans into pigs, four phylogenetic clusters (α-, β-, γ- and δ) of the haemagglutinin (HA) gene from H1 influenza viruses could be found in US swine. Information regarding the antigenic relatedness of the H1 viruses was lacking due to the dynamic and variable nature of swine lineage H1. We characterized 12 H1 isolates from 2008 by using 454 genome-sequencing technology and phylogenetic analysis of all eight gene segments and by serological cross-reactivity in the haemagglutination inhibition (HI) assay. Genetic diversity was demonstrated in all gene segments, but most notably in the HA gene. The gene segments from the 2009 pandemic H1N1 formed clusters separate from North American swine lineage viruses, suggesting progenitors of the pandemic virus were not present in US pigs immediately prior to 2009. Serological cross-reactivity paired with antigenic cartography demonstrated that the viruses in the different phylogenetic clusters are also antigenically divergent. PMID:21177926

  4. Mapping Epitopes on a Protein Antigen by the Proteolysis of Antigen-Antibody Complexes

    NASA Astrophysics Data System (ADS)

    Jemmerson, Ronald; Paterson, Yvonne

    1986-05-01

    A monoclonal antibody bound to a protein antigen decreases the rate of proteolytic cleavage of the antigen, having the greatest effect on those regions involved in antibody contact. Thus, an epitope can be identified by the ability of the antibody to protect one region of the antigen more than others from proteolysis. By means of this approach, two distinct epitopes, both conformationally well-ordered, were characterized on horse cytochrome c.

  5. Tales of Antigen Evasion from CAR Therapy.

    PubMed

    Sadelain, Michel

    2016-06-01

    Both T cells bearing chimeric antigen receptors and tumor-specific antibodies can successfully target some malignancies, but antigen escape can lead to relapse. Two articles in this issue of Cancer Immunology Research explore what effective countermeasures may prevent it. Cancer Immunol Res; 4(6); 473-473. ©2016 AACRSee articles by Zah et al., p. 498, and Rufener et al., p. 509. PMID:27252092

  6. Vertebrate Cells Express Protozoan Antigen after Hybridization

    NASA Astrophysics Data System (ADS)

    Crane, Mark St. J.; Dvorak, James A.

    1980-04-01

    Epimastigotes, the invertebrate host stage of Trypanosoma cruzi, the protozoan parasite causing Chagas' disease in man, were fused with vertebrate cells by using polyethylene glycol. Hybrid cells were selected on the basis of T. cruzi DNA complementation of biochemical deficiencies in the vertebrate cells. Some clones of the hybrid cells expressed T. cruzi-specific antigen. It might be possible to use selected antigens obtained from the hybrids as vaccines for immunodiagnosis or for elucidation of the pathogenesis of Chagas' disease.

  7. Genes and Gene Therapy

    MedlinePlus

    ... a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  8. Genes and Gene Therapy

    MedlinePlus

    ... correctly, a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  9. Safety of targeting tumor endothelial cell antigens.

    PubMed

    Wagner, Samuel C; Riordan, Neil H; Ichim, Thomas E; Szymanski, Julia; Ma, Hong; Perez, Jesus A; Lopez, Javier; Plata-Munoz, Juan J; Silva, Francisco; Patel, Amit N; Kesari, Santosh

    2016-01-01

    The mechanisms underlying discrimination between "self" and "non-self", a central immunological principle, require careful consideration in immune oncology therapeutics where eliciting anti-cancer immunity must be weighed against the risk of autoimmunity due to the self origin of tumors. Whole cell vaccines are one promising immunotherapeutic avenue whereby a myriad of tumor antigens are introduced in an immunogenic context with the aim of eliciting tumor rejection. Despite the possibility collateral damage to healthy tissues, cancer immunotherapy can be designed such that off target autoimmunity remains limited in scope and severity or completely non-existent. Here we provide an immunological basis for reconciling the safety of cancer vaccines, focusing on tumor endothelial cell vaccines, by discussing the following topics: (a) Antigenic differences between neoplastic and healthy tissues that can be leveraged in cancer vaccine design; (b) The layers of tolerance that control T cell responses directed against antigens expressed in healthy tissues and tumors; and, (c) The hierarchy of antigenic epitope selection and display in response to whole cell vaccines, and how antigen processing and presentation can afford a degree of selectivity against tumors. We conclude with an example of early clinical data utilizing ValloVax™, an immunogenic placental endothelial cell vaccine that is being advanced to target the tumor endothelium of diverse cancers, and we report on the safety and efficacy of ValloVax™ for inducing immunity against tumor endothelial antigens. PMID:27071457

  10. Variations in O-antigen biosynthesis and O-acetylation associated with altered phage sensitivity in Escherichia coli 4s.

    PubMed

    Knirel, Yuriy A; Prokhorov, Nikolai S; Shashkov, Alexander S; Ovchinnikova, Olga G; Zdorovenko, Evelina L; Liu, Bin; Kostryukova, Elena S; Larin, Andrey K; Golomidova, Alla K; Letarov, Andrey V

    2015-03-01

    The O polysaccharide of the lipopolysaccharide (O antigen) of Gram-negative bacteria often serves as a receptor for bacteriophages that can make the phage dependent on a given O-antigen type, thus supporting the concept of the adaptive significance of the O-antigen variability in bacteria. The O-antigen layer also modulates interactions of many bacteriophages with their hosts, limiting the access of the viruses to other cell surface receptors. Here we report variations of O-antigen synthesis and structure in an environmental Escherichia coli isolate, 4s, obtained from horse feces, and its mutants selected for resistance to bacteriophage G7C, isolated from the same fecal sample. The 4s O antigen was found to be serologically, structurally, and genetically related to the O antigen of E. coli O22, differing only in side-chain α-D-glucosylation in the former, mediated by a gtr locus on the chromosome. Spontaneous mutations of E. coli 4s occurring with an unusually high frequency affected either O-antigen synthesis or O-acetylation due to the inactivation of the gene encoding the putative glycosyltransferase WclH or the putative acetyltransferase WclK, respectively, by the insertion of IS1-like elements. These mutations induced resistance to bacteriophage G7C and also modified interactions of E. coli 4s with several other bacteriophages conferring either resistance or sensitivity to the host. These findings suggest that O-antigen synthesis and O-acetylation can both ensure the specific recognition of the O-antigen receptor following infection by some phages and provide protection of the host cells against attack by other phages. PMID:25512310

  11. Activation of clones producing self-reactive antibodies by foreign antigen and antiidiotype antibody carrying the internal image of the antigen.

    PubMed Central

    Bailey, N C; Fidanza, V; Mayer, R; Mazza, G; Fougereau, M; Bona, C

    1989-01-01

    Because we found in previous work that a high fraction of antibodies exhibiting various specificities bound to glutamic acid 50-tyrosine50 homopolymer (GT) and expressed pGAT cross-reactive idiotype (IdX), we studied the activation of clones producing multireactive antibodies in 1-mo-old MRL/lpr and C3H/HeJ mice bearing VHJ haplotype. The activation of such clones was studied after mice were immunized with GT in CFA, HP20 (an anti-Id MAb carrying the internal image of GT in the D region), and a synthetic peptide corresponding to the D segment of HP20. Our results indicate that immunized mice produced both GT- and self-reactive antibodies. Study of the immunochemical properties of MAb showed that they exhibit multispecific properties and bind with similar-affinity constants to GT or self-antigens such as DNA, Smith antigen (Sm), and IgG2a. An important fraction of antibodies obtained from MRL/lpr mice immunized with HP20 expressed pGAT IdX and some of these antibodies share IdX expressed on anti-DNA, Sm, and rheumatoid factor (RFs) antibodies. The hybridomas producing multispecific autoantibodies use heavy-chain- (VH) and light-chain-variable region (VK) genes from various V gene families, suggesting that they do not derive from the pool of GAT precursors. Sequencing of VH and VK genes of two antibodies show that they can use closely related VHJ558, unmutated VK1, or different VK genes than those used by anti-GT antibodies. Our data demonstrate that clones producing antibodies binding to GT and self-antigens with similar-affinity constants can be activated by foreign or anti-Id antibodies carrying the internal image of the antigen or even by a synthetic peptide corresponding to the D segment of anti-Id antibodies. Images PMID:2760212

  12. Genotyping of human leukocyte antigen (HLA) ancestral haplotypes as prognostic marker in cancer using PCR analysis.

    PubMed

    Villabona, Lisa; Andersson, Emilia; Marchesi, Maddalena; Masucci, Giuseppe V

    2014-01-01

    The major histocompatibility complex (MHC) comprises a set of genes that are essential to immunity and surveillance against neoplastic transformation. MHC antigens not only regulate antitumor immune responses in experimental animal models but also directly correlate with survival and prognosis of patients with various types of cancers. Effective recognition of tumor cells by effector T cells may be affected by the genotype and the extent of expression of human leukocyte antigen (HLA)-peptide complexes. Therefore, MHC antigens may serve as potential biomarkers for prognosis and allow selection of cancer patients for specific therapy. We describe PCR-based method to determine the HLA genotype in healthy individuals and patients using blood and tumor tissue as DNA source. PMID:24258987

  13. Sperm protein 17 is an oncofetal antigen: a lesson from a murine model.

    PubMed

    Arnaboldi, F; Menon, A; Menegola, E; Di Renzo, F; Mirandola, L; Grizzi, F; Figueroa, J A; Cobos, E; Jenkins, M; Barajon, I; Chiriva-Internati, Maurizio

    2014-10-01

    Sperm protein 17 (Sp17) was originally identified in the flagellum of spermatozoa and subsequently included in the subfamily of tumor-associated antigens known as cancer-testes antigens (CTA). Sp17 has been associated with the motility and migratory capacity in tumor cells, representing a link between gene expression patterns in germinal and tumor cells of different histological origins. Here we review the relevance of Sp17 expression in the mouse embryo and cancerous tissues, and present additional data demonstrating Sp17 complex expression pattern in this murine model. The expression of Sp17 in embryonic as well as adult neoplastic cells, but not normal tissues, suggests this protein should be considered an "oncofetal antigen." Further investigations are necessary to elucidate the mechanisms and functional significance of Sp17 aberrant expression in human adult cells and its implication in the pathobiology of cancer. PMID:24811209

  14. Novel Antitumor Strategy Utilizing a Plasmid Expressing a Mycobacterium tuberculosis Antigen as a “Danger Signal” to Block Immune Escape of Tumor Cells

    PubMed Central

    Koyama, Yoshiyuki; Yoshihara, Chieko; Ito, Tomoko

    2015-01-01

    Immune escape of tumor cells is one of the main obstacles hindering the effectiveness of cancer immunotherapy. We developed a novel strategy to block immune escape by transfecting tumor cells in vivo with genes of pathogenic antigens from Mycobacterium tuberculosis (TB). This induces presentation of the TB antigen on tumor cell surfaces, which can be recognized by antigen presenting cells (APCs) as a “danger signal” to stimulate antitumor immune response. This strategy is also expected to amplify the immune response against tumor-associated antigens, and block immune escape of the tumor. DNA/PEI/chondroitin sulfate ternary complex is a highly effective non-viral gene vector system for in vivo transfection. A therapeutic complex was prepared using a plasmid encoding the TB antigen, early secretory antigenic target-6 (ESAT-6). This was injected intratumorally into syngeneic tumor-bearing mice, and induced significant tumor growth suppression comparable to or higher than similar complexes expressing cytokines such as interleukin-2 (IL-2) and interleukin-12 (IL-12). Co-transfection of the cytokine-genes and the ESAT-6-gene enhanced the antitumor efficacy of either treatment alone. In addition, complete tumor regression was achieved with the combination of ESAT-6 and IL-2 genes. PMID:26213962

  15. Novel Antitumor Strategy Utilizing a Plasmid Expressing a Mycobacterium tuberculosis Antigen as a "Danger Signal" to Block Immune Escape of Tumor Cells.

    PubMed

    Koyama, Yoshiyuki; Yoshihara, Chieko; Ito, Tomoko

    2015-01-01

    Immune escape of tumor cells is one of the main obstacles hindering the effectiveness of cancer immunotherapy. We developed a novel strategy to block immune escape by transfecting tumor cells in vivo with genes of pathogenic antigens from Mycobacterium tuberculosis (TB). This induces presentation of the TB antigen on tumor cell surfaces, which can be recognized by antigen presenting cells (APCs) as a "danger signal" to stimulate antitumor immune response. This strategy is also expected to amplify the immune response against tumor-associated antigens, and block immune escape of the tumor. DNA/PEI/chondroitin sulfate ternary complex is a highly effective non-viral gene vector system for in vivo transfection. A therapeutic complex was prepared using a plasmid encoding the TB antigen, early secretory antigenic target-6 (ESAT-6). This was injected intratumorally into syngeneic tumor-bearing mice, and induced significant tumor growth suppression comparable to or higher than similar complexes expressing cytokines such as interleukin-2 (IL-2) and interleukin-12 (IL-12). Co-transfection of the cytokine-genes and the ESAT-6-gene enhanced the antitumor efficacy of either treatment alone. In addition, complete tumor regression was achieved with the combination of ESAT-6 and IL-2 genes. PMID:26213962

  16. Amino acid sequence of the serine-repeat antigen (SERA) of Plasmodium falciparum determined from cloned cDNA.

    PubMed

    Bzik, D J; Li, W B; Horii, T; Inselburg, J

    1988-09-01

    We report the isolation of cDNA clones for a Plasmodium falciparum gene that encodes the complete amino acid sequence of a previously identified exported blood stage antigen. The Mr of this antigen protein had been determined by sodium dodecylsulphate-polyacrylamide gel electrophoresis analysis, by different workers, to be 113,000, 126,000, and 140,000. We show, by cDNA nucleotide sequence analysis, that this antigen gene encodes a 989 amino acid protein (111 kDa) that contains a potential signal peptide, but not a membrane anchor domain. In the FCR3 strain the serine content of the protein was 11%, of which 57% of the serine residues were localized within a 201 amino acid sequence that included 35 consecutive serine residues. The protein also contained three possible N-linked glycosylation sites and numerous possible O-linked glycosylation sites. The mRNA was abundant during late trophozoite-schizont parasite stages. We propose to identity this antigen, which had been called p126, by the acronym SERA, serine-repeat antigen, based on its complete structure. The usefulness of the cloned cDNA as a source of a possible malaria vaccine is considered in view of the previously demonstrated ability of the antigen to induce parasite-inhibitory antibodies and a protective immune response in Saimiri monkeys. PMID:2847041

  17. Do lymphocytes from Chagasic patients respond to heart antigens?

    PubMed Central

    Todd, C W; Todd, N R; Guimaraes, A C

    1983-01-01

    Lymphocyte transformation studies of nonadherent lymphocytes from chronic Chagasic and uninfected persons demonstrated that responses of all individuals to a mouse heart homogenate showed a correlation with responses to streptococcal antigens. Considering the known cross-reactions between streptococcal and cardiac antigens and the high reactivity of Chagasic patients to streptococcal antigens, it is possible that positive lymphocyte transformation to unfractionated heart antigen preparations may not represent specific reactivity to heart antigens. PMID:6404836

  18. Antigenic profiling of Yersinia pestis infection in the Wyoming coyote (Canis latrans)

    USGS Publications Warehouse

    Vernati, G.; Edwards, W.H.; Rocke, T.E.; Little, S.F.; Andrews, G.P.

    2011-01-01

    Although Yersinia pestis is classified as a "high-virulence" pathogen, some host species are variably susceptible to disease. Coyotes (Canis latrans) exhibit mild, if any, symptoms during infection, but antibody production occurs postinfection. This immune response has been reported to be against the F1 capsule, although little subsequent characterization has been conducted. To further define the nature of coyote humoral immunity to plague, qualitative serology was conducted to assess the antiplague antibody repertoire. Humoral responses to six plasmid-encoded Y. pestis virulence factors were first examined. Of 20 individual immune coyotes, 90% were reactive to at least one other antigen in the panel other than F1. The frequency of reactivity to low calcium response plasmid (pLcr)-encoded Yersinia protein kinase A (YpkA) and Yersinia outer protein D (YopD) was significantly greater than that previously observed in a murine model for plague. Additionally, both V antigen and plasminogen activator were reactive with over half of the serum samples tested. Reactivity to F1 was markedly less frequent in coyotes (35%). Twenty previously tested antibody-negative samples were also examined. While the majority were negative across the panel, 15% were positive for 1-3 non-F1 antigens. In vivo-induced antigen technology employed to identify novel chromosomal genes of Y. pestis that are up-regulated during infection resulted in the identification of five proteins, including a flagellar component (FliP) that was uniquely reactive with the coyote serum compared with immune serum from two other host species. Collectively, these data suggest that humoral immunity to pLcr-encoded antigens and the pesticin plasmid (pPst)-encoded Pla antigen may be relevant to plague resistance in coyotes. The serologic profile of Y. pestis chromosomal antigens up-regulated in vivo specific to C. latrans may provide insight into the differences in the pathogen-host responses during Y. pestis infection.

  19. Novel aspects of the Z and R3 antigens of Streptococcus agalactiae revealed by immunological testing.

    PubMed

    Maeland, Johan A; Radtke, Andreas; Lyng, Randi V; Mavenyengwa, Rooyen T

    2013-04-01

    Group B streptococci (GBS) are important human and bovine pathogens which can be classified by a variety of phenotype- and gene-based techniques. The capsular polysaccharide and strain-variable, surface-anchored proteins are particularly important phenotypic markers. In an earlier study, a previously unrecognized protein antigen called Z was described. It was expressed by 27.2% of GBS strains from Zimbabwe, usually in combination with R3 protein expression. In this study, a putative Z-specific antiserum actually contained antibodies against two different antigens named Z1 and Z2; Z1 was >250 kDa in molecular mass. Z1, Z2, and R3 generated multiple stained bands on Western blots and showed similar chromatographic characteristics with respect to molecular mass, aggregate formation, and charge. Of 28 reference and prototype GBS strains examined, 8/28 (28.5%) isolates expressed one, two, or all three of the Z1, Z2, and R3 antigens; 4/28 expressed all three antigens; 2/28 expressed Z2 and R3; 1/28 expressed Z1 only; and 1/28 expressed R3 only. Twenty (71.5%) of the 28 isolates expressed none of the three antigens. Expression of one or more of these antigens was shown by isolates of the capsular polysaccharide types Ia, Ib, V, and IX and NT strains and occurred in combination with expression of various other strain-variable and surface-localized protein antigens. When used as serosubtype markers, Z1, Z2, and R3 affected existing GBS serotype designations for some of the isolates. For instance, the R3 reference strain Prague 10/84 (ATCC 49447) changed serotype markers from V/R3 to V/R3, Z1, and Z2. Other isolates may change correspondingly, implying consequences for GBS serotyping and research. PMID:23408530

  20. 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

  1. Nephritogenic antigen determinants in epidermal and renal basement membranes of kindreds with Alport-type familial nephritis.

    PubMed Central

    Kashtan, C; Fish, A J; Kleppel, M; Yoshioka, K; Michael, A F

    1986-01-01

    We probed epidermal basement membranes (EBM) of acid-urea denatured skin from members of kindreds with Alport-type familial nephritis (FN) for the presence of antigens reactive with Goodpasture sera (GPS) and serum (FNS) from an Alport patient who developed anti-glomerular basement membrane (GBM) nephritis in a renal allograft. By immunoblotting, GPS reacted primarily with the 28,000 molecular weight (mol wt) monomer but also the 24,000 mol wt and 26,000 mol wt monomers of the noncollagenous globular domain (NC1) of type IV collagen from normal human GBM, while FNS identified only the 26,000-mol wt monomer. FNS reacted with EBM of 12 controls and nine unaffected male kindred members but not EBM of eight affected males. Five affected females exhibited interrupted reactivity of FNS with EBM. GPS showed variable reactivity with EBM and was not discriminating with respect to Alport-type FN. FNS did not stain renal basement members of five affected males. However, the EBM, tubular basement membrane, and Bowman's capsules of affected males contained antigens reactive with GPS. These immunochemical studies suggest that the FNS antigen is distinct from Goodpasture antigen(s). The expression of FNS antigen located on the NC1 domain of type IV collagen is altered in basement membranes of patients with Alport-type FN, and the distribution of this antigenic anomaly within kindreds suggests X-linked dominant transmission of a defective gene. Images PMID:2428839

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