Sample records for class i-restricted antigen

  1. Inhibition of MHC class I-restricted antigen presentation by γ2-herpesviruses

    Stevenson, Philip G.; Efstathiou, Stacey; Doherty, Peter C.; Lehner, Paul J.


    The γ-herpesviruses, in contrast to the α- and β-herpesviruses, are not known to inhibit antigen presentation to CD8+ cytotoxic T lymphocytes (CTLs) during lytic cycle replication. However, murine γ-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, γ-herpesvirus 68 down-regulates surface MHC class I expression o...

  2. Linkage of bacterial protein synthesis and presentation of MHC class I-restricted Listeria monocytogenes-derived antigenic peptides.

    Silke Grauling-Halama

    Full Text Available The processing and MHC class I-restricted presentation of antigenic peptides derived from the p60 protein of the facultative intracellular bacterium Listeria monocytogenes is tightly linked to bacterial protein synthesis. We used non-linear regression analysis to fit a mathematical model of bacterial antigen processing to a published experimental data set showing the accumulation and decay of p60-derived antigenic peptides in L. monocytogenes-infected cells. Two alternative models equally describe the experimental data. The simulation accounting for a stable and a hypothetical rapidly degraded form of antigen predicts that the antigenic peptides p60 217-225 and p60 449-457 are derived from a putative instable form of p60 with an average intracellular half-life of approximately 3 minutes accounting for approximately 31% of all p60 molecules synthesized. The alternative model predicts that both antigenic peptides are processed from p60 degraded intracellularly with a half-life of 109 min and that antigen processing only occurs as long as bacterial protein synthesis is not inhibited. In order to decide between both models the intracellular accumulation of p60 in infected cells was studied experimentally and compared with model predictions. Inhibition of p60 degradation by the proteasome inhibitor epoxomicin revealed that during the first 3 h post infection approximately 30% of synthesized p60 molecules were degraded. This value is significantly lower than the approximately 50% degradation of p60 that would be expected in the presence of the predicted putative short-lived state of p60 and also fits precisely with the predictions of the alternative model, indicating that the tight connection of bacterial protein biosynthesis and antigen processing and presentation of L. monocyctogenes-derived antigenic peptides is not caused by the presence of a highly instable antigenic substrate.

  3. Human Leukocyte Antigen (HLA) Class I Restricted Epitope Discovery in Yellow Fewer and Dengue Viruses: Importance of HLA Binding Strength

    Lund, Ole; Nascimento, Eduardo J. M.; Maciel, Milton, Jr;


    Epitopes from all available full-length sequences of yellow fever virus (YFV) and dengue fever virus (DENV) restricted by Human Leukocyte Antigen class I (HLA-I) alleles covering 12 HLA-I supertypes were predicted using the NetCTL algorithm. A subset of 179 predicted YFV and 158 predicted DENV...... epitopes were selected using the EpiSelect algorithm to allow for optimal coverage of viral strains. The selected predicted epitopes were synthesized and approximately 75% were found to bind the predicted restricting HLA molecule with an affinity, K(D), stronger than 500 nM. The immunogenicity of 25 HLA......-A*02:01, 28 HLA-A*24:02 and 28 HLA-B*07:02 binding peptides was tested in three HLA-transgenic mice models and led to the identification of 17 HLA-A*02:01, 4 HLA-A*2402 and 4 HLA-B*07:02 immunogenic peptides. The immunogenic peptides bound HLA significantly stronger than the non-immunogenic peptides...

  4. Human cytomegalovirus pp65- and immediate early 1 antigen-specific HLA class I-restricted cytotoxic T cell responses induced by cross-presentation of viral antigens.

    Tabi, Z; Moutaftsi, M; Borysiewicz, L K


    Dendritic cells (DCs) play a pivotal role in the development of anti-viral CD8(+) CTL responses. This is straightforward if they are directly infected with virus, but is less clear in response to viruses that cannot productively infect DCS: Human CMV (HCMV) shows strain-specific cell tropism: fibroblast (Fb)-adapted laboratory strains (AD169) and recent clinical isolates do not infect DCs, whereas endothelial cell-adapted strains (TB40/E) result in productive lytic DC infection. However, we show here that uninfected DCs induce CD8(+) T cell cytotoxicity and IFN-gamma production against HCMV pp65 and immediate early 1 Ags following in vitro coculture with HCMV-AD169-infected Fbs, regardless of the HLA type of these FBS: CD8(+) T cell stimulation was inhibited by pretreatment of DCs with cytochalasin B or brefeldin A, indicating a phagosome/endosome to cytosol pathway. HCMV-infected Fbs were not apoptotic as measured by annexin V binding, and induction of apoptosis of infected Fbs in vitro did not augment CTL induction by DCs, suggesting a mechanism other than apoptosis in the initiation of cross-presentation. Furthermore, HCMV-infected Fbs provided a maturation signal for immature DCs during coculture, as evidenced by increased CD83 and HLA class II expression. Cross-presentation of HCMV Ags by host DCs enables these professional APCs to bypass some of the evasion mechanisms HCMV has developed to avoid T cell recognition. It may also serve to explain the presence of immediate early 1 Ag-specific CTLs in the face of pp65-induced inhibition of Ag presentation at the level of the infected cell. PMID:11313411

  5. IRF1 and NF-kB Restore MHC Class I-Restricted Tumor Antigen Processing and Presentation to Cytotoxic T Cells in Aggressive Neuroblastoma

    Cifaldi, Loredana; Antonucci, Chiara; Citti, Arianna; Boldrini, Renata; Pezzullo, Marco; Castellano, Aurora; Russo, Vincenzo; van der Bruggen, Pierre; Giacomini, Patrizio; Locatelli, Franco; Fruci, Doriana


    Neuroblastoma (NB), the most common solid extracranial cancer of childhood, displays a remarkable low expression of Major Histocompatibility Complex class I (MHC-I) and Antigen Processing Machinery (APM) molecules, including Endoplasmic Reticulum (ER) Aminopeptidases, and poorly presents tumor antigens to Cytotoxic T Lymphocytes (CTL). We have previously shown that this is due to low expression of the transcription factor NF-kB p65. Herein, we show that not only NF-kB p65, but also the Interferon Regulatory Factor 1 (IRF1) and certain APM components are low in a subset of NB cell lines with aggressive features. Whereas single transfection with either IRF1, or NF-kB p65 is ineffective, co-transfection results in strong synergy and substantial reversion of the MHC-I/APM-low phenotype in all NB cell lines tested. Accordingly, linked immunohistochemistry expression patterns between nuclear IRF1 and p65 on the one hand, and MHC-I on the other hand, were observed in vivo. Absence and presence of the three molecules neatly segregated between high-grade and low-grade NB, respectively. Finally, APM reconstitution by double IRF1/p65 transfection rendered a NB cell line susceptible to killing by anti MAGE-A3 CTLs, lytic efficiency comparable to those seen upon IFN-γ treatment. This is the first demonstration that a complex immune escape phenotype can be rescued by reconstitution of a limited number of master regulatory genes. These findings provide molecular insight into defective MHC-I expression in NB cells and provide the rational for T cell-based immunotherapy in NB variants refractory to conventional therapy. PMID:23071666

  6. Preformed purified peptide/major histocompatibility class I complexes are potent stimulators of class I-restricted T cell hybridomas

    Stryhn, A; Pedersen, L O; Ortiz-Navarrete, V;


    A panel of antigen-specific, major histocompatibility complex class I-restricted T cell hybridomas has been generated to examine the capacity of peptide/class I complexes to stimulate T cells at the molecular level. Peptide/class I complexes were generated in detergent solution, purified and...... quantitated. Latex particles were subsequently coated with known amounts of preformed complexes and used to stimulate the T cell hybridomas. Stimulation was specific, i.e. only the appropriate peptide/class I combination were stimulatory, and quite sensitive, i.e. as little as 300 complexes per bead could be...... detected by the T cells. Preformed complexes were about 500,000 times more potent than free peptide in terms of T cell stimulation, demonstrating the physiological relevancy of the biochemically generated complexes. Surprisingly, the majority (including the most sensitive of the hybridomas) had lost CD8...

  7. A hybrid approach for predicting promiscuous MHC class I restricted T cell epitopes

    Manoj Bhasin; G P S Raghava


    In the present study, a systematic attempt has been made to develop an accurate method for predicting MHC class I restricted T cell epitopes for a large number of MHC class I alleles. Initially, a quantitative matrix (QM)-based method was developed for 47 MHC class I alleles having at least 15 binders. A secondary artificial neural network (ANN)-based method was developed for 30 out of 47 MHC alleles having a minimum of 40 binders. Combination of these ANN- and QM-based prediction methods for 30 alleles improved the accuracy of prediction by 6% compared to each individual method. Average accuracy of hybrid method for 30 MHC alleles is 92.8%. This method also allows prediction of binders for 20 additional alleles using QM that has been reported in the literature, thus allowing prediction for 67 MHC class I alleles. The performance of the method was evaluated using jack-knife validation test. The performance of the methods was also evaluated on blind or independent data. Comparison of our method with existing MHC binder prediction methods for alleles studied by both methods shows that our method is superior to other existing methods. This method also identifies proteasomal cleavage sites in antigen sequences by implementing the matrices described earlier. Thus, the method that we discover allows the identification of MHC class I binders (peptides binding with many MHC alleles) having proteasomal cleavage site at C-terminus. The user-friendly result display format (HTML-II) can assist in locating the promiscuous MHC binding regions from antigen sequence. The method is available on the web at and its mirror site is available at

  8. Impact of HLA class I restricted T cells on HIV-1 disease progression

    Schellens, I.M.M.


    This thesis focuses on the impact of HLA class I restricted T cells on HIV-1 disease progression. It is generally accepted that cytotoxic T lymphocytes (CTL) play an important role in controlling HIV replication. In line with this, it has been well established that HLA class I alleles influence the

  9. Recognition of a subregion of human proinsulin by class I-restricted T cells in type 1 diabetic patients.

    Toma, Andréa; Haddouk, Samy; Briand, Jean-Paul; Camoin, Luc; Gahery, Hanne; Connan, Francine; Dubois-Laforgue, Danielle; Caillat-Zucman, Sophie; Guillet, Jean-Gérard; Carel, Jean-Claude; Muller, Sylviane; Choppin, Jeannine; Boitard, Christian


    Proinsulin is a key autoantigen in type 1 diabetes. Evidence in the mouse has underscored the importance of the insulin B chain region in autoimmunity to pancreatic beta cells. In man, a majority of proteasome cleavage sites are predicted by proteasome cleavage algorithms within this region. To study CD8+ T cell responses to the insulin B chain and adjacent C peptide, we selected 8- to 11-mer peptides according to proteasome cleavage patterns obtained by digestion of two peptides covering proinsulin residues 28 to 64. We studied their binding to purified HLA class I molecules and their recognition by T cells from diabetic patients. Peripheral blood mononuclear cells from 17 of 19 recent-onset and 12 of 13 long-standing type 1 diabetic patients produced IFN-gamma in response to proinsulin peptides as shown by using an ELISPOT assay. In most patients, the response was against several class I-restricted peptides. Nine peptides were recognized within the proinsulin region covering residues 34 to 61. Four yielded a high frequency of recognition in HLA-A1 and -B8 patients. Three peptides located in the proinsulin region 41-51 were shown to bind several HLA molecules and to be recognized in a high percentage of diabetic patients. PMID:16030147

  10. Generation of MHC class I-restricted cytotoxic T cell lines and clones against colonic epithelial cells from ulcerative colitis.

    Yonamine, Y; Watanabe, M; Kinjo, F; Hibi, T


    We established CTL lines and clones against colonic epithelial cells from PBLs of patients with ulcerative colitis by continuous stimulation with HLA-A locus-matched colonic epithelial cell lines. We developed a nonradioactive europium release cytotoxicity assay to detect CTLs. PBLs from 3 of 12 patients but not from any of 14 normal controls who shared at least one haplotype of HLA-A locus with two colonic epithelial cell lines, CW2 and ACM, showed increased cytotoxicity against these lines. Three CTL lines established from the PBLs of patients showed increased cytotoxicity against HLA-A locus-matched CW2 or ACM but not against matched lung or esophagus cell lines. The phenotypes of CTL lines were alpha beta-TCR+ CD3+ CD8+ CD16-. The CTL line MS showed increased cytotoxicity against freshly isolated colonic epithelial cells but not against cells with a different HLA-A locus. Two CTL clones were generated from MS and clone 3-2, expressing CD3+ CD8+ CD4- CD56-, showed high MHC class I-restricted cytotoxicity against the colonic epithelial cells. These results indicated that CTLs against colonic epithelial cells may contribute to epithelial cell damage in ulcerative colitis. PMID:10080107

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

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


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

  12. Neutrophil elastase enhances antigen presentation by upregulating human leukocyte antigen class I expression on tumor cells.

    Chawla, Akhil; Alatrash, Gheath; Philips, Anne V; Qiao, Na; Sukhumalchandra, Pariya; Kerros, Celine; Diaconu, Iulia; Gall, Victor; Neal, Samantha; Peters, Haley L; Clise-Dwyer, Karen; Molldrem, Jeffrey J; Mittendorf, Elizabeth A


    Neutrophil elastase (NE) is an innate immune cell-derived inflammatory mediator that we have shown increases the presentation of tumor-associated peptide antigens in breast cancer. In this study, we extend these observations to show that NE uptake has a broad effect on enhancing antigen presentation by breast cancer cells. We show that NE increases human leukocyte antigen (HLA) class I expression on the surface of breast cancer cells in a concentration and time-dependent manner. HLA class I upregulation requires internalization of enzymatically active NE. Western blots of NE-treated breast cancer cells confirm that the expression of total HLA class I as well as the antigen-processing machinery proteins TAP1, LMP2, and calnexin does not change following NE treatment. This suggests that NE does not increase the efficiency of antigen processing; rather, it mediates the upregulation of HLA class I by stabilizing and reducing membrane recycling of HLA class I molecules. Furthermore, the effects of NE extend beyond breast cancer since the uptake of NE by EBV-LCL increases the presentation of HLA class I-restricted viral peptides, as shown by their increased sensitivity to lysis by EBV-specific CD8+ T cells. Together, our results show that NE uptake increases the responsiveness of breast cancer cells to adaptive immunity by broad upregulation of membrane HLA class I and support the conclusion that the innate inflammatory mediator NE enhances tumor cell recognition and increases tumor sensitivity to the host adaptive immune response. PMID:27129972

  13. Salmonella enterica serovar Typhi live vector vaccines delivered intranasally elicit regional and systemic specific CD8+ major histocompatibility class I-restricted cytotoxic T lymphocytes.

    Pasetti, Marcela F; Salerno-Gonçalves, Rosangela; Sztein, Marcelo B


    We investigated the ability of live attenuated Salmonella enterica serovar Typhi strains delivered to mice intranasally to induce specific cytotoxic T-lymphocyte (CTL) responses at regional and systemic levels. Mice immunized with two doses (28 days apart) of Salmonella serovar Typhi strain Ty21a, the licensed oral typhoid vaccine, and genetically attenuated mutants CVD 908 (DeltaaroC DeltaaroD), CVD 915 (DeltaguaBA), and CVD 908-htrA (DeltaaroC DeltaaroD DeltahtrA) induced CTL specific for Salmonella serovar Typhi-infected cells in spleens and cervical lymph nodes. CTL were detected in effector T cells that had been expanded in vitro for 7 days in the presence of Salmonella-infected syngeneic splenocytes. A second round of stimulation further enhanced the levels of specific cytotoxicity. CTL activity was observed in sorted alphabeta+ CD8+ T cells, which were remarkably increased after expansion, but not in CD4+ T cells. CTL from both cervical lymph nodes and spleens failed to recognize Salmonella-infected major histocompatibility complex (MHC)-mismatched cells, indicating that the responses were MHC restricted. Studies in which MHC blocking antibodies were used showed that H-2L(d) was the restriction element. This is the first demonstration that Salmonella serovar Typhi vaccines delivered intranasally elicit CD8+ MHC class I-restricted CTL. The results further support the usefulness of the murine intranasal model for evaluating the immunogenicity of typhoid vaccine candidates at the preclinical level. PMID:12117906

  14. Immunization with a single major histocompatibility complex class I-restricted cytotoxic T-lymphocyte recognition epitope of herpes simplex virus type 2 confers protective immunity.

    Blaney, J E; Nobusawa, E; Brehm, M A; Bonneau, R H; Mylin, L M; Fu, T M; Kawaoka, Y; Tevethia, S S


    We have evaluated the potential of conferring protective immunity to herpes simplex virus type 2 (HSV-2) by selectively inducing an HSV-specific CD8(+) cytotoxic T-lymphocyte (CTL) response directed against a single major histocompatibility complex class I-restricted CTL recognition epitope. We generated a recombinant vaccinia virus (rVV-ES-gB498-505) which expresses the H-2Kb-restricted, HSV-1/2-cross-reactive CTL recognition epitope, HSV glycoprotein B residues 498 to 505 (SSIEFARL) (gB498-505), fused to the adenovirus type 5 E3/19K endoplasmic reticulum insertion sequence (ES). Mucosal immunization of C57BL/6 mice with this recombinant vaccinia virus induced both a primary CTL response in the draining lymph nodes and a splenic memory CTL response directed against HSV gB498-505. To determine the ability of the gB498-505-specific memory CTL response to provide protection from HSV infection, immunized mice were challenged with a lethal dose of HSV-2 strain 186 by the intranasal (i.n.) route. Development of the gB498-505-specific CTL response conferred resistance in 60 to 75% of mice challenged with a lethal dose of HSV-2 and significantly reduced the levels of infectious virus in the brains and trigeminal ganglia of challenged mice. Finally, i.n. immunization of C57BL/6 mice with either a recombinant influenza virus or a recombinant vaccinia virus expressing HSV gB498-505 without the ES was also demonstrated to induce an HSV-specific CTL response and provide protection from HSV infection. This finding confirms that the induction of an HSV-specific CTL response directed against a single epitope is sufficient for conferring protective immunity to HSV. Our findings support the role of CD8(+) T cells in the control of HSV infection of the central nervous system and suggest the potential importance of eliciting HSV-specific mucosal CD8(+) CTL in HSV vaccine design. PMID:9811690

  15. MHC ClassAntigen Presentation- Recently Trimmed and Well Presented

    Barry Flutter; Bin Gao


    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class Ⅰ molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class Ⅰ molecules assisted by several chaperone proteins to form trimeric complex. MHC class Ⅰ complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class Ⅰ expression must be carefully regulated. Many of the cellular components involved in antigen processing and class Ⅰ presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  16. MHC Class I Antigen Presentation- Recently Trimmed and Well Presented

    BarryFlutter; BinGao


    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class I molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class I molecules assisted by several chaperone proteins to form trimeric complex. MHC class I complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class I expression must be carefully regulated. Many of the cellular components involved in antigen processing and class I presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  17. Class II HLA antigens in multiple sclerosis.

    Miller, D H; Hornabrook, R W; Dagger, J; Fong, R


    HLA typing in Wellington revealed a stronger association of multiple sclerosis with DR2 than with DQw1. The association with DQw1 appeared to be due to linkage disequilibrium of this antigen with DR2. These results, when considered in conjunction with other studies, are most easily explained by the hypothesis that susceptibility to multiple sclerosis is influenced by multiple risk factors, with DR2 being an important risk factor in Caucasoid populations. PMID:2732726

  18. Examination of Serum Class I Antigen in Allograft Recipient Rats : Origin and control of serum class I antigen

    Sumimoto, Ryo; Fukuda, Yasuhiko; Shinomiya, Takahisa; Asahara, Toshimasa; Dohi, Kiyohiko


    We examined the appearance of DA type (RT1Aa) class I antigen in the serum of rats that had received isogeneic or allogeneic liver grafts (DA into DA, DA into LEW, PVG into DA, PVG into F1 hybrid (DAxPVG). Recipient LEW rats were given either one injection of the anti-CD8 mAb, OX-8, following thymectomy or anti-CD4 mAb (cocktail of OX-35 and OX-38) following thymectomy 3 days prior to liver grafting. We also tested the serum RT1Aa antigen titer of F1 (DAxPVG) recipients after PVG spleen trans...

  19. T cell retargeting with MHC class I-restricted antibodies: the CD28 costimulatory domain enhances antigen-specific cytotoxicity and cytokine production

    Willemsen, Ralph; Ronteltap, C.; Chames, P.; Debets, Reno; Bolhuis, Reinder


    textabstractT cells require both primary and costimulatory signals for optimal activation. The primary Ag-specific signal is delivered by engagement of the TCR. The second Ag-independent costimulatory signal is mediated by engagement of the T cell surface costimulatory molecule CD28 with its target cell ligand B7. However, many tumor cells do not express these costimulatory molecules. We previously constructed phage display derived F(AB), G8, and Hyb3, Ab-based receptors with identical specif...

  20. A gut-homing, oligoclonal CD4+ T cell population in severe-combined immunodeficient mice expressing a rearranged, transgenic class I-restricted alpha beta T cell receptor

    Reimann, J; Rudolphi, A; Spiess, S;


    We studied the peripheral T cell compartment of H-2b severe combined immunodeficient (scid) mice that express a transgenic (tg) alpha beta T cell receptor (TcR) specific for the H-Y (male) epitope presented by the H-2 class I Db molecule. Large populations of CD3+ NK1.1-TCR beta T+ T cells were...... present in spleen, mesenteric lymph nodes, peritoneal cavity, lamina propria and epithelial layer of the small and large intestine of 6- to 10-month-old, male and female tg scid mice. Only low numbers of CD3+ T cells were recovered from inguinal, popliteal, or axillary lymph nodes. We studied CD4+ T cells...... in these tg scid mice. CD4+ T cells were found in the peritoneal cavity, in the mesenteric lymph nodes and in the intraepithelial layer and lamina propria of the gut. All CD4+ T cells were CD44+ (i.e. showed evidence of antigen-driven differentiation) and expressed the tg V beta 8.2 TcR beta...

  1. Human leukocyte antigen-DO regulates surface presentation of human leukocyte antigen class II-restricted antigens on B cell malignancies

    Kremer, A.N.; Meijden, E.D. van der; Honders, M.W.; Pont, M.J.; Goeman, J.J.; Falkenburg, J.H.F.; Griffioen, M.


    Hematological malignancies often express surface HLA class II, making them attractive targets for CD4+ T cell therapy. We previously demonstrated that HLA class II ligands can be divided into DM-resistant and DM-sensitive antigens. In contrast to presentation of DM-resistant antigens, presentation o

  2. The role of class I histocompatibility antigens in the regulation of T-cell activation.

    Dasgupta, J D; Cemach, K; Dubey, D P; Yunis, E J; Amos, D. B.


    Class I major histocompatibility antigens in humans (HLA antigens) were found to participate in the regulation of T-cell activation and proliferation induced by phytohemagglutinin. W6/32, a monomorphic antibody directed against class I HLA-A,B,C antigens, significantly inhibited the phytohemagglutinin-induced cell proliferation of peripheral blood lymphocytes. Almost complete suppression of cell activation was achieved on a subfraction of peripheral blood lymphocytes enriched in Mo1+ monocyte...

  3. Class II-targeted antigen is superior to CD40-targeted antigen at stimulating humoral responses in vivo.

    Frleta, D; Demian, D; Wade, W F


    We examined the efficacy of using monoclonal antibodies to target antigen (avidin) to different surface molecules expressed on antigen presenting cells (APC). In particular, we targeted CD40 to test whether the "adjuvant" properties of CD40 signaling combined with targeted antigen would result in enhanced serologic responses. We targeted avidin to class II as a positive control and to CD11c as a negative control. These surface proteins represent an ensemble of surface molecules that signal upon ligation and that are expressed on professional APC, in particular dendritic cells (DC). We observed that targeting class II molecules on APC was superior to targeting CD40, or CD11c. However, CD40 and CD11c could function as targets for antigen bound monoclonal antibodies under certain conditions. Interestingly, inclusion of anti-CD40 mAb with the targeting anti-class II-targeted antigens negatively affects humoral response, suggesting that CD40 signaling under certain conditions may suppress processing and/or presentation of targeted antigen. PMID:11360928

  4. Relationship between the downregulation of HLA class I antigen and clinicopathological significance in gastric cancer

    Yu-Qing Shen; Jian-Qiong Zhang; Feng-Qing Miao; Jian-Min Zhang; Qin Jiang; Hao Chen; Xiang-Nian Shan; Wei Xie


    AIM: To discuss the expression of human leukocyte antigen (HLA) class I antigens in gastric cancer and correlate these with pathologic type and TNM stage.METHODS: The expression of HLA class I antigen was detected by immunohistochemistry in 185 specimens of gastric cancer, 20 gastric cancer specimens with lymphatic metastasis and 22 controls of normal gastric mucosa using four monoclonal antibodies.RESULTS: The expression of HLA class I antigen (B/C locus) was significantly downregulated in gastric cancer and in lymphatic metastasis than that in normal gastricmucosa (x2 = 7.712, P<0.05). The expression of other HLA class I antigens was also downregulated, but the change was slight. There was no relationship betweenthe downregulation of HLA class I antigen and that ofβ2m and LMP2. The expression of HLA class I (B/C locus) was statistically correlated with pathologic stage in gastric adenocarcinoma (x2= 4.164, P<0.05).CONCLUSION: The expression of HLA class I antigen (B/Clocus) was obviously downregulated in gastric cancer andin lymphatic metastasis. This abnormal expression wouldprovide the tumor cells with a way to avoid immunologicalrecognition.

  5. Selective transport of internalized antigens to the cytosol for MHC class I presentation in dendritic cells

    Rodriguez, A; Regnault, A; Kleijmeer, M; Ricciardi-Castagnoli, P; Amigorena, S


    In order for cytotoxic T cells to initiate immune responses, peptides derived from internalized antigens must be presented to the cytotoxic T cells on major histocompatibility complex (MHC) class I molecules. Here we show that dendritic cells, the only antigen-presenting cells that initiate immune r

  6. Association of class II human histocompatibility leukocyte antigens with rheumatic fever.

    Ayoub, E M; Barrett, D J; Maclaren, N K; Krischer, J P


    The association of class I and II HLA antigens with rheumatic fever and its manifestations was examined in 72 patients, including 48 blacks and 24 Caucasians. No significant association was found between class I antigens and rheumatic fever. In contrast, HLA-DR2 and HLA-DR4 phenotypes were encountered in a significantly higher frequency in black and Caucasian patients with rheumatic fever, respectively, compared with the control populations (P less than 0.005). The most significant associatio...

  7. Mechanistic insight into Type I restriction endonucleases.

    Youell, James; Firman, Keith


    Restriction and modification are two opposing activities that are used to protect bacteria from cellular invasion by DNA (e.g. bacteriophage infection). Restriction activity involves cleavage of the DNA; while modification activity is the mechanism used to "mark" host DNA and involves DNA methylation. The study of Type I restriction enzymes has often been seen as an esoteric exercise and this reflects some of their more unusual properties - non-stoichiometric (non-catalytic) cleavage of the DNA substrate, random cleavage of DNA, a massive ATPase activity, and the ability to both cleave DNA and methylate DNA. Yet these enzymes have been found in many bacteria and are very efficient as a means of protecting bacteria against bacteriophage infection, indicating they are successful enzymes. In this review, we summarise recent work on the mechanisms of action, describe switching of function and review their mechanism of action. We also discuss structural rearrangements and cellular localisation, which provide powerful mechanisms for controlling the enzyme activity. Finally, we speculate as to their involvement in recombination and discuss their relationship to helicase enzymes. PMID:22652768

  8. Expression of MHC class II antigens in human B-cell leukaemia and non-Hodgkin's lymphoma.

    Guy, K.; Krajewski, A S; Dewar, A E


    In this review we have summarized our experiences of serological analysis of MHC class II antigen expression in human B cell malignant disease. Cells from a large number of cases of B-cell chronic lymphocytic leukaemia (CLL) and non-Hodgkin's lymphoma (NHL) have been examined for expression of class II antigens. Using a number of monoclonal antibodies which in some cases are specific for class II subregion products (DP, DQ and DR), MHC class II antigens were detected by indirect immunofluores...

  9. Association of antigen processing machinery and HLA class I defects with clinicopathological outcome in cervical carcinoma

    Mehta, Akash M.; Jordanova, Ekaterina S.; Kenter, Gemma G; Ferrone, Soldano; Fleuren, Gert- Jan


    HLA class I loss is a significant mechanism of immune evasion by cervical carcinoma, interfering with the development of immunotherapies and cancer vaccines. We report the systematic investigation of HLA class I and antigen processing machinery component expression and association with clinical outcome. A tissue microarray containing carcinoma lesions from 109 cervical carcinoma patients was stained for HLA class I heavy chains, β2-microglobulin, LMP2, LMP7, LMP10, TAP1, TAP2, ERAP1, tapasin,...

  10. Cross-presentation of cell-associated antigens by MHC class I in dendritic cell subsets

    Enric eGutiérrez-Martínez


    Full Text Available Dendritic cells have the unique ability to pick up dead cells carrying antigens in tissue and migrate to the lymph nodes where they can cross-present cell-associated antigens by MHC class I to CD8+ T cells. There is strong in vivo evidence that the mouse XCR1+ dendritic cells subset acts as a key player in this process. The intracellular processes underlying cross-presentation remain controversial and several pathways have been proposed. Indeed, a wide number of studies have addressed the cellular process of cross-presentation in vitro using a variety of sources of antigen and antigen presenting cells. Here we review the in vivo and in vitro evidence supporting the current mechanistic models and disscuss their physiological relevance to the cross-presentation of cell-associated antigens by dendritic cells subsets

  11. Toward a network model of MHC class II-restricted antigen processing

    Laurence C Eisenlohr


    Full Text Available The standard model of Major Histocompatibility Complex class II (MHCII-restricted antigen processing depicts a straightforward, linear pathway: Internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4+ T cells (TCD4+. Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while proposing that MHCII processing be thought of less in terms of discrete pathways and more in terms of a network whose major and minor conduits are variable depending upon many factors, including the epitope, the nature of the antigen, the source of the antigen, and the identity of the antigen-presenting cell.

  12. Typing of HLA class II and class I antigens using PHA-activated, IL-2-propagated T lymphocytes.

    Leshem, B; Cohen, I; Sherman, L; Brautbar, C; Kedar, E


    We describe here a simple procedure, by which HLA class II antigens can be accurately and reliably identified in those patients where there is minimal or absent expression of HLA-DR,DQw antigens on B cells, or when the total number of leukocytes recovered from the patients do not permit reliable typing. Ficoll-Hypaque-separated peripheral blood mononuclear leukocytes, fresh or cryopreserved, were activated by PHA and then propagated in IL-2-containing medium until enough cells for typing were obtained (usually 7-14 days). At this stage, the cultured cells were shown to be primarily T cells (greater than 90% CD3+). Since the activated T cells propagate in the presence of IL-2, even a small number (10(4] of fresh or cryopreserved patients' cells suffice for this protocol. To date we have been able to successfully HLA-DR,DQw type 34/34 bone marrow transplantation candidates and 12/12 long-term dialysis patients, who were untypable using fresh cells. HLA-DR,DQw antigens on activated T cells from normal individuals were identical to those found on their uncultured B cells. In addition, class I antigens that were undetectable on the uncultured cells of one patient could be identified on activated T cells. The HLA antigens identified on the patients' activated T cells were confirmed by phenotypic analysis of cells from family members. PMID:3260612

  13. MHC class II antigen expression was different from MHC class I antigen expression in irradiated and recovering rat thymus

    We exposed rats to a heavy, but sublethal, dose of X-radiation that was calculated as the maximum that left them alive. Immediately after irradiation the rats lost body and thymus weight. The number of thymocytes decreased and the structure of the thymus was destroyed. The thymus weights then increased rapidly for a few days from day 7 followed by a slower increase. Immunohistochemically, the recovery of major histocompatibility complex (MHC) class II-positive cells in the thymus was slower than that of MHC class I-positive cells. Recovery of MHC class II-positive and ED1-positive cells in the thymus was slow, especially in the medulla. Thymus structure appeared similar to normal control animals on day 14, although the number of MHC class II- and ED1-positive cells in the medulla was lower than that of controls even 21 days after radiation exposure. The delay in recovery of MHC class II-positive stromal cells might affect the regeneration of thymocyte subpopulations after irradiation. (author)

  14. Antigen

    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 ...

  15. Restricted dog leucocyte antigen (DLA) class II haplotypes and genotypes in Beagles

    Soutter, Francesca; Kennedy, Lorna J; Ollier, William E R; Solano-Gallego, Laia; Catchpole, Brian


    Beagles are commonly used in vaccine trials as part of the regulatory approval process. Genetic restriction within this breed and the impact this might have on vaccine responses are rarely considered. This study was designed to characterise diversity of dog leucocyte antigen (DLA) class II genes in a breeding colony of laboratory Beagles, whose offspring are used in vaccine studies. DLA haplotypes were determined by PCR and sequence-based typing from genomic DNA extracted from blood. Breeding...

  16. Expression of major histocompatibility complex class I and class II antigens in human Schwann cell cultures and effects of infection with Mycobacterium leprae.

    Samuel, N M; Mirsky, R; Grange, J M; Jessen, K R


    Recent experiments on rats have raised the possibility that Schwann cells can present antigens to T lymphocytes. We have investigated whether this mechanism might be relevant in leprosy by determining under what conditions human Schwann cells express class I and class II antigens, and whether infection with Mycobacterium leprae affects this expression. The distribution of these antigens was examined on human Schwann cells in dissociated cell cultures derived from human fetal peripheral nerves. We find that both Schwann cells and fibroblastic cells in these cultures normally express class I antigens but not class II antigens. When Schwann cells are infected with live Mycobacterium leprae for 48 h, 73% of Schwann cells phagocytose the bacteria. Mycobacterium leprae prevents 3H-thymidine incorporation into cultured human Schwann cells, but does not affect class I expression in these cells. Treatment of normal and Mycobacterium leprae infected cultures with gamma-interferon for 72 h induces class II expression on most Schwann cells but not on the majority of fibroblastic cells. The fact that human Schwann cells infected with Mycobacterium leprae can be induced by gamma-interferon to express class II antigens suggests that they may be able to present Mycobacterium leprae antigens to T lymphocytes and thus initiate immune responses against the bacteria. We suggest that a failure of this response, such as that seen within nerve trunks in lepromatous leprosy, is caused by deficient class II expression on Schwann cells. This deficiency in class II expression, in turn, may be caused by the reduced gamma-interferon production characteristic of lepromatous leprosy. PMID:3115648

  17. Human epidermal Langerhans cells cointernalize by receptor-mediated endocytosis "nonclassical" major histocompatibility complex class I molecules (T6 antigens) and class II molecules (HLA-DR antigens).

    Hanau, D.; Fabre, M.; Schmitt, D A; Garaud, J C; Pauly, G; Tongio, M M; Mayer, S.; Cazenave, J. P.


    HLA-DR and T6 surface antigens are expressed only by Langerhans cells and indeterminate cells in normal human epidermis. We have previously demonstrated that T6 antigens are internalized in Langerhans cells and indeterminate cells by receptor-mediated endocytosis. This process is induced by the binding of BL6, a monoclonal antibody directed against T6 antigens. In the present study, using a monoclonal antibody directed against HLA-DR antigens, on human epidermal cells in suspension, we show t...

  18. Tracking antigen-specific CD8+ T cells in the rat using MHC class I multimers.

    Duplan, Valérie; Suberbielle, Elsa; Napper, Catherine,; Joly, Etienne; Saoudi, Abdelhadi; Gonzalez-Dunia, Daniel


    Studies of the quantitative and qualitative aspects of anti-microbial, anti-tumoral or autoreactive immune responses have been greatly facilitated by the possibility to stain antigen-specific CD8(+) T cells using fluorescently labeled multimeric major histocompatibility complex (MHC) class I/peptide complexes. So far, this technology has been developed for human and mouse, but not yet in the rat. Here, we describe the generation of the first rat MHC multimer. We produced a rat RT1(l) Pro5 MHC...

  19. Lack of association between parenchymal neurocysticercosis and HLA Class I and Class II antigens

    Eni Picchioni Bompeixe


    Full Text Available Neurocysticercosis, caused by encysted larvae of the tapeworm Taenia solium, is the most common infection of the central nervous system and a major public health problem in many countries. Prevalence in the region of Curitiba, located in the southern Brazilian State of Paraná, is one of the highest in the world. The genetics of host susceptibility to neurocysticercosis (NCC is still obscure. To investigate if major histocompatibility complex (MHC genes influence individual susceptibility to NCC, we performed a case-control association analysis. Fifty-two Caucasoid patients and 149 matched controls were typed for antigens of the HLA-A, B, C, DR and DQ loci. All patients had computerized tomography and clinical features compatible with parenchymal NCC. Indirect immunofluorescence of cerebrospinal fluid showed that 19 (37% of the patients presented anti-cysticercus antibodies at titers ³ 1:10. Frequencies of HLA specificities in the whole group of patients and in the subgroup with antibodies in cerebrospinal fluid were compared to those of the control group. No significant difference was found. These results do not support the hypothesis of HLA gene participation in susceptibility to parenchymal neurocysticercosis.A neurocisticercose, causada pelo cisticerco, a larva do cestóide Taenia solium, é a infecção mais comum do sistema nervoso central e constitui importante problema de saúde pública em muitos países. A sua prevalência na região de Curitiba, localizada no Estado do Paraná, foi estimada em 9%, situando-se entre as mais elevadas do mundo. Os aspectos genéticos de suscetibilidade à neurocisticercose (NCC ainda são pouco conhecidos. Com o objetivo de investigar se genes do MHC influenciam a suscetibilidade individual à NCC, realizamos uma análise de associação caso-controle. Cinqüenta e dois pacientes caucasóides e 149 indivíduos-controle pareados foram tipados para antígenos dos locos HLA-A, B, C, DR e DQ. Todos os

  20. Expression of major histocompatibility complex class II antigens in porcine leptospiral nephritis.

    Radaelli, E; Del Piero, F; Aresu, L; Sciarrone, F; Vicari, N; Mattiello, S; Tagliabue, S; Fabbi, M; Scanziani, E


    Class II major histocompatibility complex (MHCII) is required for the presentation of antigens to CD4 helper T cells. During nephritis, not only primary antigen presenting cells such as histiocytes and lymphocytes, but also cytokine-stimulated tubular epithelial cells express MHCII. Leptospirosis in fattening pigs is characterized by several degrees of nephritis, from absence of lesions to severe multifocal tubulo-interstitial inflammation. Renal tissue from 20 8-month-old pigs with spontaneous nephritis and 6 control pigs without renal lesions were investigated for leptospirosis by indirect immunohistochemistry (IHC) and polymerase chain reaction (PCR). IHC for MHCII also was performed on renal samples. Serum samples were tested for different serovars of Leptospira interrogans. Control pigs were free of interstitial nephritis and negative for leptospirosis by all tests. In pigs with nephritis, serology was positive for serovar Pomona in 19/20 pigs. In 16 of these 19 pigs, leptospiral renal infection was confirmed by PCR and/or indirect IHC. Nephritic lesions were classified histologically into perivascular lymphocytic (4 pigs), lymphofollicular (6 pigs), lymphohistiocytic (8 pigs), and neutrophilic (2 pigs) pattern. MHCII expression by histiocytes and lymphocytes was observed in all lesions. Prominent MHCII expression in regenerating tubular epithelium was observed in lymphofollicular and lymphohistiocytic nephritis. No tubular colocalization between leptospiral and MHCII antigen was observed. Results suggest that during leptospiral nephritis, MHCII contributes to the intensity of the inflammatory response. Furthermore de novo MHCII expression in regenerating tubules may play a role in the defence mechanism against leptospiral tubular colonization. PMID:19179617

  1. Class specific antibody responses to newborn larva antigens during Trichinella spiralis human infection

    Mendez-Loredo B.


    Full Text Available A follow-up study of the class antibody responses to newborn larva (NBL antigens in individuals involved in an outbreak of human trichinellosis was carried out by ELISA assays. The data showed that similar kinetics of antibody responses of different magnitude developed in trichinellosis patients; it was low by week 3, a peak raised by week 5 and decreased from week 7 up to the end of the study. The IgA-ELISA assay was the most sensitive and specific while the IgM was the least sensitive and specific. IgA antibodies to NBL antigens were detected in 80 % of patients while IgE, IgG and IgM responses were observed in 44, 31 and 19 % of the patients by week 3, respectively. From weeks 5 to 7, IgA antibodies were found in 89 to 100 % of the patients while lower percentages (0-82 % were found for the other isotypes. Reactivity of IgA, IgE, IgG and IgM to NBL antigens decreased from week 37 to 57 after infection (0-38 %. These results suggest that detection of IgA antibodies may be useful for early diagnosis and epidemiological studies in human trichinellosis.

  2. Human leukocyte antigen class II susceptibility conferring alleles among non-insulin dependent diabetes mellitus patients

    To determine the frequency of Human Leukocyte Antigen (HLA) class II susceptibility conferring alleles among type 2 Diabetes mellitus patients, in comparison with healthy controls. Cross-sectional comparative study. Patients with non-insulin dependent Diabetes mellitus meeting World Health Organization criteria were studied. These were compared with age and gender matched healthy control subjects. For each subject (patients as well as controls), DNA was extracted from ethylene diamine tetra-acetate sample and HLA class II DRB1 typing was carried out at allele group level (DRB1*01-DRB1*16) by sequence specific primers. Human leukocyte antigen DRB1 type was determined by agarose gel electrophoresis and results were recorded. Frequencies were determined as number of an allele divided by total number of alleles per group; p-value was computed using Pearson's chi-square test. Among the 100 patients, there were 63 males and 37 females with 68 controls. A total of 13 different HLA DRB1 alleles were detected, with DRB1*15 being the commonest in both the groups. The allele DRB1*13 had statistically significant higher frequency in patient group as compared to controls (p 0.005). HLA DRB1*13 was found with a significantly increased frequency in non-insulin dependent Diabetes mellitus. (author)

  3. Regulation of T cell response to leishmania antigens by determinants of histocompatibility leukocyte class I and II molecules

    Bacellar O.


    Full Text Available It has been shown that HLA class I molecules play a significant role in the regulation of the proliferation of T cells activated by mitogens and antigens. We evaluated the ability of mAb to a framework determinant of HLA class I molecules to regulate T cell proliferation and interferon gamma (IFN-g production against leishmania, PPD, C. albicans and tetanus toxoid antigens in patients with tegumentary leishmaniasis and healthy subjects. The anti-major histocompatibility complex (MHC mAb (W6/32 suppressed lymphocyte proliferation by 90% in cultures stimulated with aCD3, but the suppression was variable in cultures stimulated with leishmania antigen. This suppression ranged from 30-67% and was observed only in 5 of 11 patients. IFN-g production against leishmania antigen was also suppressed by anti-HLA class I mAb. In 3 patients IFN-g levels were suppressed by more than 60%, while in the other 2 cultures IFN-g levels were 36 and 10% lower than controls. The suppression by HLA class I mAb to the proliferative response in leishmaniasis patients and in healthy controls varied with the antigens and the patients or donors tested. To determine whether the suppression is directed at antigen presenting cells (APCs or at the responding T cells, experiments with antigen-primed non-adherent cells, separately incubated with W6/32, were performed. Suppression of proliferation was only observed when the W6/32 mAb was added in the presence of T cells. These data provide evidence that a mAb directed at HLA class I framework determinants can suppress proliferation and cytokine secretion in response to several antigens.

  4. Persistence of hepatitis C virus in a white population: associations with human leukocyte antigen class 1.

    Fanning, Liam J


    The aim of this study was to define novel associations between human leukocyte antigen (HLA) class 1 alleles and persistence or clearance of the hepatitis C virus (HCV) in a white population. All individuals in the study were seropositive for anti-HCV antibodies. Viral status was determined by the Roche HCV Amplicor test. HLA-A, -B, -C allelic group profile was molecularly defined by reverse line probe hybridization. The strongest individual allelic group associations with persistent HCV infection were HLA A*11 (p = 0.044) and Cw*04 (p = 0.006). However, only the HLA C*04 association survived correction for multiple comparisons. Further analysis of alleles in linkage with HLA Cw*04 revealed that the haplotype HLA A*11, Cw*04 was present in 11 individuals, 10 of whom were viremic (p = 0.05). No gene dosage effect was observed. No association between HLA class 1 allelic groups and aviremia and virus load was evident in this white population. HLA B*44 is associated with low virus load in human immunodeficiency virus disease, but this association was not evident in this HCV-infected population. Novel HLA class 1 alleles associated with persistence of HCV have been identified.

  5. Seasonal Evaluation of Antigenic Bacterial Infections Among Working Class in the Inner City of Houston

    Ebere C. Anyanwu


    Full Text Available This paper evaluates the monthly, quarterly, and seasonal variation of antigenic bacterial infections among the working class in the inner city of Houston using the Wellcogen Rapid Test methods. One of the aims was to demonstrate how this method could be used effectively in screening patients at risk and preventing the spread of antigenic bacteria such as Streptococcus pneumoniae, Haemophilus influenzae b, Streptococcus (Strep b, and Neisseria meningitidis (mainly group c and b. A total of 2,837 patients were screened for bacterial infections; 908 (32% were male and 1,929 (68% were female. The age range was between 2 and 70 years. Of the total group, 356 (12.5% patients were positive; 203 (57% were female while 153 (43% were male (male/female ratio of 1:1.3. Medically underserved and immune suppressed populations are the most affected by these bacterial infections. Blacks are the most affected (48% compared to Native Americans (1%, but children under 10 years of age have the highest incidence. This research showed, in addition, that the Wellcogen Rapid Tests are effective (356 cases identified for a rapid screening of infectious bacteria. Explanation for these results was probably due to poor living conditions, poor hygiene, and viral immune suppression in adults and immature immune systems in neonates and children under 10 years of age.

  6. Allele-Independent Turnover of Human Leukocyte Antigen (HLA) Class Ia Molecules.

    Prevosto, Claudia; Usmani, M Farooq; McDonald, Sarah; Gumienny, Aleksandra M; Key, Tim; Goodman, Reyna S; Gaston, J S Hill; Deery, Michael J; Busch, Robert


    Major histocompatibility complex class I (MHCI) glycoproteins present cytosolic peptides to CD8+ T cells and regulate NK cell activity. Their heavy chains (HC) are expressed from up to three MHC gene loci (human leukocyte antigen [HLA]-A, -B, and -C in humans), whose extensive polymorphism maps predominantly to the antigen-binding groove, diversifying the bound peptide repertoire. Codominant expression of MHCI alleles is thus functionally critical, but how it is regulated is not fully understood. Here, we have examined the effect of polymorphism on the turnover rates of MHCI molecules in cell lines with functional MHCI peptide loading pathways and in monocyte-derived dendritic cells (MoDCs). Proteins were labeled biosynthetically with heavy water (2H2O), folded MHCI molecules immunoprecipitated, and tryptic digests analysed by mass spectrometry. MHCI-derived peptides were assigned to specific alleles and isotypes, and turnover rates quantified by 2H incorporation, after correcting for cell growth. MHCI turnover half-lives ranged from undetectable to a few hours, depending on cell type, activation state, donor, and MHCI isotype. However, in all settings, the turnover half-lives of alleles of the same isotype were similar. Thus, MHCI protein turnover rates appear to be allele-independent in normal human cells. We propose that this is an important feature enabling the normal function and codominant expression of MHCI alleles. PMID:27529174

  7. Prevalence of G class antibodies to antigens of lyme disease causes in dogs in Vojvodina, Serbia

    Potkonjak Aleksandar


    Full Text Available Lyme disease is a multisystemic disease, zoonotic in nature, caused by the Borrelia burgdorferi sensu lato complex. In the continent of Europe, these spirochetes are predominantly transmitted by ticks of the genus Ixodes. Small mammals and birds have particular significance as reservoirs of the cause of lyme disease. The objective of these epidemiological investigations was to determine the value of IgG seroprevalence to Borrelia burgdorferi and to secure the geographic distribution of seropositive dogs in Vojvodina. The investigations covered 135 dogs that were not vaccinated against lyme disease. The indirect ELISA test was used to determine IgG prevalence to Borrelia burgdorferi antigens. Reactive blood serums of dogs were tested again using the rapid immunochromatographic and immunoblot test. A seroprevalence of G class antibodies to antigens of lyme disease causes of 8.1% (11/135 was established in the examined dog population of Vojvodina. The biggest number of positive results was recorded for the South Bačka District. The presented value for the seroprevalence of anti-Borrelia burgdorferi antibodies in the dog population indicates the exhistence of a significant risk of humans becoming infected with the cause of lyme disease in Vojvodina.

  8. Role of HLA class I antigens in the development of psoriatic arthritis and its clinical presentation

    Irina Aleksandrovna Troshkina


    Full Text Available Objective: to investigate the association of HLA Class I antigens with the predisposition to psoriatic arthritis (PsA and the severity and types of articular syndrome in PsA. Subjects and methods. The investigation enrolled 99 patients (56 females and 43 males aged 43.5+13 years with PA with a median duration of 2 (range 0.8-10 years. An oligoarthritic type was observed in 28 patients, polyarthritic, distal, and spondyloarthritic types were present in 28, 39, and 10 patients, respectively. Two patient groups were formed according to the age at onset of psoriasis: 1 71 patients aged less than 40 years and 2 23 patients aged over 40 years. Results. As compared with the control group, the patients with PsA were found to have a higher frequency of HLA-B13 (odds ratio [OR] 2.72; p < 0.004, HLA-В16 (OR 3.95; p < 0.0001, and HLA-B27 (OR 3.2; p < 0.003. There was an association of the types of joint injury with HLA antigens: the distal type with HLA-B13 (OR 3.38; p < 0.02 and HLA-В16 (OR 3.95; p < 0.01, the polyarthritic type with HLA-В16 (OR 5.90; p < 0.0001 and HLA-B27 (OR 3.26; p < 0.01, and the spondyloarthritic type with HLA-B27 (OR 6.32; p < 0.001. The young onset of psoriasis was associated with HLA-B13 (OR 3.29; p < 0.001. The detection rate of the B38 antigen (the subtype of HLA-B16 was higher in all X-ray stages of PsA and was 16.4% in Stages I-IIA, 25% in Stage IIB, and 40.9% in Stages III-IV versus 8.7% in the control group, the magnitude of the association being increased with the higher degree of joint destruction. Conclusion. The detailed analysis of the investigation revealed that HLA system antigens were differently involved in the development of PsA and clinical types of articular syndrome.

  9. HLA class II antigens and haplotypes associated with susceptibility of leukemias and myelodysplastic syndrome

    Vojvodić Svetlana


    Full Text Available Genetical and environmental factors play an interactive role in the development of acute and chronic leukemias. HLA antigens have been considered as possible genetic risk factors. The aim of this work was to investigate a possible association between HLA class II polymorphisms and leukemias and myelodysplastic syndrome. In the present study we investigated HLA class II antigens, DR/DQ and DR51/DR52/DR53 haplotypes in 100 patients: 7 suffering from myelodysplastic syndrome (MDS,37 from acute lymphoblastic leukemia(ALL,32 from acute myeloid leukemia (AML and 24 from chronic myeloid leukemia(CML. A panel of 210 healthy unrelated individuals of the same origin, from Vojvodina, served as controls. HLA phenotyping was performed by two color fluorescence method. In patients suffering from MDS was found a positive association with DR7(RR=2.598,EF=0.175 and DQ7(3(RR=4.419, EF=0.632, while negative association was found for DR15(2(RR=0.405, PF=0.172 and DQ6(1 (RR=0.889, PF=0,936.Positive association was found in the group of patients with ALL for DR7(RR=2.391,EF=0.688 and DQ2(RR=1.62, EF=0.15,while negative association was found with DQ5(1(RR=0.075, PF=0.324. In the group of patients with AML, there were positive associations with DR11(5(RR=1.732,EF=0.211,DQ2(RR= 1.594, EF=0.151 and DQ7(3 (RR=2.547,EF=0.266,while possible protective antigen was DQ5(1 (RR=0.107,RF=0.701. Higher RR than 1 and EF>0.15, in patients suffering from CML was found for DQ6(1(RR=1.661,EF=0.232, while negative association was found for DR4 (RR=0.182,PF=0.155.Possible protective haplotype in this study was DR3DQ8(3 for patients suffering from AML(RR=0.007, PF=0.501.The distribution of DR53-DR53 haplotypes showed significant difference in male patients with ALL(6% vs 0.09%, while DR52-DR52 haplotype was significantly less frequent in male patients with CML (4% vs 20.47% and female patients with MDS (1% vs 18.57%, respectively, in comparison to controls. We deduced that DR7 antigen in


    "A. Aghamohammadi


    Full Text Available Common variable immunodeficiency (CVID is a heterogeneous heritable disease characterized by arrest in B cell differentiation. An association between CVID and two HLA haplotypes, haplotype I (HLA-A1, HLA-B8, HLA-DR3 and haplotype II (HLA-A29, HLA-B44, HLADR7has been previously documented. In the present study, we have attempted to find an association between susceptibility to CVID and HLA class I and II antigens in Iranian population. Seventeen Iranian patients with CVID (mean age 17, range 3-28 years; 12 male and 5 female, including two couples of brothers and 100 healthy controls were studied. All subjects were typed for HLA class 1, and 12 patients and all controls were typed for HLA class II, using microdroplet lymphocytotoxicity technique. Out of 12 CVID patients typed for HLA-DR and DQ specificities, five patients presented DR-1, which showed an increased frequency in patient (41.6% vs. 12% in controls, and 3 presented DQ-2, which also showed an increased frequency (25% vs. 4% in controls, both of which reached statistical significance (P = 0.018 and P = 0.026, respectively. HLA-DR10 was present in 2 patients (16.6%, which was markedly more frequent compared to controls, but this difference was not significant statistically. Our results suggest that HLA-DR1 and DQ-2 may contribute to susceptibility to CVID. We did not find any significant association between HLA-A1, B8 and DR3 that has been previously reported to be associated with CVID.

  11. Targeting tumor-associated antigens to the MHC class I presentation pathway.

    Gross, G; Margalit, A


    There is little doubt that cytotoxic T lymphocytes (CTLs) can kill tumor cells in-vivo. However, most CTL-inducing immunization protocols examined so far in cancer patients have yielded only limited clinical benefits, underscoring the urge to improve current approaches for the effective induction of tumor-reactive CTLs. The tumor side of the immunological frontline is armed with large masses, high mutability and an arsenal of immune evasion and suppression mechanisms. Accordingly, the confronting CTLs should come in large numbers, recognize an assortment of MHC class I (MHC-I) bound tumor-associated peptides and be brought into action under effective immunostimulatory conditions. Naïve CTLs are activated to become effector cells in secondary lymphoid organs, following their productive encounter with MHC-I-bound peptides at the surface of dendritic cells (DCs). Therefore, many cancer vaccines under development focus on the optimization of peptide presentation by DCs at this critical stage. The elucidation of discrete steps and the subsequent identification of inherent bottlenecks in the MHC-I antigen presentation pathway have fueled elaborate efforts to enhance vaccine efficacy by the rational targeting of proteins or peptides, formulated into these vaccines, to this pathway. Protein- and gene-based strategies are accordingly devised to deliver tumor-associated peptides to selected cellular compartments, which are essential for the generation of functional CTL ligands. Many of these strategies target the conventional, endogenous route, while others harness the unique pathways that enable DCs to present exogenous antigens, known as cross-presentation. Here we dissect the intricate machinery that produces CTL ligands and examine how knowledge-based cancer vaccines can target the sequence of workstations, biochemical utensils and molecular intermediates comprising this production line. PMID:17584150

  12. MHC-I-restricted epitopes conserved among variola and other related orthopoxviruses are recognized by T cells 30 years after vaccination

    Tang, Sheila Tuyet; Wang, M.; Lamberth, K.; Harndahl, M.; Dziegiel, M.H.; Claesson, M.H.; Buus, Søren; Lund, Ole


    It is many years since the general population has been vaccinated against smallpox virus. Here, we report that human leukocyte antigen (HLA) class I restricted T cell epitopes can be recognized more than 30 years after vaccination. Using bioinformatic methods, we predicted 177 potential cytotoxic T...... lymphocyte epitopes. Eight epitopes were confirmed to stimulate IFN-gamma release by T cells in smallpox-vaccinated subjects. The epitopes were restricted by five supertypes (HLA-A1, -A2, -A24 -A26 and -B44). Significant T cell responses were detected against 8 of 45 peptides with an HLA class I affinity of...... K(D) less than or equal to 5 nM, whereas no T cell responses were detected against 60 peptides with an HLA affinity of K(D) more than 5 nM. All epitopes were fully conserved in seven variola, vaccinia and cowpox strains. Knowledge of the long-term response to smallpox vaccination may lead to a...

  13. A modern approach for epitope prediction: identification of foot-and-mouth disease virus peptides binding bovine leukocyte antigen (BoLA) class I molecules

    Major histocompatibility complex (MHC) class I molecules regulate adaptive immune responses through the presentation of antigenic peptides to CD8positive T-cells. Polymorphisms in the peptide binding region of class I molecules determine peptide binding affinity and stability during antigen presenta...

  14. Alternative Ii-independent antigen-processing pathway in leukemic blasts involves TAP-dependent peptide loading of HLA class II complexes

    M.M. van Luijn; M.E.D. Chamuleau; M.E. Ressing; E.J. Wiertz; S. Ostrand-Rosenberg; Y. Souwer; A. Zevenbergen; G.J. Ossenkoppele; A.A. van de Loosdrecht; S.M. Ham


    During HLA class II synthesis in antigen-presenting cells, the invariant chain (Ii) not only stabilizes HLA class II complexes in the endoplasmic reticulum, but also mediates their transport to specialized lysosomal antigen-loading compartments termed MIICs. This study explores an alternative HLA cl

  15. Cross-Reaction between the Crude Hydatid Cyst Fluid Antigens of Human and Animals Origin in Response to Human IgG Class and Subclasses

    Afra Khosravi


    Full Text Available The current work aimed to evaluate the cross-reactivity of human immune sera against crude hydatid fluid antigens of sheep, human, mouse, cattle, as well as B fraction of cystic fluid antigen. 30 balb/c mice were infected with sheep hydatid cyct fluid antigen containing protoscolex after the viability of these protoscolices was assessed. ANOVA was used to test the difference of themean of optical density (OD values among case and control groups. The highest human IgG class antibody was against antigen B (0.93 and the lowest against cattle HCF antigen (0.32. The differences between responses to these antigens were statistically significant (P<0.001. The sensitivity and specificity of ELISA test used for evaluating the responses of human total IgG to different hydatid cyst fluid (HCF antigens among the case and control groups were 100 and 95.8%, respectively. Cross-reaction of human IgG class and subclasses responses was found almost for all the antigens with the best reaction against human and cattle (HCF antigens and antigen B using a ratio of mean OD value to each antigen divided by the cut-off point value for the same antigen. Human sera showed a considerable cross-reactivity against all antigens by using ELISA.

  16. MHC class I is functionally associated with antigen receptors in human T and B lymphomas

    Pedersen, Anders Elm; Jacoby, B F; Skov, S;


    We have studied the antibody-induced effect of cross-linking the major histocompatibility complex class I (MHC-I) in human T leukemic cells (Jurkat) and human B lymphoma cells (Solubo, Burkitts lymphoma) on intracellular [Ca2+]i levels. The increase in [Ca2+]i after MHC-I cross-linking in Jurkat...... lines the increase in [Ca2+]i after MHC-I cross-linking caused upregulation of CD69, an early marker of activation. When studying the effect of MHC-I cross-linking on the TCR- and B cell antigen receptor (BCR)- mediated increase in [Ca2+]i, respectively, we observed that MHC-I had a costimulatory effect......, respectively, were positively correlated with the level of MHC-I expressed on the cell surface. These observations suggest two different roles in signal transduction for the MHC-I molecules in the T and B cells studied. First, by themselves MHC-I complexes are able to induce activation of intracellular second...

  17. Mixed enzyme-linked immunosorbent assay (MELISA) for HLA class I antigen: a plasma membrane marker.

    Bjerrum, O W; Borregaard, N


    This study introduces a simple, reproducible assay for HLA class I antigen using antibodies against beta 2-microglobulin and the heavy chain on HLA. The sandwich technique was named mixed enzyme-linked immunosorbent assay (MELISA), and was designed for identification of plasma membranes in neutrophil subcellular fractions. The subcellular localization of HLA was identical to that of other plasma membrane markers, [3H]concanavalin A and detergent-independent alkaline phosphatase, and was unchanged by stimulation of cells by weak and strong secretagogues. In addition to the presence as part of the HLA complex in the plasma membrane uncomplexed beta 2-microglobulin is present in the specific granules of neutrophils. However, the release of beta 2-microglobulin from intact neutrophils stimulated with formyl-methionylleucylphenylalanine was much higher than could be explained by exocytosis of specific granules. Subcellular fractionation studies demonstrated that beta 2-microglobulin is localized in fractions characterized by latent alkaline phosphatase and released from this novel secretory compartment in response to stimulation with formyl-methionylleucylphenylalanine. PMID:2181625

  18. JC Polyomavirus Infection Is Strongly Controlled by Human Leucocyte Antigen Class II Variants

    Sundqvist, Emilie; Buck, Dorothea; Warnke, Clemens;


    JC polyomavirus (JCV) carriers with a compromised immune system, such as in HIV, or subjects on immune-modulating therapies, such as anti VLA-4 therapy may develop progressive multifocal leukoencephalopathy (PML) which is a lytic infection of oligodendrocytes in the brain. Serum antibodies to JCV...... mark infection occur only in 50-60% of infected individuals, and high JCV-antibody titers seem to increase the risk of developing PML. We here investigated the role of human leukocyte antigen (HLA), instrumental in immune defense in JCV antibody response. Anti-JCV antibody status, as a surrogate for......, the DQB1*06:03 haplotype was positively associated with JCV sero-status, in Scandinavian MS cases (OR = 1.63, p = 0.006), and controls (OR = 2.69, p = 1×10(-5)). The German dataset confirmed these findings (OR = 0.54, p = 1×10(-4) and OR = 1.58, p = 0.03 respectively for these haplotypes). HLA class...

  19. MHC Class II and Non-MHC Class II Genes Differentially Influence Humoral Immunity to Bacillus anthracis Lethal Factor and Protective Antigen

    Judith A. James


    Full Text Available Anthrax Lethal Toxin consists of Protective Antigen (PA and Lethal Factor (LF, and current vaccination strategies focus on eliciting antibodies to PA. In human vaccination, the response to PA can vary greatly, and the response is often directed toward non-neutralizing epitopes. Variable vaccine responses have been shown to be due in part to genetic differences in individuals, with both MHC class II and other genes playing roles. Here, we investigated the relative contribution of MHC class II versus non-MHC class II genes in the humoral response to PA and LF immunization using three immunized strains of inbred mice: A/J (H-2k at the MHC class II locus, B6 (H-2b, and B6.H2k (H-2k. IgG antibody titers to LF were controlled primarily by the MHC class II locus, whereas IgG titers to PA were strongly influenced by the non-MHC class II genetic background. Conversely, the humoral fine specificity of reactivity to LF appeared to be controlled primarily through non-MHC class II genes, while the specificity of reactivity to PA was more dependent on MHC class II. Common epitopes, reactive in all strains, occurred in both LF and PA responses. These results demonstrate that MHC class II differentially influences humoral immune responses to LF and PA.

  20. Antigen presentation by liposomes bearing class II MHC and membrane IL-1.

    Bakouche, O; LACHMAN, L.B.


    Liposomes containing membrane IL-1, Iak, and the antigen conalbumin were evaluated as "synthetic antigen presenting cells." The role of these three molecules in macrophage-T cell interaction was studied by testing their ability to induce the proliferation of a T-cell clone specific to conalbumin (the D10 cell line) or immune spleen cells sensitized three times in vivo with conalbumin. In the latter case, splenic macrophages were eliminated by adherence and a lysomotropic agent. The antigen co...

  1. Mass spectrometry of human leukocyte antigen class I peptidomes reveals strong effects of protein abundance and turnover on antigen presentation

    Bassani-Sternberg, Michal; Pletscher-Frankild, Sune; Jensen, Lars Juhl; Mann, Matthias


    HLA class I molecules reflect the health state of cells to cytotoxic T cells by presenting a repertoire of endogenously derived peptides. However, the extent to which the proteome shapes the peptidome is still largely unknown. Here we present a high-throughput mass-spectrometry-based workflow that...

  2. Regressing and progressing metastatic lesions: resistance to immunotherapy is predetermined by irreversible HLA class I antigen alterations.

    Aptsiauri, Natalia; Carretero, Rafael; Garcia-Lora, Angel; Real, Luis M; Cabrera, Teresa; Garrido, Federico


    Despite the significant efforts to enhance immune reactivity against malignancies the clinical effect of anti-tumor vaccines and cancer immunotherapy is still below expectations. Understanding of the possible causes of such poor clinical outcome has become very important for improvement of the existing cancer treatment modalities. In particular, the critical role of HLA class I antigens in the success of T cell based immunotherapy has led to a growing interest in investigating the expression and function of these molecules in metastatic cancer progression and, especially in response to immunotherapy. In this report, we illustrate that two types of metastatic lesions are commonly generated in response to immunotherapy according to the pattern of HLA class I expression. We found that metastatic lesions, that progress after immunotherapy have low level of HLA class I antigens, while the regressing lesions demonstrate significant upregulation of these molecules. Presumably, immunotherapy changes tumor microenvironment and creates an additional immune selection pressure on tumor cells. As a result, two subtypes of metastatic lesions arise from pre-existing malignant cells: (a) regressors, with upregulated HLA class I expression after therapy, and (b) progressors with resistance to immunotherapy and with low level of HLA class I. Tumor cells with reversible defects (soft lesions) respond to therapy by upregulation of HLA class I expression and regress, while tumor cells with structural irreversible defects (hard lesions) demonstrate resistance to immunostimulation, fail to upregulate HLA class I antigens and eventually progress. These two types of metastases appear independently of type of the immunotherapy used, either non-specific immunomodulators (cytokines or BCG) or autologous tumor vaccination. Similarly, we also detected two types of metastatic colonies in a mouse fibrosarcoma model after in vitro treatment with IFN-gamma. One type of metastases characterized by

  3. Biochemical identification of the bovine blood group M' antigen as a major histocompatibility complex class I-like molecule

    Hønberg, L S; Larsen, B; Koch, C;


    Absorption and elution experiments showed that it was impossible to separate antibodies against blood group factor M' from antibodies against bovine lymphocyte antigen (BoLA) A16 in an antiserum showing haemolytic activity against M' as well as lymphocytotoxic activity against BoLA-A16....... To elucidate the structural relationship between BoLA-A16 and blood group antigen M', immunoprecipitation experiments on red and white cell lysates isolated from M'-A16 positive and negative cattle were carried out. These results showed that M(r) 44,000 and M(r) 12000 polypeptides can be precipitated from both...... difference in the pI of the immunoprecipitable components of red and white cells was observed. All together, this indicates that either the blood group antigen M' is the BoLA-A16 class I antigen or M' and BoLA-A16 are two different class I polypeptides with the same relative mass, sharing identical epitopes...

  4. Complement component C1r mediated cleavage of the heavy chain of the major histocompatibility class I antigens

    Eriksson, H; Nissen, Mogens Holst


    Apart from cleaving C1s, we demonstrate for the first time that: 1) at concentrations found in serum, the activated forms of the complement components C1r in addition to C1s can cleave the heavy chain of MHC class I antigens, 2) the cleavage by C1r and C1s is seemingly dependent upon a native con...... MHC class I was shown to take place between the alpha 2- and alpha 3- domains as estimated by the Con A-Sepharose precipitation pattern on SDS-PAGE. The alpha 1/alpha 2 fragment was still shown to interact with beta 2-microglobulin as shown by immunoprecipitation....

  5. Migratory dendritic cells transfer antigen to a lymph node-resident dendritic cell population for efficient CTL priming.

    Allan, Rhys S; Waithman, Jason; Bedoui, Sammy; Jones, Claerwen M; Villadangos, Jose A; Zhan, Yifan; Lew, Andrew M; Shortman, Ken; Heath, William R; Carbone, Francis R


    Skin dendritic cells (DCs) are thought to act as key initiators of local T cell immunity. Here we show that after skin infection with herpes simplex virus (HSV), cytotoxic T lymphocyte (CTL) activation required MHC class I-restricted presentation by nonmigratory CD8(+) DCs rather than skin-derived DCs. Despite a lack of direct presentation by migratory DCs, blocking their egress from infected skin substantially inhibited class I-restricted presentation and HSV-specific CTL responses. These results support the argument for initial transport of antigen by migrating DCs, followed by its transfer to the lymphoid-resident DCs for presentation and CTL priming. Given that relatively robust CTL responses were seen with small numbers of skin-emigrant DCs, we propose that this inter-DC antigen transfer functions to amplify presentation across a larger network of lymphoid-resident DCs for efficient T cell activation. PMID:16860764

  6. Proteolysis of the heavy chain of major histocompatibility complex class I antigens by complement component C1s

    Eriksson, H; Nissen, Mogens Holst


    into at least two fragments, with apparent molecular weights of 22,000 and 24,000 g/mol on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), under both reducing and non-reducing conditions. The cleavage of the heavy chain is inhibited by the presence of C1 esterase inhibitor. The......The major histocompatibility complex (MHC) class I antigens contain a light chain, beta 2-microglobulin, non-covalently associated to the transmembrane heavy alpha-chain carrying the allotypic determinants. Since the C1q complement component is known to associate with beta 2-microglobulin, and we...... mouse MHC class II antigen (I-Ad). Mouse MHC class I antigen-specific determinants could also be detected in supernatant from mouse spleen cells incubated with C1r and C1s. These results indicate the presence in the body fluids of a non-membrane-bound soluble form of the alpha 1-and alpha 2-domains...

  7. Expression of class 5 antigens by meningococcal strains obtained from patients in Brazil and evaluation of two new monoclonal antibodies

    Elizabeth N. De Gaspari


    Full Text Available Determining the profile of antigen expression among meningococci is important for epidemiologic surveillance and vaccine development. To this end, two new mouse monoclonal antibodies (MAbs have been derived against Neisseria meningitidis proteins (class 5. The MAbs were reactive against outer membrane antigens and were bactericidal. Selected anti-class 5 MAbs [(5.1-3E6-2; (5.3-3BH4-C7; (5.4-1BG11-C7; (5.5-3DH-F5G9 also 5F1F4-T3(5.c], and the two new monoclonal antibodies C14F10Br2 (5.8 and 7F11B5Br3 (5.9, were then tested against different meningococcal strains, (63 strains of serogroup A, 60 strains of serogroup C (from 1972 to 1974; and 136 strains of serogroup B (from 1992 meningococci. Our results demonstrated that the expression of class 5 proteins in the N. meningitidis B Brazilian strains studied is highly heterogeneous. The serotypes and subtypes of B:4:P1.15, B:4:P1.9, B:4:P1.7, B:4:P1.3, B:4:P1.14, B:4:P1.16, B:4:NT, and B:NT:NT were detected in N. meningitidis B serogroups.The strains C:2a:P1.2 and A:4.21:P1.9 were dominant in the C and A serogroups, respectively. Serogroup B organisms expressed the class 5 epitopes 5.4 (18%, 5.5 (22%, 5.8 (3.6%, 5.9 (8.0% and 5c (38%. Serogroup C expressed class 5 epitopes 5.1 (81%, 5.4 (35%, 5.5 (33% and 5.9 (5.0%; and serogroup A showed reactivity directed at the class 5 protein 5c (47%; and reactivity was present with the new monoclonal antibody, 5.9 (5.5%. We conclude that the two new MAbs are useful in detecting important group B, class 5 antigens, and that a broad selection of serogroup B, class 5 proteins would be required for an effective vaccine based on the class 5 proteins.

  8. Global analysis of a class of HIV models with immune response and antigenic variation

    Souza, Max O


    We study the global stability of two models for the HIV virus dynamics, that take into account the CTL immune response and antigenic variation. We show that both models are globally asymptotically stable, by using appropriate Lyapunov functions. For both models, we characterise the stable equilibrium points for the entire biologically relevant parameter range. In the model with antigenic variation, which can have a large number of equilibrium points, this allows us to determine what is the diversity of the persistent strains.

  9. T cell activation. II. Activation of human T lymphoma cells by cross-linking of their MHC class I antigens

    Dissing, S; Geisler, C; Rubin, B; Plesner, T; Claesson, M H


    The present work demonstrates that antibody-induced cross-linking of MHC class I antigens on Jurkat T lymphoma cells leads to a rise in intracellular calcium (Cai2+) and, in the presence of phorbol ester (PMA), to IL-2 production and IL-2 receptor expression. The rise in Cai2+ exhibited a profile...... very different from that obtained after anti-CD3 antibody-induced activation suggesting that activation signals are transduced differently after binding of anti-CD3 antibody and class I cross-linking, respectively. However, when Cai2+ was examined in individual Jurkat cells by means of a digital image...... the T cell receptor complex and MHC class I molecules....

  10. Simultaneous identification of Trypanosoma cruzi surface and internal antigens reactive to different immunoglobulin classes (radio-immunoblotting)

    A radioactive Western blotting technique was developed by which the reactivity of Immunoglobulins (IGs) from different classes to both membrane radiolabelled and internal parasite antigens is simultaneously identified. The method includes radioiodination of parasites, polypeptide fractionation by SDS-PAGE, Western-blot transfer and autoradiography of the immunoblots developed with anti-Igs conjugates labelled with enzymes. The analysis is then performed by the comparison of common bands on the autoradiograms and the respective substrate stained nitrocellulose blots. This technique was used to analyse. T.cruzi trypomastigote surface labelled antigens reactive to IgM, IgA and IgC specific antibodies. A different pattern of reactivity with acute Chagas disease patients sera was thus obtained. (author)

  11. Intracellular transport of MHC class II and associated invariant chain in antigen presenting cells from AP-3-deficient mocha mice.

    Sevilla, L M; Richter, S S; Miller, J


    MHC class II-restricted antigen presentation requires trafficking of newly synthesized class II-invariant chain complexes from the trans-Golgi network to endosomal, peptide-loading compartments. This transport is mediated by dileucine-like motifs within the cytosolic tail of the invariant chain. Although these signals have been well characterized, the cytosolic proteins that interact with these dileucine signals and mediate Golgi sorting and endosomal transport have not been identified. Recently, an adaptor complex, AP-3, has been identified that interacts with dileucine motifs and mediates endosomal/lysosomal transport in yeast, Drosophila, and mammals. In this report, we have assessed class II-invariant chain trafficking in a strain of mice (mocha) which lacks expression of AP-3. Our studies demonstrate that the lack of AP-3 does not affect the kinetics of invariant chain degradation, the route of class II-invariant chain transport, or the rate and extent of class II-peptide binding as assessed by the generation of SDS-stable dimers. The possible role of other known or unknown adaptor complexes in class II-invariant chain transport is discussed. PMID:11520080

  12. Hepatitis B virus-like particles access major histocompatibility class I and II antigen presentation pathways in primary dendritic cells.

    Moffat, Jessica M; Cheong, Wan-Shoo; Villadangos, José A; Mintern, Justine D; Netter, Hans J


    Virus-like particles (VLPs) represent high density displays of viral proteins that efficiently trigger immunity. VLPs composed of the small hepatitis B virus envelope protein (HBsAgS) are useful vaccine platforms that induce humoral and cellular immune responses. Notably, however, some studies suggest HBsAgS VLPs impair dendritic cell (DC) function. Here we investigated HBsAgS VLP interaction with DC subsets and antigen access to major histocompatibility complex (MHC) class I and II antigen presentation pathways in primary DCs. HBsAgS VLPs impaired plasmacytoid DC (pDC) interferon alpha (IFNα) production in response to CpG in vitro, but did not alter conventional DC (cDC) or pDC phenotype when administered in vivo. To assess cellular immune responses, HBsAgS VLPs were generated containing the ovalbumin (OVA) model epitopes OVA(257-264) and OVA(323-339) to access MHCI and MHCII antigen presentation pathways, respectively; both in vitro and following immunisation in vivo. HBsAgS VLP-OVA(257-264) elicited CTL responses in vivo that were not enhanced by inclusion of an additional MHCII helper epitope. HBsAgS VLP-OVA(257-264) administered in vivo was cross-presented by CD8(+) DCs, but not CD8(-) DCs. Therefore, HBsAgS VLPs can deliver antigen to both MHCI and MHCII antigen presentation pathways in primary DCs and promote cytotoxic and helper T cell priming despite their suppressive effect on pDCs. PMID:23473776

  13. Identification of a sulfate-bearing molecule associated with HLA class II antigens.

    Sant, A J; Cullen, S E; Schwartz, B D


    The human Ia antigens (DR, DS, and SB), determined by genes contained within the HLA complex on chromosome 6, are glycoprotein heterodimers consisting of a Mr approximately equal to 34,000 alpha chain and a Mr approximately equal to 28,000 beta chain. As a result of studies exploring the possibility that alpha or beta (or both) might be sulfated, a unique component of the oligomeric Ia antigen complex was discovered. When anti-Ia immunoprecipitates from Nonidet P-40 lysates of [35S]sulfate-la...

  14. Structural requirements for the interaction between class II MHC molecules and peptide antigens

    Sette, A; Buus, S; Appella, E; Adorini, L; Grey, H M


    Previous work from our and other laboratories indicates that T cells recognize a complex between the MHC restriction element and peptide antigen fragments. This paper reviews the structural characteristics of the formation of such a complex. By analyzing in detail the interactions between purified...

  15. Antigens of Trypanosoma cruzi detected by different classes and subclasses of antibodies.

    Araujo, F G; Heilman, B; Tighe, L


    The kinetics of the appearance of specific IgM and of subclasses of IgG antibodies following infection of mice with Trypanosoma cruzi and the antigens of amastigotes and epimastigotes recognized by these antibodies were investigated by using the indirect immunofluorescent antibody test and the protein transfer technique. IgM and IgG2 antibodies were detected almost at the same time and peaked on day 30 and 40 of infection respectively. On day 150 of infection IgM antibodies were barely detectable whereas IgG2 antibodies were still at a high titre. IgG3 and IgG1 antibodies were first detected on days 20 and 30, peaked on days 30 and 50 respectively, and were still detected at low titres on day 150 of infection. The immunofluorescent test with each antibody revealed differences in the patterns of the fluorescent staining of the organisms, particularly with amastigotes. These differences were most striking with IgG3 antibodies. Fluorescent staining with IgM or IgG1 was localized mostly on one or two poles of the amastigotes; with IgG2 it was over the entire body of either amastigotes or epimastigotes; and with IgG3 it was in the form of very small spots over the entire body of organisms of both stages. The Western blots revealed that each antibody apparently recognized the same antigens in both the epimastigote and amastigote antigen preparations. The 90 Kd MW antigen of epimastigotes as well as two antigens of MW 92 Kd and 90 Kd of amastigotes were recognized by each of the antibodies examined. PMID:6438837

  16. Defining the HLA class I-associated viral antigen repertoire from HIV-1-infected human cells

    Ternette, Nicola; Yang, Hongbing; Partridge, Thomas;


    Recognition and eradication of infected cells by cytotoxic T lymphocytes is a key defense mechanism against intracellular pathogens. High-throughput definition of HLA class I-associated immunopeptidomes by mass spectrometry is an increasingly important analytical tool to advance our understanding...... time the identification of 75 HIV-1-derived peptides bound to HLA class I complexes that were purified directly from HIV-1-infected human primary CD4+ T cells and the C8166 human T-cell line. Importantly, one-third of eluted HIV-1 peptides had not been previously known to be presented by HLA class I...

  17. Calreticulin promotes folding of functional human leukocyte antigen class I molecules in vitro.

    Culina, Slobodan; Lauvau, Grégoire; Gubler, Brigitte; van Endert, Peter M


    The assembly of MHC class I molecules with beta(2)-microglobulin and peptides is assisted by the housekeeping chaperones calnexin, calreticulin, and Erp57 and the dedicated accessory protein, tapasin. Tapasin and calreticulin are essential for efficient MHC class I assembly, but their precise action during class I assembly remains to be elucidated. Previous in vitro studies have demonstrated that the lectin calreticulin interacts with monoglucosylated MHC class I heavy chains, whatever their state of assembly with light chains and peptide, and inhibits their aggregation above physiological temperature. We used a soluble single chain HLA-A2/beta(2)-microglobulin molecule, A2SC, to study the effect of calreticulin on the peptide binding capacity of HLA class I molecules. Calreticulin inhibited the formation of A2SC aggregates both when co-expressed in insect cells and during incubations at elevated temperature. Calreticulin dramatically enhanced acquisition of peptide binding capacity when added to denatured A2SC molecules during refolding at 4 degrees C. However, it had no effect on the rapid loss of A2SC peptide binding capacity at physiological temperature. We conclude that calreticulin promotes the folding of HLA class I molecules to a state in which, at low temperature, they spontaneously acquire peptide binding capacity. However, it does not induce or maintain a peptide-receptive state of the class I-binding site, which is likely to be promoted by one or several other components of the class I loading complexes. By being amenable to complementation with additional proteins, the described system should be useful for identification of these components. PMID:15494401

  18. Characterization of antigen processing and presentation by peptide-linked MHC class I molecules

    Tiwari, Neeraj


    MHC-Klasse-I-Moleküle präsentieren gewöhnlich Peptide, die aus zytosolischen Antigenproteinen durch proteasomalen Verdau generiert und anschließend vom TAP-Peptidtransporter ins endoplasmatische Retikulum transportiert werden. Es können jedoch auch endozytierte Antigene für die MHC-Klasse-I-vermittelten Antigenpräsentation prozessiert werden, wobei dieser alternative Weg entweder in einer Proteasom/TAP-abhängigen oder unabhängigen Weise abläuft. Während diese so genannte „Kreuzpräsentation“ f...

  19. Inhibition of Class II Major Histocompatibility Complex Antigen Processing by Escherichia coli Heat-Labile Enterotoxin Requires an Enzymatically Active A Subunit

    Matousek, Milita P.; Nedrud, John G.; Cieplak, Witold; Harding, Clifford V.


    Escherichia coli heat-labile enterotoxin (LT) and cholera toxin (CT) were found to inhibit intracellular antigen processing. Processing was not inhibited by mutant LT with attenuated ADP-ribosyltransferase activity, CT B or LT B subunit, which enhanced presentation of preexisting cell surface peptide-class II major histocompatibility complex complexes. Inhibition of antigen processing correlated with A subunit ADP-ribosyltransferase activity. PMID:9632629

  20. Cross-Reaction between the Crude Hydatid Cyst Fluid Antigens of Human and Animals Origin in Response to Human IgG Class and Subclasses

    Afra Khosravi; Sobhan Ghafourian; Morteza Shamsi; Nourkhoda Sadeghifard; Abbas Maleki; Ebrahim Babaahmadi


    The current work aimed to evaluate the cross-reactivity of human immune sera against crude hydatid fluid antigens of sheep, human, mouse, cattle, as well as B fraction of cystic fluid antigen. 30 balb/c mice were infected with sheep hydatid cyct fluid antigen containing protoscolex after the viability of these protoscolices was assessed. ANOVA was used to test the difference of themean of optical density (OD) values among case and control groups. The highest human IgG class antibody was again...

  1. Structure and expression of genes encoding murine Qa-2 class I antigens.

    Mellor, A L; Antoniou, J; Robinson, P J


    DNA structural analysis of the Qa region in two BALB/c mouse substrains with different Qa-2 phenotypes reveals that a deletion of DNA has occurred in BALB/cBy (Qa-2-) mice relative to BALB/c (Qa-2+) mice. We propose that this deletion arises from unequal crossing-over and recombination between adjacent BALB/c class I genes and results in the generation of a hybrid class I gene in BALB/cBy mice. Furthermore, we suggest that this is a direct cause of the change in Qa-2 phenotype. Further suppor...

  2. Anionic Sites, Fucose Residues and Class I Human Leukocyte Antigen Fate During Interaction of Toxoplasma gondii with Endothelial Cells

    Stumbo Ana Carolina


    Full Text Available Toxoplasma gondii invades and proliferates in human umbilical vein endothelial cells where it resides in a parasitophorous vacuole. In order to analyze which components of the endothelial cell plasma membrane are internalized and become part of the parasitophorous vacuole membrane, the culture of endothelial cells was labeled with cationized ferritin or UEA I lectin or anti Class I human leukocytte antigen (HLA before or after infection with T. gondii. The results showed no cationized ferritin and UEA I lectin in any parasitophorous vacuole membrane, however, the Class I HLA molecule labeling was observed in some endocytic vacuoles containing parasite until 1 h of interaction with T. gondii. After 24 h parasite-host cell interaction, the labeling was absent on the vacuolar membrane, but presents only in small vesicles near parasitophorous vacuole. These results suggest the anionic site and fucose residues are excluded at the time of parasitophorous vacuole formation while Class I HLA molecules are present only on a minority of Toxoplasma-containig vacuoles.

  3. Major histocompatibility complex class II (DR) antigen and costimulatory molecules on in vitro and in vivo activated human polymorphonuclear neutrophils

    Sandilands, Gavin P; McCrae, Jame; Hill, Kathryn; Perry, Martin; Baxter, Derek


    We have previously shown that normal human peripheral blood polymorphonuclear neutrophils (PMNs) contain cytoplasmic ‘stores’ of three key molecules normally associated with antigen presentation and T-cell costimulation, i.e. major histocompatibility complex class II (DR) antigen, CD80 (B7-1) and CD86 (B7-2). These cytoplasmic molecules were found to translocate to the cell surface within a few minutes following cross-linking (X-L) of Mac-1: an early neutrophil activation signal. In this study we have compared X-L of Mac −1 in parallel with four other well documented in vitro neutrophil activators: phorbol myristate acetate, N-formyl methionyl leucyl phenylalanine, lipopolysaccharide, and phagocytosis of immunoglobulin G–Latex particles. In addition, we have used paired samples of neutrophils obtained from peripheral blood (as a control) and synovial fluid from patients with rheumatoid arthritis as a source of in vivo activated cells. With the exception of phagocytosis, all activators resulted in the rapid (within 30 min) generation of two populations of activated neutrophils (designated P1 and P2) based on flow-cytometry measurements of size, granularity and phenotype. Significant up-regulation of DR and costimulatory molecules was observed, predominantly on P2 cells, with all activators except phagocytosis. CD80 and CD86 were noted to respond to the various activation signals in a different pattern suggesting that their intracellular granule location may be different. Dual-staining confocal laser microscopy studies showed that CD80 is largely confined to secretory vesicles (SVs) while CD86 appears to have a much wider distribution being found in SVs and within secondary (specific) and primary (azurophilic) granules. Increased surface expression of these antigens was also observed on P2 synovial fluid neutrophils appearing as large heterogeneous clusters on the cell surface when visualized by confocal laser microscopy. PMID:17034427

  4. Antibodies against a class II HLA-peptide complex raised by active immunization of mice with antigen mimicking peptides

    Dam-Tuxen, R; Riise, Erik Skjold


    Multiple sclerosis (MS) is an autoimmune disease linked to the human leucocyte antigen (HLA) class II genes DRB1*1501, DRB5*0101 and DQB1*0602. T cells reactive towards the DRB1*1501 in complex with various peptides derived from myelin basic protein (MBP), which is the major component of myelin......, have been found in the peripheral blood of MS patients. These autoreactive T cells are believed to play a role in the pathogenesis of MS. In this article, antibodies against the HLA complex DR2b (DRA1*0101/DRB1*1501) in complex with the MBP-derived peptide MBP(85-99) have been generated by immunization...

  5. Characterization of the Antigen Processing Machinery and Endogenous Peptide Presentation of a Bat MHC Class I Molecule.

    Wynne, James W; Woon, Amanda P; Dudek, Nadine L; Croft, Nathan P; Ng, Justin H J; Baker, Michelle L; Wang, Lin-Fa; Purcell, Anthony W


    Bats are a major reservoir of emerging and re-emerging infectious diseases, including severe acute respiratory syndrome-like coronaviruses, henipaviruses, and Ebola virus. Although highly pathogenic to their spillover hosts, bats harbor these viruses, and a large number of other viruses, with little or no clinical signs of disease. How bats asymptomatically coexist with these viruses is unknown. In particular, little is known about bat adaptive immunity, and the presence of functional MHC molecules is mostly inferred from recently described genomes. In this study, we used an affinity purification/mass spectrometry approach to demonstrate that a bat MHC class I molecule, Ptal-N*01:01, binds antigenic peptides and associates with peptide-loading complex components. We identified several bat MHC class I-binding partners, including calnexin, calreticulin, protein disulfide isomerase A3, tapasin, TAP1, and TAP2. Additionally, endogenous peptide ligands isolated from Ptal-N*01:01 displayed a relatively broad length distribution and an unusual preference for a C-terminal proline residue. Finally, we demonstrate that this preference for C-terminal proline residues was observed in Hendra virus-derived peptides presented by Ptal-N*01:01 on the surface of infected cells. To our knowledge, this is the first study to identify endogenous and viral MHC class I ligands for any bat species and, as such, provides an important avenue for monitoring and development of vaccines against major bat-borne viruses both in the reservoir and spillover hosts. Additionally, it will provide a foundation to understand the role of adaptive immunity in bat antiviral responses. PMID:27183594

  6. Survival of ovarian cancer patients overexpressing the tumour antigen p53 is diminished in case of MHC class I down-regulation

    Leffers, Ninke; Lambeck, Annechien J. A.; de Graeff, Pauline; Bijlsma, Astrid Y.; Daemen, Toos; van der Zee, Ate G. J.; Nijman, Hans W.


    Objectives. The adaptive immune system seems to play an essential role in the natural course of ovarian cancer. Aim of this study was to establish whether disease-specific survival for patients expressing the tumour antigen p53 is influenced by MHC class I expression or the presence of p53 autoantib

  7. Human leukocyte antigen class II DQB1*0301, DRB1*1101 alleles and spontaneous clearance of hepatitis C virus infection: A meta-analysis

    Hong, Xin; Yu, Rong-Bin; Sun, Nan-Xiong; Wang, Bin; Xu, Yao-Chu; Wu, Guan-Ling


    AIM: To assess the associations of human leukocyte antigen (HLA) class II DQB1*0301 and/or DRB1*1101 allele with spontaneous hepatitis C virus (HCV) clearance by meta-analysis of individual dataset from all studies published till date.

  8. HLA Class II Antigens and Their Interactive Effect on Perinatal Mother-To-Child HIV-1 Transmission.

    Ma Luo

    Full Text Available HLA class II antigens are central in initiating antigen-specific CD4+ T cell responses to HIV-1. Specific alleles have been associated with differential responses to HIV-1 infection and disease among adults. This study aims to determine the influence of HLA class II genes and their interactive effect on mother-child perinatal transmission in a drug naïve, Mother-Child HIV transmission cohort established in Kenya, Africa in 1986. Our study showed that DRB concordance between mother and child increased risk of perinatal HIV transmission by three fold (P = 0.00035/Pc = 0.0014, OR: 3.09, 95%CI, 1.64-5.83. Whereas, DPA1, DPB1 and DQB1 concordance between mother and child had no significant influence on perinatal HIV transmission. In addition, stratified analysis showed that DRB1*15:03+ phenotype (mother or child significantly increases the risk of perinatal HIV-1 transmission. Without DRB1*15:03, DRB1 discordance between mother and child provided 5 fold protection (P = 0.00008, OR: 0.186, 95%CI: 0.081-0.427. However, the protective effect of DRB discordance was diminished if either the mother or the child was DRB1*15:03+ phenotype (P = 0.49-0.98, OR: 0.7-0.99, 95%CI: 0.246-2.956. DRB3+ children were less likely to be infected perinatally (P = 0.0006, Pc = 0.014; OR:0.343, 95%CI:0.183-0.642. However, there is a 4 fold increase in risk of being infected at birth if DRB3+ children were born to DRB1*15:03+ mother compared to those with DRB1*15:03- mother. Our study showed that DRB concordance/discordance, DRB1*15:03, children's DRB3 phenotype and their interactions play an important role in perinatal HIV transmission. Identification of genetic factors associated with protection or increased risk in perinatal transmission will help develop alternative prevention and treatment methods in the event of increases in drug resistance of ARV.

  9. Down-regulation of Human Leukocyte Antigen class I heavy chain in tumors is associated with a poor prognosis in advanced esophageal cancer patients

    Tanaka, Kimitaka; Tsuchikawa, Takahiro; Miyamoto, Masaki; Maki, Takehiro; ICHINOKAWA, MASAOMI; KUBOTA, KANAKO C.; Shichinohe, Toshiaki; Hirano, Satoshi; Ferrone, Soldano; DOSAKA-AKITA, HIROTOSHI; Matsuno, Yoshihiro; Kondo, Satoshi


    The HLA class I antigen processing machinery (APM) plays a crucial role in the anticancer immune response. The aim of this study was to assess the clinical significance of APM components in esophageal cancer. A total of 11 esophageal cancer cell lines were evaluated by Western blot analysis for 13 HLA class I APM components. There was a different expression pattern among cancer cell lines for HLA class I heavy chain (HLA-HC), β2 microglobulin, Tapasin, TAP-1, TAP-2, LMP-7 and LMP-10. Immunohi...

  10. Down-regulation of Human Leukocyte Antigen class I heavy chain in tumors is associated with a poor prognosis in advanced esophageal cancer patients

    Tanaka, Kimitaka; Tsuchikawa, Takahiro; Miyamoto, Masaki; Maki, Takehiro; ICHINOKAWA, MASAOMI; KUBOTA, KANAKO C.; Shichinohe, Toshiaki; Hirano, Satoshi; Ferrone, Soldano; DOSAKA-AKITA, HIROTOSHI; Matsuno, Yoshihiro; Kondo, Satoshi


    The HLA class I antigen processing machinery (APM) plays a crucial role in the anticancer immune response. The aim of this study was to assess the clinical significance of APM components in esophageal cancer. A total of 11 esophageal cancer cell lines were evaluated by Western blot analysis for 13 HLA class I APM components. There was a different expression pattern among cancer cell lines for HLA class I heavy chain (HLA-HC), β2 microglobulin, Tapasin, TAP-1, TAP-2, LMP-7 and LMP-10. Immunohi...

  11. Tumor associated antigen specific T-cell populations identified in ex vivo expanded TIL cultures

    Junker, Niels; Kvistborg, Pia; Køllgaard, Tania;


    Ex vivo expanded tumor infiltrating lymphocytes (TILs) from malignant melanoma (MM) and head & neck squamous cell carcinoma (HNSCC) share a similar oligoclonal composition of T effector memory cells, with HLA class I restricted lysis of tumor cell lines. In this study we show that ex vivo expanded...... TILs from MM and HNSCC demonstrate a heterogeneous composition in frequency and magnitude of tumor associated antigen specific populations by Elispot IFN¿ quantitation. TILs from MM and HNSCC shared reactivity towards NY ESO-1, cyclin B1 and Bcl-x derived peptides. Additionally we show that dominating...

  12. Enhanced T cell responses to antigenic peptides targeted to B cell surface Ig, Ia, or class I molecules


    The helper T cell recognition of soluble globular protein antigens requires that the proteins be processed by an APC, releasing a peptide that is transported to and held on the APC surface where it is recognized by the specific T cell in conjunction with Ia. When cellular processing functions are blocked, APC lose their ability to present native antigens while retaining the capacity to activate T cells when provided with a cognate peptide fragment that contains the T cell antigenic determinan...

  13. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection

    Leroux, Louis-Philippe; Nishi, Manami; El-Hage, Sandy; Fox, Barbara A.; Bzik, David J.; Dzierszinski, Florence S.


    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4+ T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms...

  14. Diversity of natural self-derived ligands presented by different HLA class I molecules in transporter antigen processing-deficient cells.

    Elena Lorente

    Full Text Available The transporter associated with antigen processing (TAP translocates the cytosol-derived proteolytic peptides to the endoplasmic reticulum lumen where they complex with nascent human leukocyte antigen (HLA class I molecules. Non-functional TAP complexes and viral or tumoral blocking of these transporters leads to reduced HLA class I surface expression and a drastic change in the available peptide repertoire. Using mass spectrometry to analyze complex human leukocyte antigen HLA-bound peptide pools isolated from large numbers of TAP-deficient cells, we identified 334 TAP-independent ligands naturally presented by four different HLA-A, -B, and -C class I molecules with very different TAP dependency from the same cell line. The repertoire of TAP-independent peptides examined favored increased peptide lengths and a lack of strict binding motifs for all four HLA class I molecules studied. The TAP-independent peptidome arose from 182 parental proteins, the majority of which yielded one HLA ligand. In contrast, TAP-independent antigen processing of very few cellular proteins generated multiple HLA ligands. Comparison between TAP-independent peptidome and proteome of several subcellular locations suggests that the secretory vesicle-like organelles could be a relevant source of parental proteins for TAP-independent HLA ligands. Finally, a predominant endoproteolytic peptidase specificity for Arg/Lys or Leu/Phe residues in the P(1 position of the scissile bond was found for the TAP-independent ligands. These data draw a new and intricate picture of TAP-independent pathways.

  15. Human leukocyte antigen class I and II alleles and cervical adenocarcinoma: a pooled analysis of two epidemiologic studies

    Mahboobeh eSafaeian


    Full Text Available Associations between human leukocyte antigens (HLA alleles and cervical cancer are largely representative of squamous cell carcinoma (SCC, the major histologic subtype. We evaluated the association between HLA class I (A, B, and C and class II (DRB1 and DQB1 loci and risk of cervical adenocarcinoma (ADC, a less common but aggressive histologic subtype.We pooled data from the Eastern and Western US cervical cancer studies, and evaluated the association between individual alleles and allele combinations and ADC (n=630 ADC; n=775 controls. Risk estimates were calculated for 11 a priori (based on known associations with cervical cancer regardless of histologic type and 38 non a priori common alleles, as odds ratios (OR and 95% confidence intervals (CI, adjusted for age and study. In exploratory analysis, we compared the risk associations between subgroups with HPV16 or HPV18 DNA in ADC tumor tissues in the Western US study cases and controls. Three of the a priori alleles were significantly associated with decreased risk of ADC (DRB1*13:01 (OR=0.61; 95%CI:0.41-0.93, DRB1*13:02 (OR=0.49; 95%CI:0.31-0.77, and DQB1*06:03 (OR=0.64; 95%CI:0.42-0.95; one was associated with increased risk (B*07:02(OR=1.39; 95%CI:1.07-1.79. Among alleles not previously reported, DQB1*06:04 (OR=0.46; 95%CI: 0.27-0.78 was associated with decreased risk of ADC and C*07:02 (OR=1.41; 95%CI:1.09-1.81 was associated with increased risk. We did not observe a difference by histologic subtype. ADC was most strongly associated with increased risk with B*07:02/C*07:02 alleles (OR=1.33; 95%CI:1.01-1.76 and decreased risk with DRB1*13:02/DQB1*06:04 (OR=0.41; 95%CI:0.21-0.80. Results suggest that HLA allele associations with cervical ADC are similar to those for cervical SCC. An intriguing finding was the difference in risk associated with several alleles restricted to HPV16 or HPV18 related tumors, consistent with the hypothesis that HLA recognition is HPV type specific.

  16. Human Leukocyte Antigen Class I and II Alleles and Overall Survival in Diffuse Large B-Cell Lymphoma and Follicular Lymphoma

    Yani Lu; Amr M Abdou; Cerhan, James R.; Morton, Lindsay M.; Richard K Severson; Scott Davis; Wendy Cozen; Nathaniel Rothman; Leslie Bernstein; Stephen Chanock; Patricia Hartge; Wang, Sophia S.


    Genetic variation in the 6p21 chromosomal region, including human leukocyte antigen (HLA) genes and tumor necrosis factor (TNF), has been linked to both etiology and clinical outcomes of lymphomas. We estimated the effects of HLA class I (A, B, and C), class II DRB1 alleles, and the ancestral haplotype (AH) 8.1 (HLAA*01-B*08-DRB1*03-TNF-308A) on overall survival (OS) among patients with diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) in a population-based study of non-Hodgk...

  17. High resolution human leukocyte antigen (HLA class I and class II allele typing in Mexican mestizo women with sporadic breast cancer: case-control study

    Barquera Rodrigo


    Full Text Available Abstract Background The development of breast cancer is multifactorial. Hormonal, environmental factors and genetic predisposition, among others, could interact in the presentation of breast carcinoma. Human leukocyte antigen (HLA alleles play an important role in immunity (cellular immunity and may be important genetic traits. HLAAllele-specific interaction has not been well established. Recently, several studies had been conducted in order to do so, but the results are controversial and in some instances contradictory. Methods We designed a case-control study to quantify the association of HLA class I and II genes and breast cancer. HLA typing was performed by high resolution sequence-specific oligotyping after DNA amplification (PCR-SSOP of 100 breast cancer Mexican mestizo patients and 99 matched healthy controls. Results HLA-A frequencies that we were able to observe that there was no difference between both groups from the statistical viewpoint. HLA-B*1501 was found three times more common in the case group (OR, 3.714; p = 0.031. HLA-Cw is not a marker neither for risk, nor protection for the disease, because we did not find significant statistical differences between the two groups. DRB1*1301, which is expressed in seven cases and in only one control, observing an risk increase of up to seven times and DRB1*1602, which behaves similarly in being present solely in the cases (OR, 16.701; 95% CI, 0.947 – 294.670. DQ*0301-allele expression, which is much more common in the control group and could be protective for the presentation of the disease (OR, 0.078; 95% CI, 0.027–0.223, p = 0.00001. Conclusion Our results reveal the role of the MHC genes in the pathophysiology of breast cancer, suggesting that in the development of breast cancer exists a disorder of immune regulation. The triggering factor seems to be restricted to certain ethnic groups and certain geographical regions since the relevant MHC alleles are highly diverse. This is the

  18. High resolution human leukocyte antigen (HLA) class I and class II allele typing in Mexican mestizo women with sporadic breast cancer: case-control study

    The development of breast cancer is multifactorial. Hormonal, environmental factors and genetic predisposition, among others, could interact in the presentation of breast carcinoma. Human leukocyte antigen (HLA) alleles play an important role in immunity (cellular immunity) and may be important genetic traits. HLAAllele-specific interaction has not been well established. Recently, several studies had been conducted in order to do so, but the results are controversial and in some instances contradictory. We designed a case-control study to quantify the association of HLA class I and II genes and breast cancer. HLA typing was performed by high resolution sequence-specific oligotyping after DNA amplification (PCR-SSOP) of 100 breast cancer Mexican mestizo patients and 99 matched healthy controls. HLA-A frequencies that we were able to observe that there was no difference between both groups from the statistical viewpoint. HLA-B*1501 was found three times more common in the case group (OR, 3.714; p = 0.031). HLA-Cw is not a marker neither for risk, nor protection for the disease, because we did not find significant statistical differences between the two groups. DRB1*1301, which is expressed in seven cases and in only one control, observing an risk increase of up to seven times and DRB1*1602, which behaves similarly in being present solely in the cases (OR, 16.701; 95% CI, 0.947 – 294.670). DQ*0301-allele expression, which is much more common in the control group and could be protective for the presentation of the disease (OR, 0.078; 95% CI, 0.027–0.223, p = 0.00001). Our results reveal the role of the MHC genes in the pathophysiology of breast cancer, suggesting that in the development of breast cancer exists a disorder of immune regulation. The triggering factor seems to be restricted to certain ethnic groups and certain geographical regions since the relevant MHC alleles are highly diverse. This is the first study in Mexican population where high resolutions HLA

  19. Asparagine endopeptidase is not essential for class II MHC antigen presentation but is required for processing of cathepsin L in mice.

    Maehr, René; Hang, Howard C; Mintern, Justine D; Kim, You-Me; Cuvillier, Armelle; Nishimura, Mikio; Yamada, Kenji; Shirahama-Noda, Kanae; Hara-Nishimura, Ikuko; Ploegh, Hidde L


    Class II MHC molecules survey the endocytic compartments of APCs and present antigenic peptides to CD4 T cells. In this context, lysosomal proteases are essential not only for the generation of antigenic peptides but also for proteolysis of the invariant chain to allow the maturation of class II MHC molecules. Recent studies with protease inhibitors have implicated the asparagine endopeptidase (AEP) in class II MHC-restricted Ag presentation. We now report that AEP-deficient mice show no differences in processing of the invariant chain or maturation of class II MHC products compared with wild-type mice. In the absence of AEP, presentation to primary T cells of OVA and myelin oligodendrocyte glycoprotein, two Ags that contain asparagine residues within or in proximity to the relevant epitopes was unimpaired. Cathepsin (Cat) L, a lysosomal cysteine protease essential for the development to CD4 and NK T cells, fails to be processed into its mature two-chain form in AEP-deficient cells. Despite this, the numbers of CD4 and NK T cells are normal, showing that the single-chain form of Cat L is sufficient for its function in vivo. We conclude that AEP is essential for processing of Cat L but not for class II MHC-restricted Ag presentation. PMID:15905550

  20. Up-regulation of HLA class-I antigen expression and antigen-specific CTL response in cervical cancer cells by the demethylating agent hydralazine and the histone deacetylase inhibitor valproic acid

    Lizano-Soberón Marcela


    Full Text Available Abstract Background DNA hypermethylation and histone deacetylation are epigenetic events that contribute to the absence or downregulated expression of different components of the tumor recognition complex. These events affect the processing and presentation of antigenic peptides to CTLs by HLA class-I molecules. In this work evaluated the effect of the DNA hypomethylating agent hydralazine and the histone deacetylase inhibitor valproic acid, on the expression of HLA class-I molecules and on the antigen-specific immune recognition of cervical cancer cells. Methods Cell lines C33A (HPV-, CaSki (HPV-16+ and MS751 (HPV-18+ were treated with hydralazine and valproic acid to assess the expression of HLA class-I molecules by flow cytometry and RT-PCR. Promoter methylation of HLA class-I -A, -B and C, was also evaluated by Methylation-Specific PCR. Primary cervical tumors of four HLA-A*0201 allele patients were typed for HPV and their CTL's stimulated in vitro with the T2 cell line previously loaded with 50 μM of the HPV peptides. Cytotoxicity of stimulated CTL's was assayed against Caski and MS751 cells pre-treated with hydralazine and valproic acid. Results Valproic acid and hydralazine/valproic acid up-regulated the constitutive HLA class-I expression as evaluated by flow cytometry and RT-PCR despite constitutive promoter demethylation at these loci. Hydralazine and valproic acid in combination but no IFN-gamma hyperacetylated histone H4 as evaluated by ChiP assay. The antigenic immune recognition of CaSki and MS751 cells by CTLs specific to HPV-16/18 E6 and E7-derived epitopes, was increased by VA and H/VA and the combination of H/VA/IFN-gamma. Conclusion These results support the potential use of hydralazine and valproic acid as an adjuvant for immune intervention in cervical cancer patients whenever clinical protocols based on tumor antigen recognition is desirable, like in those cases where the application of E6 and E7 based therapeutic vaccines

  1. Identification of peptides fromm foot-and-mouth disease virus structural proteins bound by class I swine leucocyte antigen (SLA) alleles, SLA-1*0401 and SLA-2*0401

    The analysis of peptide binding to porcine major histocompatibility complex (MHC) class I molecules has not been extensively performed. Critical to understanding the adaptive immune response of swine to infection is characterization of Swine Leucocyte Antigens (SLA) class I and class II peptide bind...

  2. Analysis of endogenous peptides bound by soluble MHC class I molecules: a novel approach for identifying tumor-specific antigens.

    Barnea, Eilon; Beer, Ilan; Patoka, Renana; Ziv, Tamar; Kessler, Ofra; Tzehoval, Esther; Eisenbach, Lea; Zavazava, Nicholas; Admon, Arie


    The Human MHC Project aims at comprehensive cataloging of peptides presented within the context of different human leukocyte antigens (HLA) expressed by cells of various tissue origins, both in health and in disease. Of major interest are peptides presented on cancer cells, which include peptides derived from tumor antigens that are of interest for immunotherapy. Here, HLA-restricted tumor-specific antigens were identified by transfecting human breast, ovarian and prostate tumor cell lines with truncated genes of HLA-A2 and HLA-B7. Soluble HLA secreted by these cell lines were purified by affinity chromatography and analyzed by nano-capillary electrospray ionization-tandem mass spectrometry. Typically, a large peptide pool was recovered and sequenced including peptides derived from MAGE-B2 and mucin and other new tumor-derived antigens that may serve as potential candidates for immunotherapy. PMID:11782012

  3. Negative staining and immunoelectron microscopy of adhesion-deficient mutants of Streptococcus salivarius reveal that the adhesive protein antigens are separate classes of cell surface fibril.

    Weerkamp, A H; Handley, P S; Baars, A; Slot, J W


    The subcellular distribution of the cell wall-associated protein antigens of Streptococcus salivarius HB, which are involved in specific adhesive properties of the cells, was studied. Mutants which had lost the adhesive properties and lacked the antigens at the cell surface were compared with the parent strain. Immunoelectron microscopy of cryosections of cells labeled with affinity-purified, specific antisera and colloidal gold-protein A complexes was used to locate the antigens. Antigen C (AgC), a glycoprotein involved in attachment to host surfaces, was mainly located in the fibrillar layer outside the cell wall. A smaller amount of label was also found throughout the cytoplasmic area in the form of small clusters of gold particles, which suggests a macromolecular association. Mutant HB-7, which lacks the wall-associated AgC, accumulated AgC reactivity intracellularly. Intracellular AgC was often found associated with isolated areas of increased electron density, but sometimes seemed to fill the entire interior of the cell. Antigen B (AgB), a protein responsible for interbacterial coaggregation, was also located in the fibrillar layer, although its distribution differed from that of the wall-associated AgC since AgB was found predominantly in the peripheral areas. A very small amount of label was also found in the cytoplasmic area as discrete gold particles. Mutant HB-V5, which lacks wall-associated AgB, was not labeled in the fibrillar coat, but showed the same weak intracellular label as the parent strain. Immunolabeling with serum against AgD, another wall-associated protein but of unknown function, demonstrated its presence in the fibrillar layer of strain HB. Negatively stained preparations of whole cells of wild-type S. salivarius and mutants that had lost wall-associated AgB or AgC revealed that two classes of short fibrils are carried on the cell surface at the same time. AgB and AgC are probably located on separate classes of short, protease

  4. Cloning and characterization of the genes encoding the MspI restriction modification system.

    Lin, P M; Lee, C. H.; Roberts, R J


    The genes encoding the MspI restriction modification system, which recognizes the sequence 5' CCGG, have been cloned into pUC9. Selection was based on expression of the cloned methylase gene which renders plasmid DNA insensitive to MspI cleavage in vitro. Initially, an insert of 15 kb was obtained which, upon subcloning, yielded a 3 kb EcoRI to HindIII insert, carrying the genes for both the methylase and the restriction enzyme. This insert has been sequenced. Based upon the sequence, togethe...

  5. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection.

    Leroux, Louis-Philippe; Nishi, Manami; El-Hage, Sandy; Fox, Barbara A; Bzik, David J; Dzierszinski, Florence S


    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4(+) T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms inhibiting MHC-II function are currently unknown. Here, we show that, in addition to transcriptional regulation of MHC-II, the parasite modulates the expression of key components of the MHC-II antigen presentation pathway, namely, the MHC-II-associated invariant chain (Ii or CD74) and the peptide editor H2-DM, in professional antigen-presenting cells (pAPCs). Genetic deletion of CD74 restored the ability of infected dendritic cells to present a parasite antigen in the context of MHC-II in vitro. CD74 mRNA and protein levels were, surprisingly, elevated in infected cells, whereas MHC-II and H2-DM expression was inhibited. CD74 accumulated mainly in the endoplasmic reticulum (ER), and this phenotype required live parasites, but not active replication. Finally, we compared the impacts of genetic deletion of CD74 and H2-DM genes on parasite dissemination toward lymphoid organs in mice, as well as activation of CD4(+) T cells and interferon gamma (IFN-γ) levels during acute infection. Cyst burdens and survival during the chronic phase of infection were also evaluated in wild-type and knockout mice. These results highlight the fact that the infection is influenced by multiple levels of parasite manipulation of the MHC-II antigen presentation pathway. PMID:26195549

  6. Yeast retrotransposon particles as antigen delivery systems.

    Kingsman, A J; Burns, N R; Layton, G T; Adams, S E


    The development of technologies to produce recombinant proteins for use in the pharmaceutical industry has made substantial advances, in particular in the area of generating antigens containing multiple copies of important immunological regions. One such antigen-carrier system is based on the ability of a protein encoded by the yeast retrotransposon, Ty, to self-assemble into virus-like particles. Ty-fusion proteins retain this ability to form particles, and a range of hybrid VLPs carrying a variety of heterologous antigens have been produced and shown to induce potent immune responses. In particular, hybrid VLPs carrying the core protein p24 of HIV (p24-VLPs) have been shown to induce antibody and T-cell proliferative responses in both experimental animals and human volunteers, and immunization of rabbits with VLPs carrying the principal neutralizing determinant of HIV (V3-VLPs) resulted in the induction of neutralizing antibody responses and T-cell proliferation. Further studies with V3-VLPs have shown that this particulate antigen stimulates enhanced V3-specific lymphoproliferative responses as compared to whole recombinant gp120 or to V3 peptide conjugated to albumin. The V3-VLPs also induce potent CTL responses following immunization of mice in the absence of adjuvant. These responses are MHC class I restricted and are mediated by CD8-positive cells. These observations therefore demonstrate that hybrid Ty-VLPs induce both humoral and cellular immune responses against HIV and suggest that these immunogens may be important in combatting AIDS and other infections. PMID:7625653

  7. Equivalence of human and mouse CD4 in enhancing antigen responses by a mouse class II-restricted T cell hybridoma


    We have examined the ability of hCD4 to interact functionally with mouse class II MHC molecules using the mouse T cell hybridoma BI-141, specific for beef insulin. We have previously shown that expression of mouse CD4 results in a marked enhancement of IL-2 release by BI-141 cells in response to beef insulin or, in a cross-reactive response, to pork insulin, on the appropriate mouse APCs. We now demonstrate that expression of hCD4 results in an equivalent stimulation of antigen responses by t...

  8. Downregulation of CD99 and upregulation of human leukocyte antigen class II promote tumor aggravation and poor survival in patients with osteosarcomas

    Zhou Q; Xu J; Zhao J; Zhang S; Pan W


    Quan Zhou,* Jin Xu,* Jiali Zhao, Shaoxian Zhang, Wei PanDepartment of Orthopaedics, the second Hospital of Huai'an city Affiliated to Xuzhou Medical College and the second Hospital of Huai'an city, Huai'an, People's Republic of China *These authors contributed equally to this workBackground: CD99 is involved in the intracellular transport of human leukocyte antigen class II (HLA-II) protein. The aim of this study was to clarify the clinical value of CD99 and HL...

  9. Simian and Human Immunodeficiency Virus Nef Proteins Use Different Surfaces To Downregulate Class I Major Histocompatibility Complex Antigen Expression

    Swigut, Tomek; Iafrate, A. John; Muench, Jan; Kirchhoff, Frank; Skowronski, Jacek


    Simian immunodeficiency virus (SIV) and human immunodeficiency virus type 1 (HIV-1) Nef proteins are related regulatory proteins that share several functions, including the ability to downregulate class I major histocompatibility complex (MHC) and CD4 expression on the cell surface and to alter T-cell-receptor-initiated signal transduction in T cells. We compared the mechanisms used by SIV mac239 Nef and HIV-1 Nef to downregulate class I MHC and found that the ability of SIV Nef to downregula...

  10. Small organic compounds enhance antigen loading of class II major histocompatibility complex proteins by targeting the polymorphic P1 pocket

    Höpner, Sabine; Dickhaut, Katharina; Hofstätter, Maria;


    the peptide loading rate. The effect was evident only for an allelic subset and strictly correlated with the presence of glycine at the dimorphic position beta86 of the HLA-DR molecule. The residue forms the floor of the conserved pocket P1, located in the peptide binding site of MHC molecule...... "adamantyl-susceptible" MHC molecules. As catalysts of antigen loading, compounds targeting P1 may be useful molecular tools to amplify the immune response. The observation, however, that the ligand repertoire can be affected through polymorphic sites form the outside may also imply that environmental...

  11. Structural features of class I H-2 antigens revealed by anti-peptide antibodies specific for intracytoplasmic determinants

    Rabbit antisera specific for synthetic peptides corresponding to each of the three intracytoplasmic exons (i.e. exons 6, 7 and 8) of the H-2K/sup b/ gene have been prepared and characterized in terms of their reactivity with class I H-2 molecules. Using lentil lectin-purified glycoproteins isolated from 125I-surface-labelled EL-4 (H-2/sup b/) cells, it has been possible to demonstrate that after clearance of the glycoprotein preparation with either anti-mouse β2-microglobulin, or alloantisera directed against H-2K/sup b/ and D/sup b/, there remains a non-β2-microglobulin-associated (i.e. free) class I heavy chain which can be immunoprecipitated by anti-peptide 8 antisera. This free class I heavy chain has the same 2D gel spot pattern as heavy chains from dimeric H-2K/sup b/, suggesting that conformational alterations resulting from the dissociation of β2-microglobulin, rather than chemical changes, are responsible for the loss of the alloantigenic determinants. Evidence has also been obtained indicating that the reaction of dimeric class I molecules with anti-peptide 6 induces the dissociation of β2-microglobulin, suggesting the potential for significant transmembrane conformational perturbations of the external domains as a result of interactions with the intracytoplasmic region

  12. High resolution human leukocyte antigen class I allele frequencies and HIV-1 infection associations in Chinese Han and Uyghur cohorts.

    Yanhou Liu

    Full Text Available BACKGROUND: Host immunogenetic factors such as HLA class I polymorphism are important to HIV-1 infection risk and AIDS progression. Previous studies using high-resolution HLA class I profile data of Chinese populations appeared insufficient to provide information for HIV-1 vaccine development and clinical trial design. Here we reported HLA class I association with HIV-1 susceptibility in a Chinese Han and a Chinese Uyghur cohort. METHODOLOGY/PRINCIPAL FINDINGS: Our cohort included 327 Han and 161 Uyghur ethnic individuals. Each cohort included HIV-1 seropositive and HIV-1 seronegative subjects. Four-digit HLA class I typing was performed by sequencing-based typing and high-resolution PCR-sequence specific primer. We compared the HLA class I allele and inferred haplotype frequencies between HIV-1 seropositive and seronegative groups. A neighbor-joining tree between our cohorts and other populations was constructed based on allele frequencies of HLA-A and HLA-B loci. We identified 58 HLA-A, 75 HLA-B, and 32 HLA-Cw distinct alleles from our cohort and no novel alleles. The frequency of HLA-B*5201 and A*0301 was significantly higher in the Han HIV-1 negative group. The frequency of HLA-B*5101 was significantly higher in the Uyghur HIV-1 negative group. We observed statistically significant increases in expectation-maximization (EM algorithm predicted haplotype frequencies of HLA-A*0201-B*5101 in the Uyghur HIV-1 negative group, and of Cw*0304-B*4001 in the Han HIV-1 negative group. The B62s supertype frequency was found to be significantly higher in the Han HIV-1 negative group than in the Han HIV-1 positive group. CONCLUSIONS: At the four-digit level, several HLA class I alleles and haplotypes were associated with lower HIV-1 susceptibility. Homogeneity of HLA class I and Bw4/Bw6 heterozygosity were not associated with HIV-1 susceptibility in our cohort. These observations contribute to the Chinese HLA database and could prove useful in the

  13. Ligation of major histocompatibility complex class I antigens (MHC-I) prevents apoptosis induced by Fas or SAPK/JNK activation in T-lymphoma cells

    Lamberth, K; Claesson, M H


    Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti......-apoptotic Bcl-2 protein and stabilized the mitochondrial membrane potential (Deltapsim). MHC-I ligation also prevented downregulation of Bcl-2 and destabilization of Deltapsim induced by anti-Fas Ab treatment or anisomycin exposure. Studies on three different Jurkat cell mutants deficient for src p56(lck), ZAP......-70 kinase, or TCR/CD3 gamma-chain showed that the cells undergo apoptosis after Fas ligation. Anisomycin exposure induced apoptosis in the src p56(lck)-deficient cell line but not in the two other mutant cell lines. Simultaneous cross-linking of MHC-I and Fas ligation inhibited apoptosis in the ZAP...

  14. The interaction between beta 2-microglobulin (beta 2m) and purified class-I major histocompatibility (MHC) antigen

    Pedersen, L O; Hansen, A S; Olsen, A C;


    been generated recently and this paper reports on a similar assay for the interaction between beta 2m and class I. As a model system human beta 2m binding to mouse class I was used. The assay is strictly biochemical using purified reagents which interact in solution and complex formation is determined...... by size separation. It is specific and highly sensitive. The observed affinity of the interaction, KD, is close to 0.4 nM. The rate of association at 37 degrees C is very fast (the ka is around 5 x 10(4)/M/s) whereas the dissociation is slow (the kd is around 8 x 10(-6)/s); the ratio of dissociation...

  15. Specificity for the tumor-associated self-antigen WT1 drives the development of fully functional memory T cells in the absence of vaccination.

    Pospori, Constandina; Xue, Shao-An; Holler, Angelika; Voisine, Cecile; Perro, Mario; King, Judith; Fallah-Arani, Farnaz; Flutter, Barry; Chakraverty, Ronjon; Stauss, Hans J; Morris, Emma C


    Recently, vaccines against the Wilms Tumor antigen 1 (WT1) have been tested in cancer patients. However, it is currently not known whether physiologic levels of WT1 expression in stem and progenitor cells of normal tissue result in the deletion or tolerance induction of WT1-specific T cells. Here, we used an human leukocyte antigen-transgenic murine model to study the fate of human leukocyte antigen class-I restricted, WT1-specific T cells in the thymus and in the periphery. Thymocytes expressing a WT1-specific T-cell receptor derived from high avidity human CD8 T cells were positively selected into the single-positive CD8 population. In the periphery, T cells specific for the WT1 antigen differentiated into CD44-high memory phenotype cells, whereas T cells specific for a non-self-viral antigen retained a CD44(low) naive phenotype. Only the WT1-specific T cells, but not the virus-specific T cells, displayed rapid antigen-specific effector function without prior vaccination. Despite long-term persistence of WT1-specific memory T cells, the animals did not develop autoimmunity, and the function of hematopoietic stem and progenitor cells was unimpaired. This is the first demonstration that specificity for a tumor-associated self-antigen may drive differentiation of functionally competent memory T cells. PMID:21447831

  16. A crypto-Dravidian origin for the nontribal communities of South India based on human leukocyte antigen class I diversity.

    Thomas, R; Nair, S B; Banerjee, M


    The Dravidian communities are considered to be the original inhabitants of India, now restricted to South India. The southern most state, Kerala, is socio-culturally stratified into Hindus, Muslims and Christians on the basis of religion. The origin of these religious communities in Kerala is considered to be unique in comparison with that in other parts of the country. These communities were later influenced by the hierarchical caste structure established by the Hindu Brahmins. In the present study, we compared six nontribal (Namboothiri, Nair, Ezhava, Pulaya, Malabar Muslim and Syrian Christian) communities belonging to the major religious groups in Kerala (Hindu, Muslim and Christian) based on the human leukocyte antigen (HLA)-A, -B and -C diversity. Our aim was to understand the genomic substructuring associated with the changing social scenario in various caste and religious groups and compare it with the Dravidian tribal and other world populations. The present study reveals that the HLA diversity of the Dravidian communities is very distinct from that in the other world populations. It is obvious that the nontribal communities of Kerala display a greater Dravidian influence, but traces of genetic admixture with the Mediterranean, western European, central Asian and East Asian populations can be observed. This characterizes the crypto-Dravidian features of the nontribal communities of Kerala. Demic diffusion of the local progressive communities with the migrant communities may have given rise to crypto-Dravidian features among the nontribal communities of Kerala. PMID:16948643

  17. Glutamic acid decarboxylase 65 and islet cell antigen 512/IA-2 autoantibodies in relation to human leukocyte antigen class II DR and DQ alleles and haplotypes in type 1 diabetes mellitus.

    Stayoussef, Mouna; Benmansour, Jihen; Al-Jenaidi, Fayza A; Said, Hichem B; Rayana, Chiheb B; Mahjoub, Touhami; Almawi, Wassim Y


    The frequencies of autoantibodies against glutamic acid decarboxylase 65 (GAD65) and islet cell antigen (ICA) 512/IA-2 (512/IA-2) are functions of the specific human leukocyte antigen (HLA) in type 1 diabetes mellitus (T1D). We investigated the association of HLA class II (DR and DQ) alleles and haplotypes with the presence of GAD and IA-2 autoantibodies in T1D. Autoantibodies were tested in 88 Tunisian T1D patients and 112 age- and gender-matched normoglycemic control subjects by enzyme immunoassay. Among T1D patients, mean anti-GAD antibody titers were higher in the DRB1*030101 allele (P < 0.001), together with the DRB1*030101/DQB1*0201 (P < 0.001) and DRB1*040101/DQB1*0302 (P = 0.002) haplotypes, while lower anti-GAD titers were associated with the DRB1*070101 (P = 0.001) and DRB1*110101 (P < 0.001) alleles and DRB1*070101/DQB1*0201 (P = 0.001) and DRB1*110101/DQB1*030101 (P = 0.001) haplotypes. Mean anti-IA-2 antibody titers were higher in the DRB1*040101 allele (P = 0.007) and DRB1*040101/DQB1*0302 (P = 0.001) haplotypes but were lower in the DRB1*110101 allele (P = 0.010) and the DRB1*110101 (P < 0.001) and DRB1*110101/DQB1*030101 (P = 0.025) haplotypes. Multinomial regression analysis confirmed the positive association of DRB1*030101 and the negative association of DRB1*110101 and DQB1*030101, along with the DRB1*070101/DQB1*0201 and DRB1*110101/DQB1*030101 haplotypes, with anti-GAD levels. In contrast, only the DRB1*040101/DQB1*0302 haplotype was positively associated with altered anti-IA-2 titers. Increased GAD65 and IA-2 antibody positivity is differentially associated with select HLA class II alleles and haplotypes, confirming the heterogeneous nature of T1D. PMID:21490167

  18. Glutamic Acid Decarboxylase 65 and Islet Cell Antigen 512/IA-2 Autoantibodies in Relation to Human Leukocyte Antigen Class II DR and DQ Alleles and Haplotypes in Type 1 Diabetes Mellitus ▿

    Stayoussef, Mouna; Benmansour, Jihen; Al-Jenaidi, Fayza A.; Said, Hichem B.; Rayana, Chiheb B.; Mahjoub, Touhami; Almawi, Wassim Y.


    The frequencies of autoantibodies against glutamic acid decarboxylase 65 (GAD65) and islet cell antigen (ICA) 512/IA-2 (512/IA-2) are functions of the specific human leukocyte antigen (HLA) in type 1 diabetes mellitus (T1D). We investigated the association of HLA class II (DR and DQ) alleles and haplotypes with the presence of GAD and IA-2 autoantibodies in T1D. Autoantibodies were tested in 88 Tunisian T1D patients and 112 age- and gender-matched normoglycemic control subjects by enzyme immunoassay. Among T1D patients, mean anti-GAD antibody titers were higher in the DRB1*030101 allele (P < 0.001), together with the DRB1*030101/DQB1*0201 (P < 0.001) and DRB1*040101/DQB1*0302 (P = 0.002) haplotypes, while lower anti-GAD titers were associated with the DRB1*070101 (P = 0.001) and DRB1*110101 (P < 0.001) alleles and DRB1*070101/DQB1*0201 (P = 0.001) and DRB1*110101/DQB1*030101 (P = 0.001) haplotypes. Mean anti-IA-2 antibody titers were higher in the DRB1*040101 allele (P = 0.007) and DRB1*040101/DQB1*0302 (P = 0.001) haplotypes but were lower in the DRB1*110101 allele (P = 0.010) and the DRB1*110101 (P < 0.001) and DRB1*110101/DQB1*030101 (P = 0.025) haplotypes. Multinomial regression analysis confirmed the positive association of DRB1*030101 and the negative association of DRB1*110101 and DQB1*030101, along with the DRB1*070101/DQB1*0201 and DRB1*110101/DQB1*030101 haplotypes, with anti-GAD levels. In contrast, only the DRB1*040101/DQB1*0302 haplotype was positively associated with altered anti-IA-2 titers. Increased GAD65 and IA-2 antibody positivity is differentially associated with select HLA class II alleles and haplotypes, confirming the heterogeneous nature of T1D. PMID:21490167

  19. MHC class II-associated invariant chain linkage of antigen dramatically improves cell-mediated immunity induced by adenovirus vaccines

    Holst, Peter Johannes; Mandrup Jensen, Camilla Maria; Orskov, Cathrine; Thomsen, Allan Randrup; Christensen, Jan Pravsgaard; Sørensen, Maria Rathmann


    potent and versatile Ag delivery vehicles available. However, the impact of chronic infections like HIV and hepatitis C virus underscore the need for further improvements. In this study, we show that the protective immune response to an adenovirus-encoded vaccine Ag can be accelerated, enhanced......, broadened, and prolonged by tethering of the rAg to the MHC class II-associated invariant chain (Ii). Thus, adenovirus-vectored vaccines expressing lymphocytic choriomeningitis virus (LCMV)-derived glycoprotein linked to Ii increased the CD4+ and CD8+ T cell stimulatory capacity in vitro and in vivo....... Furthermore, mice vaccinated with a single dose of adenovirus-expressing LCMV-derived glycoprotein linked to Ii were protected against lethal virus-induced choriomeningitis, lethal challenge with strains mutated in immunodominant T cell epitopes, and systemic infection with a highly invasive strain. In...

  20. The induction of cytotoxic T cells and tumor regression by soluble antigen formulation.

    Hariharan, K; Braslawsky, G; Black, A; Raychaudhuri, S; Hanna, N


    CTLs specific for tumor antigens play a major role in the immunity against cancer. We have shown that class I-restricted CTLs can be induced by injecting soluble antigens mixed in an antigen formulation (AF) that consists of squalane, Tween 80, and Pluronic L121 (S. Raychaudhuri et al., Proc. Natl. Acad. Sci. USA, 89: 8308-8312, 1992). In this study, using ovalbumin and the ovalbumin-expressing transfectoma (EG7) as a tumor model system, we examined the in vivo antitumor effect of antigen-AF mixture. Vaccination of mice with ovalbumin in AF 2 or 3 days after EG7 tumor challenge showed significant inhibition of tumor growth compared to mice vaccinated with ovalbumin in alum or in saline. Depletion of CD8+ cells at the time of immunization completely abrogated the AF-induced tumor protection, indicating that CD8+ T cells are the major effectors in tumor protection in vivo. Depletion of CD4+ cells led to a marginal loss of tumor protection, which may be the result of inhibition of ovalbumin-specific CTL response due to the lack of T-helper activity. Our results demonstrate that AF can be used in subunit vaccines to stimulate CTLs and tumor regression in vivo. PMID:7627951

  1. The non-structural protein Nsp2TF of porcine reproductive and respiratory syndrome virus down-regulates the expression of Swine Leukocyte Antigen class I.

    Cao, Qian M; Subramaniam, Sakthivel; Ni, Yan-Yan; Cao, Dianjun; Meng, Xiang-Jin


    Porcine reproductive and respiratory syndrome virus (PRRSV) is arguably the most economically-important global swine pathogen. Here we demonstrated that PRRSV down-regulates Swine Leukocyte Antigen class I (SLA-I) expression in porcine alveolar macrophages, PK15-CD163 cells and monocyte-derived dendritic cells. To identify the viral protein(s) involved in SLA-I down-regulation, we tested all 22 PRRSV structural and non-structural proteins and identified that Nsp1α and Nsp2TF, and GP3 significantly down-regulated SLA-I expression with Nsp2TF showing the greatest effect. We further generated a panel of mutant viruses in which the Nsp2TF protein synthesis was abolished, and found that the two mutants with disrupted -2 ribosomal frameshifting elements and additional stop codons in the TF domain were unable to down-regulate SLA-I expression. Additionally we demonstrated that the last 68 amino acids of TF domain in Nsp2TF are critical for this function. Collectively, the results indicate a novel function of Nsp2TF in negative modulation of SLA-I expression. PMID:26895249

  2. Measuring motion on DNA by the type I restriction endonuclease EcoR124I using triplex displacement

    Firman, Keith; Szczelkun, Mark D.


    The type I restriction enzyme EcoR124I cleaves DNA following extensive linear translocation dependent upon ATP hydrolysis. Using protein-directed displacement of a DNA triplex, we have determined the kinetics of one-dimensional motion without the necessity of measuring DNA or ATP hydrolysis. The triplex was pre-formed specifically on linear DNA, 4370 bp from an EcoR124I site, and then incubated with endonuclease. Upon ATP addition, a distinct lag phase was observed before the triplex-forming ...

  3. Characterization of DNA binding activities of over-expressed kpnI restriction endonuclease and modification methylase

    Chandrashekaran, Siddamadappa; Babu, Padmanabhan; Nagaraja, Valakunja


    The genes encoding the KpnI restriction endonuclease and methyltransferase from Klebsiella pneumoniae have been cloned and expressed in Escherchia coli using a two plasmid strategy. The gene for KpnI methylase with its promoter was cloned and expressed in pACYC184. Even though the methylase clone is in a low copy number plasmid pACMK, high level expression of methylase is achieved. A hyper-expressing clone of KpnI endonuclease, pETRK was engineered by cloning the R gene into the T7 expression...

  4. Host MHC class II+ antigen-presenting cells and CD4 cells are required for CD8-mediated graft-versus-leukemia responses following delayed donor leukocyte infusions

    Chakraverty, Ronjon; Eom, Hyeon-Seok; Sachs, Jessica; Buchli, Jennifer; Cotter, Pete; Hsu, Richard; Zhao, Guiling; Sykes, Megan


    Following bone marrow transplantation, delayed donor leukocyte infusions (DLIs) can induce graft-versus-leukemia (GVL) effects without graft-versus-host disease (GVHD). These antitumor responses are maximized by the presence of host hematopoietic antigen-presenting cells (APCs) at the time of DLI. Using a tumor-protection model, we demonstrate here that GVL activity following administration of DLIs to established mixed chimeras is dependent primarily on reactivity to allogeneic MHC antigens r...

  5. Relationship of human leukocyte antigen class Ⅱ genes with the susceptibility to hepatitis B virus infection and the response to interferon in HBV-infected patients

    Yong-Nian Han; Jin-Long Yang; Shui-Gen Zheng; Qun Tang; Wei Zhu


    AIM: To study the relationship of human leukocyte antigen (HLA)-DRB1 and -DQB1 alleles with the genetic susceptibility to HBV infection and the response to interferon (IFN) in HBV-infected patients.METHODS: Low-resolution DNA typing kit was used to determine HLA-DR-1 and -DQB1 genes in 72 patients with chronic hepatitis B (CHB) and HLA-DRB1 in 200 healthy people ready to donate their bone marrow in Shanghai.Among CHB patients, 35 were treated with IFNα-1b for 24 wk.RESULTS: The frequencies of HLA-DRB1*06, DRB1*08and DRB1*16 alleles in 72 patients were higher than in 200 healthy people (2.08% vs0%, OR = 3.837, P= 0.018;11.11% vs5.50%, OR = 2.148, P= 0.034; and 6.94% vs 3.00%, OR = 0.625, P = 0.049, respectively); whereas that of DRB1*07 allele was lower (2.78% vs 7.75%,OR = 0.340, P = 0.046). The frequency of HLA-DRB1* 14allele was higher in 11 responders to IFN compared with 24 non-responders (18.18% vs2.08%, OR = 10.444,P = 0.031), whereas that of DQB1*07 allele was inverse (9.09% vs 37.50%, OR = 0.167, P= 0.021).CONCLUSION: The polymorphism of HLA class Ⅱ may influence the susceptibility to HBV infection and the response to IFN in studied CHB patients. Compared with other HLA-DRB1 alleles, HLA-DRB1*06, DRB1*08, and DRB1*16 may be associated with chronicity of HBV infection, HLA-DRB1*07 with protection against HBV infection, and HLA-DRB1*14 allele may be associated with a high rate of the response of CHB patients to IFN treatment.Compared with other HLA-DQB1 alleles, HLA-DQB1*07 may be associated with low response rate to IFN.

  6. Macroautophagy Proteins Control MHC Class I Levels on Dendritic Cells and Shape Anti-viral CD8+ T Cell Responses

    Monica Loi


    Full Text Available The macroautophagy machinery has been implicated in MHC class II restricted antigen presentation. Here, we report that this machinery assists in the internalization of MHC class I molecules. In the absence of the autophagy factors Atg5 and Atg7, MHC class I surface levels are elevated due to decreased endocytosis and degradation. Internalization of MHC class I molecules occurs less efficiently if AAK1 cannot be recruited via Atg8/LC3B. In the absence of Atg-dependent MHC class I internalization, dendritic cells stimulate CD8+ T cell responses more efficiently in vitro and in vivo. During viral infections, lack of Atg5 results in enhanced influenza- and LCMV-specific CD8+ T cell responses in vivo. Elevated influenza-specific CD8+ T cell responses are associated with better immune control of this infection. Thus, the macroautophagy machinery orchestrates T cell immunity by supporting MHC class II but compromises MHC class I restricted antigen presentation.

  7. Macroautophagy Proteins Control MHC Class I Levels on Dendritic Cells and Shape Anti-viral CD8(+) T Cell Responses.

    Loi, Monica; Müller, Anne; Steinbach, Karin; Niven, Jennifer; Barreira da Silva, Rosa; Paul, Petra; Ligeon, Laure-Anne; Caruso, Assunta; Albrecht, Randy A; Becker, Andrea C; Annaheim, Nicolas; Nowag, Heike; Dengjel, Jörn; García-Sastre, Adolfo; Merkler, Doron; Münz, Christian; Gannagé, Monique


    The macroautophagy machinery has been implicated in MHC class II restricted antigen presentation. Here, we report that this machinery assists in the internalization of MHC class I molecules. In the absence of the autophagy factors Atg5 and Atg7, MHC class I surface levels are elevated due to decreased endocytosis and degradation. Internalization of MHC class I molecules occurs less efficiently if AAK1 cannot be recruited via Atg8/LC3B. In the absence of Atg-dependent MHC class I internalization, dendritic cells stimulate CD8(+) T cell responses more efficiently in vitro and in vivo. During viral infections, lack of Atg5 results in enhanced influenza- and LCMV-specific CD8(+) T cell responses in vivo. Elevated influenza-specific CD8(+) T cell responses are associated with better immune control of this infection. Thus, the macroautophagy machinery orchestrates T cell immunity by supporting MHC class II but compromises MHC class I restricted antigen presentation. PMID:27117419

  8. Simultaneous identification of Trypanosoma cruzi surface and internal antigens reactive to different immunoglobulin classes (radio-immunoblotting) Identificação simultânea de antígenos internos e de superfície de Trypanosoma cruzi reativos para diferentes classes de imunoglobulinas (radio-immunoblotting)

    Anna Maria Simonsen Stolf; Eufrosina Setsu Umezawa; Bianca Zingales


    A radioactive Western-blotting technique was developed by which the reactivity of Immunoglobulins (Igs) from different classes to both membrane radiolabelled and internal parasite antigens is simultaneously identified. The method includes radioiodination of parasites, polypeptide fractionation by SDS-PAGE, Western-blot transfer and autoradiography of the immunoblots developed with anti-Igs conjugates labelled with enzymes. The analysis is then performed by the comparison of common bands on th...

  9. Proteome-wide screening reveals immunodominance in the CD8 T cell response against classical swine fever virus with antigen-specificity dependent on MHC class I haplotype expression.

    Giulia Franzoni

    Full Text Available Vaccination with live attenuated classical swine fever virus (CSFV vaccines induces a rapid onset of protection which has been associated with virus-specific CD8 T cell IFN-γ responses. In this study, we assessed the specificity of this response, by screening a peptide library spanning the CSFV C-strain vaccine polyprotein to identify and characterise CD8 T cell epitopes. Synthetic peptides were pooled to represent each of the 12 CSFV proteins and used to stimulate PBMC from four pigs rendered immune to CSFV by C-strain vaccination and subsequently challenged with the virulent Brescia strain. Significant IFN-γ expression by CD8 T cells, assessed by flow cytometry, was induced by peptide pools representing the core, E2, NS2, NS3 and NS5A proteins. Dissection of these antigenic peptide pools indicated that, in each instance, a single discrete antigenic peptide or pair of overlapping peptides was responsible for the IFN-γ induction. Screening and titration of antigenic peptides or truncated derivatives identified the following antigenic regions: core₂₄₁₋₂₅₅ PESRKKLEKALLAWA and NS3₁₉₀₂₋₁₉₁₂ VEYSFIFLDEY, or minimal length antigenic peptides: E2₉₉₆₋₁₀₀₃ YEPRDSYF, NS2₁₂₂₃₋₁₂₃₀ STVTGIFL and NS5A₃₀₇₀₋₃₀₇₈ RVDNALLKF. The epitopes are highly conserved across CSFV strains and variable sequence divergence was observed with related pestiviruses. Characterisation of epitope-specific CD8 T cells revealed evidence of cytotoxicity, as determined by CD107a mobilisation, and a significant proportion expressed TNF-α in addition to IFN-γ. Finally, the variability in the antigen-specificity of these immunodominant CD8 T cell responses was confirmed to be associated with expression of distinct MHC class I haplotypes. Moreover, recognition of NS₁₂₂₃₋₁₂₃₀ STVTGIFL and NS3₁₉₀₂₋₁₉₁₂ VEYSFIFLDEY by a larger group of C-strain vaccinated animals showed

  10. Enhanced vaccine-induced CD8+ T cell responses to malaria antigen ME-TRAP by fusion to MHC class ii invariant chain.

    Alexandra J Spencer

    Full Text Available The orthodox role of the invariant chain (CD74; Ii is in antigen presentation to CD4+ T cells, but enhanced CD8+ T cells responses have been reported after vaccination with vectored viral vaccines encoding a fusion of Ii to the antigen of interest. In this study we assessed whether fusion of the malarial antigen, ME-TRAP, to Ii could increase the vaccine-induced CD8+ T cell response. Following single or heterologous prime-boost vaccination of mice with a recombinant chimpanzee adenovirus vector, ChAd63, or recombinant modified vaccinia virus Ankara (MVA, higher frequencies of antigen-specific CD4+ and CD8+ T cells were observed, with the largest increases observed following a ChAd63-MVA heterologous prime-boost regimen. Studies in non-human primates confirmed the ability of Ii-fusion to augment the T cell response, where a 4-fold increase was maintained up to 11 weeks after the MVA boost. Of the numerous different approaches explored to increase vectored vaccine induced immunogenicity over the years, fusion to the invariant chain showed a consistent enhancement in CD8+ T cell responses across different animal species and may therefore find application in the development of vaccines against human malaria and other diseases where high levels of cell-mediated immunity are required.

  11. Lack of association between Behçet's disease and major histocompatibility complex class II antigens in an ethnically diverse North American Caucasoid patient group.

    Moore, S B; O'Duffy, J D


    A group of 25 North American Caucasoid patients with well defined Behcet's disease were serologically typed for HLA-DR and DQw antigens. No significant associations were seen when results were compared with a group of 73 normal Caucasoid controls tested concomitantly. PMID:3772926

  12. The production and crystallization of the human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 complexed with deamidated gliadin peptides implicated in coeliac disease

    The production and crystallization of human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 in complex with deamidated gliadin peptides is reported. Crystals of HLA-DQ2PQPELPYPQ diffracted to 3.9 Å, while the HLA-DQ8EGSFQPSQE crystals diffracted to 2.1 Å, allowing structure determination by molecular replacement. The major histocompatibility complex (MHC) class II molecules HLA-DQ2 and HLA-DQ8 are key risk factors in coeliac disease, as they bind deamidated gluten peptides that are subsequently recognized by CD4+ T cells. Here, the production and crystallization of both HLA-DQ2 and HLA-DQ8 in complex with the deamidated gliadin peptides DQ2 α-I (PQPELPYPQ) and DQ8 α-I (EGSFQPSQE), respectively, are reported

  13. The production and crystallization of the human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 complexed with deamidated gliadin peptides implicated in coeliac disease

    Henderson, Kate N.; Reid, Hugh H.; Borg, Natalie A.; Broughton, Sophie E.; Huyton, Trevor [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); Anderson, Robert P. [Autoimmunity and Transplantation Division, Walter and Eliza Hall Institute, 1G Royal Parade, Parkville, Victoria 3050 (Australia); Department of Gastroenterology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050 (Australia); McCluskey, James [Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010 (Australia); Rossjohn, Jamie, E-mail: [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia)


    The production and crystallization of human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 in complex with deamidated gliadin peptides is reported. Crystals of HLA-DQ2{sup PQPELPYPQ} diffracted to 3.9 Å, while the HLA-DQ8{sup EGSFQPSQE} crystals diffracted to 2.1 Å, allowing structure determination by molecular replacement. The major histocompatibility complex (MHC) class II molecules HLA-DQ2 and HLA-DQ8 are key risk factors in coeliac disease, as they bind deamidated gluten peptides that are subsequently recognized by CD4{sup +} T cells. Here, the production and crystallization of both HLA-DQ2 and HLA-DQ8 in complex with the deamidated gliadin peptides DQ2 α-I (PQPELPYPQ) and DQ8 α-I (EGSFQPSQE), respectively, are reported.

  14. Transcription factor Fos-related antigen 1 is an effective target for a breast cancer vaccine

    Luo, Yunping; Zhou, He; Mizutani, Masato; Mizutani, Noriko; Reisfeld, Ralph A.; Xiang, Rong


    Protection against breast cancer was achieved with a DNA vaccine against murine transcription factor Fos-related antigen 1, which is overexpressed in aggressively proliferating D2F2 murine breast carcinoma. Growth of primary s.c. tumor and dissemination of pulmonary metastases was markedly suppressed by this oral DNA vaccine, carried by attenuated Salmonella typhimurium, encoding murine Fos-related antigen 1, fused with mutant polyubiquitin, and cotransformed with secretory murine IL-18. The life span of 60% of vaccinated mice was tripled in the absence of detectable tumor growth after lethal tumor cell challenge. Immunological mechanisms involved activation of T, natural killer, and dendritic cells, as indicated by up-regulation of their activation markers and costimulatory molecules. Markedly increased specific target cell lysis was mediated by both MHC class I-restricted CD8+ T cells and natural killer cells isolated from splenocytes of vaccinated mice, including a significant release of proinflammatory cytokines IFN- and IL-2. Importantly, fluorescence analysis of fibroblast growth factor 2 and tumor cell-induced vessel growth in Matrigel plugs demonstrated marked suppression of angiogenesis only in vaccinated animals. Taken together, this multifunctional DNA vaccine proved effective in protecting against growth and metastases of breast cancer by combining the action of immune effector cells with suppression of tumor angiogenesis. vaccine | tumor | metastases | antiangiogenesis

  15. Frequent lack of translation of antigen presentation-associated molecules MHC class I, CD1a and Beta(2)-microglobulin in Reed-Sternberg cells

    van den Berg, A.; Visser, L; Eberwine, J; Dadvand, L; Poppema, S


    Epstein-Barr virus (EBV) is present in Reed-Sternberg (RS) cells of a substantial proportion of Hodgkin's lymphoma cases. Most EBV-positive cases are also MHC class I-positive, whereas the majority of EBV-negative cases lack detectable levels of MHC class I expression. Application of the SAGE techni

  16. Bone Marrow Transplantation Results in Human Donor Blood Cells Acquiring and Displaying Mouse Recipient Class I MHC and CD45 Antigens on Their Surface

    Yamanaka, Nobuko; Wong, Christine J.; Gertsenstein, Marina; Robert F. Casper; Nagy, Andras; Rogers, Ian M.


    Background Mouse models of human disease are invaluable for determining the differentiation ability and functional capacity of stem cells. The best example is bone marrow transplants for studies of hematopoietic stem cells. For organ studies, the interpretation of the data can be difficult as transdifferentiation, cell fusion or surface antigen transfer (trogocytosis) can be misinterpreted as differentiation. These events have not been investigated in hematopoietic stem cell transplant models...

  17. Structural and functional analysis of the symmetrical Type I restriction endonuclease R.EcoR124I(NT.

    James E Taylor

    Full Text Available Type I restriction-modification (RM systems are comprised of two multi-subunit enzymes, the methyltransferase (∼160 kDa, responsible for methylation of DNA, and the restriction endonuclease (∼400 kDa, responsible for DNA cleavage. Both enzymes share a number of subunits. An engineered RM system, EcoR124I(NT, based on the N-terminal domain of the specificity subunit of EcoR124I was constructed that recognises the symmetrical sequence GAAN(7TTC and is active as a methyltransferase. Here, we investigate the restriction endonuclease activity of R. EcoR124I(NTin vitro and the subunit assembly of the multi-subunit enzyme. Finally, using small-angle neutron scattering and selective deuteration, we present a low-resolution structural model of the endonuclease and locate the motor subunits within the multi-subunit enzyme. We show that the covalent linkage between the two target recognition domains of the specificity subunit is not required for subunit assembly or enzyme activity, and discuss the implications for the evolution of Type I enzymes.

  18. Role of CD4 molecule in the induction of interleukin 2 and interleukin 2 receptor in class II major histocompatibility complex-restricted antigen-specific T helper clones. T cell receptor/CD3 complex transmits CD4-dependent and CD4-independent signals.

    Oyaizu, N; Chirmule, N; Pahwa, S.


    The CD4 molecule plays an essential role in antigen-induced activation of T helper (Th) cells, but its contribution to signal transduction events resulting in physiologic T cell function is ill defined. By utilizing anti-CD4 monoclonal antibodies (MAbs) that recognize distinct epitopes of CD4, we have investigated the role of CD4 molecule in antigen-induced interleukin 2 (IL-2) and IL-2 receptor (IL-2R) alpha chain expression in class II major histocompatibility complex-restricted antigen-spe...

  19. Swine Leukocyte Antigen (SLA) class I allele typing of Danish swine herds and the identification of commonly expressed haplotypes using sequence specific low- and high resolution primers

    Pedersen, Lasse Eggers; Fink, Dorte Rosenbek; Jungersen, Gregers

    The genomic region (SLA) of the swine major histocompatibility complex (MHC), which bind and present endogenous peptides to circulating T cells of the immune system, is extremely polymorphic comprising high numbers of different alleles, many of which encode a distinct MHC class I molecule. Each SLA...... individual. Therefore analyses of the prevalence of SLA alleles in a population are fundamental to employ pathogen-specific subunits or peptides in novel vaccines or immune diagnostics. In this study we present the use of low- and high-resolution PCR-based typing methods to identify individual and commonly...... expressed SLA class I alleles in Danish outbred swine. A total of 108 animals from eight different production herds were tested, and with low resolution sequence specific primer (SSP)-PCR typing the top five most commonly expressed SLA class I allele groups were found to be SLA-3*04XX, SLA-1*08XX, SLA-1...

  20. DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8(+) T Cell Responses, Enabling Faster Resolution of Influenza Disease.

    Lambert, Laura; Kinnear, Ekaterina; McDonald, Jacqueline U; Grodeland, Gunnveig; Bogen, Bjarne; Stubsrud, Elisabeth; Lindeberg, Mona M; Fredriksen, Agnete Brunsvik; Tregoning, John S


    Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine-induced protection. While it is clear that antibodies play a protective role, vaccine-induced CD8(+) T cells can improve protection. To further explore the role of CD8(+) T cells, we used a DNA vaccine that encodes antigen dimerized to an immune cell targeting module. Immunizing CB6F1 mice with the DNA vaccine in a heterologous prime-boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared with protein alone. This improved disease resolution was dependent on CD8(+) T cells. However, DNA vaccine regimes that induced CD8(+) T cells alone were not protective and did not boost the protection provided by protein. The MHC-targeting module used was an anti-I-E(d) single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting, we compared the response between BALB/c, C57BL/6 mice, and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not, and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that, in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines. PMID:27602032

  1. Swine Leukocyte Antigen (SLA) class I allele typing of Danish swine herds and identification of commonly occurring haplotypes using sequence specific low and high resolution primers

    Pedersen, Lasse Eggers; Jungersen, Gregers; Sørensen, Maria Rathmann;


    The swine major histocompatibility complex (MHC) genomic region (SLA) is extremely polymorphic comprising high numbers of different alleles, many encoding a distinct MHC class I molecule, which binds and presents endogenous peptides to circulating T cells of the immune system. Upon recognition of...... such peptide-MHC complexes (pMHC) naïve T cells can become activated and respond to a given pathogen leading to its elimination and the generation of memory cells. Hence SLA plays a crucial role in maintaining overall adaptive immunologic resistance to pathogens. Knowing which SLA alleles that are......, vesicular stomatitis virus, foot-and-mouth-disease virus and others. Here we present the use of low- and high-resolution PCR-based typing methods to identify individual and commonly occurring SLA class I alleles in Danish swine. A total of 101 animals from seven different herds were tested, and by low...

  2. Swine Leukocyte Antigen (SLA) class I allele typing of Danish swine herds and the identification of commonly expressed haplotypes using sequence specific low- and high resolution primers

    Pedersen, Lasse Eggers; Fink, Dorte Rosenbek; Jungersen, Gregers


    The genomic region (SLA) of the swine major histocompatibility complex (MHC), which bind and present endogenous peptides to circulating T cells of the immune system, is extremely polymorphic comprising high numbers of different alleles, many of which encode a distinct MHC class I molecule. Each SLA molecule is only able to bind a restricted number of peptides with specific biochemical characteristics matching important anchor positions in the peptide binding groove. Although the diversity of ...

  3. Quantificação de antígenos HLA classe I solúveis pela técnica de ELISA - DOI: 10.4025/actascihealthsci.v31i2.6758 Quantification of soluble HLA class I antigens by ELISA assay- DOI: 10.4025/actascihealthsci.v31i2.6758

    Marciele Coan Boian


    Full Text Available As moléculas HLA (Human Leucocyte Antigens são consideradas, principalmente, estruturas de superfície celular envolvidas em uma variedade de reações imunes associadas com transplante, infecções e doenças autoimunes. Os antígenos HLA também podem ser encontrados, em forma solúvel, no soro e em diferentes fluidos do organismo humano. Este trabalho teve como objetivo desenvolver a técnica imunoenzimática (ELISA para quantificar os níveis séricos de antígenos HLA classe I, específicos e totais, em indivíduos normais e em pacientes renais. A técnica de ELISA foi desenvolvida para demonstrar a presença, no soro, de antígenos HLA classe I totais (sHLA-I e as especificidades HLA-A2 (sHLA-A2 e HLA-B7 (sHLA-B7. Oitenta e oito amostras de soro foram envolvidas neste estudo, sendo 61 amostras provenientes de indivíduos sadios cadastrados no Hemocentro Regional de Maringá, Estado do Paraná, e 27 pacientes renais, provenientes dos centros de diálise da cidade de Maringá, Estado do Paraná. As concentrações médias de sHLA para as especificidades -A2 e -B7, detectadas somente em indivíduos sadios, foram 504.06 ng mL-1 ± 142.10 e 427.33 ng mL-1 ± 140.73, respectivamente. Resultados preliminares mostraram que sHLA-I, em indivíduos sadios, foi de 253,77 ng mL-1 e, em indivíduos renais em diálise, de 381,67 ng mL-1. A técnica de ELISA para detecção de antígenos HLA solúveis poderá ser útil em estudos comparativos, em diferentes populações saudáveis, diferentes patologias e no monitoramento das rejeições em transplantes.HLA (Human Leucocyte Antigens molecules are regarded mainly as cell surface structures involved in several immune reactions associated with transplants, infections and auto-immune diseases. HLA antigens can be also found in soluble form in serum and in different fluids of the human body. The aim of this work was to develop the immunoenzymatic assay (ELISA to quantify serum levels of specific and total

  4. Antigen-specific CD4+ T cells regulate function of myeloid-derived suppressor cells in cancer via retrograde MHC class II signaling

    Nagaraj, Srinivas; Nelson, Allison; Youn, Je-in; Cheng, Pingyan; Quiceno, David; Gabrilovich, Dmitry I.


    Myeloid-derived suppressor cells (MDSC) play a major role in cancer-related immune suppression, yet the nature of this suppression remains controversial. In this study, we evaluated the ability of MDSC to elicit CD4+ T cell tolerance in different mouse tumor models. In contrast to CD8+ T-cell tolerance, which could be induced by MDSC in all the tumor models tested, CD4+ T-cell tolerance could be elicited in only one of the models (MC38) where a substantial level of MHC class II was expressed ...

  5. Peptide-loaded dendritic cells prime and activate MHC-class I-restricted T cells more efficiently than protein-loaded cross-presenting DC

    Met, Ozcan; Buus, Søren; Claesson, Mogens H


    Undifferentiated and differentiated dendritic cells (uDC and dDC, respectively), derived from the bone marrow, were studied in vitro and in vivo. Ovalbumin (OVA) and two OVA-derived peptides binding to H-2K(b) and I-A(b), respectively, were used. Two IL-2 secreting T cell hybridomas specific for...

  6. Characterization of antigens of the dog major histocompatibility complex

    Feltz, Machteld


    textabstractIn this thesis, an immunochemical analysis of dog Major Histocompatibility Complex (MHC) antigens, also called DLA antigens, is described. MHC antigens play a prominent role in the immune system, particularly in the recognition of foreign material. They can be divided into four classes. As only DLA class I antigens have been defined by well characterized reagents (antisera), they were chosen as the object of the investigation

  7. The central repeat domain 1 of Kaposi's sarcoma-associated herpesvirus (KSHV) latency associated-nuclear antigen 1 (LANA1) prevents cis MHC class I peptide presentation

    KSHV LANA1, a latent protein expressed during chronic infection to maintain a viral genome, inhibits major histocompatibility complex class I (MHC I) peptide presentation in cis as a means of immune evasion. Through deletional cloning, we localized this function to the LANA1 central repeat 1 (CR1) subregion. Other CR subregions retard LANA1 translation and proteasomal processing but do not markedly inhibit LANA1 peptide processing by MHC I. Inhibition of proteasomal processing ablates LANA1 peptide presentation. Direct expression of LANA1 within the endoplasmic reticulum (ER) overcomes CR1 inhibition suggesting that CR1 acts prior to translocation of cytoplasmic peptides into the ER. By physically separating CR1 from other subdomains, we show that LANA1 evades MHC I peptide processing by a mechanism distinct from other herpesviruses including Epstein-Barr virus (EBV). Although LANA1 and EBV EBNA1 are functionally similar, they appear to use different mechanisms to evade host cytotoxic T lymphocyte surveillance.

  8. A modern approach for epitope prediction: identification of foot-and-mouth disease virus peptides binding bovine leukocyte antigen (BoLA) class I molecules

    Pandya, Mital; Rasmussen, Michael; Hansen, Andreas;


    pathogens, such as foot-and-mouth disease virus (FMDV). Six synthetic BoLA class I (BoLA-I) molecules were produced, and the peptide binding motif was generated for five of the six molecules using a combined approach of positional scanning combinatorial peptide libraries (PSCPLs) and neural network......-based predictions (NetMHCpan). The updated NetMHCpan server was used to predict BoLA-I binding peptides within the P1 structural polyprotein sequence of FMDV (strain A24 Cruzeiro) for BoLA-1*01901, BoLA-2*00801, BoLA-2*01201, and BoLA-4*02401. Peptide binding affinity and stability were determined for these Bo....... The results of these analyses showed that BoLA alleles cluster into three distinct groups with the potential to define “BoLA supertypes.” This streamlined approach identifies potential T cell epitopes from pathogens, such as FMDV, and provides insight into T cell immunity following infection or vaccination....

  9. Involvement of class II phosphoinositide 3-kinase α-isoform in antigen-induced degranulation in RBL-2H3 cells.

    Kiyomi Nigorikawa

    Full Text Available In this study, we present findings that suggest that PI3K-C2α, a member of the class II phosphoinositide 3-kinase (PI3K subfamily, regulates the process of FcεRI-triggered degranulation. RBL-2H3 cells were transfected with shRNA targeting PI3K-C2α. The knockdown impaired the FcεRI-induced release of a lysosome enzyme, β-hexosaminidase, without affecting the intracellular Ca2+ mobilization. The release of mRFP-tagged neuropeptide-Y, a reporter for the regulated exocytosis, was also decreased in the PI3K-C2α-deficient cells. The release was increased significantly by the expression of the siRNA-resistant version of PI3K-C2α. In wild-type cells, FcεRI stimulation induced the formation of large vesicles, which were associated with CD63, a marker protein of secretory granules. On the vesicles, the existence of PI3K-C2α and PtdIns(3,4P2 was observed. These results indicated that PI3K-C2α and its product PtdIns(3,4P2 may play roles in the secretory process.

  10. Immunogenicity of HLA Class I and II Double Restricted Influenza A-Derived Peptides

    Pedersen, Sara Ram; Christensen, Jan Pravsgaard; Buus, Søren;


    The aim of the present study was to identify influenza A-derived peptides which bind to both HLA class I and -II molecules and by immunization lead to both HLA class I and class II restricted immune responses. Eight influenza A-derived 9-11mer peptides with simultaneous binding to both HLA-A*02:0...... both HLA class I and class I restricted responses, a quality which might be of potential interest for peptide-based vaccine development....

  11. Deletion of naïve T cells recognizing the minor histocompatibility antigen HY with toxin-coupled peptide-MHC class I tetramers inhibits cognate CTL responses and alters immunodominance

    Hess, Sabrina M.; Young, Ellen F.; Miller, Keith R.; Vincent, Benjamin G.; Buntzman, Adam S.; Collins, Edward J.; Frelinger, Jeffrey A.; Hess, Paul R.


    Alloreactive T-cell responses directed against minor histocompatibility (H) antigens, which arise from diverse genetic disparities between donor and recipient outside the MHC, are an important cause of rejection of MHC-matched grafts. Because clinically significant responses appear to be directed at only a few antigens, the selective deletion of naïve T cells recognizing donor-specific, immunodominant minor H antigens in recipients before transplantation may be a useful tolerogenic strategy. ...

  12. The T210M Substitution in the HLA-a*02:01 gp100 Epitope Strongly Affects Overall Proteasomal Cleavage Site Usage and Antigen Processing.

    Textoris-Taube, Kathrin; Keller, Christin; Liepe, Juliane; Henklein, Petra; Sidney, John; Sette, Alessandro; Kloetzel, Peter M; Mishto, Michele


    MHC class I-restricted epitopes, which carry a tumor-specific mutation resulting in improved MHC binding affinity, are preferred T cell receptor targets in innovative adoptive T cell therapies. However, T cell therapy requires efficient generation of the selected epitope. How such mutations may affect proteasome-mediated antigen processing has so far not been studied. Therefore, we analyzed by in vitro experiments the effect on antigen processing and recognition of a T210M exchange, which previously had been introduced into the melanoma gp100209-217 tumor epitope to improve the HLA-A*02:01 binding and its immunogenicity. A quantitative analysis of the main steps of antigen processing shows that the T210M exchange affects proteasomal cleavage site usage within the mutgp100201-230 polypeptide, leading to the generation of an unique set of cleavage products. The T210M substitution qualitatively affects the proteasome-catalyzed generation of spliced and non-spliced peptides predicted to bind HLA-A or -B complexes. The T210M substitution also induces an enhanced production of the mutgp100209-217 epitope and its N-terminally extended peptides. The T210M exchange revealed no effect on ERAP1-mediated N-terminal trimming of the precursor peptides. However, mutant N-terminally extended peptides exhibited significantly increased HLA-A*02:01 binding affinity and elicited CD8(+) T cell stimulation in vitro similar to the wtgp100209-217 epitope. Thus, our experiments demonstrate that amino acid exchanges within an epitope can result in the generation of an altered peptide pool with new antigenic peptides and in a wider CD8(+) T cell response also towards N-terminally extended versions of the minimal epitope. PMID:26507656

  13. Crystallization and preliminary X-ray diffraction analysis of the HsdR subunit of a putative type I restriction enzyme from Vibrio vulnificus YJ016

    The crystallization of the HsdR subunit of a putative type I restriction-modification system from V. vulnificus and the collection of diffraction data to 2.6 Å resolution are reported. Type I restriction enzymes are multimeric proteins that consist of three subunits. The HsdS and HsdM subunits form a complex protein that shows methyltransferase activity, while the HsdR subunit functions as an endonuclease as well as as a translocase. Of these three subunits, no structural information on the HsdR subunit is yet available. The putative HsdR gene from Vibrio vulnificus YJ016 (HsdR-Vv) was cloned and expressed and the expressed protein HsdR-Vv was purified. HsdR-Vv was crystallized from 8%(w/v) polyethylene glycol 3350, 0.15 M ammonium chloride, 0.1 M HEPES pH 7.5 and 2 mM β-mercaptoethanol. Diffraction data were collected to 2.60 Å resolution using synchrotron radiation. The crystal belongs to the orthorhombic space group P212121, with unit-cell parameters a = 71.01, b = 89.04, c = 113.66 Å. With one HsdR-Vv molecule in the asymmetric unit, the Matthews coefficient was 2.14 Å3 Da−1 and the solvent content was 42%

  14. Participation of L3T4 in T cell activation in the absence of class II major histocompatibility complex antigens. Inhibition by anti-L3T4 antibodies is a function both of epitope density and mode of presentation of anti-receptor antibody

    Owens, T; Fazekas de St Groth, B


    activation in the complete absence of class II MHC, immobilized antibody (either Sepharose-coupled or plastic-adsorbed) being more effective. The induction of IL 3 production by suboptimal doses of either Con A or plastic-adsorbed F23.1 was inhibited by the anti-L3T4 antibody GK1.5, as was the response to F...... of T cell/antigen interactions. By using antibodies against the T cell antigen receptor (TCR) to activate T cells, thereby circumventing the requirement for antigen presenting cells and MHC-associated antigen, we have been able to study the function of L3T4 in the absence of class II MHC. We have...... used two monoclonal antibodies, KJ16-133.18 and F23.1, that recognize a determinant encoded by the T cell receptor V beta 8 gene family. These antibodies were used to select two clones of T cells with surface phenotype Thy-1.2+, L3T4+, Lyt-2-, KJ16-133.18+, F23.1+, IA-, IE-. One of these clones (E9.D4...

  15. Barriers to antigenic escape by pathogens: trade-off between reproductive rate and antigenic mutability

    Bush Robin M


    Full Text Available Abstract Background A single measles vaccination provides lifelong protection. No antigenic variants that escape immunity have been observed. By contrast, influenza continually evolves new antigenic variants, and the vaccine has to be updated frequently with new strains. Both measles and influenza are RNA viruses with high mutation rates, so the mutation rate alone cannot explain the differences in antigenic variability. Results We develop a new hypothesis to explain antigenic stasis versus change. We first note that the antigenically static viruses tend to have high reproductive rates and to concentrate infection in children, whereas antigenically variable viruses such as influenza tend to spread more widely across age classes. We argue that, for pathogens in a naive host population that spread more rapidly in younger individuals than in older individuals, natural selection weights more heavily a rise in reproductive rate. By contrast, pathogens that spread more readily among older individuals gain more by antigenic escape, so natural selection weights more heavily antigenic mutability. Conclusion These divergent selective pressures on reproductive rate and antigenic mutability may explain some of the observed differences between pathogens in age-class bias, reproductive rate, and antigenic variation.

  16. Antigen-Specific CD4+ T Cells Recognize Epitopes of Protective Antigen following Vaccination with an Anthrax Vaccine

    Laughlin, Elsa M.; Miller, Joseph D.; James, Eddie; Fillos, Dimitri; Ibegbu, Chris C.; Mittler, Robert S.; Akondy, Rama; Kwok, William; Ahmed, Rafi; Nepom, Gerald,


    Detection of antigen-specific CD4+ T cells is facilitated by the use of fluorescently labeled soluble peptide-major histocompatibility complex (MHC) multimers which mirror the antigen specificity of T-cell receptor recognition. We have used soluble peptide-MHC class II tetramers containing peptides from the protective antigen (PA) of Bacillus anthracis to detect circulating T cells in peripheral blood of subjects vaccinated with an anthrax vaccine. PA-specific HLA class II-restricted T lympho...

  17. Carcinoma-associated antigens

    This invention relates to novel antigens associated with breast carcinoma, anti-sera specific to said antigens, 125I-labeled forms of said antigens and methods of detecting said antigens in serum or plasma. The invention also relates to a diagnostic kit containing standardised antigens or antisera or marked forms thereof for the detection of said antigens in human blood, serum or plasma. (author)

  18. Aloimunidade contra antígenos HLA de classe I em pacientes com síndromes mielodisplásicas e anemia aplástica Aloimmunity against HLA class I antigens in patients with myelodisplastic syndrome and aplastic anemia

    Daisy M. M. Arruda


    Full Text Available As síndromes mielodisplásicas (SMD e a anemia aplástica (AA apresentam citopenias periféricas necessitando, com freqüência, de reposições transfusionais contínuas de concentrados de hemácias e/ou de concentrados de plaquetas. O objetivo do presente estudo foi verificar a ocorrência de anticorpos anti-HLA de classe I em pacientes portadores das SMD e AA atendidos no ambulatório de Hematologia do Hemoce/UFC. Foram analisados 110 pacientes, sendo 70 com SMD e 40 com AA. A pesquisa de anticorpos anti-HLA de classe I foi realizada frente a um painel (PRA, utilizando-se a técnica de microlinfocitotoxicidade dependente do complemento. Vinte (28,6% dos 70 pacientes com as SMD e 18 (45% dos 40 pacientes com AA desenvolveram anticorpos anti-HLA contra o PRA. Esses pacientes que receberam uma carga de antígenos estranhos advindos de múltiplas transfusões de vários doadores de CH e/ou CP, geralmente desenvolvem aloanticorpos contra os antígenos HLA presentes na superfície das plaquetas e dos leucócitos que contaminam esses concentrados. A produção desses anticorpos pode trazer sérias complicações para o tratamento dos pacientes com SMD e AA. As avaliações sistemáticas para detecção de anticorpos anti-HLA após a reposição transfusional podem ser valiosas para adoção de estratégias transfusionais mais adequadas para esta população de pacientes.Patients with myelodysplastic syndromes (MDS or aplastic anemia (AA present peripheral cytopenias and require continuous transfusions of red cell and/or platelet concentrates. The objective of this study is to verify the existence of anti-HLA class 1 antibodies in patients with MDS and AA treated at the hematology Out patient Clinic of Hemoce/UFC. A total of 110 patients were analyzed, 70 with MDS and 40 with AA. Anti-HLA class 1 antibody detection was achieved with an antibody reactivity panel using the complement-dependent microlymphocytotoxicity technique. A total of 20 (28.6% of

  19. [HLA and keloids: antigenic frequency and therapeutic response].

    Rossi, A; Bozzi, M


    Twenty keloid subjects were typed for class 1 (HLA-A, B and C) and class 2 (HLA-DR and DQ) histocompatibility antigens. Their frequencies were compared to those found in control populations. Of all the antigens belonging to class 1, B 21 was more prevalent in patients. The findings regarding class 2 antigens were noteworthy: in keloid patients there was a significant prevalence of DR 5 (RR = 3.54 and 7.93 respectively for the two control groups) and DQw 3 (RR = 16.8). The patients typed for HLA-antigens were treated with corticosteroid infiltrations. The responses to the treatments were no related to the histocompatibility antigens. PMID:2628278

  20. Recombinant parvovirus-like particles as an antigen carrier: A novel nonreplicative exogenous antigen to elicit protective antiviral cytotoxic T cells

    Sedlik, C.; Saron, M.-F.; Sarraseca, J.; Casal, I; Leclerc, C.


    To develop a strategy that promotes efficient antiviral immunity, hybrid virus-like particles (VLP) were prepared by self-assembly of the modified porcine parvovirus VP2 capsid protein carrying a CD8+ T cell epitope from the lymphocytic choriomeningitis virus nucleoprotein. Immunization of mice with these hybrid pseudoparticles, without adjuvant, induced strong cytotoxic T lymphocyte (CTL) responses against both peptide-coated- or virus-infected-target cells. This CD8+ class I-restricted cyto...

  1. Pst I restriction fragment length polymorphism of human placental alkaline phosphatase gene: Mendelian in segregation and localization of mutation site in the gene

    The pattern of inheritance of a Pst I restriction fragment length polymorphism (RFLP) of the human placental alkaline phosphatase gene was studied in nine nuclear families by Southern blot hybridization analysis of genomic DNA. The dimorphic RFLP is defined by the presence of allelic fragments 1.0 kilobase and 0.8 kilobase long. The results of this study show that the two alleles of the Pst I RFLP of the placental alkaline phosphatase gene segregate as codominant traits according to Mendelian expectations. For a polymorphism to be useful as a genetic marker the probability that an offspring is informative (PIC) must be at least 0.15. The allelic frequency of the 1.0-kilobase allele is 0.21, which correlates to a probability that an offspring is informative of 0.275 and is indicative of a useful polymorphism. By using probes derived from different regions of the placental alkaline phosphatase cDNA, the mutated Pst I site causing the RFLP was located in the penultimate intron 2497 base pairs downstream from the transcriptional initiation site

  2. Immunoprotective activity of a Salmonid Alphavirus Vaccine: comparison of the immune responses induced by inactivated whole virus antigen formulations based on CpG class B oligonucleotides and poly I:C alone or combined with an oil adjuvant.

    Thim, Hanna L; Iliev, Dimitar B; Christie, Karen E; Villoing, Stéphane; McLoughlin, Marian F; Strandskog, Guro; Jørgensen, Jorunn B


    CpG oligonucleotides and polyinosinic:polycytidylic acid (poly I:C) are toll-like receptor (TLR) agonists that mimic the immunostimulatory properties of bacterial DNA and double-stranded viral RNA respectively, and which have exhibited potential to serve as vaccine adjuvants in previous experiments. Here, a combination of CpGs and poly I:C together with water- or oil-formulated Salmonid Alphavirus (SAV) antigen preparations has been used for a vaccine in Atlantic salmon and tested for protection in SAV challenge trial. The results demonstrate that vaccination with a high dose of the SAV antigen induced protection against challenge with SAV which correlated with production of neutralizing antibodies (NAbs). As the high antigen dose alone induced full protection, no beneficial effect from the addition of CpG and poly I:C could be observed. Nevertheless, these TLR ligands significantly enhanced the levels of NAbs in serum of vaccinated fish. Interestingly, gene expression analysis demonstrated that while addition of oil suppressed the CpG/poly I:C-induced expression of IFN-γ, the upregulation of IFNa1 was substantially enhanced. A low dose of the SAV antigen combined with oil did not induce any detectable levels of NAbs either with or without TLR ligands present, however the addition of CpG and poly I:C to the low SAV antigen dose formulation significantly enhanced the protection against SAV suggesting that CpG/poly I:C may have enhanced a cytotoxic response - a process which is dependent on the up-regulation of type I IFN. These results highlight the immunostimulatory properties of the tested TLR ligands and will serve as a ground for further, more detailed studies aimed to investigate their capacity to serve as adjuvants in vaccine formulations for Atlantic salmon. PMID:22634299

  3. Histocompatibility antigen test

    ... more common in certain autoimmune diseases . For example, HLA-B27 antigen is found in many people (but not ... More Ankylosing spondylitis Autoimmune disorders Bone marrow transplant HLA-B27 antigen Kidney transplant Reactive arthritis Update Date 2/ ...

  4. Repair of x-ray-induced DNA double-strand breaks in specific Not I restriction fragments in human fibroblasts: joining of correct and incorrect ends

    Lobrich, M.; Rydberg, B.; Cooper, P. K.; Chatterjee, A. (Principal Investigator)


    An assay that allows measurement of absolute induction frequencies for DNA double-strand breaks (dsbs) in defined regions of the genome and that quantitates rejoining of correct DNA ends has been used to study repair of dsbs in normal human fibroblasts after x-irradiation. The approach involves hybridization of single-copy DNA probes to Not I restriction fragments separated according to size by pulsed-field gel electrophoresis. Induction of dsbs is quantitated from the decrease in the intensity of the hybridizing restriction fragment and an accumulation of a smear below the band. Rejoining of dsbs results in reconstitution of the intact restriction fragment only if correct DNA ends are joined. By comparing results from this technique with results from a conventional electrophoresis assay that detects all rejoining events, it is possible to quantitate the misrejoining frequency. Three Not I fragments on the long arm of chromosome 21 were investigated with regard to dsb induction, yielding an identical induction rate of 5.8 X 10(-3) break per megabase pair per Gy. Correct dsb rejoining was measured for two of these Not I fragments after initial doses of 80 and 160 Gy. The misrejoining frequency was about 25% for both fragments and was independent of dose. This result appears to be representative for the whole genome as shown by analysis of the entire Not I fragment distribution. The correct rejoining events primarily occurred within the first 2 h, while the misrejoining kinetics included a much slower component, with about half of the events occurring between 2 and 24 h. These misrejoining kinetics are similar to those previously reported for production of exchange aberrations in interphase chromosomes.

  5. An efficient fusion protein system for expression ofBacillus anthracis protective antigen as immunogenic and diagnostic antigen

    Vahid Bagheri; Hossein Motamedi; Masoud Reza Seifiabad Shapouri


    Objective:To produce high quantities of recombinant protective antigen (rPA) for human vaccine and diagnosis.Methods: ThePAgene was amplified byPCR with pXO1 plasmid as template. ThePCR product was cloned into pMAL-c2X vector using theBamHI andSalI restriction enzymes. The recombinant plasmid was transformed intoEscherichia coliDH5α strain and then screened for transformation. The expression of protective antigen was analyzed bySDS-PAGE and Western blotting after isopropyl β-D-thiogalactopyranoside(IPTG) induction.Results:The full-length PA gene (2.2kb) was cloned into pMAL vector system. The recombinant vector was confirmed by restriction enzyme andPCRanalysis. The expression of cytoplasmic maltose-binding protein-protective (MBP-P) antigen fusion protein was detected bySDS-PAGE and Western blotting, and obtained a125 kDa protein band, which was similar to expected size of fusion protein.Conclusions: This expression system can be used in the high production of rPA. After purification and immunization studies, the purified rPA may be used in the development of the human recombinant anthrax vaccine and also in diagnosis of anthrax disease.

  6. Autologous CD4 T-cell responses to ectopic class II major histocompatibility complex antigen-expressing single-cell islet cells: an in vitro insight into the pathogenesis of lymphocytic insulitis in nonobese diabetic mice.

    Formby, B; Miller, N.


    We investigated by flow cytometric analysis the expression of class II major histocompatibility complex (MHC) molecules by viable single-cell islet cells (SCICs) prepared from male and female 4- and 10-week-old nonobese diabetic (NOD) mouse islets. With anti-I-Ak monoclonal antibody (specific for I-Ak,f,r,s beta and produced by clone 11-5-2), and fluorescein isothiocyanate-conjugated goat anti-mouse IgG as second-step antibody, we found that SCICs from both sexes aberrantly expressed class II...

  7. Identification of peptides from foot‐and‐mouth disease virus structural proteins bound by class I swine leukocyte antigen (SLA) alleles, SLA‐1*0401 and SLA‐2*0401

    Pedersen, Lasse Eggers; Harndahl, M.; Nielsen, Morten; Patch, J. R.; Jungersen, Gregers; Buus, S.; Golde, W. T.


    within the structural proteins of foot‐and‐mouth disease virus (FMDV), strain A24 were analyzed as candidate T‐cell epitopes. Peptides predicted by the NetMHCpan were tested in ELISA for binding to the SLA‐1*0401 and SLA‐2*0401 major histocompatibility complex class I proteins. Four of the 10 predicted...

  8. Molecular basis of a unique tumor antigen of radiation leukemia virus-induced leukemia B6RV2: its relation to MuLV gp70 of xenotropic class

    Hybridomas secreting monoclonal antibodies that reacted with the B6 radiation leukemia virus (RadLV)-induced leukemia B6RV2 were produced by fusion of BALB/c NS-1 myeloma cells with spleen cells from (BALB/c X B6)F1 mice immunized with B6RV2. By direct and absorption analyses with 28 B6 and BALB/c leukemias, the monoclonal antibodies NU7-4 and NU7-99 were shown to react only with B6RV2, indicating that they recognized an individually distinct antigen on B6RV2 that was identified previously with conventional (BALB/c X B6)F1 anti-B6RV2 serum. Another monoclonal antibody, NU1-132, showed relatively restricted reactivity with B6 RadLV leukemias. These three monoclonal antibodies all precipitated material of approximately 80,000 daltons, which is the same size as that precipitated by anti-xenotropic MuLV gp70 serum. Sequential immunoprecipitation analysis revealed that the molecules precipitated by NU7-4 were not removed by pretreatment of NU7-99 or NU1-132 and that the molecules precipitated by NU7-99 were not removed by NU7-4 or NU1-132. The molecules precipitated by NU1-132 were partially removed by pretreatment with NU7-4, but not with NU7-99. The molecules precipitated by these three monoclonal antibodies were removed by pretreatment with anti-xenotropic gp70. These results suggested heterogeneity of the xenotropic MuLV gp70-related molecules expressed on B6RV2 and a possible relation between serologically defined unique tumor antigens and gp70-related molecules

  9. Association of Helicobacter pylori with HLA-DR antigen expression in gastritis.

    Wee, A; Teh, M; Kang, J Y


    AIMS: To assess the association between Helicobacter pylori-associated gastritis and HLA-DR antigen (class II antigen) expression. METHODS: Fifty endoscopic gastric biopsy specimens were studied for the presence of H pylori, degree and type of inflammation, and for HLA-DR antigen expression in the epithelium. The cases were chosen to represent different categories: inflamed gastric mucosa with (n = 13) and without (n = 20) H pylori, and non-inflamed mucosa (n = 17). RESULTS: The antigen was a...

  10. Facts on the fragmentation of antigens in presenting cells, on the association of antigen fragments with MHC molecules in cell-free systems, and speculation on the cell biology of antigen processing

    Werdelin, O; Mouritsen, S; Petersen, B L;


    The processing of a protein antigen is a multi-step event taking place in antigen-presenting cells. Processing is a prerequisite for the recognition of most antigens by T lymphocytes. The antigen is ingested by endocytosis, transported to an acid cellular compartment and subjected to proteolytic...... fragmentation. Some of the antigen fragments bind to MHC class II molecules and are transported to the surface of the antigen-presenting cell where the actual presentation to T lymphocytes occurs. The nature of the processed antigen, how and where it is derived and subsequently becomes associated with MHC...... molecules are the questions discussed in this review. To us, the entire concept of processing has appeal not only because it explains some hitherto well-established, but poorly understood, phenomena such as the fact that T lymphocytes focus their attention entirely upon antigens on other cells. It has...

  11. No Major Role for Insulin-Degrading Enzyme in Antigen Presentation by MHC Molecules

    Culina, Slobodan; Mauvais, François-Xavier; Hsu, Hsiang-Ting; Burgevin, Anne; Guénette, Suzanne; Moser, Anna; van Endert, Peter


    Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE) was shown to produce an antigenic peptide derived from the tumor antigen MAGE-...

  12. Idiopathic focal segmental glomerulosclerosis and HLA antigens

    M. Gerbase-DeLima


    Full Text Available The objective of the present study was to investigate a possible association between HLA class II antigens and idiopathic focal segmental glomerulosclerosis (FSGS. HLA-A, -B, -DR and -DQ antigens were determined in 19 Brazilian patients (16 white subjects and three subjects of Japanese origin with biopsy-proven FSGS. Comparison of the HLA antigen frequencies between white patients and white local controls showed a significant increase in HLA-DR4 frequency among FSGS patients (37.7 vs 17.2%, P<0.05. In addition, the three patients of Japanese extraction, not included in the statistical analysis, also presented HLA-DR4. In conclusion, our data confirm the association of FSGS with HLA-DR4 previously reported by others, thus providing further evidence for a role of genes of the HLA complex in the susceptibility to this disease

  13. The two neutrophil plasma membrane markers alkaline phosphatase and HLA class I antigen localize differently in granule-deficient cytoplasts. An ideal plasma membrane marker in human neutrophils is still lacking.

    Pellmé, Sara; Dahlgren, Claes; Karlsson, Anna


    Neutrophil function relies largely on the ability of the cell to mobilize its different granules and vesicles to the cell surface and thereby expose and/or release effector molecules to the surrounding tissue. To properly identify these subcellular compartments is thus a prerequisite for studies of neutrophil physiology. A range of specific markers for the classical granules is available, but finding optimal markers for the secretory vesicles and plasma membrane has historically been more challenging. Latent and non-latent alkaline phosphatase activities are often used to distinguish these two light membrane structures, but the outcome using this technique depends on the level of cellular activation. Therefore, HLA-I was introduced some years ago as a specific, stimulation-independent marker for the plasma membrane. In this study we however report that detailed fractionation studies of neutrophil cytoplasts, lacking secretory vesicles, granules and other dense organelles, reveal that the HLA-I antigen is not only co-localizing with the plasma membrane marker ALP, but is also present in other, more dense organelles. Further, we found the mixed enzyme-linked immunosorbent assay (MELISA), detecting the beta(2)-microglobulin/HLA-I complex, to be negatively influenced by uncomplexed beta(2)-microglobulin present in the specific granules and secretory vesicles, making it difficult to use HLA-I as a plasma membrane marker during maturation of for example phagolysosomes. PMID:17673253

  14. Identification of peptides from foot‐and‐mouth disease virus structural proteins bound by class I swine leukocyte antigen (SLA) alleles, SLA‐1*0401 and SLA‐2*0401

    Pedersen, Lasse Eggers; Harndahl, M.; Nielsen, Morten;


    within the structural proteins of foot‐and‐mouth disease virus (FMDV), strain A24 were analyzed as candidate T‐cell epitopes. Peptides predicted by the NetMHCpan were tested in ELISA for binding to the SLA‐1*0401 and SLA‐2*0401 major histocompatibility complex class I proteins. Four of the 10 predicted...... FMDV peptides bound to SLA‐2*0401, whereas five of the nine predicted FMDV peptides bound to SLA‐1*0401. These methods provide the characterization of T‐cell epitopes in response to pathogens in more detail. The development of such approaches to analyze vaccine performance will contribute to a more...

  15. Photoaffinity labeling demonstrates binding between Ia and antigen on antigen-presenting cells

    Antigen-presenting cells (APCs) bind and present antigens to immunocompetent T lymphocytes in the context of Ia molecules: however, the molecular nature of the immunogenic complexes on the surface of these cells is unknown. They have used radioiodinated photoreactive Beef insulin (BI) derivatized in the B29 position with (n-[4-(4'-azido-3'-[125]iodophenylazo)benzoyl]-3-aminopropyl-n-oxy-succinimide) (B29-AZAP) as antigen to examine the nature of these molecular complexes. The probe was reacted with either of two B hybridoma APCs, TA3 (Ia/sup k/d/) and LB(Ia/sup d/b/) which present insulin on I-A/sup d/ and I-A/sub b/ respectively, to appropriately restricted, BI specific T helper lymphocytes (T/sub H/). Samples were photolyzed, solubilized and then analyzed by SDS-PAGE. Two protein bands of 36-kDa and 27-kDa were specifically labeled on TA3 and LB cells. Treatment of these bands with dithiothreitol or endo-N-β-glycosidase F demonstrates that each is composed of a single glycoprotein. These bands are immunoprecipitable with haplotype specific but not control anti-Ia antibodies. This identifies the labeled bands as the α- and β- subunits of class II MHC antigens. They conclude that a molecular complex may form between Ia and antigen on APCs and that formation of this complex does not require the presence of an antigen specific T/sub H/ cell receptor

  16. Sibling rivalry: competition between MHC class II family members inhibits immunity.

    Denzin, Lisa K; Cresswell, Peter


    Peptide loading of major histocompatibility complex (MHC) class II molecules in the endosomes and lysosomes of antigen-presenting cells is catalyzed by human leukocyte antigen-DM (HLA-DM) and modulated by HLA-DO. In a structural study in this issue, Guce et al. show that HLA-DO is an MHC class II mimic and functions as a competitive and essentially irreversible inhibitor of HLA-DM activity, thereby inhibiting MHC class II antigen presentation. PMID:23288359

  17. Autophagy proteins stabilize pathogen-containing phagosomes for prolonged MHC II antigen processing.

    Romao, Susana; Gasser, Nathalie; Becker, Andrea C; Guhl, Bruno; Bajagic, Milica; Vanoaica, Danusia; Ziegler, Urs; Roesler, Joachim; Dengjel, Jörn; Reichenbach, Janine; Münz, Christian


    Antigen preservation for presentation is a hallmark of potent antigen-presenting cells. In this paper, we report that in human macrophages and dendritic cells, a subset of phagosomes gets coated with Atg8/LC3, a component of the molecular machinery of macroautophagy, and maintains phagocytosed antigens for prolonged presentation on major histocompatibility complex class II molecules. These Atg8/LC3-positive phagosomes are formed around the antigen with TLR2 agonists and require reactive oxygen species production by NOX2 for their generation. A deficiency in the NOX2-dependent formation of these antigen storage phagosomes could contribute to compromise antifungal immune control in chronic granulomatous disease patients. PMID:24322427

  18. Boosting the MHC class II-restricted tumor antigen presentation to CD4+ T helper cells: a critical issue for triggering protective immunity and re-orienting the tumor microenvironment toward an anti-tumor state



    Full Text Available Although the existence of an immune response against tumor cells is well documented, the fact that tumors take off in cancer patients indicates that neoplastic cells can circumvent this response. Over the years many investigators have described strategies to rescue the anti-tumor immune response with the aim of creating specific and long lasting protection against the disease. When exported to human clinical settings, these strategies have revealed in most cases a very limited, if any, positive outcome.We believe that the failure is mostly due to the inadequate triggering of the CD4+ T helper cell (TH arm of the adaptive immunity, as TH cells are necessary to trigger all the immune effector mechanisms required to eliminate tumor cells. In this review we focus on novel strategies that by stimulating MHC class II-restricted activation of TH cells generate a specific and persistent adaptive immunity against the tumor.This point is of critical importance for both preventive or therapeutic anti-tumor vaccination protocols, because adaptive immunity with its capacity to produce specific, long lasting protection and memory responses, is indeed the final goal of vaccination. We will discuss data from our as well as other laboratories which strongly suggest that triggering a specific and persistent anti-tumor CD4+ TH cell response stably modify not only the tumor microenvironment but also tumor-dependent extratumor microenvironments eliminating and/or reducing the blood-derived tumor infiltrating cells that may have a pro-tumor growth function such as regulatory CD4+/CD25+ T cells (Tregs and myeloid-derived suppressor cells (MDSC. Within this frame therefore, we believe that the establishment of a pro-tumor environment is not the cause but simply the consequence of the tumor strategy to primarily counteract components of the adaptive cellular immunity, particularly TH lymphocytes.

  19. Cancer vaccine--Antigenics.


    Antigenics is developing a therapeutic cancer vaccine based on heat-shock proteins (HSPs). The vaccine [HSPPC-96, Oncophage] is in a pivotal phase III clinical trial for renal cancer at 80 clinical sites worldwide. The trial is enrolling at least 500 patients who are randomised to receive surgical removal of the primary tumour followed by out-patient treatment with Oncophage((R)) or surgery only. This study was initiated on the basis of results from a pilot phase I/II study and preliminary results from a phase II study in patients with renal cell cancer. In October 2001, Oncophage was designated as a fast-track product by the Food and Drug Administration in the US for the treatment of renal cell carcinoma. Oncophage is in phase I/II trials in Italy for colorectal cancer (30 patients) and melanoma. The trials in Italy are being conducted at the Istituto dei Tumouri, Milan (in association with Sigma-Tau). Preliminary data from the phase II trial for melanoma was presented at the AACR-NCI-EORTC International Conference in Florida, USA, in October 2001. Oncophage is also in a phase I/II (42 patients) and a phase II trial (84 patients) in the US for renal cell cancer, a phase II trial in the US for non-Hodgkin's lymphoma (35 patients), a phase II trial in the US for sarcoma (20-35 patients), a phase I/II trial in the US for melanoma (36 patients), and phase I/II trials in Germany for gastric (30 patients) and pancreatic cancers. A pilot phase I trial in patients with pancreatic cancer began in the US in 1997 with 5 patients enrolled. In November 2000, Antigenics announced that this trial had been expanded to a phase I/II study which would now include survival as an endpoint and would enroll 5 additional patients. The US trials are being performed at Memorial Sloan-Kettering Cancer Center and the M.D. Anderson Cancer Center. The trials in Germany are being carried out at Johannes Gutenberg-University Hospital, Mainz. Oncophage is an autologous vaccine consisting of

  20. Antigen smuggling in tuberculosis.

    Hudrisier, Denis; Neyrolles, Olivier


    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

  1. Antigen detection systems

    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...

  2. Aspergillus antigen skin test (image)

    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 ...

  3. Classification of human leukocyte antigen (HLA) supertypes

    Wang, Mingjun; Claesson, Mogens H


    Identification of new antigenic peptides, derived from infectious agents or cancer cells, which bind to human leukocyte antigen (HLA) class I and II molecules, is of importance for the development of new effective vaccines capable of activating the cellular arm of the immune response. However, the...... barrier to the development of peptide-based vaccines with maximum population coverage is that the restricting HLA genes are extremely polymorphic resulting in a vast diversity of peptide-binding HLA specificities and a low population coverage for any given peptide-HLA specificity. One way to reduce this...... complexity is to group thousands of different HLA molecules into several so-called HLA supertypes: a classification that refers to a group of HLA alleles with largely overlapping peptide binding specificities. In this chapter, we focus on the state-of-the-art classification of HLA supertypes including HLA...

  4. Probing the S1 specificity pocket of the aminopeptidases that generate antigenic peptides

    Zervoudi, Efthalia; Papakyriakou, Athanasios; Georgiadou, Dimitra; Evnouchidou, Irini; Gajda, Anna; Poreba, Marcin; Salvesen, Guy S.; Drag, Marcin; Hattori, Akira; Swevers, Luc; Vourloumis, Dionisios; Stratikos, Efstratios


    Abstract ER aminopeptidase 1 (ERAP1), ER aminopeptidase 2 (ERAP2) and Insulin Regulated aminopeptidase (IRAP) are three homologous enzymes that play critical roles in the generation of antigenic peptides. These aminopeptidases excise amino acids from N-terminally extended precursors of antigenic peptides in order to generate the correct length epitopes for binding onto MHC class I molecules. The specificity of these peptidases can affect antigenic peptide selection, but has not yet...

  5. Interferon-gamma-like molecule induces Ia antigens on cultured mast cell progenitors.

    Wong, G H; Clark-lewis, I.; McKimm-Breschkin, J L; Schrader, J W


    Persisting (P) cells (murine cells that resemble mast cells and grow continuously in vitro for prolonged periods in the presence of a specific growth factor) did not express detectable levels of Ia antigens (murine class II major histocompatibility antigens) when their growth was supported by partially purified P cell-stimulating factor. However, when these Ia-negative P cells were transferred to medium conditioned by concanavalin A-stimulated spleen cells, Ia antigens appeared within 24 hr. ...

  6. Circulating human basophils lack the features of professional antigen presenting cells

    Sharma, Meenu; Hegde, Pushpa; Aimanianda, Vishukumar; Beau, Remi; Sénéchal, Helene; Poncet, Pascal; Latgé, Jean-Paul; Kaveri, Srini V; Bayry, Jagadeesh


    Recent reports in mice demonstrate that basophils function as antigen presenting cells (APC). They express MHC class II and co-stimulatory molecules CD80 and CD86, capture and present soluble antigens or IgE-antigen complexes and polarize Th2 responses. Therefore, we explored whether human circulating basophils possess the features of professional APC. We found that unlike dendritic cells (DC) and monocytes, steady-state circulating human basophils did not express HLA-DR and co-stimulatory mo...

  7. Immune response to immunodominant Mycobacterium tuberculosis antigen ESAT-6 derived peptide is HLA-haplotype dependent

    Smart, Michele; Behrens, Marshall; David, Luckey; Conway, Catherine; Taneja, Veena


    The antigenic proteins of Mycobacterium tuberculosis (Mtb) have been defined. We used synthetic peptides of secreted antigens, early secreted antigenic target 6 (ESAT-6) and cultural filtrate protein-10 (CFP-10), of Mtb and characterized the immune response in context of HLA genes. Humanized mice lacking endogenous class II molecules but expressing various human DR and DQ HLA transgenes singly or as a haplotype were used to study the HLA-mediated immune response to peptides. Our observations ...

  8. Stool Test: H. Pylori Antigen

    ... All About Food Allergies Stool Test: H. Pylori Antigen KidsHealth > For Parents > Stool Test: H. Pylori Antigen Print A A A Text Size What's in ... sample is used to determine if H. pylori antigens are present in your child's gastrointestinal (GI) system. ...

  9. Antigen Discovery: a Postgenomic Approach to Leprosy Diagnosis

    Aráoz, Romulo; Honoré, Nadine; Cho, Sungae; Kim, Jong-Pill; Cho, Sang-Nae; Monot, Marc; Demangel, Caroline; Brennan, Patrick J.; Cole, Stewart T.


    Leprosy is an infectious, neurodegenerative disease of humans caused by Mycobacterium leprae. Despite effective control programs, the incidence of leprosy remains stubbornly high, suggesting that transmission may be more common than expected. The rationale of this work was to use bioinformatics and comparative genomics to identify potentially antigenic proteins for diagnostic purposes. This approach defined three classes of proteins: those restricted to M. leprae (class I), those present in M...

  10. Brain antigens: components of subfractions from human grey matter

    Rajam, P. C.; Bogoch, S.


    1. Using chromatography on DEAE-cellulose, a neutral, low ionic strength extract of human grey matter has been separated into fractions of proteins with basic and progressively acidic groups. 2. The reactions of each group with rabbit antiserum against the original extract, in double-diffusion tests, suggest the presence of a minimum total of thirteen distinct antigens between them. These results are supported by immunoelectrophoretic findings, which indicate the basic group to contain five, and the progressively acidic group seven to eight distinct antigens. These antigens do not appear to be human serum proteins. 3. Antigens belonging to the BE class (resistant to boiling and relatively soluble in ethanol) are present among the progressively acidic proteins, and possibly among the basic proteins also. ImagesFIG. 2 PMID:4958737

  11. Class size versus class composition

    Jones, Sam

    Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...

  12. Immunoassay of antigens

    A method is described of immunoassay of an antigen in a liquid sample wherein a complex is formed between antigen contained in the said sample and two or more antibody reagents, and the said complex is bound to a solid support by non-covalent bonding as defined herein: and the amount of complex becoming bound to the support is determined; the process employing at least one monoclonal antibody reagent. Labelling methods including radioactive, fluorimetric and enzyme labelling may be used to effect determination of the binding ofthe complex to the solid support. The solid support may take the form of particles, beads, wall-coatings on the reaction vessel or an insert of large surface area. The method is particularly applicable to the assay of TSH, CEA, HCG, alphafeto protein, immunoglobulins, viruses, allergens, bacteria, toxins, drugs and vitamins. Use of monoclonal reagents improves the specificity of the process, and also decreases non-specific binding

  13. Autologous peptides constitutively occupy the antigen binding site on Ia

    Buus, S; Sette, A; Colon, S M;


    Low molecular weight material associated with affinity-purified class II major histocompatibility complex (MHC) molecules of mouse (Ia) had the expected properties of peptides bound to the antigen binding site of Ia. Thus, the low molecular weight material derived from the I-Ad isotype was...

  14. Word classes

    Rijkhoff, Jan


    This article provides an overview of recent literature and research on word classes, focusing in particular on typological approaches to word classification. The cross-linguistic classification of word class systems (or parts-of-speech systems) presented in this article is based on statements found...... in grammatical descriptions of some 50 languages, which together constitute a representative sample of the world’s languages (Hengeveld et al. 2004: 529). It appears that there are both quantitative and qualitative differences between word class systems of individual languages. Whereas some languages...... employ a parts-of-speech system that includes the categories Verb, Noun, Adjective and Adverb, other languages may use only a subset of these four lexical categories. Furthermore, quite a few languages have a major word class whose members cannot be classified in terms of the categories Verb – Noun...

  15. Enhancing the recognition of tumor associated antigens

    Restifo, Nicholas P; Irvine, Kari R.; Minev, Boris R.; Taggarse, Akash S.; McFariand, Barbra J.; Wang, Michael


    Activated CD8+ T cells (TCD8+) can directly recognize malignant cells because processed fragments of tumor associated antigens (TAA), 8-10 amino acids in length and complexed with MHC class I molecules, are displayed on tumor cell surfaces. Tumor cells have been genetically modified in a variety of ways in efforts to enhance the immune recognition of TAA. An alternative strategy is the expression of TAA in recombinant or synthetic form. This has been made possible by the recent cloning of TAA...

  16. Low dose antigen promotes induction of FOXP3 in human CD4+ T cells

    Long, S. Alice; Rieck, Mary; Tatum, Megan; Bollyky, Paul L.; Wu, Rebecca P.; Muller, Isabelle; Ho, Jhon-Chun; Shilling, Heather G.; Buckner, Jane H.


    Low antigen dose promotes induction and persistence of Treg in mice, yet few studies have addressed the role of antigen dose in the induction of adaptive CD4+FOXP3+ Treg in humans. To this end, we examined the level of FOXP3 expression in human CD4+CD25− T cells upon activation with autologous antigen presenting cells and varying doses of peptide. Antigen specific T cells expressing FOXP3 were identified by flow cytometry using MHC Class II tetramer (Tmr). We found an inverse relationship bet...

  17. Carcino-Embryonic Antigen

    Tumour marker analysis has increased our understanding of the presence of tumours in the body. Carcino-embryonic antigen, CEA, is one of the best studied tumour markers and has proved an ideal diagnostic adjuvant. It has helped in quantifying the amount of disease present in a patient and thence to make accurate prognosis on the various diagnosed ailments. At UCH, it is observed that there is an increase in cancer related ailments and therefore the need for early diagnosis is more compelling in our environment to mitigate future cost of managing advanced manifestation

  18. Cloning of NruI and Sbo13I restriction and modification sstems in E. coli and amino acid sequence comparison of M.NruI and M.Sbo13I with other amino-methyltransferases

    Benner Jack


    Full Text Available Abstract Background NruI and Sbo13I are restriction enzyme isoschizomers with the same recognition sequence 5' TCG↓CGA 3' (cleavage as indicated↓. Here we report the cloning of NruI and Sbo13I restriction-modification (R-M systems in E. coli. The NruI restriction endonuclease gene (nruIR was cloned by PCR and inverse PCR using primers designed from the N-terminal amino acid sequence. The NruI methylase gene (nruIM was derived by inverse PCR walking. Results The amino acid sequences of NruI endonuclease and methylase are very similar to the Sbo13I R-M system which has been cloned and expressed in E. coli by phage selection of a plasmid DNA library. Dot blot analysis using rabbit polyclonal antibodies to N6mA- or N4mC-modified DNA indicated that M.NruI is possibly a N6mA-type amino-methyltransferase that most likely modifies the external A in the 5' TCGCGA 3' sequence. M.Sbo13I, however, is implicated as a probable N4mC-type methylase since plasmid carrying sbo13IM gene is not restricted by Mrr endonuclease and Sbo13I digestion is not blocked by Dam methylation of the overlapping site. The amino acid sequence of M.NruI and M.Sbo13I did not show significant sequence similarity to many known amino-methyltransferases in the α, β, and γ groups, except to a few putative methylases in sequenced microbial genomes. Conclusions The order of the conserved amino acid motifs (blocks in M.NruI/M.Sbo13I is similar to the γ. group amino-methyltranferases, but with two distinct features: In motif IV, the sequence is DPPY instead of NPPY; there are two additional conserved motifs, IVa and Xa as extension of motifs IV and X, in this family of enzymes. We propose that M.NruI and M.Sbo13I form a subgroup in the γ group of amino-methyltransferases.

  19. Human leucocyte antigens in tympanosclerosis.

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


    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

  20. Antigenic variants of rabies virus

    Wiktor, TJ; Koprowski, H


    Antigenic variants of CVS-11 strain of rabies virus were selected after treatment of virus populations with monoclonal antibodies directed against the glycoprotein antigen of the virus. These variants resisted neutralization by the hybridoma antibody used for their selection. Two independently mutating antigenic sites could be distinguished when five variants were tested with nine hybridoma antibodies. The frequency of single epitope variants in a cloned rabies virus seed was approximately 1:...

  1. Lipid peroxidation causes endosomal antigen release for cross-presentation.

    Dingjan, Ilse; Verboogen, Daniëlle Rj; Paardekooper, Laurent M; Revelo, Natalia H; Sittig, Simone P; Visser, Linda J; Mollard, Gabriele Fischer von; Henriet, Stefanie Sv; Figdor, Carl G; Ter Beest, Martin; van den Bogaart, Geert


    Dendritic cells (DCs) present foreign antigen in major histocompatibility complex (MHC) class I molecules to cytotoxic T cells in a process called cross-presentation. An important step in this process is the release of antigen from the lumen of endosomes into the cytosol, but the mechanism of this step is still unclear. In this study, we show that reactive oxygen species (ROS) produced by the NADPH-oxidase complex NOX2 cause lipid peroxidation, a membrane disrupting chain-reaction, which in turn results in antigen leakage from endosomes. Antigen leakage and cross-presentation were inhibited by blocking ROS production or scavenging radicals and induced when using a ROS-generating photosensitizer. Endosomal antigen release was impaired in DCs from chronic granulomatous disease (CGD) patients with dysfunctional NOX2. Thus, NOX2 induces antigen release from endosomes for cross-presentation by direct oxidation of endosomal lipids. This constitutes a new cellular function for ROS in regulating immune responses against pathogens and cancer. PMID:26907999

  2. Novel vaccine strategies to T-independent antigens.

    Lesinski, G B; Westerink, M A


    T cell independent antigens do not require T cell help to induce an immune response, and are characterized by a lack of immunologic memory. These antigens can be divided into two classes, TI-1 or TI-2. TI-1 antigens, such as bacterial lipopolysaccharide, are potent B-cell mitogens, capable of non-specific, polyclonal activation of B cells. In contrast, TI-2 antigens can only activate mature B cells and consist of highly repetitive structures, such as capsular polysaccharides (CPS) from bacteria. Many vaccines currently in use consist of purified capsular polysaccharides from pathogenic bacteria such as Streptococcus pneumoniae and Neisseria meningitidis. These vaccines are efficacious in immune-competent adults, however, due to their TI-2 nature, are not effective in children <2 years of age. Converting polysaccharides into T cell dependent (TD) antigens, allows children, <2, to produce an effective immune response. This review focuses on various strategies used to convert the immune response to polysaccharide antigens from TI-2 to a TD response. Conjugate vaccines, anti-idiotypic antibodies, phage display library technology and DNA vaccines are discussed. PMID:11576678

  3. Regulation of antigen presentation by acidic pH


    The effect of pH on functional association of peptide antigens with APC membranes was investigated by using aldehyde-fixed B cells and class II- restricted T cell hybridomas to assess antigen/MHC complex formation. The results indicated that the rate and extent of functional peptide binding was markedly increased at pH 5.0 as compared with pH 7.3. The pH dependence of binding was preserved after pretreatment of fixed APC with pH 5.0 buffer, suggesting that pH had a direct effect on the intera...

  4. 9 CFR 113.407 - Pullorum antigen.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Pullorum antigen. 113.407 Section 113... and Reagents § 113.407 Pullorum antigen. Pullorum Antigen shall be produced from a culture of... standard for stained antigen K's and 50 ±10 times McFarland No. 1 standard for tube antigen....

  5. Liposomes Containing Lipid A Serve as an Adjuvant for Induction of Antibody and Cytotoxic T-Cell Responses against RTS,S Malaria Antigen

    Richards, Roberta L.; Rao, Mangala; Wassef, Nabila M.; Glenn, Gregory M.; Rothwell, Stephen W.; Alving, Carl R.


    Encapsulation of soluble protein antigens in liposomes was previously shown to result in processing of antigen via the major histocompatibility complex class I pathway, as evidenced by costaining of the trans-Golgi region of murine bone marrow-derived macrophages (BMs) by fluorophore-labeled liposomal antigen and by a trans-Golgi-specific fluorescent lipid. Evidence is presented here that free or liposome-encapsulated RTS,S, a particulate malaria antigen consisting of hepatitis B particles co...

  6. Antigen antibody interactions

    DeLisi, Charles


    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  7. Trypanosoma cruzi: circulating antigens

    V. Bongertz


    Full Text Available Circulating antigens were detected in sera of mice experimentally infected with a high close of Trypanosoma cruzi by reaction with sera from chronically infected mice. The immunodiffusion reaction between homologous acute and chronic sera produced four precipitation lines. By reaction with chronic mouse serum, circulating antingens were detected in sera from heavily infected hamsters, dogs, rabbits and in sera from chagasic patients. A reaction was also found in urine from acutely infected mice and dogs. Trypanosoma cruzi exoantigen was detected in trypanosome culture medium and in the supernatant of infected cell cultures. Attempts to isolate the antigens are described.Antígenos circulantes foram detectados em soros de camundongos infectados experimentalmente com elevadas doses de Trypanosoma cruzi pela reação com soros obtidos de camundongos em fase crônica de infecção. A reação de imunodifusão entre soros homólogos agudo e crônico produziu quatro linhas de precipitação. Por reação com soro crônico de camundongo antígenos circulantes foram detectados em soros de crícetos, cães e coelhos infectados com doses elevadas de Trypanosoma cruzi e em soros de pacientes chagásicos. Uma reação foi também observada com urina de camundongos e cães infectados de forma aguda. Exoantígeno de Trypanosoma cruzi foi detectado em meio de cultura de tripanosomas e em sobrenadantes de culturas de células infectadas. Tentativas de isolamento dos antigenos são descritas.

  8. Cancer antigen 125 and prognosis

    Høgdall, Estrid Vilma Solyom


    PURPOSE OF REVIEW: This review addresses recently reported progress in cancer antigen 125 as a prognostic marker in patients with ovarian cancer. RECENT FINDINGS: Serum cancer antigen 125 levels measured preoperatively in both early and late stage ovarian cancer may be of prognostic value. Before...... cancer antigen 125 determination may be implemented into clinical practice, cut-off levels must be evaluated and internationally defined. Studies examining serum cancer antigen 125 levels after surgery but before, during, or after treatment confirmed that changes in serum levels are of prognostic value....... Furthermore, recent studies have shown that the level of expression of cancer antigen 125 in tissue may be an independent prognostic indicator in late stage ovarian cancer. SUMMARY: Prognostic markers may potentially help to individualize treatment within subgroups of patients. In a recent study the level of...

  9. No major role for insulin-degrading enzyme in antigen presentation by MHC molecules.

    Slobodan Culina

    Full Text Available Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE was shown to produce an antigenic peptide derived from the tumor antigen MAGE-A3 in an entirely proteasome-independent manner, raising the question of the global impact of IDE in MHC class I antigen processing. Here we report that IDE knockdown in human cell lines, or knockout in two different mouse strains, has no effect on cell surface expression of various MHC class I molecules, including allomorphs such as HLA-A3 and HLA-B27 suggested to be loaded in an at least a partly proteasome-independent manner. Moreover, reduced or absent IDE expression does not affect presentation of five epitopes including epitopes derived from beta amyloid and proinsulin, two preferred IDE substrates. Thus, IDE does not play a major role in MHC class I antigen processing, confirming the dominant and almost exclusive role of the proteasome in cytosolic production of MHC class I ligands.

  10. No major role for insulin-degrading enzyme in antigen presentation by MHC molecules.

    Culina, Slobodan; Mauvais, François-Xavier; Hsu, Hsiang-Ting; Burgevin, Anne; Guénette, Suzanne; Moser, Anna; van Endert, Peter


    Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE) was shown to produce an antigenic peptide derived from the tumor antigen MAGE-A3 in an entirely proteasome-independent manner, raising the question of the global impact of IDE in MHC class I antigen processing. Here we report that IDE knockdown in human cell lines, or knockout in two different mouse strains, has no effect on cell surface expression of various MHC class I molecules, including allomorphs such as HLA-A3 and HLA-B27 suggested to be loaded in an at least a partly proteasome-independent manner. Moreover, reduced or absent IDE expression does not affect presentation of five epitopes including epitopes derived from beta amyloid and proinsulin, two preferred IDE substrates. Thus, IDE does not play a major role in MHC class I antigen processing, confirming the dominant and almost exclusive role of the proteasome in cytosolic production of MHC class I ligands. PMID:24516642

  11. Oxidative stress can alter the antigenicity of immunodominant peptides

    Weiskopf, Daniela; Schwanninger, Angelika; Weinberger, Birgit; Almanzar, Giovanni; Parson, Walther; Buus, Søren; Lindner, Herbert; Grubeck-Loebenstein, Beatrix


    APCs operate frequently under oxidative stress induced by aging, tissue damage, pathogens, or inflammatory responses. Phagocytic cells produce peroxides and free-radical species that facilitate pathogen clearance and can in the case of APCs, also lead to oxidative modifications of antigenic...... proteins and peptides. Little information is available presently about the consequences of such modifications on the immune response. To model oxidative modification of an immunodominant antigenic peptide, we oxidized the methionine residue of the human CMV pp65(495-503) (NLVPMVATV) peptide. Such...... modifications of an antigenic peptide can affect MHC binding or TCR recognition. Using binding and dissociation assays, we demonstrate that oxidative modification of the CMVpp65(495-503) peptide leads to a decreased binding of the pMHC complex to the TCR, whereas binding of the peptide to the MHC class I...

  12. Rapid assessment of the antigenic integrity of tetrameric HLA complexes by human monoclonal HLA antibodies.

    Eijsink, Chantal; Kester, Michel G D; Franke, Marry E I; Franken, Kees L M C; Heemskerk, Mirjam H M; Claas, Frans H J; Mulder, Arend


    The ability of tetrameric major histocompatibility complex (MHC) class I-peptide complexes (tetramers) to detect antigen-specific T lymphocyte responses has yielded significant information about the generation of in vivo immunity in numerous antigenic systems. Here we present a novel method for rapid validation of tetrameric HLA molecules based on the presence of allodeterminants. Human monoclonal antibodies (mAbs) recognizing polymorphic determinants on HLA class I were immobilized on polystyrene microparticles and used to probe the structural integrity of tetrameric HLA class I molecules by flow cytometry. A total of 22 tetramers, based on HLA-A1, A2, A3, A24, B7 and B8 were reactive with their counterpart mAbs, thus confirming their antigenic integrity. A positive outcome of this mAb test ensures that tetrameric HLA class I can be used with greater confidence in subsequent functional assays. PMID:16973172

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

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


    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

  14. Class distinction

    White, M. Catherine

    Typical 101 courses discourage many students from pursuing higher level science and math courses. Introductory classes in science and math serve largely as a filter, screening out all but the most promising students, and leaving the majority of college graduates—including most prospective teachers—with little understanding of how science works, according to a study conducted for the National Science Foundation. Because few teachers, particularly at the elementary level, experience any collegiate science teaching that stresses skills of inquiry and investigation, they simply never learn to use those methods in their teaching, the report states.


    Rita G SOUSA


    Full Text Available Context Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety. In literature, there is reference to transient carcinoembryonic antigen increase with colonoscopy. Objective To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. Methods We prospectively studied subjects that underwent routine colonoscopy in our institution. Blood samples were collected (1 before bowel cleaning, (2 before colonoscopy and (3 immediately after colonoscopy. Blood carcinoembryonic antigen levels were determined by “Sandwich” immunoassay. The statistical methods used were the paired t-test and ANOVA. Results Thirty-seven patients (22M/15F were included; age range 28-84 (mean 56 years. Mean carcinoembryonic antigen values were 1.9, 2 and 1.8 for (1, (2 and (3, respectively. An increase in value (2 compared with (1 was observed in 20/37 patients (P = 0.018, mainly in younger patients and in patients requiring more endoluminal interventions. In 29/37 patients, the CEA value decreased from (2 to (3 (P = 1.3x10-7. Conclusions A trend for carcinoembryonic antigen increase after bowel cleaning was observed, especially in younger patients and in patients with more endoluminal interventions, but without clinical meaning.

  16. Rationally designed inhibitor targeting antigen-trimming aminopeptidases enhances antigen presentation and cytotoxic T-cell responses.

    Zervoudi, Efthalia; Saridakis, Emmanuel; Birtley, James R; Seregin, Sergey S; Reeves, Emma; Kokkala, Paraskevi; Aldhamen, Yasser A; Amalfitano, Andrea; Mavridis, Irene M; James, Edward; Georgiadis, Dimitris; Stratikos, Efstratios


    Intracellular aminopeptidases endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2), and as well as insulin-regulated aminopeptidase (IRAP) process antigenic epitope precursors for loading onto MHC class I molecules and regulate the adaptive immune response. Their activity greatly affects the antigenic peptide repertoire presented to cytotoxic T lymphocytes and as a result can regulate cytotoxic cellular responses contributing to autoimmunity or immune evasion by viruses and cancer cells. Therefore, pharmacological regulation of their activity is a promising avenue for modulating the adaptive immune response with possible applications in controlling autoimmunity, in boosting immune responses to pathogens, and in cancer immunotherapy. In this study we exploited recent structural and biochemical analysis of ERAP1 and ERAP2 to design and develop phosphinic pseudopeptide transition state analogs that can inhibit this family of enzymes with nM affinity. X-ray crystallographic analysis of one such inhibitor in complex with ERAP2 validated our design, revealing a canonical mode of binding in the active site of the enzyme, and highlighted the importance of the S2' pocket for achieving inhibitor potency. Antigen processing and presentation assays in HeLa and murine colon carcinoma (CT26) cells showed that these inhibitors induce increased cell-surface antigen presentation of transfected and endogenous antigens and enhance cytotoxic T-cell responses, indicating that these enzymes primarily destroy epitopes in those systems. This class of inhibitors constitutes a promising tool for controlling the cellular adaptive immune response in humans by modulating the antigen processing and presentation pathway. PMID:24248368

  17. Detection of Histoplasma capsulatum Antigen in Panamanian Patients with Disseminated Histoplasmosis and AIDS▿

    Gutierrez, Maria Eugenia; Canton, Alfredo; Connolly, Patricia; Zarnowski, Robert; Wheat, L. Joseph


    Histoplasmosis is a common endemic mycosis in the Americas, often causing severe disease in patients with AIDS. Antigen detection has become an important method for rapid diagnosis of histoplasmosis in the United States but not in Central or South America. Isolates from patients in the United States are predominantly found to be class 2 isolates when typed using the nuclear gene YPS3, while isolates from Latin America are predominantly typed as class 5 or class 6. Whether infection with these...

  18. The role of FcRn in antigen presentation

    Kristi eBaker


    Full Text Available Immunoglobulins are unique molecules capable of simultaneously recognizing a diverse array of antigens and themselves being recognized by a broad array of receptors. The abundance specifically of the IgG subclass and the variety of signaling receptors to which it binds render this an important immunomodulatory molecule. In addition to the classical Fcγ receptors (FcγR which bind IgG at the cell surface, the neonatal Fc receptor (FcRn is a lifelong resident of the endolysosomal system of most hematopoietic cells where it determines the intracellular fate of both IgG and IgG-containing immune complexes (IgG IC. Crosslinking of FcRn by multivalent IgG IC within antigen presenting cells such as dendritic cells (DC initiates specific mechanisms which result in trafficking of the antigen-bearing IgG IC into compartments from which the antigen can successfully be processed into peptide epitopes compatible with loading onto both MHC class I and II molecules. In turn, this enables the synchronous activation of both CD4+ and CD8+ T cell responses against the cognate antigen, thereby bridging the gap between the humoral and cellular branches of the adaptive immune response. Critically, FcRn-driven T cell priming is efficient at very low doses of antigen due to the exquisite sensitivity of the IgG-mediated antigen delivery system through which it operates. FcRn-mediated antigen presentation has important consequences in tissue compartments replete with IgG and serves not only to determine homeostatic immune activation at a variety of sites but also to induce inflammatory responses upon exposure to antigens perceived as foreign. Therapeutically targeting the pathway by which FcRn enables T cell activation in response to IgG IC is thus a highly attractive prospect not only for the treatment of diseases that are driven by immune complexes but also for manipulating local immune responses against defined antigens such as those present during infections and

  19. Antigen-activated dendritic cells ameliorate influenza A infections

    Boonnak, Kobporn; Vogel, Leatrice; Orandle, Marlene; Zimmerman, Daniel; Talor, Eyal; Subbarao, Kanta


    Influenza A viruses cause significant morbidity and mortality worldwide. There is a need for alternative or adjunct therapies, as resistance to currently used antiviral drugs is emerging rapidly. We tested ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2-microglobulin chain of the human MHC class I molecu...

  20. Oncogenic cancer/testis antigens

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J


    Recent developments have set the stage for immunotherapy as a supplement to conventional cancer treatment. Consequently, a significant effort is required to further improve efficacy and specificity, particularly the identification of optimal therapeutic targets for clinical testing. Cancer....../testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor...... immunology and immune escape suggests that targeting oncogenic antigens may be beneficial, meaning that identification of cancer/testis antigens with oncogenic properties is of high priority. Recent work from our lab and others provide evidence that many cancer/testis antigens, in fact, have oncogenic...

  1. Natural Selection Promotes Antigenic Evolvability

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P. D.; Brisson, D.


    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...

  2. Anvendelse af prostataspecifikt antigen. En oversigt

    Brasso, K; Skaarup, P; Roosen, Jens Ulrik; Iversen, Peter


    Since it was first introduced, measurement of prostate specific antigen has gained increasing interest, and prostate specific antigen is regarded as being the best tumour marker available. The antigen lacks cancer specificity, limiting the usefulness in early diagnosis, The use of prostate specific...... antigen in early diagnosis, staging, and in monitoring patients with prostate cancer is reviewed....

  3. Contrasting evolutionary histories of MHC class I and class II loci in grouse—Effects of selection and gene conversion

    Minias, Piotr; Bateson, Zachary W; Whittingham, Linda A; Johnson, Jeff A.; Oyler-McCance, Sara J.; Dunn, Peter O


    Genes of the major histocompatibility complex (MHC) encode receptor molecules that are responsible for recognition of intracellular and extracellular pathogens (class I and class II genes, respectively) in vertebrates. Given the different roles of class I and II MHC genes, one might expect the strength of selection to differ between these two classes. Different selective pressures may also promote different rates of gene conversion at each class. Despite these predictions, surprisingly few studies have looked at differences between class I and II genes in terms of both selection and gene conversion. Here, we investigated the molecular evolution of MHC class I and II genes in five closely related species of prairie grouse (Centrocercus and Tympanuchus) that possess one class I and two class II loci. We found striking differences in the strength of balancing selection acting on MHC class I versus class II genes. More than half of the putative antigen-binding sites (ABS) of class II were under positive or episodic diversifying selection, compared with only 10% at class I. We also found that gene conversion had a stronger role in shaping the evolution of MHC class II than class I. Overall, the combination of strong positive (balancing) selection and frequent gene conversion has maintained higher diversity of MHC class II than class I in prairie grouse. This is one of the first studies clearly demonstrating that macroevolutionary mechanisms can act differently on genes involved in the immune response against intracellular and extracellular pathogens.

  4. Association between HLA-DR1 and -DR3 antigens and unexplained repeated miscarriage

    Christiansen, O B; Ring, Mette; Rosgaard, A;


    antigens--other studies have been unable to demonstrate such associations. For the present meta-analysis, 18 cross-sectional or case-control studies (published or unpublished) reporting on frequencies of HLA-DR1 and -DR3 antigens among Caucasian women with unexplained repeated miscarriage were identified......Few, mostly small, studies have investigated the distribution of HLA class II antigens among women with unexplained recurrent miscarriage. Although some studies have reported statistically significant associations between this syndrome and certain HLA-DR antigens--especially the -DR1 and -DR3...... patients and because patients with only two miscarriages were included in many studies; this is defined as repeated miscarriage. The odds ratios of repeated miscarriage for the HLA-DR1 and -DR3 antigens were calculated for the individual studies and subsequently the pooled odds ratios for the studies were...

  5. Viral sequestration of antigen subverts cross presentation to CD8(+ T cells.

    Eric F Tewalt


    Full Text Available Virus-specific CD8(+ T cells (T(CD8+ are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC. Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector T(CD8+. Direct presentation of vaccinia virus (VACV antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated T(CD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the T(CD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation


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


    Archived serum samples, from 95 eastern cottontail rabbits (Sylvilagus floridanus) captured in New York, New York, USA and Millbrook, New York, USA, during 1985–86, were analyzed in solid-phase enzyme-linked immunosorbent assays (ELISA) for total and class-specific immunoglobulin (Ig) M antibodies to whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37...

  7. Distinctive localization of antigen-presenting cells in human lymph nodes

    Angel, Catherine E.; Chen, Chun-Jen J.; Horlacher, Oliver C.; Winkler, Sintia; John, Thomas; Browning, Judy; MacGregor, Duncan; Cebon, Jonathan; Dunbar, P. Rod


    Professional antigen-presenting cells (APCs) are sentinel cells of the immune system that present antigen to T lymphocytes and mediate an appropriate immune response. It is therefore surprising that knowledge of the professional APCs in human lymph nodes is limited. Using 3-color immunohistochemistry, we have identified APCs in human lymph nodes, excluding plasmacytoid APCs, that fall into 2 nonoverlapping classes: (1) CD209+ APCs, coexpressing combinations of CD206, CD14, and CD68, that occu...

  8. Evasion of peptide, but not lipid antigen presentation, through pathogen-induced dendritic cell maturation

    Hava, David L.; van der Wel, Nicole ,; Cohen, Nadia; Dascher, Christopher C.; Houben, Diane; León, Luis; Agarwal, Sandeep; Sugita, Masahiko; van Zon, Maaike; Kent, Sally C.; Shams, Homayoun; Peters, Peter J.; Brenner, Michael B.


    Dendritic cells (DC) present lipid and peptide antigens to T cells on CD1 and MHC Class II (MHCII), respectively. The relative contribution of these systems during the initiation of adaptive immunity after microbial infection is not characterized. MHCII molecules normally acquire antigen and rapidly traffic from phagolysosomes to the plasma membrane as part of DC maturation, whereas CD1 molecules instead continually recycle between these sites before, during, and after DC maturation. We find ...

  9. Antigen-specific memory Treg control memory responses to influenza virus infection

    Brincks, Erik L.; Roberts, Alan D.; Cookenham, Tres; Sell, Stewart; Kohlmeier, Jacob E.; Blackman, Marcia A.; Woodland, David L


    Regulatory CD4+FoxP3+ T cells (Treg) are key regulators of inflammatory responses and control the magnitude of cellular immune responses to viral infections. However, little is known about how Treg contribute to immune regulation during memory responses to previously-encountered pathogens. Here we utilized influenza NP311-325/IAb Class II tetramers to track the antigen-specific Treg response to primary and secondary influenza virus infections. During secondary infections, antigen-specific mem...

  10. Cancer associated aberrant protein o-glycosylation can modify antigen processing and immune response

    Madsen, Caroline B; Petersen, Cecilie; Lavrsen, Kirstine;


    response to a cancer related tumor antigen, Balb/c or B6.Cg(CB)-Tg(HLA-A/H2-D)2Enge/J (HLA-A2 transgenic) mice were immunized with a non-glycosylated or GalNAc-glycosylated MUC1 derived peptide followed by comparison of T cell proliferation, IFN-¿ release, and antibody induction. Gal...... abolished MUC1 specific CD8+ T cell responses in HLA-A2 transgenic mice. GalNAc glycosylation of MUC1 antigen therefore facilitates uptake, MHC class II presentation, and antibody response but might block the antigen presentation to CD8+ T cells....

  11. Potential Target Antigens for a Universal Vaccine in Epithelial Ovarian Cancer

    Renee Vermeij


    Full Text Available The prognosis of epithelial ovarian cancer (EOC, the primary cause of death from gynaecological malignancies, has only modestly improved over the last decades. Immunotherapeutic treatment using a cocktail of antigens has been proposed as a “universal” vaccine strategy. We determined the expression of tumor antigens in the context of MHC class I expression in 270 primary tumor samples using tissue microarray. Expression of tumor antigens p53, SP17, survivin, WT1, and NY-ESO-1 was observed in 120 (48.0%, 173 (68.9%, 208 (90.0%, 129 (56.3%, and 27 (11.0% of 270 tumor specimens, respectively. In 93.2% of EOC, at least one of the investigated tumor antigens was (overexpressed. Expression of MHC class I was observed in 78.1% of EOC. In 3 out 4 primary tumors, (overexpression of a tumor antigen combined with MHC class I was observed. These results indicate that a multiepitope vaccine, comprising these antigens, could serve as a universal therapeutic vaccine for the vast majority of ovarian cancer patients.

  12. Vaccine delivery by penetratin: mechanism of antigen presentation by dendritic cells.

    Pouniotis, Dodie; Tang, Choon-Kit; Apostolopoulos, Vasso; Pietersz, Geoffrey


    Cell-penetrating peptides (CPP) or membrane-translocating peptides such as penetratin from Antennapedia homeodomain or TAT from human immunodeficiency virus are useful vectors for the delivery of protein antigens or their cytotoxic (Tc) or helper (Th) T cell epitopes to antigen-presenting cells. Mice immunized with CPP containing immunogens elicit antigen-specific Tc and/or Th responses and could be protected from tumor challenges. In the present paper, we investigate the mechanism of class I and class II antigen presentation of ovalbumin covalently linked to penetratin (AntpOVA) by bone marrow-derived dendritic cells with the use of biochemical inhibitors of various pathways of antigen processing and presentation. Results from our study suggested that uptake of AntpOVA is via a combination of energy-independent (membrane fusion) and energy-dependent pathways (endocytosis). Once internalized by either mechanism, multiple tap-dependent or independent antigen presentation pathways are accessed while not completely dependent on proteasomal processing but involving proteolytic trimming in the ER and Golgi compartments. Our study provides an understanding on the mechanism of antigen presentation mediated by CPP and leads to greater insights into future development of vaccine formulations. PMID:27138940

  13. Distribution of class ii major histocompatibility complex antigenexpressing cells in human dental pulp with carious lesions

    Tetiana Haniastuti


    Background: Dental caries is a bacterial infection which causes destruction of the hard tissues of the tooth. Exposure of the dentin to the oral environment as a result of caries inevitably results in a cellular response in the pulp. The major histocompatibility complex (MHC) is a group of genes that code for cell-surface histocompatibility antigens. Cells expressing class II MHC molecules participate in the initial recognition and the processing of antigenic substances to serve as antigen-pr...

  14. Clinical implication of HLA class I expression in breast cancer

    Human leukocyte antigen (HLA)-class I molecules on tumor cells have been regarded as crucial sites where cytotoxic T lymphocytes (CTL) can recognize tumor-specific antigens and are strongly associated with anti-tumor activity. However, the clinical impact of HLA class I expression in breast cancer has not been clarified. A total of 212 breast cancer patients who received curative surgery from 1993 to 2003 were enrolled in the current study. HLA class I expression was examined immunohistochemically using an anti-HLA class I monoclonal antibody. The correlation between HLA class I positivity and clinical factors was analyzed. The downregulation of HLA class I expression in breast cancer was observed in 69 patients (32.5%). HLA class I downregulation was significantly associated with nodal involvement (p < 0.05), TNM stage (p < 0.05), lymphatic invasion (p < 0.01), and venous invasion (p < 0.05). Patients with preserved HLA class I had significantly better disease-free interval (DFI) than those with loss of HLA class I (p < 0.05). However, in multivariable analysis, HLA class I was not selected as one of the independent prognostic factors of disease-free interval. The examination of HLA class I expression is useful for the prediction of tumor progression and recurrent risk of breast cancer via the antitumor immune system

  15. Distinct roles for histone methyltransferases G9a and GLP in cancer germline antigen gene regulation in human cancer cells and murine ES cells

    Link, Petra A.; Gangisetty, Omkaram; James, Smitha R.; Woloszynska-Read, Anna; Tachibana, Makoto; Shinkai, Yoichi; Karpf, Adam R.


    The H3K9me2 histone methyltransferases G9a and GLP repress Mage-a class cancer germline (CG) antigen gene expression in murine ES cells but the role of these enzymes in CG antigen gene regulation in human cancer cells is unknown. Here we show that while independent or dual knockdown of G9a and GLP in human cancer cells leads to reduced global and CG antigen promoter-associated H3K9me2 levels it does not activate CG antigen gene expression. Moreover, CG antigen gene repression is maintained fo...

  16. Characterization of structural features controlling the receptiveness of empty class II MHC molecules

    Rupp, Bernd; Günther, Sebastian; Makhmoor, Talat;


    MHC class II molecules (MHC II) play a pivotal role in the cell-surface presentation of antigens for surveillance by T cells. Antigen loading takes place inside the cell in endosomal compartments and loss of the peptide ligand rapidly leads to the formation of a non-receptive state of the MHC mol...

  17. Molecular basis for the control of motor-based transport of MHC class II compartments

    Rocha, Nuno


    Antigen presentation by MHC class II is critical for immune responses against pathogens and tumors. Antigen loading occurs primarily in lysosomal-related organelles (LROs) known as MIICs. Ultimately, the MHC II-peptide complexes are transported for cell surface display. Here, we study intracellular

  18. Analysis of expression profiles of MAGE-A antigens in oral squamous cell carcinoma cell lines

    Reichert Torsten E


    Full Text Available Abstract Background The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential expression profiles also modulate the course of the cancer disease and its response to antineoplastic drugs. Methods The expression profiles of MAGE-A2, -A3, -A4, -A6 and -A10 in five own oral squamous cell carcinoma cell lines were characterised by rt-PCR, qrt-PCR and immunocytochemistry with a global MAGE-A antibody (57B and compared with those of an adult keratinocyte cell line (NHEK. Results All tumour cell lines expressed MAGE-A antigens. The antigens were expressed in groups with different preferences. The predominant antigens expressed were MAGE-A2, -A3 and -A6. MAGE-A10 was not expressed in the cell lines tested. The MAGE-A gene products detected in the adult keratinocyte cell line NHEK were used as a reference. Conclusion MAGE-A antigens are expressed in oral squamous cell carcinomas. The expression profiles measured facilitate distinct examinations in forthcoming studies on responses to antineoplastic drugs or radiation therapy. MAGE-A antigens are still an interesting aim for immunotherapy.

  19. Evolution of major histocompatibility complex class I and class II genes in the brown bear

    Kuduk Katarzyna


    Full Text Available Abstract Background Major histocompatibility complex (MHC proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae. Results We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (dN exceeded the rate of synonymous substitutions (dS at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Conclusions Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South–north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia.

  20. [Farmer's lung antigens in Germany].

    Sennekamp, J; Joest, M; Sander, I; Engelhart, S; Raulf-Heimsoth, M


    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

  1. Monoclonal Antibody Production against Human Spermatozoal Surface Antigens

    M Jedi-Tehrani


    Full Text Available Introduction: As monoclonal antibodies are potential tools for characterization of soluble or cellular surface antigens, use of these proteins has always been considered in infertility and reproduction research. Therefore, in this study, monoclonal antibodies against human sperm surface antigens were produced. Material and Methods: To produce specific clones against human sperm surface antigens, proteins were extracted using solubilization methods. Balb/c mice were immunized intraperitoneally with the proteins using complete Freund’s adjuvant in the first injection and incomplete Adjuvant in the following booster injections. Hybridoma cells producing ASA were cloned by limiting dilution. Results: Five stable ASA producing hybridoma clones were achieved and their antibody isotypes were determined by ELISA. All the isotypes were of IgG class. Their cross reactivity with rat and mice spermatozoa was examined but they did not have any cross reactivity. Conclusion: The produced antibodies can be used in further studies to characterize and evaluate each of the antigens present on human sperm surface and determining their role in fertilization.

  2. Major histocompatibility complex (MHC) antigens

    Hála, K.; Plachý, Jiří; Kaufman, J.

    New York : Academic Press, 1998 - (Pastoret, P.; Griebel, P.; Bazin, H.; Govaerts, A.), s. 92-95 ISBN 0-12-546401-0 R&D Projects: GA ČR GA523/96/0670 Keywords : chicken MHC * histocompatibility antigens * disease resistance Subject RIV: EB - Genetics ; Molecular Biology

  3. Class Vectors: Embedding representation of Document Classes

    Sachan, Devendra Singh; Kumar, Shailesh


    Distributed representations of words and paragraphs as semantic embeddings in high dimensional data are used across a number of Natural Language Understanding tasks such as retrieval, translation, and classification. In this work, we propose "Class Vectors" - a framework for learning a vector per class in the same embedding space as the word and paragraph embeddings. Similarity between these class vectors and word vectors are used as features to classify a document to a class. In experiment o...

  4. Teachers in Class

    Van Galen, Jane


    In this article, I argue for a closer read of the daily "class work" of teachers, as posited by Reay, 1998. In developing exploratory class portraits of four teachers who occupy distinctive social positions (two from working-class homes now teaching upper-middle-class children and two from upper-middle-class homes now teaching poor children), I…

  5. Probing the S1 specificity pocket of the aminopeptidases that generate antigenic peptides: S1 specificity of ERAP1, ERAP2 and IRAP

    Zervoudi, Efthalia; Papakyriakou, Athanasios; Georgiadou, Dimitra; Evnouchidou, Irini; Gajda, Anna; Poreba, Marcin; Salvesen, Guy S.; Drag, Marcin; Hattori, Akira; Swevers, Luc; Vourloumis, Dionisios; Stratikos, Efstratios


    ER aminopeptidase 1 (ERAP1), ER aminopeptidase 2 (ERAP2) and Insulin Regulated aminopeptidase (IRAP) are three homologous enzymes that play critical roles in the generation of antigenic peptides. These aminopeptidases excise amino acids from N-terminally extended precursors of antigenic peptides in order to generate the correct length epitopes for binding onto MHC class I molecules. The specificity of these peptidases can affect antigenic peptide selection, but has not yet been investigated i...

  6. Post-Transcriptional and Epigenetic Regulation of Antigen Processing Machinery (APM) Components and HLA-I in Cervical Cancers from Uighur Women

    HASIM, AYSHAMGUL; Abudula, Mangnishahan; Aimiduo, Reshalaiti; Ma, Jun-Qi; JIAO, Zhen; Akula, Gulzareye; Wang, Ting; ABUDULA, ABULIZI


    Normal function of human leukocyte antigen class I (HLA-I) and antigen processing machinery (APM) proteins is required for T cell-mediated anti-tumor or antiviral immunity, whereas the tumor survival indicates a failure of the host in immune surveillance associated with the dysfunction in antigen presentation, mainly due to the deregulation in HLA-I and APM expression or function. The posttranscriptional regulation of HLA-I and APM expression may associate with epigenetic modifications in can...

  7. Turnover of Ia-peptide complexes is facilitated in viable antigen-presenting cells: biosynthetic turnover of Ia vs. peptide exchange.

    Harding, C V; Roof, R W; Unanue, E R


    Macrophages and B cells process antigens to produce antigenic peptides that associate with class II major histocompatibility complex molecules (e.g., Ia molecules); these Ia-peptide complexes are recognized by CD4+ T lymphocytes. Processing of the antigen hen egg white lysozyme was inhibited by cycloheximide in peritoneal exudate cells (PECs, largely macrophages), but not in TA3 B-lymphoma cells. The uptake and metabolism of hen egg white lysozyme was largely intact in cycloheximide-treated P...

  8. Genome Scale Identification of Treponema pallidum Antigens

    McKevitt, Matthew; Brinkman, Mary Beth; McLoughlin, Melanie; Perez, Carla; Howell, Jerrilyn K.; Weinstock, George M.; Norris, Steven J; Palzkill, Timothy


    Antibody responses for 882 of the 1,039 proteins in the proteome of Treponema pallidum were examined. Sera collected from infected rabbits were used to systematically identify 106 antigenic proteins, including 22 previously identified antigens and 84 novel antigens. Additionally, sera collected from rabbits throughout the course of infection demonstrated a progression in the breadth and intensity of humoral immunoreactivity against a representative panel of T. pallidum antigens.

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

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


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

  10. Detection of O antigens in Escherichia coli

    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 ...