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Sample records for antigen class ii

  1. Swine Leukocyte Antigen (SLA) Class II is a Xenoantigen.

    PubMed

    Ladowski, Joseph M; Reyes, Luz M; Martens, Gregory R; Butler, James R; Wang, Zheng-Yu; Eckhoff, Devin E; Tector, Matt; Tector, A Joseph

    2017-08-24

    Over 130 000 patients in the United States alone need a life-saving organ transplant. Genetically modified porcine organs could resolve the donor organ shortage, but human xenoreactive antibodies destroy pig cells and are the major barrier to clinical application of xenotransplantation. The objective of this study was to determine whether waitlisted patients possess preformed antibodies to swine leukocyte antigen (SLA) class II, homologs of the class II human leukocyte antigens (HLA). Sera from people currently awaiting solid organ transplant were tested for IgG binding to class II SLA proteins when expressed on mammalian cells. Pig fibroblasts were made positive by transfection with the class II transactivator (CIITA). As a second expression system, transgenes encoding the alpha and beta chains of class II SLA were transfected into Human embryonic kidney (HEK293) cells. Human sera containing IgG specific for class II HLA molecules exhibited greater binding to class II SLA positive cells than to SLA negative cells. Sera lacking antibodies against class II HLA showed no change in binding regardless of the presence of class II SLA. These antibodies could recognize either SLA-DR or SLA-DQ complexes. Class II SLA proteins may behave as xenoantigens for people with humoral immunity towards class II HLA molecules.

  2. HLA class II antigen presentation by prostate cancer cells.

    PubMed

    Younger, A R; Amria, S; Jeffrey, W A; Mahdy, A E M; Goldstein, O G; Norris, J S; Haque, A

    2008-01-01

    Prostate cancer is the second most commonly diagnosed cancer in men. Recent evidence suggests that reduced expression of target protein antigens and human leukocyte antigen (HLA) molecules is the predominant immune escape mechanism of malignant prostate tumor cells. The purpose of this study was to investigate the prospect of antigen specific immunotherapy against prostate cancer via the HLA class II pathway of immune recognition. Here, we show for the first time that prostate cancer cells express HLA class II proteins that are recognized by CD4+ T cells. Prostate tumor cells transduced with class II molecules efficiently presented tumor-associated antigens/peptides to CD4+ T cells. This data suggests that malignant prostate tumors can be targeted via the HLA class II pathway, and that class II-positive tumors could be employed for direct antigen presentation, and CD4+ T-cell mediated tumor immunotherapy.Prostate Cancer and Prostatic Diseases (2008) 11, 334-341; doi:10.1038/sj.pcan.4501021; published online 16 October 2007.

  3. Expression of major histocompatibility complex class I and class II antigens in canine masticatory muscle myositis.

    PubMed

    Paciello, Orlando; Shelton, G Diane; Papparella, Serenella

    2007-04-01

    Studies in human immune-mediated inflammatory myopathies have documented expression of major histocompatibility complex class I (MHC class I) and class II (MHC class II) antigens on muscle fiber membranes in the presence or absence of cellular infiltration. Here we evaluate the presence and distribution of these antigens in canine masticatory muscle myositis, an immune-mediated inflammatory myopathy. Twelve samples of temporalis and masseter muscles from dogs with a clinical diagnosis of canine masticatory muscle myositis were examined by immunohistochemistry and double-immunofluorescence confocal microscopy. MHC class I and class II antigens were expressed in muscle fibers independent of inflammatory cell infiltration. Furthermore MHC class I and class II antigens were expressed on the sarcolemma and co-localized with dystrophin. Our results suggest that MHC class I and class II expression in canine masticatory muscle myositis may play a role in the initiation and maintenance of the pathological condition, rather than just a consequence of a preceding local inflammation.

  4. Class II HLA antigens in multiple sclerosis.

    PubMed Central

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

    1989-01-01

    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

  5. A central role for HSC70 in regulating antigen trafficking and MHC class II presentation.

    PubMed

    Deffit, Sarah N; Blum, Janice S

    2015-12-01

    Cells rely on multiple intracellular trafficking pathways to capture antigens for proteolysis. The resulting peptides bind to MHC class II molecules to promote CD4(+) T cell recognition. Endocytosis enhances the capture of extracellular and cell surface bound antigens for processing and presentation, while autophagy pathways shunt cytoplasmic and nuclear antigens for presentation in the context of MHC class II molecules. Understanding how physiological changes and cellular stress alter antigen trafficking and the repertoire of peptides presented by class II molecules remains challenging, yet important in devising novel approaches to boost immune responses to pathogens and tumors. An abundant, constitutively expressed cytoplasmic chaperone, HSC70 plays a central role in modulating antigen transport within cells to control MHC class II presentation during nutrient stress. HSC70 may serve as a molecular switch to modulate endocytic and autophagy pathways, impacting the source of antigens delivered for MHC class II presentation during cellular stress.

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

    PubMed Central

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

    2015-01-01

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

  7. HLA Class II Antigen Expression in Colorectal Carcinoma Tumors as a Favorable Prognostic Marker12

    PubMed Central

    Sconocchia, Giuseppe; Eppenberger-Castori, Serenella; Zlobec, Inti; Karamitopoulou, Eva; Arriga, Roberto; Coppola, Andrea; Caratelli, Sara; Spagnoli, Giulio Cesare; Lauro, Davide; Lugli, Alessandro; Han, Junyi; Iezzi, Giandomenica; Ferrone, Cristina; Ferlosio, Amedeo; Tornillo, Luigi; Droeser, Raoul; Rossi, Piero; Attanasio, Antonio; Ferrone, Soldano; Terracciano, Luigi

    2014-01-01

    The goal of this study was to determine the frequency of HLA class II antigen expression in colorectal carcinoma (CRC) tumors, its association with the clinical course of the disease, and the underlying mechanism(s). Two tissue microarrays constructed with 220 and 778 CRC tumors were stained with HLA-DR, DQ, and DP antigen-specific monoclonal antibody LGII-612.14, using the immunoperoxidase staining technique. The immunohistochemical staining results were correlated with the clinical course of the disease. The functional role of HLA class II antigens expressed on CRC cells was analyzed by investigating their in vitro interactions with immune cells. HLA class II antigens were expressed in about 25% of the 220 and 21% of the 778 tumors analyzed with an overall frequency of 23%. HLA class II antigens were detected in 19% of colorectal adenomas. Importantly, the percentage of stained cells and the staining intensity were significantly lower than those detected in CRC tumors. However, HLA class II antigen staining was weakly detected only in 5.4% of 37 normal mucosa tissues. HLA class II antigen expression was associated with a favorable clinical course of the disease. In vitro stimulation with interferon gamma (IFNγ) induced HLA class II antigen expression on two of the four CRC cell lines tested. HLA class II antigen expression on CRC cells triggered interleukin-1β (IL-1β) production by resting monocytes. HLA class II antigen expression in CRC tumors is a favorable prognostic marker. This association may reflect stimulation of IL-1β production by monocytes. PMID:24563618

  8. Negative regulation by HLA-DO of MHC class II-restricted antigen processing.

    PubMed

    Denzin, L K; Sant'Angelo, D B; Hammond, C; Surman, M J; Cresswell, P

    1997-10-03

    HLA-DM is a major histocompatibility complex (MHC) class II-like molecule that facilitates antigen processing by catalyzing the exchange of invariant chain-derived peptides (CLIP) from class II molecules for antigenic peptides. HLA-DO is a second class II-like molecule that physically associates with HLA-DM in B cells. HLA-DO was shown to block HLA-DM function. Purified HLA-DM-DO complexes could not promote peptide exchange in vitro. Expression of HLA-DO in a class II+ and DM+, DO- human T cell line caused the accumulation of class II-CLIP complexes, indicating that HLA-DO blocked DM function in vivo and suggesting that HLA-DO is an important modulator of class II-restricted antigen processing.

  9. Detection of functional class II-associated antigen: role of a low density endosomal compartment in antigen processing

    PubMed Central

    1995-01-01

    We have developed a functional assay to identify processed antigen in subcellular fractions from antigen-presenting cells; stimulatory activity in this assay may be caused by either free peptide fragments or by complexes of peptide fragments and class II molecules present on organellar membrane sheets and vesicles. In addition, we have developed a functional assay to identify proteolytic activity in subcellular fractions capable of generating antigenic peptides from intact proteins. These techniques permit the direct identification of intracellular sites of antigen processing and class II association. Using a murine B cell line stably transfected with a phosphorylcholine (PC)-specific membrane-bound immunoglobulin (Ig), we show that PC- conjugated antigens are rapidly internalized and efficiently degraded to generate processed antigen within an early low density compartment. Proteolytic activity capable of generating antigenic peptide fragments from intact proteins is found within low density endosomes and a dense compartment consistent with lysosomes. However, neither processed peptide nor peptide-class II complexes are detected in lysosomes from antigen-pulsed cells. Furthermore, blocking the intracellular transport of internalized antigen from the low density endosome to lysosomes does not inhibit the generation of processed antigen. Therefore, antigens internalized in association with membrane Ig on B cells can be efficiently processed in low density endosomal compartments without the contribution of proteases present within denser organelles. PMID:7722450

  10. Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation

    PubMed Central

    Wieczorek, Marek; Abualrous, Esam T.; Sticht, Jana; Álvaro-Benito, Miguel; Stolzenberg, Sebastian; Noé, Frank; Freund, Christian

    2017-01-01

    Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell’s own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors—tapasin for class I and HLA-DM for class II—contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity. PMID:28367149

  11. Comparison of Class II HLA antigen expression in normal and carcinomatous human breast cells

    SciTech Connect

    Bernard, D.J.; Maurizis, J.C.; Chassagne, J.; Chollet, P.; Plagne, R.

    1985-03-01

    Class II HLA antigen expression in breast carcinoma and normal breast gland cells was compared using a method more accurate than immunofluorescence. This new method involves labeling membrane proteins with /sup 131/I and the anti-Class II HLA monoclonal antibody with /sup 125/I. The isolation and purification of the doubly labeled (/sup 125/I-/sup 131/I) immune complex was performed by affinity chromatography and chromatofocusing successively. When the specific activity of glycoproteins is known, the amount of glycoprotein which bind specifically to the anti-Class II HLA monoclonal antibody can be deduced. In breast carcinoma cells, 1.5 to 2% of the purified glycoproteins bind specifically to the monoclonal antibody, whereas less than 0.3% of normal breast gland cells binds. In contrast, leukemic cells, of which 80 to 90% possess Class II HLA antigens, 2 to 3% of Class II HLA glycoproteins bind specifically with the anti-Class II HLA monoclonal antibody.

  12. Angiotensin-converting enzyme affects the presentation of MHC class II antigens.

    PubMed

    Zhao, Tuantuan; Bernstein, Kenneth E; Fang, Jianmin; Shen, Xiao Z

    2017-07-01

    Antigen processing and presentation through the MHC class II pathway is critical for activating T helper cells. Angiotensin-converting enzyme (ACE) is a carboxyl peptidase expressed by antigen-presenting cells. By analysis of ACE null (knockout), wild-type, and ACE-overexpressing (ACE10) mice and the antigen-presenting cells derived from these mice, we found that ACE has a physiological role in the processing of peptides for MHC class II presentation. The efficiency of presenting MHC class II epitopes from ovalbumin (OVA) and hen egg lysosome is markedly affected by cellular ACE levels. Mice overexpressing ACE in myeloid cells have a much more vigorous CD4(+) T-cell and antibody response when immunized with OVA. ACE is present in the endosomal pathway where MHC class II peptide processing and loading occur. The efficiency of MHC class II antigen presentation can be altered by ACE overexpression or ACE pharmacological inhibition. Thus, ACE is a dynamic participant in processing MHC class II peptides. Manipulation of ACE expression by antigen-presenting cells may prove to be a novel strategy to alter the immune response.

  13. Protein sorting within the MHC class II antigen-processing pathway.

    PubMed

    Marks, M S

    1998-01-01

    Major histocompatibility complex (MHC) class II molecules are required for the presentation of antigenic peptides that are derived predominantly from internalized proteins. The assembly of MHC class II/peptide complexes occurs within endosomal compartments of antigen-presenting cells (APCs). Therefore, for assembly to occur, MHC class II molecules, foreign proteins, and accessory molecules must be sorted to appropriate intracellular sites. My laboratory is trying to understand how proteins are sorted to various antigen-processing compartments as well as to conventional endosomal organelles. Using chimeric marker proteins and a variety of biochemical and genetic approaches, we are addressing the specificity of protein sorting and the mechanisms by which sorting signals are deciphered. By using a similar chimeric protein approach to target endogenous proteins to distinct compartments, we hope to address the role of processing events in each compartment in the generation of MHC class II ligands.

  14. Major histocompatibility complex class II antigen expression in B and T cell non-Hodgkin's lymphoma.

    PubMed Central

    Smith, M E; Holgate, C S; Williamson, J M; Grigor, I; Quirke, P; Bird, C C

    1987-01-01

    An immunohistochemical study of 46 B and T cell non-Hodgkin's lymphomas, using monoclonal antibodies to the products of the major histocompatibility complex (MHC) class II antigen subregions, DP, DQ, and DR, showed that most B and T cell lymphomas express these antigens. Both coordinate and non-coordinate expression of MHC class II antigens was observed, but this did not correlate with immunological phenotype, morphological grade, or proliferation index as determined by flow cytometry. Images Fig 1 Fig 2 Fig 3 PMID:3546388

  15. Polymer blend particles with defined compositions for targeting antigen to both class I and II antigen presentation pathways.

    PubMed

    Tran, Kenny K; Zhan, Xi; Shen, Hong

    2014-05-01

    Defense against many persistent and difficult-to-treat diseases requires a combination of humoral, CD4(+) , and CD8(+) T-cell responses, which necessitates targeting antigens to both class I and II antigen presentation pathways. In this study, polymer blend particles are developed by mixing two functionally unique polymers, poly(lactide-co-glycolide) (PLGA) and a pH-responsive polymer, poly(dimethylaminoethyl methacrylate-co-propylacrylic acid-co-butyl methacrylate) (DMAEMA-co-PAA-co-BMA). Polymer blend particles are shown to enable the delivery of antigens into both class I and II antigen presentation pathways in vitro. Increasing the ratio of the pH-responsive polymer in blend particles increases the degree of class I antigen presentation, while maintaining high levels of class II antigen presentation. In a mouse model, it is demonstrated that a significantly higher and sustained level of CD4(+) and CD8(+) T-cell responses, and comparable antibody responses, are elicited with polymer blend particles than PLGA particles and a conventional vaccine, Alum. The polymer blend particles offer a potential vaccine delivery platform to generate a combination of humoral and cell-mediated immune responses that insure robust and long-lasting immunity against many infectious diseases and cancers.

  16. Polymer blend particles with defined compositions for targeting antigen to both class I and II antigen presentation pathways

    PubMed Central

    Tran, Kenny K.; Zhan, Xi; Shen, Hong

    2013-01-01

    Defense against many persistent and difficult-to-treat diseases requires a combination of humoral, CD4+ and CD8+ T cell responses, which necessitates targeting antigens to both class I and II antigen presentation pathways. In this study, we developed polymer blend particles by mixing two functionally unique polymers, poly(lactide-co-glycolide) (PLGA) and a pH-responsive polymer, poly(dimethylaminoethyl methacrylate-co-propylacrylic acid-co-butyl methacrylate) (DMAEMA-co-PAA-co-BMA). We showed polymer blend particles enabled the delivery of antigens into both class I and II antigen presentation pathways in vitro. Increasing the ratio of the pH-responsive polymer in blend particles increased the degree of class I antigen presentation, while maintaining high levels of class II antigen presentation. In a mouse model, we demonstrated that a significantly higher and sustained level of CD4+ and CD8+ T cell responses, and comparable antibody responses, were elicited with polymer blend particles than PLGA particles and a conventional vaccine, Alum. The polymer blend particles offer a potential vaccine delivery platform to generate a combination of humoral and cell-mediated immune responses that insure robust and long-lasting immunity against many infectious diseases and cancers. PMID:24124123

  17. The overlooked "nonclassical" functions of major histocompatibility complex (MHC) class II antigens in immune and nonimmune cells.

    PubMed

    Altomonte, M; Pucillo, C; Maio, M

    1999-06-01

    Besides their "classical" antigenic peptide-presenting activity, major histocompatibility complex (MHC) class II antigens can activate different cellular functions in immune and nonimmune cells. However, this "nonclassical" role and its functional consequences are still substantially overlooked. In this review, we will focus on these alternative functional properties of MHC class II antigens, to reawaken attention to their present and foreseeable immunobiologic and pathogenetic implications. The main issues that will be addressed concern 1) the role of MHC class II molecules as basic components of exchangeable oligomeric protein complexes with intracellular signaling ability; 2) the nonclassical functions of MHC class II antigens in immune cells; 3) the pathogenetic role of MHC class II antigens in inflammatory/autoimmune and infectious disease; and 4) the functional role of MHC class II antigens in solid malignancies.

  18. Dendritic cell preactivation impairs MHC class II presentation of vaccines and endogenous viral antigens

    PubMed Central

    Young, Louise J.; Wilson, Nicholas S.; Schnorrer, Petra; Mount, Adele; Lundie, Rachel J.; La Gruta, Nicole L.; Crabb, Brendan S.; Belz, Gabrielle T.; Heath, William R.; Villadangos, Jose A.

    2007-01-01

    When dendritic cells (DCs) encounter signals associated with infection or inflammation, they become activated and undergo maturation. Mature DCs are very efficient at presenting antigens captured in association with their activating signal but fail to present subsequently encountered antigens, at least in vitro. Such impairment of MHC class II (MHC II) antigen presentation has generally been thought to be a consequence of down-regulation of endocytosis, so it might be expected that antigens synthesized by the DCs themselves (for instance, viral antigens) would still be presented by mature DCs. Here, we show that DCs matured in vivo could still capture and process soluble antigens, but were unable to present peptides derived from these antigens. Furthermore, presentation of viral antigens synthesized by the DCs themselves was also severely impaired. Indeed, i.v. injection of pathogen mimics, which caused systemic DC activation in vivo, impaired the induction of CD4 T cell responses against subsequently encountered protein antigens. This immunosuppressed state could be reversed by adoptive transfer of DCs loaded exogenously with antigens, demonstrating that impairment of CD4 T cell responses was due to lack of antigen presentation rather than to overt suppression of T cell activation. The biochemical mechanism underlying this phenomenon was the down-regulation of MHC II–peptide complex formation that accompanied DC maturation. These observations have important implications for the design of prophylactic and therapeutic DC vaccines and contribute to the understanding of the mechanisms causing immunosuppression during systemic blood infections. PMID:17978177

  19. Differential expression of HLA class II antigens on human fetal and adult lymphocytes and macrophages.

    PubMed Central

    Edwards, J A; Jones, D B; Evans, P R; Smith, J L

    1985-01-01

    A panel of monoclonal antibodies to monomorphic determinants of the MHC class II subregion locus products: DP, DR and DQ, was used to investigate the expression of these antigens on early lymphocytes and macrophages from human fetal liver (13-20 weeks), placenta (16 weeks and term) and cord blood, in relation to the class II phenotype of cells from adult tonsil and peripheral blood. Fetal liver sections and cell suspensions showed differential expression of class II antigens. DP was expressed at a higher frequency (11.0% of nucleated cells) than DR on lymphoid cells and macrophages from fetal liver, and DQ was either absent or expressed on less than 0.3% of nucleated cells. Consistent with this finding, DP but not DR or DQ antigens were observed on vascular elements and macrophages in the villi of 16-week placenta. At term, all three subregion locus products were expressed. Adult tonsil and peripheral blood B lymphocytes expressed DP, DR and DQ antigens with similar frequency; however, DQ was expressed at a lower frequency than DP and DR on cord blood B lymphocytes. In contrast, 30-50% macrophages from cord blood and adult peripheral blood expressed DP and DR, but fewer (5% and 18%, respectively) expressed DQ. These data suggest that class II antigens are expressed in the sequence DP, DR, DQ on developing lymphocytes. A similar sequence is suggested for macrophages. Images Figure 1 Figure 2 Figure 3 PMID:3894221

  20. Studying MHC class II presentation of immobilized antigen by B lymphocytes.

    PubMed

    Yuseff, M I; Lennon-Dumenil, A M

    2013-01-01

    The ability of B lymphocytes to capture external antigens (Ag) and present them as peptide fragments, loaded on Major Histocompatibility complex (MHC) class II molecules, to CD4(+) T cells is a crucial part of the adaptive immune response. This allows T-B cooperation, a cellular communication that is required for B cells to develop into germinal centers (GC) and form mature high-affinity antibody producing cells and to further develop B cell memory. MHC class II antigen presentation by B lymphocytes is a multistep process involving (1) Recognition and capture of external Ag by B lymphocytes through their B cell receptor (BCR); (2) Ag processing, which comprises the degradation of Ag in internal compartments within the B cell and loading of the corresponding peptide fragments on MHC class II molecules and (3) Presentation of MHC II-peptide complexes to CD4(+) T cells. Here, we describe how to study MHC class II antigen presentation by B lymphocytes at these three major levels.

  1. Toward a Network Model of MHC Class II-Restricted Antigen Processing

    PubMed Central

    Miller, Michael A.; Ganesan, Asha Purnima V.; Eisenlohr, Laurence C.

    2013-01-01

    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. PMID:24379819

  2. Ubiquitination by March-I prevents MHC class II recycling and promotes MHC class II turnover in antigen-presenting cells

    PubMed Central

    Cho, Kyung-Jin; Walseng, Even; Ishido, Satoshi; Roche, Paul A.

    2015-01-01

    MHC class II (MHC-II)-dependent antigen presentation by antigen-presenting cells (APCs) is carefully controlled to achieve specificity of immune responses; the regulated assembly and degradation of antigenic peptide–MHC-II complexes (pMHC-II) is one aspect of such control. In this study, we have examined the role of ubiquitination in regulating pMHC-II biosynthesis, endocytosis, recycling, and turnover in APCs. By using APCs obtained from MHC-II ubiquitination mutant mice, we find that whereas ubiquitination does not affect pMHC-II formation in dendritic cells (DCs), it does promote the subsequent degradation of newly synthesized pMHC-II. Acute activation of DCs or B cells terminates expression of the MHC-II E3 ubiquitin ligase March-I and prevents pMHC-II ubiquitination. Most importantly, this change results in very efficient pMHC-II recycling from the surface of DCs and B cells, thereby preventing targeting of internalized pMHC-II to lysosomes for degradation. Biochemical and functional assays confirmed that pMHC-II turnover is suppressed in MHC-II ubiquitin mutant DCs or by acute activation of wild-type DCs. These studies demonstrate that acute APC activation blocks the ubiquitin-dependent turnover of pMHC-II by promoting efficient pMHC-II recycling and preventing lysosomal targeting of internalized pMHC-II, thereby enhancing pMHC-II stability for efficient antigen presentation to CD4 T cells. PMID:26240324

  3. Ubiquitination by March-I prevents MHC class II recycling and promotes MHC class II turnover in antigen-presenting cells.

    PubMed

    Cho, Kyung-Jin; Walseng, Even; Ishido, Satoshi; Roche, Paul A

    2015-08-18

    MHC class II (MHC-II)-dependent antigen presentation by antigen-presenting cells (APCs) is carefully controlled to achieve specificity of immune responses; the regulated assembly and degradation of antigenic peptide-MHC-II complexes (pMHC-II) is one aspect of such control. In this study, we have examined the role of ubiquitination in regulating pMHC-II biosynthesis, endocytosis, recycling, and turnover in APCs. By using APCs obtained from MHC-II ubiquitination mutant mice, we find that whereas ubiquitination does not affect pMHC-II formation in dendritic cells (DCs), it does promote the subsequent degradation of newly synthesized pMHC-II. Acute activation of DCs or B cells terminates expression of the MHC-II E3 ubiquitin ligase March-I and prevents pMHC-II ubiquitination. Most importantly, this change results in very efficient pMHC-II recycling from the surface of DCs and B cells, thereby preventing targeting of internalized pMHC-II to lysosomes for degradation. Biochemical and functional assays confirmed that pMHC-II turnover is suppressed in MHC-II ubiquitin mutant DCs or by acute activation of wild-type DCs. These studies demonstrate that acute APC activation blocks the ubiquitin-dependent turnover of pMHC-II by promoting efficient pMHC-II recycling and preventing lysosomal targeting of internalized pMHC-II, thereby enhancing pMHC-II stability for efficient antigen presentation to CD4 T cells.

  4. Presence of antibodies against self human leukocyte antigen class II molecules in autoimmune hepatitis.

    PubMed

    Yamagiwa, Satoshi; Kamimura, Hiroteru; Takamura, Masaaki; Genda, Takuya; Ichida, Takafumi; Nomoto, Minoru; Aoyagi, Yutaka

    2014-01-01

    Autoimmune hepatitis (AIH) can arise de novo after liver transplantation (LT) for non-autoimmune liver diseases. Considering the identical features of de novo AIH after LT and classical AIH, as well as the importance of anti-human leukocyte antigen (HLA) antibodies in graft rejection, we investigated the presence of circulating anti-HLA class II antibodies in the sera of 35 patients with AIH, 30 patients with primary biliary cirrhosis (PBC), and 30 healthy donors using fluorescent dye-impregnated beads bound to HLA molecules. We then investigated the allele specificity of the antibodies and identified the HLA alleles in each patient using DNA-based HLA typing. We also examined HLA class II expression in liver samples using immunohistochemistry. Anti-HLA class II antibodies were detected significantly more frequently in the patients with AIH (88.1%) than in the patients with PBC (33.3%) or in the healthy donors (13.3%) (both P <0.01). We confirmed that the anti-HLA class II antibodies in the AIH patients showed specificity for several HLA class II alleles, including self HLA class II alleles. Moreover, positive reactivity with anti-self HLA class II antibodies was associated with higher serum transaminase levels. In conclusion, we demonstrated, for the first time, that antibodies against self HLA class II alleles were detectable in patients with AIH. Our results suggest that an antibody-mediated immune response against HLA class II molecules on hepatocytes may be involved in the pathogenesis or acceleration of liver injury in AIH.

  5. The Other Function: Class II-Restricted Antigen Presentation by B Cells

    PubMed Central

    Adler, Lital N.; Jiang, Wei; Bhamidipati, Kartik; Millican, Matthew; Macaubas, Claudia; Hung, Shu-chen; Mellins, Elizabeth D.

    2017-01-01

    Mature B lymphocytes (B cells) recognize antigens using their B cell receptor (BCR) and are activated to become antibody-producing cells. In addition, and integral to the development of a high-affinity antibodies, B cells utilize the specialized major histocompatibility complex class II (MHCII) antigen presentation pathway to process BCR-bound and internalized protein antigens and present selected peptides in complex with MHCII to CD4+ T cells. This interaction influences the fate of both types of lymphocytes and shapes immune outcomes. Specific, effective, and optimally timed antigen presentation by B cells requires well-controlled intracellular machinery, often regulated by the combined effects of several molecular events. Here, we delineate and summarize these events in four steps along the antigen presentation pathway: (1) antigen capture and uptake by B cells; (2) intersection of internalized antigen/BCRs complexes with MHCII in peptide-loading compartments; (3) generation and regulation of MHCII/peptide complexes; and (4) exocytic transport for presentation of MHCII/peptide complexes at the surface of B cells. Finally, we discuss modulation of the MHCII presentation pathway across B cell development and maturation to effector cells, with an emphasis on the shaping of the MHCII/peptide repertoire by two key antigen presentation regulators in B cells: HLA-DM and HLA-DO. PMID:28386257

  6. MHC Class II tetramers and the pursuit of antigen-specific T cells: define, deviate, delete.

    PubMed

    Mallone, Roberto; Nepom, Gerald T

    2004-03-01

    Selective expansion and activation of a very small number of antigen-specific CD4(+) T cells is a remarkable and essential property of the adaptive immune response. Antigen-specific T cells were until recently identified only indirectly by functional assays, such as antigen-induced cytokine secretion and proliferation. The advent of MHC Class II tetramers has added a pivotal tool to our research armamentarium, allowing the definition of allo- and autoimmune responses in deeper detail. Rare antigen-specific CD4(+) cells can now be selectively identified, isolated and characterized. The same tetramer reagents also provide a new mean of stimulating T cells, more closely reproducing the MHC-peptide/TCR interaction. This property allows the use of tetramers to direct T cells toward the more desirable outcome, that is, activation (in malignancies and infectious diseases) or Th2/T regulatory cell deviation, anergy and deletion (in autoimmune diseases). These experimental approaches hold promise for diagnostic, prognostic and therapeutic applications.

  7. Isotypic and allotypic variation of human class II histocompatibility antigen alpha-chain genes.

    PubMed

    Auffray, C; Lillie, J W; Arnot, D; Grossberger, D; Kappes, D; Strominger, J L

    DNA sequences of four human class II histocompatibility antigen alpha chain DNA sequences (derived from cDNA and genomic clones representing DC1 alpha, DC4 alpha, DX alpha and SB alpha) are presented and compared to DR alpha and to mouse I-A alpha and I-E alpha sequences. These data suggest possible mechanisms for the generation of polymorphism and the evolution of the DR, DC and SB families.

  8. 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).

    PubMed Central

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

    1987-01-01

    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 that the surface HLA-DR antigens are also internalized by receptor-mediated endocytosis in Langerhans and indeterminate cells. Moreover, using immunogold double labeling, we demonstrate that T6 and HLA-DR antigens are internalized through common coated regions of the membrane of Langerhans or indeterminate cells. The receptor-mediated endocytosis that is induced involves coated pits and vesicles, receptosomes, lysosomes, and also, in Langerhans cells, the Birbeck granules. Thus, T6 antigens, which are considered to be "unusual" or "nonclassical" major histocompatibility complex class I molecules, and the major histocompatibility complex class II molecules, HLA-DR, are internalized in Langerhans and indeterminate cells through common receptor-mediated endocytosis organelles. Images PMID:3106979

  9. Stress-induced alterations in interferon production and class II histocompatibility antigen expression

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, G.; Cunnick, J. E.; Armfield, A. V.; Wood, P. G.; Rabin, B. S.

    1992-01-01

    Mild electric foot-shock has been shown to be a stressor that can alter immune responses. Male Lewis rats were exposed to one session of 16 5.0-s 1.6-mA foot-shocks. Production of interferon-gamma by splenocytes in response to concanavalin-A was decreased in spleens from the shocked rats compared to control spleens. Spleen cells from rats treated with nadolol, a peripherally acting beta-adrenergic receptor antagonist, and then shocked, showed dose-dependent attenuation of the suppression of interferon-gamma production. This suggests that catecholamines mediate shock-induced suppression of interferon-gamma production. The percentage of splenic mononuclear cells expressing class II histocompatibility (Ia) antigens on their surfaces from spleens of shocked rats was determined by flow cytometry. Significantly decreased class II positive mononuclear cells were present in the spleens of shocked rats in comparison to the spleens of control rats. This may reflect an alteration of cell trafficking or decreased production of class II antigens.

  10. Ectopic expression of HLA-DO in mouse dendritic cells diminishes MHC class II antigen presentation.

    PubMed

    Fallas, Jennifer L; Tobin, Helen M; Lou, Olivia; Guo, Donglin; Sant'Angelo, Derek B; Denzin, Lisa K

    2004-08-01

    The MHC class II-like molecule HLA-DM (DM) (H-2M in mice) catalyzes the exchange of CLIP for antigenic peptides in the endosomes of APCs. HLA-DO (DO) (H-2O in mice) is another class II-like molecule that is expressed in B cells, but not in other APCs. Studies have shown that DO impairs or modifies the peptide exchange activity of DM. To further evaluate the role of DO in Ag processing and presentation, we generated transgenic mice that expressed the human HLA-DOA and HLA-DOB genes under the control of a dendritic cell (DC)-specific promoter. Our analyses of DCs from these mice showed that as DO levels increased, cell surface levels of A(b)-CLIP also increased while class II-peptide levels decreased. The presentation of some, but not all, exogenous Ags to T cells or T hybridomas was significantly inhibited by DO. Surprisingly, H-2M accumulated in DO-expressing DCs and B cells, suggesting that H-2O/DO prolongs the half-life of H-2M. Overall, our studies showed that DO expression impaired H-2M function, resulting in Ag-specific down-modulation of class II Ag processing and presentation.

  11. Human leukocyte antigen (HLA) class I and II alleles in Turkish patients with rheumatic heart disease.

    PubMed

    Gündogdu, Fuat; Islamoglu, Yahya; Pirim, Ibrahim; Gurlertop, Yekta; Dogan, Hasan; Arslan, Sakir; Sevimli, Serdar; Aksakal, Enbiya; Senocak, Huseyin

    2007-05-01

    Rheumatic heart disease (RHD) is often preceded by rheumatic fever (RF). The disease is a multisystem inflammatory condition that develops as a sequel to untreated throat infection by group A beta-hemolytic streptococci. Several studies have suggested that genetic susceptibility to RHD may be linked to human leukocyte antigen (HLA) class II alleles. The study aim was to investigate the association between RHD and the antigens HLA-A, -B, -C, -DR and -DQ profile in RHD patients in eastern Turkey. A case-control study was conducted which included 85 unrelated patients with RHD, and 85 control subjects. The diagnosis was supported by echocardiography and histories of RHD of those patients who underwent valve replacement. The association of class I and class II HLA antigens was examined in RHD and control subjects using a sequence-specific primer (SSP) method. The phenotypes HLA-B51, -Cw*4 and -DRB1*01 were encountered in significantly lower frequencies in patients with RHD compared to the control population (p <0.05, p <0.05, p <0.05, respectively). There was also a significant increase in antigen frequency of HLA-DQB1*08 in RHD patients compared to controls (p <0.005). Among the studied population, the results suggested that susceptibility to RHD was HLA-related, with HLA-DQB1*08 most likely influencing the occurrence of the condition. HLA-B51, -Cw*4 and -DRB1*01 appeared to be more common in control subjects.

  12. Supernatants of human leukocytes contain mediator, different from interferon gamma, which induces expression of MHC class II antigens

    PubMed Central

    1986-01-01

    In this report, data are presented on the regulation of MHC class II antigen expression by a mediator present in supernatants of human mixed leukocyte cultures (MLC-SN), and which is different from IFN-gamma. The capacity of supernatants to induce antigen expression did not correspond to titers of IFN-gamma. Removal of IFN-gamma using either dialysis against pH 2 or neutralizing mAb against human IFN-gamma did not abrogate the MHC class II antigen expression-inducing capacity of MLC-SN when tested on adenocarcinoma cell lines, kidney epithelial cells, and fibroblasts in vitro in an indirect immunofluorescence assay. Therefore, supernatants of human leukocytes contain a mediator, different from IFN-gamma, which induces expression of MHC class II antigens. Dose-response studies revealed that the mediator is produced after allogeneic and lectin stimulation of human leukocytes, and by unstimulated leukocytes. Activation of leukocytes resulted in increased titers of the mediator. The mediator markedly enhances expression of both HLA-DR and HLA-DQ antigens, whereas IFN-gamma had a similar effect on HLA-DR antigens, and only a minor effect on HLA-DQ antigens. Interaction of the mediator and IFN-gamma resulted in a potentiating effect of these two factors on MHC class II antigen expression. Biochemical analysis revealed a mediator, distinguishable by FPLC from IL-1, IL-2, and human IFN-gamma, and which has a molecular mass of 32 kD. PMID:2941512

  13. Antigen-specific tumor vaccine efficacy in vivo against prostate cancer with low class I MHC requires competent class II MHC.

    PubMed

    Neeley, Yilin C; McDonagh, Kevin T; Overwijk, Willem W; Restifo, Nicholas P; Sanda, Martin G

    2002-11-01

    Cancers can escape immune recognition by means of evading class I major histocompatibility complex (MHC) -mediated recognition by cytotoxic T lymphocytes. However, immunization strategies targeting defined tumor-associated antigens have not been extensively characterized in murine prostate cancer models. Therefore, we evaluated antigen-specific, antitumor immunity after antigen-encoding vaccinia immunization against mouse prostate cancer cells expressing a model tumor-associated antigen (beta-galactosidase) and exhibiting partially deficient class I MHC. Low class I MHC expression in beta-galactosidase-expressing D7RM-1 prostate cancer cells was shown by fluorescence activated cell sorting, and deficient class I MHC-mediated antigen presentation was shown in resistance of D7RM-1 to cytolysis by beta-galactosidase-specific cytotoxic T lymphocytes (CTL). Despite partially deficient class I MHC presenting function, immunization with vaccinia encoding beta-galactosidase conferred antigen-specific protection against D7RM-1 cancer. Antigen-specific immunity was recapitulated in beta(2)m knockout mice (with deficient class I MHC and CTL function), confirming that class I MHC antigen presentation was not required for immunity against tumor partially deficient in class I MHC. Conversely, antigen-specific antitumor immunity was abrogated in A(b)beta knockout mice (with deficient class II MHC and helper T cell function), demonstrating a requirement for functional class II MHC. Resistant tumors from the otherwise effectively immunized beta(2)m knockout mice (among which tumor progression had been reduced or delayed) showed reduced target antigen expression, corroborating antigen-specificity (and showing an alternative immune escape mechanism), whereas antigen expression (like tumor growth) was unaffected among A(b)beta knockout mice. Our results demonstrate that class I MHC-restricted antigen presentation and CTL activity is neither necessary nor sufficient for antigen

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

    PubMed

    Tipu, Hamid Nawaz; Ahmed, Tahir Aziz; Bashir, Mohammad Mukarram

    2011-01-01

    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. Department of Immunology, Armed Forces Institute of Pathology, Rawalpindi, from January 2009 to April 2010. 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.

  15. Mutations and selection in the generation of class II histocompatibility antigen polymorphism.

    PubMed Central

    Gustafsson, K; Wiman, K; Emmoth, E; Larhammar, D; Böhme, J; Hyldig-Nielsen, J J; Ronne, H; Peterson, P A; Rask, L

    1984-01-01

    A comparison of seven human DR and DC class II histocompatibility antigen beta-chain amino acid sequences indicates that the allelic variation is of comparable magnitude within the DR and DC beta-chain genes. Silent and replacement nucleotide substitutions in six DR and DC beta-chain sequences, as well as in seven murine class II sequences (three I-A beta and four I-A alpha alleles) were analyzed. The results suggest that the mutation rates are of a comparable magnitude in the nucleotide sequences encoding the first and second external domains of the class II molecules. Nevertheless, the allelic amino acid replacements are predominantly located in the first domains. We conclude that a conservative selective pressure acts on the second domains, whereas in many positions in the first domains replacement substitutions are selectively neutral or maybe even favoured. Thus, the difference between the first and second domains as regards the number of amino acid replacements is mainly due to selection. PMID:6589154

  16. HLA Class II Antigen Presentation in Prostate Cancer Cells: A Novel Approach to Prostate Tumor Immunotherapy.

    PubMed

    Doonan, Bently Patrick; Haque, Azizul

    2010-01-01

    Prostate cancer is a deadly disease that is in drastic need of new treatment strategies for late stage and metastatic prostate cancer. Immunotherapy has emerged as a viable option to fill this void. Clinical trials have been conducted that induce tumor clearance through cytotoxic T lymphocyte (CTL) activation, these studies have had mixed outcomes with the overlying problem being the lack of a complete immune response with sustained killing and the formation of tumor specific memory cells. To overcome this, we have outlined the need for activating the HLA class II pathway in inducing a sustained CD8+ T cell response and the development of effective memory. We have also discussed the ability of prostate cancer cells to express stable HLA class II molecules that can be manipulated for tumor antigen (Ag) processing and presentation. This review also sets to outline new directions that exist for the use of class II-restricted Ags/peptides in devising cancer vaccines as well as combined chemoimmunotherapy. A better understanding of these concepts will improve future cancer vaccine studies and further the field of cancer immunobiology.

  17. Association of chronic fatigue syndrome with human leucocyte antigen class II alleles

    PubMed Central

    Smith, J; Fritz, E L; Kerr, J R; Cleare, A J; Wessely, S; Mattey, D L

    2005-01-01

    Background: A genetic component to the development of chronic fatigue syndrome (CFS) has been proposed, and a possible association between human leucocyte antigen (HLA) class II antigens and chronic fatigue immune dysfunction has been shown in some, but not all, studies. Aims: To investigate the role of HLA class II antigens in CFS. Methods: Forty nine patients with CFS were genotyped for the HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles and the frequency of these alleles was compared with a control group comprising 102 normal individuals from the UK. All patients and controls were from the same region of England and, apart from two patients, were white. Results: Analysis by 2 × 2 contingency tables revealed an increased frequency of HLA-DQA1*01 alleles in patients with CFS (51.0% v 35%; odds ratio (OR), 1.93; p  =  0.008). HLA-DQB1*06 was also increased in the patients with CFS (30.2% v 20.0%; OR, 1.73, p  =  0.052). Only the association between HLA-DQA1*01 and CFS was significant in logistic regression models containing HLA-DQA1*01 and HLA-DRQB1*06, and this was independent of HLA-DRB1 alleles. There was a decreased expression of HLA-DRB1*11 in CFS, although this association disappeared after correction for multiple comparisons. Conclusions: CFS may be associated with HLA-DQA1*01, although a role for other genes in linkage disequilibrium cannot be ruled out. PMID:16049290

  18. Expanded dog leukocyte antigen (DLA) single nucleotide polymorphism (SNP) genotyping reveals spurious class II associations

    PubMed Central

    Safra, N.; Pedersen, N.C.; Wolf, Z.; Johnson, E.G.; Liu, H.W.; Hughes, A.M.; Young, A.; Bannasch, D.L.

    2011-01-01

    The dog leukocyte antigen (DLA) system contains many of the functional genes of the immune system, thereby making it a candidate region for involvement in immune-mediated disorders. A number of studies have identified associations between specific DLA class II haplotypes and canine immune hemolytic anemia, thyroiditis, immune polyarthritis, type I diabetes mellitus, hypoadrenocorticism, systemic lupus erythematosus-related disease complex, necrotizing meningoencephalitis (NME) and anal furunculosis. These studies have relied on sequencing approximately 300 bases of exon 2 of each of the DLA class II genes: DLA-DRB1, DLA-DQA1 and DLA-DQB1. An association (odds ratio = 4.29) was identified by this method between Weimaraner dogs with hypertrophic osteodystrophy (HOD) and DLA-DRB1*01501. In the present study, a genotyping assay of 126 coding single nucleotide polymorphisms (SNPs) from across the entire DLA, spanning a region of 2.5 Mb (3,320,000–5,830,000) on CFA12, was developed and tested on Weimaraners with HOD, as well as two additional breeds with diseases associated with DLA class II: Nova Scotia duck tolling retrievers with hypoadrenocorticism and Pug dogs with NME. No significant associations were found between Weimaraners with HOD or Nova Scotia duck tolling retrievers with hypoadrenocorticism and SNPs spanning the DLA region. In contrast, significant associations were found with NME in Pug dogs, although the associated region extended beyond the class II genes. By including a larger number of genes from a larger genomic region a SNP genotyping assay was generated that provides coverage of the extended DLA region and may be useful in identifying and fine mapping DLA associations in dogs. PMID:21741283

  19. Antibodies against denatured HLA class II molecules detected in luminex-single antigen assay.

    PubMed

    Grenzi, Patricia C; de Marco, Renato; Silva, Rosemeire Z R; Campos, Erika F; Gerbase-DeLima, Maria

    2013-10-01

    False-positive anti-HLA reactions may occur in Luminex-single antigen (SA) beads assays, and it is important to recognize them to correctly interpret the test. The purpose of this report is to describe a peculiar pattern of reactivity, characterized by positivity with beads coated with HLA-DRB1*09:01, DRB3*01:01, DRB3*02:02, DRB3*03:01, DPB1*02:01, DPB1*20:01 and DPB1*28:01, that was observed in 141 of 8121 serum samples tested in our laboratory with three different lots of the same kit (LABScreen(®) SA, One Lambda). These 141 serum samples came from 56 different patients on the kidney transplant waiting list, corresponding to 1% of the patients. Of these, 10 males had never been transfused or transplanted. About 66% of the patients had positive reactions against self-antigen HLA-DRB3 alleles. No reactions against native HLA-DRB1*09:01 were observed in flow cytometry crossmatch and in absorption/elution experiments, leading to the conclusion that the reactivity was due to antibodies against epitopes present in denatured forms of HLA-class II antigens. The occurrence of this reactivity pattern was associated with female gender and systemic lupus erythematosus (SLE).

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

    PubMed Central

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

    1987-01-01

    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. Images Fig. 1 Fig. 2 Fig. 3 PMID:3115648

  1. Association of Campylobacter pylori with induced expression of class II transplantation antigens on gastric epithelial cells.

    PubMed Central

    Engstrand, L; Scheynius, A; Påhlson, C; Grimelius, L; Schwan, A; Gustavsson, S

    1989-01-01

    Campylobacter pylori was identified with immunoperoxidase staining and a mouse monoclonal antibody directed against C. pylori in gastric biopsy specimens from 24 patients with gastritis. C. pylori was not found in gastric biopsy specimens from six subjects with histologically normal mucosa. The monoclonal antibody, which was reactive with a surface protein of approximately 20 kilodaltons, was found to be specific for C. pylori, and the immunoperoxidase staining proved to be more sensitive and rapid than culture in detecting the organism. In the tissue specimens where C. pylori was detected with the monoclonal antibody, there was a strong expression of class II transplantation antigens on the epithelial cells and an increased number of T lymphocytes. These findings indicate that C. pylori may initiate local immune responses. Images PMID:2645211

  2. Class I and class II HLA antigens in a homogeneous Argentinian population with Whipple's disease: lack of association with HLA-B 27.

    PubMed

    Bai, J C; Mota, A H; Mauriño, E; Niveloni, S; Grossman, F; Boerr, L A; Fainboim, L

    1991-08-01

    The prevalence of class I and class II HLA antigen was analyzed in 14 patients (12 males, two females) with Whipple's disease, diagnosed an average of 9.7 yr (range 6 months to 25 yr) before the typing. They were compared with 174 healthy control subjects of the same geographic area in Argentina. Class I antigens (locus A, B, C) were studied by lymphocytotoxic test, and class II antigens (locus DR, DQ) were detected by the double immunofluorescence technique. HLA-B27 was positive in one patient (7.7%) and in 4% of the control population. No significant association was found with the antigens tested. We observed no difference in the clinical picture or in the frequency of arthralgias, compared with those reported in the literature. Our data suggest that there is no conclusive proof of an association between HLA-B27 and Whipple's disease.

  3. Human leukocyte antigen class I and II alleles in non-Hodgkin lymphoma etiology

    PubMed Central

    Abdou, Amr M.; Morton, Lindsay M.; Thomas, Rasmi; Cerhan, James R.; Gao, Xiaojiang; Cozen, Wendy; Rothman, Nathaniel; Davis, Scott; Severson, Richard K.; Bernstein, Leslie; Hartge, Patricia; Carrington, Mary

    2010-01-01

    Genome-wide association and candidate gene studies implicate different genetic variants within the 6p21 chromosomal region with different non-Hodgkin lymphoma (NHL) subtypes. Complementing these efforts, we conducted human leukocyte antigen (HLA) class I and class II genotyping among 610 NHL cases and 555 controls of non-Hispanic white descent from a US multicenter study. Allele-disease associations were assessed by logistic regression for NHL and its subtypes. Statistically significant associations between HLA and NHL subtypes include HLA-DRB1*0101 for follicular lymphoma (odds ratio [OR] = 2.14, P < .001), HLA-DRB1*0401 for diffuse large B-cell lymphoma (DLBCL; OR = 0.45, P = .006), and HLA-DRB1*13 and follicular lymphoma (OR = 0.48, P = .008). We further observed significant heterozygote advantage for HLA class I alleles and NHL, and particularly DLBCL (P trend = .01 for elevated risk with increasing number of homozygous alleles). Our results support a role for HLA in the etiology of NHL and its subtypes. PMID:20385791

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

    PubMed Central

    Sundqvist, Emilie; Buck, Dorothea; Warnke, Clemens; Albrecht, Eva; Gieger, Christian; Khademi, Mohsen; Lima Bomfim, Izaura; Fogdell-Hahn, Anna; Link, Jenny; Alfredsson, Lars; Søndergaard, Helle Bach; Hillert, Jan; Oturai, Annette B.; Hemme, Bernhard

    2014-01-01

    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 JCV infection, were compared to HLA class I and II alleles in 1621 Scandinavian persons with MS and 1064 population-based Swedish controls and associations were replicated in 718 German persons with MS. HLA-alleles were determined by SNP imputation, sequence specific (SSP) kits and a reverse PCR sequence-specific oligonucleotide (PCR-SSO) method. An initial GWAS screen displayed a strong HLA class II region signal. The HLA-DRB1*15 haplotype was strongly negatively associated to JCV sero-status in Scandinavian MS cases (OR = 0.42, p = 7×10−15) and controls (OR = 0.53, p = 2×10−5). In contrast, 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 II restricted immune responses, and hence CD4+ T cell immunity is pivotal for JCV infection control. Alleles within the HLA-DR1*15 haplotype are associated with a protective effect on JCV infection. Alleles within the DQB1*06:03 haplotype show an opposite association. These associations between JC virus antibody response and human leucocyte antigens supports the notion that CD4+ T cells are crucial in the immune defence to JCV and lays

  5. HLA-DO as the Optimizer of Epitope Selection for MHC Class II Antigen Presentation

    PubMed Central

    Poluektov, Yuri O.; Kim, AeRyon; Hartman, Isamu Z.; Sadegh-Nasseri, Scheherazade

    2013-01-01

    Processing of antigens for presentation to helper T cells by MHC class II involves HLA-DM (DM) and HLA-DO (DO) accessory molecules. A mechanistic understanding of DO in this process has been missing. The leading model on its function proposes that DO inhibits the effects of DM. To directly study DO functions, we designed a recombinant soluble DO and expressed it in insect cells. The kinetics of binding and dissociation of several peptides to HLA-DR1 (DR1) molecules in the presence of DM and DO were measured. We found that DO reduced binding of DR1 to some peptides, and enhanced the binding of some other peptides to DR1. Interestingly, these enhancing and reducing effects were observed in the presence, or absence, of DM. We found that peptides that were negatively affected by DO were DM-sensitive, whereas peptides that were enhanced by DO were DM-resistant. The positive and negative effects of DO could only be measured on binding kinetics as peptide dissociation kinetics were not affected by DO. Using Surface Plasmon Resonance, we demonstrate direct binding of DO to a peptide-receptive, but not a closed conformation of DR1. We propose that DO imposes another layer of control on epitope selection during antigen processing. PMID:23951115

  6. Bare lymphocyte syndrome. Consequences of absent class II major histocompatibility antigen expression for B lymphocyte differentiation and function.

    PubMed Central

    Clement, L T; Plaeger-Marshall, S; Haas, A; Saxon, A; Martin, A M

    1988-01-01

    The bare lymphocyte syndrome is a rare combined immunodeficiency disorder associated with the absence of class I and/or class II major histocompatibility (MHC) antigens. Although it has been inferred that the immune deficiency is a consequence of disordered MHC-restricted interactions among otherwise normal cells, the biological capabilities and differentiation of B lymphocytes deficient in class II MHC antigens have not been rigorously analyzed. We have examined the phenotypic and functional attributes of B cells with absent class II MHC antigens. Our data demonstrate that these B cells are intrinsically defective in their responses to membrane-mediated activation stimuli. In addition, virtually all the B cells had phenotypic evidence of arrested differentiation at an immature stage. Finally, these B cells also failed to express the C3d-EBV receptor normally present on all B lymphocytes. These data indicate that class II MHC molecules are vital participants in early events of the B cell activation cascade, and that other non-MHC membrane molecules may also be absent as a consequence of either arrested differentiation or as a result of the basic defect affecting the expression of MHC membrane antigens. PMID:3257764

  7. New Design of MHC Class II Tetramers to Accommodate Fundamental Principles of Antigen Presentation

    PubMed Central

    Landais, Elise; Romagnoli, Pablo A.; Corper, Adam L.; Shires, John; Altman, John D.; Wilson, Ian A.; Garcia, K. Christopher; Teyton, Luc

    2009-01-01

    Direct identification and isolation of antigen-specific T cells became possible with the development of “MHC tetramers”, based on fluorescent avidins displaying biotinylated peptide-MHC (pMHC) complexes. This approach, extensively used for MHC class I–restricted T cells, has met very limited success with MHC class II tetramers (pMHCT-2) for the detection of CD4+ specific T cells. In addition, a very large number of these reagents while capable of specifically activating T cells after being coated on solid support, are still unable to stain. In order to try to understand this puzzle and design usable tetramers, we examined each parameter critical for the production of pMHCT-2 using the I-Ad-OVA system as a model. Through this process the geometry of pMHC display by avidin tetramers was examined, as well as the stability of recombinant MHC molecules. However, we discovered that the most important factor limiting the reactivity of pMHCT-2 was the display of peptides. Indeed, long peptides, as presented by MHC class II molecules, can be bound to I-A/HLA-DQ molecules in more than one register as suggested by structural studies. This mode of anchorless peptide binding allows the selection of a broader repertoire on single peptides and should favor anti-infectious immune responses. Thus, beyond the technical improvements that we propose, the redesign of pMHCT-2 will give us the tools to evaluate the real size of the CD4 repertoire and help us in the production and testing of new vaccines. PMID:19923463

  8. Human leucocyte antigen (HLA) class I and II typing in Belgian multiple sclerosis patients.

    PubMed

    Lysandropoulos, Andreas P; Racapé, Judith; Holovska, Vanda; Toungouz, Michel

    2017-03-01

    This is one of the first studies to compare the frequencies of different human leucocyte antigen (HLA) class I and II alleles and haplotype HLA-DRB1*15-DQB1*06 in a cohort of 119 patients with multiple sclerosis (MS) and a cohort of 124 healthy controls in Belgium. An association with MS was found for the HLA-DRB1*15 (odds ratio [OR] 2.60 [95% confidence interval (CI) 1.51-4.50]) and HLA-DQB1*06 (OR 1.97 [95% CI 1.18-3.29]) alleles, and for haplotype DRB1*15-DQB1*06 (OR 2.63 [95% CI 1.52-4.56]). The HLA-B*07 allele also tended to be more frequent in MS patients (OR 1.46 [95% CI 0.80-2.65]) and more frequent among MS patients with than in those without the HLA-DRB1*15 allele (26/54 [48.1%] versus 6/65 [9.2%]; p value <0.0001). Other alleles were underrepresented in MS patients, such as the HLA-DRB1*07 (OR 0.39 [95% CI 0.21-0.73]) and HLA-A*02 (OR 0.56 [95% CI 0.34-0.94]), showing a protective role against the disease. The HLA-B*44 (OR 0.58 [95% CI 0.31-1.09]) and HLA-DRB1*04 (OR 0.75 [95% CI 0.42-1.34]) alleles tended to be less frequent in MS patients. Altogether, the significant results observed in this population are in line with those from other countries and confirm that propensity to MS can be due to a complex presence of various HLA class I and class II alleles.

  9. Phenotypic characterization of mononuclear cells and class II antigen expression in angular cheilitis infected by Candida albicans or Staphylococcus aureus.

    PubMed

    Ohman, S C; Jontell, M; Jonsson, R

    1989-04-01

    In the present study we characterized the phenotypes of infiltrating mononuclear cells in angular cheilitis lesions to further explore the pathogenesis of this disorder. Frozen sections from lesions infected by Candida albicans and/or Staphylococcus aureus were subjected to immunohistochemical analysis utilizing monoclonal antibodies directed to subsets of T-lymphocytes, B-lymphocytes, and macrophages. In addition, the expression of Class II antigens (HLA-DP, -DQ, -DR), the interleukin 2- and transferrin-receptors was studied on resident and infiltrating cells. An intense infiltration of T-lymphocytes was accompanied by expression of Class II antigens on the epidermal keratinocytes in lesion infected by Candida albicans. The Staphylococcus aureus infected lesions displayed a diffuse infiltration of T-lymphocytes but virtually no expression of Class II antigen by epidermal keratinocytes. These observations suggest that the cell-mediated arm of the immune system is involved in the inflammatory reaction of lesions infected by Candida albicans. In addition, the present study confirms that epidermal expression of Class II antigens is closely related to the type and magnitude of the infiltrating T-lymphocyte. Finally, these findings indicate that the type of inflammatory reaction in angular cheilitis is primarily dependent on the isolated microorganism, although the clinical pictures of the disorder are virtually identical.

  10. Characterization of the lymphocyte activation gene 3-encoded protein. A new ligand for human leukocyte antigen class II antigens

    PubMed Central

    1992-01-01

    The lymphocyte activation gene 3 (LAG-3), expressed in human activated T and natural killer (NK) cells, is closely related to CD4 at the gene and protein levels. We report here the initial characterization of the LAG-3-encoded protein. We have generated two monoclonal antibodies after immunization of mice with a 30-amino acid peptide that corresponds to an exposed extra loop region present in the LAG-3 immunoglobulin-like first domain. The reactivity of these reagents is directed against LAG-3 since they recognize both membrane-expressed and soluble recombinant LAG-3 molecules produced in a baculovirus expression system. The two antibodies are likely to react with the same or closely related epitope (termed LAG-3.1) exposed on the LAG-3 first domain extra loop, as assessed in competition experiments on LAG-3- expressing activated lymphocytes. Cellular distribution analysis indicated that the LAG-3.1 epitope is expressed on activated T (both CD4+ and CD8+ subsets) and NK cells, and not on activated B cells or monocytes. In immunoprecipitation experiments performed on activated T and NK cell lysates, a 70-kD protein was detected after SDS-PAGE analysis. 45-kD protein species were also immunoprecipitated. Both the 70- and 45-kD proteins were shown to be N-glycosylated. In Western blot analysis, only the former molecule was recognized by the anti-LAG-3 antibodies, demonstrating that it is LAG-3 encoded. These anti-LAG-3 antibodies were used to investigate whether the LAG-3 protein interacts with the CD4 ligands. By using a high-level expression cellular system based on COS-7 cell transfection with recombinant CDM8 vectors and a quantitative cellular adhesion assay, we demonstrate that rosette formation between LAG-3-transfected COS-7 cells and human leukocyte antigen (HLA) class II-bearing B lymphocytes is specifically dependent on LAG-3/HLA class II interaction. In contrast to CD4, LAG-3 does not bind the human immunodeficiency virus gp120. This initial

  11. Exogenous antigens bind MHC class II first, and are processed by cathepsins later.

    PubMed

    Sadegh-Nasseri, Scheherazade; Kim, AeRyon

    2015-12-01

    The field of antigen processing and presentation is likely one of the most well defined areas in immunology based on decades of intense molecular and structural studies. Many molecules contributing to antigen processing and presentation have been discovered and their mechanisms of action been largely defined, yet a major question, which lies at the very core of the field has remained hard to pin down. The question is what determines immunodominance? Immunodominance is defined as a few specific epitopes being selected to represent an antigen to the immune system and provide targets for T cells. Many studies have aimed at understanding how epitopes are selected. A range of hypotheses related to the structural features of antigens, sensitivity to proteases, epitope affinity for MHC II, T cell precursor frequency, and T cell receptor affinity for peptide/MHC II have been considered. However, because of the variety of proteins and factors involved in antigen processing and enormous complexity, finding an answer has been challenging. Here we make an effort to tease out the sequence of events in antigen processing that promote selection of immunodominant epitopes for exogenous antigens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. MHC class II expression and potential antigen-presenting cells in the retina during experimental autoimmune uveitis.

    PubMed

    Lipski, Deborah A; Dewispelaere, Rémi; Foucart, Vincent; Caspers, Laure E; Defrance, Matthieu; Bruyns, Catherine; Willermain, François

    2017-07-18

    MHC class II-associated antigen presentation and in T cell activation than non-hematopoietic cells. Our results highlight the potential of cells of hematopoietic origin in local antigen presentation, whatever their Ly6C expression. Our work further provides a first transcriptomic study of MHC class II-expressing retinal cells during EAU and delivers a series of new candidate genes possibly implicated in the pathogenesis of retinal autoimmunity.

  13. Identification of T cell subsets and class I and class II antigen expression in islet grafts and pancreatic islets of diabetic BioBreeding/Worcester rats.

    PubMed Central

    Weringer, E. J.; Like, A. A.

    1988-01-01

    The BioBreeding/Worcester (BB/Wor) rat develops a spontaneous disorder that closely resembles human insulin-dependent (Type I) diabetes mellitus. The syndrome is preceded by lymphocytic insulitis that destroys pancreatic beta cells. The morphologic features of the spontaneous insulitis lesions are also observed within islets transplanted beneath the renal capsule of diabetes-prone and diabetic animals. This study reports the results of experiments in which immunohistochemical techniques were used to characterize the phenotype of the infiltrating mononuclear cells and detect the expression of class I and class II MHC antigens in native islets and islet transplants in diabetic and diabetes-prone BB/Wor rats. The infiltrates within native pancreatic islets and islet grafts were comprised predominantly of Ia+ cells (dendritic cells and macrophages) CD4+ cells (helper/inducer lymphocytes and macrophages), CD5+ (pan-T) cells and smaller numbers of CD8+ (cytotoxic/suppressor and NK) cells. Pancreatic and graft insulitis were accompanied by markedly enhanced class I antigen expression on islet and exocrine cells. Class II (Ia) antigens were not detected on normal islet cells, islets undergoing insulitis or on islet transplants subjected to immune attack. In islet grafts stained with polymorphic MAbs that distinguish Ia antigens of donor and host origin, Ia antigen expression was limited to infiltrating dendritic cells and macrophages of host origin. It is concluded that the phenotypes of infiltrating mononuclear cells that comprise the insulitis lesion in spontaneous BB/Wor diabetes, and the inflammatory attack on islets transplanted into diabetic BB/Wor rats are the same, that pancreatic islet and graft insulitis occur in the presence of enhanced class I antigen expression but in the absence of class II antigen expression, and that infiltrating Ia+ cells within islet grafts are exclusively of recipient (BB/Wor) origin and may explain the initiation of immune insulitis

  14. Analysis of Class II human leucocyte antigens in Italian and Spanish systemic sclerosis.

    PubMed

    Beretta, Lorenzo; Rueda, Blanca; Marchini, Maurizio; Santaniello, Alessandro; Simeón, Carmen P; Fonollosa, Vicente; Caronni, Monica; Rios-Fernandez, Raquel; Carreira, Patricia; Rodriguez-Rodriguez, Luis; Moreno, Antonia; López-Nevot, Miguel A; Escalera, Ana; González-Escribano, Maria F; Martin, Javier; Scorza, Raffaella

    2012-01-01

    To determine the role of Class II HLAs in SSc patients from Italy and Spain and in SSc patients of Caucasian ancestry. Nine hundred and forty-four SSc patients (Italy 392 patients; Spain 452 patients) and 1320 ethnically matched healthy controls (Italy 398 patients; Spain 922 patients) were genotyped up to the fourth digit by PCR with sequence-specific oligonucleotides for HLA-DRB1, DQA1 and DQB1 loci. Patients included 390 ACA-positive and 254 anti-topo I-positive subjects. Associations between SSc or SSc-specific antibodies and HLA alleles or HLA haplotypes were sought via the chi-square test after 10 000-fold permutation testing. A meta-analysis including this study cohort and other Caucasoids samples was also conducted. In both the cohorts, the strongest association was observed between the HLA-DRB1*1104 allele and SSc or anti-topo I antibodies. The HLA-DRB1*1104 -DQA1*0501 -DQB1*0301 haplotype was overrepresented in Italian [odds ratio (OR) = 2.069, 95% asymptotic CIs (CI(95)) 1.486, 2.881; P < 0.001] and in Spanish patients (OR = 6.707, CI(95) 3.974, 11.319; P < 0.001) as well as in anti-topo-positive patients: Italy (OR = 2.642, CI(95) 1.78, 3.924; P < 0.001) and Spain (OR = 20.625, CI(95) 11.536, 36.876; P < 0.001). In both the populations we also identified an additional risk allele (HLA-DQB1*03) and a protective allele (HLA-DQB1*0501) in anti-topo-positive patients. The meta-analysis showed different statistically significant associations, the most interesting being the differential association between HLA-DRB1*01 alleles and ACAs (OR = 1.724, CI(95) 1.482, 2.005; P < 0.001) or topo I antibodies (OR = 0.5, CI(95) 0.384, 0.651; P < 0.001). We describe multiple robust associations between SSc and HLA Class II antigens in Caucasoids that may help to understand the genetic architecture of SSc.

  15. Analysis of Class II human leucocyte antigens in Italian and Spanish systemic sclerosis

    PubMed Central

    Rueda, Blanca; Marchini, Maurizio; Santaniello, Alessandro; Simeón, Carmen P.; Fonollosa, Vicente; Caronni, Monica; Rios-Fernandez, Raquel; Carreira, Patricia; Rodriguez-Rodriguez, Luis; Moreno, Antonia; López-Nevot, Miguel A.; Escalera, Ana; González-Escribano, Maria F.; Martin, Javier; Scorza, Raffaella

    2012-01-01

    Objective. To determine the role of Class II HLAs in SSc patients from Italy and Spain and in SSc patients of Caucasian ancestry. Methods. Nine hundred and forty-four SSc patients (Italy 392 patients; Spain 452 patients) and 1320 ethnically matched healthy controls (Italy 398 patients; Spain 922 patients) were genotyped up to the fourth digit by PCR with sequence-specific oligonucleotides for HLA-DRB1, DQA1 and DQB1 loci. Patients included 390 ACA-positive and 254 anti-topo I-positive subjects. Associations between SSc or SSc-specific antibodies and HLA alleles or HLA haplotypes were sought via the chi-square test after 10 000-fold permutation testing. A meta-analysis including this study cohort and other Caucasoids samples was also conducted. Results. In both the cohorts, the strongest association was observed between the HLA-DRB1*1104 allele and SSc or anti-topo I antibodies. The HLA-DRB1*1104 -DQA1*0501 -DQB1*0301 haplotype was overrepresented in Italian [odds ratio (OR) = 2.069, 95% asymptotic CIs (CI95) 1.486, 2.881; P < 0.001] and in Spanish patients (OR = 6.707, CI95 3.974, 11.319; P < 0.001) as well as in anti-topo-positive patients: Italy (OR = 2.642, CI95 1.78, 3.924; P < 0.001) and Spain (OR = 20.625, CI95 11.536, 36.876; P < 0.001). In both the populations we also identified an additional risk allele (HLA-DQB1*03) and a protective allele (HLA-DQB1*0501) in anti-topo-positive patients. The meta-analysis showed different statistically significant associations, the most interesting being the differential association between HLA-DRB1*01 alleles and ACAs (OR = 1.724, CI95 1.482, 2.005; P < 0.001) or topo I antibodies (OR = 0.5, CI95 0.384, 0.651; P < 0.001). Conclusions. We describe multiple robust associations between SSc and HLA Class II antigens in Caucasoids that may help to understand the genetic architecture of SSc. PMID:22087014

  16. Selective development of CD4+ T cells in transgenic mice expressing a class II MHC-restricted antigen receptor.

    PubMed

    Kaye, J; Hsu, M L; Sauron, M E; Jameson, S C; Gascoigne, N R; Hedrick, S M

    1989-10-26

    T lymphocytes are predisposed to recognition of foreign protein fragments bound to cell-surface molecules encoded by the major histocompatibility complex (MHC). There is now compelling evidence that this specificity is a consequence of a selection process operating on developing T lymphocytes in the thymus. As a result of this positive selection, thymocytes that express antigen receptors with a threshold affinity for self MHC-encoded glycoproteins preferentially emigrate from the thymus and seed peripheral lymphoid organs. The specificity for both foreign antigen and MHC molecules is imparted by the alpha and beta chains of the T-cell antigen receptor (TCR). Two other T-cell surface proteins, CD4 and CD8, which bind non-polymorphic regions of class II and class I MHC molecules respectively, are also involved in these recognition events and play an integral role in thymic selection. In order to elucidate the developmental pathways of class II MHC-restricted T cells in relation to these essential accessory molecules, we have produced TCR-transgenic mice expressing a receptor specific for a fragment of pigeon cytochrome c and the Ek (class II MHC) molecule. The transgenic TCR is expressed on virtually all T cells in mice expressing Ek. The thymuses of these mice contain an abnormally high percentage of mature CD4+CD8- cells. In addition, the peripheral T-cell population is almost exclusively CD4+, demonstrating that the MHC specificity of the TCR determines the phenotype of T cells during selection in the thymus.

  17. Association of human leukocyte antigen class II alleles with severe Middle East respiratory syndrome-coronavirus infection.

    PubMed

    Hajeer, Ali H; Balkhy, Hanan; Johani, Sameera; Yousef, Mohammed Z; Arabi, Yaseen

    2016-01-01

    Middle East Respiratory Syndrome (MERS) is a disease of the lower respiratory tract and is characterized by high mortality. It is caused by a beta coronavirus (CoV) referred to as MERS-CoV. Majority of MERS-CoV cases have been reported from Saudi Arabia. We investigated the human leukocyte antigen (HLA) Class II alleles in patients with severe MERS who were admitted in our Intensive Care Unit. A total of 23 Saudi patients with severe MERS-CoV infection were typed for HLA class II, results were compared with those of 161 healthy controls. Two HLA class II alleles were associated with the disease; HLA-DRB1*11:01 and DQB1*02:02, but not with the disease outcome. Our results suggest that the HLA-DRB1*11:01 and DQB1*02:02 may be associated with susceptibility to MERS.

  18. Participation of the interstitium in acute immune-complex nephritis: interstitial antigen accumulation, cellular infiltrate, and MHC class II expression

    PubMed Central

    PARRA, G; HERNÁNDEZ, S; MORENO, P; RODRÍGUEZ-ITURBE, B

    2003-01-01

    Bovine serum albumin (BSA) injected into the rabbits induces acute immune complex glomerulonephritis. Since albumin is filtered and reabsorbed in the tubules, we investigated whether tubulointerstitial cells participate in the pathogenesis of this experimental condition. For this purpose, we induced immune-complex nephritis in 45 rabbits with the injection of 125I-BSA and urinary BSA excretion, glomerular and tubulointerstitial BSA accumulation, lymphocyte infiltration, proliferative activity and MHC class II antigens were examined 2, 4–5 and 6–8 days after immunization. Proteinuria developed day 6–8. BSA was found in urine from day 2 (mean ± SE; 1089 ± 339 µg/24 h) and peaked on day 4 after immunization (2249 ± 1106). BSA content (cpm/g tissue) in tubulointerstitium (TI) and glomeruli were similar at day 2 (457 ± 45 and 407 ± 75, respectively), but afterward increased significantly in TI, reaching a peak level on day 5 (1026 ± 406) while remained unchanged in glomeruli (388 ± 95). At the same time, preceding the onset of proteinuria, maximal intensity of the lymphocyte infiltration, proliferative activity and MHC class II antigen expression in tubular cells, monocytes/macrophages and interstitial cells were observed. Our study shows that antigen is excreted in the urine and concentrated in TI in association with overexpression of MHC class II molecules and lymphocyte infiltration. These findings occur prior to the development of proteinuria and suggest that the tubulointerstitial cells play a critical role in the pathogenesis of this model. PMID:12823277

  19. Antigen Targeting to Human HLA Class II Molecules Increases Efficacy of DNA Vaccination

    PubMed Central

    Fredriksen, Agnete Brunsvik; Løset, Geir Åge; Vikse, Elisabeth; Fugger, Lars

    2016-01-01

    It has been difficult to translate promising results from DNA vaccination in mice to larger animals and humans. Previously, DNA vaccines encoding proteins that target Ag to MHC class II (MHC-II) molecules on APCs have been shown to induce rapid, enhanced, and long-lasting Ag-specific Ab titers in mice. In this study, we describe two novel DNA vaccines that as proteins target HLA class II (HLA-II) molecules. These vaccine proteins cross-react with MHC-II molecules in several species of larger mammals. When tested in ferrets and pigs, a single DNA delivery with low doses of the HLA-II–targeted vaccines resulted in rapid and increased Ab responses. Importantly, painless intradermal jet delivery of DNA was as effective as delivery by needle injection followed by electroporation. As an indication that the vaccines could also be useful for human application, HLA-II–targeted vaccine proteins were found to increase human CD4+ T cell responses by a factor of ×103 in vitro. Thus, targeting of Ag to MHC-II molecules may represent an attractive strategy for increasing efficacy of DNA vaccines in larger animals and humans. PMID:27671110

  20. Inhibitory effects of thymus-independent type 2 antigens on MHC class II-restricted antigen presentation: comparative analysis of carbohydrate structures and the antigen presenting cell.

    PubMed

    González-Fernández, M; Carrasco-Marín, E; Alvarez-Domínguez, C; Outschoorn, I M; Leyva-Cobián, F

    1997-02-25

    The role of thymus-independent type 2 (TI-2) antigens (polysaccharides) on the MHC-II-restricted processing of protein antigens was studied in vitro. In general, antigen presentation is inhibited when both peritoneal and splenic macrophages (M phi) as well as Küpffer cells (KC) are preincubated with acidic polysaccharides or branched dextrans. However, the inhibitory effect of neutral polysaccharides was minimal when KC were used as antigen presenting cells (APC). Morphological evaluation of the uptake of fluoresceinated polysaccharides clearly correlates with this selective and differential interference. Polysaccharides do not block MHC-I-restricted antigen presentation. Some chemical characteristics shared by different saccharides seem to be specially related to their potential inhibitory abilities: (i) those where two anomeric carbon atoms of two interlinked sugars and (ii) those containing several sulfate groups per disaccharide repeating unit. No polysaccharide being inhibitory in M phi abrogated antigen processing in other APC: lipopolysaccharide-activated B cells, B lymphoma cells, or dendritic cells (DC). Using radiolabeled polysaccharides it was observed that DC and B cells incorporated less radioactivity as a function of time than M phi. Morphological evaluation of these different APC incubated for extended periods of time with inhibitory concentrations of polysaccharides revealed intense cytoplasmic vacuolization in M phi but not in B cells or DC. The large majority of M phi lysosomes containing polysaccharides fail to fuse with incoming endocytic vesicles and delivery of fluid-phase tracers was reduced, suggesting that indigestible carbohydrates reduced the fusion of these loaded lysosomes with endosomes containing recently internalized tracers. It is suggested that the main causes of this antigen presentation blockade are (i) the chemical characteristics of certain carbohydrates and whether the specific enzymatic machinery for their intracellular

  1. SNP variants associated with non-Hodgkin lymphoma (NHL) correlate with human leukocyte antigen (HLA) class II expression.

    PubMed

    Ten, Lik-Chin; Chin, Yoon-Ming; Tai, Mei-Chee; Chin, Edmund Fui-Min; Lim, Yat-Yuen; Suthandiram, Sujatha; Chang, Kian-Meng; Ong, Tee-Chuan; Bee, Ping-Chong; Mohamed, Zahurin; Gan, Gin-Gin; Ng, Ching-Ching

    2017-01-31

    Large consortia efforts and genome-wide association studies (GWASs) have linked a number of genetic variants within the 6p21 chromosomal region to non-Hodgkin lymphoma (NHL). Complementing these efforts, we genotyped previously reported SNPs in the human leukocyte antigen (HLA) class I (rs6457327) and class II (rs9271100, rs2647012 and rs10484561) regions in a total of 1,145 subjects (567 NHL cases and 578 healthy controls) from two major ethnic groups in Malaysia, the Malays and the Chinese. We identified a NHL-associated (PNHL_add = 0.0008; ORNHL_add = 0.54; 95% CI = 0.37-0.77) and B-cell associated (PBcell_add = 0.0007; ORBcell_add = 0.51; 95% CI = 0.35-0.76) SNP rs2647012 in the Malaysian Malays. In silico cis-eQTL analysis of rs2647012 suggests potential regulatory function of nearby HLA class II molecules. Minor allele rs2647012-T is linked to higher expression of HLA-DQB1, rendering a protective effect to NHL risk. Our findings suggest that the HLA class II region plays an important role in NHL etiology.

  2. SNP variants associated with non-Hodgkin lymphoma (NHL) correlate with human leukocyte antigen (HLA) class II expression

    PubMed Central

    Ten, Lik-Chin; Chin, Yoon-Ming; Tai, Mei-Chee; Chin, Edmund Fui-Min; Lim, Yat-Yuen; Suthandiram, Sujatha; Chang, Kian-Meng; Ong, Tee-Chuan; Bee, Ping-Chong; Mohamed, Zahurin; Gan, Gin-Gin; Ng, Ching-Ching

    2017-01-01

    Large consortia efforts and genome-wide association studies (GWASs) have linked a number of genetic variants within the 6p21 chromosomal region to non-Hodgkin lymphoma (NHL). Complementing these efforts, we genotyped previously reported SNPs in the human leukocyte antigen (HLA) class I (rs6457327) and class II (rs9271100, rs2647012 and rs10484561) regions in a total of 1,145 subjects (567 NHL cases and 578 healthy controls) from two major ethnic groups in Malaysia, the Malays and the Chinese. We identified a NHL-associated (PNHL_add = 0.0008; ORNHL_add = 0.54; 95% CI = 0.37–0.77) and B-cell associated (PBcell_add = 0.0007; ORBcell_add = 0.51; 95% CI = 0.35–0.76) SNP rs2647012 in the Malaysian Malays. In silico cis-eQTL analysis of rs2647012 suggests potential regulatory function of nearby HLA class II molecules. Minor allele rs2647012-T is linked to higher expression of HLA-DQB1, rendering a protective effect to NHL risk. Our findings suggest that the HLA class II region plays an important role in NHL etiology. PMID:28139690

  3. Disruption of HLA class II antigen presentation in Burkitt lymphoma: implication of a 47,000 MW acid labile protein in CD4+ T-cell recognition.

    PubMed

    God, Jason M; Zhao, Dan; Cameron, Christine A; Amria, Shereen; Bethard, Jennifer R; Haque, Azizul

    2014-07-01

    While Burkitt lymphoma (BL) has a well-known defect in HLA class I-mediated antigen presentation, the exact role of BL-associated HLA class II in generating a poor CD4(+) T-cell response remains unresolved. Here, we found that BL cells are deficient in their ability to optimally stimulate CD4(+) T cells via the HLA class II pathway. This defect in CD4(+) T-cell recognition was not associated with low levels of co-stimulatory molecules on BL cells, as addition of external co-stimulation failed to elicit CD4(+) T-cell activation by BL. Further, the defect was not caused by faulty antigen/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Interestingly, functional class II-peptide complexes were formed at acidic pH 5·5, which restored immune recognition. Acidic buffer (pH 5·5) eluate from BL cells contained molecules that impaired class II-mediated antigen presentation and CD4(+) T-cell recognition. Biochemical analysis showed that these molecules were greater than 30,000 molecular weight in size, and proteinaceous in nature. In addition, BL was found to have decreased expression of a 47,000 molecular weight enolase-like molecule that enhances class II-mediated antigen presentation in B cells, macrophages and dendritic cells, but not in BL cells. These findings demonstrate that BL likely has multiple defects in HLA class II-mediated antigen presentation and immune recognition, which may be exploited for future immunotherapies.

  4. The class I myosin Myo1e regulates TLR4-triggered macrophage spreading, chemokine release and antigen presentation via MHC class II

    PubMed Central

    Wenzel, Jens; Ouderkirk, Jessica L.; Krendel, Mira; Lang, Roland

    2014-01-01

    TLR-mediated recognition of microbial danger induces substantial changes in macrophage migration, adherence and phagocytosis. Recently, we described the LPS-regulated phosphorylation of many cytoskeleton-associated proteins by phosphoproteomics. The functional role of these cytoskeletal and motor proteins in innate immune cell responses is largely unexplored. Here, we first identified both long-tailed class I myosins Myo1e and Myo1f as important contributors to LPS-triggered macrophage spreading. Mouse bone marrow-derived macrophages and dendritic cells (DCs) deficient in Myo1e selectively secreted increased amounts of the chemokine CCL2. In addition, the cell surface expression of MHC class II (MHC-II) on both cell types was reduced in the absence of Myo1e. However, transcriptional changes in CCL2 and MHC-II were not observed in the absence of Myo1e, indicating that Myo1e regulates specific intracellular transport processes. The capacity of macrophages and DCs lacking Myo1e to stimulate antigen-specific CD4+ T-cell proliferation was impaired, consistent with the reduced MHC-II surface protein levels. Surprisingly, in Myo1e-deficient DCs, the proteolytic cleavage of endocytosed antigen was also increased. Together, our results provide evidence for a non-redundant function of the motor protein Myo1e in the regulation of TLR4-controlled, cytoskeleton-associated functional properties of macrophages and DCs, and in induction of a full MHC-II-restricted adaptive immune response. PMID:25263281

  5. Need for tripeptidyl-peptidase II in major histocompatibility complex class I viral antigen processing when proteasomes are detrimental.

    PubMed

    Guil, Sara; Rodríguez-Castro, Marta; Aguilar, Francisco; Villasevil, Eugenia M; Antón, Luis C; Del Val, Margarita

    2006-12-29

    CD8(+) T lymphocytes recognize infected cells that display virus-derived antigenic peptides complexed with major histocompatibility complex class I molecules. Peptides are mainly byproducts of cellular protein turnover by cytosolic proteasomes. Cytosolic tripeptidyl-peptidase II (TPPII) also participates in protein degradation. Several peptidic epitopes unexpectedly do not require proteasomes, but it is unclear which proteases generate them. We studied antigen processing of influenza virus nucleoprotein epitope NP(147-155), an archetype epitope that is even destroyed by a proteasome-mediated mechanism. TPPII, with the assistance of endoplasmic reticulum trimming metallo-aminopeptidases, probably ERAAP (endoplasmic reticulum aminopeptidase associated with antigen processing), was crucial for nucleoprotein epitope generation both in the presence of functional proteasomes and when blocked by lactacystin, as shown with specific chemical inhibitors and gene silencing. Different protein contexts and subcellular targeting all allowed epitope processing by TPPII as well as trimming. The results show the plasticity of the cell's assortment of proteases for providing ligands for recognition by antiviral CD8(+) T cells. Our observations identify for the first time a set of proteases competent for antigen processing of an epitope that is susceptible to destruction by proteasomes.

  6. Disruption of HLA class II antigen presentation in Burkitt lymphoma: implication of a 47 000 MW acid labile protein in CD4+ T-cell recognition

    PubMed Central

    God, Jason M; Zhao, Dan; Cameron, Christine A; Amria, Shereen; Bethard, Jennifer R; Haque, Azizul

    2014-01-01

    While Burkitt lymphoma (BL) has a well-known defect in HLA class I-mediated antigen presentation, the exact role of BL-associated HLA class II in generating a poor CD4+ T-cell response remains unresolved. Here, we found that BL cells are deficient in their ability to optimally stimulate CD4+ T cells via the HLA class II pathway. This defect in CD4+ T-cell recognition was not associated with low levels of co-stimulatory molecules on BL cells, as addition of external co-stimulation failed to elicit CD4+ T-cell activation by BL. Further, the defect was not caused by faulty antigen/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Interestingly, functional class II–peptide complexes were formed at acidic pH 5·5, which restored immune recognition. Acidic buffer (pH 5·5) eluate from BL cells contained molecules that impaired class II-mediated antigen presentation and CD4+ T-cell recognition. Biochemical analysis showed that these molecules were greater than 30 000 molecular weight in size, and proteinaceous in nature. In addition, BL was found to have decreased expression of a 47 000 molecular weight enolase-like molecule that enhances class II-mediated antigen presentation in B cells, macrophages and dendritic cells, but not in BL cells. These findings demonstrate that BL likely has multiple defects in HLA class II-mediated antigen presentation and immune recognition, which may be exploited for future immunotherapies. PMID:24628049

  7. Human-leukocyte antigen class II genes in early-onset obsessive-compulsive disorder.

    PubMed

    Rodriguez, Natalia; Morer, Astrid; González-Navarro, E Azucena; Gassó, Patricia; Boloc, Daniel; Serra-Pagès, Carles; Lafuente, Amalia; Lazaro, Luisa; Mas, Sergi

    2017-05-31

    The exact aetiology of obsessive-compulsive disorder (OCD) is unknown, although there is evidence to suggest a gene-environment interaction model. Several lines of evidence support a possible role of the immune system in this model. The present study explores the allele variability in HLA genes of class II (HLA-DRB1, HLA-DQB1) in a sample of 144 early-onset OCD compared with reference samples of general population in the same geographical area. None of the 39 alleles identified (allele frequency >1%) showed significant differences between OCD and reference populations. Pooling the different alleles that comprised HLA-DR4 (including DRB1*04:01, DRB1*04:04 and DRB1*04:05 alleles) we observed a significantly higher frequency (X(2)1 = 5.53, P = 0.018; OR = 1.64, 95% CI 1.08-2.48) of these alleles in the early-onset OCD sample (10.8%) than in the reference population (6.8%). Taking into account the role of HLA class II genes in the central nervous system, the results presented here support a role of the immune system in the pathophysiological model of OCD.

  8. Allele and haplotype frequencies at human leukocyte antigen class I and II genes in Venezuela's population.

    PubMed

    Del Pilar Fortes, María; Gill, Gisselle; Paredes, María Elena; Gamez, Ligia Elena; Palacios, Marina; Blanca, Isaac; Tassinari, Paolo

    2012-01-01

    Population studies represent an integral part and link in understanding the complex chain of host-pathogen interactions, disease pathogenesis, and MHC gene polymorphisms. Genes of Mongoloid, Caucasoid, and Negroid populations have created a distinctive HLA genetic profile in the Venezuelan population. Our objective was to determine the predominant HLA class I and II alleles and haplotype frequencies in the hybrid population of Venezuela. The study population consisted of 486 healthy unrelated native Venezuelans and 180 families. We examined the frequency of HLA A-B-C, HLA-DQ and HLA-DR genes by polymerase chain reaction and subsequent hybridization with sequence-specific oligonucleotide probes. Phenotypic, allelic and haplotype frequencies were estimated by direct counting and using the maximum-likelihood method. The predominant HLA class I alleles were A*02, A*24, A*68, B*35, B*44, B*51, B*07, B*15 and Cw*07. Regarding HLA class II, the most frequent alleles were DQB1*03 and DRB1*04, DRB1*15, DRB1*13, DRB1*07. The prevailing haplotype was HLA-A*02B*35 DQB1*03 DRB1*04. Some of these alleles and haplotype frequencies were predominantly present in Amerindians (A*02, A*24, B*35, Cw*07, DRB1*04, A*24 B*35). Previous reports have shown high incidence of A*02, B*44, B*51, DRB1*15, DRB1*13, DRB1*07 alleles in several European populations and A*68, B*07, B*15 alleles in African Americans, which could have contributed to the ethnic admixture of the Venezuelan population. We conclude that our results provide strong evidence that Venezuela's population represents an admixture of the primitive Mongoloid Aborigines, Caucasoid Europeans and Western African Negroid migrants.

  9. Processing and MHC class II presentation of exogenous soluble antigen involving a proteasome-dependent cytosolic pathway in CD40-activated B cells.

    PubMed

    Becker, Hans Jiro; Kondo, Eisei; Shimabukuro-Vornhagen, Alexander; Theurich, Sebastian; von Bergwelt-Baildon, Michael S

    2016-08-01

    Activated B cells have the capacity to present antigen and induce immune responses as potent antigen-presenting cells (APCs). As in other APCs, antigen presentation by B cells involves antigen internalization, antigen processing, and peptide loading onto MHC molecules. However, while the mechanism of antigen processing has been studied extensively in other APCs, this pathway remains elusive in B cells. The aim of this study was to investigate the MHC class II processing pathway in CD40-activated B cells (CD40Bs), as a model for activated, antigen-presenting B cells. Using CMV pp65 as a model antigen, we evaluated processing and presentation of the CD4 + T-cell epitope 509-523 (K509) by human CD40Bs in ELISPOT assays. As expected, stimulation of specific CD4 + T-cell clones was attenuated after pretreatment of CD40Bs with inhibitors of classic class II pathway components. However, proteasome inhibitors such as epoxomicin limited antigen presentation as well. This suggests that the antigen is processed in a non-classical, cytosolic MHC class II pathway. Further experiments with truncated protein variants revealed involvement of the proteasome in processing of the N and C extensions of the epitope. Access to the cytosol was shown to be size dependent. Epoxomicin sensitivity exclusively in CD40B cells, but not in dendritic cells, suggests a novel processing mechanism unique to this APC. Our data suggest that B cells process antigen using a distinct, non-classical class II pathway.

  10. Direct binding of a myasthenia gravis related epitope to MHC class II molecules on living murine antigen-presenting cells.

    PubMed Central

    Mozes, E; Dayan, M; Zisman, E; Brocke, S; Licht, A; Pecht, I

    1989-01-01

    MHC gene products present antigenic epitopes to the antigen receptor on T cells. Nevertheless, direct binding of such epitopes to MHC class II proteins on normal living antigen-presenting cells (APCs) has not yet been demonstrated. We have previously shown a significant difference in the ability of T cells of myasthenia gravis (MG) patients to proliferate in response to the synthetic peptide p195-212 of the human acetylcholine receptor (AChR) alpha-subunit in comparison to healthy controls. The observed proliferative responses correlated significantly with HLA-DR5. Moreover, lymph node cells of various mouse strains that were primed with the T cell epitope, p195-212, were found to proliferate to different extents. To investigate these observations further, we designed an assay for direct binding of p195-212 to MHC class II proteins on the surface of freshly prepared splenic adherent cells. Binding of a biotinylated p195-212 was monitored using phycoerythrin-avidin by flow cytometry. Fifteen to sixty per cent of the cells were labeled following incubation with the biotinylated peptide. Binding was observed only to splenic adherent cells derived from mouse strains of which T cells were capable of proliferating in response to p195-212. The binding specificity, in terms of epitope structure and its site of interaction on the cells, was shown by its inhibition with an excess of the unlabeled peptide or with the relevant monoclonal anti-I-A antibodies. These results constitute the first direct evidence for the specific binding of a T cell epitope to live APC. PMID:2480232

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

    PubMed

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

    2013-04-26

    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.

  12. Mouse γδ T cells are capable of expressing MHC class II molecules, and of functioning as antigen-presenting cells⋆

    PubMed Central

    Cheng, Lan; Cui, Yan; Shao, Hui; Han, Gencheng; Zhu, Ling; Huang, Yafei; O'Brien, Rebecca L.; Born, Willi K.; Kaplan, Henry J.; Sun, Deming

    2008-01-01

    Although human and bovine γδ T cells were shown to express MHC class II antigen and function as APCs, attempts to determine if mouse γδ T cells have similar functions remained unsuccessful. We now show that γδ T cells derived from immunized mice also can be induced to express MHC class II and co-stimulatory molecules after activation in vitro, and are capable of antigen presentation. Using highly purified γδ T cells, we found that, unlike human γδ T cells, the expression of MHC class II molecules by mouse γδ T cells is limited to newly activated cells. Highest levels of MHC class II expression were seen on activated γδ T cells that had lost most surface-expressed γδ TCR while exhibiting increased levels of intracellular γδ TCR. In the absence of further stimulation, MHC class II expression gradually declined with the γδ T cells regaining their surface TCR. We also show that cytokine-activated γδ T cells can also express MHC class II antigen and exercise antigen-presenting activity. PMID:18774183

  13. HLA class II tetramers: tools for direct analysis of antigen-specific CD4+ T cells.

    PubMed

    Nepom, Gerald T; Buckner, Jane H; Novak, Erik J; Reichstetter, Sandra; Reijonen, Helena; Gebe, John; Wang, Rongfang; Swanson, Eric; Kwok, William W

    2002-01-01

    Immunotherapies for human autoimmune and immune-mediated diseases are proliferating rapidly, and with these changes comes the opportunity to monitor patients for immune responses to therapy based on early surrogate markers for clinical responses. Class II tetramers have the potential to serve as these sorts of markers for immune monitoring, and thereby assist with patient management, therapy selection, and improved outcomes. However, important issues of TCR avidity require resolution, because much is still unknown regarding location, quantitation, and characterization of the human T cell response. Opportunities for application of tetramer technologies in the near future will enable both clinical progress and the development of new insights into human CD4+ T cell biology in vivo.

  14. Up-regulation of major histocompatibility complex class II antigen expression in the central nervous system of dogs with spontaneous canine distemper virus encephalitis.

    PubMed

    Alldinger, S; Wünschmann, A; Baumgärtner, W; Voss, C; Kremmer, E

    1996-09-01

    Major histocompatibility complex class II (MHC II) and canine distemper virus (CDV) antigen expression were compared by immunohistochemistry in the cerebellar white matter of ten dogs with naturally occurring canine distemper encephalitis. In addition, infiltrating mononuclear cells were characterized by employing poly- and monoclonal antibodies directed against human CD3, canine MHC II, CD5, B cell antigen and CDV-specific nucleoprotein. Positive antigen-antibody reaction was visualized by the avidin-biotin-peroxidase complex method on frozen sections. Histologically, neuropathological changes were categorized into acute, subacute, and chronic. In control brains, MHC II expression was weak and predominantly detected on resident microglia of the white matter and on endothelial, perivascular and intravascular cells. In CDV antigen-positive brains, MHC II was mainly found on microglia and to a lesser extent on endothelial, meningeal, choroid plexus epithelial, ependymal and intravascular cells. In addition, virtually all of the perivascular cells expressed MHC II antigen. CDV antigen was demonstrated most frequently in astrocytes. Of the perivascular lymphocytes, the majority were CD3-positive cells, followed by B cells. Only a small proportion of perivascular cells expressed the CD5 antigen. In addition, B cells and CD3 and CD5 antigen-positive cells were found occasionally in subacute and frequently in chronic demyelinating plaques. In acute encephalitis, CDV antigen exhibited a multifocal or diffuse distribution, and MHC II was moderately up-regulated throughout the white matter and accentuated in CDV antigen-positive plaques. In subacute encephalitis, moderate multifocal CDV antigen and moderate to strong diffuse MHC II-specific staining, especially prominent in CDV antigen-positive lesions, were observed. In chronic encephalitis, CDV antigen expression was restricted to single astrocytes at the edge of the lesions or was absent, while MHC II expression

  15. The Ia.2 Epitope Defines a Subset of Lipid Raft Resident MHC Class II Molecules Crucial to Effective Antigen Presentation1

    PubMed Central

    Busman-Sahay, Kathleen; Sargent, Elizabeth; Harton, Jonathan A.; Drake, James R.

    2016-01-01

    Previous work has established that binding of the 11-5.2 anti-I-Ak mAb, which recognizes the Ia.2 epitope on I-Ak class II molecules, elicits MHC class II signaling, whereas binding of two other anti-I-Ak mAb that recognize the Ia.17 epitope fail to elicit signaling. Using a biochemical approach, we establish that the Ia.2 epitope recognized by the widely used 11-5.2 mAb defines a subset of cell surface I-Ak molecules predominantly found within membrane lipid rafts. Functional studies demonstrate that the Ia.2 bearing subset of I-Ak class II molecules is critically necessary for effective B cell–T cell interactions especially at low antigen doses, a finding consistent with published studies on the role of raft-resident class II molecules in CD4 T cell activation. Interestingly, B cells expressing recombinant I-Ak class II molecules possessing a β chain-tethered HEL peptide lack the Ia.2 epitope and fail to partition into lipid rafts. Moreover, cells expressing Ia.2 negative tethered peptide-class II molecules are severely impaired in their ability to present both tethered peptide or peptide derived from exogenous antigen to CD4 T cells. These results establish the Ia.2 epitope as defining a lipid raft-resident MHC class II confomer vital to the initiation of MHC class II restricted B cell–T cell interactions. PMID:21543648

  16. Effect of oestradiol and pathogen-associated molecular patterns on class II-mediated antigen presentation and immunomodulatory molecule expression in the mouse female reproductive tract

    PubMed Central

    Ochiel, Daniel O; Rossoll, Richard M; Schaefer, Todd M; Wira, Charles R

    2012-01-01

    Cells of the female reproductive tract (FRT) can present antigen to naive and memory T cells. However, the effects of oestrogen, known to modulate immune responses, on antigen presentation in the FRT remain undefined. In the present study, DO11.10 T-cell antigen receptor transgenic mice specific for the class II MHC-restricted ovalbumin (OVA) 323–339 peptide were used to study the effects of oestradiol and pathogen-associated molecular patterns on antigen presentation in the FRT. We report here that oestradiol inhibited antigen presentation of OVA by uterine epithelial cells, uterine stromal cells and vaginal cells to OVA-specific memory T cells. When ovariectomized animals were treated with oestradiol for 1 or 3 days, antigen presentation was decreased by 20–80%. In contrast, incubation with PAMP increased antigen presentation by epithelial cells (Pam3Cys), stromal cells (peptidoglycan, Pam3Cys) and vaginal cells (Pam3Cys). In contrast, CpG inhibited both stromal and vaginal cell antigen presentation. Analysis of mRNA expression by reverse transcription PCR indicated that oestradiol inhibited CD40, CD80 and class II in the uterus and CD40, CD86 and class II in the vagina. Expression in isolated uterine and vaginal cells paralleled that seen in whole tissues. In contrast, oestradiol increased polymeric immunoglobulin receptor mRNA expression in the uterus and decreased it in the vagina. These results indicate that antigen-presenting cells in the uterus and vagina are responsive to oestradiol, which inhibits antigen presentation and co-stimulatory molecule expression. Further, these findings suggest that antigen-presenting cells in the uterus and vagina respond to selected Toll-like receptor agonists with altered antigen presentation. PMID:22043860

  17. Cloning and sequence analysis of a gene encoding a 67-kilodalton myosin-cross-reactive antigen of Streptococcus pyogenes reveals its similarity with class II major histocompatibility antigens.

    PubMed Central

    Kil, K S; Cunningham, M W; Barnett, L A

    1994-01-01

    The group A streptococcal sequela acute rheumatic fever (ARF) has been associated with immunological cross-reactivity between streptococcal and heart proteins. To identify Streptococcus pyogenes genes that encode a myosin cross-reactive antigen(s) recognized by ARF sera, a genomic library from an emm deletion strain (T28/51/4) was screened with a single ARF serum. A positively identified lambda EMBL3 clone (T.2.18) produced a protein which reacted with myosin-specific antibodies affinity purified from individual ARF sera. The recombinant protein was initially estimated to be 60 kDa in size by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; however, upon sequence analysis it had a molecular mass equivalent to 67 kDa. Sera from patients with streptococcal infections, acute glomerulonephritis, and ARF were reactive with the recombinant 67-kDa protein. However, individual sera from healthy persons were negative or demonstrated low levels of reactivity with the 67-kDa antigen. The gene encoding the 67-kDa myosin-cross-reactive antigen was subcloned, and its nucleotide sequence was determined by using a combined strategy of DNA sequencing of the cloned gene and N-terminal amino acid sequencing of the protein expressed in Escherichia coli. The amino-terminal sequence deduced from the nucleotide sequence of an open reading frame was identical to that determined from the 67-kDa protein expressed in E. coli. The gene encoded 590 amino acids with a calculated molecular weight of 67,381. No cleavable signal peptide was detected with the 67-kDa protein expressed in E. coli. The deduced amino acid sequence of the 67-kDa protein did not exhibit significant similarity to any known streptococcal proteins. However, it was found to be 19% identical and 62% similar over 151 amino acid residues to the beta chain of mouse major histocompatibility complex class II antigen (I-Au). Similar degrees of homology to the beta chains of other murine and human class II haplotypes were

  18. Endosomally stored MHC class II does not contribute to antigen presentation by dendritic cells at inflammatory conditions.

    PubMed

    ten Broeke, Toine; van Niel, Guillaume; Wauben, Marca H M; Wubbolts, Richard; Stoorvogel, Willem

    2011-08-01

    Major histocompatibility complex (MHC) class II (MHCII) is constitutively expressed by immature dendritic cells (DC), but has a short half-life as a consequence of its transport to and degradation in lysosomes. For its transfer to lysosomes, MHCII is actively sorted to the intraluminal vesicles (ILV) of multivesicular bodies (MVB), a process driven by its ubiquitination. ILV have, besides their role as an intermediate compartment in lysosomal transfer, also been proposed to function as a site for MHCII antigen loading and temporal storage. In that scenario, DC would recruit antigen-loaded MHCII to the cell surface in response to a maturation stimulus by allowing ILV to fuse back with the MVB delimiting membrane. Other studies, however, explained the increase in cell surface expression during DC maturation by transient upregulation of MHCII synthesis and reduced sorting of newly synthesized MHCII to lysosomes. Here, we have characterized the relative contributions from the biosynthetic and endocytic pathways and found that the vast majority of antigen-loaded MHCII that is stably expressed at the plasma membrane by mature DC is synthesized after exposure to inflammatory stimuli. Pre-existing endosomal MHCII contributed only when it was not yet sorted to ILV at the moment of DC activation. Together with previous records, our current data are consistent with a model in which passage of MHCII through ILV is not required for antigen loading in maturing DC and in which sorting to ILV in immature DC provides a one-way ticket for lysosomal degradation. © 2011 John Wiley & Sons A/S.

  19. Class II major histocompatibility complex mutant mice to study the germ-line bias of T-cell antigen receptors

    PubMed Central

    Silberman, Daniel; Krovi, Sai Harsha; Tuttle, Kathryn D.; Crooks, James; Reisdorph, Richard; White, Janice; Gross, James; Matsuda, Jennifer L.; Gapin, Laurent; Marrack, Philippa; Kappler, John W.

    2016-01-01

    The interaction of αβ T-cell antigen receptors (TCRs) with peptides bound to MHC molecules lies at the center of adaptive immunity. Whether TCRs have evolved to react with MHC or, instead, processes in the thymus involving coreceptors and other molecules select MHC-specific TCRs de novo from a random repertoire is a longstanding immunological question. Here, using nuclease-targeted mutagenesis, we address this question in vivo by generating three independent lines of knockin mice with single-amino acid mutations of conserved class II MHC amino acids that often are involved in interactions with the germ-line–encoded portions of TCRs. Although the TCR repertoire generated in these mutants is similar in size and diversity to that in WT mice, the evolutionary bias of TCRs for MHC is suggested by a shift and preferential use of some TCR subfamilies over others in mice expressing the mutant class II MHCs. Furthermore, T cells educated on these mutant MHC molecules are alloreactive to each other and to WT cells, and vice versa, suggesting strong functional differences among these repertoires. Taken together, these results highlight both the flexibility of thymic selection and the evolutionary bias of TCRs for MHC. PMID:27588903

  20. Class II major histocompatibility complex mutant mice to study the germ-line bias of T-cell antigen receptors.

    PubMed

    Silberman, Daniel; Krovi, Sai Harsha; Tuttle, Kathryn D; Crooks, James; Reisdorph, Richard; White, Janice; Gross, James; Matsuda, Jennifer L; Gapin, Laurent; Marrack, Philippa; Kappler, John W

    2016-09-20

    The interaction of αβ T-cell antigen receptors (TCRs) with peptides bound to MHC molecules lies at the center of adaptive immunity. Whether TCRs have evolved to react with MHC or, instead, processes in the thymus involving coreceptors and other molecules select MHC-specific TCRs de novo from a random repertoire is a longstanding immunological question. Here, using nuclease-targeted mutagenesis, we address this question in vivo by generating three independent lines of knockin mice with single-amino acid mutations of conserved class II MHC amino acids that often are involved in interactions with the germ-line-encoded portions of TCRs. Although the TCR repertoire generated in these mutants is similar in size and diversity to that in WT mice, the evolutionary bias of TCRs for MHC is suggested by a shift and preferential use of some TCR subfamilies over others in mice expressing the mutant class II MHCs. Furthermore, T cells educated on these mutant MHC molecules are alloreactive to each other and to WT cells, and vice versa, suggesting strong functional differences among these repertoires. Taken together, these results highlight both the flexibility of thymic selection and the evolutionary bias of TCRs for MHC.

  1. Alternative endogenous protein processing via an autophagy-dependent pathway compensates for Yersinia-mediated inhibition of endosomal major histocompatibility complex class II antigen presentation.

    PubMed

    Rüssmann, Holger; Panthel, Klaus; Köhn, Brigitte; Jellbauer, Stefan; Winter, Sebastian E; Garbom, Sara; Wolf-Watz, Hans; Hoffmann, Sigrid; Grauling-Halama, Silke; Geginat, Gernot

    2010-12-01

    Extracellular Yersinia pseudotuberculosis employs a type III secretion system (T3SS) for translocating virulence factors (Yersinia outer proteins [Yops]) directly into the cytosol of eukaryotic cells. Recently, we used YopE as a carrier molecule for T3SS-dependent secretion and translocation of listeriolysin O (LLO) from Listeria monocytogenes. We demonstrated that translocation of chimeric YopE/LLO into the cytosol of macrophages by Yersinia results in the induction of a codominant antigen-specific CD4 and CD8 T-cell response in orally immunized mice. In this study, we addressed the requirements for processing and major histocompatibility complex (MHC) class II presentation of chimeric YopE proteins translocated into the cytosol of macrophages by the Yersinia T3SS. Our data demonstrate the ability of Yersinia to counteract exogenous MHC class II antigen presentation of secreted hybrid YopE by the action of wild-type YopE and YopH. In the absence of exogenous MHC class II antigen presentation, an alternative pathway was identified for YopE fusion proteins originating in the cytosol. This endogenous antigen-processing pathway was sensitive to inhibitors of phagolysosomal acidification and macroautophagy, but it did not require the function either of the proteasome or of transporters associated with antigen processing. Thus, by an autophagy-dependent mechanism, macrophages are able to compensate for the YopE/YopH-mediated inhibition of the endosomal MHC class II antigen presentation pathway for exogenous antigens. This is the first report demonstrating that autophagy might enable the host to mount an MHC class II-restricted CD4 T-cell response against translocated bacterial virulence factors. We provide critical new insights into the interaction between the mammalian immune system and a human pathogen.

  2. DMA and DMB are the only genes in the class II region of the human MHC needed for class II-associated antigen processing

    SciTech Connect

    Ceman, S.; Rudersdorf, R.A.; Petersen, J.M.

    1995-03-15

    Previous studies have shown that homozygous mutations between the LMP2 and DNA loci in the human MHC cause class II molecules to be abnormally conformed and unstable in the presence of SDS at low temperature, and impede class II-associated Ag processing and presentation. These abnormalities result from impaired ability to form intracellular class II/peptide complexes that predominate in normal cells. We show in this work that this defect results from deficient expression of either the DMA or the DMB gene. Human B-LCL.174 (DR3) cells, which have a deletion of all known expressible genes in the class II region, express transgene-encoded HLA-DR3, but have the abnormalities. Transfer of cosmid HA14, which contains the DMA and DMB genes, into .174 (DR3) cells restored normal DR3 conformation, stability in 0.4% SDS at 0{degrees}, and ability to process and present tetanus toxoid, but only when both DMA and DMB mRNAs were present. The requirement for both genetic expressions in engendering normal phenotypes was confirmed by transferring the cloned genes into .174 (DR3) cells separately or together. Because normal phenotypes were fully restored in transferent cells expressing DMA plus DMB, other genes in the {approximately} 1-mb homozygous class II region deletion in .174 (DR3) cells either do not participate in or are dispensable for apparently normal production of intracellular class II/peptide complexes. The properties of DM-deficient EBV-transformed B lymphoblastoid cell lines (LCLs) suggest ways of identifying humans in whom DM deficiency contributes to congenital immunodeficiency and malignancy. 67 refs., 5 figs., 1 tab.

  3. Assembly and intracellular transport of HLA-DM and correction of the class II antigen-processing defect in T2 cells.

    PubMed

    Denzin, L K; Robbins, N F; Carboy-Newcomb, C; Cresswell, P

    1994-10-01

    MHC class II molecules expressed in T2 cells fail to acquire a normal complement of endocytically generated peptides. The defect is repaired by introducing HLA-DMA and HLA-DMB cDNA expression vectors, determined by the restoration of SDS stability of class II alpha beta dimers, restoration of a normal conformation for HLA-DR3 as detected by a monoclonal antibody, and by a reduction in class II-associated invariant chain peptides. The intracellular distribution of class II and invariant chain molecules is also restored to that of wild-type cells. The HLA-DMA and HLA-DMB products appear to form a heterodimer that, although transported at least to the medial Golgi, is not expressed at the cell surface. These findings are consistent with HLA-DM functioning intracellularly to facilitate class II-restricted antigen processing.

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

    USDA-ARS?s Scientific Manuscript database

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

  5. Functional expression of a cattle MHC class II DR-like antigen on mouse L cells

    SciTech Connect

    Fraser, D.C.; Craigmile, S.; Campbell, J.D.M.

    1996-09-01

    Cattle DRA and DRB genes, cloned by reverse-transcription polymerase chain reaction, were transfected into mouse L cells. The cattle DR-expressing L-cell transfectant generated was analyzed serologically, biochemically, and functionally. Sequence analysis of the transfected DRB gene clearly showed showed that it was DRB3 allele DRB3*0101, which corresponds to the 1D-IEF-determined allele DRBF3. 1D-IEF analysis of the tranfectant confirmed that the expressed DR product was DRBF3. Functional integrity of the transfected gene products was demonstrated by the ability of the transfectant cell line to present two antigens (the foot-and-mouth disease virus-derived peptide FMDV15, and ovalbumin) to antigen-specific CD4{sup +} T cells from both the original animal used to obtain the genes, and also from an unrelated DRBF3{sup +} heterozygous animal. Such transfectants will be invaluable tools, allowing us to dissect the precise contributions each locus product makes to the overall immune response in heterozygous animals, information essential for rational vaccine design. 45 refs., 5 figs., 1 tab.

  6. Association of a dog leukocyte antigen class II haplotype with hypoadrenocorticism in Nova Scotia Duck Tolling Retrievers.

    PubMed

    Hughes, A M; Jokinen, P; Bannasch, D L; Lohi, H; Oberbauer, A M

    2010-06-01

    Canine hypoadrenocorticism (Addison's disease) is due to a deficiency of corticosteroids and mineralocorticoids produced by the adrenals. Although this is a relatively uncommon disease in the general dog population, some breeds, including the Nova Scotia Duck Tolling Retriever (NSDTR), are at increased risk for developing hypoadrenocorticism. A prior study has shown that the increased risk is due to a heritable component. This potentially lethal disorder is hypothesized to have an autoimmune etiology, thus the aim of this study was to determine whether genetic susceptibility to hypoadrenocorticism in NSDTRs is associated with genes of the canine major histocompatibility complex [MHC; dog leukocyte antigen system (DLA)]. Samples were collected from NSDTRs diagnosed with hypoadrenocorticism and healthy siblings or country-matched controls. The DLA class II alleles and haplotypes were determined and compared between cases and controls. We found seven different haplotypes of which the haplotype DLA-DRB1*01502/DQA*00601/DQB1*02301 was significantly more prevalent in the diseased dogs (P = 0.044). In addition, these affected dogs also were more likely to be homozygous across the DLA class II region than the control dogs (OR = 6.7, CI = 1.5-29.3, P = 0.011). We also found that homozygous dogs, regardless of their haplotype, tended to have earlier disease onset compared with heterozygous dogs. These data indicate a limited MHC diversity in North American NSDTRs and suggest that the MHC may play a role in the development of hypoadrenocorticism in the NSDTR, supporting the autoimmune origin of the disease.

  7. Lacking prognostic significance of beta 2-microglobulin, MHC class I and class II antigen expression in breast carcinomas.

    PubMed Central

    Wintzer, H. O.; Benzing, M.; von Kleist, S.

    1990-01-01

    To evaluate the impact of MHC antigen expression on the survival of patients with cancer, 77 human breast carcinomas were investigated for the expression of beta 2-microglobulin (beta 2m), HLA-A,B,C and HLA-DR. Thirty-one benign breast tumours were stained for comparison. The results for the carcinomas were related to the survival data of the cancer patients. The expression of beta 2m, HLA-A,B,C and HLA-DR was significantly lower in malignant tumours compared to the benign lesions. Whereas all benign tumours were positive for beta 2m and HLA-A,B,C and 28/31 positive for HLA-DR the following positivity rates were found in carcinomas: 74/77 for beta 2m, 57/77 for HLA-A,B,C and 10/77 for HLA-DR. The follow-up (median 45 months) of 66 cancer patients for overall survival and of 65 patients for disease-free survival revealed no influence of beta 2m, HLA-A,B,C or HLA-DR expression on the prognosis of this cancer. In conclusion, experimental data indicating the importance of MHC antigens in anti-tumour responses are not confirmed by the analysis of cancer patient survival data. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2201398

  8. Expression of HLA-DR antigen in human class II mutant B-cell lines by double infection with retrovirus vectors

    SciTech Connect

    Yang, Z.; Korman, A.J.; Cooper, J.; Pious, D.; Accolla, R.S.; Mulligan, R.C.; Strominger, J.L.

    1987-11-01

    A new retrovirus vector containing the gene for hygromycin B resistance (hyg) as a selectable marker under the control of an internal simian virus 40 promoter was constructed. It was used, together with an analogous previously described vector, DO1, which contains the gene for G418 resistance, to introduce and express the genes for the two chains of a human class II major histocompatibility complex antigen in NIH 3T3 cells. In addition, these vectors were used to express DR antigens in two human mutant B-lymphoblastoid cell lines, one of which was deleted for both alleles of the DR..cap alpha.. gene and the other of which expressed no class II antigens because of a genetic defect in a putative trans-acting regulatory factor.

  9. Anti-TNF monoclonal antibodies prevent haemorrhage-induced suppression of Kupffer cell antigen presentation and MHC class II antigen expression.

    PubMed Central

    Ertel, W; Morrison, M H; Ayala, A; Perrin, M M; Chaudry, I H

    1991-01-01

    Kupffer cells (KC), by virtue of their ability to present antigen (AP) and express major histocompatibility complex (MHC) class II antigen (Ia), play a pivotal role in the host defence system against invading micro-organisms. Although haemorrhagic shock depresses the above KC functions, it is not known whether increased KC tumour necrosis factor (TNF) production and elevated TNF plasma levels following haemorrhage are responsible for it. To study this, C3H/HeN mice were pretreated intraperitoneally with either anti-murine TNF antibody (anti-TNF Ab) or saline. Twenty hours later mice were bled and maintained at a mean blood pressure of 35 mmHg for 60 min followed by adequate fluid resuscitation. Two and 24 hr later, plasma was collected and KC were isolated. AP was measured by co-culturing KC with the D10.G4.1 Th cell clone. Ia expression was determined by direct immunofluorescence. Interleukin (IL)-1, IL-6 and TNF levels in KC supernatants and plasma were measured with bioassays or ELISA. Haemorrhage increased circulating TNF levels by 215% at 2 hr and by 76% at 24 hr (P less than 0.05), which was prevented by pretreatment with anti-TNF Ab. Haemorrhage-induced increase of circulating IL-6 was abolished (P less than 0.05) at 2 hr but not at 24 hr in the anti-TNF Ab group. The suppression of KC AP (P less than 0.05) and Ia expression (P less than 0.05) due to haemorrhage was attenuated (P less than 0.05) in anti-TNF Ab-treated mice at 2 and 24 hr and KC IL-1 and TNF synthesis was further (P less than 0.01) increased. These results indicate that TNF plays a critical role in the initiation and regulation of KC AP, Ia expression, and cytokine production following haemorrhage. PMID:1748476

  10. Class II human leucocyte antigen DRB1*11 in hairy cell leukaemia patients with and without haemolytic uraemic syndrome.

    PubMed

    Arons, Evgeny; Adams, Sharon; Venzon, David J; Pastan, Ira; Kreitman, Robert J

    2014-09-01

    Frequencies of human leucocyte antigens (HLA) were determined in 287 classic hairy cell leukaemia (HCL) patients. With respect to both population (n = 287) and allele (2n = 574) frequency respectively, the most common HLA class I and II antigens expressed were HLA-A*02 (49·1% and 28·6%), HLA-B*07 (21·3% and 11·1%), HLA-C*07 (46·7 and 28·2%), HLA-DQB1*03 (62·7% and 37·3%), HLA-DRB1*11 (30·0% and 16·0%) and HLA-DRB4*01 (45·3% and 29·6%). In comparing 6-14 databases of control Caucasians to 267 Caucasian HCL patients, only HLA-DRB1*11 was consistently over-represented in HCL, 31·1% of patients vs. 17-19·9% of controls (P = 0·0055 to <0·0001) and 16·5% of alleles vs. 6·5-12·3% of control alleles (P = 0·022 to <0·0001). HLA-DRB1*11 is a known risk factor for acquired thrombotic microangiopathy. Anti-CD22 recombinant immunotoxin BL22 in HCL was associated with a 12% incidence of completely reversible grade 3-4 haemolytic uraemic syndrome (HUS), mainly during the second or third retreatment cycle. Of 49 HCL patients receiving ≥2 cycles of BL22, 7 (14%) had HUS and HLA-DRB1*11 was expressed in 71% of 7 with HUS compared with only 21% of 42 without (P = 0·015). These data suggest that DBR1*11 may be a marker for increased susceptibility to HCL and, among HCL patients, could be a risk factor for BL22-induced HUS. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  11. Class II human leucocyte antigen DRB1*11 in hairy cell leukaemia patients with and without haemolytic uraemic syndrome

    PubMed Central

    Arons, Evgeny; Adams, Sharon; Venzon, Venzon, David J; Pastan, Ira; Kreitman, Robert J.

    2014-01-01

    Frequencies of human leucocyte antigens (HLA) were determined in 287 classic hairy cell leukaemia (HCL) patients. With respect to both population (n=287) and allele (2n=574) frequency, respectively, the most common HLA class I and II antigens expressed were HLA-A*02 (49.1% and 28.6%), HLA-B*07 (21.3% and 11.1%), HLA-C*07 (46.7 and 28.2%), HLA-DQB1*03 (62.7% and 37.3%), HLA-DRB1*11 (30.0% and 16.0%) and HLA-DRB4*01 (45.3% and 29.6%). In comparing 6–14 databases of control Caucasians to 267 Caucasian HCL patients, only HLA-DRB1*11 was consistently over-represented in HCL, 31.1% of patients vs 17–19.9% of controls (p=0.0055 to <0.0001) and 16.5% of alleles vs 6.5–12.3% of control alleles (p=0.022 to <0.0001). HLA-DRB1*11 is a known risk factor for acquired thrombotic microangiopathy. Anti-CD22 recombinant immunotoxin BL22 in HCL was associated with a 12% incidence of completely reversible grade 3–4 haemolytic uraemic syndrome (HUS), mainly during the second or third retreatment cycle. Of 49 HCL patients receiving ≥2 cycles of BL22, 7 (14%) had HUS and HLA-DRB1*11 was expressed in 71% of 7 with HUS compared with only 21% of 42 without (p=0.015). These data suggest that DBR1*11 may be a marker for increased susceptibility to HCL and, among HCL patients, could be a risk factor for BL22-induced HUS. PMID:24931452

  12. Non-classical antigen processing pathways are required for MHC class II-restricted direct tumor recognition by NY-ESO-1-specific CD4+ T cells

    PubMed Central

    Matsuzaki, Junko; Tsuji, Takemasa; Luescher, Immanuel; Old, Lloyd J.; Shrikant, Protul; Gnjatic, Sacha; Odunsi, Kunle

    2014-01-01

    Tumor antigen-specific CD4+ T cells that directly recognize cancer cells are important for orchestrating antitumor immune responses at the local tumor sites. However, the mechanisms of direct MHC class II (MHC-II) presentation of intracellular tumor antigen by cancer cells are poorly understood. We found that two functionally distinct subsets of CD4+ T cells were expanded after HLA-DPB1*04 (DP04)-binding NY-ESO-1157–170 peptide vaccination in ovarian cancer patients. While both subsets similarly recognized exogenous NY-ESO-1 protein pulsed on DP04+ target cells, only one type recognized target cells with intracellular expression of NY-ESO-1. The tumor-recognizing CD4+ T cells more efficiently recognized the short 8–9-mer peptides than the non-tumor-recognizing CD4+ T cells. In addition to endosomal/lysosomal proteases that are typically involved in MHC-II antigen presentation, several pathways in the MHC class I presentation pathways such as the proteasomal degradation and transporter-associated with antigen-processing (TAP)-mediated peptide transport were also involved in the presentation of intracellular NY-ESO-1 on MHC-II. The presentation was inhibited significantly by primaquine, a small molecule that inhibits endosomal recycling, consistent with findings that pharmacological inhibition of new protein synthesis enhances antigen presentation. Together, our data demonstrated that cancer cells selectively present peptides from intracellular tumor antigens on MHC-II by multiple non-classical antigen-processing pathways. Harnessing direct tumor-recognizing ability of CD4+ T cells could be a promising strategy to enhance antitumor immune responses in the immunosuppressive tumor microenvironment. PMID:24764581

  13. Nonclassical antigen-processing pathways are required for MHC class II-restricted direct tumor recognition by NY-ESO-1-specific CD4(+) T cells.

    PubMed

    Matsuzaki, Junko; Tsuji, Takemasa; Luescher, Immanuel; Old, Lloyd J; Shrikant, Protul; Gnjatic, Sacha; Odunsi, Kunle

    2014-04-01

    Tumor antigen-specific CD4(+) T cells that directly recognize cancer cells are important for orchestrating antitumor immune responses at the local tumor sites. However, the mechanisms of direct MHC class II (MHC-II) presentation of intracellular tumor antigen by cancer cells are poorly understood. We found that two functionally distinct subsets of CD4(+) T cells were expanded after HLA-DPB1*04 (DP04)-binding NY-ESO-1157-170 peptide vaccination in patients with ovarian cancer. Although both subsets recognized exogenous NY-ESO-1 protein pulsed on DP04(+) target cells, only one type recognized target cells with intracellular expression of NY-ESO-1. The tumor-recognizing CD4(+) T cells more efficiently recognized the short 8-9-mer peptides than the non-tumor-recognizing CD4(+) T cells. In addition to endosomal/lysosomal proteases that are typically involved in MHC-II antigen presentation, several pathways in the MHC class I presentation pathways, such as the proteasomal degradation and transporter-associated with antigen-processing-mediated peptide transport, were also involved in the presentation of intracellular NY-ESO-1 on MHC-II. The presentation was inhibited significantly by primaquine, a small molecule that inhibits endosomal recycling, consistent with findings that pharmacologic inhibition of new protein synthesis enhances antigen presentation. Together, our data demonstrate that cancer cells selectively present peptides from intracellular tumor antigens on MHC-II by multiple nonclassical antigen-processing pathways. Harnessing the direct tumor-recognizing ability of CD4(+) T cells could be a promising strategy to enhance antitumor immune responses in the immunosuppressive tumor microenvironment.

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

    PubMed Central

    Nishi, Manami; El-Hage, Sandy; Fox, Barbara A.; Bzik, David J.

    2015-01-01

    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

  15. Necrotizing meningoencephalitis of Pug dogs associates with dog leukocyte antigen class II and resembles acute variant forms of multiple sclerosis.

    PubMed

    Greer, K A; Wong, A K; Liu, H; Famula, T R; Pedersen, N C; Ruhe, A; Wallace, M; Neff, M W

    2010-08-01

    Necrotizing meningoencephalitis (NME) is a disorder of Pug Dogs that appears to have an immune etiology and high heritability based on population studies. The present study was undertaken to identify a genetic basis for the disease. A genome-wide association scan with single tandem repeat (STR) markers showed a single strong association near the dog leukocyte antigen (DLA) complex on CFA12. Fine resolution mapping with 27 STR markers on CFA12 further narrowed association to the region containing DLA-DRB1, -DQA1 and, -DQB1 genes. Sequencing confirmed that affected dogs were more likely to be homozygous for specific alleles at each locus and that these alleles were linked, forming a single high risk haplotype. The strong DLA class II association of NME in Pug Dogs resembles that of human multiple sclerosis (MS). Like MS, NME appears to have an autoimmune basis, involves genetic and nongenetic factors, has a relatively low incidence, is more frequent in females than males, and is associated with a vascularly orientated nonsuppurative inflammation. However, NME of Pug Dogs is more aggressive in disease course than classical human MS, appears to be relatively earlier in onset, and involves necrosis rather than demyelination as the central pathobiologic feature. Thus, Pug Dog encephalitis (PDE) shares clinical features with the less common acute variant forms of MS. Accordingly, NME of Pug Dogs may represent a naturally occurring canine model of certain idiopathic inflammatory disorders of the human central nervous system.

  16. Loss of human leucocyte antigen class I and gain of class II expression are early events in carcinogenesis: clues from a study of Barrett's oesophagus.

    PubMed

    Rajendra, S; Ackroyd, R; Karim, N; Mohan, C; Ho, J J; Kutty, M K

    2006-09-01

    Human leucocyte antigen (HLA) expression is altered in oesophageal carcinomas compared with normal tissue. It is unclear, however, whether this phenotype precedes malignant transformation or results as a consequence of it. To investigate HLA class I and II expression in Barrett's oesophagus and normal squamous oesophageal tissue. Asian patients with Barrett's oesophagus (n = 64) and a control group (n = 60) with a normal oesophagus but without reflux symptoms were recruited using endoscopic and histopathological criteria. Tissue samples were stained with monoclonal antibodies specific for HLA-ABC, HLA-DR alpha chain or HLA-DP/DQ/DR, and scored semiquantitatively. The results of immunohistochemical staining were correlated with clinical and histopathological characteristics of patients. Marked expression of HLA-ABC was observed in 50% of Barrett's oesophagus sections as compared with 68.3% of controls (p = 0.038). HLA-DR staining was seen in 51.6% of Barrett's oesophagus samples versus 11.7% of controls (p<0.001). Expression of HLA-DP/DQ/DR was evident in 73.4% of oesophageal intestinal metaplasia tissue as opposed to 18.3% of controls (p<0.001). Importantly, a total loss of HLA-ABC and a concomitant gain of HLA-DP/DQ/DR expression were seen in 37.5% of patients with Barrett's oesophagus but in none of the controls (p<0.001). Interestingly, this phenotype was associated positively with dysplasia (adjusted p, p* = 0.031) but negatively with non-steroidal anti-inflammatory drug use (p* = 0.004). HLA class I expression is down regulated and class II expression is up regulated in Barrett's oesophagus. As these changes predate malignant transformation, altered major histocompatibility complex expression may be a key event in disease progression, possibly in facilitating evasion from immune surveillance.

  17. Antibodies to major histocompatibility complex class II antigens directly prime neutrophils and cause acute lung injury in a two-event in vivo rat model.

    PubMed

    Kelher, Marguerite R; Banerjee, Anirban; Gamboni, Fabia; Anderson, Cameron; Silliman, Christopher C

    2016-12-01

    Transfusion-related acute lung injury (TRALI) is a significant cause of mortality, especially after transfusions containing antibodies to major histocompatibility complex (MHC) class II antigens. We hypothesize that a first event induces both 1) polymorphonuclear neutrophils (PMNs) to express MHC class II antigens, and 2) activation of the pulmonary endothelium, leading to PMN sequestration, so that the infusion of specific MHC class II antibodies to these antigens causes PMN-mediated acute lung injury (ALI). Rats were treated with saline (NS), endotoxin (lipopolysaccharide [LPS]), or cytokines (interferon-γ [IFNγ], macrophage colony-stimulating factor [MCSF], tumor necrosis factor-α [TNFα]); the PMNs were isolated; and the surface expression of the MHC class II antigen OX6 and priming by OX6 antibodies were measured by flow cytometry or priming assays. A two-event model of ALI was completed with NS, LPS, or IFNγ/MCSF/TNFα (first events) and the infusion of OX6 (second event). Compared with NS incubation, rats treated with either LPS or IFNγ/MCSF/TNFα exhibited OX6 PMN surface expression, OX6 antibodies primed the formyl-methionyl-leucyl phenylalanine (fMLF)-activated respiratory burst, and PMN sequestration was increased. OX6 antibody infusion into LPS-incubated or IFNγ/MCSF/TNFα-incubated rats elicited ALI, the OX6 antibody was present on the PMNs, and PMN depletion abrogated ALI. Proinflammatory first events induce PMN MHC class II surface expression, activation of the pulmonary endothelium, and PMN sequestration such that the infusion of cognate antibodies precipitates TRALI. © 2016 AABB.

  18. Major Histocompatibility Complex Class II Dextramers: New Tools for the Detection of antigen-Specific, CD4 T Cells in Basic and Clinical Research.

    PubMed

    Massilamany, C; Krishnan, B; Reddy, J

    2015-11-01

    The advent of major histocompatibility complex (MHC) tetramer technology has been a major contribution to T cell immunology, because tetramer reagents permit detection of antigen-specific T cells at the single-cell level in heterogeneous populations by flow cytometry. However, unlike MHC class I tetramers, the utility of MHC class II tetramers has been less frequently reported. MHC class II tetramers can be used successfully to enumerate the frequencies of antigen-specific CD4 T cells in cells activated in vitro, but their use for ex vivo analyses continues to be a problem, due in part to their activation dependency for binding with T cells. To circumvent this problem, we recently reported the creation of a new generation of reagents called MHC class II dextramers, which were found to be superior to their counterparts. In this review, we discuss the utility of class II dextramers vis-a-vis tetramers, with respect to their specificity and sensitivity, including potential applications and limitations. © 2015 The Foundation for the Scandinavian Journal of Immunology.

  19. Major histocompatibility complex class II dextramers: New tools for the detection of antigen-specific, CD4 T cells in basic and clinical research

    PubMed Central

    Massilamany, Chandirasegaran; Krishnan, Bharathi; Reddy, Jay

    2015-01-01

    The advent of major histocompatibility complex (MHC) tetramer technology has been a major contribution to T cell immunology, because tetramer reagents permit detection of antigen-specific T cells at the single-cell level in heterogeneous populations by flow cytometry. However, unlike MHC class I tetramers, the utility of MHC class II tetramers has been less frequently reported. MHC class II tetramers can be used successfully to enumerate the frequencies of antigen-specific CD4 T cells in cells activated in vitro, but their use for ex vivo analyses continues to be a problem, due in part to their activation dependency for binding with T cells. To circumvent this problem, we recently reported the creation of a new generation of reagents called MHC class II dextramers, which were found to be superior to their counterparts. In this review, we discuss the utility of class II dextramers vis-a-vis tetramers, with respect to their specificity and sensitivity, including potential applications and limitations. PMID:26207337

  20. Genetic variability in swine leukocyte antigen class II and Toll-like receptors affects immune responses to vaccination for bacterial infections in pigs.

    PubMed

    Shinkai, H; Arakawa, A; Tanaka-Matsuda, M; Ide-Okumura, H; Terada, K; Chikyu, M; Kawarasaki, T; Ando, A; Uenishi, H

    2012-12-01

    The genes encoding swine leukocyte antigen (SLA) and Toll-like receptor (TLR) are highly polymorphic in pig populations, and likely have influences on infection and the effects of vaccination. We explored the associations of different genotypes of SLA class II and of the genes TLR1, TLR4, TLR5, and TLR6 with antibody responses after vaccination against Erysipelothrix rhusiopathiae (ER) and Actinobacillus pleuropneumoniae (APP) serotypes 1, 2, and 5 in 191 Duroc pigs maintained under specific pathogen-free conditions. We demonstrated close relationships between SLA class II and ER antibody response and between TLR genes other than TLR4 and APP antibody responses. Pigs with specific haplotypes in SLA class II or TLR5 showed decreased antibody response to ER vaccination or increased responses to APP2 and APP5 vaccination, respectively. It might be possible to breed for responsiveness to vaccination and to implement new vaccine development strategies unaffected by genetic backgrounds of pigs.

  1. A comparison of the antigen-presenting capabilities of class II MHC-expressing human lung epithelial and endothelial cells.

    PubMed Central

    Cunningham, A C; Zhang, J G; Moy, J V; Ali, S; Kirby, J A

    1997-01-01

    Human lung alveolar epithelial cells constitutively express class II major histocompatibility complex (MHC). Human lung microvascular endothelial and small airway epithelial cells can be induced to express class II MHC by stimulation with the pro-inflammatory cytokine interferon-gamma. The levels of class II MHC on lung epithelial and endothelial cells were comparable to those seen on an Epstein-Barr virus (EBV)-transformed B-cell line. However, the costimulatory molecules B7-1 and B7-2 were not expressed. The ability of the class II MHC expressing human lung parenchymal cells to present alloantigen to CD4+ T lymphocytes was investigated. Freshly isolated human alveolar epithelial cells (type II pneumocytes) and monolayers of interferon-gamma-stimulated small airway epithelial and lung microvascular endothelial cells were co-cultured with allogeneic CD4+ T lymphocytes and proliferation determined by [3H]thymidine incorporation. A clear difference was observed between effects of the epithelial and endothelial cells on CD4+ T-lymphocyte activation. Alveolar and small airway epithelial cells failed to stimulate the proliferation of allogeneic CD4+ T lymphocytes whereas lung microvascular endothelial cells did stimulate proliferation. This difference could not be explained by the levels of class II MHC or the lack of B7-1 and B7-2 solely. Microvascular endothelial cells, and not alveolar or small airway epithelial cells, possess B7-independent costimulatory pathways. PMID:9301537

  2. Antiviral CD8(+) T Cells Restricted by Human Leukocyte Antigen Class II Exist during Natural HIV Infection and Exhibit Clonal Expansion.

    PubMed

    Ranasinghe, Srinika; Lamothe, Pedro A; Soghoian, Damien Z; Kazer, Samuel W; Cole, Michael B; Shalek, Alex K; Yosef, Nir; Jones, R Brad; Donaghey, Faith; Nwonu, Chioma; Jani, Priya; Clayton, Gina M; Crawford, Frances; White, Janice; Montoya, Alana; Power, Karen; Allen, Todd M; Streeck, Hendrik; Kaufmann, Daniel E; Picker, Louis J; Kappler, John W; Walker, Bruce D

    2016-10-18

    CD8(+) T cell recognition of virus-infected cells is characteristically restricted by major histocompatibility complex (MHC) class I, although rare examples of MHC class II restriction have been reported in Cd4-deficient mice and a macaque SIV vaccine trial using a recombinant cytomegalovirus vector. Here, we demonstrate the presence of human leukocyte antigen (HLA) class II-restricted CD8(+) T cell responses with antiviral properties in a small subset of HIV-infected individuals. In these individuals, T cell receptor β (TCRβ) analysis revealed that class II-restricted CD8(+) T cells underwent clonal expansion and mediated killing of HIV-infected cells. In one case, these cells comprised 12% of circulating CD8(+) T cells, and TCRα analysis revealed two distinct co-expressed TCRα chains, with only one contributing to binding of the class II HLA-peptide complex. These data indicate that class II-restricted CD8(+) T cell responses can exist in a chronic human viral infection, and may contribute to immune control. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Membrane Ia expression and antigen-presenting accessory cell function of L cells transfected with class II major histocompatibility complex genes

    PubMed Central

    1984-01-01

    To study the relationship between the structure and function of Ia antigens, as well as the physiologic requirements for antigen presentation to major histocompatibility complex-restricted T cells, class II A alpha and A beta genes from the k and d haplotypes were transfected into Ltk- fibroblasts using the calcium phosphate coprecipitation technique. Individually transfected genes were actively transcribed in the L cells without covalent linkage to, or cotransformation with, viral enhancer sequences. However, cell surface expression of detectable I-A required the presence of transfected A alpha dA beta d or A alpha kA beta k pairs in a single cell. The level of I-A expression under these conditions was 1/5-1/10 that of Ia+ B lymphoma cells, or B lymphoma cells expressing transfected class II genes. These I-A-expressing transfectants were tested for accessory cell function and shown to present polypeptide and complex protein antigens to T cell clones and hybridomas in the context of the transfected gene products. One T cell clone, restricted to I-Ak plus GAT (L-glutamic acid60-L-alanine30-L-tyrosine10), had a profound cytotoxic effect on I-Ak- but not I-Ad-expressing transfectants in the presence of specific antigen. Assays of unprimed T cells showed that both Ia+ and Ia- L cells could serve as accessory cells for concanavalin A-induced proliferative responses. These data indicate that L cells can transcribe, translate, and express transfected class II genes and that such I-A-bearing L cells possess the necessary metabolic mechanisms for presenting these antigens to T lymphocytes in the context of their I-A molecules. PMID:6436430

  4. Cost effective and time efficient measurement of CD4, CD8, major histocompatibility complex Class II, and macrophage antigen expression in the lungs of chickens.

    PubMed

    Fletcher, Oscar J; Tan, Xun; Cortes, Lucia; Gimeno, Isabel

    2012-05-15

    Cells expressing CD4, CD8, major histocompatibility complex (MHC) Class II, and macrophage biomarkers in lungs of chickens were quantified by measuring total area of antigen expressed using imageJ, a software program developed at the National Institutes of Health and available at no cost. The procedures reported here were rapid, and reproducible. Total area of antigen expressed had positive correlation with manual counts of cells expressing CD4 and CD8 biomarkers after inoculation with serotype 1 Marek's disease virus (MDV) vaccines. Visual inspection and overlays prepared from outlines of cells counted by imageJ confirmed agreement between antigen expression and area measured. Total area measured was not dependent on time of image acquisition from randomly selected fields from the same slides. Total area values were not computer specific, but acquisition of the original images required standardization of microscope used and camera setup. All steps in the process from sample collection through sectioning, staining, and image acquisition must be standardized as much as possible. Chickens infected with a very virulent+ (vv(+)) isolate of MDV (648A) had increased CD4, CD8, MHC Class II, and macrophage biomarker expression compared to noninfected control chickens at 10 days post infection, but variable responses depending on the specific biomarker measured at 3 and 5 days post infection. The procedure described here is faster and more reproducible than manual counting in cases (CD4 and CD8) where the number of positive cells is low enough for manual counts. Manual counting is not possible with MHC Class II and macrophage antigens nor when CD4(+) cells are present in large numbers following proliferation to tumors, thus subjective systems are used for scoring in these conditions. Using imageJ as described eliminates the need for subjective and less reproducible methods for measuring expression of these antigens.

  5. Host DNA released in response to aluminum adjuvant enhances MHC class II-mediated antigen presentation and prolongs CD4 T-cell interactions with dendritic cells

    PubMed Central

    McKee, Amy S.; Burchill, Matthew A.; Munks, Michael W.; Jin, Lei; Kappler, John W.; Friedman, Rachel S.; Jacobelli, Jordan; Marrack, Philippa

    2013-01-01

    Many vaccines include aluminum salts (alum) as adjuvants despite little knowledge of alum’s functions. Host DNA rapidly coats injected alum. Here, we further investigated the mechanism of alum and DNA’s adjuvant function. Our data show that DNase coinjection reduces CD4 T-cell priming by i.m. injected antigen + alum. This effect is partially replicated in mice lacking stimulator of IFN genes, a mediator of cellular responses to cytoplasmic DNA. Others have shown that DNase treatment impairs dendritic cell (DC) migration from the peritoneal cavity to the draining lymph node in mice immunized i.p. with alum. However, our data show that DNase does not affect accumulation of, or expression of costimulatory proteins on, antigen-loaded DCs in lymph nodes draining injected muscles, the site by which most human vaccines are administered. DNase does inhibit prolonged T-cell–DC conjugate formation and antigen presentation between antigen-positive DCs and antigen-specific CD4 T cells following i.m. injection. Thus, from the muscle, an immunization site that does not require host DNA to promote migration of inflammatory DCs, alum acts as an adjuvant by introducing host DNA into the cytoplasm of antigen-bearing DCs, where it engages receptors that promote MHC class II presentation and better DC–T-cell interactions. PMID:23447566

  6. Pandemic 2009 H1N1 Influenza Venus reporter virus reveals broad diversity of MHC class II-positive antigen-bearing cells following infection in vivo.

    PubMed

    DiPiazza, Anthony; Nogales, Aitor; Poulton, Nicholas; Wilson, Patrick C; Martínez-Sobrido, Luis; Sant, Andrea J

    2017-09-07

    Although it is well established that Influenza A virus infection is initiated in the respiratory tract, the sequence of events and the cell types that become infected or access viral antigens remains incompletely understood. In this report, we used a novel Influenza A/California/04/09 (H1N1) reporter virus that stably expresses the Venus fluorescent protein to identify antigen-bearing cells over time in a mouse model of infection using flow cytometry. These studies revealed that many hematopoietic cells, including subsets of monocytes, macrophages, dendritic cells, neutrophils and eosinophils acquire influenza antigen in the lungs early post-infection. Surface staining of the viral HA revealed that most cell populations become infected, most prominently CD45(neg) cells, alveolar macrophages and neutrophils. Finally, differences in infection status, cell lineage and MHC class II expression by antigen-bearing cells correlated with differences in their ability to re-stimulate influenza-specific CD4 T cells ex vivo. Collectively, these studies have revealed the cellular heterogeneity and complexity of antigen-bearing cells within the lung and their potential as targets of antigen recognition by CD4 T cells.

  7. Early and aggressive treatment of rheumatoid arthritis patients affects the association of HLA class II antigens with progression of joint damage.

    PubMed

    Lard, L R; Boers, M; Verhoeven, A; Vos, K; Visser, H; Hazes, J M W; Zwinderman, A H; Schreuder, G M T; Breedveld, F C; De Vries, R R P; van der Linden, S; Zanelli, E; Huizinga, T W J

    2002-04-01

    The presence of certain HLA class II antigens is strongly associated with the progression of joint destruction in rheumatoid arthritis (RA). Such antigens may be more effective than other class II antigens in inducing the formation of autoreactive T cells after presentation of (auto)antigens. We investigated whether early and aggressive treatment with disease-modifying antirheumatic drugs could modify this relationship. We analyzed data from 2 studies of patients with early RA treated according to different strategies. The first study consisted of 2 cohorts, one (n = 109; median disease duration before treatment 4 months) was treated according to the pyramid strategy (initial nonsteroidal antiinflammatory drugs, followed by chloroquine [CQ] or sulfasalazine [SSZ] when necessary), and the other (n = 97; median disease duration before treatment 2 weeks) was immediately treated with CQ or SSZ. The second study comprised 155 patients (median disease duration 4 months) from the Combinatietherapie Bij Reumatoide Artritis (COBRA) trial, in which patients were randomly assigned to combination treatment with step-down prednisolone, methotrexate (MTX), and SSZ (n = 76) or with SSZ alone (n = 79). Prednisolone and MTX dosages were tapered and stopped after 28 and 40 weeks, respectively. The extent of joint damage was measured by the modified Sharp method. In the pyramid treatment cohort, the median increase in Sharp score after 2 years was 12 in patients positive for the shared epitope (SE) and 1 in SE- patients. In the immediate treatment cohort, the median increase was 3 in SE+ patients and 2 in SE- patients. In the SSZ group of the COBRA study, the median increase in Sharp score after 1 year was 11 in DR4+ patients and 3 in DR4- patients. In the combination treatment group, the median increase was 4 in DR4+ patients and 2 in DR4- patients. Significance was confirmed by multiple regression using log-transformed scores. Early and aggressive antirheumatic drug treatment

  8. The impact of HLA class I and EBV latency-II antigen-specific CD8(+) T cells on the pathogenesis of EBV(+) Hodgkin lymphoma.

    PubMed

    Jones, K; Wockner, L; Brennan, R M; Keane, C; Chattopadhyay, P K; Roederer, M; Price, D A; Cole, D K; Hassan, B; Beck, K; Gottlieb, D; Ritchie, D S; Seymour, J F; Vari, F; Crooks, P; Burrows, S R; Gandhi, M K

    2016-02-01

    In 40% of cases of classical Hodgkin lymphoma (cHL), Epstein-Barr virus (EBV) latency-II antigens [EBV nuclear antigen 1 (EBNA1)/latent membrane protein (LMP)1/LMP2A] are present (EBV(+) cHL) in the malignant cells and antigen presentation is intact. Previous studies have shown consistently that HLA-A*02 is protective in EBV(+) cHL, yet its role in disease pathogenesis is unknown. To explore the basis for this observation, gene expression was assessed in 33 cHL nodes. Interestingly, CD8 and LMP2A expression were correlated strongly and, for a given LMP2A level, CD8 was elevated markedly in HLA-A*02(-) versus HLA-A*02(+) EBV(+) cHL patients, suggesting that LMP2A-specific CD8(+) T cell anti-tumoral immunity may be relatively ineffective in HLA-A*02(-) EBV(+) cHL. To ascertain the impact of HLA class I on EBV latency antigen-specific immunodominance, we used a stepwise functional T cell approach. In newly diagnosed EBV(+) cHL, the magnitude of ex-vivo LMP1/2A-specific CD8(+) T cell responses was elevated in HLA-A*02(+) patients. Furthermore, in a controlled in-vitro assay, LMP2A-specific CD8(+) T cells from healthy HLA-A*02 heterozygotes expanded to a greater extent with HLA-A*02-restricted compared to non-HLA-A*02-restricted cell lines. In an extensive analysis of HLA class I-restricted immunity, immunodominant EBNA3A/3B/3C-specific CD8(+) T cell responses were stimulated by numerous HLA class I molecules, whereas the subdominant LMP1/2A-specific responses were confined largely to HLA-A*02. Our results demonstrate that HLA-A*02 mediates a modest, but none the less stronger, EBV-specific CD8(+) T cell response than non-HLA-A*02 alleles, an effect confined to EBV latency-II antigens. Thus, the protective effect of HLA-A*02 against EBV(+) cHL is not a surrogate association, but reflects the impact of HLA class I on EBV latency-II antigen-specific CD8(+) T cell hierarchies. © 2015 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on

  9. Prolonged interferon-gamma application by subcutaneous infusion in cancer patients: differential response of serum CD14, neopterin, and monocyte HLA class I and II antigens.

    PubMed

    Landmann, R; Ludwig, C; Wesp, M; Fisscher, A; Obrist, R; Knüsli, C; Denz, H; Obrecht, J P

    1992-04-01

    This study reports on biological response modification induced by prolonged continuous subcutaneous (s.c.) infusion of recombinant interferon-gamma (rIFN-gamma) with particular attention to changes of soluble CD14. This glycoprotein with an unknown function is derived from myeloid cells carrying membrane CD14, which is the receptor for lipopolysaccharide (LPS)-LPS-binding protein (LBP) complexes. Fifteen metastatic cancer patients received weekly escalating doses of rIFN-gamma starting at either 50 or 100 micrograms/24 h and increasing up to 400 micrograms/24 h for a median duration of 6 weeks. The maximum tolerated dose was higher (200 micrograms/24 h) with the lower (50 micrograms/24 h) starting dose. Biological activity of rIFN-gamma was evaluated by weekly measurements of CD14, neopterin, and beta 2-microglobulin concentrations in serum as well as monocyte HLA class I and II antigen expression and tumor cytotoxicity. Serum IFN-gamma concentrations increased 20-fold within 4 weeks of therapy. The levels were correlated to the mean dose (r = 0.95, p less than 0.05). Among the biological markers, two patterns were observed. First, serum CD14 concentration and expression of monocyte HLA class II antigens increased significantly during the first week, and marker expression correlated with serum IFN-gamma levels (p less than 0.05); CD14 and HLA class II antigens thereafter returned to pretreatment levels within 4 weeks of therapy despite persistently elevated serum IFN-gamma concentrations. Second, serum neopterin and beta 2-microglobulin concentrations as well as monocyte HLA class I expression also increased significantly within the first week, but remained elevated thereafter without any further dose relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Identification of a novel major histocompatibility complex class II-restricted tumor antigen resulting from a chromosomal rearrangement recognized by CD4(+) T cells.

    PubMed

    Wang, R F; Wang, X; Rosenberg, S A

    1999-05-17

    CD4(+) T cells play an important role in antitumor immune responses and autoimmune and infectious diseases. Although many major histocompatibility complex (MHC) class I-restricted tumor antigens have been identified in the last few years, little is known about MHC class II- restricted human tumor antigens recognized by CD4(+) T cells. Here, we describe the identification of a novel melanoma antigen recognized by an human histocompatibility leukocyte antigen (HLA)-DR1-restricted CD4(+) tumor-infiltrating lymphocyte (TIL)1363 using a genetic cloning approach. DNA sequencing analysis indicated that this was a fusion gene generated by a low density lipid receptor (LDLR) gene in the 5' end fused to a GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferase (FUT) in an antisense orientation in the 3' end. The fusion gene encoded the first five ligand binding repeats of LDLR in the NH2 terminus followed by a new polypeptide translated in frame with LDLR from the FUT gene in an antisense direction. Southern blot analysis showed that chromosomal DNA rearrangements occurred in the 1363mel cell line. Northern blot analysis detected two fusion RNA transcripts present only in the autologous 1363mel, but not in other cell lines or normal tissues tested. Two minimal peptides were identified from the COOH terminus of the fusion protein. This represents the first demonstration that a fusion protein resulting from a chromosomal rearrangement in tumor cells serves as an immune target recognized by CD4(+) T cells.

  11. Combined Linkage and Association Studies Show that HLA Class II Variants Control Levels of Antibodies against Epstein-Barr Virus Antigens

    PubMed Central

    Cobat, Aurélie; Guergnon, Julien; Brice, Pauline; Fermé, Christophe; Carde, Patrice; Hermine, Olivier; Pendeven, Catherine Le-; Amiel, Corinne; Taoufik, Yassine; Alcaïs, Alexandre; Theodorou, Ioannis; Besson, Caroline; Abel, Laurent

    2014-01-01

    Over 95% of the adult population worldwide is infected with Epstein-Barr virus (EBV). EBV infection is associated with the development of several cancers, including Hodgkin lymphoma (HL). Elevated levels of anti-EBV antibodies have been associated with increased risk of HL. There is growing evidence that genetic factors control the levels of antibodies against EBV antigens. Here, we conducted linkage and association studies to search for genetic factors influencing either anti-viral capsid antigen (VCA) or anti-Epstein Barr nuclear antigen-1 (EBNA-1) IgG levels in a unique cohort of 424 individuals of European origin from 119 French families recruited through a Hodgkin lymphoma (HL) patient. No major locus controlling anti-VCA antibody levels was identified. However, we found that the HLA region influenced anti-EBNA-1 IgG titers. Refined association studies in this region identified a cluster of HLA class II variants associated with anti-EBNA-1 IgG titers (e.g. p = 5×10–5 for rs9268403). The major allele of rs9268403 conferring a predisposition to high anti-EBNA-1 antibody levels was also associated with an increased risk of HL (p = 0.02). In summary, this study shows that HLA class II variants influenced anti-EBNA-1 IgG titers in a European population. It further shows the role of the same variants in the risk of HL. PMID:25025336

  12. Combined linkage and association studies show that HLA class II variants control levels of antibodies against Epstein-Barr virus antigens.

    PubMed

    Pedergnana, Vincent; Syx, Laurène; Cobat, Aurélie; Guergnon, Julien; Brice, Pauline; Fermé, Christophe; Carde, Patrice; Hermine, Olivier; Le-Pendeven, Catherine; Amiel, Corinne; Taoufik, Yassine; Alcaïs, Alexandre; Theodorou, Ioannis; Besson, Caroline; Abel, Laurent

    2014-01-01

    Over 95% of the adult population worldwide is infected with Epstein-Barr virus (EBV). EBV infection is associated with the development of several cancers, including Hodgkin lymphoma (HL). Elevated levels of anti-EBV antibodies have been associated with increased risk of HL. There is growing evidence that genetic factors control the levels of antibodies against EBV antigens. Here, we conducted linkage and association studies to search for genetic factors influencing either anti-viral capsid antigen (VCA) or anti-Epstein Barr nuclear antigen-1 (EBNA-1) IgG levels in a unique cohort of 424 individuals of European origin from 119 French families recruited through a Hodgkin lymphoma (HL) patient. No major locus controlling anti-VCA antibody levels was identified. However, we found that the HLA region influenced anti-EBNA-1 IgG titers. Refined association studies in this region identified a cluster of HLA class II variants associated with anti-EBNA-1 IgG titers (e.g. p = 5×10(-5) for rs9268403). The major allele of rs9268403 conferring a predisposition to high anti-EBNA-1 antibody levels was also associated with an increased risk of HL (p = 0.02). In summary, this study shows that HLA class II variants influenced anti-EBNA-1 IgG titers in a European population. It further shows the role of the same variants in the risk of HL.

  13. Mycobacterium tuberculosis Synergizes with ATP To Induce Release of Microvesicles and Exosomes Containing Major Histocompatibility Complex Class II Molecules Capable of Antigen Presentation ▿ †

    PubMed Central

    Ramachandra, Lakshmi; Qu, Yan; Wang, Ying; Lewis, Colleen J.; Cobb, Brian A.; Takatsu, Kiyoshi; Boom, W. Henry; Dubyak, George R.; Harding, Clifford V.

    2010-01-01

    Major histocompatibility complex class II (MHC-II) molecules are released by murine macrophages upon lipopolysaccharide (LPS) stimulation and ATP signaling through the P2X7 receptor. These studies show that infection of macrophages with Mycobacterium tuberculosis or M. bovis strain BCG enhances MHC-II release in synergy with ATP. Shed MHC-II was contained in two distinct organelles, exosomes and plasma membrane-derived microvesicles, which were both able to present exogenous antigenic peptide to T hybridoma cells. Furthermore, microvesicles from mycobacterium-infected macrophages were able to directly present M. tuberculosis antigen (Ag) 85B(241-256)-I-Ab complexes that were generated by the processing of M. tuberculosis Ag 85B in infected cells to both M. tuberculosis-specific T hybridoma cells and naïve P25 M. tuberculosis T-cell receptor (TCR)-transgenic T cells. In the presence of prefixed macrophages, exosomes from mycobacterium-infected macrophages provided weak stimulation to M. tuberculosis-specific T hybridoma cells but not naïve P25 T cells. Thus, infection with M. tuberculosis primes macrophages for the increased release of exosomes and microvesicles bearing M. tuberculosis peptide-MHC-II complexes that may generate antimicrobial T-cell responses. PMID:20837713

  14. Swine leukocyte antigen class II genes (SLA-DRA, SLA-DRB1, SLA-DQA, SLA-DQB1) polymorphism and genotyping in Guizhou minipigs.

    PubMed

    Liu, Z Z; Xia, J H; Xin, L L; Wang, Z G; Qian, L; Wu, S G; Yang, S L; Li, K

    2015-11-30

    The swine leukocyte antigen (SLA) complex harbors highly polymorphic gene clusters encoding glycoproteins that are involved in responses to vaccines, infectious disease, and production performance. Pigs with well-defined SLA class II genes are useful for the study of disease, immunology, and vaccines. In this study, we analyzed four SLA class II genes (SLA-DRA, SLA-DRB1, SLA-DQA, SLA-DQB1) in 22 founder Guizhou minipigs using a sequence-based typing method. Twelve alleles were detected, compared with the SLA class II allele sequences in the GenBank, and one of twelve alleles was found to be novel in Guizhou minipigs. There are four SLA II haplotypes, and one of them has been previously reported in Meishan pigs. Furthermore, based on sequence information of these alleles, we developed a simple SLA typing method implemented to SLA-typing for unknown offspring of Guizhou minipigs, relying on designed twelve sequence specific primers that could discriminate between each other. According to the combination of sequence-based typing and PCR-SSP, we were able to rapidly check SLA typing of Guizhou breeding stock and identified four SLA haplotypes in the herd. Therefore, SLA-defined Guizhou minipigs will be useful as animal models for xenotransplantation and immunological research.

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

    PubMed

    Cantú de León, David; Pérez-Montiel, Delia; Villavicencio, Verónica; García Carranca, Alejandro; Mohar Betancourt, Alejandro; Acuña-Alonzo, Victor; López-Tello, Alberto; Vargas-Alarcón, Gilberto; Barquera, Rodrigo; Yu, Neng; Yunis, Edmond J; Granados, Julio

    2009-02-05

    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

  16. Pediatric adrenocortical tumors: morphological diagnostic criteria and immunohistochemical expression of matrix metalloproteinase type 2 and human leucocyte-associated antigen (HLA) class II antigens. Results from the Italian Pediatric Rare Tumor (TREP) Study project.

    PubMed

    Magro, Gaetano; Esposito, Giovanni; Cecchetto, Giovanni; Dall'Igna, Patrizia; Marcato, Raffaella; Gambini, Claudio; Boldrini, Renata; Collini, Paola; D'Onofrio, Vittoria; Salfi, Nunzio; d'Amore, Emanuele; Ferrari, Andrea; Bisogno, Gianni; Alaggio, Rita

    2012-01-01

    Pediatric adrenocortical tumors are neoplasms that only rarely occur in pediatric patients. Their clinical behavior is often unpredictable, and the histologic criteria of malignancy used in adults are not always useful in children. The aim of this study was to validate the prognostic value of the pathologic criteria of Wieneke et al and to evaluate the potential prognostic expression of matrix metalloproteinase 2 and human leucocyte-associated antigen (HLA) class II antigens in a series of 20 pediatric patients affected by adrenocortical tumors, who were enrolled in the Italian Pediatric Rare Tumor (TREP) Study between 2000 and 2007. The age range was 0 to 17.5 years (mean, 7.28 years) with a male-female ratio of 1:2. The mean follow-up was 64.4 months. The histologic diagnoses were reviewed, and the cases were classified using the criteria for malignancy proposed by Wieneke et al. The immunohistochemical expression of matrix metalloproteinase 2 and HLA class II antigens was scored by semiquantitative analysis and compared with the clinicopathologic parameters and outcome. Based on the scoring system of Wieneke et al, 7 tumors were classified as malignant; 12 tumors, as benign; and only 1 tumor, with "unpredictable behavior." In all cases, the clinical behavior was consistent with the pathologic criteria of Wieneke et al. Notably, areas of regressive myxoid changes, not included among the criteria of Wieneke et al, were observed in all but 1 case of malignant tumors and only in 2 cases of benign tumors. Matrix metalloproteinase 2 was focally to diffusely expressed in all malignant and in most benign tumors. HLA class II antigens immunoreactivity was absent in all benign tumors and restricted to rare isolated cells in most malignant tumors. Our findings confirm that the pathologic scoring system of Wieneke et al is a simple and reproducible diagnostic tool to predict prognosis in pediatric adrenocortical tumors. Unlike in their adult counterpart, the expression of

  17. Decreased expression of human class II antigens on monocytes from patients with acquired immune deficiency syndrome. Increased expression with interferon-gamma.

    PubMed Central

    Heagy, W; Kelley, V E; Strom, T B; Mayer, K; Shapiro, H M; Mandel, R; Finberg, R

    1984-01-01

    The expression of HLA-DR (a class II histocompatibility antigen) on monocytes isolated from the peripheral blood of normal individuals and patients with acquired immune deficiency syndrome (AIDS) was investigated by the use of dual fluorescent staining and cytofluorometry. In animal models the absence of class II positive monocytes is linked to a failure of T cells to respond to antigens. We now report that patients with AIDS have a paucity of HLA-DR+ monocytes. The percentage of HLA-DR+ monocytes among eight normal individuals ranged from 49.3 to 95.0%+, and only one individual had less than 50% HLA-DR+ monocytes. HLA-DR expression on monocytes from homosexual male patients with lymphadenopathy was similar to that of normal subjects (range, 58.0 to 97.4%+). In contrast, seven of nine patients with AIDS had less than 50% HLA-DR+ monocytes (range, 13.4 to 78.8%+). The in vitro incubation of monocytes from AIDS patients with cloned human interferon-gamma resulted in an increase of the expression of HLA-DR to near normal levels. PMID:6439741

  18. Transcription of a subset of human class II major histocompatibility complex genes is regulated by a nucleoprotein complex that contains c-fos or an antigenically related protein.

    PubMed Central

    Ono, S J; Bazil, V; Levi, B Z; Ozato, K; Strominger, J L

    1991-01-01

    Transcriptional regulation of the human major histocompatibility complex class II genes requires at least two upstream elements, the X and Y boxes, located in the -50- to -150-base-pair region of all class II promoters. The DRA and DPB promoters contain phorbol ester-responsive elements overlapping the 3' side of their X boxes. Mutation of this sequence down-regulates the efficiency of the DRA promoter, suggesting that a positive regulator(s) binds to this site. In this report, anti-sense c-fos RNA and an anti-c-fos antibody were used to show that the product of the protooncogene c-fos or an antigenically related protein is a component of a complex that binds to the X box and is required for maximal transcription from the DRA and DPB promoters. As c-fos (or its related proteins) cannot bind alone to DNA, these results suggest that it may dimerize with other members of the JUN/AP-1 family, such as hXBP1, to participate in the activation of a subset of class II major histocompatibility complex genes. Images PMID:1709740

  19. Increased frequency of class I and II anti-human leukocyte antigen antibodies in systemic lupus erythematosus and scleroderma and associated factors: a comparative study.

    PubMed

    Tozkir, Hilmi; Pamuk, Omer Nuri; Duymaz, Julide; Gurkan, Hakan; Yazar, Metin; Sari, Gulce; Tanrikulu, Hazel; Pamuk, Gulsum Emel

    2016-12-01

    There is significant autoantibody production in systemic lupus erythematosus (SLE) and scleroderma (SSc); microchimerism is also thought to play a role in pathogenesis. We determined the frequency of anti-HLA antibodies in SLE and SSc patients and evaluated associated clinical factors. We included 77 SLE patients, 46 SSc patients and 53 healthy controls into the study. Clinical data about the patients were obtained from hospital records. Anti-human leukocyte (anti-HLA) antigen antibody analysis of sera was performed by applying Lifecodes anti-HLA Class I and Class II Screening kits based on xMAP technology. The frequencies of class I and II anti-HLA antibodies were significantly higher in SLE (27.3% and 41.6%) and SSc (26.1% and 41.3%) groups than in healthy controls (1.9% and 5.7%) (all P < 0.001). Frequencies of thrombocytopenia (P = 0.021), anti-ribonucleoprotein (P = 0.037) and anti-Ro (P = 0.027) were significantly higher in the class I antibody-positive SLE group; however, pericarditis was less frequent (P = 0.05). On the other hand, the class II antibody-positive SLE group had more frequent anti-ribosomal P antibody (P = 0.038), but less frequent active disease (P = 0.038). In the SSc group, class I antibody-positive patients had more frequent digital ulcers (P = 0.048) and anti-centromere antibodies (P = 0.01). There was no association of anti-HLA antibodies with pulmonary hypertension and interstitial fibrosis in SSc patients. Both class I and class II antibodies were found to be significantly increased in SLE and SSc. Rather than major organ involvement, anti-HLA antibodies were associated with the presence of other antibodies in both diseases. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  20. Bovine leukocyte antigen major histocompatibility complex class II DRB3*2703 and DRB3*1501 alleles are associated with variation in levels of protection against Theileria parva challenge following immunization with the sporozoite p67 antigen.

    PubMed

    Ballingall, Keith T; Luyai, Anthony; Rowlands, G John; Sales, Jill; Musoke, Anthony J; Morzaria, Subash P; McKeever, Declan J

    2004-05-01

    Initial laboratory trials of an experimental subunit vaccine against Theileria parva based on the 67-kDa major sporozoite surface antigen revealed a range of responses to challenge. We have analyzed convergence in seven sets of monozygotic twins which suggests that genetic factors may have an influence in determining the degree of protection provided by p67 immunization. In addition, we have examined whether allelic diversity at major histocompatibility complex class II loci influences protection. Analysis of bovine leukocyte antigen DRB3 diversity in 201 animals identified significant associations with vaccine success (DRB3*2703; P = 0.027) and vaccine failure (DRB3*1501; P = 0.013). Furthermore, DRB3*2703 was associated with the likelihood of immunized animals showing little to no clinical signs of disease following challenge. We discuss the acquired and innate immune mechanisms that may be behind the associations described here.

  1. Brucella abortus Inhibits Major Histocompatibility Complex Class II Expression and Antigen Processing through Interleukin-6 Secretion via Toll-Like Receptor 2▿

    PubMed Central

    Barrionuevo, Paula; Cassataro, Juliana; Delpino, M. Victoria; Zwerdling, Astrid; Pasquevich, Karina A.; Samartino, Clara García; Wallach, Jorge C.; Fossati, Carlos A.; Giambartolomei, Guillermo H.

    2008-01-01

    The strategies that allow Brucella abortus to survive inside macrophages for prolonged periods and to avoid the immunological surveillance of major histocompatibility complex class II (MHC-II)-restricted gamma interferon (IFN-γ)-producing CD4+ T lymphocytes are poorly understood. We report here that infection of THP-1 cells with B. abortus inhibited expression of MHC-II molecules and antigen (Ag) processing. Heat-killed B. abortus (HKBA) also induced both these phenomena, indicating the independence of bacterial viability and involvement of a structural component of the bacterium. Accordingly, outer membrane protein 19 (Omp19), a prototypical B. abortus lipoprotein, inhibited both MHC-II expression and Ag processing to the same extent as HKBA. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited MHC-II expression, indicating that any Brucella lipoprotein could down-modulate MHC-II expression and Ag processing. Inhibition of MHC-II expression and Ag processing by either HKBA or lipidated Omp19 (L-Omp19) depended on Toll-like receptor 2 and was mediated by interleukin-6. HKBA or L-Omp19 also inhibited MHC-II expression and Ag processing of human monocytes. In addition, exposure to the synthetic lipohexapeptide inhibited Ag-specific T-cell proliferation and IFN-γ production of peripheral blood mononuclear cells from Brucella-infected patients. Together, these results indicate that there is a mechanism by which B. abortus may prevent recognition by T cells to evade host immunity and establish a chronic infection. PMID:17984211

  2. Brucella abortus inhibits major histocompatibility complex class II expression and antigen processing through interleukin-6 secretion via Toll-like receptor 2.

    PubMed

    Barrionuevo, Paula; Cassataro, Juliana; Delpino, M Victoria; Zwerdling, Astrid; Pasquevich, Karina A; García Samartino, Clara; Wallach, Jorge C; Fossati, Carlos A; Giambartolomei, Guillermo H

    2008-01-01

    The strategies that allow Brucella abortus to survive inside macrophages for prolonged periods and to avoid the immunological surveillance of major histocompatibility complex class II (MHC-II)-restricted gamma interferon (IFN-gamma)-producing CD4+ T lymphocytes are poorly understood. We report here that infection of THP-1 cells with B. abortus inhibited expression of MHC-II molecules and antigen (Ag) processing. Heat-killed B. abortus (HKBA) also induced both these phenomena, indicating the independence of bacterial viability and involvement of a structural component of the bacterium. Accordingly, outer membrane protein 19 (Omp19), a prototypical B. abortus lipoprotein, inhibited both MHC-II expression and Ag processing to the same extent as HKBA. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited MHC-II expression, indicating that any Brucella lipoprotein could down-modulate MHC-II expression and Ag processing. Inhibition of MHC-II expression and Ag processing by either HKBA or lipidated Omp19 (L-Omp19) depended on Toll-like receptor 2 and was mediated by interleukin-6. HKBA or L-Omp19 also inhibited MHC-II expression and Ag processing of human monocytes. In addition, exposure to the synthetic lipohexapeptide inhibited Ag-specific T-cell proliferation and IFN-gamma production of peripheral blood mononuclear cells from Brucella-infected patients. Together, these results indicate that there is a mechanism by which B. abortus may prevent recognition by T cells to evade host immunity and establish a chronic infection.

  3. Association of the bovine leukocyte antigen major histocompatibility complex class II DRB3*4401 allele with host resistance to the Lone Star tick, Amblyomma americanum.

    PubMed

    Untalan, Pia M; Pruett, John H; Steelman, C Dayton

    2007-04-10

    The MHC of cattle, known as the bovine leukocyte antigen (BoLA) complex, plays an integral role in disease and parasite susceptibility, and immune responsiveness of the host. While susceptibility to tick infestation in cattle is believed to be heritable, genes that may be responsible for the manifestation of this phenotype remain elusive. In an effort to analyze the role that genes within the BoLA complex may play in host resistance to ticks, we have evaluated components of this system within a herd of cattle established at our laboratory that has been phenotyped for ectoparasite susceptibility. Of three microsatellite loci within the BoLA complex analyzed, alleles of two microsatellite loci within the BoLA class IIa cluster (DRB1-118 and DRB3-174) associated with the tick-resistant phenotype, prompting further investigation of gene sequences within the DRB3 region. DRB3 is a class IIa gene, the second exon of which is highly polymorphic since it encodes the antigen recognition site of the DR class II molecule. Analysis of the second exon of the DRB3 gene from the phenotyped calves in our herd revealed a significant association between the DRB3*4401 allele and the tick-resistant phenotype. To our knowledge, this is the first report of a putative association between a class IIa DRB3 sequence and host resistance to the Lone Star tick. Elucidation of the mechanism involved in tick resistance will contribute to improving breeding schemes for parasite resistance, which will be beneficial to the cattle industry.

  4. Dog leukocyte antigen class II-associated genetic risk testing for immune disorders of dogs: simplified approaches using Pug dog necrotizing meningoencephalitis as a model.

    PubMed

    Pedersen, Niels; Liu, Hongwei; Millon, Lee; Greer, Kimberly

    2011-01-01

    A significantly increased risk for a number of autoimmune and infectious diseases in purebred and mixed-breed dogs has been associated with certain alleles or allele combinations of the dog leukocyte antigen (DLA) class II complex containing the DRB1, DQA1, and DQB1 genes. The exact level of risk depends on the specific disease, the alleles in question, and whether alleles exist in a homozygous or heterozygous state. The gold standard for identifying high-risk alleles and their zygosity has involved direct sequencing of the exon 2 regions of each of the 3 genes. However, sequencing and identification of specific alleles at each of the 3 loci are relatively expensive and sequencing techniques are not ideal for additional parentage or identity determination. However, it is often possible to get the same information from sequencing only 1 gene given the small number of possible alleles at each locus in purebred dogs, extensive homozygosity, and tendency for disease-causing alleles at each of the 3 loci to be strongly linked to each other into haplotypes. Therefore, genetic testing in purebred dogs with immune diseases can be often simplified by sequencing alleles at 1 rather than 3 loci. Further simplification of genetic tests for canine immune diseases can be achieved by the use of alternative genetic markers in the DLA class II region that are also strongly linked with the disease genotype. These markers consist of either simple tandem repeats or single nucleotide polymorphisms that are also in strong linkage with specific DLA class II genotypes and/or haplotypes. The current study uses necrotizing meningoencephalitis of Pug dogs as a paradigm to assess simple alternative genetic tests for disease risk. It was possible to attain identical necrotizing meningoencephalitis risk assessments to 3-locus DLA class II sequencing by sequencing only the DQB1 gene, using 3 DLA class II-linked simple tandem repeat markers, or with a small single nucleotide polymorphism array

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

    PubMed Central

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

    2005-01-01

    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. METHODS: To clarify the impact of HLA class II polymorphisms on viral clearance, we performed a meta-analysis of the published data from 11 studies comparing the frequencies of DQB1*0301 and DRB1*1101 alleles in individuals with spontaneous resolution to those with persistent infection. As we identified the heterogeneity between studies, summary statistical data were calculated based on a random-effect model. RESULTS: Meta-analyses yielded summary estimates-odds ratio (OR) of 2.36 [95%CI (1.62, 3.43), P<0.00001] and 2.02 [95%CI (1.56, 2.62), P<0.00001] for the effects of DQB1*0301 and DRB1*1101 alleles on spontaneous clearance of HCV, respectively. CONCLUSION: These results support the hypothesis that specific HLA class II alleles might influence the susceptibility or resistance to persistent HCV infection. Both DQB1*0301 and DRB1*1101 are protective alleles and present HCV epitopes more effectively to CD4+T lymphocytes than others, and subjects with these two alleles are at a lower risk of developing chronic HCV infection. Large, multi-ethnic confirmatory and well-designed studies are needed to determine the host genetic determinants of HCV infection. PMID:16437632

  6. Prognostic effect of human leukocyte antigen class I and II alleles on chronic hepatitis C patients treated by pegylated interferon-alfa plus ribavirin in Taiwan.

    PubMed

    Tseng, Kuo-Chih; Chang, Chin-Kuo; Chou, An-Liang; Hsieh, Yu-Hsi; Tseng, Chang-An; Lai, Ning-Sheng

    2010-01-01

    To investigate the influence of human leukocyte antigen (HLA) class I and II alleles on the response in chronic hepatitis C (CHC) patients receiving combination therapy with pegylated interferon-alfa and ribavirin. One hundred and six CHC patients who accomplished combination treatment were enrolled. Sixty-seven patients achieved sustained virologic response (SVR). HLA-A, -B, -C, -DR, and -DQ loci were determined by sequence-based genotyping. The effects of virologic variables and HLA alleles on SVR were evaluated by logistic regressions. Univariate analyses showed that SVR was significantly associated with low pre-treatment HCV RNA levels, HCV genotype non-1, high pre-treatment ALT levels, a significant decline of ALT levels from baseline to week 4, and the low body mass index. Among HLA class I and II alleles, the occurrence of SVR was significantly associated with lack of HLA-B60 and existence of HLA-A33 in univariate analyses (OR, 0.33; 95% CI, 0.14-0.77; p = 0.01; OR, 2.16; 95% CI, 0.86-5.45; p = 0.30 with a trend, respectively). Multivariate analyses revealed that HLA-A33 significantly favored SVR after adjusted for potential confounders (OR, 7.86; 95% CI, 1.43-43.30; p value after Holm's procedure = 0.03). HLA-A33 is associated with the achievement of SVR in Taiwanese CHC patients receiving combination therapy with pegylated interferon-alfa plus ribavirin.

  7. LAMP-2C Inhibits MHC Class II Presentation of Cytoplasmic Antigens by Disrupting Chaperone-Mediated Autophagy.

    PubMed

    Pérez, Liliana; McLetchie, Shawna; Gardiner, Gail J; Deffit, Sarah N; Zhou, Delu; Blum, Janice S

    2016-03-15

    Cells use multiple autophagy pathways to sequester macromolecules, senescent organelles, and pathogens. Several conserved isoforms of the lysosome-associated membrane protein-2 (LAMP-2) regulate these pathways influencing immune recognition and responses. LAMP-2A is required for chaperone-mediated autophagy (CMA), which promotes Ag capture and MHC class II (MHCII) presentation in B cells and signaling in T cells. LAMP-2B regulates lysosome maturation to impact macroautophagy and phagocytosis. Yet, far less is known about LAMP-2C function. Whereas LAMP2A and LAMP2B mRNA were broadly detected in human tissues, LAMP2C expression was more limited. Transcripts for the three LAMP2 isoforms increased with B cell activation, although specific gene induction varied depending on TLR versus BCR engagement. To examine LAMP-2C function in human B cells and specifically its role in Ag presentation, we used ectopic gene expression. Increased LAMP-2C expression in B cells did not alter MHCII expression or invariant chain processing, but did perturb cytoplasmic Ag presentation via CMA. MHCII presentation of epitopes from exogenous and membrane Ags was not affected by LAMP-2C expression in B cells. Similarly, changes in B cell LAMP-2C expression did not impact macroautophagy. The gene expression of other LAMP2 isoforms and proteasome and lysosomal proteases activities were unperturbed by LAMP-2C ectopic expression. LAMP-2C levels modulated the steady-state expression of several cytoplasmic proteins that are targeted for degradation by CMA and diminished peptide translocation via this pathway. Thus, LAMP-2C serves as a natural inhibitor of CMA that can selectively skew MHCII presentation of cytoplasmic Ags.

  8. Class II Microcins

    NASA Astrophysics Data System (ADS)

    Vassiliadis, Gaëlle; Destoumieux-Garzón, Delphine; Peduzzi, Jean

    Class II microcins are 4.9- to 8.9-kDa polypeptides produced by and active against enterobacteria. They are classified into two subfamilies according to their structure and their gene cluster arrangement. While class IIa microcins undergo no posttranslational modification, class IIb microcins show a conserved C-terminal sequence that carries a salmochelin-like siderophore motif as a posttranslational modification. Aside from this C-terminal end, which is the signature of class IIb microcins, some sequence similarities can be observed within and between class II subclasses, suggesting the existence of common ancestors. Their mechanisms of action are still under investigation, but several class II microcins use inner membrane proteins as cellular targets, and some of them are membrane-active. Like group B colicins, many, if not all, class II microcins are TonB- and energy-dependent and use catecholate siderophore receptors for recognition/­translocation across the outer membrane. In that context, class IIb microcins are considered to have developed molecular mimicry to increase their affinity for their outer membrane receptors through their salmochelin-like posttranslational modification.

  9. Human leukocyte antigen class II (DRB1 and DQB1) alleles and haplotypes frequencies in patients with pemphigus vulgaris among the Serbian population.

    PubMed

    Zivanovic, D; Bojic, S; Medenica, L; Andric, Z; Popadic, D

    2016-05-01

    The etiology of pemphigus vulgaris (PV) is multifactorial and includes genetic, environmental, hormonal, and immunological factors. Inheritance of certain Human class II leukocyte antigen (HLA) alleles is by far the best-established predisposing factor for the development of PV. Class II HLA alleles vary among racial/ethnic backgrounds. We have determined an association between HLA class II alleles and PV among the Serbian population. A total of 72 patients with confirmed diagnosis of PV were genotyped for HLA class II alleles. HLA frequencies were compared with unrelated healthy bone marrow donors. The statistical significance of differences between patients and controls was evaluated using Fisher's exact test. The DRB1*04 and DRB1*14 allelic groups were associated with PV (P adj = 4.45 × 10(-13) and 4.06 × 10(-19) respectively), while HLA-DRB1*11 was negatively associated with PV (P adj = 0.0067) suggesting a protective role. DRB1*04:02, DRB1*14:04, DQB1*03:02 and DQB1*05:03 alleles were shown to be strongly associated with PV (P adj = 1.63 × 10(-12), 5.20 × 10(-7), 1.28 × 10(-6), and 4.44 × 10(-5), respectively). The frequency of HLA DRB1*04-DQB1*03 and HLA DRB1*14-DQB1*05 haplotypes in PV patients was significantly higher than in controls (31.3% vs 8.8%, P adj =7.66 × 10(-8) and 30.6% vs 6.3%, P adj = 3.22 × 10(-10), respectively). At high-resolution level, statistical significance was observed in HLA-DRB1*04:02-DQB1*03:02 and HLA-DRB1*14:04-DQB1*05:03 haplotypes (P adj = 5.55 × 10(-12), and P adj = 3.91 × 10(-6), respectively). Our findings suggest that HLA-DRB1*04:02, DRB1*14:04, HLA-DQB1* 03:02 and DQB1*05:03 alleles and HLA-DRB1*04:02-DQB1*03:02 and HLA-DRB1*14:04-DQB1*05:03 haplotypes are genetic markers for susceptibility for PV, while DRB1*11 allelic group appears protective in Serbian population.

  10. Disruption of Hydrogen Bonds between Major Histocompatibility Complex Class II and the Peptide N-Terminus Is Not Sufficient to Form a Human Leukocyte Antigen-DM Receptive State of Major Histocompatibility Complex Class II

    PubMed Central

    Schulze, Monika-Sarah E. D.; Anders, Anne-Kathrin; Sethi, Dhruv K.; Call, Melissa J.

    2013-01-01

    Peptide presentation by MHC class II is of critical importance to the function of CD4+ T cells. HLA-DM resides in the endosomal pathway and edits the peptide repertoire of newly synthesized MHC class II molecules before they are exported to the cell surface. HLA-DM ensures MHC class II molecules bind high affinity peptides by targeting unstable MHC class II:peptide complexes for peptide exchange. Research over the past decade has implicated the peptide N-terminus in modulating the ability of HLA-DM to target a given MHC class II:peptide combination. In particular, attention has been focused on both the hydrogen bonds between MHC class II and peptide, and the occupancy of the P1 anchor pocket. We sought to solve the crystal structure of a HLA-DR1 molecule containing a truncated hemagglutinin peptide missing three N-terminal residues compared to the full-length sequence (residues 306–318) to determine the nature of the MHC class II:peptide species that binds HLA-DM. Here we present structural evidence that HLA-DR1 that is loaded with a peptide truncated to the P1 anchor residue such that it cannot make select hydrogen bonds with the peptide N-terminus, adopts the same conformation as molecules loaded with full-length peptide. HLA-DR1:peptide combinations that were unable to engage up to four key hydrogen bonds were also unable to bind HLA-DM, while those truncated to the P2 residue bound well. These results indicate that the conformational changes in MHC class II molecules that are recognized by HLA-DM occur after disengagement of the P1 anchor residue. PMID:23976922

  11. Type I interferon drives a distinctive dendritic cell maturation phenotype that allows continued class II MHC synthesis and antigen processing

    PubMed Central

    Simmons, Daimon P.; Wearsch, Pamela A.; Canaday, David H.; Meyerson, Howard J.; Liu, Yi C.; Wang, Ying; Boom, W. Henry; Harding, Clifford V.

    2012-01-01

    Microbial molecules or cytokines can stimulate dendritic cell (DC) maturation, which involves DC migration to lymph nodes and enhanced presentation of Ag to launch T cell responses. Microbial Toll-like receptor (TLR) agonists are the most studied inducers of DC maturation, but type I interferon (IFN-I) also promotes DC maturation. In response to TLR stimulation, DC maturation involves a burst of Ag processing with enhanced expression of peptide-MHC-II complexes and co-stimulator molecules. Subsequently, MHC-II synthesis and expression in intracellular vacuolar compartments is inhibited, decreasing Ag processing function. This limits presentation to a cohort of Ags kinetically associated with the maturation stimulus and excludes presentation of Ags subsequently experienced by the DC. In contrast, our studies show that IFN-I enhances DC expression of MHC-II and co-stimulatory molecules without a concomitant inhibition of subsequent MHC-II synthesis and Ag processing. Expression of mRNA for MHC-II and the transcription factor CIITA is inhibited in DCs treated with TLR agonists but maintained in cells treated with IFN-I. Following stimulation with IFN-I, MHC-II expression is increased on the plasma membrane but is also maintained in intracellular vacuolar compartments, consistent with sustained Ag processing function. These findings suggest that IFN-I drives a distinctive DC maturation program that enhances Ag presentation to T cells without a shutdown of Ag processing, allowing continued sampling of Ags for presentation. PMID:22371391

  12. The predisposition to type 1 diabetes linked to the human leukocyte antigen complex includes at least one non-class II gene.

    PubMed Central

    Lie, B A; Todd, J A; Pociot, F; Nerup, J; Akselsen, H E; Joner, G; Dahl-Jørgensen, K; Rønningen, K S; Thorsby, E; Undlien, D E

    1999-01-01

    The human leukocyte antigen (HLA) complex, encompassing 3.5 Mb of DNA from the centromeric HLA-DPB2 locus to the telomeric HLA-F locus on chromosome 6p21, encodes a major part of the genetic predisposition to develop type 1 diabetes, designated "IDDM1." A primary role for allelic variation of the class II HLA-DRB1, HLA-DQA1, and HLA-DQB1 loci has been established. However, studies of animals and humans have indicated that other, unmapped, major histocompatibility complex (MHC)-linked genes are participating in IDDM1. The strong linkage disequilibrium between genes in this complex makes mapping a difficult task. In the present paper, we report on the approach we have devised to circumvent the confounding effects of disequilibrium between class II alleles and alleles at other MHC loci. We have scanned 12 Mb of the MHC and flanking chromosome regions with microsatellite polymorphisms and analyzed the transmission of these marker alleles to diabetic probands from parents who were homozygous for the alleles of the HLA-DRB1, HLA-DQA1, and HLA-DQB1 genes. Our analysis, using three independent family sets, suggests the presence of an additional type I diabetes gene (or genes). This approach is useful for the analysis of other loci linked to common diseases, to verify if a candidate polymorphism can explain all of the association of a region or if the association is due to two or more loci in linkage disequilibrium with each other. PMID:10053014

  13. Human leukocyte antigen-DRB1 class II genes in Mexican Amerindian Mazahuas: genes and languages do not correlate.

    PubMed

    Arnaiz-Villena, Antonio; Abd-El-Fatah, Sedeka; Granados-Silvestre, María Angeles; Parga-Lozano, Carlos; Gómez-Prieto, Pablo; Rey, Diego; Areces, Cristina; Peñaranda, Patricia; Menjívar, Martha; Rodríguez-Pérez, José Manuel; Granados, Julio; Vargas-Alarcón, Gilberto

    2011-01-01

    The major histocompatibility complex genes are located on the short arm of the human sixth chromosome; they are highly polymorphic and therefore have been very advantageous in population genetic studies. A Mazahua group established in North Mexico State and also in nearby Michoacan state in the rainy mountain highlands (Mexico) was studied for their human leukocyte antigen (HLA)-DRB1 alleles. The relationship with other Amerindians and worldwide populations was studied by using 14,996 chromosomes from 75 different populations and calculating neighbor-joining dendrograms and correspondence multidimensional values. Five principal HLA allele frequencies were found in our group: DRB1*0802 (the most frequent one in this population), DRB1*0407, DRB1*0403, DRB1*0101, and DRB1*1406. Both genetic distances and correspondence analyses clearly show that our Mazahua group is genetically close to some of the most ancient groups living in Mexico (Mayos, Zapotecans, Tennek) and South American Amerindians. Amerindians remain as a group apart from the rest of the world. The results analyzing the HLA-DR locus suggest that Mazahua language (Otomangue) does not correlate with those of the most closely HLA-correlated ethnic groups. The present data may be useful for future transplantation programs, HLA and disease diagnosis, and pharmacogenetic studies.

  14. Clozapine-induced agranulocytosis in schizophrenic Caucasians: confirming clues for associations with human leukocyte class I and II antigens.

    PubMed

    Dettling, M; Cascorbi, I; Opgen-Rhein, C; Schaub, R

    2007-10-01

    Clozapine-induced agranulocytosis (CA) is still among the least understood adverse drug reactions in psychopharmacology. In particular, its genetic background is far from being clarified. Within the framework of a case-control study, we performed human leukocyte antigen (HLA) genotyping and haplotype analyses in 42 non-Jewish Caucasian schizophrenic patients (N=42) suffering from CA and 75 non-Jewish Caucasian schizophrenic patients treated with clozapine without developing CA. While controlling for age (P<0.0001) and sex (P=0.835), testing of the alleles from both HLA-loci resulted in borderline results for Cw2 (P=0.085, odds ratio (OR)=0.36, 95% confidence interval (CI): 0.08-1.23), Cw7 (P=0.058, OR=2.0, 95% CI: 0.87-4.63) and DRB5*0201 (P=0.005, adjusted OR=22.15). For haplotype analysis, we obtained significant association results with CA for the two-locus haplotypes HLA-Cw-B (P=0.022) and HLA-DRB5-DRB4 (P=0.050), and for the three-locus haplotype HLA-Cw-B-DRB5 (P=0.030). The complex nature of CA implies that many genes might play a role, but currently, only HLA associations with CA are identified as clinically relevant.

  15. Point mutations in or near the antigen-binding groove of HLA-DR3 implicate class II-associated invariant chain peptide affinity as a constraint on MHC class II polymorphism.

    PubMed

    Doebele, Robert C; Pashine, Achal; Liu, Wendy; Zaller, Dennis M; Belmares, Michael; Busch, Robert; Mellins, Elizabeth D

    2003-05-01

    During maturation of MHC II molecules, newly synthesized and assembled complexes of MHC II alphabeta dimers with invariant chain (Ii) are targeted to endosomes, where Ii is proteolyzed, leaving remnant class II-associated Ii peptides (CLIP) in the MHC II peptide binding groove. CLIP must be released, usually with assistance from the endosomal MHC II peptide exchange factor, HLA-DM, before MHC II molecules can bind endosomal peptides. Structural factors that control rates of CLIP release remain poorly understood, although peptide side chain-MHC II specificity pocket interactions and MHC II polymorphism are important. Here we report that mutations betaS11F, betaS13Y, betaQ70R, betaK71E, betaK71N, and betaR74Q, which map to the P4 and P6 pockets of the groove of HLA-DR3 molecules, as well as alphaG20E adjacent to the groove, are associated with elevated CLIP in cells. Most of these mutations increase the resistance of CLIP-DR3 complexes to dissociation by SDS. In vitro, the groove mutations increase the stability of CLIP-DR3 complexes to dissociation. Dissociation rates in the presence of DM, as well as coimmunoprecipitation of some mutant DR3 molecules with DM, are also diminished. The profound phenotypes associated with some of these point mutations suggest that the need to maintain efficient CLIP release represents a constraint on naturally occurring MHC II polymorphism.

  16. Human leucocyte antigens class II allele and haplotype association with Type 1 Diabetes in Madeira Island (Portugal).

    PubMed

    Spínola, H; Lemos, A; Couto, A R; Parreira, B; Soares, M; Dutra, I; Bruges-Armas, J; Brehm, A; Abreu, S

    2017-08-20

    This study confirms for Madeira Island (Portugal) population the Type 1 Diabetes (T1D) susceptible and protective Human leucocyte antigens (HLA) markers previously reported in other populations and adds some local specificities. Among the strongest T1D HLA associations, stands out, as susceptible, the alleles DRB1*04:05 (OR = 7.3), DQB1*03:02 (OR = 6.1) and DQA1*03:03 (OR = 4.5), as well as the haplotypes DRB1*04:05-DQA1*03:03-DQB1*03:02 (OR = 100.9) and DRB1*04:04-DQA1*03:01-DQB1*03:02 (OR = 22.1), and DQB1*06:02 (OR = 0.07) and DRB1*15:01-DQA1*01:02-DQB1*06:02 (OR = 0.04) as protective. HLA-DQA1 positive for Arginine at position 52 (Arg52) (OR = 15.2) and HLA-DQB1 negative for Aspartic acid at the position 57 (Asp57) (OR = 9.0) alleles appear to be important genetic markers for T1D susceptibility, with higher odds ratio values than any single allele and than most of the haplotypes. Genotypes generated by the association of markers Arg52 DQA1 positive and Asp57 DQB1 negative increase T1D susceptibility much more than one would expected by a simple additive effect of those markers separately (OR = 26.9). This study also confirms an increased risk for DRB1*04/DRB1*03 heterozygote genotypes (OR = 16.8) and also a DRB1*04-DQA1*03:01-DQB1*03:02 haplotype susceptibility dependent on the DRB1*04 allele (DRB1*04:01, OR = 7.9; DRB1*04:02, OR = 3.2; DRB1*04:04, OR = 22.1). © 2017 John Wiley & Sons Ltd.

  17. Association of swine leukocyte antigen class II haplotypes and immune-related traits in a swine line selected for resistance to mycoplasmal pneumonia.

    PubMed

    Ando, Asako; Shigenari, Atsuko; Kojima-Shibata, Chihiro; Nakajoh, Mitsuru; Suzuki, Keiichi; Kitagawa, Hitoshi; Shiina, Takashi; Inoko, Hidetoshi; Uenishi, Hirohide

    2016-10-01

    By selective breeding for five generations, a Landrace line has been recently established to improve resistance to mycoplasmal pneumonia of swine (MPS), daily gain (DG), back fat thickness (BF), and plasma cortisol concentrations (COR). To clarify the involvement of swine leukocyte antigen (SLA) polymorphisms in the selection process, we investigated possible associations of 11 SLA-class II haplotypes with selected traits or immune parameters. Pigs with the low-resolution SLA haplotype Lr-0.23 or Lr-0.13, which increased in frequency with the passage of generations, had less severe pathological lesions of MPS, increased leukocyte phagocytic activity, and higher white blood cell counts. In contrast, Lr-0.12 and Lr-0.2, which decreased in subsequent generations, were weakly associated with more severe pathological lesions of MPS. Therefore, in the studied Landrace line, the Lr-0.23 and Lr-0.13 haplotypes are potentially useful genetic markers for selecting and breeding animals with less severe pathological lesions of MPS. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. A DNA vaccine encoding foot-and-mouth disease virus B and T-cell epitopes targeted to class II swine leukocyte antigens protects pigs against viral challenge.

    PubMed

    Borrego, Belén; Argilaguet, Jordi M; Pérez-Martín, Eva; Dominguez, Javier; Pérez-Filgueira, Mariano; Escribano, José M; Sobrino, Francisco; Rodriguez, Fernando

    2011-11-01

    Development of efficient and safer vaccines against foot-and-mouth disease virus (FMDV) is a must. Previous results obtained in our laboratory have demonstrated that DNA vaccines encoding B and T cell epitopes from type C FMDV, efficiently controlled virus replication in mice, while they did not protect against FMDV challenge in pigs, one of the FMDV natural hosts. The main finding of this work is the ability to improve the protection afforded in swine using a new DNA-vaccine prototype (pCMV-APCH1BTT), encoding FMDV B and T-cell epitopes fused to the single-chain variable fragment of the 1F12 mouse monoclonal antibody that recognizes Class-II Swine Leukocyte antigens. Half of the DNA-immunized pigs were fully protected upon viral challenge, while the remaining animals were partially protected, showing a delayed, shorter and milder disease than control pigs. Full protection in a given vaccinated-pig correlated with the induction of specific IFNγ-secreting T-cells, detectable prior to FMDV-challenge, together with a rapid development of neutralizing antibodies after viral challenge, pointing towards the relevance that both arms of the immune response can play in protection. Our results open new avenues for developing future FMDV subunit vaccines.

  19. [Antibodies to infliximab and antigens HLA I-II class as the witnesses of immune response to the biological treatment of inflammatory bowel disease].

    PubMed

    Sagynbaeva, V É; Lazebnik, L B; Kniazev, O V; Efremov, L I

    2011-01-01

    Despite combination therapy with immunosuppressive agents, 32.5% of patients with IBD showed the formation of antibodies to infliximab. Simultaneous study of the concentration of the drug (infliximab), TNF-alpha and antibodies to it in the blood serum allows to judge not only on the effectiveness of anticytokine therapy, but also on the advisability of further conducting therapy. Elevated levels of AINF may lead to infusion reactions, reducing the effectiveness and duration of response to this therapy. Transplantation of MSCs reduces the level of antibodies to infliximab, but in 2 (5%) patients noticed a gradual increase of these antibodies. After infliximab infusion from 4 to 8 weeks the level in serum increased up to 45 mg/ml and higher, further serological concentration of infliximab is gradually reduced and then falls below the-horn. High concentrations of infliximab (> 45 mkg/ml) in blood samples at combined immunosuppressive therapy (infliximab + glucocorticoids + cytotoxic agents) should be considered as a sign of potential complications. The absence of antibodies to antigens of HLA I and class II after systemic transplantation of allogeneic mesenchymal stromal cells (MSCs) of bone marrow demonstrates not only the effectiveness but also the safety of transplantation of allogeneic MSCs, in relation with that the special selection of donors for transplantation of allogeneic MSCs is not required.

  20. Genetic control of T cell responsiveness to the Friend murine leukemia virus envelope antigen. Identification of class II loci of the H-2 as immune response genes

    PubMed Central

    1988-01-01

    T cells primed specifically for the envelope glycoprotein of Friend murine leukemia helper virus (F-MuLV) were prepared by immunizing mice with a recombinant vaccinia virus that expressed the entire env gene of F-MuLV. Significant proliferative responses of F-MuLV envelope- specific, H-2a/b T cells were observed when the T cells were stimulated with antigen-pulsed peritoneal exudate cells (PEC) having the b allele at the K, A beta, A alpha, and E beta loci of the H-2. On the other hand, PEC having only the kappa allele at these loci did not induce the envelope-specific T cell proliferation, even when the PEC had the b allele at the E alpha, S, or D loci. F-MuLV envelope-specific proliferation of H-2a/b T cells under the stimulation of antigen- pulsed, H-2a/b PEC was specifically blocked with anti-I-Ab and anti-I- Ek mAbs but not with anti-Kb, anti-Kk, or anti-I-Ak mAbs. Moreover, (B10.MBR x A/WySn)F1 mice that have the b allele only at the K locus but not in I-A subregion were nonresponders to the envelope glycoprotein, and the bm12 mutation at the A beta locus completely abolished the T cell responsiveness to this antigen. These results indicate that proliferative T cells recognize a limited number of epitopes on F-MuLV envelope protein in the context of I-Ab, hybrid I- Ak/b, and/or hybrid I-Ek/b class II MHC molecules but fail to recognize the same envelope protein in the context of I-Ak or I-Ek molecules. This influence of the H-2I region on T cell recognition of the envelope glycoprotein appeared to control in vivo induction of protective immunity against Friend virus complex after immunization with the vaccinia-F-MuLV env vaccine. Thus, these results provide, for the first time, direct evidence for Ir gene-controlled responder/nonresponder phenotypes influencing the immune response to a pathogenic virus of mice. PMID:3141552

  1. Effect of human leukocyte antigen class I and II alleles on hepatitis C viral load among chronic hepatitis C patients in Southern Taiwan.

    PubMed

    Tseng, Kuo-Chih; Tseng, Chih-Wei; Hsieh, Yu-Hsi; Chang, Chin-Kuo; Lai, Ning-Sheng; Hung, Tsung-Hsing; Chang, Ting-Tsung

    2013-08-01

    The viral load of hepatitis C virus (HCV) in chronic hepatitis C patients affects clinical outcomes and response to interferon treatment. Various factors may be involved in determining the viral load, including host genetic factors. The aim of this study was to investigate the relationship between HCV viral load and human leukocyte antigen (HLA) class I and class II alleles. One hundred and six HCV RNA positive subjects were enrolled, and viral load was measured. HLA-A, -B, -C, -DR, and -DQ loci were determined by sequence-based genotyping. Univariate analysis indicated that HLA-B(*)40 and HLA-C(*)07 alleles had significantly higher HCV RNA levels (P<0.05). Patients with the HLA-C(*)15 allele exhibited a trend toward a lower HCV viral load (P=0.06). After controlling for confounding factors, multivariate analysis revealed that only HLA-C(*)15 allele was identified as a significant determinant for HCV-RNA level (slope=-0.91, 95% CI: -1.58, -0.24; Holm's P<0.01). Patients expressing the HLA-C(*)15 allele had significantly lower HCV RNA levels. HCV genotype 1 was significantly associated with high HCV RNA levels (P<0.05 by Mann-Whitney U test). In conclusion, HLA-C(*)15 is an important host immunogenetic factor with an inverse association to HCV viral load in CHC patients in Taiwan. HCV genotype 1 is the viral factor that associated with high viral load. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  2. Identification of bovine leukocyte antigen class II haplotypes associated with variations in bovine leukemia virus proviral load in Japanese Black cattle.

    PubMed

    Miyasaka, T; Takeshima, S-n; Jimba, M; Matsumoto, Y; Kobayashi, N; Matsuhashi, T; Sentsui, H; Aida, Y

    2013-02-01

    Bovine leukemia virus (BLV) is the etiological agent of enzootic bovine leukosis, which is the most common neoplastic disease of cattle. Bovine leukocyte antigen (BoLA) is strongly involved in the subclinical progression of BLV infections. Recent studies show that the BoLA-DRB3 gene might play a direct role in controlling the number of BLV-infected peripheral B lymphocytes in vivo in Holstein cattle. However, the specific BoLA class II allele and DRB3-DQA1 haplotypes determining the BLV proviral load in Japanese Black cattle are yet to be identified. In this study, we focused on the association of BLV proviral load and polymorphism of BoLA class II in Japanese Black cattle. We genotyped 186 BLV-infected, clinically normal cattle for BoLA-DRB3 and BoLA-DQA1 using a polymerase chain reaction-sequence-based typing method. BoLA-DRB3*0902 and BoLA-DRB3*1101 were associated with a low proviral load (LPVL), and BoLA-DRB3*1601 was associated with a high proviral load (HPVL). Furthermore, BoLA-DQA1*0204 and BoLA-DQA1*10012 were related to LPVL and HPVL, respectively. Furthermore, we confirmed the correlation between the DRB3-DQA1 haplotype and BLV proviral load. Two haplotypes, namely 0902B or C (DRB3*0902-DQA1*0204) and 1101A (DRB3*1101-DQA1*10011), were associated with a low BLV proviral load, whereas one haplotype 1601B (DRB3*1601-DQA1*10012) was associated with a high BLV proviral load. We conclude that resistance is a dominant trait and susceptibility is a recessive trait. Additionally, resistant alleles were common between Japanese Black and Holstein cattle, and susceptible alleles differed. This is the first report to identify an association between the DRB3-DQA1 haplotype and variations in BLV proviral load. © 2012 John Wiley & Sons A/S.

  3. Detection of aberrant transcription of major histocompatibility complex class II antigen presentation genes in chronic lymphocytic leukaemia identifies HLA-DOA mRNA as a prognostic factor for survival.

    PubMed

    Souwer, Yuri; Chamuleau, Martine E D; van de Loosdrecht, Arjan A; Tolosa, Eva; Jorritsma, Tineke; Muris, Jettie J F; Dinnissen-van Poppel, Marion J; Snel, Sander N; van de Corput, Lisette; Ossenkoppele, Gert J; Meijer, Chris J L M; Neefjes, Jacques J; Marieke van Ham, S

    2009-05-01

    In human B cells, effective major histocompatibility complex (MHC) class II-antigen presentation depends not only on MHC class II, but also on the invariant chain (CD74 or Ii), HLA-DM (DM) and HLA-DO (DO), the chaperones regulating the antigen loading process of MHC class II molecules. We analysed immediate ex vivo expression of HLA-DR (DR), CD74, DM and DO in B cell chronic lymphocytic leukaemia (B-CLL). Real-time reverse transcription polymerase chain reaction demonstrated a highly significant upregulation of DRA, CD74, DMB, DOA and DOB mRNA in purified malignant cells compared to B cells from healthy donors. The increased mRNA levels were not translated into enhanced protein levels but could reflect aberrant transcriptional regulation. Indeed, upregulation of DRA, DMB, DOA and DOB mRNA correlated with enhanced expression of class II transactivator (CIITA). In-depth analysis of the various CIITA transcripts demonstrated a significant increased activity of the interferon-gamma-inducible promoter CIITA-PIV in B-CLL. Comparison of the aberrant mRNA levels with clinical outcome identified DOA mRNA as a prognostic indicator for survival. Multivariate analysis revealed that the prognostic value of DOA mRNA was independent of the mutational status of the IGHV genes. Thus, aberrant transcription of DOA forms a novel and additional prognostic indicator for survival in B-CLL.

  4. Dog leucocyte antigen class II diversity and relationships among indigenous dogs of the island nations of Indonesia (Bali), Australia and New Guinea.

    PubMed

    Runstadler, J A; Angles, J M; Pedersen, N C

    2006-11-01

    The genetic polymorphism at the dog leucocyte antigen (DLA) class II loci DQA1, DQB1 and DRB1 was studied in a large genetically diverse population of feral and wild-type dogs from the large island nations of Indonesia (Bali), Australia and New Guinea (Bali street dog, dingo and New Guinea singing dog, respectively). Sequence-based typing (SBT) of the hypervariable region of DLA-DRB1, -DQA1 and -DQB1 alleles was used to determine genetic diversity. No new DQA1 alleles were recognized among the three dog populations, but five novel DLA-DRB1 and 2 novel DLA-DQB1 allele sequences were detected. Additional unknown alleles were postulated to exist in Bali street dogs, as indicated by the large percentage of individuals (15%-33%) that had indeterminate DRB1, DQA1 and DQB1 alleles by SBT. All three groups of dogs possessed alleles that were relatively uncommon in conventional purebreds. The New Guinea singing dog and dingo shared alleles that were not present in the Bali street dogs. These findings suggested that the dingo was more closely related to indigenous dogs from New Guinea. Feral dog populations, in particular large ones such as that of Bali, show genetic diversity that existed prior to phenotypic selection for breeds originating from their respective regions. This diversity needs to be identified and maintained in the face of progressive Westernization. These populations deserve further study as potential model populations for the evolution of major histocompatibility complex alleles, for the study of canine genetic diversity, for the development of dog breeds and for studies on the comigration of ancestral human and dog populations.

  5. Studies on associations between human leukocyte antigen (HLA) class II alleles and antiphospholipid antibodies in Danish and Czech women with recurrent miscarriages.

    PubMed

    Christiansen, O B; Ulcova-Gallova, Z; Mohapeloa, H; Krauz, V

    1998-12-01

    Autoantibody production is commonly associated with particular HLA class II phenotypes. The aim of the present study was to investigate whether the presence of antiphospholipid (APL) antibodies and other autoantibodies in women with unexplained recurrent miscarriage was associated with particular human leukocyte antigen (HLA)-DR or -DQ alleles or linked epitopes which have previously been reported as being associated with the recurrent miscarriage syndrome or the presence of APL. In a total of 123 Danish and Czech women with recurrent miscarriage, serum was investigated for six different APL antibodies including anticardiolipin (ACL) antibody. Antinuclear antibodies (ANA), anti-zona pellucida antibodies and anti-sperm antibodies were also investigated. The women were HLA-DR and -DQ typed by DNA-based methods. The frequency of HLA-DR phenotypes did not differ significantly between APL antibody positive recurrent miscarriage patients and APL antibody negative recurrent miscarriage patients or healthy controls. Among ACL antibody positive recurrent miscarriage patients, significantly more were positive for the HLA-DR3 phenotype and negative for the HLA-DR2 phenotypes compared with healthy controls (P < 0.05). Among ANA positive recurrent miscarriage women, 55% carried the HLA-DR3 phenotype compared with 28% of ANA negative patients (P < 0.05) and 21% of healthy controls (P < 0.002). In conclusion, among recurrent miscarriage women, the HLA-DR3 phenotypes seem to predispose to formation of ACL antibodies and ANA. The association between APL antibodies and particular HLA alleles and HLA-linked epitopes reported in studies of patients with lupus erythematosus (e.g. HLA-DR7 and -DR4) could not be confirmed in patients with recurrent miscarriage.

  6. The Association between Human Leukocyte Antigen Class II DR3-DQ2 Haplotype and Type 1 Diabetes in Children of the East Azerbaijan State of Iran.

    PubMed

    Mansoori Derakhshan, Sima; Zeinali Sehrig, Fatemeh; Sohrabi, Nasrin; Shiva, Siamak; Baradaran, Behzad; Shekari Khaniani, Mahmoud

    2015-09-01

    Type 1 diabetes mellitus (T1D) is an autoimmune disease. Several associations between human leukocyte antigen (HLA) complex and T1D were found in various populations. Associations with various HLA types depend on the investigated populations. However, such associations have not yet been investigated in the East Azerbaijan state of Iran with Turkish ethnicity. The aims of the current study was to describe T1D genetic susceptibility conferred by HLA class II alleles (DRB1*0301, DQA1*0501 and DQB1*0201) and to determine haplotype frequencies among T1D patients. This study was a case-control study. The number of samples was determined using the Cochran formula. Eighty unrelated T1D patients, including 42 (52.5%) females and 38 (47.5%) males, were randomly recruited from the East Azerbaijan state of Iran. Typing of HLA was performed by polymerase chain reaction-sequence-specific priming (PCR-SSP) on DNA extracted from peripheral blood mononuclear cells of 80 unrelated patients and 80 unrelated healthy control donors, who were selected randomly. For haplotype analysis, the logistic regression model was performed that allows joint estimation of Single-nucleotide polymorphisms (SNPs) via haplotypes. The frequency of drb1*0301 (82.5% vs. 11.3%), dqa1*0501 (82.5% vs. 36.3%) and dqb1*0201 (81.3% vs. 35%) were significantly higher among patients compared with that of healthy subjects. Our investigation demonstrated that there is a highly significant association between the studied alleles and T1D. It can be construed that haplotype HLA-DR3-DQ2 has a very modest effect with respect to the risk of T1D.

  7. Antigen-Specific Signaling by a Soluble, Dimeric Peptide/Major Histocompatibility Complex Class II/Fc Chimera Leading to T Helper Cell Type 2 Differentiation

    PubMed Central

    Casares, Sofia; Zong, Cong S.; Radu, Dorel L.; Miller, Alexander; Bona, Constantin A.; Brumeanu, Teodor-Doru

    1999-01-01

    Interaction between a T cell receptor (TCR) and various ligands, i.e., anti-TCR antibodies, superantigens, peptides, or altered peptide ligands in the context of major histocompatibility complex (MHC) molecules can trigger different T helper cell (Th) effector functions. Herein, we studied the T cell response induced by a soluble, dimeric peptide/MHC class II chimera, namely hemagglutinin (HA)110-120/I-Edαβ/Fcγ2a (DEF). We have previously demonstrated that the soluble DEF molecule binds stably and specifically to HA110-120–specific TCRs expressed by a T cell hybridoma. Administration of DEF in vivo induced differentiation of resting and activated peptide-specific T cells toward a Th2 response, as indicated by the increase of interleukin (IL)-4, IL-10, and specific immunoglobulin (Ig)G1 antibodies and decrease of IL-2, specific IgG2a antibodies, and cytotoxic T lymphocyte activity. In contrast to HA110-120 peptide presented by the DEF molecule to T cells, the nominal synthetic peptide induced a predominant Th1 response, and the PR8 virus–derived HA110-120 peptides induced a mixed Th1/Th2 response. Independent of antigen processing, soluble DEF was almost 2 logs more potent in stimulating cognate T cells than the nominal peptide. Polarization of cognate T cells toward the Th2 response occurred upon interaction of soluble DEF with TCR and CD4 molecules followed by early activation of p56lck and ZAP-70 tyrosine kinases, and negative signaling of the signal transducer and activator of transcription (STAT)4 pathway of Th1 differentiation. DEF-like molecules may provide a new tool to study the mechanisms of signaling toward Th2 differentiation and may also provide a potential immunotherapeutic approach to modulate autoreactive T cells toward protective Th2 immune responses. PMID:10449525

  8. Shark Class II Invariant Chain Reveals Ancient Conserved Relationships with Cathepsins and MHC Class II

    PubMed Central

    Criscitiello, Michael F.; Ohta, Yuko; Eubanks, Jeannine O.; Chen, Patricia L.; Flajnik, Martin F.

    2011-01-01

    The invariant chain (Ii) is the critical third chain required for the MHC class II heterodimer to be properly guided through the cell, loaded with peptide, and expressed on the surface of antigen presenting cells. Here, we report the isolation of the nurse shark Ii gene, and the comparative analysis of Ii splice variants, expression, genomic organization, predicted structure, and function throughout vertebrate evolution. Alternative splicing to yield Ii with and without the putative protease-protective, thyroglobulin-like domain is as ancient as the MHC-based adaptive immune system, as our analyses in shark and lizard further show conservation of this mechanism in all vertebrate classes except bony fish. Remarkable coordinate expression of Ii and class II was found in shark tissues. Conserved Ii residues and cathepsin L orthologs suggest their long co-evolution in the antigen presentation pathway, and genomic analyses suggest 450 million years of conserved Ii exon/intron structure. Other than an extended linker preceding the thyroglobulin-like domain in cartilaginous fish, the Ii gene and protein are predicted to have largely similar physiology from shark to man. Duplicated Ii genes found only in teleosts appear to have become sub-functionalized, as one form is predicted to play the same role as that mediated by Ii mRNA alternative splicing in all other vertebrate classes. No Ii homologs or potential ancestors of any of the functional Ii domains were found in the jawless fish or lower chordates. PMID:21996610

  9. Shark class II invariant chain reveals ancient conserved relationships with cathepsins and MHC class II.

    PubMed

    Criscitiello, Michael F; Ohta, Yuko; Graham, Matthew D; Eubanks, Jeannine O; Chen, Patricia L; Flajnik, Martin F

    2012-03-01

    The invariant chain (Ii) is the critical third chain required for the MHC class II heterodimer to be properly guided through the cell, loaded with peptide, and expressed on the surface of antigen presenting cells. Here, we report the isolation of the nurse shark Ii gene, and the comparative analysis of Ii splice variants, expression, genomic organization, predicted structure, and function throughout vertebrate evolution. Alternative splicing to yield Ii with and without the putative protease-protective, thyroglobulin-like domain is as ancient as the MHC-based adaptive immune system, as our analyses in shark and lizard further show conservation of this mechanism in all vertebrate classes except bony fish. Remarkable coordinate expression of Ii and class II was found in shark tissues. Conserved Ii residues and cathepsin L orthologs suggest their long co-evolution in the antigen presentation pathway, and genomic analyses suggest 450 million years of conserved Ii exon/intron structure. Other than an extended linker preceding the thyroglobulin-like domain in cartilaginous fish, the Ii gene and protein are predicted to have largely similar physiology from shark to man. Duplicated Ii genes found only in teleosts appear to have become sub-functionalized, as one form is predicted to play the same role as that mediated by Ii mRNA alternative splicing in all other vertebrate classes. No Ii homologs or potential ancestors of any of the functional Ii domains were found in the jawless fish or lower chordates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Immunization with a peptide containing MHC class I and II epitopes derived from the tumor antigen SIM2 induces an effective CD4 and CD8 T-cell response.

    PubMed

    Kissick, Haydn T; Sanda, Martin G; Dunn, Laura K; Arredouani, Mohamed S

    2014-01-01

    Here, we sought to determine whether peptide vaccines designed harbor both class I as well as class II restricted antigenic motifs could concurrently induce CD4 and CD8 T cell activation against autologous tumor antigens. Based on our prior genome-wide interrogation of human prostate cancer tissues to identify genes over-expressed in cancer and absent in the periphery, we targeted SIM2 as a prototype autologous tumor antigen for these studies. Using humanized transgenic mice we found that the 9aa HLA-A*0201 epitope, SIM2(237-245), was effective at inducing an antigen specific response against SIM2-expressing prostate cancer cell line, PC3. Immunization with a multi-epitope peptide harboring both MHC-I and MHC-II restricted epitopes induced an IFN-γ response in CD8 T cells to the HLA-A*0201-restricted SIM2(237-245) epitope, and an IL-2 response by CD4 T cells to the SIM2(240-254) epitope. This peptide was also effective at inducing CD8+ T-cells that responded specifically to SIM2-expressing tumor cells. Collectively, the data presented in this study suggest that a single peptide containing multiple SIM2 epitopes can be used to induce both a CD4 and CD8 T cell response, providing a peptide-based vaccine formulation for potential use in immunotherapy of various cancers.

  11. Enhanced Detection of Antigen-Specific CD4+ T Cells Using Altered Peptide Flanking Residue Peptide–MHC Class II Multimers

    PubMed Central

    Holland, Christopher J.; Dolton, Garry; Scurr, Martin; Ladell, Kristin; Schauenburg, Andrea J.; Miners, Kelly; Madura, Florian; Sewell, Andrew K.; Price, David A.

    2015-01-01

    Fluorochrome-conjugated peptide–MHC (pMHC) class I multimers are staple components of the immunologist’s toolbox, enabling reliable quantification and analysis of Ag-specific CD8+ T cells irrespective of functional outputs. In contrast, widespread use of the equivalent pMHC class II (pMHC-II) reagents has been hindered by intrinsically weaker TCR affinities for pMHC-II, a lack of cooperative binding between the TCR and CD4 coreceptor, and a low frequency of Ag-specific CD4+ T cell populations in the peripheral blood. In this study, we show that peptide flanking regions, extending beyond the central nonamer core of MHC-II–bound peptides, can enhance TCR–pMHC-II binding and T cell activation without loss of specificity. Consistent with these findings, pMHC-II multimers incorporating peptide flanking residue modifications proved superior for the ex vivo detection, characterization, and manipulation of Ag-specific CD4+ T cells, highlighting an unappreciated feature of TCR–pMHC-II interactions. PMID:26553072

  12. Enhancement of antigen acquisition by dendritic cells and MHC class II-restricted epitope presentation to CD4+ T cells using VP22 DNA vaccine vectors that promote intercellular spreading following initial transfection.

    PubMed

    Mwangi, Waithaka; Brown, Wendy C; Splitter, Gary A; Zhuang, Yan; Kegerreis, Kimberly; Palmer, Guy H

    2005-08-01

    Induction of immune responses against microbial antigens using DNA is an attractive strategy to mimic the immunity induced by live vaccines. Although DNA vaccines are efficacious in murine models, the requirement for multiple immunizations using high doses in outbred animals and humans has hindered deployment. This requirement is, in part, a result of poor vaccine spreading and suboptimal DC transfection efficiency. Incorporation of a signal that directs intercellular spreading of a DNA-encoded antigen is proposed to mimic live vaccine spreading and increase dendritic cell (DC) presentation. Bovine herpes virus 1 tegument protein, BVP22, is capable of trafficking to surrounding cells. To test the hypothesis that BVP22 enhances spreading and antigen presentation to CD4+ T cells, a DNA construct containing BVP22, fused in-frame to a sequence encoding a T cell epitope of Anaplasma marginale, was generated. A construct with reversed BVP22 sequence served as a negative control. Immunocytometric analysis of transfected primary keratinocytes, human embryonic kidney 293, COS-7, and Chinese hamster ovary cells showed that BVP22 enhanced intercellular spreading by > or = 150-fold. Flow cytometric analysis of antigen-presenting cells (APCs) positively selected from cocultures of transfected cells and APCs showed that 5% of test APCs were antigen-positive, compared with 0.6% of control APCs. Antigen-specific CD4+ T cell proliferation demonstrated that BVP22 enhanced DC antigen presentation by > or = 20-fold. This first report of the ability of BVP22 to increase DNA-encoded antigen acquisition by DCs and macrophages, with subsequent enhancement of major histocompatibility complex class II-restricted CD4+ T cell responses, supports incorporating a spreading motif in a DNA vaccine to target CD4+ T cell-dependent immunity in outbred animals.

  13. Associations among human leukocyte antigen (HLA) class II DQ variants, bacterial sexually transmitted diseases, endometritis, and fertility among women with clinical pelvic inflammatory disease.

    PubMed

    Ness, Roberta B; Brunham, Robert C; Shen, Caixia; Bass, Debra C

    2004-05-01

    We investigated associations between HLA class II DQ alleles, chlamydial and gonococcal cervicitis, endometritis, and infertility among women with pelvic inflammatory disease (PID). Ninety-two women with clinical signs and symptoms of mild-to-moderate PID, enrolled in the PEACH Study, were evaluated. For all HLA class II DQ alleles with a prevalence of 10% or greater in the population, we assessed demographics, cervical infections, endometrial pathology, and fertility outcomes. Chlamydial cervicitis, gonococcal cervicitis, endometritis, and infertility were all more common among women carrying the DQA *0301 allele after adjustment for race. Endometritis and infertility were somewhat less common (or pregnancy more common) among women carrying the DQA *0501 and DQB *0402 alleles. Among women with signs and symptoms of PID, carriage of the DQA *0301, DQA *0501, and DQB *0402 alleles altered the occurrence of lower genital tract infection, upper genital tract inflammation, and infertility.

  14. The correlation between ovomucoid-derived peptides, human leucocyte antigen class II molecules and T cell receptor-complementarity determining region 3 compositions in patients with egg-white allergy.

    PubMed

    Suzuki, K; Inoue, R; Sakaguchi, H; Aoki, M; Kato, Z; Kaneko, H; Matsushita, S; Kondo, N

    2002-08-01

    Food allergies are more prevalent in children, due to the immature gastrointestinal epithelial membrane barrier allowing more proteins through the barrier and into circulation. Ovomucoid (OM) is one of the major allergens that is found in egg white. The aim of this study was to determine T cell epitopes, antigen-presenting human leucocyte antigen (HLA) class II molecules of the T cell lines (TCLs) and T cell clones (TCCs), and complementarity determining region (CDR) 3 loops of the T cell receptor (TCR) alpha and beta chains of the TCCs specific to OM. We established TCLs and TCCs specific to OM from peripheral blood mononuclear cells (PBMCs) of four atopic patients with egg-white allergy using a mixture of a panel of overlapping synthetic peptides corresponding to the amino acid sequence of the entire OM. We identified the T cell epitopes by antigen-induced proliferative responses, antigen-presenting molecules using allogeneic PBMCs and CDR3 loops of the TCR alpha and beta chains by cloning and sequence analysis. The TCLs and TCCs responded to seven different peptides, and their antigen-presenting molecules were different from each other. Sequence analysis of the TCR alpha and beta gene usage of the TCCs showed marked heterogeneity, and the usage of the CDR3 loop of the TCCs involved heterogenous amino acid residues. Interestingly, TCCs 'IH3.3' and 'YT6.1' recognized the same OM peptides, and had the same TCR Vbeta-Jbeta gene usage. Considering that peptide motifs bind to HLA class II molecules, the electrically charged residue (positive or negative) on the CDR3alpha and the CDR3beta loops of TCR of TCC may form ionic bonds with a charged residue on the HLA class II molecules-peptide complex. TCCs that have the same TCR gene usage were established from patients who had shown similar hypersensitivity-type, indicating that antigen recognition by a specific TCR is closely associated with the characteristics of each patient's symptoms.

  15. Decreased expression of MHC class II and cathepsin E in dendritic cells might contribute to impaired induction of antigen-specific T cell response in NC/Nga mice.

    PubMed

    Sakai, Tohru; Shuto, Emi; Taki, Tomoyo; Imamura, Honami; Kioka, Miku; Nakamoto, Akiko; Mizoguchi, Seiji; Amano, Shouko; Kawano, Yukari; Nakamoto, Mariko; Tsutumi, Rie; Hosaka, Toshio

    2012-01-01

    NC/Nga (NC) mice are an animal model for human atopic dermatitis. We found that induction of antigen (Ag)-specific T cell response is diminished in ovalbumin (OVA)-immunized NC mice. Ability of Ag presentation in NC mouse dendritic cells (DCs) was significantly weaker than that in BALB/c and DBA/2 mouse DCs. Expression levels of MHC class II molecules and cathepsin E in NC mouse DCs were significantly lower that those in BALB/c and DBA/2 mouse DCs. These results indicate that low expression levels of MHC class II and cathepsin E might contribute to the defect in induction of Ag-specific T cells in NC mice.

  16. 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

    SciTech Connect

    Henderson, Kate N.; Reid, Hugh H.; Borg, Natalie A.; Broughton, Sophie E.; Huyton, Trevor; Anderson, Robert P.; McCluskey, James; Rossjohn, Jamie

    2007-12-01

    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.

  17. Transforming growth factors type beta 1 and beta 2 suppress rat astrocyte autoantigen presentation and antagonize hyperinduction of class II major histocompatibility complex antigen expression by interferon-gamma and tumor necrosis factor-alpha.

    PubMed

    Schluesener, H J

    1990-04-01

    The transforming growth factors (TGF) type beta 1 and beta 2 are regulatory cytokines strongly affecting rat astrocyte immune functions. Both cytokines suppressed presentation of autoantigen by astrocytes: highly encephalitogenic T cells cocultured with TGF-beta-treated astrocytes in the presence of myelin basic protein did not become activated to transfer experimental allergic encephalomyelitis, a central nervous system (CNS) autoimmune disease. Furthermore, TGF-beta 1 and -beta 2 antagonized hyperinduction of astrocyte major histocompatibility complex (MHC) class II antigen expression by interferon-gamma and tumor necrosis factor-alpha. Thus, TGF-beta might be a potential regulator of CNS inflammation.

  18. Kaposi's Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen Inhibits Major Histocompatibility Complex Class II Expression by Disrupting Enhanceosome Assembly through Binding with the Regulatory Factor X Complex

    PubMed Central

    Thakker, Suhani; Purushothaman, Pravinkumar; Gupta, Namrata; Challa, Shanthan; Cai, Qiliang

    2015-01-01

    ABSTRACT Major histocompatibility complex class II (MHC-II) molecules play a central role in adaptive antiviral immunity by presenting viral peptides to CD4+ T cells. Due to their key role in adaptive immunity, many viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV), have evolved multiple strategies to inhibit the MHC-II antigen presentation pathway. The expression of MHC-II, which is controlled mainly at the level of transcription, is strictly dependent upon the binding of the class II transactivator (CIITA) to the highly conserved promoters of all MHC-II genes. The recruitment of CIITA to MHC-II promoters requires its direct interactions with a preassembled MHC-II enhanceosome consisting of cyclic AMP response element-binding protein (CREB) and nuclear factor Y (NF-Y) complex and regulatory factor X (RFX) complex proteins. Here, we show that KSHV-encoded latency-associated nuclear antigen (LANA) disrupts the association of CIITA with the MHC-II enhanceosome by binding to the components of the RFX complex. Our data show that LANA is capable of binding to all three components of the RFX complex, RFX-associated protein (RFXAP), RFX5, and RFX-associated ankyrin-containing protein (RFXANK), in vivo but binds more strongly with the RFXAP component in in vitro binding assays. Levels of MHC-II proteins were significantly reduced in KSHV-infected as well as LANA-expressing B cells. Additionally, the expression of LANA in a luciferase promoter reporter assay showed reduced HLA-DRA promoter activity in a dose-dependent manner. Chromatin immunoprecipitation assays showed that LANA binds to the MHC-II promoter along with RFX proteins and that the overexpression of LANA disrupts the association of CIITA with the MHC-II promoter. These assays led to the conclusion that the interaction of LANA with RFX proteins interferes with the recruitment of CIITA to MHC-II promoters, resulting in an inhibition of MHC-II gene expression. Thus, the data presented here identify

  19. An immunocytochemical study of pulpal responses to cavity preparation by laser ablation in rat molars by using antibodies to heat shock protein (Hsp) 25 and class II MHC antigen.

    PubMed

    Suzuki, Takeshi; Nomura, Shuichi; Maeda, Takeyasu; Ohshima, Hayato

    2004-03-01

    Initial responses of odontoblasts and immunocompetent cells to cavity preparation by laser ablation were investigated in rat molars. In untreated control teeth, intense heat shock protein (Hsp) 25 immunoreactivity was found in the cell bodies of odontoblasts, whereas cells immunopositive for the class II major histocompatibility complex (MHC) antigen were predominantly located beneath the odontoblast layer in the dental pulp. Cavity preparation caused the destruction of the odontoblast layer and the shift of most class-II-MHC-positive cells from the pulp-dentin border toward the pulp core at the affected site. Twelve hours after cavity preparation, numerous class-II-MHC-positive cells appeared along the pulp-dentin border and extended their processes deep into the exposed dentinal tubules, but subsequently disappeared from the pulp-dentin border together with Hsp-25-immunopositive cells by 24 h after the operation. By 3-5 days postoperation, distinct abscess formation consisting of polymorphonuclear leukocytes was found in the dental pulp. The penetration of masses of oral bacteria was recognizable in the dentinal tubules beneath the prepared cavity. These findings indicate that cavity preparation by laser ablation induces remarkable inflammation by continuous bacterial infections via dentinal tubules in this experimental model, thereby delaying pulpal regeneration.

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

    PubMed

    Denzin, Lisa K; Cresswell, Peter

    2013-01-01

    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.

  1. Comprehensive and high-resolution typing of swine leukocyte antigen DQA from genomic DNA and determination of 25 new SLA class II haplotypes.

    PubMed

    Le, M T; Choi, H; Choi, M-K; Nguyen, D T; Kim, J-H; Seo, H G; Cha, S-Y; Seo, K; Chun, T; Schook, L B; Park, C

    2012-12-01

    We previously reported the development of genomic-DNA-based high-resolution genotyping methods for SLA-DQB1 and DRB1. Here, we report the successful typing of SLA-DQA using similar methodological principles. We designed a method for comprehensive genotyping of SLA-DQA using intronic sequence information of SLA-DQA exon 2 that we had obtained from 12 animals with different SLA-DQB1 genotypes. We expanded our typing to 76 selected animals with diverse DQB1 and DRB1 genotypes, 140 random animals from 7 pig breeds, and 3 wild boars. This resulted in the identification of 17 DQA alleles with 49 genotypes. Two new alleles were identified from wild boars. Combine with SLA-DQB1, and DRB1 typing results, we identified 34 SLA class II haplotypes including 25 that were previously unreported. © 2012 John Wiley & Sons A/S.

  2. A recombinant single-chain human class II MHC molecule (HLA-DR1) as a covalently linked heterotrimer of alpha chain, beta chain, and antigenic peptide, with immunogenicity in vitro and reduced affinity for bacterial superantigens.

    PubMed

    Zhu, X; Bavari, S; Ulrich, R; Sadegh-Nasseri, S; Ferrone, S; McHugh, L; Mage, M

    1997-08-01

    Major histocompatibility complex (MHC) class II molecules bind to numerous peptides and display these on the cell surface for T cell recognition. In a given immune response, receptors on T cells recognize antigenic peptides that are a minor population of MHC class II-bound peptides. To control which peptides are presented to T cells, it may be desirable to use recombinant MHC molecules with covalently bound antigenic peptides. To study T cell responses to such homogeneous peptide-MHC complexes, we engineered an HLA-DR1 cDNA coding for influenza hemagglutinin, influenza matrix, or HIV p24 gag peptides covalently attached via a peptide spacer to the N terminus of the DR1 beta chain. Co-transfection with DR alpha cDNA into mouse L cells resulted in surface expression of HLA-DR1 molecules that reacted with monoclonal antibodies (mAb) specific for correctly folded HLA-DR epitopes. This suggested that the spacer and peptide did not alter expression or folding of the molecule. We then engineered an additional peptide spacer between the C terminus of a truncated beta chain (without transmembrane or cytoplasmic domains) and the N terminus of full-length DR alpha chain. Transfection of this cDNA into mouse L cells resulted in surface expression of the entire covalently linked heterotrimer of peptide, beta chain, and alpha chain with the expected molecular mass of approximately 66 kDa. These single-chain HLA-DR1 molecules reacted with mAb specific for correctly folded HLA-DR epitopes, and identified one mAb with [MHC + peptide] specificity. Affinity-purified soluble secreted single-chain molecules with truncated alpha chain moved in electrophoresis as compact class II MHC dimers. Cell surface two-chain or single-chain HLA-DR1 molecules with a covalent HA peptide stimulated HLA-DR1-restricted HA-specific T cells. They were immunogenic in vitro for peripheral blood mononuclear cells. The two-chain and single-chain HLA-DR1 molecules with covalent HA peptide had reduced binding

  3. Distinct T cell interactions with HLA class II tetramers characterize a spectrum of TCR affinities in the human antigen-specific T cell response.

    PubMed

    Reichstetter, S; Ettinger, R A; Liu, A W; Gebe, J A; Nepom, G T; Kwok, W W

    2000-12-15

    The polyclonal nature of T cells expanding in an ongoing immune response results in a range of disparate affinities and activation potential. Recently developed human class II tetramers provide a means to analyze this diversity by direct characterization of the trimolecular TCR-peptide-MHC interaction in live cells. Two HSV-2 VP16(369-379)-specific, DQA1*0102/DQB1*0602 (DQ0602)-restricted T cell clones were compared by means of T cell proliferation assay and HLA-DQ0602 tetramer staining. These two clones were obtained from the same subject, but show different TCR gene usage. Clone 48 was 10-fold more sensitive to VP16(369-379) peptide stimulation than clone 5 as assayed by proliferation assays, correlating with differences in MHC tetramer binding. Clone 48 gave positive staining with the DQ0602/VP16(369-379) tetramer at either 23 or 37 degrees C. Weak staining was also observed at 4 degrees C. Clone 5 showed weaker staining compared with clone 48 at 37 degrees C, and no staining was observed at 23 degrees C or on ice. Receptor internalization was not required for positive staining. Competitive binding indicates that the cell surface TCR of clone 48 has higher affinity for the DQ0602/VP16(369-379) complex than clone 5. The higher binding affinity of clone 48 for the peptide-MHC complex also correlates with a slower dissociation rate compared with clone 5.

  4. Quantitative analysis of peptide-MHC class II interaction.

    PubMed

    Fleckenstein, B; Jung, G; Wiesmüller, K H

    1999-12-01

    The tremendous progress in the field of basic immunology and immunochemistry made in the last decade has significantly advanced our understanding of antigen processing and presentation by MHC class I and II proteins. In this review different techniques to study peptide interaction with MHC class II molecules are summarized and their impact on the elucidation of quantitative parameters, like affinities or kinetic data, is discussed. A recently introduced method based on synthetic combinatorial peptide libraries allows to quantify the binding contribution of each amino acid residue in a class II ligand and is presented in more detail. As this knowledge is fundamental for current investigations in modern medicine, e.g. for novel immune system based therapy concepts, further aspects like the design of new high affinity MHC class II ligands and the prediction of peptide antigens are discussed.

  5. Increased expression of CD54, CD18, MHC class II molecules, and proliferating cell nuclear antigen in acute puromycin aminonucleoside nephrosis.

    PubMed

    Fernandez, Lucas; Romero, Maritza; Rincón, Jaimar; Mosquera, Jesús

    2003-01-01

    Cellular infiltration to renal tissues is an important feature during acute puromycin aminonucleoside nephrosis (PAN) in rats. The mechanisms responsible for this infiltration are poorly understood. To elucidate the participation of adhesion molecules in PAN, nephrosis was induced in rats by intraperitoneal puromycin aminonucleoside injection. Controls represent animals injected with a 0.9% saline solution. ICAM-1 (intercellular adhesion molecule 1), CD18 (beta chain of lymphocyte-function-associated antigen), LCA (leukocyte common antigen), ED1 (monocyte/macrophage marker), and proliferating cell nuclear antigen expressions were evaluated in renal tissues 1, 2, and 7 weeks after injection. Frozen sections from PAN rat kidneys showed increased expressions of ICAM-1 and its ligand, and these findings were associated with increased levels of LCA+ and ED1+ cells in glomerulus and interstitium. The kinetics of leukocyte infiltration was similar to the kinetics of ICAM-1 expression: high values at week 2 which returned to normal values at week 7. Increased glomerular and interstitial proliferative activities (proliferating cell nulear antigen positive cells) were also found at week 2 of nephrosis. There was a correlation between ICAM-1 expression and numbers of LCA+ and ED1+ cells and between numbers of LCA+ cells and proliferating cells in glomerulus and interstitium. Correlations between glomerular and tubular ICAM-1 expression, interstitial leukocyte infiltration, and glomerular, interstitial, and tubular proliferative activities with the proteinuria were also observed during the nephrotic phase. In addition, increased lymphocyte binding to PAN renal tissues was observed, and this binding was diminished by anti-LFA-1beta monoclonal antibody pretreatment of lymphocytes. A similar result was found with anti-ICAM-1 monoclonal antibody pretreatment of renal tissues. Our results suggest that increased expression of ICAM-1 and proliferative activity could be important

  6. Ii Chain Controls the Transport of Major Histocompatibility Complex Class II Molecules to and from Lysosomes

    PubMed Central

    Brachet, Valérie; Raposo, Graça; Amigorena, Sebastian; Mellman, Ira

    1997-01-01

    Major histocompatibility complex class II molecules are synthesized as a nonameric complex consisting of three αβ dimers associated with a trimer of invariant (Ii) chains. After exiting the TGN, a targeting signal in the Ii chain cytoplasmic domain directs the complex to endosomes where Ii chain is proteolytically processed and removed, allowing class II molecules to bind antigenic peptides before reaching the cell surface. Ii chain dissociation and peptide binding are thought to occur in one or more postendosomal sites related either to endosomes (designated CIIV) or to lysosomes (designated MIIC). We now find that in addition to initially targeting αβ dimers to endosomes, Ii chain regulates the subsequent transport of class II molecules. Under normal conditions, murine A20 B cells transport all of their newly synthesized class II I-Ab αβ dimers to the plasma membrane with little if any reaching lysosomal compartments. Inhibition of Ii processing by the cysteine/serine protease inhibitor leupeptin, however, blocked transport to the cell surface and caused a dramatic but selective accumulation of I-Ab class II molecules in lysosomes. In leupeptin, I-Ab dimers formed stable complexes with a 10-kD NH2-terminal Ii chain fragment (Ii-p10), normally a transient intermediate in Ii chain processing. Upon removal of leupeptin, Ii-p10 was degraded and released, I-Ab dimers bound antigenic peptides, and the peptide-loaded dimers were transported slowly from lysosomes to the plasma membrane. Our results suggest that alterations in the rate or efficiency of Ii chain processing can alter the postendosomal sorting of class II molecules, resulting in the increased accumulation of αβ dimers in lysosome-like MIIC. Thus, simple differences in Ii chain processing may account for the highly variable amounts of class II found in lysosomal compartments of different cell types or at different developmental stages. PMID:9105036

  7. IL-6 down-regulates HLA class II expression and IL-12 production of human dendritic cells to impair activation of antigen-specific CD4(+) T cells.

    PubMed

    Ohno, Yosuke; Kitamura, Hidemitsu; Takahashi, Norihiko; Ohtake, Junya; Kaneumi, Shun; Sumida, Kentaro; Homma, Shigenori; Kawamura, Hideki; Minagawa, Nozomi; Shibasaki, Susumu; Taketomi, Akinobu

    2016-02-01

    Immunosuppression in tumor microenvironments critically affects the success of cancer immunotherapy. Here, we focused on the role of interleukin (IL)-6/signal transducer and activator of transcription (STAT3) signaling cascade in immune regulation by human dendritic cells (DCs). IL-6-conditioned monocyte-derived DCs (MoDCs) impaired the presenting ability of cancer-related antigens. Interferon (IFN)-γ production attenuated by CD4(+) T cells co-cultured with IL-6-conditioned MoDCs corresponded with decreased DC IL-12p70 production. Human leukocyte antigen (HLA)-DR and CD86 expression was significantly reduced in CD11b(+)CD11c(+) cells obtained from peripheral blood mononuclear cells (PBMCs) of healthy donors by IL-6 treatment and was STAT3 dependent. Arginase-1 (ARG1), lysosomal protease, cathepsin L (CTSL), and cyclooxygenase-2 (COX2) were involved in the reduction of surface HLA-DR expression. Gene expressions of ARG1, CTSL, COX2, and IL6 were higher in tumor-infiltrating CD11b(+)CD11c(+) cells compared with PBMCs isolated from colorectal cancer patients. Expression of surface HLA-DR and CD86 on CD11b(+)CD11c(+) cells was down-regulated, and T cell-stimulating ability was attenuated compared with PBMCs, suggesting that an immunosuppressive phenotype might be induced by IL-6, ARG1, CTSL, and COX2 in tumor sites of colorectal cancer patients. There was a relationship between HLA-DR expression levels in tumor tissues and the size of CD4(+) T and CD8(+) T cell compartments. Our findings indicate that IL-6 causes a dysfunction in human DCs that activates cancer antigen-specific Th cells, suggesting that blocking the IL-6/STAT3 signaling pathway might be a promising strategy to improve cancer immunotherapy.

  8. A new antigenic marker specifically labels a subpopulation of the class II Kenyon cells in the brain of the European honeybee Apis mellifera.

    PubMed

    Watanabe, Takayuki; Kubo, Takeo

    2015-01-01

    The mushroom bodies are the higher-order integration center in the insect brain and are involved in higher brain functions such as learning and memory. In the social hymenopteran insects such as honeybees, the mushroom bodies are the prominent brain structures. The mushroom bodies are composed of lobed neuropils formed by thousands of parallel-projecting axons of intrinsic neurons, and the lobes are divided into parallel subdivisions. In the present paper, we report a new antigenic marker to label a single layer in the vertical lobes of the European honeybee Apis mellifera. In the brain of A. mellifera, a monoclonal antibody (mAb) 15C3, which was originally developed against an insect ecdysone receptor (EcR) protein, immunolabels a single layer of the vertical lobes that correspond to the most dorsal layer of the γ-lobe. The 15C3 mAb recognizes a single ~200 kDa protein expressed in the adult honeybee brain. In addition, the 15C3 mAb immunoreactivity was also observed in the lobes of the developing pupal mushroom bodies. Since γ-lobe is well known to their extensive reorganization that occurs during metamorphosis in Drosophila, the novel antigenic marker for the honeybee γ-lobe allows us to investigate morphological changes of the mushroom bodies during metamorphosis.

  9. Double loading of dendritic cell MHC class I and MHC class II with an AML antigen repertoire enhances correlates of T-cell immunity in vitro via amplification of T-cell help.

    PubMed

    Decker, William K; Xing, Dongxia; Li, Sufang; Robinson, Simon N; Yang, Hong; Yao, Xin; Segall, Harry; McMannis, John D; Komanduri, Krishna V; Champlin, Richard E; Shpall, Elizabeth J

    2006-04-12

    Therapeutic vaccination with dendritic cells presenting tumor-specific antigens is now recognized as an important investigational therapy for the treatment of neoplastic disease. Dendritic cell cross-presentation is credited with the ability of tumor lysate-loaded dendritic cells to prime both CD4 and CD8-specific T-lymphocyte responses, enabling the generation of cancer specific CTL activity without the loading of the classical MHC class I compartment. Recently, however, several reports have raised doubts as to the efficiency of cross-presentation as a mechanism for CTL priming in vivo. To examine this issue, we have doubly-loaded human dendritic cells with both AML-specific tumor lysate and AML-specific tumor mRNA. Our results show that these doubly-loaded dendritic cells can mediate superior primary, recall, and effector lytic responses in vitro in comparison to those of dendritic cells loaded with either tumor lysate or tumor mRNA alone. Enhanced recall responses appeared to be influenced by CD40/CD40L signaling, underscoring the importance of T-cell help in the generation and perpetuation of the adaptive immune response.

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

    PubMed Central

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

    2016-01-01

    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-Ed 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

  11. Impact of MHC Class II Incompatibility on Localization of Mononuclear Cell Infiltrates to the Bronchiolar Compartment of Orthotopic Lung Allografts

    PubMed Central

    Nakashima, Shinji; Soong, T. Rinda; Fox-Talbot, Karen; Qian, Zhiping; Rahimi, Salma; Wasowska, Barbara A.; Rohde, Charles A.; Chen, Sabrina; Garcia, Joe G.N.; Baldwin, William M.

    2005-01-01

    Chronic pathological changes in transplanted lungs are unique because they center on the airways. We examined the relative role of MHC class I and II antigens in causing bronchial pathology in orthotopic lung transplants to rats maintained on cyclosporin A (CsA). Transplants mismatched for MHC class II antigens had significantly more peri-bronchiolar infiltrates than MHC class I incompatible transplants. No significant increase in infiltrates was found in lung transplants incompatible for MHC class I plus II antigens compared to MHC class II antigens alone. Immunohistochemistry demonstrated that MHC class II antigen expression was confined to macrophages in MHC class I incompatible transplants, but was upregulated on bronchial epithelium in transplants with MHC class II incompatibilities. Vascular endothelium was notably devoid of MHC class II antigen expression in all transplants. However, both peri-bronchial and peri-vascular infiltrates were frequently cuffed by alveolar macrophages and type II pneumocytes that expressed MHC class II antigens. PCR analysis demonstrated that IFN-γ and regulated on activation, normal T cells expressed and secreted (RANTES) were upregulated in MHC class II incompatible transplants. Thus, MHC class II incompatible orthotopic lung transplants in rats maintained on CsA immunosuppression undergo a bronchiolcentric upregulation of alloantigens. PMID:15760392

  12. Viral immune evasion: Lessons in MHC class I antigen presentation.

    PubMed

    van de Weijer, Michael L; Luteijn, Rutger D; Wiertz, Emmanuel J H J

    2015-03-01

    The MHC class I antigen presentation pathway enables cells infected with intracellular pathogens to signal the presence of the invader to the immune system. Cytotoxic T lymphocytes are able to eliminate the infected cells through recognition of pathogen-derived peptides presented by MHC class I molecules at the cell surface. In the course of evolution, many viruses have acquired inhibitors that target essential stages of the MHC class I antigen presentation pathway. Studies on these immune evasion proteins reveal fascinating strategies used by viruses to elude the immune system. Viral immunoevasins also constitute great research tools that facilitate functional studies on the MHC class I antigen presentation pathway, allowing the investigation of less well understood routes, such as TAP-independent antigen presentation and cross-presentation of exogenous proteins. Viral immunoevasins have also helped to unravel more general cellular processes. For instance, basic principles of ER-associated protein degradation via the ubiquitin-proteasome pathway have been resolved using virus-induced degradation of MHC class I as a model. This review highlights how viral immunoevasins have increased our understanding of MHC class I-restricted antigen presentation.

  13. The use of reference strand-mediated conformational analysis for the study of cheetah (Acinonyx jubatus) feline leucocyte antigen class II DRB polymorphisms.

    PubMed

    Drake, G J C; Kennedy, L J; Auty, H K; Ryvar, R; Ollier, W E R; Kitchener, A C; Freeman, A R; Radford, A D

    2004-01-01

    There is now considerable evidence to suggest the cheetah (Acinonyx jubatus) has limited genetic diversity. However, the extent of this and its significance to the fitness of the cheetah population, both in the wild and captivity, is the subject of some debate. This reflects the difficulty associated with establishing a direct link between low variability at biologically significant loci and deleterious aspects of phenotype in this, and other, species. Attempts to study one such region, the feline leucocyte antigen (FLA), are hampered by a general reliance on cloning and sequencing which is expensive, labour-intensive, subject to PCR artefact and always likely to underestimate true variability. In this study we have applied reference strand-mediated conformational analysis (RSCA) to determine the FLA-DRB phenotypes of 25 cheetahs. This technique was rapid, repeatable and less prone to polymerase chain reaction (PCR)-induced sequence artefacts associated with cloning. Individual cheetahs were shown to have up to three FLA-DRB genes. A total of five alleles were identified (DRB*ha14-17 and DRB*gd01) distributed among four genotypes. Fifteen cheetahs were DRB*ha14/ha15/ha16/ha17, three were DRB*ha15/ha16/ha17, six were DRB*ha14/ha16/ha17 and one was DRB*ha14/ha15/ha16/ha17/gd01. Sequence analysis of DRB*gd01 suggested it was a recombinant of DRB*ha16 and DRB*ha17. Generation of new alleles is difficult to document, and the clear demonstration of such an event is unusual. This study confirms further the limited genetic variability of the cheetah at a biologically significant region. RSCA will facilitate large-scale studies that will be needed to correlate genetic diversity at such loci with population fitness in the cheetah and other species.

  14. Contrasting evolutionary histories of MHC class I and class II loci in grouse--effects of selection and gene conversion.

    PubMed

    Minias, P; Bateson, Z W; Whittingham, L A; Johnson, J A; Oyler-McCance, S; Dunn, P O

    2016-05-01

    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.

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

    PubMed Central

    Minias, P; Bateson, Z W; Whittingham, L A; Johnson, J A; Oyler-McCance, S; Dunn, P O

    2016-01-01

    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. PMID:26860199

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

    USGS Publications Warehouse

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

    2016-01-01

    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.

  17. Redirecting soluble antigen for MHC class I cross-presentation during phagocytosis.

    PubMed

    Hari, Aswin; Ganguly, Anutosh; Mu, Libing; Davis, Shevaun P; Stenner, Melanie D; Lam, Raymond; Munro, Fay; Namet, Inana; Alghamdi, Enaam; Fürstenhaupt, Tobias; Dong, Wei; Detampel, Pascal; Shen, Lian Jun; Amrein, Matthias W; Yates, Robin M; Shi, Yan

    2015-02-01

    Peptides presented by MHC class I molecules are mostly derived from proteins synthesized by the antigen-presenting cell itself, while peptides presented by MHC class II molecules are predominantly from materials acquired by endocytosis. External antigens can also be presented by MHC class I molecules in a process referred to as cross-presentation. Here, we report that mouse dendritic cell (DC) engagement to a phagocytic target alters endocytic processing and inhibits the proteolytic activities. During phagocytosis, endosome maturation is delayed, shows less progression toward the lysosome, and the endocytosed soluble antigen is targeted for MHC class I cross-presentation. The antigen processing in these arrested endosomes is under the control of NAPDH oxidase associated ROS. We also show that cathepsin S is responsible for the generation of the MHC class I epitope. Taken together, our results suggest that in addition to solid structure uptake, DC phagocytosis simultaneously modifies the kinetics of endosomal trafficking and maturation. As a consequence, external soluble antigens are targeted into the MHC class I cross-presentation pathway.

  18. Redirecting soluble antigen for MHC class I cross-presentation during phagocytosis

    PubMed Central

    Hari, Aswin; Ganguly, Anutosh; Mu, Libing; Davis, Shevaun P.; Stenner, Melanie D.; Lam, Raymond; Munro, Fay; Namet, Inana; Alghamdi, Enaam; Fürstenhaupt, Tobias; Dong, Wei; Detampel, Pascal; Shen, Lian Jun; Amrein, Matthias W.; Yates, Robin M.; Shi, Yan

    2014-01-01

    Peptides presented by MHC class I molecules are derived mostly from proteins synthesized by the antigen-presenting cell itself, while peptides presented by MHC class II molecules are derived predominantly from materials acquired by endocytosis. External antigens can also be presented by MHC class I molecules in a process referred to as cross-presentation. We report that mouse dendritic cell engagement of a phagocytic target alters endocytic processing and inhibits their proteolytic activities. During phagocytosis, endosome maturation is delayed, shows less progression towards the lysosome, and the endocytosed soluble antigen is targeted for MHC class I cross-presentation. The antigen processing in these arrested endosomes is under the control of NAPDH oxidase associated ROS. We also show that cathepsin S is responsible for the generation of the MHC class I epitope. Our results suggest that in addition to solid structure uptake, DC phagocytosis simultaneously modifies the kinetics of endosomal trafficking and maturation. As a consequence, external soluble antigens are targeted into the MHC class I cross-presentation pathway. PMID:25378230

  19. Depletion of CD4+CD25+ regulatory T cells exacerbates sodium iodide-induced experimental autoimmune thyroiditis in human leucocyte antigen DR3 (DRB1*0301) transgenic class II-knock-out non-obese diabetic mice.

    PubMed

    Flynn, J C; Meroueh, C; Snower, D P; David, C S; Kong, Y M

    2007-03-01

    Both genetic and environmental factors contribute to autoimmune disease development. Previously, we evaluated genetic factors in a humanized mouse model of Hashimoto's thyroiditis (HT) by immunizing human leucocyte antigen DR3 (HLA-DR3) and HLA-DQ8 transgenic class II-knock-out non-obese diabetic (NOD) mice. DR3+ mice were susceptible to experimental autoimmune thyroiditis (EAT) induction by both mouse thyroglobulin (mTg) and human (h) Tg, while DQ8+ mice were weakly susceptible only to hTg. As one environmental factor associated with HT and tested in non-transgenic models is increased sodium iodide (NaI) intake, we examined the susceptibility of DR3+ and/or DQ8+ mice to NaI-induced disease. Mice were treated for 8 weeks with NaI in the drinking water. At 0 x 05% NaI, 23% of DR3+, 0% of DQ8+ and 20% of DR3+DQ8+ mice had thyroid destruction. No spleen cell proliferation to mTg was observed. Most mice had undetectable anti-mTg antibodies, but those with low antibody levels usually had thyroiditis. At 0.3% NaI, a higher percentage of DR3+ and DR3+DQ8+ mice developed destructive thyroiditis, but it was not statistically significant. However, when DR3+ mice had been depleted of CD4+CD25+ regulatory T cells prior to NaI treatment, destructive thyroiditis (68%) and serum anti-mTg antibodies were exacerbated further. The presence of DQ8 molecules does not alter the susceptibility of DR3+DQ8+ mice to NaI-induced thyroiditis, similar to earlier findings with mTg-induced EAT. Susceptibility of DR3+ mice to NaI-induced EAT, in both the presence and absence of regulatory T cells, demonstrates the usefulness of HLA class II transgenic mice in evaluating the roles of environmental factors and immune dysregulation in autoimmune thyroid disease.

  20. Regulation of MHC II and CD1 antigen presentation: from ubiquity to security.

    PubMed

    Gelin, Catherine; Sloma, Ivan; Charron, Dominique; Mooney, Nuala

    2009-02-01

    MHC class II and CD1-mediated antigen presentation on various APCs [B cells, monocytes, and dendritic cells (DC)] are subject to at least three distinct levels of regulation. The first one concerns the expression and structure of the antigen-presenting molecules; the second is based on the extracellular environment and signals of danger detected. However, a third level of regulation, which has been largely overlooked, is determined by lateral associations between antigen-presenting molecules and other proteins, their localization in specialized microdomains within the plasma membrane, and their trafficking pathways. This review focuses on features common to MHC II and CD1 molecules in their ability to activate specific T lymphocytes with the objective of addressing one basic question: What are the mechanisms regulating antigen presentation by MHC II and CD1 molecules within the same cell? Recent studies in immature DC, where MHC II and CD1 are coexpressed, suggest that the invariant chain (Ii) regulates antigen presentation by either protein. Ii could therefore favor MHC II or CD1 antigen presentation and thereby discriminate between antigens.

  1. Secretory granules of mast cells accumulate mature and immature MHC class II molecules.

    PubMed

    Vincent-Schneider, H; Théry, C; Mazzeo, D; Tenza, D; Raposo, G; Bonnerot, C

    2001-01-01

    Bone marrow-derived mast cells as well as dendritic cells, macrophages and B lymphocytes express major histocompatibility complex (MHC) class II molecules. In mast cells, the majority of MHC class II molecules reside in intracellular cell type-specific compartments, secretory granules. To understand the molecular basis for the localisation of MHC class II molecules in secretory granules, MHC class II molecules were expressed, together with the invariant chain, in the mast cell line, RBL-2H3. Using electron and confocal microscopy, we observed that in RBL-2H3 cells, mature and immature class II molecules accumulate in secretory granules. Two particular features of class II transport accounted for this intracellular localization: first, a large fraction of newly synthesized MHC class II molecules remained associated with invariant chain fragments. This defect, resulting in a slower rate of MHC class II maturation, was ascribed to a low cathepsin S activity. Second, although a small fraction of class II dimers matured (i.e. became free of invariant chain), allowing their association with antigenic peptides, they were retained in secretory granules. As a consequence of this intracellular localization, cell surface expression of class II molecules was strongly increased by cell activation stimuli which induced the release of the contents of secretory granules. Our results suggest that antigen presentation, and thereby antigen specific T cell stimulation, are regulated in mast cells by stimuli which induce mast cell activation.

  2. Astrocyte cytolysis by MHC class II-specific mouse T cell clones.

    PubMed

    Reder, A T; Lascola, C D; Flanders, S A; Maimone, D; Jensen, M A; Skias, D D; Lancki, D W

    1993-08-01

    The brain is "immunologically privileged," in part because class I and II MHC antigens are not normally present on glia or neurons. However, under certain conditions such as transplantation, glial cells express MHC proteins at levels sufficient for glia to become targets of immune responses. Cultured astrocytes expressing very low levels of MHC class I protein are killed efficiently by MHC class I antigen-specific CTL. Mouse brain allografts, however, are rejected by CD4+ T cells that are likely to be class II MHC-specific. The level of expression of MHC class II antigen needed to trigger specific killing of astrocytes by CD4+ T cells, independent of exogenous antigen, has not been studied. We examined the role of glial class II MHC in the lysis of cultured neonatal mouse astrocytes by an alloreactive murine CD4+ CTL alone. IFN-gamma induced functionally relevant increases in MHC class II antigen on target cells. Astrocytes were lysed by the CD4+ clone only when class II MHC antigens reached levels readily detectable by flow cytometry. MHC class II expression and lysis increased when astrocytes were coincubated with IFN-gamma and TNF-alpha. Conversely, lysis decreased when class II expression was downregulated by IFN-alpha/beta or dbcAMP. Cytolysis by CD4+ clones was blocked by antibodies to CD4 and LFA-1 on T cells, and to ICAM-1 and class II molecules on astrocytes. The role of LFA-1 in CD4+ cell-mediated lysis was greater than that of LFA-1/ICAM-1 in CD8+ T cell-mediated lysis. CD4+ cells may lyse activated astrocytes when the immune privilege of the brain is compromised as in transplantation, tumors, and inflammatory diseases.

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

    PubMed Central

    2012-01-01

    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. PMID:23031405

  4. Archaebacterial class I and class II aldolases from extreme halophiles

    NASA Astrophysics Data System (ADS)

    Alterkar, Wijaya; Dhar, Nenoo M.

    1988-03-01

    Both, class I (Schiff-base forming) and class II (metal requiring) fructose biphosphate aldolases were found to be distributed among halophilic archaebacteria. The aldolase activity fromHalobacterium halobium, H. salinarium, H. cutirubrum, H. mediterranei andH. volcanii exhibited properties of a bacterial class II aldolase as it was metal-dependent for activity and therefore inhibited by EDTA. In contrast, aldolase fromH. saccharovorum, Halobacterium R-113, H. vallismortis andHalobacterium CH-1 formed a Schiff-base intermediate with the substrate and therefore resembled to eukaryotic class I type. The type of aldolase did not vary by changes in the growth medium.

  5. Archaebacterial class I and class II aldolases from extreme halophiles.

    PubMed

    Altekar, W; Dhar, N M

    1988-01-01

    Both, class I (Schiff-base forming) and class II (metal requiring) fructose biphosphate aldolases were found to be distributed among halophilic archaebacteria. The aldolase activity from Halobacteriium halobium, H. salinarium, H. cutirubrum, H. mediterranei and H. volcanii exhibited properties of a bacterial class II aldolase as it was metal-dependent for activity and therefore inhibited by EDTA. In contrast, aldolase from H. saccharovorum, Halobacterium R-113, H. vallismortis and Halobacterium CH-1 formed a Schiff-base intermediate with the substrate and therefore resembled to eukaryotic class I type. The type of aldolase did not vary by changes in the growth medium.

  6. HLA-DM induces CLIP dissociation from MHC class II alpha beta dimers and facilitates peptide loading.

    PubMed

    Denzin, L K; Cresswell, P

    1995-07-14

    Human leukocyte antigen DM (HLA-DM) molecules are structurally related to classical MHC class II molecules and reside in the lysosome-like compartment where class II-restricted antigen processing is thought to occur. Mutant cell lines lacking HLA-DM are defective in antigen processing and accumulate class II molecules associated with a nested set of invariant chain-derived peptides (class II-associated invariant chain peptides, CLIP). Here we show that HLA-DM catalyzes the dissociation of CLIP from MHC class II-CLIP complexes in vitro and facilitates the binding of antigenic peptides. The reaction has an acidic pH optimum, consistent with its occurrence in a lysosome-like compartment in vivo. Antibody blocking experiments suggest that a transient interaction between HLA-DM and the MHC class II-CLIP complex is required.

  7. The antigens - Volume VII

    SciTech Connect

    Sela, M. )

    1987-01-01

    This book contains four chapters. They are: Ir Genes: Antigen-Specific Genetic Regulation of the Immune Response; Molecular Genetics of Class II (Ia) Antigens; Antigen-Specific T Cell Clones and T Cell Factors; and Infection and Autoimmunity.

  8. Early failure of Class II resin composite versus Class II amalgam restorations placed by dental students.

    PubMed

    Overton, J D; Sullivan, Diane J

    2012-03-01

    Using the information from remake request slips in a dental school's predoctoral clinic, we examined the short-term survival of Class II resin composite restorations versus Class II dental amalgam restorations. In the student clinic, resin composite is used in approximately 58 percent of Class II restorations placed, and dental amalgam is used in the remaining 42 percent. In the period examined, Class II resin composite restorations were ten times more likely to be replaced at no cost to the patient than Class II dental amalgam restorations. A total of eighty-four resin composite restorations and six amalgam restorations were replaced due to an identified failure.

  9. Delivery of a viral antigen to the class I processing and presentation pathway by Listeria monocytogenes

    PubMed Central

    1994-01-01

    Listeria monocytogenes is a facultative intracellular pathogen that grows in the cytoplasm of infected host cells. We examined the capacity of L. monocytogenes to introduce influenza nucleoprotein (NP) into the class I pathway of antigen presentation both in vitro and in vivo. Recombinant L. monocytogenes secreting a fusion of listeriolysin O and NP (LLO-NP) targeted infected cells for lysis by NP-specific class I- restricted cytotoxic T cells. Antigen presentation occurred in the context of three different class I haplotypes in vitro. A hemolysin- negative L. monocytogenes strain expressing LLO-NP was able to present in a class II-restricted manner. However, it failed to target infected cells for lysis by CD8+ T cells, indicating that hemolysin-dependent bacterial escape from the vacuole is necessary for class I presentation in vitro. Immunization of mice with a recombinant L. monocytogenes strain that stably expressed and secreted LLO-NP induced NP-specific CD8+ cytotoxic T lymphocytes. These studies have implications for the use of L. monocytogenes to deliver potentially any antigen to the class I pathway in vivo. PMID:7964496

  10. A Triad of Molecular Regions Contribute to the Formation of Two Distinct MHC Class II Conformers

    PubMed Central

    Drake, Lisa A.; Drake, James R.

    2016-01-01

    MHC class II molecules present antigen-derived peptides to CD4 T cells to drive the adaptive immune response. Previous work has established that class II αβ dimers can adopt two distinct conformations, driven by the differential pairing of transmembrane domain GxxxG dimerization motifs. These class II conformers differ in their ability to be loaded with antigen-derived peptide and to effectively engage CD4 T cells. Motif 1 (M1) paired I-Ak class II molecules are efficiently loaded with peptides derived from the processing of B cell receptor-bound antigen, have unique B cell signaling properties and high T cell stimulation activity. The 11-5.2 mAb selectively binds M1 paired I-Ak class II molecules. However, the molecular determinants of 11-5.2 binding are currently unclear. Here, we report the ability of a human class II transmembrane domain to drive both M1 and M2 class II conformer formation. Protease sensitivity analysis further strengthens the idea that there are conformational differences between the extracellular domains of M1 and M2 paired class II. Finally, MHC class II chain alignments and site directed mutagenesis reveals a triad of molecular regions that contributes to 11-5.2 mAb binding. In addition to transmembrane GxxxG motif domain pairing, 11-5.2 binding is influenced directly by α chain residue Glu-71 and indirectly by the region around the inter-chain salt bridge formed by α chain Arg-52 and β chain Glu-86. These findings provide insight into the complexity of 11-5.2 mAb recognition of the M1 paired I-Ak class II conformer and further highlight the molecular heterogeneity of peptide-MHC class II complexes that drive T cell antigen recognition. PMID:27148821

  11. Cell migration and antigen capture are antagonistic processes coupled by myosin II in dendritic cells

    PubMed Central

    Chabaud, Mélanie; Heuzé, Mélina L.; Bretou, Marine; Vargas, Pablo; Maiuri, Paolo; Solanes, Paola; Maurin, Mathieu; Terriac, Emmanuel; Le Berre, Maël; Lankar, Danielle; Piolot, Tristan; Adelstein, Robert S.; Zhang, Yingfan; Sixt, Michael; Jacobelli, Jordan; Bénichou, Olivier; Voituriez, Raphaël; Piel, Matthieu; Lennon-Duménil, Ana-Maria

    2015-01-01

    The immune response relies on the migration of leukocytes and on their ability to stop in precise anatomical locations to fulfil their task. How leukocyte migration and function are coordinated is unknown. Here we show that in immature dendritic cells, which patrol their environment by engulfing extracellular material, cell migration and antigen capture are antagonistic. This antagonism results from transient enrichment of myosin IIA at the cell front, which disrupts the back-to-front gradient of the motor protein, slowing down locomotion but promoting antigen capture. We further highlight that myosin IIA enrichment at the cell front requires the MHC class II-associated invariant chain (Ii). Thus, by controlling myosin IIA localization, Ii imposes on dendritic cells an intermittent antigen capture behaviour that might facilitate environment patrolling. We propose that the requirement for myosin II in both cell migration and specific cell functions may provide a general mechanism for their coordination in time and space. PMID:26109323

  12. Dynamics of Major Histocompatibility Complex Class II Compartments during B Cell Receptor–mediated Cell Activation

    PubMed Central

    Lankar, Danielle; Vincent-Schneider, Hélène; Briken, Volker; Yokozeki, Takeaki; Raposo, Graça; Bonnerot, Christian

    2002-01-01

    Antigen recognition by clonotypic B cell receptor (BcR) is the first step of B lymphocytes differentiation into plasmocytes. This B cell function is dependent on efficient major histocompatibility complex (MHC) class II–restricted presentation of BcR-bound antigens. In this work, we analyzed the subcellular mechanisms underlying antigen presentation after BcR engagement on B cells. In quiescent B cells, we found that MHC class II molecules mostly accumulated at the cell surface and in an intracellular pool of tubulovesicular structures, whereas H2-M molecules were mostly detected in distinct lysosomal compartments devoid of MHC class II. BcR stimulation induced the transient intracellular accumulation of MHC class II molecules in newly formed multivesicular bodies (MVBs), to which H2-M was recruited. The reversible downregulation of cathepsin S activity led to the transient accumulation of invariant chain–MHC class II complexes in MVBs. A few hours after BcR engagement, cathepsin S activity increased, the p10 invariant chain disappeared, and MHC class II–peptide complexes arrived at the plasma membrane. Thus, BcR engagement induced the transient formation of antigen-processing compartments, enabling antigen-specific B cells to become effective antigen-presenting cells. PMID:11854359

  13. Association of high CD4-positive T cell infiltration with mutations in HLA class II-regulatory genes in microsatellite-unstable colorectal cancer.

    PubMed

    Surmann, Eva-Maria; Voigt, Anita Y; Michel, Sara; Bauer, Kathrin; Reuschenbach, Miriam; Ferrone, Soldano; von Knebel Doeberitz, Magnus; Kloor, Matthias

    2015-03-01

    Besides being expressed on professional antigen-presenting cells, HLA class II antigens are expressed on various tumors of non-lymphoid origin, including a subset of colorectal cancers (CRC). Information about the regulation of HLA class II antigen expression is important for a better understanding of their role in the interactions between tumor and immune cells. Whether lack of HLA class II antigen expression in tumors reflects the selective immune destruction of HLA class II antigen-expressing tumor cells is unknown. To address this question, we tested whether lack of HLA class II antigen expression in CRC was associated with immune cell infiltration. We selected microsatellite-unstable (MSI-H) CRC, because they show pronounced tumor antigen-specific immune responses and, in a subset of tumors, lack of HLA class II antigen expression due to mutations inactivating HLA class II-regulatory genes. We examined HLA class II antigen expression, mutations in regulatory genes, and CD4-positive T cell infiltration in 69 MSI-H CRC lesions. Mutations in RFX5, CIITA, and RFXAP were found in 13 (28.9%), 3 (6.7%), and 1 (2.2%) out of 45 HLA class II antigen-negative tumors. CD4-positive tumor-infiltrating lymphocyte counts were significantly higher in HLA class II antigen-negative tumors harboring mutations in HLA class II-regulatory genes (107.4 T cells per 0.25 mm(2)) compared to tumors without mutations (55.5 T cells per 0.25 mm(2), p = 0.008). Our results suggest that the outgrowth of tumor cells lacking HLA class II antigen expression due to mutations of regulatory genes is favored in an environment of dense CD4-positive T cell infiltration.

  14. EpsinR, a target for pyrenocine B, role in endogenous MHC-II-restricted antigen presentation.

    PubMed

    Shishido, Tatsuya; Hachisuka, Masami; Ryuzaki, Kai; Miura, Yuko; Tanabe, Atsushi; Tamura, Yasuaki; Kusayanagi, Tomoe; Takeuchi, Toshifumi; Kamisuki, Shinji; Sugawara, Fumio; Sahara, Hiroeki

    2014-11-01

    While the presentation mechanism of antigenic peptides derived from exogenous proteins by MHC class II molecules is well understood, relatively little is known about the presentation mechanism of endogenous MHC class II-restricted antigens. We therefore screened a chemical library of 200 compounds derived from natural products to identify inhibitors of the presentation of endogenous MHC class II-restricted antigens. We found that pyrenocine B, a compound derived from the fungus Pyrenochaeta terrestris, inhibits presentation of endogenous MHC class II-restricted minor histocompatibility antigen IL-4 inducible gene 1 (IL4I1) by primary dendritic cells (DCs). Phage display screening and surface plasmon resonance (SPR) analysis were used to investigate the mechanism of suppressive action by pyrenocine B. EpsinR, a target molecule for pyrenocine B, mediates endosomal trafficking through binding of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). Lentiviral-mediated short hairpin (sh) RNA downregulation of EpsinR expression in DCs resulted in a decrease in the responsiveness of CD4+ T cells. Our data thus suggest that EpsinR plays a role in antigen presentation, which provides insight into the mechanism of presentation pathway of endogenous MHC class II-restricted antigen.

  15. Immunological Functions of the Membrane Proximal Region of MHC Class II Molecules

    PubMed Central

    Harton, Jonathan; Jin, Lei; Hahn, Amy; Drake, Jim

    2016-01-01

    Major histocompatibility complex (MHC) class II molecules present exogenously derived antigen peptides to CD4 T cells, driving activation of naïve T cells and supporting CD4-driven immune functions. However, MHC class II molecules are not inert protein pedestals that simply bind and present peptides. These molecules also serve as multi-functional signaling molecules delivering activation, differentiation, or death signals (or a combination of these) to B cells, macrophages, as well as MHC class II-expressing T cells and tumor cells. Although multiple proteins are known to associate with MHC class II, interaction with STING (stimulator of interferon genes) and CD79 is essential for signaling. In addition, alternative transmembrane domain pairing between class II α and β chains influences association with membrane lipid sub-domains, impacting both signaling and antigen presentation. In contrast to the membrane-distal region of the class II molecule responsible for peptide binding and T-cell receptor engagement, the membrane-proximal region (composed of the connecting peptide, transmembrane domain, and cytoplasmic tail) mediates these “non-traditional” class II functions. Here, we review the literature on the function of the membrane-proximal region of the MHC class II molecule and discuss the impact of this aspect of class II immunobiology on immune regulation and human disease. PMID:27006762

  16. Cellular misfolded proteins rescued from degradation by MHC class II molecules are possible targets for autoimmune diseases.

    PubMed

    Arase, Noriko; Arase, Hisashi

    2015-11-01

    The major function of major histocompatibility complex (MHC) class II molecules is the presentation of peptide antigens to helper T cells. However, when misfolded proteins are associated with MHC class II molecules in the endoplasmic reticulum, they are transported to the cell surface by MHC class II molecules without processing to peptides. Of note, misfolded proteins complexed with MHC class II molecules are specifically recognized by autoantibodies produced in patients with autoimmune diseases such as rheumatoid arthritis and antiphospholipid syndrome. Furthermore, autoantibody binding to misfolded proteins complexed with MHC class II molecules is associated with the susceptibility to autoimmune diseases conferred by each MHC class II allele. Therefore, misfolded proteins rescued from degradation by MHC class II molecules may be recognized as 'neo-self' antigens by the immune system and be involved in the pathogenicity of autoimmune diseases.

  17. Achieving stability through editing and chaperoning: regulation of MHC class II peptide binding and expression.

    PubMed

    Busch, Robert; Rinderknecht, Cornelia H; Roh, Sujin; Lee, Andrew W; Harding, James J; Burster, Timo; Hornell, Tara M C; Mellins, Elizabeth D

    2005-10-01

    In antigen-presenting cells (APCs), loading of major histocompatibility complex class II (MHC II) molecules with peptides is regulated by invariant chain (Ii), which blocks MHC II antigen-binding sites in pre-endosomal compartments. Several molecules then act upon MHC II molecules in endosomes to facilitate peptide loading: Ii-degrading proteases, the peptide exchange factor, human leukocyte antigen-DM (HLA-DM), and its modulator, HLA-DO (DO). Here, we review our findings arguing that DM stabilizes a globally altered conformation of the antigen-binding groove by binding to a lateral surface of the MHC II molecule. Our data imply changes in the interactions between specificity pockets and peptide side chains, complementing data from others that suggest DM affects hydrogen bonds. Selective weakening of peptide/MHC interactions allows DM to alter the peptide repertoire. We also review our studies in cells that highlight the ability of several factors to modulate surface expression of MHC II molecules via post-Golgi mechanisms; these factors include MHC class II-associated Ii peptides (CLIP), DM, and microbial products that modulate MHC II traffic from endosomes to the plasma membrane. In this context, we discuss possible mechanisms by which the association of some MHC II alleles with autoimmune diseases may be linked to their low CLIP affinity.

  18. Ancient haplotypes of the HLA Class II region.

    PubMed

    Raymond, Christopher K; Kas, Arnold; Paddock, Marcia; Qiu, Ruolan; Zhou, Yang; Subramanian, Sandhya; Chang, Jean; Palmieri, Anthony; Haugen, Eric; Kaul, Rajinder; Olson, Maynard V

    2005-09-01

    Allelic variation in codons that specify amino acids that line the peptide-binding pockets of HLA's Class II antigen-presenting proteins is superimposed on strikingly few deeply diverged haplotypes. These haplotypes appear to have been evolving almost independently for tens of millions of years. By complete resequencing of 20 haplotypes across the approximately 100-kbp region that spans the HLA-DQA1, -DQB1, and -DRB1 genes, we provide a detailed view of the way in which the genome structure at this locus has been shaped by the interplay of selection, gene-gene interaction, and recombination.

  19. Conservation of MHC class II DOA sequences among carnivores.

    PubMed

    Soll, S J; Stewart, B S; Lehman, N

    2005-03-01

    We obtained the nucleotide sequence for most of the major histocompatibility complex (MHC) class II DOA locus for Weddell, leopard, northern elephant, and southern elephant seals and from the coyote and compared them to all known DOA data available to date. We found generally low levels of interspecific polymorphisms, providing further support for stabilizing selection acting on the DOA locus. This suggests that DO gene products play a substantial functional role in the regulation of antigen presentation. A seven-amino-acid motif of VWRLPEF was found to be conserved across all DOA sequences and may be a DO-specific recognition element.

  20. Differential Transmembrane Domain GXXXG Motif Pairing Impacts Major Histocompatibility Complex (MHC) Class II Structure*

    PubMed Central

    Dixon, Ann M.; Drake, Lisa; Hughes, Kelly T.; Sargent, Elizabeth; Hunt, Danielle; Harton, Jonathan A.; Drake, James R.

    2014-01-01

    Major histocompatibility complex (MHC) class II molecules exhibit conformational heterogeneity, which influences their ability to stimulate CD4 T cells and drive immune responses. Previous studies suggest a role for the transmembrane domain of the class II αβ heterodimer in determining molecular structure and function. Our previous studies identified an MHC class II conformer that is marked by the Ia.2 epitope. These Ia.2+ class II conformers are lipid raft-associated and able to drive both tyrosine kinase signaling and efficient antigen presentation to CD4 T cells. Here, we establish that the Ia.2+ I-Ak conformer is formed early in the class II biosynthetic pathway and that differential pairing of highly conserved transmembrane domain GXXXG dimerization motifs is responsible for formation of Ia.2+ versus Ia.2− I-Ak class II conformers and controlling lipid raft partitioning. These findings provide a molecular explanation for the formation of two distinct MHC class II conformers that differ in their inherent ability to signal and drive robust T cell activation, providing new insight into the role of MHC class II in regulating antigen-presenting cell-T cell interactions critical to the initiation and control of multiple aspects of the immune response. PMID:24619409

  1. Trafficking of major histocompatibility complex class II molecules through intracellular compartments containing HLA-DM.

    PubMed

    Robbins, N F; Hammond, C; Denzin, L K; Pan, M; Cresswell, P

    1996-01-01

    The endosomal site(s) where MHC class II molecules become competent to bind antigenic peptide has not been completely characterized. We identified endocytic compartments through which newly synthesized MHC class II molecules move prior to their expression on the plasma membrane. The compartments co-sediment with lysosomes in the most dense regions of Percoll gradients. The appearance of proteolytic fragments of the invariant chain (I chain), namely leupeptin-induced proteins (LIPs) and class-II-associated invariant chain peptides (CLIP), in this region of the gradient suggests that the release of MHC class II molecules from I chain association occurs within these vesicles. The formation of SDS-stable alpha beta dimers indicated that MHC class II molecules contained within these compartments are receptive to peptide binding. A majority of the HLA-DM protein was found in the same region of the Percoll gradient, consistent with its established function in MHC class-II-restricted antigen presentation. Immunoelectron micrographs of dense-sedimenting compartments indicated that I chain, MHC class II, and DM molecules are contained within both multivesicular and multilamellar vesicles. The final stages of I chain dissociation from MHC class II molecules and DM-mediated peptide loading probably occur in these compartments.

  2. PD-L1 and HLA Class I Antigen Expression and Clinical Course of the Disease in Intrahepatic Cholangiocarcinoma.

    PubMed

    Sabbatino, Francesco; Villani, Vincenzo; Yearley, Jennifer H; Deshpande, Vikram; Cai, Lei; Konstantinidis, Ioannis T; Moon, Christina; Nota, Sjoerd; Wang, Yangyang; Al-Sukaini, Ahmad; Zhu, Andrew X; Goyal, Lipika; Ting, David T; Bardeesy, Nabeel; Hong, Theodore S; Fernandez-del Castillo, Carlos; Tanabe, Kenneth K; Lillemoe, Keith D; Ferrone, Soldano; Ferrone, Cristina R

    2016-01-15

    More effective therapy is needed for intrahepatic cholangiocarcinoma (ICC). The encouraging clinical results obtained with checkpoint molecule-specific monoclonal antibodies (mAb) have prompted us to investigate whether this type of immunotherapy may be applicable to ICC. The aims of this study were to determine whether (i) patients mount a T-cell immune response to their ICC, (ii) checkpoint molecules are expressed on both T cells and tumor cells, and (iii) tumor cells are susceptible to recognition by cognate T cells. Twenty-seven ICC tumors were analyzed for (i) lymphocyte infiltrate, (ii) HLA class I and HLA class II expression, and (iii) PD-1 and PD-L1 expression by T cells and ICC cells, respectively. The results of this analysis were correlated with the clinicopathologic characteristics of the patients investigated. Lymphocyte infiltrates were identified in all tumors. PD-L1 expression and HLA class I antigen expression by ICC cells was observed in 8 and 11, respectively, of the 27 tumors analyzed. HLA class I antigen expression correlated with CD8(+) T-cell infiltrate. Furthermore, positive HLA class I antigen expression in combination with negative/rare PD-L1 expression was associated with favorable clinical course of the disease. ICC patients are likely to mount a T-cell immune response against their own tumors. Defects in HLA class I antigen expression in combination with PD-L1 expression by ICC cells provide them with an immune escape mechanism. This mechanism justifies the implementation of immunotherapy with checkpoint molecule-specific mAbs in patients bearing ICC tumors without defects in HLA class I antigen expression. ©2015 American Association for Cancer Research.

  3. Rheumatoid Rescue of Misfolded Cellular Proteins by MHC Class II Molecules: A New Hypothesis for Autoimmune Diseases.

    PubMed

    Arase, Hisashi

    2016-01-01

    Misfolded proteins localized in the endoplasmic reticulum are degraded promptly and thus are not transported outside cells. However, misfolded proteins in the endoplasmic reticulum are rescued from protein degradation upon association with major histocompatibility complex (MHC) class II molecules and are transported to the cell surface by MHC class II molecules without being processed to peptides. Studies on the misfolded proteins rescued by MHC class II molecules have revealed that misfolded proteins associated with MHC class II molecules are specific targets for autoantibodies produced in autoimmune diseases. Furthermore, a strong correlation has been observed between autoantibody binding to misfolded proteins associated with MHC class II molecules and the autoimmune disease susceptibility conferred by each MHC class II allele. These new insights into MHC class II molecules suggest that misfolded proteins rescued from protein degradation by MHC class II molecules are recognized as "neo-self" antigens by immune system and are involved in autoimmune diseases as autoantibody targets.

  4. Class II malocclusion occlusal severity description

    PubMed Central

    JANSON, Guilherme; SATHLER, Renata; FERNANDES, Thais Maria Freire; ZANDA, Marcelo; PINZAN, Arnaldo

    2010-01-01

    Objectives It is well known that the efficacy and the efficiency of a Class II malocclusion treatment are aspects closely related to the severity of the dental anteroposterior discrepancy. Even though, sample selection based on cephalometric variables without considering the severity of the occlusal anteroposterior discrepancy is still common in current papers. In some of them, when occlusal parameters are chosen, the severity is often neglected. The purpose of this study is to verify the importance given to the classification of Class II malocclusion, based on the criteria used for sample selection in a great number of papers published in the orthodontic journal with the highest impact factor. Material and Methods A search was performed in PubMed database for full-text research papers referencing Class II malocclusion in the history of the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO). Results A total of 359 papers were retrieved, among which only 72 (20.06%) papers described the occlusal severity of the Class II malocclusion sample. In the other 287 (79.94%) papers that did not specify the anteroposterior discrepancy severity, description was considered to be crucial in 159 (55.40%) of them. Conclusions Omission in describing the occlusal severity demands a cautious interpretation of 44.29% of the papers retrieved in this study. PMID:20835576

  5. DNA and Protein Studies of HLA Class II Molecules: Their Relationship to T Cell Recognition,

    DTIC Science & Technology

    1985-01-01

    ramifications. SEQUENCING OF CLASS II 0 GENES Although very few sequences are available for HLA class II genes (41-x), it seems that there are at least...108. Cairns, S., Dahl, C., Curtsinger, 3., Freeman, S., Nelson, P., Alter, B.3. & Bach, F.H. Sequence analysis of HLA -DR 8 chains: comparison among...chain as predicted from the nucleotide sequence : Similarities with imiunoglobulins and HLA -A, -B, and -C antigens. Proc. Nati. Acad. Sei. (USA) 79:3687

  6. 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.

    PubMed Central

    Oyaizu, N; Chirmule, N; Pahwa, S

    1992-01-01

    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-specific human Th clones. Pretreatment of the Th clones with Leu3a resulted in a dose-dependent suppression of antigen-induced proliferative responses, inositol phosphate accumulation, increase in free cytoplasmic calcium ions ([Ca2+]i), IL-2 mRNA accumulation, IL-2 secretion, and membrane IL-2R expression. IL-2R mRNA accumulation, however, was unaffected even at highest Leu3a concentrations. Leu3a treatment did not affect bypass activation of T cells with PMA plus ionomycin or activation via CD2 molecule. The MAb OKT4, which binds another domain of CD4, was not inhibitory. These results suggest that after T cell antigen receptor-CD3 activation, IL-2 gene induction, IL-2 secretion, and membrane IL-2R expression are absolutely dependent upon participation of CD4 molecules, phosphatidylinositol (PI) hydrolysis, and increase in [Ca2+]i. The requirement for IL-2R gene induction, however, occurs independently of CD4 molecule participation and PI hydrolysis. Images PMID:1534818

  7. Transport of misfolded endoplasmic reticulum proteins to the cell surface by MHC class II molecules

    PubMed Central

    Jiang, Yan; Arase, Noriko

    2013-01-01

    Nascent MHC class II molecules are associated with the invariant chain and are transported to the endolysosomal pathway, where MHC class II molecules acquire peptide antigens. On the other hand, misfolded endoplasmic reticulum (ER) proteins are generally degraded in the cells and are neither expressed on the cell surface nor secreted. Here, we found that MHC class II molecules associate with some misfolded ER proteins via the peptide-binding groove in competition with invariant chain. The misfolded proteins associated with MHC class II molecules are transported intact to the cell surface without processing to peptides. Furthermore, these complexes efficiently stimulate antigen-specific B cells. These findings reveal that MHC class II molecules function as a chaperone for the cell surface expression of misfolded ER proteins. In addition, we suggest that MHC class II molecules present not only peptides but also intact host-cell-derived proteins on the cell surface. These findings provide new insights into the function of MHC class II molecules. PMID:23334921

  8. Contemporary treatment of class II dens invaginatus.

    PubMed

    Sathorn, C; Parashos, P

    2007-04-01

    To present the nonsurgical management of a tooth with class II dens invaginatus with an open apex utilizing contemporary techniques. Root canal treatment of teeth with complex root canal anatomy such as dens invaginatus can be problematic because infected pulpal tissues may remain in inaccessible areas of the canal system. The cleaning and debridement of such root canal systems are therefore challenging and may sometimes be considered impossible. An immature apical root-end development is another challenge in root canal treatment especially in controlling the apical extent of the filling material and achieving an apical seal. When difficulties in cleaning and filling combine, management options may include surgical intervention or extraction. This article reports the nonsurgical endodontic treatment of a case of an open apex and dens invaginatus utilizing the operating microscope, endodontic ultrasonic instruments and mineral trioxide aggregate. Teeth with class II dens evaginatus and an open apex may be managed successfully with contemporary nonsurgical materials and techniques.

  9. Mechanistic understanding and significance of small peptides interaction with MHC class II molecules for therapeutic applications.

    PubMed

    Afridi, Saifullah; Hoessli, Daniel C; Hameed, Muhammad Waqar

    2016-07-01

    Major histocompatibility complex (MHC) class II molecules are expressed by antigen-presenting cells and stimulate CD4(+) T cells, which initiate humoral immune responses. Over the past decade, interest has developed to therapeutically impact the peptides to be exposed to CD4(+) T cells. Structurally diverse small molecules have been discovered that act on the endogenous peptide exchanger HLA-DM by different mechanisms. Exogenously delivered peptides are highly susceptible to proteolytic cleavage in vivo; however, it is only when successfully incorporated into stable MHC II-peptide complexes that these peptides can induce an immune response. Many of the small molecules so far discovered have highlighted the molecular interactions mediating the formation of MHC II-peptide complexes. As potential drugs, these small molecules open new therapeutic approaches to modulate MHC II antigen presentation pathways and influence the quality and specificity of immune responses. This review briefly introduces how CD4(+) T cells recognize antigen when displayed by MHC class II molecules, as well as MHC class II-peptide-loading pathways, structural basis of peptide binding and stabilization of the peptide-MHC complexes. We discuss the concept of MHC-loading enhancers, how they could modulate immune responses and how these molecules have been identified. Finally, we suggest mechanisms whereby MHC-loading enhancers could act upon MHC class II molecules.

  10. Class II transactivator-induced MHC class II expression in pancreatic cancer cells leads to tumor rejection and a specific antitumor memory response.

    PubMed

    Ekkirala, Chaitanya Ramesh; Cappello, Paola; Accolla, Roberto S; Giovarelli, Mirella; Romero, Irene; Garrido, Cristina; Garcia-Lora, Angel Miguel; Novelli, Francesco

    2014-10-01

    The loss of major histocompatibility complex (MHC) classes I and II is a well-known mechanism by which cancer cells are able to escape from immune recognition. In this study, we analyzed the expression of antigen processing and presenting molecules in 2 cell lines derived from mouse models of pancreatic ductal adenocarcinoma (PDA) and the effects of the re-expression of MHC class II on PDA rejection. The PDA cell lines were analyzed for the expression of MHC class I, II, and antigen-processing molecules by flow cytometry or polymerase chain reaction. We generated stable PDA-MHC class II transactivator (CIITA) cells and injected them into syngeneic mice. The CD4 and CD8 T-cell role was analyzed in vitro and in vivo. Murine PDA cell lines were negative for MHC and antigen-processing molecules, but their expression was restored by exogenous interferon-γ. CIITA-tumor cells were rejected in 80% to 100% of injected mice, which also developed long-lasting immune memory. In vitro assays and immunohistochemical analyses revealed the recruitment of T effector cells and CD8 T cells into the tumor area. Overall, these data confirm that immunotherapy is a feasible therapeutic approach to recognize and target an aggressive cancer such as PDA.

  11. Association of human leukocyte antigen class I antigens in Iranian patients with pemphigus vulgaris.

    PubMed

    Mortazavi, Hossein; Amirzargar, Ali Akbar; Esmaili, Nafiseh; Toofan, Hesam; Ehsani, Amir Hooshang; Hosseini, Seyed Hamed; Rezaei, Nima

    2013-04-01

    There are a limited number of reports indicating the role of human leukocyte antigen (HLA) class I alleles in pemphigus vulgaris. This study was designed to highlight the association of HLA class I alleles with pemphigus vulgaris in Iran. Fifty patients with pemphigus vulgaris, diagnosed based on clinical, histological and direct immunofluorescence findings were enrolled into this study. The control group consisted of 50 healthy, age- and sex-matched individuals. HLA typing of class I (A, B and C alleles) was carried out using polymerase chain reaction based on the sequence-specific primer method. This study showed the higher frequency of HLA-B*44:02 (P = 0.007), -C*04:01 (P < 0.001), -C*15:02 (P < 0.001) and -C*16:01 (P = 0.027) in the patient group, compared to the controls, while the frequency of HLA-C*06:02 (P < 0.001) and -C*18:01 (P = 0.008) in the patients with pemphigus vulgaris was significantly lower than the controls. Regarding the linkage disequilibrium between HLA class I alleles, the HLA-A*03:01, -B*51:01, -C*16:02 haplotype (4% vs 0%, P = 0.04) is suggested to be a predisposing factor, whereas HLA-A*26:01, -B*38, -C*12:03 haplotype (0% vs 6%, P = 0.01) is suggested to be a protective factor. In conclusion, it is suggested that HLA-B*44:02, -C*04:01, -C*15:02 alleles and HLA-A*03:01, -B*51:01, -C*16:02 haplotype are susceptibility factors for development of pemphigus vulgaris in the Iranian population, while HLA-C*06:02, -C*18:01 alleles and HLA-A*26:01, -B*38, -C*12:03 haplotype may be considered as protective alleles.

  12. Preferred SLA class I/class II haplotype combinations in German Landrace pigs.

    PubMed

    Gimsa, Ulrike; Ho, Chak-Sum; Hammer, Sabine E

    2017-01-01

    Major histocompatibility complex (MHC) molecules are responsible for the antigen presentation to T lymphocytes. High recombination rates in the MHC genes, as observed in humans, are believed to serve the evolutionary goal to achieve a high genetic diversity, allowing for a broad and efficient immune response. In a cohort of 155 pedigreed German Landrace pigs (65 founders and 90 piglets), we found that MHC genes occur in particular class I and class II haplotype combinations. This phenomenon has not been described before, probably because most of the earlier MHC studies in pigs were not pedigree-based. After comparing our data with published genotypes of different European pig breeds and Asian pigs, we hypothesise that the combination of particular but different haplotypes in different geographical regions may have developed under the evolutionary pressure of regionally endemic pathogens. This proposed mechanism ensures an efficient immune response despite low recombination rates.

  13. MHC class I and class II genes in Tunisian patients with reactive and undifferentiated arthritis.

    PubMed

    Siala, M; Mahfoudh, N; Fourati, H; Gdoura, R; Younes, M; Kammoun, A; Chour, I; Meddeb, N; Gaddour, L; Hakim, F; Baklouti, S; Bargaoui, N; Sellami, S; Hammami, A; Makni, H

    2009-01-01

    To study HLA class I and class II association in Tunisian patients with reactive (ReA) and undifferentiated arthritis (UA). The study included 17 patients with ReA defined according to the European Spondylarthropathy Study Group criteria for spondylarthropathy (SpA), 11 patients classified as having undifferentiated arthritis and 100 unrelated healthy controls. HLA class I antigens were typed serologically and HLA class II alleles were genotyped molecularly by the polymerase chain reaction with sequence-specific primers technique. There was a major difference between HLA alleles in ReA and UA patients when compared separately with controls. Increased frequencies of HLA-B27 (p=7.76 10-12, OR=59.30), HLA-B51 (p=0.015, OR=4.91) and HLA-DRB1*04 (p=0.033, OR=2.90) alleles were found in patients with ReA but not in patients with UA. HLA-B27 was not expressed totally in our cohort of UA patients. A significant increase of HLA-B15 (p=0.002, OR=18.40) and a moderate increase of HLA-B7 (p=0.043, OR=5.15) was found in patients with UA, but not in patients with ReA. In the B27 negative patients, HLA-DRB1*04 association with ReA was found independently of B27. Our data confirmed a significant association of HLA-B27 with ReA in the Tunisian population. Our results also suggested that some of the additional HLA antigens were associated with ReA including HLA-B51 and HLA-DRB1*04 alleles. UA seemed to have a genetic background different from ReA in Tunisian patients.

  14. Class II HLA interactions modulate genetic risk for multiple sclerosis

    PubMed Central

    Dilthey, Alexander T; Xifara, Dionysia K; Ban, Maria; Shah, Tejas S; Patsopoulos, Nikolaos A; Alfredsson, Lars; Anderson, Carl A; Attfield, Katherine E; Baranzini, Sergio E; Barrett, Jeffrey; Binder, Thomas M C; Booth, David; Buck, Dorothea; Celius, Elisabeth G; Cotsapas, Chris; D’Alfonso, Sandra; Dendrou, Calliope A; Donnelly, Peter; Dubois, Bénédicte; Fontaine, Bertrand; Fugger, Lars; Goris, An; Gourraud, Pierre-Antoine; Graetz, Christiane; Hemmer, Bernhard; Hillert, Jan; Kockum, Ingrid; Leslie, Stephen; Lill, Christina M; Martinelli-Boneschi, Filippo; Oksenberg, Jorge R; Olsson, Tomas; Oturai, Annette; Saarela, Janna; Søndergaard, Helle Bach; Spurkland, Anne; Taylor, Bruce; Winkelmann, Juliane; Zipp, Frauke; Haines, Jonathan L; Pericak-Vance, Margaret A; Spencer, Chris C A; Stewart, Graeme; Hafler, David A; Ivinson, Adrian J; Harbo, Hanne F; Hauser, Stephen L; De Jager, Philip L; Compston, Alastair; McCauley, Jacob L; Sawcer, Stephen; McVean, Gil

    2016-01-01

    Association studies have greatly refined the understanding of how variation within the human leukocyte antigen (HLA) genes influences risk of multiple sclerosis. However, the extent to which major effects are modulated by interactions is poorly characterized. We analyzed high-density SNP data on 17,465 cases and 30,385 controls from 11 cohorts of European ancestry, in combination with imputation of classical HLA alleles, to build a high-resolution map of HLA genetic risk and assess the evidence for interactions involving classical HLA alleles. Among new and previously identified class II risk alleles (HLA-DRB1*15:01, HLA-DRB1*13:03, HLA-DRB1*03:01, HLA-DRB1*08:01 and HLA-DQB1*03:02) and class I protective alleles (HLA-A*02:01, HLA-B*44:02, HLA-B*38:01 and HLA-B*55:01), we find evidence for two interactions involving pairs of class II alleles: HLA-DQA1*01:01–HLA-DRB1*15:01 and HLA-DQB1*03:01–HLA-DQB1*03:02. We find no evidence for interactions between classical HLA alleles and non-HLA risk-associated variants and estimate a minimal effect of polygenic epistasis in modulating major risk alleles. PMID:26343388

  15. Histone Acetylation and the Regulation of Major Histocompatibility Class II Gene Expression.

    PubMed

    Suzuki, K; Luo, Y

    Major histocompatibility complex (MHC) class II molecules are essential for processing and presenting exogenous pathogen antigens to activate CD4(+) T cells. Given their central role in adaptive immune responses, MHC class II genes are tightly regulated in a tissue- and activation-specific manner. The regulation of MHC class II gene expression involves various transcription factors that interact with conserved proximal cis-acting regulatory promoter elements, as well as MHC class II transactivator that interacts with a variety of chromatin remodeling machineries. Recent studies also identified distal regulatory elements within MHC class II gene locus that provide enormous insight into the long-range coordination of MHC class II gene expression. Novel therapeutic modalities that can modify MHC class II genes at the epigenetic level are emerging and are currently in preclinical and clinical trials. This review will focus on the role of chromatin remodeling, particularly remodeling that involves histone acetylation, in the constitutive and inducible regulation of MHC class II gene expression. © 2017 Elsevier Inc. All rights reserved.

  16. Distribution of HLA class I and II genes in ankylosing spondylitis patients from Morocco.

    PubMed

    Atouf, O; Benbouazza, K; Brick, C; Saoud, B; Benseffaj, N; Amine, B; Hajjaj-Hassouni, N; Essakalli, M

    2012-12-01

    In Morocco, the patients affected by ankylosing spondylitis (AS) presents a high frequency of coxitis. Our study reports, for the first time, the polymorphism of Human Leukocyte Antigen (HLA) class I and class II molecules in the Moroccan patients. Forty-six patients diagnosed with an AS and coxitis were compared to a group of 183 healthy controls matched by age, sex and ethnic origin. The HLA typing was performed using microlymphocytotoxicity for the class I (-A, -B) and PCR-SSP for the class II (-DR, -DQ). We found a significant increase of the HLA-B27 antigen frequency (P<0.0001, RR=20.9) in AS patients (29.3%) compared to the controls (3.2%) and a significant decrease in the frequency of HLA-B12 and HLA-B18 antigens. Examination of HLA class II distribution shows a significant increase of the HLA-DRB1*11 allele frequency in patients (P<0.0001). Concerning HLA-DQB1* alleles, no significant difference between patients and controls was appreciable. The HLA-B27 antigen is involved in the predisposition to the AS with coxitis in the Moroccan population. However, the low frequency observed in our population suggests the existence of other genetic and/or environmental factors. Other HLA genes seem to confer a predisposing effect (DRB*11) or a protective effect (B12 and B18) against the disease. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Class II major histocompatibility complex tetramer staining: progress, problems, and prospects

    PubMed Central

    Vollers, Sabrina S; Stern, Lawrence J

    2008-01-01

    The use of major histocompatibility complex (MHC) tetramers in the detection and analysis of antigen-specific T cells has become more widespread since its introduction 11 years ago. Early challenges in the application of tetramer staining to CD4+ T cells centred around difficulties in the expression of various class II MHC allelic variants and the detection of low-frequency T cells in mixed populations. As many of the technical obstacles to class II MHC tetramer staining have been overcome, the focus has returned to uncertainties concerning how oligomer valency and T-cell receptor/MHC affinity affect tetramer binding. Such issues have become more important with an increase in the number of studies relying on direct ex vivo analysis of antigen-specific CD4+ T cells. In this review we discuss which problems in class II MHC tetramer staining have been solved to date, and which matters remain to be considered. PMID:18251991

  18. Early Endosomes Are Required for Major Histocompatiblity Complex Class II Transport to Peptide-loading Compartments

    PubMed Central

    Brachet, Valérie; Péhau-Arnaudet, Gérard; Desaymard, Catherine; Raposo, Graça; Amigorena, Sebastian

    1999-01-01

    Antigen presentation to CD4+ T lymphocytes requires transport of newly synthesized major histocompatibility complex (MHC) class II molecules to the endocytic pathway, where peptide loading occurs. This step is mediated by a signal located in the cytoplasmic tail of the MHC class II-associated Ii chain, which directs the MHC class II-Ii complexes from the trans-Golgi network (TGN) to endosomes. The subcellular machinery responsible for the specific targeting of MHC class II molecules to the endocytic pathway, as well as the first compartments these molecules enter after exit from the TGN, remain unclear. We have designed an original experimental approach to selectively analyze this step of MHC class II transport. Newly synthesized MHC class II molecules were caused to accumulate in the Golgi apparatus and TGN by incubating the cells at 19°C, and early endosomes were functionally inactivated by in vivo cross-linking of transferrin (Tf) receptor–containing endosomes using Tf-HRP complexes and the HRP-insoluble substrate diaminobenzidine. Inactivation of Tf-containing endosomes caused a marked delay in Ii chain degradation, peptide loading, and MHC class II transport to the cell surface. Thus, early endosomes appear to be required for delivery of MHC class II molecules to the endocytic pathway. Under cross-linking conditions, most αβIi complexes accumulated in tubules and vesicles devoid of γ-adaptin and/or mannose-6-phosphate receptor, suggesting an AP1-independent pathway for the delivery of newly synthesized MHC class II molecules from the TGN to endosomes. PMID:10473634

  19. 46 CFR 50.30-15 - Class II pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Class II pressure vessels. 50.30-15 Section 50.30-15... Fabrication Inspection § 50.30-15 Class II pressure vessels. (a) Class II pressure vessels shall be subject to... pressure vessels shall be performed during the welding of the longitudinal joint. At this time the...

  20. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... indicates that brake pipe pressure changes are properly communicated at the rear of the train; (2) For MU... 49 Transportation 4 2010-10-01 2010-10-01 false Class II brake test. 238.317 Section 238.317... Requirements for Tier I Passenger Equipment § 238.317 Class II brake test. (a) A Class II brake test shall be...

  1. Class II Resin Composites: Restorative Options.

    PubMed

    Patel, Minesh; Mehta, Shamir B; Banerji, Subir

    2015-10-01

    Tooth-coloured, resin composite restorations are amongst the most frequently prescribed forms of dental restoration to manage defects in posterior teeth. The attainment of a desirable outcome when placing posterior resin composite restorations requires the clinician to have a good understanding of the benefits (as well as the limitations) posed by this material, together with a sound knowledge of placement technique. Numerous protocols and materials have evolved to assist the dental operator with this type of demanding posterior restoration. With the use of case examples, four techniques available are reported here. CPD/Clinical Relevance: This article explores varying techniques for the restoration of Class II cavities using resin composite.

  2. Lateral cephalometric diagnosis of asymmetry in Angle Class II subdivision compared to Class I and II

    PubMed Central

    Meloti, Aparecida Fernanda; Gonçalves, Renata de Cássia; Silva, Ertty; Martins, Lídia Parsekian; dos Santos-Pinto, Ary

    2014-01-01

    Introduction Lateral cephalometric radiographs are traditionally required for orthodontic treatment, yet rarely used to assess asymmetries. Objective The objective of the present study was to use lateral cephalometric radiographs to identify existing skeletal and dentoalveolar morphological alterations in Class II subdivision and to compare them with the existing morphology in Class I and II relationship. Material and Methods Ninety initial lateral cephalometric radiographs of male and female Brazilian children aged between 12 to 15 years old were randomly and proportionally divided into three groups: Group 1 (Class I), Group 2 (Class II) and Group 3 (Class II subdivision). Analysis of lateral cephalometric radiographs included angular measurements, horizontal linear measurements and two indexes of asymmetry that were prepared for this study. Results In accordance with an Index of Dental Asymmetry (IDA), greater mandibular dental asymmetry was identified in Group 3. An Index of Mandibular Asymmetry (IMA) revealed less skeletal and dental mandibular asymmetry in Group 2, greater skeletal mandibular asymmetry in Group 1, and greater mandibular dental asymmetry in Group 3. Conclusion Both IDA and IMA revealed greater mandibular dental asymmetry for Group 3 in comparison to Groups 1 and 2. These results are in accordance with those found by other diagnostic methods, showing that lateral cephalometric radiography is an acceptable method to identify existing skeletal and dentoalveolar morphological alterations in malocclusions. PMID:25279525

  3. 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

    PubMed Central

    Accolla, Roberto S.; Lombardo, Letizia; Abdallah, Rawan; Raval, Goutham; Forlani, Greta; Tosi, Giovanna

    2014-01-01

    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 (TH) cell 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 and 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 by 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 and myeloid-derived-suppressor cells. 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. PMID:24600588

  4. The role of "indirect" recognition in initiating rejection of skin grafts from major histocompatibility complex class II-deficient mice.

    PubMed Central

    Auchincloss, H; Lee, R; Shea, S; Markowitz, J S; Grusby, M J; Glimcher, L H

    1993-01-01

    In vitro studies have revealed several pathways by which T cells can respond to alloantigens, including CD4+ direct responses to allogeneic class II antigens, CD8+ direct responses to allogeneic class I antigens, and CD4+ "indirect" responses to peptides of alloantigens presented in association with responder class II molecules. In vivo studies of skin graft rejection, however, have so far provided clear evidence for the contribution of only the two direct pathways and not for indirect recognition. We have used major histocompatibility complex class II-deficient mice as donors to test the role of indirect recognition in rejection of skin grafts. Class II-deficient skin was always rejected without delay by normal recipients. Removal of recipient CD8+ cells (to leave the animals dependent on CD4+ function) or depletion of recipient CD4+ cells revealed that CD4+ cells were usually involved and sometimes absolutely required in this rapid rejection. Since the donor grafts lacked class II antigens, the CD4+ cells must have recognized donor antigens presented in association with recipient class II molecules. These results therefore indicate that indirect recognition can initiate rapid skin graft rejection. PMID:8475083

  5. MHC class II tetramers made from isolated recombinant α and β chains refolded with affinity-tagged peptides.

    PubMed

    Braendstrup, Peter; Justesen, Sune; Osterbye, Thomas; Nielsen, Lise Lotte Bruun; Mallone, Roberto; Vindeløv, Lars; Stryhn, Anette; Buus, Søren

    2013-01-01

    Targeting CD4+ T cells through their unique antigen-specific, MHC class II-restricted T cell receptor makes MHC class II tetramers an attractive strategy to identify, validate and manipulate these cells at the single cell level. Currently, generating class II tetramers is a specialized undertaking effectively limiting their use and emphasizing the need for improved methods of production. Using class II chains expressed individually in E. coli as versatile recombinant reagents, we have previously generated peptide-MHC class II monomers, but failed to generate functional class II tetramers. Adding a monomer purification principle based upon affinity-tagged peptides, we here provide a robust method to produce class II tetramers and demonstrate staining of antigen-specific CD4+ T cells. We also provide evidence that both MHC class II and T cell receptor molecules largely accept affinity-tagged peptides. As a general approach to class II tetramer generation, this method should support rational CD4+ T cell epitope discovery as well as enable specific monitoring and manipulation of CD4+ T cell responses.

  6. Tumor-specific CD4+ T cells eradicate myeloma cells genetically deficient in MHC class II display

    PubMed Central

    Tveita, Anders; Fauskanger, Marte; Bogen, Bjarne; Haabeth, Ole Audun Werner

    2016-01-01

    CD4+ T cells have been shown to reject tumor cells with no detectable expression of major histocompatibility complex class II (MHC II). However, under certain circumstances, induction of ectopic MHC II expression on tumor cells has been reported. To confirm that CD4+ T cell-mediated anti-tumor immunity can be successful in the complete absence of antigen display on the tumor cells themselves, we eliminated MHC II on tumor cells using CRISPR/Cas9. Our results demonstrate that ablation of the relevant MHC II (I-Ed) in multiple myeloma cells (MOPC315) does not hinder rejection by tumor-specific CD4+ T cells. These findings provide conclusive evidence that CD4+ T cells specific for tumor antigens can eliminate malignant cells in the absence of endogenous MHC class II expression on the tumor cells. This occurs through antigen uptake and indirect presentation on tumor-infiltrating macrophages. PMID:27626487

  7. β2-Glycoprotein I/HLA class II complexes are novel autoantigens in antiphospholipid syndrome

    PubMed Central

    Tanimura, Kenji; Jin, Hui; Suenaga, Tadahiro; Morikami, Satoko; Arase, Noriko; Kishida, Kazuki; Hirayasu, Kouyuki; Kohyama, Masako; Ebina, Yasuhiko; Yasuda, Shinsuke; Horita, Tetsuya; Takasugi, Kiyoshi; Ohmura, Koichiro; Yamamoto, Ken; Katayama, Ichiro; Sasazuki, Takehiko; Lanier, Lewis L.; Atsumi, Tatsuya; Yamada, Hideto

    2015-01-01

    Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy complications. β2-glycoprotein I (β2GPI) complexed with phospholipid is recognized as a major target for autoantibodies in APS; however, less than half the patients with clinical manifestations of APS possess autoantibodies against the complexes. Therefore, the range of autoantigens involved in APS remains unclear. Recently, we found that human leukocyte antigen (HLA) class II molecules transport misfolded cellular proteins to the cell surface via association with their peptide-binding grooves. Furthermore, immunoglobulin G heavy chain/HLA class II complexes were specific targets for autoantibodies in rheumatoid arthritis. Here, we demonstrate that intact β2GPI, not peptide, forms a complex with HLA class II molecules. Strikingly, 100 (83.3%) of the 120 APS patients analyzed, including those whose antiphospholipid antibody titers were within normal range, possessed autoantibodies that recognize β2GPI/HLA class II complexes in the absence of phospholipids. In situ association between β2GPI and HLA class II was observed in placental tissues of APS patients but not in healthy controls. Furthermore, autoantibodies against β2GPI/HLA class II complexes mediated complement-dependent cytotoxicity against cells expressing the complexes. These data suggest that β2GPI/HLA class II complexes are a target in APS that might be involved in the pathogenesis. PMID:25733579

  8. β2-Glycoprotein I/HLA class II complexes are novel autoantigens in antiphospholipid syndrome.

    PubMed

    Tanimura, Kenji; Jin, Hui; Suenaga, Tadahiro; Morikami, Satoko; Arase, Noriko; Kishida, Kazuki; Hirayasu, Kouyuki; Kohyama, Masako; Ebina, Yasuhiko; Yasuda, Shinsuke; Horita, Tetsuya; Takasugi, Kiyoshi; Ohmura, Koichiro; Yamamoto, Ken; Katayama, Ichiro; Sasazuki, Takehiko; Lanier, Lewis L; Atsumi, Tatsuya; Yamada, Hideto; Arase, Hisashi

    2015-04-30

    Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy complications. β2-glycoprotein I (β2GPI) complexed with phospholipid is recognized as a major target for autoantibodies in APS; however, less than half the patients with clinical manifestations of APS possess autoantibodies against the complexes. Therefore, the range of autoantigens involved in APS remains unclear. Recently, we found that human leukocyte antigen (HLA) class II molecules transport misfolded cellular proteins to the cell surface via association with their peptide-binding grooves. Furthermore, immunoglobulin G heavy chain/HLA class II complexes were specific targets for autoantibodies in rheumatoid arthritis. Here, we demonstrate that intact β2GPI, not peptide, forms a complex with HLA class II molecules. Strikingly, 100 (83.3%) of the 120 APS patients analyzed, including those whose antiphospholipid antibody titers were within normal range, possessed autoantibodies that recognize β2GPI/HLA class II complexes in the absence of phospholipids. In situ association between β2GPI and HLA class II was observed in placental tissues of APS patients but not in healthy controls. Furthermore, autoantibodies against β2GPI/HLA class II complexes mediated complement-dependent cytotoxicity against cells expressing the complexes. These data suggest that β2GPI/HLA class II complexes are a target in APS that might be involved in the pathogenesis.

  9. Downregulation of class II transactivator (CIITA) expression by synthetic cannabinoid CP55,940.

    PubMed

    Gongora, Celine; Hose, Stacey; O'Brien, Terrence P; Sinha, Debasish

    2004-01-30

    Cannabinoid receptors are known to be expressed in microglia; however, their involvement in specific aspects of microglial immune function has not been demonstrated. Many effects of cannabinoids are mediated by two G-protein coupled receptors, designated CB1 and CB2. We have shown that the CB1 receptor is expressed in microglia that also express MHC class II antigen (J. Neuroimmunol. 82 (1998) 13-21). In our present study, we have analyzed the effect of cannabinoid agonist CP55,940 on MHC class II expression on the surface of IFN-gamma induced microglial cells by flow cytometry. CP55,940 blocked the class II MHC expression induced by IFN-gamma. It has been shown that the regulation of class II MHC genes occurs primarily at the transcriptional level, and a non-DNA binding protein, class II transactivator (CIITA), has been shown to be the master activator for class II transcription. We find that mRNA levels of CIITA are increased in IFN-gamma induced EOC 20 microglial cells and that this increase is almost entirely eliminated by the cannabinoid agonist CP55,940. These data suggests that cannabinoids affect MHC class II expression through actions on CIITA at the transcriptional level.

  10. A structural transition in class II major histocompatibility complex proteins at mildly acidic pH

    PubMed Central

    1996-01-01

    Peptide binding by class II major histocompatibility complex proteins is generally enhanced at low pH in the range of hydrogen ion concentrations found in the endosomal compartments of antigen- presenting cells. We and others have proposed that class II molecules undergo a reversible conformational change at low pH that is associated with enhanced peptide loading. However, no one has previously provided direct evidence for a structural change in class II proteins in the mildly acidic pH conditions in which enhanced peptide binding is observed. In this study, susceptibility to denaturation induced by sodium dodecyl sulfate (SDS) detergent or heat was used to probe the conformation of class II at different hydrogen ion concentrations. Class II molecules became sensitive to denaturation at pH 5.5-6.5 depending on the allele and experimental conditions. The observed structural transition was fully reversible if acidic pH was neutralized before exposure to SDS or heat. Experiments with the environment- sensitive fluorescent probe ANS (8-anilino-1-naphthalene-sulfonic acid) provided further evidence for a reversible structural transition at mildly acidic pH associated with an increase in exposed hydrophobicity in class II molecules. IAd conformation was found to change at a higher pH than IEd, IEk, or IAk, which correlates with the different pH optimal for peptide binding by these molecules. We conclude that pH regulates peptide binding by influencing the structure of class II molecules. PMID:8551215

  11. Role of MHC class II expressing CD4+ T cells in proteolipid protein(91-110)-induced EAE in HLA-DR3 transgenic mice.

    PubMed

    Mangalam, Ashutosh; Rodriguez, Moses; David, Chella

    2006-12-01

    MHC class II molecules play a central role in the control of adaptive immune responses through selection of the CD4(+) T cell repertoire in the thymus and antigen presentation in the periphery. Inherited susceptibility to autoimmune disorders such as multiple sclerosis, rheumatoid arthritis and IDDM are associated with particular MHC class II alleles. Advent of HLA transgenic mice has helped us in deciphering the role of particular HLA DR and DQ class II molecules in human autoimmune diseases. In mice, the expression of class II is restricted to professional antigen-presenting cells (APC). However, in humans, class II is also expressed on T cells, unlike murine T cells. We have developed new humanized HLA class II transgenic mice expressing class II molecules not only on APC but also on a subset of CD4(+) T cells. The expression of class II on CD4(+) T cells is inducible, and class II(+) CD4(+) T cells can present antigen in the absence of APC. Further, using EAE, a well-established animal model of MS, we tested the functional significance of these class II(+) CD4(+) T cells. DR3.AEo transgenic mice were susceptible to proteolipid protein(91-110)-induced EAE and showed CNS pathology accompanied by widespread inflammation and demyelination seen in human MS patients, suggesting a role for class II(+) CD4(+) T cells in the pathogenesis.

  12. Antigen Presentation by Dendritic Cells after Immunization with DNA Encoding a Major Histocompatibility Complex Class II–restricted Viral Epitope

    PubMed Central

    Casares, Sofia; Inaba, Kayo; Brumeanu, Teodor-Doru; Steinman, Ralph M.; Bona, Constantin A.

    1997-01-01

    Intramuscular and intracutaneous immunization with naked DNA can vaccinate animals to the encoded proteins, but the underlying mechanisms of antigen presentation are unclear. We used DNA that encodes an A/PR/8/34 influenza peptide for CD4 T cells and that elicits protective antiviral immunity. DNA-transfected, cultured muscle cells released the influenza polypeptide, which then could be presented on the major histocompatibility complex class II molecules of dendritic cells. When DNA was injected into muscles or skin, and antigen-presenting cells were isolated from either the draining lymph nodes or the skin, dendritic, but not B, cells presented antigen to T cells and carried plasmid DNA. We suggest that the uptake of DNA and/or the protein expressed by dendritic cells triggers immune responses to DNA vaccines. PMID:9348305

  13. Fluorogenic Probes for Monitoring Peptide Binding to Class II MHC Proteins in Living Cells

    SciTech Connect

    Venkatraman,P.; Nguyen, T.; Sainlos, M.; Bilsel, o.; Chitta, S.; Imperiali, B.; Stern, L.

    2007-01-01

    A crucial step in the immune response is the binding of antigenic peptides to major histocompatibility complex (MHC) proteins. Class II MHC proteins present their bound peptides to CD4+ T cells, thereby helping to activate both the humoral and the cellular arms of the adaptive immune response. Peptide loading onto class II MHC proteins is regulated temporally, spatially and developmentally in antigen-presenting cells1. To help visualize these processes, we have developed a series of novel fluorogenic probes that incorporate the environment-sensitive amino acid analogs 6-N,N-dimethylamino-2-3-naphthalimidoalanine and 4-N,N-dimethylaminophthalimidoalanine. Upon binding to class II MHC proteins these fluorophores show large changes in emission spectra, quantum yield and fluorescence lifetime. Peptides incorporating these fluorophores bind specifically to class II MHC proteins on antigen-presenting cells and can be used to follow peptide binding in vivo. Using these probes we have tracked a developmentally regulated cell-surface peptide-binding activity in primary human monocyte-derived dendritic cells.

  14. Characterization of major histocompatibility complex class I and class II genes from the Tasmanian devil (Sarcophilus harrisii).

    PubMed

    Siddle, Hannah V; Sanderson, Claire; Belov, Katherine

    2007-09-01

    The Tasmanian devil (Sarcophilus harrisii) is currently threatened by an emerging wildlife disease, devil facial tumour disease. The disease is decreasing devil numbers dramatically and may lead to the extinction of the species. At present, nothing is known about the immune genes or basic immunology of the devil. In this study, we report the construction of the first genetic library for the Tasmanian devil, a spleen cDNA library, and the isolation of full-length MHC Class I and Class II genes. We describe six unique Class II beta chain sequences from at least three loci, which belong to the marsupial Class II DA gene family. We have isolated 13 unique devil Class I sequences, representing at least seven Class I loci, two of which are most likely non-classical genes. The MHC Class I sequences from the devil have little heterogeneity, indicating recent divergence. The MHC genes described here are most likely involved in antigen presentation and are an important first step for studying MHC diversity and immune response in the devil.

  15. Expression of major histocompatibility complex class II and costimulatory molecules in oral carcinomas in vitro.

    PubMed

    Villarroel-Dorrego, Mariana; Speight, Paul M; Barrett, A William

    2005-01-01

    Recognition in the 1980 s that keratinocytes can express class II molecules of the Major Histocompatibility Complex (MHC) first raised the possibility that these cells might have an immunological function, and may even act as antigen presenting cells (APC). For effective T lymphocyte activation, APC require, in addition to MHC II, appropriate costimulatory signals. The aim of this study was to determine the expression of MHC class II and the co-stimulatory molecules CD40, CD80 and CD86 in keratinocytes derived from healthy oral mucosa and oral carcinomas. Using flow cytometry, it was confirmed that oral keratinocytes, switch on, expression of MHC class II molecules after stimulation with IFNgamma in vitro. All keratinocyte lines expressed CD40 constitutively; by contrast, CD80 and CD86 were universally absent. Loss of CD80 and CD86 may be one means whereby tumours escape immunological surveillance.

  16. Differential expression of MHC class I antigens on the placenta of the rat. A mechanism for the survival of the fetal allograft

    PubMed Central

    1987-01-01

    In some mating combinations in rats, there is a maternal antibody response to the maternal antigenic components of the placenta without any previous immunization of the mother. The highest response occurs in the WF (u) female mated to the DA (a) male, and it is against a unique MHC-encoded class I antigen, the Pa antigen, and not against the major allele-specific transplantation antigen of the DA strain, RT1.Aa. The development of mAbs to the Pa and Aa antigens allowed us to localize these antigens on the placenta and to explore the reason for the differential antibody response to them using immunohistochemical and biochemical techniques. Both antibodies reacted with the WF X DA placenta and stained the endovascular and interstitial trophoblast of the decidua, the basal trophoblast, Reichert's membrane, and the yolk sac epithelium, but they did not stain the labyrinthine trophoblast. Blocking studies showed that each antibody reacted with a separate molecule in the placenta. Anti-class II mAbs reactive with the a or u haplotype did not stain the WF X DA, DA X DA, or WF X WF placenta; hence, there are no class II antigens in the placenta. Electron microscopic studies of the semiallogeneic WF X DA placenta using the immunogold technique with both single- and double-labeling showed that only the Pa antigen was expressed on the surface of the basal trophoblast, but that both the Pa and Aa antigens were in the cytoplasm of these cells; neither antigen was found in the labyrinthine trophoblast. By contrast, the placenta from the syngeneic DA X DA mating expressed both the Pa and Aa antigens on the surface of the basal trophoblast as well as in the cytoplasm; neither antigen was found in the labyrinthine trophoblast. These observations were quantified morphometrically using electron photomicrographs of single- labeled tissues. Both the Pa and Aa antigens isolated from the plasma membrane of lymphocytes have heavy chains of 46 kD, but those antigens isolated from the

  17. Anti-class II antibodies in AIDS patients and AIDS-risk groups.

    PubMed Central

    de la Barrera, S; Fainboim, L; Lugo, S; Picchio, G R; Muchinik, G R; de Bracco, M M

    1987-01-01

    The specificity of anti-lymphocyte antibodies was evaluated in AIDS patients and in individuals at risk of AIDS [R-AIDS: male homosexuals (Ho) and haemophiliacs (He)]. Antibodies capable of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) against non-T cells and lymphoblastoid cell lines (P3HR-1K and Raji) were detected in AIDS patients and in R-AIDS with positive or negative human immune deficiency virus (HIV) serology. Anti-class II antigen specificity was revealed by experiments in which class II antigens on target cells were blocked with monoclonal anti-class II antibody (DA6,231) and the cytotoxic reaction induced by patient's sera was abolished. In contrast, ADCC was not impaired by preincubating the target cells with anti-class I monoclonal antibody (W6/32). Prevalence of antibodies to non-T cells was confirmed by standard C-mediated microlymphocytotoxicity. However, with this technique anti-T lymphocyte cytotoxicity was also observed in three AIDS patients with haemophilia. R-AIDS peripheral blood mononuclear cells (PBMC) were also cytotoxic against autologous non-T cells, and lysis was slightly increased by sensitization of the target cells with autologous serum. In addition to ADCC and C-mediated cytotoxicity, the specificity of anti-lymphocyte antibodies was assayed by their ability to interfere the binding of fluorescein-labelled anti-class II (HLA-DR) and anti-class I (W6/32) monoclonal antibodies to PBMC, non-T cells, P3HR-1K and Raji. Anti-class II specificity was confirmed, and antibody titres tended to be higher in Ho than in He R-AIDS, using non-T cells and Raji as targets. Higher titres of anti-class II antibodies in the Ho group could play a role in the different susceptibility of HIV-infected Ho when compared to HIV (+) He to develop AIDS. PMID:3501399

  18. Cell surface expression and function of an HLA class II molecule with class I domain configuration

    PubMed Central

    1993-01-01

    Recombinant major histocompatibility complex (MHC) class II molecules were expressed with extracellular polypeptide domains reorganized to form heavy (H) and light (L) chains (alpha 1-beta 1-beta 2 and alpha 2) analogous to class I. Accurate protein folding and dimerization is demonstrated by the ability of this 3+1-DR1 construct to bind class II- restricted peptides and stimulate CD4+ T cells. Cell surface expression of a functional class II molecule consisting of H and L chains supports the validity of current class II models and affirms the evolutionary relatedness of class I/II. MHC functions that differ between class I/II may be influenced by domain configuration, and the use of domain- shifted constructs will allow examination of this possibility. PMID:8340763

  19. Examination of serum class I antigen in liver-transplanted rats.

    PubMed Central

    Sumimoto, R; Shinomiya, T

    1991-01-01

    We examined the appearance of donor (DA) type class I antigen in the serum of rats that had received isogeneic (DA----DA) or allogeneic (DA----PVG, DA----BN, DA----LEW) liver transplants with or without cyclosporin A treatment, using two-site enzyme immunoassay. We also tested the serum titre of class I antigen in the normal DA rats with either 70% hepatectomy or cyclosporin A treatment, in order to clarify the relationship between the fluctuation in the serum titre of class I antigen in the recipient and the outcome of the transplanted liver graft. The suppression of liver graft rejection by cyclosporin A treatment significantly lowered the serum level of donor liver-derived class I antigen as compared with that of the recipient without cyclosporin A for a certain period. However, there was almost no correlation between the intensity of rejection of the liver graft and the serum level type class I among these allogeneic rejection and non-rejection liver transplantation combinations. The amount of donor-type class I antigen in the recipient's serum is dependent on whether the grafted liver is severely damaged following partial hepatectomy, whether the liver has associated biliary complications or ischaemic damage, or whether the liver has had absolute residual parenchymal cell volume or function following liver rejection. Our results suggest that the appearance of donor type class I antigen following liver transplantation is dependent on many factors, and therefore the titre of serum class 1 antigen may not always be a decisive indicator of liver graft rejection. PMID:2070555

  20. 40 CFR 144.19 - Transitioning from Class II to Class VI.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Transitioning from Class II to Class VI. (a) Owners or operators that are injecting carbon dioxide for the... geologic sequestration permit when there is an increased risk to USDWs compared to Class II operations. In...) Increase in carbon dioxide injection rates; (3) Decrease in reservoir production rates; (4) Distance...

  1. 40 CFR 144.19 - Transitioning from Class II to Class VI.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Transitioning from Class II to Class VI. (a) Owners or operators that are injecting carbon dioxide for the... geologic sequestration permit when there is an increased risk to USDWs compared to Class II operations. In...) Increase in carbon dioxide injection rates; (3) Decrease in reservoir production rates; (4) Distance...

  2. 40 CFR 144.19 - Transitioning from Class II to Class VI.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Transitioning from Class II to Class VI. (a) Owners or operators that are injecting carbon dioxide for the... geologic sequestration permit when there is an increased risk to USDWs compared to Class II operations. In...) Increase in carbon dioxide injection rates; (3) Decrease in reservoir production rates; (4) Distance...

  3. A Small Peptide (CEL-1000) Derived from the Beta-Chain of the Human Major Histocompatibility Complex Class II Molecule Induces Complete Protection Against Malaria in an Antigen-Independent Manner

    DTIC Science & Technology

    2004-07-01

    mice by conjugates of HGP -30 (peptide analog of HIV-1SF2 p17) and peptide seg- ments of human -2-microglobulin or MHC II chain. Vaccine 19:4750– 4759. VOL. 48, 2004 CEL-1000-INDUCED PROTECTION AGAINST MALARIA 2463

  4. Presence of third molar germs in orthodontic patients with class II/2 and class III malocclusions.

    PubMed

    Mady Maricić, Barbara; Legović, Mario; Slaj, Martina; Lapter Varga, Marina; Zuvić Butorac, Marta; Kapović, Miljenko

    2009-12-01

    The aim of this study was to determine the presence of third molar germs in patients with Class II/2 and Class III malocclusions. The study comprised 146 examinees from Zagreb and Istria. Examinees with Class II/2 malocclusions amounted to 77 and those with Class III 69. With regard to development of dentition the examinees were divided into two groups: Group I subjects with early mixed dentition (23 subjects with Class II/2 and 21 subjects with Class III), and Group II subjects with late mixed dentition (54 subjects with Class II/2 and 48 subjects with Class III). Assessments were made from panoramic radiographs and lateral cephalograms. The Pearson chi2-test and Fisher's exact test was used to determine statistical significance in differences. Assessments showed that third molar germs were present significantly more often in the upper jaw in Class II/2 (58% vs. 44%) and in the lower jaw in Class III (83% vs. 69%). In subjects with Class II/2 all third molar germs were present statistically more often in late mixed dentition, which was also determined for maxillary third molar germs in Class III. The presence of mandibular third molar germs in Class III examinees was almost equal in both periods of mixed dentitions. The study confirmed correlation between the presence of third molar germs and sagital maxillomandibular relationship and encourages investigation of the differences in calcifications of all permanent teeth in such malocclusions.

  5. A general model of invariant chain association with class II major histocompatibility complex proteins.

    PubMed Central

    Lee, C; McConnell, H M

    1995-01-01

    The binding of invariant chain to major histocompatibility complex (MHC) proteins is an important step in processing of MHC class II proteins and in antigen presentation. The question of how invariant chain can bind to all MHC class II proteins is central to understanding these processes. We have employed molecular modeling to predict the structure of class II-associated invariant chain peptide (CLIP)-MHC protein complexes and to ask whether the predicted mode of association could be general across all MHC class II proteins. CLIP fits identically into the MHC class II alleles HLA-DR3, I-Ak, I-Au, and I-Ad, with a consistent pattern of hydrogen bonds, contacts, and hydrophobic burial and without bad contacts. Our model predicts the burial of CLIP residues Met-91 and Met-99 in the deep P1 and P9 anchor pockets and other detailed interactions, which we have compared with available data. The predicted pattern of I-A allele-specific effects on CLIP binding is very similar to that observed experimentally by alanine-scanning mutations of CLIP. Together, these results indicate that CLIP may bind in a single, general way across products of MHC class II alleles. Images Fig. 1 Fig. 2 Fig. 3 PMID:7667280

  6. Molecular characterization of major histocompatibility complex class II alleles in wild tiger salamanders (Ambystoma tigrinum).

    PubMed

    Bos, David H; DeWoody, J Andrew

    2005-11-01

    Major histocompatibility complex (MHC) class II genes are usually among the most polymorphic in vertebrate genomes because of their critical role (antigen presentation) in immune response. Prior to this study, the MHC was poorly characterized in tiger salamanders (Ambystoma tigrinum), but the congeneric axolotl (Ambystoma mexicanum) is thought to have an unusual MHC. Most notably, axolotl class II genes lack allelic variation and possess a splice variant without a full peptide binding region (PBR). The axolotl is considered immunodeficient, but it is unclear how or to what extent MHC genetics and immunodeficiency are interrelated. To study the evolution of MHC genes in urodele amphibians, we describe for the first time an expressed polymorphic class II gene in wild tiger salamanders. We sequenced the PBR of a class II gene from wild A. tigrinum (n=33) and identified nine distinct alleles. Observed heterozygosity was 73%, and there were a total of 46 polymorphic sites, most of which correspond to amino acid positions that bind peptides. Patterns of nucleotide substitutions exhibit the signature of diversifying selection, but no recombination was detected. Not surprisingly, trans-species evolution of tiger salamander and axolotl class II alleles was apparent. We have no direct data on the immunodeficiency of tiger salamanders, but the levels of polymorphism in our study population should suffice to bind a variety of foreign peptides (unlike axolotls). Our tiger salamander data suggest that the monomorphism and immunodeficiencies associated with axolotl class II genes is a relic of their unique historical demography, not their phylogenetic legacy.

  7. 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

    USDA-ARS?s Scientific Manuscript database

    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...

  8. Enhanced Direct Major Histocompatibility Complex Class I Self-Antigen Presentation Induced by Chlamydia Infection.

    PubMed

    Cram, Erik D; Simmons, Ryan S; Palmer, Amy L; Hildebrand, William H; Rockey, Daniel D; Dolan, Brian P

    2015-11-23

    The direct major histocompatibility complex (MHC) class I antigen presentation pathway ensures intracellular peptides are displayed at the cellular surface for recognition of infected or transformed cells by CD8(+) cytotoxic T lymphocytes. Chlamydia spp. are obligate intracellular bacteria and, as such, should be targeted by CD8(+) T cells. It is likely that Chlamydia spp. have evolved mechanisms to avoid the CD8(+) killer T cell responses by interfering with MHC class I antigen presentation. Using a model system of self-peptide presentation which allows for posttranslational control of the model protein's stability, we tested the ability of various Chlamydia species to alter direct MHC class I antigen presentation. Infection of the JY lymphoblastoid cell line limited the accumulation of a model host protein and increased presentation of the model-protein-derived peptides. Enhanced self-peptide presentation was detected only when presentation was restricted to defective ribosomal products, or DRiPs, and total MHC class I levels remained unaltered. Skewed antigen presentation was dependent on a bacterial synthesized component, as evidenced by reversal of the observed phenotype upon preventing bacterial transcription, translation, and the inhibition of bacterial lipooligosaccharide synthesis. These data suggest that Chlamydia spp. have evolved to alter the host antigen presentation machinery to favor presentation of defective and rapidly degraded forms of self-antigen, possibly as a mechanism to diminish the presentation of peptides derived from bacterial proteins.

  9. Enhanced Direct Major Histocompatibility Complex Class I Self-Antigen Presentation Induced by Chlamydia Infection

    PubMed Central

    Cram, Erik D.; Simmons, Ryan S.; Palmer, Amy L.; Hildebrand, William H.; Rockey, Daniel D.

    2015-01-01

    The direct major histocompatibility complex (MHC) class I antigen presentation pathway ensures intracellular peptides are displayed at the cellular surface for recognition of infected or transformed cells by CD8+ cytotoxic T lymphocytes. Chlamydia spp. are obligate intracellular bacteria and, as such, should be targeted by CD8+ T cells. It is likely that Chlamydia spp. have evolved mechanisms to avoid the CD8+ killer T cell responses by interfering with MHC class I antigen presentation. Using a model system of self-peptide presentation which allows for posttranslational control of the model protein's stability, we tested the ability of various Chlamydia species to alter direct MHC class I antigen presentation. Infection of the JY lymphoblastoid cell line limited the accumulation of a model host protein and increased presentation of the model-protein-derived peptides. Enhanced self-peptide presentation was detected only when presentation was restricted to defective ribosomal products, or DRiPs, and total MHC class I levels remained unaltered. Skewed antigen presentation was dependent on a bacterial synthesized component, as evidenced by reversal of the observed phenotype upon preventing bacterial transcription, translation, and the inhibition of bacterial lipooligosaccharide synthesis. These data suggest that Chlamydia spp. have evolved to alter the host antigen presentation machinery to favor presentation of defective and rapidly degraded forms of self-antigen, possibly as a mechanism to diminish the presentation of peptides derived from bacterial proteins. PMID:26597986

  10. Nonlinkage of major histocompatibility complex class I and class II loci in bony fishes.

    PubMed

    Sato, A; Figueroa, F; Murray, B W; Málaga-Trillo, E; Zaleska-Rutczynska, Z; Sültmann, H; Toyosawa, S; Wedekind, C; Steck, N; Klein, J

    2000-02-01

    In tetrapods, the functional (classical) class I and class II B loci of the major histocompatibility complex (Mhc) are tightly linked in a single chromosomal region. In an earlier study, we demonstrated that in the zebrafish, Danio rerio, order Cypriniformes, the two classes are present on different chromosomes. Here, we show that the situation is similar in the stickleback, Gasterosteus aculeatus, order Gasterosteiformes, the common guppy, Poecilia reticulata, order Cyprinodontiformes, and the cichlid fish Oreochromis niloticus, order Perciformes. These data, together with unpublished results from other laboratories suggest that in all Euteleostei, the classical class I and class II B loci are in separate linkage groups, and that in at least some of these taxa, the class II loci are in two different groups. Since Euteleostei are at least as numerous as tetrapods, in approximately one-half of jawed vertebrates, the class I and class II regions are not linked.

  11. Sequence, distribution and chromosomal context of class I and class II pilin genes of Neisseria meningitidis identified in whole genome sequences

    PubMed Central

    2014-01-01

    Background Neisseria meningitidis expresses type four pili (Tfp) which are important for colonisation and virulence. Tfp have been considered as one of the most variable structures on the bacterial surface due to high frequency gene conversion, resulting in amino acid sequence variation of the major pilin subunit (PilE). Meningococci express either a class I or a class II pilE gene and recent work has indicated that class II pilins do not undergo antigenic variation, as class II pilE genes encode conserved pilin subunits. The purpose of this work was to use whole genome sequences to further investigate the frequency and variability of the class II pilE genes in meningococcal isolate collections. Results We analysed over 600 publically available whole genome sequences of N. meningitidis isolates to determine the sequence and genomic organization of pilE. We confirmed that meningococcal strains belonging to a limited number of clonal complexes (ccs, namely cc1, cc5, cc8, cc11 and cc174) harbour a class II pilE gene which is conserved in terms of sequence and chromosomal context. We also identified pilS cassettes in all isolates with class II pilE, however, our analysis indicates that these do not serve as donor sequences for pilE/pilS recombination. Furthermore, our work reveals that the class II pilE locus lacks the DNA sequence motifs that enable (G4) or enhance (Sma/Cla repeat) pilin antigenic variation. Finally, through analysis of pilin genes in commensal Neisseria species we found that meningococcal class II pilE genes are closely related to pilE from Neisseria lactamica and Neisseria polysaccharea, suggesting horizontal transfer among these species. Conclusions Class II pilins can be defined by their amino acid sequence and genomic context and are present in meningococcal isolates which have persisted and spread globally. The absence of G4 and Sma/Cla sequences adjacent to the class II pilE genes is consistent with the lack of pilin subunit variation in these

  12. HLA class II haplotypes differentiate between the adult autoimmune polyglandular syndrome types II and III.

    PubMed

    Flesch, B K; Matheis, N; Alt, T; Weinstock, C; Bux, J; Kahaly, G J

    2014-01-01

    Genetics of the adult autoimmune polyglandular syndrome (APS) is poorly understood. The aim of this study was to gain further insight into the genetics of the adult APS types. SITE: The study was conducted at a university referral center. The human leukocyte antigen (HLA) class II alleles, haplotypes, and genotypes were determined in a large cohort of patients with APS, autoimmune thyroid disease (AITD), and type 1 diabetes and in healthy controls by the consistent application of high-resolution typing at a four-digit level. Comparison of the allele and haplotype frequencies significantly discriminated patients with APS vs AITD and controls. The HLA class II alleles DRB1*03:01 *04:01, DQA1*03:01, *05:01, DQB1*02:01, and *03:02 were observed more frequently (P<.001) in APS than in AITD and controls, whereas the alleles DRB1*15:01, DQB1*03:01, and *06:02 were underrepresented in APS vs AITD (Pc<.001) and controls (Pc<.01), respectively. The DRB1*03:01-DQA1*05:01-DQB1*02:01 (DR3-DQ2) and DRB1*04:01-DQA1*03:01:DQB1*03:02 (DRB1*04:01-DQ8) haplotypes were overrepresented in APS (Pc<.001). Combination of both haplotypes to a genotype was highly prevalent in APS vs AITD and controls (Pc<.001). Dividing the APS collective into those with Addison's disease (APS type II) and those without Addison's disease but including type 1 diabetes and AITD (APS type III) demonstrated DR3-DQ2/DRB1*04:01-DQ8 as a susceptibility genotype in APS III (Pc<.001), whereas the DR3-DQ2/DRB1*04:04-DQ8 genotype correlated with APS II (Pc<.001). The haplotypes DRB1*11:01-DQA1*05:05-DQB1*03:01 and DRB1*15:01-DQA1*01:02-DQB1*06:02 are protective in APS III but not in type II (Pc<.01). HLA class II haplotypes differentiate between the adult APS types II and III. Susceptible haplotypes favor the development of polyglandular autoimmunity in patients with AITD.

  13. 25 CFR 522.10 - Individually owned class II and class III gaming operations other than those operating on...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Individually owned class II and class III gaming... GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.10 Individually owned class II and class III...

  14. 25 CFR 522.10 - Individually owned class II and class III gaming operations other than those operating on...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Individually owned class II and class III gaming... GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.10 Individually owned class II and class III...

  15. 25 CFR 522.10 - Individually owned class II and class III gaming operations other than those operating on...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Individually owned class II and class III gaming... GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.10 Individually owned class II and class...

  16. 25 CFR 522.10 - Individually owned class II and class III gaming operations other than those operating on...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Individually owned class II and class III gaming... GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.10 Individually owned class II and class...

  17. 78 FR 37114 - Self-Regulation of Class II Gaming

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... National Indian Gaming Commission 25 CFR Part 518 RIN 3141-AA44 Self-Regulation of Class II Gaming AGENCY... concerning the issuance of certificates for tribal self-regulation of Class II gaming: To correct a section... on the same day that it receives a tribe's response to the Office of Self Regulation's...

  18. 77 FR 4714 - Self-Regulation of Class II Gaming

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-31

    ... National Indian Gaming Commission 25 CFR Part 518 RIN 3141-AA44 Self-Regulation of Class II Gaming AGENCY... proposes to amend the NIGC's self-regulation regulations to tailor the self-regulating qualifying criteria to a tribe's regulation of class II gaming activity and more clearly define and streamline the...

  19. [Does dental class II division 2 predispose to temporomandibular disorders?].

    PubMed

    Zuaiter, Shireen; Robin, Olivier; Gebeile-Chauty, Sarah; Raberin, Monique

    2013-09-01

    Because of its anatomical/physiological characteristics, the Class II division 2 (class II, div. 2) is one of the malocclusions considered as a possible risk factor for Temporomandibular disorders (TMD). A literature review was conducted from the electronic databases of Medline and Elsevier Masson, through the year 2010, in order to clarify the relationships that may exist between Class II division 2 and TMD. This research helped identify 50 articles: 7 articles specifically concerned the Class II div. 2, 37 articles concerned some of the characteristics of the Class II div. 2, considered individually (Class II, deep bite, retroclined maxillary incisors, mandibular retrognathism) and 6 articles orthodontic treatment. From the conclusions of these studies, the Class II, div. 2 does not appear to represent a significant risk factor for TMD. The clearest association would involve mandibular retrognathism and the risk of articular disk displacement. However, given the low number of articles published on this topic, the methodological variability and the contradictory results, it is difficult to identify reliable conclusions and, consequently, the therapeutic indications for the treatment of Class II div. 2 patients with TMD.

  20. Efficiency of Class I and Class II malocclusion treatment with four premolar extractions

    PubMed Central

    JANSON, Guilherme; NAKAMURA, Alexandre; BARROS, Sérgio Estelita; BOMBONATTI, Roberto; CHIQUETO, Kelly

    2014-01-01

    Four premolar extractions is a successful protocol to treat Class I malocclusion, but it is a less efficient way when compared with other Class II treatment protocols. Objective: The objective of this study was to evaluate the influence of anteroposterior discrepancy on the success of four premolar extractions protocol. For that, treatment efficiency of Class I and complete Class II malocclusions, treated with four premolar extractions were compared. Methods: A sample of 107 records from 75 Class I (mean age of 13.98 years - group 1) and 32 Class II (mean age of 13.19 years - group 2) malocclusion patients treated with four premolar extractions was selected. The initial and final occlusal status of each patient was evaluated on dental casts with the PAR index. The treatment time was calculated based on the clinical charts, and the treatment efficiency was obtained by the ratio between the percentage of PAR reduction and treatment time. The PAR index and its components, the treatment time and the treatment efficiency of the groups were statistically compared with t tests and Mann-Whitney U-test. Results: The Class II malocclusion patients had a greater final PAR index than Class I malocclusion patients, and similar duration (Class I - 28.95 mo. and Class II - 28.10 mo.) and treatment efficiency. Conclusion: The treatment of the complete Class II malocclusion with four premolar extractions presented worse occlusal results than Class I malocclusion owing to incomplete molar relationship correction. PMID:24918660

  1. MHC Class I-Related Antigen-Processing Machinery Component Defects in Feline Mammary Carcinoma1

    PubMed Central

    Favole, Alessandra; Cascio, Paolo; Cerruti, Fulvia; Sereno, Alessandra; Tursi, Massimiliano; Tomatis, Alessandro; Beffa, Cristina Della; Ferrone, Soldano; Bollo, Enrico

    2012-01-01

    Defects in HLA class I antigen-processing machinery (APM) component expression and/or function are frequent in human tumors. These defects may provide tumor cells with a mechanism to escape from recognition and destruction by HLA class I antigen-restricted, tumor antigen-specific cytotoxic T cells. However, expression and functional properties of MHC class I antigens and APM components in malignant cells in other animal species have been investigated to a limited extent. However, this information can contribute to our understanding of the mechanisms underlying the association of MHC class I antigen and APM component defects with malignant transformation of cells and to identify animal models to validate targeted therapies to correct these defects. To overcome this limitation in the present study, we have investigated the expression of the catalytic subunits of proteasome (Y, X, and Z) and of immunoproteasome (LMP2, LMP7, and LMP10) as well as of MHC class I heavy chain (HC) in 25 primary feline mammary carcinomas (FMCs) and in 23 matched healthy mammary tissues. We found a reduced expression of MHC class I HC and of LMP2 and LMP7 in tumors compared with normal tissues. Concordantly, proteasomal cleavage specificities in extracts from FMCs were different from those in healthy tissues. In addition, correlation analysis showed that LMP2 and LMP7 were concordantly expressed in FMCs, and their expression was significantly correlated with that of MHC class I HC. The abnormalities we have found in the APM in FMCs may cause a defective processing of some tumor antigens. PMID:22348176

  2. Selective abrogation of major histocompatibility complex class II expression on extrahematopoietic cells in mice lacking promoter IV of the class II transactivator gene.

    PubMed

    Waldburger, J M; Suter, T; Fontana, A; Acha-Orbea, H; Reith, W

    2001-08-20

    MHC class II (MHCII) molecules play a pivotal role in the induction and regulation of immune responses. The transcriptional coactivator class II transactivator (CIITA) controls MHCII expression. The CIITA gene is regulated by three independent promoters (pI, pIII, pIV). We have generated pIV knockout mice. These mice exhibit selective abrogation of interferon (IFN)-gamma-induced MHCII expression on a wide variety of non-bone marrow-derived cells, including endothelia, epithelia, astrocytes, and fibroblasts. Constitutive MHCII expression on cortical thymic epithelial cells, and thus positive selection of CD4(+) T cells, is also abolished. In contrast, constitutive and inducible MHCII expression is unaffected on professional antigen-presenting cells, including B cells, dendritic cells, and IFN-gamma-activated cells of the macrophage lineage. pIV(-/-) mice have thus allowed precise definition of CIITA pIV usage in vivo. Moreover, they represent a unique animal model for studying the significance and contribution of MHCII-mediated antigen presentation by nonprofessional antigen-presenting cells in health and disease.

  3. Class I HLA antigens in spondyloarthropathy: observations in Alaskan Eskimo patients and controls.

    PubMed

    Boyer, G S; Templin, D W; Bowler, A; Lawrence, R C; Heyse, S P; Everett, D F; Cornoni-Huntley, J C; Goring, W P

    1997-03-01

    To assess the role of HLA-B27 and other class I histocompatibility antigens in overall risk and clinical manifestations of spondyloarthropathy (SpA) in Alaskan Eskimos. Class I antigens were studied in 104 patients with SpA and in 111 controls. The frequencies of HLA-A, B, and Cw antigens were determined in patients with SpA with various clinical manifestations and compared to frequencies observed in controls. Only HLA-B27 differed significantly in cases and controls. Except for B27, no association of particular antigens with specific syndromes or disease features was found. Patients with B27 had more extraarticular manifestations than patients who lacked B27 antigen. Patients putatively homozygous for B27 did not appear to have more severe disease than those who were heterozygotic. B27 was most closely associated with ankylosing spondylitis [odds ratio (OR) = 210], less so with reactive arthritis (OR = 12.9) and undifferentiated SpA (OR = 4.6). Observations in other population groups that implicated B27 cross reactive group (CREG) and other A, B, and Cw antigens as risk factors for developing SpA were not confirmed in Alaskan Eskimos. Nor were CREG or other B antigens either alone or in combination with B27 associated with specific clinical syndromes. Only HLA-B27 was strongly associated with disease and with extraarticular manifestations.

  4. Generation of MHC class II:peptide ligands for CD4 T cell allorecognition of MHC Class II molecules

    PubMed Central

    Leddon, Scott A.; Sant, Andrea J.

    2011-01-01

    Purpose of review The molecular and cellular mechanisms that underlie allorecognition of MHC class II molecules has been the subject much debate and experimentation in recent decades. In this review, we discuss several aspects of MHC class II structure, peptide acquisition and TcR-MHC:peptide interactions that have particular relevance to recognition of cells bearing allogeneic class II molecules. Recent findings First, MHC polymorphism is heavily biased toward those amino acids that influence stable peptide binding by MHC class II. Second, the peptide repertoire presented by class II molecules is highly diverse and can be edited substantially by the molecular catalyst HLA-DM and by tissue-specific expression of HLA-DO, stress and cytokines. Third, T cell receptor docking onto MHC peptide typically involves substantial contacts with the bound peptide in the MHC class II molecule. Finally, there is increasing evidence that T cell recognition of MHC is in part germline-encoded through T cell receptor V region contacts with MHC class II alpha helices. Summary Together, these conclusions support the view that allorecognition of MHC class II molecules is likely to parallel key aspects of conventional CD4 T cell recognition, with allele-dependent variation in peptide representation accounting in large part for the high precursor frequency of alloreactive CD4 T cells PMID:20616724

  5. Class I major histocompatibility complex antigens and tumor ploidy in breast and bronchogenic carcinomas.

    PubMed

    Redondo, M; Concha, A; Ruiz-Cabello, F; Morell, M; Esteban, F; Talavera, P; Garrido, F

    1997-01-01

    We determined the frequency of expression of the major histocompatibility complex antigens HLA-A,B,C in tumor cells from 207 primary tumor lesions of breast and bronchogenic carcinomas, to see if the expression of theses antigens was linked with several clinicopathological parameters associated with tumor aggressivity, such as abnormal cellular DNA content. We compared tumor tissues with nonneoplastic tissues and tissues from 15 benign breast lesions. HLA class I expressor and nonexpressor tumor cells were determined by using immunohistochemical stains (PAP and APAAP methods) and antibodies against these antigens. Reduction of HLA class I antigen was detected in 65 tumors (31.7%) and was significantly associated with poor tumor differentiation and abnormal cellular DNA content (p < 0.001). These characteristics might define a group of aggressive tumors in which the decrease of HLA class I antigens would enable tumor cells to avoid eliciting host immune responses. On the other hand, the altered regulatory mechanisms, of tumors with abnormal cellular DNA content, might modulate the expression of HLA class I molecules.

  6. Large bowel carcinoma-specific antigens detected by the lectin, Griffonia simplicifolia agglutinin-II.

    PubMed

    Nakayama, J; Katsuyama, T; Ono, K; Honda, T; Akamatsu, T; Hattori, H

    1985-11-01

    A lectin reactivity specific to human bowel carcinoma is reported. Twenty-six cases of carcinoma of the large intestine were examined. Normal as well as transitional mucosa and carcinoma tissues were removed from surgical specimens, and paraffin sections were stained with a battery of histochemical methods to characterize glycoconjugates, including high iron diamine-Alcian blue pH 2.5, modified PAS reaction to detect various sialic acids, paradoxical concanavalin A (Con A) staining, and stainings with 10 species of lectins labeled with horseradish peroxidase (HRP). Among the techniques employed, only Griffonia simplicifolia agglutinin-II (GS-II, specific to glucosamine)-HRP staining revealed highly selective affinity to the carcinoma tissues; the apical surface of the carcinoma cells stained most intensely. GS-II reactivity of the cells persisted after prior periodate oxidation, but was significantly enhanced by neuraminidase digestion. Comparison with two other lectin stainings with the same sugar specificity, viz. paradoxical concanavalin A staining and wheat germ agglutinin (WGA)-HRP staining, showed that the GS-II reactive sites lacked class III Con A reactivity but were possibly included in WGA reactive sites. The GS-II-HRP staining should be helpful in the identification of carcinoma tissue and for analysis of carcinoma-associated antigens.

  7. The Biochemical Characterization of Plasma Class I Human Leukocyte Antigens (HLA)

    DTIC Science & Technology

    1989-12-01

    Strachan T: Molecular Genetics and Polymorphism of Class I HLA Antigens. Br Med Bull 43:1-14, 1987 52. Duquesnoy FJ, Trucco M: Genetic Basis of Cell...Antibodies to Group A Erythrocytes, HLA and Other Human Cell Surface Antigens-New Tools for Genetic Analysis. Cell 14:9-30, 1978 31. Brodsky FM...Bouhallier 0, Merdrignac G, Genetet B, Turmel P, Charron DJ: New Class I in Man: Serological and Molecular Characterization. Human Immuno. 17:3-20, 1986 58

  8. Management of Class II malocclusion with ectopic maxillary canines

    PubMed Central

    Mascarenhas, Rohan; Parveen, Shahista; Ansari, Tariq Aziz

    2015-01-01

    Correction of Class II relationship, deep bite and ectopically erupting canines is an orthodontic challenge for the clinician. A 13-year-old male patient presented with Class II malocclusion, ectopically erupting canines, and cross bite with maxillary left lateral incisor. He was treated with a combination of Headgear, Forsus™ fatigue resistant device [FFRD] with fixed mechanotherapy for the management of space deficiency and correction of Class II malocclusions. Headgear was used to distalize upper first molars and also to prevent further downward and forward growth of the maxilla. Then Forsus™ FFRD was used for the advancement of the mandible. The molar and canine relationship were corrected from a Class II to a Class I. The objectives were to establish good occlusion and enable eruption of unerupted canines. All these objectives were achieved and remained stable. PMID:26097371

  9. Differential effect of HLA class-I versus class-II transgenes on human T and B cell reconstitution and function in NRG mice

    PubMed Central

    Majji, Sai; Wijayalath, Wathsala; Shashikumar, Soumya; Pow-Sang, Luis; Villasante, Eileen; Brumeanu, Teodor D.; Casares, Sofia

    2016-01-01

    Humanized mice expressing Human Leukocyte Antigen (HLA) class I or II transgenes have been generated, but the role of class I vs class II on human T and B cell reconstitution and function has not been investigated in detail. Herein we show that NRG (NOD.RagKO.IL2RγcKO) mice expressing HLA-DR4 molecules (DRAG mice) and those co-expressing HLA-DR4 and HLA-A2 molecules (DRAGA mice) did not differ in their ability to develop human T and B cells, to reconstitute cytokine-secreting CD4 T and CD8 T cells, or to undergo immunoglobulin class switching. In contrast, NRG mice expressing only HLA-A2 molecules (A2 mice) reconstituted lower numbers of CD4 T cells but similar numbers of CD8 T cells. The T cells from A2 mice were deficient at secreting cytokines, and their B cells could not undergo immunoglobulin class switching. The inability of A2 mice to undergo immunoglobulin class switching is due to deficient CD4 helper T cell function. Upon immunization, the frequency and cytotoxicity of antigen-specific CD8 T cells in DRAGA mice was significantly higher than in A2 mice. The results indicated a multifactorial effect of the HLA-DR4 transgene on development and function of human CD4 T cells, antigen-specific human CD8 T cells, and immunoglobulin class switching. PMID:27323875

  10. Subtle conformational changes induced in major histocompatibility complex class II molecules by binding peptides.

    PubMed

    Chervonsky, A V; Medzhitov, R M; Denzin, L K; Barlow, A K; Rudensky, A Y; Janeway, C A

    1998-08-18

    Intracellular trafficking of major histocompatibility complex (MHC) class II molecules is characterized by passage through specialized endocytic compartment(s) where antigenic peptides replace invariant chain fragments in the presence of the DM protein. These changes are accompanied by structural transitions of the MHC molecules that can be visualized by formation of compact SDS-resistant dimers, by changes in binding of mAbs, and by changes in T cell responses. We have observed that a mAb (25-9-17) that is capable of staining I-Ab on the surface of normal B cells failed to interact with I-Ab complexes with a peptide derived from the Ealpha chain of the I-E molecule but bound a similar covalent complex of I-Ab with the class II binding fragment (class II-associated invariant chain peptides) of the invariant chain. Moreover, 25-9-17 blocked activation of several I-Ab-reactive T cell hybridomas but failed to block others, suggesting that numerous I-Ab-peptide complexes acquire the 25-9-17(+) or 25-9-17(-) conformation. Alloreactive T cells were also able to discriminate peptide-dependent variants of MHC class II molecules. Thus, peptides impose subtle structural transitions upon MHC class II molecules that affect T cell recognition and may thus be critical for T cell selection and autiommunity.

  11. Molecular analysis of HLA class II genes in Goodpasture's disease.

    PubMed

    Burns, A P; Fisher, M; Li, P; Pusey, C D; Rees, A J

    1995-02-01

    A molecular analysis of HLA class II genes was undertaken in order to characterize the previously reported association between HLA-DR2 and glomerulonephritis caused by antibodies to glomerular basement membrane (Goodpasture's disease). Genomic DNA was prepared from 53 patients with Goodpasture's disease and analysed by: (i) Southern blotting using cDNA probes to DRB, DQA and DQB genes, after digestion with TaqI endonuclease; (ii) allele-specific oligonucleotide probing of specifically amplified DNA; and (iii) nucleotide sequencing of relevant alleles. The patients had a greatly increased frequency of DRw15 (a subspecificity of DR2) which was present in 75.5% of patients and 31% of controls (p < 0.0001). The frequency of DR4 was also increased, especially in patients without DRw15. Overall, 90.5% of the patients had either DRw15 or DR4. In contrast, the frequency of DR1 was significantly reduced (patients 5.6%, controls 20.7%, p < 0.01). Differences in the frequencies of DQA and DQB alleles could all be explained by linkage disequilibrium. Nucleotide sequences of relevant alleles were identical to those previously published. Comparison of derived amino acid sequences of expressed DR beta chains showed that the DR beta chains of DRw15 and DR4 shared a six-amino-acid motif from positions 26-31, that included four polymorphic amino acids none of which are shared with DR1. A sequence-specific oligonucleotide detected this amino-acid motif in 45/49 (91.8%) patients tested. Thus, this particular motif, which lies on the floor of the antigen binding groove, has a stronger association with Goodpasture's disease than any individual allele, and may be of pathogenic significance.

  12. HLA-G and MHC Class II Protein Expression in Diffuse Large B-Cell Lymphoma.

    PubMed

    Jesionek-Kupnicka, Dorota; Bojo, Marcin; Prochorec-Sobieszek, Monika; Szumera-Ciećkiewicz, Anna; Jabłońska, Joanna; Kalinka-Warzocha, Ewa; Kordek, Radzisław; Młynarski, Wojciech; Robak, Tadeusz; Warzocha, Krzysztof; Lech-Maranda, Ewa

    2016-06-01

    The expression of human leukocyte antigen-G (HLA-G) and HLA class II protein was studied by immunohistochemical staining of lymph nodes from 148 patients with diffuse large B-cell lymphoma (DLBCL) and related to the clinical course of the disease. Negative HLA-G expression was associated with a lower probability of achieving a complete remission (p = 0.04). Patients with negative HLA-G expression tended towards a lower 3-year overall survival (OS) rate compared to those with positive expression of HLA-G (p = 0.08). When restricting the analysis to patients receiving chemotherapy with rituximab, the estimated 3-year OS rate of patients with positive HLA-G expression was 73.3 % compared with 47.5 % (p = 0.03) in those with negative expression. Patients with negative HLA class II expression presented a lower 3-year OS rate compared to subjects with positive expression (p = 0.04). The loss of HLA class II expression (p = 0.05) and belonging to the intermediate high/high IPI risk group (p = 0.001) independently increased the risk of death. HLA class II expression also retained its prognostic value in patients receiving rituximab; the 3-year OS rate was 65.3 % in patients with positive HLA class II expression versus 29.6 % (p = 0.04) in subjects that had loss of HLA class II expression. To our knowledge, for the first time, the expression of HLA-G protein in DLBCL and its association with the clinical course of the disease was demonstrated. Moreover, the link between losing HLA class II protein expression and poor survival of patients treated with immunochemotherapy was confirmed.

  13. Identification of MHC class II restricted T-cell-mediated reactivity against MHC class I binding Mycobacterium tuberculosis peptides.

    PubMed

    Wang, Mingjun; Tang, Sheila T; Stryhn, Anette; Justesen, Sune; Larsen, Mette V; Dziegiel, Morten H; Lewinsohn, David M; Buus, Søren; Lund, Ole; Claesson, Mogens H

    2011-04-01

    Major histocompatibility complex (MHC) class I restricted cytotoxic T lymphocytes (CTL) are known to play an important role in the control of Mycobacterium tuberculosis infection so identification of CTL epitopes from M. tuberculosis is of importance for the development of effective peptide-based vaccines. In the present work, bioinformatics technology was employed to predict binding motifs of 9mer peptides derived from M. tuberculosis for the 12 HLA-I supertypes. Subsequently, the predicted peptides were synthesized and assayed for binding to HLA-I molecules in a biochemically based system. The antigenicity of a total of 157 peptides with measured affinity for HLA-I molecules of K(D) ≤ 500 nM were evaluated using peripheral blood T cells from strongly purified protein derivative reactive healthy donors. Of the 157 peptides, eight peptides (5%) were found to induce T-cell responses. As judged from blocking with HLA class I and II subtype antibodies in the ELISPOT assay culture, none of the eight antigenic peptides induced HLA class I restricted CD8(+) T-cell responses. Instead all responses were blocked by pan-HLA class II and anti-HLA-DR antibodies. In addition, CD4(+) T-cell depletion before the 10 days of expansion, resulted in total loss of reactivity in the ELISPOT culture for most peptide specificities. FACS analyses with intracellular interferon-γ staining of T cells expanded in the presence of M. tuberculosis peptides confirmed that the responsive cells were indeed CD4(+). In conclusion, T-cell immunity against HLA-I binding 9mer M. tuberculosis-derived peptides might in many cases turn out to be mediated by CD4(+) T cells and restricted by HLA-II molecules. The use of 9mer peptides recognized by both CD8(+) and CD4(+) T cells might be of importance for the development of future M. tuberculosis peptide-based vaccines.

  14. Dental archforms in dentoalveolar Class I, II and III.

    PubMed

    Slaj, Martina; Spalj, Stjepan; Pavlin, Dubravko; Illes, Davor; Slaj, Mladen

    2010-09-01

    To test the hypothesis that no differences exist in dental arch dimensions between dentoalveolar Classes I, II, and III, and between male and female subjects, as measured on virtual three-dimensional (3D) models. Samples included randomly selected plaster dental casts of 137 white patients (43 Class I, 50 Class II, and 44 Class III) from the Department of Orthodontics, School of Dental Medicine, University of Zagreb, Croatia. Dental models were scanned and digitized using ATOS II SO ("Small Objects") scanning technology (GOM mbH, Braunschweig, Germany). Eight linear and two proportional measurements were calculated for both upper and lower dental arches. In men, a significant difference in the upper dental arch was present in the incisor region, and in the lower dental arch, differences were found in intercanine and intermolar widths (P < .05). Significant differences were noted between male groups in the upper molar depth dimension (P = .022) and in the lower molar and canine depth dimensions (P < .05). Class III males had the greatest lower molar and canine width/depth ratios and the smallest lower canine depth/molar depth ratio. Class III women had wider and shorter mandibular arches when compared with Class I and Class II females. The hypothesis was rejected. The dimensions of the dental arches are related to gender and to dentoalveolar class. Class I and II subjects have similar dimensions of maxillary dental arch, but Class II subjects have a transverse deficit in the mandible. In Class III subjects, the maxillary dental arch is insufficient in transverse and sagittal dimensions, and the mandibular arch dominates in the transverse but not in the sagittal dimension.

  15. Archform Comparisons between Skeletal Class II and III Malocclusions

    PubMed Central

    Jiang, JiuHui; Xu, TianMin; Li, CuiYing

    2014-01-01

    The purpose of this cross-sectional research was to explore the relationship of the mandibular dental and basal bone archforms between severe Skeletal Class II (SC2) and Skeletal Class III (SC3) malocclusions. We also compared intercanine and intermolar widths in these two malocclusion types. Thirty-three virtual pretreatment mandibular models (Skeletal Class III group) and Thirty-five Skeletal Class II group pretreatment models were created with a laser scanning system. FA (the midpoint of the facial axis of the clinical crown)and WALA points (the most prominent point on the soft-tissue ridge)were employed to produce dental and basal bone archforms, respectively. Gained scatter diagrams of the samples were processed by nonlinear regression analysis via SPSS 17.0. The mandibular dental and basal bone intercanine and intermolar widths were significantly greater in the Skeletal Class III group compared to the Skeletal Class II group. In both groups, a moderate correlation existed between dental and basal bone arch widths in the canine region, and a high correlation existed between dental and basal bone arch widths in the molar region. The coefficient of correlation of the Skeletal Class III group was greater than the Skeletal Class II group. Fourth degree, even order power functions were used as best-fit functions to fit the scatter plots. The radius of curvature was larger in Skeletal Class III malocclusions compared to Skeletal Class II malocclusions (rWALA3>rWALA2>rFA3>rFA2). In conclusion, mandibular dental and basal intercanine and intermolar widths were significantly different between the two groups. Compared with Skeletal Class II subjects, the mandibular archform was more flat for Skeletal Class III subjects. PMID:24971597

  16. Archform comparisons between skeletal class II and III malocclusions.

    PubMed

    Zou, Wei; Wu, JiaQi; Jiang, JiuHui; Xu, TianMin; Li, CuiYing

    2014-01-01

    The purpose of this cross-sectional research was to explore the relationship of the mandibular dental and basal bone archforms between severe Skeletal Class II (SC2) and Skeletal Class III (SC3) malocclusions. We also compared intercanine and intermolar widths in these two malocclusion types. Thirty-three virtual pretreatment mandibular models (Skeletal Class III group) and Thirty-five Skeletal Class II group pretreatment models were created with a laser scanning system. FA (the midpoint of the facial axis of the clinical crown)and WALA points (the most prominent point on the soft-tissue ridge)were employed to produce dental and basal bone archforms, respectively. Gained scatter diagrams of the samples were processed by nonlinear regression analysis via SPSS 17.0. The mandibular dental and basal bone intercanine and intermolar widths were significantly greater in the Skeletal Class III group compared to the Skeletal Class II group. In both groups, a moderate correlation existed between dental and basal bone arch widths in the canine region, and a high correlation existed between dental and basal bone arch widths in the molar region. The coefficient of correlation of the Skeletal Class III group was greater than the Skeletal Class II group. Fourth degree, even order power functions were used as best-fit functions to fit the scatter plots. The radius of curvature was larger in Skeletal Class III malocclusions compared to Skeletal Class II malocclusions (rWALA3>rWALA2>rFA3>rFA2). In conclusion, mandibular dental and basal intercanine and intermolar widths were significantly different between the two groups. Compared with Skeletal Class II subjects, the mandibular archform was more flat for Skeletal Class III subjects.

  17. Structural basis for nonneutralizing antibody competition at antigenic site II of the respiratory syncytial virus fusion protein

    PubMed Central

    Mousa, Jarrod J.; Sauer, Marion F.; Sevy, Alexander M.; Finn, Jessica A.; Alvarado, Gabriela; King, Hannah G.; Loerinc, Leah B.; Fong, Rachel H.; Doranz, Benjamin J.; Correia, Bruno E.; Kalyuzhniy, Oleksandr; Wen, Xiaolin; Jardetzky, Theodore S.; Schief, William R.; Ohi, Melanie D.; Meiler, Jens

    2016-01-01

    Palivizumab was the first antiviral monoclonal antibody (mAb) approved for therapeutic use in humans, and remains a prophylactic treatment for infants at risk for severe disease because of respiratory syncytial virus (RSV). Palivizumab is an engineered humanized version of a murine mAb targeting antigenic site II of the RSV fusion (F) protein, a key target in vaccine development. There are limited reported naturally occurring human mAbs to site II; therefore, the structural basis for human antibody recognition of this major antigenic site is poorly understood. Here, we describe a nonneutralizing class of site II-specific mAbs that competed for binding with palivizumab to postfusion RSV F protein. We also describe two classes of site II-specific neutralizing mAbs, one of which escaped competition with nonneutralizing mAbs. An X-ray crystal structure of the neutralizing mAb 14N4 in complex with F protein showed that the binding angle at which human neutralizing mAbs interact with antigenic site II determines whether or not nonneutralizing antibodies compete with their binding. Fine-mapping studies determined that nonneutralizing mAbs that interfere with binding of neutralizing mAbs recognize site II with a pose that facilitates binding to an epitope containing F surface residues on a neighboring protomer. Neutralizing antibodies, like motavizumab and a new mAb designated 3J20 that escape interference by the inhibiting mAbs, avoid such contact by binding at an angle that is shifted away from the nonneutralizing site. Furthermore, binding to rationally and computationally designed site II helix–loop–helix epitope-scaffold vaccines distinguished neutralizing from nonneutralizing site II antibodies. PMID:27791117

  18. Structural basis for nonneutralizing antibody competition at antigenic site II of the respiratory syncytial virus fusion protein.

    PubMed

    Mousa, Jarrod J; Sauer, Marion F; Sevy, Alexander M; Finn, Jessica A; Bates, John T; Alvarado, Gabriela; King, Hannah G; Loerinc, Leah B; Fong, Rachel H; Doranz, Benjamin J; Correia, Bruno E; Kalyuzhniy, Oleksandr; Wen, Xiaolin; Jardetzky, Theodore S; Schief, William R; Ohi, Melanie D; Meiler, Jens; Crowe, James E

    2016-11-01

    Palivizumab was the first antiviral monoclonal antibody (mAb) approved for therapeutic use in humans, and remains a prophylactic treatment for infants at risk for severe disease because of respiratory syncytial virus (RSV). Palivizumab is an engineered humanized version of a murine mAb targeting antigenic site II of the RSV fusion (F) protein, a key target in vaccine development. There are limited reported naturally occurring human mAbs to site II; therefore, the structural basis for human antibody recognition of this major antigenic site is poorly understood. Here, we describe a nonneutralizing class of site II-specific mAbs that competed for binding with palivizumab to postfusion RSV F protein. We also describe two classes of site II-specific neutralizing mAbs, one of which escaped competition with nonneutralizing mAbs. An X-ray crystal structure of the neutralizing mAb 14N4 in complex with F protein showed that the binding angle at which human neutralizing mAbs interact with antigenic site II determines whether or not nonneutralizing antibodies compete with their binding. Fine-mapping studies determined that nonneutralizing mAbs that interfere with binding of neutralizing mAbs recognize site II with a pose that facilitates binding to an epitope containing F surface residues on a neighboring protomer. Neutralizing antibodies, like motavizumab and a new mAb designated 3J20 that escape interference by the inhibiting mAbs, avoid such contact by binding at an angle that is shifted away from the nonneutralizing site. Furthermore, binding to rationally and computationally designed site II helix-loop-helix epitope-scaffold vaccines distinguished neutralizing from nonneutralizing site II antibodies.

  19. The simple class II and class III corrector: three case reports.

    PubMed

    Spary, David John; Little, Rachel Ann

    2015-03-01

    This article illustrates three case reports which describe a very simple appliance that is used to correct both class II and class III buccal segments. A class I molar relationship is achieved within 2-6 months. Hundreds of cases have been treated with these appliances over a number of years at Queen's Hospital, Burton upon Trent with great success.

  20. Enhanced presentation of MHC class Ia, Ib and class II-restricted peptides encapsulated in biodegradable nanoparticles: a promising strategy for tumor immunotherapy.

    PubMed

    Ma, Wenxue; Smith, Trevor; Bogin, Vladimir; Zhang, Yu; Ozkan, Cengiz; Ozkan, Mihri; Hayden, Melanie; Schroter, Stephanie; Carrier, Ewa; Messmer, Davorka; Kumar, Vipin; Minev, Boris

    2011-03-31

    Many peptide-based cancer vaccines have been tested in clinical trials with a limited success, mostly due to difficulties associated with peptide stability and delivery, resulting in inefficient antigen presentation. Therefore, the development of suitable and efficient vaccine carrier systems remains a major challenge. To address this issue, we have engineered polylactic-co-glycolic acid (PLGA) nanoparticles incorporating: (i) two MHC class I-restricted clinically-relevant peptides, (ii) a MHC class II-binding peptide, and (iii) a non-classical MHC class I-binding peptide. We formulated the nanoparticles utilizing a double emulsion-solvent evaporation technique and characterized their surface morphology, size, zeta potential and peptide content. We also loaded human and murine dendritic cells (DC) with the peptide-containing nanoparticles and determined their ability to present the encapsulated peptide antigens and to induce tumor-specific cytotoxic T lymphocytes (CTL) in vitro. We confirmed that the nanoparticles are not toxic to either mouse or human dendritic cells, and do not have any effect on the DC maturation. We also demonstrated a significantly enhanced presentation of the encapsulated peptides upon internalization of the nanoparticles by DC, and confirmed that the improved peptide presentation is actually associated with more efficient generation of peptide-specific CTL and T helper cell responses. Encapsulating antigens in PLGA nanoparticles offers unique advantages such as higher efficiency of antigen loading, prolonged presentation of the antigens, prevention of peptide degradation, specific targeting of antigens to antigen presenting cells, improved shelf life of the antigens, and easy scale up for pharmaceutical production. Therefore, these findings are highly significant to the development of synthetic vaccines, and the induction of CTL for adoptive immunotherapy.

  1. Role of metalloproteases in vaccinia virus epitope processing for transporter associated with antigen processing (TAP)-independent human leukocyte antigen (HLA)-B7 class I antigen presentation.

    PubMed

    Lorente, Elena; García, Ruth; Mir, Carmen; Barriga, Alejandro; Lemonnier, François A; Ramos, Manuel; López, Daniel

    2012-03-23

    The transporter associated with antigen processing (TAP) translocates the viral proteolytic peptides generated by the proteasome and other proteases in the cytosol to the endoplasmic reticulum lumen. There, they complex with nascent human leukocyte antigen (HLA) class I molecules, which are subsequently recognized by the CD8(+) lymphocyte cellular response. However, individuals with nonfunctional TAP complexes or tumor or infected cells with blocked TAP molecules are able to present HLA class I ligands generated by TAP-independent processing pathways. Herein, using a TAP-independent polyclonal vaccinia virus-polyspecific CD8(+) T cell line, two conserved vaccinia-derived TAP-independent HLA-B*0702 epitopes were identified. The presentation of these epitopes in normal cells occurs via complex antigen-processing pathways involving the proteasome and/or different subsets of metalloproteinases (amino-, carboxy-, and endoproteases), which were blocked in infected cells with specific chemical inhibitors. These data support the hypothesis that the abundant cellular proteolytic systems contribute to the supply of peptides recognized by the antiviral cellular immune response, thereby facilitating immunosurveillance. These data may explain why TAP-deficient individuals live normal life spans without any increased susceptibility to viral infections.

  2. Role of Metalloproteases in Vaccinia Virus Epitope Processing for Transporter Associated with Antigen Processing (TAP)-independent Human Leukocyte Antigen (HLA)-B7 Class I Antigen Presentation*

    PubMed Central

    Lorente, Elena; García, Ruth; Mir, Carmen; Barriga, Alejandro; Lemonnier, François A.; Ramos, Manuel; López, Daniel

    2012-01-01

    The transporter associated with antigen processing (TAP) translocates the viral proteolytic peptides generated by the proteasome and other proteases in the cytosol to the endoplasmic reticulum lumen. There, they complex with nascent human leukocyte antigen (HLA) class I molecules, which are subsequently recognized by the CD8+ lymphocyte cellular response. However, individuals with nonfunctional TAP complexes or tumor or infected cells with blocked TAP molecules are able to present HLA class I ligands generated by TAP-independent processing pathways. Herein, using a TAP-independent polyclonal vaccinia virus-polyspecific CD8+ T cell line, two conserved vaccinia-derived TAP-independent HLA-B*0702 epitopes were identified. The presentation of these epitopes in normal cells occurs via complex antigen-processing pathways involving the proteasome and/or different subsets of metalloproteinases (amino-, carboxy-, and endoproteases), which were blocked in infected cells with specific chemical inhibitors. These data support the hypothesis that the abundant cellular proteolytic systems contribute to the supply of peptides recognized by the antiviral cellular immune response, thereby facilitating immunosurveillance. These data may explain why TAP-deficient individuals live normal life spans without any increased susceptibility to viral infections. PMID:22298786

  3. Loss of antigen-presenting molecules (MHC class I and TAP-1) in lung cancer.

    PubMed Central

    Korkolopoulou, P.; Kaklamanis, L.; Pezzella, F.; Harris, A. L.; Gatter, K. C.

    1996-01-01

    Presentation of endogenous antigenic peptides to cytotoxic T lymphocytes is mediated by the major histocompatibility complex (MHC) class I molecules. For the stable assembly of MHC class I complex it is necessary that the antigenic peptide is transported by the MHC-encoded transporters TAP-1 and TAP-2 into a pre-Golgi region. T-cell-mediated host-vs-tumour response might therefore depend on the presence of these molecules on tumour cells. The presence of MHC class I antigens and TAP-1 was studied in a series of 93 resection specimens of non-small-cell lung carcinomas (NSCLCs) by immunohistochemical methods using antibodies against the assembled class I molecule, beta 2-microglobulin (beta 2-m), heavy-chain A locus, A2 allele and TAP-1 protein. Eighty-six patients were included in the survival analysis. Total loss of class I molecule was observed in 38% of the cases and was usually accompanied by loss of beta 2-m and of heavy chain A locus. Selective loss of A locus was seen in 8.3% and of A2 allele in 27% of the cases. TAP-1 loss was always combined with beta 2-m and/or heavy chain A locus loss. No correlation was found between the expressional status of any of the above molecules, including the selective A2 allelic loss and histological type, degree of differentiation, tumoral stage, nodal stage and survival. Our findings suggest that loss of antigen-presenting molecules (including both MHC class I alleles and TAP-1) is a frequent event in lung cancer. However, the immunophenotypic profile of MHC class I and TAP-1 seems to be unrelated in vivo to the phenotype, growth or survival of NSCLC. Images Figure 1 PMID:8546899

  4. Evolution and Distribution of Class II-Related Endogenous Retroviruses†

    PubMed Central

    Gifford, Robert; Kabat, Peter; Martin, Joanne; Lynch, Clare; Tristem, Michael

    2005-01-01

    Endogenous retroviruses (ERVs) are widespread in vertebrate genomes and have been loosely grouped into “classes” on the basis of their phylogenetic relatedness to the established genera of exogenous retroviruses. Four of these genera—the lentiviruses, alpharetroviruses, betaretroviruses, and deltaretroviruses—form a well-supported clade in retroviral phylogenies, and ERVs that group with these genera have been termed class II ERVs. We used PCR amplification and sequencing of retroviral fragments from more than 130 vertebrate taxa to investigate the evolution of the class II retroviruses in detail. We confirm that class II retroviruses are largely confined to mammalian and avian hosts and provide evidence for a major novel group of avian retroviruses, and we identify additional members of both the alpha- and the betaretrovirus genera. Phylogenetic analyses demonstrated that the avian and mammalian viruses form distinct monophyletic groups, implying that interclass transmission has occurred only rarely during the evolution of the class II retroviruses. In contrast to previous reports, the lentiviruses clustered as sister taxa to several endogenous retroviruses derived from rodents and insectivores. This topology was further supported by the shared loss of both the class II PR-Pol frameshift site and the class II retrovirus G-patch domain. PMID:15858031

  5. [Planar molecular arrangements aid the design of MHC class II binding peptides].

    PubMed

    Cortés, A; Coral, J; McLachlan, C; Benítez, R; Pinilla, L

    2017-01-01

    The coupling between peptides and MHC-II proteins in the human immune system is not well understood. This work presents an evidence-based hypothesis of a guiding intermolecular force present in every human MHC-II protein (HLA-II). Previously, we examined the spatial positions of the fully conserved residues in all HLA-II protein types. In each one, constant planar patterns were revealed. These molecular planes comprise of amino acid groups of the same chemical species (for example, Gly) distributed across the protein structure. Each amino acid plane has a unique direction and this directional element offers spatial selectivity. Constant within all planes, too, is the presence of an aromatic residue possessing electrons in movement, leading the authors to consider that the planes generate electromagnetic fields that could serve as an attractive force in a single direction. Selection and attraction between HLA-II molecules and antigen peptides would, therefore, be non-random, resulting in a coupling mechanism as effective and rapid as is clearly required in the immune response. On the basis of planar projections onto the HLA-II groove, modifications were made by substituting the key residues in the class II-associated invariant chain peptide-a peptide with a universal binding affinity-resulting in eight different modified peptides with affinities greater than that of the unmodified peptide. Accurate and reliable prediction of MHC class II-binding peptides may facilitate the design of universal vaccine-peptides with greatly enhanced binding affinities. The proposed mechanisms of selection, attraction and coupling between HLA-II and antigen peptides are explained further in the paper.

  6. Mandibular growth comparisons of Class I and Class II division 1 skeletofacial patterns.

    PubMed

    Jacob, Helder B; Buschang, Peter H

    2014-09-01

    To determine class and sex differences in mandibular growth and modeling. A mixed-longitudinal sample of 130 untreated French-Canadian adolescents, 77 (45 boys and 32 girls) with Class I (normal or abnormal) occlusion and 53 (26 boys and 27 girls) with Class II division 1 malocclusion, was used. Based on eight landmarks, eight traditional measurements were used to compare the anteroposterior position of the maxilla and mandible, relationship between the jaws, and mandibular size. Mandibular superimpositions were used to compare the horizontal and vertical changes of condylion, gonion, and menton. While there were no differences in maxillary position based on the SNA angle, Class IIs had more retrognathic mandibles than did Class Is. Total mandibular length was greater in Class Is than in Class IIs at 15 years of age. Superior and total growth and modeling changes at condylion and gonion, respectively, were greater for Class Is than Class IIs. Boys were more prognathic than girls; they had larger mandibles and exhibited greater size increases and growth changes than girls did. There are both class and sex differences in mandibular growth and modeling.

  7. 18 CFR 415.21 - Class II projects.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Class II projects. 415.21 Section 415.21 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... part, include all projects other than Class I projects, in non-tidal areas of the basin, which involve...

  8. 18 CFR 415.21 - Class II projects.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Class II projects. 415.21 Section 415.21 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... part, include all projects other than Class I projects, in non-tidal areas of the basin, which involve...

  9. 18 CFR 415.21 - Class II projects.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Class II projects. 415.21 Section 415.21 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... part, include all projects other than Class I projects, in non-tidal areas of the basin, which involve...

  10. 18 CFR 415.21 - Class II projects.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Class II projects. 415.21 Section 415.21 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... part, include all projects other than Class I projects, in non-tidal areas of the basin, which involve...

  11. 18 CFR 415.21 - Class II projects.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Class II projects. 415.21 Section 415.21 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... part, include all projects other than Class I projects, in non-tidal areas of the basin, which involve...

  12. Efficient major histocompatibility complex class I presentation of exogenous antigen upon phagocytosis by macrophages.

    PubMed Central

    Kovacsovics-Bankowski, M; Clark, K; Benacerraf, B; Rock, K L

    1993-01-01

    Antigens in extracellular fluids can be processed and presented with major histocompatibility complex (MHC) class I molecules by a subset of antigen presenting cells (APCs). Chicken egg ovalbumin (Ova) linked to beads was presented with MHC class I molecules by these cells up to 10(4)-fold more efficiently than soluble Ova. This enhanced presentation was observed with covalently or noncovalently linked Ova and with beads of different compositions. A key parameter in the activity of these conjugates was the size of the beads. The APC that is responsible for this form of presentation is a macrophage. These cells internalize the antigen constructs through phagocytosis, since cytochalasin B inhibited presentation. Processing of the antigen and association with MHC class I molecules appears to occur intracellularly as presentation was observed under conditions where there was no detectable release of peptides into the extracellular fluids. When injected in vivo in C57BL/6 mice, Ova-beads, but not soluble Ova, primed CD4- CD8+ cytotoxic T lymphocytes (CTLs). Similar results were obtained in BALB/c mice immunized with beta-galactosidase-beads. The implications of these findings for development of nonliving vaccines that stimulate CTL immunity are discussed. PMID:8506338

  13. Evolution of the major histocompatibility complex: isolation of class II A cDNA clones from the cartilaginous fish.

    PubMed Central

    Kasahara, M; Vazquez, M; Sato, K; McKinney, E C; Flajnik, M F

    1992-01-01

    Along with the T-cell receptor and immunoglobulin, the major histocompatibility complex (MHC) plays a key role in mounting immune responses to foreign antigen. To gain insights into the evolution of the MHC, class II A cDNA clones were isolated from nurse sharks, a member of the class of cartilaginous fish. Two closely related cDNA clones, which might encode allelic products, were identified; of the three amino acid substitutions found in the alpha 1 domain, two were located at positions postulated to interact with processed peptides. The deduced nurse shark MHC class II alpha chains showed conspicuous structural similarity to their mammalian counterparts. Isolation of cDNA clones encoding typical MHC class II alpha chains was unexpected since no direct evidence for T-cell-mediated immune responses has been obtained in the cartilaginous fish. The cartilaginous fish is phylogenetically the most primitive class of vertebrates from which any MHC gene has been isolated. PMID:1495958

  14. Blocking MHC class II on human endothelium mitigates acute rejection

    PubMed Central

    Abrahimi, Parwiz; Qin, Lingfeng; Chang, William G.; Bothwell, Alfred L.M.; Tellides, George; Saltzman, W. Mark; Pober, Jordan S.

    2016-01-01

    Acute allograft rejection is mediated by host CD8+ cytotoxic T lymphocytes (CTL) targeting graft class I major histocompatibility complex (MHC) molecules. In experimental rodent models, rejection requires differentiation of naive CD8+ T cells into alloreactive CTL within secondary lymphoid organs, whereas in humans, CTL may alternatively develop within the graft from circulating CD8+ effector memory T cells (TEM) that recognize class I MHC molecules on graft endothelial cells (EC). This latter pathway is poorly understood. Here, we show that host CD4+ TEM, activated by EC class II MHC molecules, provide critical help for this process. First, blocking HLA-DR on EC lining human artery grafts in immunodeficient mice reduces CD8+ CTL development within and acute rejection of the artery by adoptively transferred allogeneic human lymphocytes. Second, siRNA knockdown or CRISPR/Cas9 ablation of class II MHC molecules on EC prevents CD4+ TEM from helping CD8+ TEM to develop into CTL in vitro. Finally, implanted synthetic microvessels, formed from CRISPR/Cas9-modified EC lacking class II MHC molecules, are significantly protected from CD8+ T cell–mediated destruction in vivo. We conclude that human CD8+ TEM–mediated rejection targeting graft EC class I MHC molecules requires help from CD4+ TEM cells activated by recognition of class II MHC molecules. PMID:26900601

  15. A retrospective study of Class II mixed-dentition treatment.

    PubMed

    Oh, Heesoo; Baumrind, Sheldon; Korn, Edward L; Dugoni, Steven; Boero, Roger; Aubert, Maryse; Boyd, Robert

    2017-01-01

    To consider the effectiveness of early treatment using one mixed-dentition approach to the correction of moderate and severe Class II malocclusions. Three groups of Class II subjects were included in this retrospective study: an early treatment (EarlyTx) group that first presented at age 7 to 9.5 years (n = 54), a late treatment (LateTx) group whose first orthodontic visit occurred between ages 12 and 15 (n = 58), and an untreated Class II (UnTx) group to assess the pretreatment comparability of the two treated groups (n = 51). Thirteen conventional cephalometric measurements were reported for each group and Class II molar severity was measured on the study casts of the EarlyTx and LateTx groups. Successful Class II correction was observed in approximately three quarters of both the EarlyTx group and the LateTx group at the end of treatment. EarlyTx patients had fewer permanent teeth extracted than did the LateTx patients (5.6% vs 37.9%, P < .001) and spent less time in full-bonded appliance therapy in the permanent dentition than did LateTx patients (1.7 ± 0.8 vs 2.6 ± 0.7years, P < .001). When supervision time is included, the EarlyTx group had longer total treatment time and averaged more visits than did the LateTx group (53.1 ± 18. 8 vs 33.7 ± 8.3, P < .0001). Fifty-five percent of the LateTx extraction cases involved removal of the maxillary first premolars only and were finished in a Class II molar relationship. EarlyTx comprehensive mixed-dentition treatment was an effective modality for early correction of Class II malocclusions.

  16. BoLA class I polymorphism and in vitro immune response to M. bovis antigens.

    PubMed

    Longeri, M; Polli, M; Ponti, W; Zanotti, M

    1993-01-12

    From a sample of 119 Friesian calves, serologically typed for BoLA class I, 47 subjects were chosen expressing 9 different MHC types (A6, A6.9, A10, A11, A14, A15, A30, W16, M103) with the same age and reared in the same farm conditions. The animals were s.c. injected with a water in oil suspension of killed M. bovis and the treatment was repeated two days later. Before the treatment and 21 days later, calves were bled and on PBM (peripheral blood mononuclear leucocytes) were performed the following tests: 1. Lymphocyte Stimulation with bovine and avian PPDs (Purified protein derivative of Mycobacterium bovis and Mycobacterium avium, respectively). 2. Phagocytic activity towards M. bovis. 3. Class II molecules expression on cell surface. 4. Percentage of leucocyte populations and subpopulations. In the in vitro Lymphocyte Stimulation test, all the animals and classes were responders. Animals bearing A10 BoLA class I presented c.p.m. (counts per minute) and index values higher than the other cattle; these values were significantly positively related both to bovine and avian PPDs (P < .01). By variance analysis A14 BoLA type showed a slight positive significant correlation with more efficient phagocytic activity. BoLA class I type did not seem to significantly affect percentage of class II positive cells and leucocyte percentages on PBM. ZUSAMMENFASSUNG: Der BoLA Klasse I Polymorphismus und in vitro immunologische Antwort gegen die Antigene von M. bovis Aus einer Stichprobe von 119 für BoLA Klasse I serologisch typisierten Friesian Kälber, wurden 47 Subjekte ausgewählt, die 9 verschiedene MHC Typen ausdrückten (A6, A6.9, A10, A11, A14, A15, A30, W16, M103). Alle waren gleich alt und in gleichen Haltungsbedingungen. Die Tiere wurden mit einer Wasser-in-Ol Suspension abgetöteter M. bovis subkutan injiziert und die Behandlung nach zwei Tagen wiederholt. Vor und 21 Tage nach Behandlung wurden die folgenden Tests ausgeführt: 1. Lymphozyten-Stimulationstest mit

  17. Minimal conformational plasticity enables TCR cross-reactivity to different MHC class II heterodimers

    PubMed Central

    Holland, Christopher J.; Rizkallah, Pierre J.; Vollers, Sabrina; Calvo-Calle, J. Mauricio; Madura, Florian; Fuller, Anna; Sewell, Andrew K.; Stern, Lawrence J.; Godkin, Andrew; Cole, David K.

    2012-01-01

    Successful immunity requires that a limited pool of αβ T-cell receptors (TCRs) provide cover for a vast number of potential foreign peptide antigens presented by ‘self’ major histocompatibility complex (pMHC) molecules. Structures of unligated and ligated MHC class-I-restricted TCRs with different ligands, supplemented with biophysical analyses, have revealed a number of important mechanisms that govern TCR mediated antigen recognition. HA1.7 TCR binding to the influenza hemagglutinin antigen (HA306–318) presented by HLA-DR1 or HLA-DR4 represents an ideal system for interrogating pMHC-II antigen recognition. Accordingly, we solved the structure of the unligated HA1.7 TCR and compared it to both complex structures. Despite a relatively rigid binding mode, HA1.7 T-cells could tolerate mutations in key contact residues within the peptide epitope. Thermodynamic analysis revealed that limited plasticity and extreme favorable entropy underpinned the ability of the HA1.7 T-cell clone to cross-react with HA306–318 presented by multiple MHC-II alleles. PMID:22953050

  18. The impact of DM on MHC class II–restricted antigen presentation can be altered by manipulation of MHC–peptide kinetic stability

    PubMed Central

    Lazarski, Christopher A.; Chaves, Francisco A.; Sant, Andrea J.

    2006-01-01

    DM edits the peptide repertoire presented by major histocompatibility complex class II molecules by professional antigen-presenting cells (APCs), favoring presentation of some peptides over others. Despite considerable research by many laboratories, there is still significant uncertainty regarding the biochemical attributes of class II–peptide complexes that govern their susceptibility to DM editing. Here, using APCs that either do or do not express DM and a set of unrelated antigens, we found that the intrinsic kinetic stability of class II–peptide complexes is tightly correlated with the effects of DM editing within APCs. Furthermore, through the use of kinetic stability variants of three independent peptides, we demonstrate that increasing or decreasing the kinetic stability of class II–peptide complexes causes a corresponding alteration in DM editing. Finally, we show that the spontaneous kinetic stability of class II complexes correlates directly with the efficiency of presentation by DM+ APCs and the immunodominance of that class II–peptide complex during an immune response. Collectively, these results suggest that the pattern of DM editing in APCs can be intentionally changed by modifying class II–peptide interactions, leading to the desired hierarchy of presentation on APCs, thereby promoting recruitment of CD4 T cells specific for the preferred peptides during an immune response. PMID:16682499

  19. Retention of empty MHC class I molecules by tapasin is essential to reconstitute antigen presentation in invertebrate cells.

    PubMed Central

    Schoenhals, G J; Krishna, R M; Grandea, A G; Spies, T; Peterson, P A; Yang, Y; Früh, K

    1999-01-01

    Presentation of antigen-derived peptides by major histocompatibility complex (MHC) class I molecules is dependent on an endoplasmic reticulum (ER) resident glycoprotein, tapasin, which mediates their interaction with the transporter associated with antigen processing (TAP). Independently of TAP, tapasin was required for the presentation of peptides targeted to the ER by signal sequences in MHC class I-transfected insect cells. Tapasin increased MHC class I peptide loading by retaining empty but not peptide-containing MHC class I molecules in the ER. Upon co-expression of TAP, this retention/release function of tapasin was sufficient to reconstitute MHC class I antigen presentation in insect cells, thus defining the minimal non-housekeeping functions required for MHC class I antigen presentation. PMID:9927434

  20. Determinants of the DNA binding specificity of class I and class II TCP transcription factors.

    PubMed

    Viola, Ivana L; Reinheimer, Renata; Ripoll, Rodrigo; Manassero, Nora G Uberti; Gonzalez, Daniel H

    2012-01-02

    TCP proteins constitute a family of plant transcription factors with more than 20 members in angiosperms. They can be divided in two classes based on sequence homology and the presence of an insertion within the basic region of the TCP DNA binding and dimerization domain. Here, we describe binding site selection studies with the class I protein TCP16, showing that its DNA binding preferences are similar to those of class II proteins. Through sequence comparison and the analysis of mutants and chimeras of TCP16, TCP20 (class I), and TCP4 (class II), we established that the identity of residue 11 of the class I TCP domain or the equivalent residue 15 of the class II domain, whether it is Gly or Asp, determines a preference for a class I or a class II sequence, respectively. Footprinting analysis indicated that specific DNA contacts related to these preferences are established with one of the strands of DNA. The dimerization motif also influences the selectivity of the proteins toward class I and class II sequences and determines a requirement of an extended basic region in proteins with Asp-15. We postulate that differences in orientation of base-contacting residues brought about by the presence of either Gly or Asp are responsible for the binding site preferences of TCP proteins. Expression of repressor forms of TCP16 with Asp-11 or Gly-11 differently affects leaf development. TCP16-like proteins with Asp-11 in the TCP domain arose in rosids and may be related to developmental characteristics of this lineage of eudicots.

  1. 40 CFR 144.19 - Transitioning from Class II to Class VI.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Transitioning from Class II to Class VI. 144.19 Section 144.19 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER...) Increase in carbon dioxide injection rates; (3) Decrease in reservoir production rates; (4) Distance...

  2. Changes in Cranial Base Morphology in Class I and Class II Division 1 Malocclusions.

    PubMed

    Agarwal, Anirudh; Pandey, Harsh; Bajaj, Kamal; Pandey, Lavesh

    2013-02-01

    The cranial base plays a key role in craniofacial growth; it helps to integrate spatially and functionally different patterns of growth in various adjoining regions of the skull such as components of the brain, the nasal and oral cavity and the pharynx. The aim of this study was to evaluate the difference in cranial base flexure between skeletal and dental Class I and Class II division 1. Lateral cephalometric radiograph, of Class I and Class II with an average growth pattern were analyzed and compared. A total of 103 patients having class I (n=52) and class II (n=51) malocclusion, were taken from Department of Orthodontics, Rajasthan Dental College & Hospital, Jaipur. Cranial base angle (N-S-Ar) and ANB were measured on pre treatment lateral cephalograms. In this study cranial base angle did not show statistically significant difference between the two groups studied. In the assessment of orthodontic problems involving anteroposterior malrelationships of the jaws, the problem is usually the result of size, form and position of the jaw. The present study failed to find any differences in cranial base angle between sagittal malocclusions. How to cite this article: Agarwal A, Pandey H, Bajaj K, Pandey L. Changes in Cranial Base Morphology in Class I and Class II Division 1 Malocclusion. J Int Oral Health 2013; 5(1):39-42.

  3. Induction of antigen-specific class I-restricted cytotoxic T cells by soluble proteins in vivo.

    PubMed Central

    Raychaudhuri, S; Tonks, M; Carbone, F; Ryskamp, T; Morrow, W J; Hanna, N

    1992-01-01

    Cytotoxic T lymphocytes (CTL) are induced specifically against viral and tumor antigens presented by major histocompatibility complex class I molecules on the surface of infected or transformed cells. Intracellular synthesized antigens are processed and associated with class I antigens within cells before presentation on the cell surface. Because of this special requirement for CTL induction, exogenous soluble antigens do not, in general, induce specific CTL responses. To overcome this problem, various laboratories have resorted to the use of vaccinia virus and other replicating expression vectors for intracellular antigen delivery leading to the stimulation of humoral and cell-mediated immunity to specific proteins. However, for human use it is safer to use purified and defined antigens for inducing immune responses. Using soluble ovalbumin and human immunodeficiency virus glycoprotein gp120, we have explored the possibility of using an antigen formulation consisting of squalane and Tween 80 to elicit antigen-specific CTL responses in mice. We have demonstrated that this antigen formulation is a potent inducer of CD8+, class I-restricted, antigen-specific CTLs. The CTL priming induced by soluble antigen in squalane/Tween 80 resembles the reported response to the vaccinia recombinant containing human immunodeficiency virus envelope protein and by splenocytes cytoplasmically loaded with soluble ovalbumin. The ramifications of these findings for vaccine development are discussed. PMID:1518862

  4. Induction of antigen-specific class I-restricted cytotoxic T cells by soluble proteins in vivo.

    PubMed

    Raychaudhuri, S; Tonks, M; Carbone, F; Ryskamp, T; Morrow, W J; Hanna, N

    1992-09-01

    Cytotoxic T lymphocytes (CTL) are induced specifically against viral and tumor antigens presented by major histocompatibility complex class I molecules on the surface of infected or transformed cells. Intracellular synthesized antigens are processed and associated with class I antigens within cells before presentation on the cell surface. Because of this special requirement for CTL induction, exogenous soluble antigens do not, in general, induce specific CTL responses. To overcome this problem, various laboratories have resorted to the use of vaccinia virus and other replicating expression vectors for intracellular antigen delivery leading to the stimulation of humoral and cell-mediated immunity to specific proteins. However, for human use it is safer to use purified and defined antigens for inducing immune responses. Using soluble ovalbumin and human immunodeficiency virus glycoprotein gp120, we have explored the possibility of using an antigen formulation consisting of squalane and Tween 80 to elicit antigen-specific CTL responses in mice. We have demonstrated that this antigen formulation is a potent inducer of CD8+, class I-restricted, antigen-specific CTLs. The CTL priming induced by soluble antigen in squalane/Tween 80 resembles the reported response to the vaccinia recombinant containing human immunodeficiency virus envelope protein and by splenocytes cytoplasmically loaded with soluble ovalbumin. The ramifications of these findings for vaccine development are discussed.

  5. Characterisation of four major histocompatibility complex class II genes of the koala (Phascolarctos cinereus).

    PubMed

    Lau, Quintin; Jobbins, Sarah E; Belov, Katherine; Higgins, Damien P

    2013-01-01

    Major histocompatibility complex (MHC) class II molecules have an integral role in the adaptive immune response, as they bind and present antigenic peptides to T helper lymphocytes. In this study of koalas, species-specific primers were designed to amplify exon 2 of the MHC class II DA and DB genes, which contain much of the peptide-binding regions of the α and β chains. A total of two DA α1 domain variants and eight DA β1 (DAB), three DB α1 and five DB β1 variants were amplified from 20 koalas from two free-living populations from South East Queensland and the Port Macquarie region in northern New South Wales. We detected greater variation in the β1 than in the α1 domains as well as evidence of positive selection in DAB. The present study provides a springboard to future investigation of the role of MHC in disease susceptibility in koalas.

  6. Type II and III Receptors for Immunoglobulin G (IgG) Control the Presentation of Different T Cell Epitopes from Single IgG-complexed Antigens

    PubMed Central

    Amigorena, Sebastian; Lankar, Danielle; Briken, Volker; Gapin, Laurent; Viguier, Mireille; Bonnerot, Christian

    1998-01-01

    T cell receptors on CD4+ lymphocytes recognize antigen-derived peptides presented by major histocompatibility complex (MHC) class II molecules. A very limited set of peptides among those that may potentially bind MHC class II is actually presented to T lymphocytes. We here examine the role of two receptors mediating antigen internalization by antigen presenting cells, type IIb2 and type III receptors for IgG (FcγRIIb2 and FcγRIII, respectively), in the selection of peptides for presentation to T lymphocytes. B lymphoma cells expressing recombinant FcγRIIb2 or FcγRIII were used to assess the presentation of several epitopes from two different antigens. 4 out of the 11 epitopes tested were efficiently presented after antigen internalization through FcγRIIb2 and FcγRIII. In contrast, the 7 other epitopes were efficiently presented only when antigens were internalized through FcγRIII, but not through FcγRIIb2. The capacity to present these latter epitopes was transferred to a tail-less FcγRIIb2 by addition of the FcγRIII-associated γ chain cytoplasmic tail. Mutation of a single leucine residue at position 35 of the γ chain cytoplasmic tail resulted in the selective loss of presentation of these epitopes. Therefore, the nature of the receptor that mediates internalization determines the selection of epitopes presented to T lymphocytes within single protein antigens. PMID:9463401

  7. In Situ Peptide-MHC-II Tetramer Staining of Antigen-Specific CD4+ T Cells in Tissues

    PubMed Central

    Cleary, P. Patrick; Skinner, Pamela J.

    2015-01-01

    The invention of peptide-MHC-tetramer technology to label antigen-specific T cells has led to an enhanced understanding of T lymphocyte biology. Here we describe the development of an in situ pMHC-II tetramer staining method to visualize antigen-specific CD4+ T cells in tissues. This method complements other methods developed that similarly use MHC class II reagents to stain antigen-specific CD4+ T cells in situ. In this study, we used group A streptococcus (GAS) expressing a surrogate peptide (2W) to inoculate C57BL/6 mice, and used fresh nasal-associated lymphoid tissues (NALT) in optimizing the in situ staining of 2W:I-Ab specific CD4+ T cells. The results showed 2W:I-Ab tetramer-binding CD4+ T cells in GAS-2W but not GAS infected mice. This method holds promise to be broadly applicable to study the localization, abundance, and phenotype of antigen-specific CD4+ T cells in undisrupted tissues. PMID:26067103

  8. [Analysis of soft tissue thickness in persons with malocclusions of Class II division 1 and Class II division 2].

    PubMed

    Tanić, Tatjana; Blažej, Zorica; Mitić, Vladimir

    2012-01-01

    Different malocclusions indicate different thickness of facial soft tissue. The aim of the study was to establish the differences in the thickness of facial soft tissue profile in persons with dentoskeletal Class II/1 and II/2 relationship. In the study we used cephalometric rendgenograms profile analysis of 60 patients aged 12-18 years of the Dental Clinic in Nis who had not previously undergone orthodontical treatment. According to the dentoskeletal jaws relations the patients were divided into two groups with Class II division 1 and Class II class division 2. In all of them the standard dentoskeletal profile analysis by Steiner and soft tissue profile analysis by Burston was done. The obtained findings were statistically analyzed and the comparison between the studied groups was performed. The results indicated the following: in the patients with Class II/1 relationship there was a significantly thinner upper lip (t=5.741; p<0.0001), thinner upper lip sulcus (t=3.858; p<0.001) and significantly thinner lower lip (t=2.009; p<0.05) in relation to the patients with Class 11/2. Compensatory effect in the Class II/1 patients was more distinctive in females, as their soft tissue profiles were thicker. In Class 11/2 patients this relationship was in favor of males. The facial soft tissue profile indicated significant differences in the thickness dependant on the type of malocclusion and gender. Because of their great variability and a significant participation in the formation of the profile, while planning orthodontic therapy, it is necessary to pay them full attention, with obligatory analysis of the dentoskeletal profile.

  9. A study on human leukocyte antigen class I molecules in paediatric bronchial asthma.

    PubMed

    Mishra, Mahendra N; Dudeja, Puja; Gupta, Rakesh K

    2014-04-01

    Childhood asthma, often associated with atopy, is more common in boys and may persist throughout life in 50% of cases. This case-control study was carried out to examine if any association of paediatric bronchial asthma with human leukocyte antigen (HLA) class I antigens. Thirty-six children with bronchial asthma diagnosed on basis of Global Initiative for Asthma (GINA) criteria and an equal number of healthy controls without history of bronchial asthma were studied. Low resolution HLA- ABC typing was performed by sequence specific primers (SSP) and the frequency of HLA-ABC antigens in the two groups was compared. Total serum immunoglobulin E (IgE) estimation was done as a marker of atopy by ELISA. The study included 24 boys and 12 girls aged 13 months to 11 yrs, of which 16 (44%) had positive family history. Serum IgE levels were elevated in 20 (55%) of the cases and 33% of controls with peak values of 4877 and 627 IU/ml, respectively. No statistically significant correlation was observed between childhood asthma and HLA class I antigens, however, a statistically significant correlation was observed between serum IgE levels and asthma, which was elevated in cases, as compared to normal population. Serum IgE levels did not show a linear trend, in that a direct correlation with the severity of disease was not observed.

  10. [MHC class I antigens, CD4 and CD8 expressions in polymyositis and dermatomyositis].

    PubMed

    Graça, Carla Renata; Kouyoumdjian, João Aris

    2015-01-01

    To analyze the frequencies of the expression of major histocompatibility complex class I (MHC-I) antigens, and CD4 and CD8 cells in skeletal muscle in polymyositis (PM) and dermatomyositis (DM). This was a retrospective study of 34 PM cases, 8 DM cases, and 29 control patients with non-inflammatory myopathies. MHC-I antigens were expressed in the sarcolemma and/or sarcoplasm in 79.4% of PM cases, 62.5% of DM cases, and 27.6% of controls (CD4 expression was observed in 76.5%, 75%, and 13.8%, respectively). There was a high suspicion of PM/DM (mainly PM) in patients in whom MHC-I antigens and CD4 were co-expressed. In 14.3% of PM/DM cases, we observed MHC-I antigens expression alone, without inflammatory cells. MCH-I antigens expression and CD4 positivity might add to strong diagnostic suspicion of PM/DM. No cellular infiltration was observed in 14.3% of such cases. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

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

    PubMed

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

    2006-08-01

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

  12. Measles virus transmembrane fusion protein synthesized de novo or presented in immunostimulating complexes is endogenously processed for HLA class I- and class II-restricted cytotoxic T cell recognition

    PubMed Central

    1992-01-01

    The routes used by antigen-presenting cells (APC) to convert the transmembrane fusion glycoprotein (F) of measles virus (MV) to HLA class I and class II presentable peptides have been examined, using cloned cytotoxic T lymphocytes in functional assays. Presentation by Epstein-Barr virus-transformed B lymphoblastoid cell lines was achieved using live virus, ultraviolet light-inactivated virus, and purified MV- F delivered either as such or incorporated in immunostimulating complexes (MV-F-ISCOM). Only live virus and MV-F-ISCOM allow presentation by class I molecules, while all antigen preparations permit class II-restricted presentation. We observe presentation of MV- F from live virus and as MV-F-ISCOM by class II molecules in a fashion that is not perturbed by chloroquine. Our studies visualize novel presentation pathways of type I transmembrane proteins. PMID:1613454

  13. Airway in Class I and Class II skeletal pattern: A computed tomography study

    PubMed Central

    Paul, Deepthi; Varma, Sapna; Ajith, V. V.

    2015-01-01

    Background and Objectives: A normal airway is required for the normal growth of the craniofacial structures. The present study was designed to evaluate and compare the airway in Class I and Class II skeletal pattern and to see if there is any association between the airway and maxillomandibular relationship. Materials and Methods: Peripheral nervous system computed tomography scans of 30 patients were divided into two groups as Class I (ANB ≤ 4.5°), Class II (ANB ≥ 4.5°). The Dolphin three-dimensional version 11 was used to assess the airway. Statistical Analysis: Correlations between the variables were tested with the Pearson correlation coefficient. Independent sample t-test was performed to compare the averages between the two groups. P < 0.05 was considered as statistically significant. Results: The ANB angle was negatively correlated with all the airway parameters. The airway area and volume was significantly reduced in Class II subjects compared to Class I. Conclusion: The results suggest a strong association between the airway and skeletal pattern showing a reduced airway in Class II patients with a high ANB angle. PMID:26321823

  14. Immunological and clinical significance of HLA class I antigen processing machinery component defects in malignant cells

    PubMed Central

    Concha-Benavente, Fernando; Srivastava, Raghvendra; Ferrone, Soldano; Ferris, Robert L.

    2017-01-01

    Experimental as well as clinical studies demonstrate that the immune system plays a major role in controlling generation and progression of tumors. The cancer immunoediting theory supports the notion that tumor cell immunogenicity is dynamically shaped by the immune system, as it eliminates immunogenic tumor cells in the early stage of the disease and then edits their antigenicity. The end result is the generation of a tumor cell population able to escape from immune recognition and elimination by tumor infiltrating lymphocytes. Two major mechanisms, which affect the target cells and the effector phase of the immune response, play a crucial role in the editing process. One is represented by the downregulation of tumor antigen (TA) processing and presentation because of abnormalities in the HLA class I antigen processing machinery (APM). The other one is represented by the anergy of effector immune infiltrates in the tumor microenvironment caused by aberrant inhibitory signals triggered by immune checkpoint receptor (ICR) ligands, such as programmed death ligand-1 (PD-L1). In this review, we will focus on tumor immune escape mechanisms caused by defects in HLA class I APM component expression and/or function in different types of cancer, with emphasis on head and neck cancer (HNC). We will also discuss the immunological implications and clinical relevance of these HLA class I APM abnormalities. Finally, we will describe strategies to counteract defective TA presentation with the expectation that they will enhance tumor recognition and elimination by tumor infiltrating effector T cells. PMID:27264839

  15. Erythrocyte membrane antigen frequencies in patients with Type II congenital smell loss.

    PubMed

    Stateman, William A; Henkin, Robert I; Knöppel, Alexandra B; Flegel, Willy A

    2015-01-01

    The objective of this study was to determine whether there are genetic factors associated with Type II congenital smell loss. The expression frequencies of 16 erythrocyte antigens among patients with Type II congenital smell loss were determined and compared to those of a large control group. Blood samples were obtained from 99 patients with Type II congenital smell loss. Presence of the erythrocyte surface antigens A, B, M, N, S, s, Fy(a), Fy(b), D, C, c, E, e, K, Jk(a), and Jk(b) was analyzed by blood group serology. Comparisons of expression frequencies of these antigens were made between the patients and a large control group. Patients tested for the Duffy b antigen (Fy(b) haplotype) exhibited a statistically significant 11% decrease in expression frequency compared to the controls. There were no significant differences between patients and controls in the expression frequencies for all other erythrocyte antigens (A, B, M, N, S, s, Fy(a), D, C, c, E, e, K, Jk(a), or Jk(b)). These findings describe the presence of a previously unrevealed genetic tendency among patients with Type II congenital smell loss related to erythrocyte surface antigen expression. The deviation in expression rate of Duffy b suggests a target gene and chromosome region in which future research into this form of congenital smell loss may reveal a more specific genetic basis for Type II congenital smell loss. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Erythrocyte Membrane Antigen Frequencies in Patients with Type II Congenital Smell Loss

    PubMed Central

    Stateman, William A.; Henkin, Robert I.; Knöppel, Alexandra; Flegel, Willy A.

    2014-01-01

    OBJECTIVE The objective of this study was to determine whether there are genetic factors associated with Type II congenital smell loss. STUDY DESIGN The expression frequencies of 16 erythrocyte antigens among patients with Type II congenital smell loss were determined and compared to those of a large control group. METHODS Blood samples were obtained from 99 patients with Type II congenital smell loss. Presence of the erythrocyte surface antigens A, B, M, N, S, s, Fya, Fyb, D, C, c, E, e, K, Jka, and Jkb was analyzed by blood group serology. Comparisons of expression frequencies of these antigens were made between the patients and a large control group. RESULTS Patients tested for the Duffy b antigen (Fyb haplotype) exhibited a statistically significant 11% decrease in expression frequency compared to the controls. There were no significant differences between patients and controls in the expression frequencies for all other erythrocyte antigens (A, B, M, N, S, s, Fya, D, C, c, E, e, K, Jka, or Jkb). CONCLUSIONS These findings describe the presence of a previously unrevealed genetic tendency among patients with Type II congenital smell loss related to erythrocyte surface antigen expression. The deviation in expression rate of Duffy b suggests a target gene and chromosome region in which future research into this form of congenital smell loss may reveal a more specific genetic basis for Type II congenital smell loss. PMID:25456515

  17. Differential membrane association properties and regulation of class I and class II Arfs.

    PubMed

    Duijsings, Daniël; Lanke, Kjerstin H W; van Dooren, Sander H J; van Dommelen, Michiel M T; Wetzels, Roy; de Mattia, Fabrizio; Wessels, Els; van Kuppeveld, Frank J M

    2009-03-01

    ADP-ribosylation factor (Arf) proteins are small guanosine triphosphatases (GTPases) that act as major regulators of intracellular vesicular trafficking and secretory organelle pathway integrity. Like all small monomeric GTPases, Arf proteins cycle between a GDP-bound and a GTP-bound state, and this cycling is catalysed by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins. While the class I Arfs, especially Arf1, have been studied extensively, little is known as yet about the function and regulation of class II Arfs, Arf4 and Arf5. In this study, we show that Arf proteins show class-specific dynamic behaviour. Moreover, unlike class I Arfs, membrane association of class II Arfs is resistant to inhibition of large Arf GEFs by Brefeldin A. Through the construction of Arf chimeric proteins, evidence is provided that the N-terminal amphipathic helix and a class-specific residue in the conserved interswitch domain determine the membrane-binding properties of class I and class II Arf proteins. Our results show that fundamental differences exist in behaviour and regulation of these small GTPases.

  18. Treatment of Class II malocclusion with mandibular skeletal anchorage.

    PubMed

    Cakir, Ezgi; Malkoç, Siddik; Kirtay, Mustafa

    2017-06-01

    The aim of this case report was to present the dentofacial changes obtained with bone anchorage in a Class II patient with moderate to severe crowding. A boy, aged 14.5 years, with a dolichofacial type, convex profile, and skeletal and dental Class II relationships was examined. After evaluation, functional treatment with bone anchorage and 4 first premolar extractions was decided as the treatment approach. Miniplates were placed on the buccal shelves of the mandibular third molars. The hook of the anchor was revealed from the first molar level. After surgery, the 4 first premolars were extracted to retract the protrusive mandibular incisors. The maxillary and mandibular first molars were banded, and a lip bumper was inserted to apply elastics and to help distalize the maxillary first molars. Orthodontic forces of 300 to 500 g were applied immediately after placement, originating from the miniscrews to the hooks of the appliance to advance the mandible. After 20 months of treatment, the patient had a dental and skeletal Class I relationship, the mandible was advanced, the maxilla was restrained, and overjet was decreased. The combination of a bone anchor, Class II elastics, and an inner bow is a promising alternative to functional treatment, along with extractions, in Class II patients. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  19. HLA class II peptide-binding and autoimmunity.

    PubMed

    Gebe, J A; Swanson, E; Kwok, William W

    2002-02-01

    The HLA class II locus is located in the 6p21.3 region on the short arm of chromosome 6 and encompasses approximately 700 kb. It consists of over 30 gene loci including the major class II structural genes DP, DQ and DR. While autoimmune disease correlates to specific DP, DQ or DR alleles have been documented, due to the strong linkage disequilibrium between the different HLA alleles, especially between the DR and DQ, the precise identification of susceptible MHC alleles for a number of autoimmune diseases remains elusive.

  20. Efficient vaccine against pandemic influenza: combining DNA vaccination and targeted delivery to MHC class II molecules.

    PubMed

    Grødeland, Gunnveig; Bogen, Bjarne

    2015-06-01

    There are two major limitations to vaccine preparedness in the event of devastating influenza pandemics: the time needed to generate a vaccine and rapid generation of sufficient amounts. DNA vaccination could represent a solution to these problems, but efficacy needs to be enhanced. In a separate line of research, it has been established that targeting of vaccine molecules to antigen-presenting cells enhances immune responses. We have combined the two principles by constructing DNA vaccines that encode bivalent fusion proteins; these target hemagglutinin to MHC class II molecules on antigen-presenting cells. Such DNA vaccines rapidly induce hemagglutinin-specific antibodies and T cell responses in immunized mice. Responses are long-lasting and protect mice against challenge with influenza virus. In a pandemic situation, targeted DNA vaccines could be produced and tested within a month. The novel DNA vaccines could represent a solution to pandemic preparedness in the advent of novel influenza pandemics.

  1. Species specificity and augmentation of responses to class II major histocompatibility complex molecules in human CD4 transgenic mice

    PubMed Central

    1992-01-01

    Murine T cell responses to human class II major histocompatibility complex (MHC) molecules were shown to be a minimum of 20-70-fold lower than responses to allogeneic molecules. Transgenic mice expressing slightly below normal (75-95%) or very high (250-380%) cell surface levels of human CD4 were utilized to determine whether this was due to a species-specific interaction between murine CD4 and class II molecules. Human CD4 was shown to function in signal transduction events in murine T cells based on the ability of anti-human CD4 antibody to synergize with suboptimal doses of anti-murine CD3 antibody in stimulating T cell proliferation. In mice expressing lower levels of human CD4, T cell responses to human class II molecules were enhanced up to threefold, whereas allogeneic responses were unaltered. In mice expressing high levels of human CD4, responses to human class II molecules were enhanced at least 10-fold, whereas allogeneic responses were between one and three times the level of normal responses. The relatively greater enhancement of the response to human class II molecules in both lines argues for a preferential interaction between human CD4 and human class II molecules. In mice expressing lower levels of human CD4, responses to human class II molecules were blocked by antibodies to CD4 of either species, indicating participation by both molecules. In mice expressing high levels of human CD4, responses to both human and murine class II molecules were almost completely blocked with anti-human CD4 antibody, whereas anti-murine CD4 antibody had no effect. However, anti-murine CD4 continued to synergize with anti-CD3 in stimulating T cell proliferation in these mice. Thus, overexpression of human CD4 selectively impaired the ability of murine CD4 to assist in the process of antigen recognition. The ability of human CD4 to support a strong allogeneic response under these conditions indicates that this molecule can interact with murine class II molecules to a

  2. Class II Division 1 in New Dimension: Role of Posterior Transverse Interarch Discrepancy in Class II Division 1 Malocclusion During the Mixed Dentition Period.

    PubMed

    Kapoor, Deepika; Garg, Deepanshu; Mahajan, Neeraj; Bansal, Samriti; Sawhney, Anshul; Kaur, Jasvir; Tripathi, Shashank; Malaviya, Neha

    2015-07-01

    Posterior transverse discrepancy as seen in some cases of Class II Division 1 malocclusion in mixed dentition period can be related to typical skeletofacial characteristics. These features when studied early in the mixed dentition period give a clear view of the desired appropriate treatment plan in a particular case. The purpose of this study was to establish a simple method to determine the posterior (intermolar) transverse discrepancy and craniofacial skeletal features between the dental arches during the mixed dentition in a sample of Class II Division 1 patients to provide diagnostic and therapeutic guidance in the early approach. A sample of 60 Class II Division 1 patients in mixed dention that were divided into 30 Class II Division 1 patients with posterior transverse interarch discrepancy {Class II (I) PTID group} and 30 Class II Division 1 patients without posterior transverse interarch discrepancy {Class II (I) NPTID group}. Thirty Class I subjects in mixed dentition were included as control. The skeletal features of the Class II group without PTID are those of the skeletal Class II associated with 'anatomic' mandibular retrusion (due to a micrognathic mandible) and those of the Class II group with PTID as skeletal Class II associated with only a 'functional' mandibular retrusion (due to a posteriorly displaced mandible of normal size). This study confirmed the role of occlusion in the control of maxillomandibular skeletal relationships.The treatment strategies could be planned on the basis of the transverse component of Class II Division 1 groups in the mixed dentition period.

  3. Characterization of polymorphism within the H2-M MHC class II loci.

    PubMed

    Hermel, E; Yuan, J; Monaco, J J

    1995-01-01

    The products of the class II-like H2-M genes of the major histocompatibility complex are required for class II antigen processing. We sequenced H2-Ma and Mb from several mouse strains to determine whether these genes are polymorphic like the classical H2-A and E genes, or are oligomorphic, like H2-O. Both Mb loci appear to be transcribed and are distinct from each other. Mb1 and Mb2 differ by about 11% at the nucleotide level and are most dissimilar in their second exons (corresponding to the beta 1 domain). Relative to the published Mb1d haplotype sequence, the products of the b, g7, f, and k2 alleles of Mb1 from Mus musculus domesticus and the separate mouse species Mus spretus differ by only one to four amino acids. The majority of the changes occurred in the second exon of Mb1, in contrast to HLA-DMB, the human orthologue. Little polymorphism was seen for Mb2, and Ma was invariant in all strains tested. The similarity of the g7 allele to those from other haplotypes makes it unlikely that the M class II genes play a role in the autoimmune diabetes of NOD strain mice. The M genes are regulated in a manner similar to classical class II genes, in that they are upregulated by IFN-gamma in macrophages, and to a lesser extent by IL4 in B cells. When modeled on the crystal structure of the HLA-DR1 class II molecule, nearly all of the differences between M beta 1 and M beta 2 affect residues facing away from the putative peptide binding groove.

  4. Major histocompatibility complex class II expression distinguishes two distinct B cell developmental pathways during ontogeny

    PubMed Central

    1994-01-01

    All mature B cells coexpress major histocompatibility complex (MHC) class II molecules, I-A and I-E, which are restriction elements required for antigen presentation to CD4+ T cells. However, the expression of class II during the early stages of B cell development has been unclear. We demonstrate here that there is a difference in the expression of class II during murine B cell development in the fetal liver and adult bone marrow (BM). These differences define two distinct B cell developmental pathways. The Fetal-type (FT) pathway is characterized by pre-B and immature IgM+ B cells generated in the fetal liver which initially lack all class II expression. In contrast, the Adult-type (AT) pathway is typified by B cells developing in the adult BM which express class II molecules from the pre-B cell stage. In vitro stromal cell cultures of sorted fetal liver and adult BM pro-B cells indicated that the difference in I-A expression during B cell development is intrinsic to the progenitors. In addition, we show that FT B cell development is not restricted to the fetal liver but occurs in the peritoneal cavities, spleens, liver, and BM of young mice up to at least 1 mo of age. The AT B cell development begins to emerge after birth but is, however, restricted to the BM environment. These findings indicate that there are two distinct B cell developmental pathways during ontogeny, each of which could contribute differentially to the immune repertoire and thus the functions of B cell subsets and lineages. PMID:7913950

  5. Molecular characterization of swine leucocyte antigen class I genes in outbred pig populations.

    PubMed

    Ho, C-S; Lunney, J K; Franzo-Romain, M H; Martens, G W; Lee, Y-J; Lee, J-H; Wysocki, M; Rowland, R R R; Smith, D M

    2009-08-01

    The highly polymorphic swine leucocyte antigen (SLA) genes are one of the most important determinants in swine immune responses to infectious diseases, vaccines, and in transplantation success. Study of SLA influence requires accurate and effective typing methods. We developed a simple and rapid method to type alleles at the three classical SLA class I loci (SLA-1, SLA-3 and SLA-2) using the PCR-sequence-specific primer (PCR-SSP) strategy. This typing system relies on 47 discriminatory PCR primer pairs designed to amplify the SLA class I alleles by groups that have similar sequence motifs. We applied this low-resolution group-specific typing method to characterize the SLA class I alleles present in three outbred pig populations (n = 202). Alleles from 24 class I allele groups corresponding to 56 class I genotypes were detected. We also identified 23 low-resolution SLA class I haplotypes in these pigs and found haplotypes Lr-1.0 (SLA-1*01XX-SLA-3*01XX-SLA-2*01XX) and Lr-4.0 (SLA-1*04XX-SLA-3*04XX-SLA-2*04XX) in all three pig populations with a high prevalence. Over 80% of the pigs examined (n = 162) were found to bear at least one of these haplotypes, resulting in a combined haplotype frequency of nearly 50%. This PCR-SSP-based typing system demonstrates a reliable and unambiguous detection of SLA class I alleles, and can be used to effectively investigate the SLA diversity in outbred pig populations. It will help to identify the role of SLA antigens in disease-resistant pigs and may facilitate the development of effective vaccines.

  6. Coexpression of intercellular adhesion molecule-1 and class I major histocompatibility complex antigens on hepatocyte membrane in chronic viral hepatitis.

    PubMed Central

    Chu, C M; Liaw, Y F

    1993-01-01

    AIMS--To evaluate the role of hepatocyte expression of leucocyte adhesion molecules and major histocompatibility complex (MHC) antigens in the pathogenesis of chronic viral hepatitis. METHODS--The expression of intercellular adhesion molecule 1 (ICAM-1), lymphocyte function associated antigen 3 (LFA-3), and MHC class I and II antigens on hepatocyte membrane in relation to the histological and biochemical activities was studied in patients with chronic B hepatitis, chronic persistent hepatitis (CPH) n = 23; chronic active hepatitis (CAH) n = 20; chronic D hepatitis (CAH) n = 6; and chronic non-A, non-B hepatitis (CPH n = 4, CAM n = 6). Six of the latter were hepatitis C virus antibody positive. RESULTS--In chronic B hepatitis ICAM-1 and MHC-I were expressed significantly more in patients with CAH than in those with CPH (p < 0.001), while the expression of LFA-3 and MHC-II showed no significant difference, irrespective of serum HBeAg or hepatitis B virus DNA. Similar findings were noted in non-A, non-B hepatitis. Regardless of the viral aetiology, patients with CAH had a significantly higher degree of ICAM-1 and MHC-I expression than LFA-3 (p < 0.001 v ICAM-1 and MHC-I, respectively) and MHC-II (p < 0.001 v ICAM-1 and MHC-I, respectively) expression. Those with CPH showed little or no difference in the expression of these four molecules. Furthermore, serum ALT values positively correlated with the hepatocyte expression of ICAM-1 (p < 0.001) and MHC-I (p < 0.001), but not LFA-3 (p > 0.05) and MHC-II (p > 0.05). CONCLUSIONS--In chronic viral hepatitis hepatocyte expression of ICAM-1 and MHC-I might be important for immunosurveillance against virally infected hepatocytes, while the expression of LFA-3 and MHC-II does not seem to have a role in the pathogenesis of chronic viral hepatitis. Images PMID:7902850

  7. Cytosolic aminopeptidases influence MHC class I-mediated antigen presentation in an allele-dependent manner.

    PubMed

    Kim, Eunkyung; Kwak, Heechun; Ahn, Kwangseog

    2009-12-01

    Antigenic peptides presented by MHC class I molecules are generated mainly by the proteasome in the cytosol. Several cytosolic aminopeptidases further trim proteasomal products to form mature epitopes or individual amino acids. However, the distinct function of cytosolic aminopeptidases in MHC class I Ag processing remains to be elucidated. In this study, we show that cytosolic aminopeptidases differentially affect the cell surface expression of MHC class I molecules in an allele-dependent manner in human cells. In HeLa cells, knockdown of puromycin-sensitive aminopeptidase (PSA) by RNA interference inhibited optimal peptide loading of MHC class I molecules, and their cell surface expression was correspondingly reduced. In contrast, depletion of bleomycin hydrolase (BH) enhanced optimal peptide loading and cell surface expression of MHC class I molecules. We did not find evidence on the effect of leucine aminopeptidase knockdown on the MHC class I Ag presentation. Moreover, we demonstrated that PSA and BH influence the peptide loading and surface expression of MHC class I in an allele-specific manner. In the absence of either PSA or BH, the surface expression and peptide-dependent stability of HLA-A68 were reduced, whereas those of HLA-B15 were enhanced. The surface expression and peptide-dependent stability of HLA-A3 were enhanced by BH knockdown, although those of HLA-B8 were increased in PSA-depleted conditions.

  8. Differential presentation of tumor antigen-derived epitopes by MHC-class I and antigen-positive tumor cells.

    PubMed

    Held, Gerhard; Neumann, Frank; Sturm, Christine; Kaestner, Lars; Dauth, Nina; de Bruijn, Diederik R; Renner, Christoph; Lipp, Peter; Pfreundschuh, Michael

    2008-10-15

    SSX2 is a member of the family of cancer/testis antigens. The SSX2 derived peptide SSX2(103-111) has been shown to be presented to cytotoxic T-lymphocytes (CTL) by Major-Histocompatibility (MHC) Class-I complexes after endogenous processing, more precisely by the allele HLA-A*0201. The HLA-A*0201- and SSX2-positive melanoma cell line SK-Mel-37 but not Me275 had been shown to elicit reactivity in SSX2(103-111) specific cytotoxic T-lymphocytes. To analyze the correlation between SSX2(103-111) presentation and T-cell stimulation, we intended to visualize presentation of SSX2(103-111) in these melanoma cell lines. Fab-antibodies were established from a human phage library with specificity for SSX2(103-111)/HLA-A*0201 complexes (but non-reactive with HLA-A*0201 or SSX2(103-111) alone) and used to visualize the presentation of SSX2(103-111) in the context of HLA-A*0201 by fluorescence microscopy. Presentation of SSX2(103-111) the context of HLA-A*0201 was demonstrated for the majority of SK-Mel-37, but for only a small fraction (<1%) of Me275 as indicated by a clear membrane-staining pattern in fluorescence microscopy. The presentation of SSX2(103-111) on SK-Mel37 and Me275, but not the expression of the SSX2 protein correlated with the capability of these cells to stimulate cells of an SSX2(103-111)-specific T-cell clone. MHC-peptide specific antibodies are a valuable tool for the analysis of antigenic peptides in the context of MHC-I molecules and for the structural definition of immunodominant epitopes.

  9. Treatment of class ii in adulthood by forsus frd device

    PubMed Central

    DE NUCCIO, F.; D’EMIDIO, M.M.; DE NUCCIO, F.

    2016-01-01

    SUMMARY Objectives Scientific research data show that the Forsus FRD seems to have a great potential in the correction of Class II in childhood. The conclusions reached by the various Authors seem to support the hypothesis of an exclusively or mainly dentoalveolar correction, as the skeletal correction seems to have no – or little – appreciable results. In the light of such provided by different Authors, the potential of dentoalveolar compensation in adult patients with mild skeletal class II was investigated. Materials and methods At the UOC (Complex Operative Unit) of Orthodontics at “G. Eastman” Hospital Rome, 3 cases of skeletal class II mild (ANB <5 °) in adult patients were selected. They were treated with fixed multibracket appliance and Forsus EZ2 module. Cephalometric tracings were compared at the beginning and at the end of the treatment in order to assess the skeletal and dentoalveolar changes. Results The occlusal correction was achieved through a dentoalveolar compensation characterized by the flaring of the lower teeth. Conclusions Forsus FRD equipment is an excellent compromise for the correction of mild Class II, even during the post development age. The resulting correction is appreciated at dental alveolar level with a mesial movement of the incisors and molars. PMID:28280539

  10. MHC class II DR allelic diversity in bighorn sheep

    USDA-ARS?s Scientific Manuscript database

    We hypothesized that decreased diversity and/or unique polymorphisms in MHC class II alleles of bighorn sheep (BHS, Ovis canadensis) are responsible for lower titer of antibodies against Mannheimia haemolytica leukotoxin, in comparison to domestic sheep (DS, Ovis aries). To test this hypothesis, DRA...

  11. 14 CFR 21.223 - Class II provisional airworthiness certificates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... provisional aircraft flight manual containing the limitations established by §§ 21.83(h), 91.317, and 121.207... TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Provisional Airworthiness Certificates... applicant is entitled to a Class II provisional airworthiness certificate for an aircraft for which a...

  12. 14 CFR 21.223 - Class II provisional airworthiness certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... provisional aircraft flight manual containing the limitations established by §§ 21.83(h), 91.317, and 121.207... TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Provisional Airworthiness Certificates... applicant is entitled to a Class II provisional airworthiness certificate for an aircraft for which a...

  13. 14 CFR 21.223 - Class II provisional airworthiness certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... provisional aircraft flight manual containing the limitations established by §§ 21.83(h), 91.317, and 121.207... TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Provisional Airworthiness Certificates... applicant is entitled to a Class II provisional airworthiness certificate for an aircraft for which a...

  14. 14 CFR 21.223 - Class II provisional airworthiness certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... (f) The aircraft must be supplied with a provisional aircraft flight manual containing the... TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Provisional Airworthiness Certificates... airworthiness certificate for an aircraft for which a Class II provisional type certificate has been issued...

  15. 14 CFR 21.223 - Class II provisional airworthiness certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... provisional aircraft flight manual containing the limitations established by §§ 21.83(h), 91.317, and 121.207... TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Provisional Airworthiness Certificates... applicant is entitled to a Class II provisional airworthiness certificate for an aircraft for which a...

  16. Class II malocclusion nonextraction treatment with growth control*

    PubMed Central

    Assunção, Zilda Lúcia Valentim

    2014-01-01

    The present study reports a case of Angle Class II malocclusion treatment of a male growing patient with 10-mm overjet, excessive overbite and transverse maxillary deficiency. The case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), with DI equal to or greater than 10, as a requirement for the title of certified by the BBO. PMID:25628088

  17. Staphylococcus-mediated T-cell activation and spontaneous natural killer cell activity in the absence of major histocompatibility complex class II molecules

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Hoynowski, S. M.; Woods, K. M.; Armstrong, J. W.; Beharka, A. A.; Iandolo, J. J.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    We used major histocompatibility complex class II antigen-deficient transgenic mice to show that in vitro natural killer cell cytotoxicity and T-cell activation by staphylococcal exotoxins (superantigens) are not dependent upon the presence of major histocompatibility complex class II molecules. T cells can be activated by exotoxins in the presence of exogenously added interleukin 1 or 2 or in the presence of specific antibody without exogenously added cytokines.

  18. Staphylococcus-mediated T-cell activation and spontaneous natural killer cell activity in the absence of major histocompatibility complex class II molecules

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Hoynowski, S. M.; Woods, K. M.; Armstrong, J. W.; Beharka, A. A.; Iandolo, J. J.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    We used major histocompatibility complex class II antigen-deficient transgenic mice to show that in vitro natural killer cell cytotoxicity and T-cell activation by staphylococcal exotoxins (superantigens) are not dependent upon the presence of major histocompatibility complex class II molecules. T cells can be activated by exotoxins in the presence of exogenously added interleukin 1 or 2 or in the presence of specific antibody without exogenously added cytokines.

  19. Effect of temperature on the expression of major histocompatibility complex class-I antigens.

    PubMed

    Aboud, M; Segal, S; Priel, E; Blair, D G; O'Hara, B

    1992-06-01

    In the present study we investigated the effect of temperature on MHC class-I gene expression in BALB/C 3T3 cells incubated for 5 days at 34 degrees C, 37 degrees C and 39 degrees C. FACS analysis revealed no significant difference in the cell surface expression of any of the 3 major class-I antigens at 34 degrees C and 37 degrees C. Strikingly, however, when the level of the respective mRNA was determined, only that of the H-2K was comparable at both temperatures, whereas the levels of the H-2D and H-2L mRNA were profoundly higher at 37 degrees C. These data appear to reflect a differential temperature-related transcriptional control of the different class-I genes or a different temperature effect on the stability of their mRNA. The absence of a parallel increase in surface expression of the corresponding H-2D and H-2L antigens may result from some translational or post-translational limiting factors. At 39 degrees C, however, these limiting factors seem to be overcome since the surface expression of all the 3 antigens was remarkably increased although the level of their encoding mRNA was rather lower than in 37 degrees C. This stimulatory effect might be ascribed to heat shock proteins which are known to arise in cells at heat or other stress conditions. They participate in assembly and disassembly of various protein complexes and in transport of certain proteins across intracellular membranes. Such proteins may have arisen in our cells at 39 degrees C and facilitated the intracellular assembly of the class-I molecules and their transport to the cell surface. The possible implication of such heat shock proteins in the anti-tumor effect of hyperthermia is discussed.

  20. Association of HLA class I antigen abnormalities with disease progression and early recurrence in prostate cancer.

    PubMed

    Seliger, Barbara; Stoehr, Robert; Handke, Diana; Mueller, Anja; Ferrone, Soldano; Wullich, Bernd; Tannapfel, Andrea; Hofstaedter, Ferdinand; Hartmann, Arndt

    2010-04-01

    Defects in HLA class I antigen processing machinery (APM) component expression often have a negative impact on the clinical course of tumors and on the response to T cell-based immunotherapy. Since only scant information is available about the frequency and clinical significance of HLA class I APM component abnormalities in prostate cancer, the APM component expression pattern was analyzed in 59 primary prostate carcinoma, adjacent normal tissues, as well as in prostate carcinoma cell lines. The IFN-gamma inducible proteasome subunits LMP2 and LMP7, TAP1, TAP2, calnexin, calreticulin, ERp57, and tapasin are strongly expressed in the cytoplasm of normal prostate cells, whereas HLA class I heavy chain (HC) and beta(2)-microglobulin are expressed on the cell surface. Most of the APM components were downregulated in a substantial number of prostate cancers. With the exception of HLA class I HC, TAP2 and ERp57 not detectable in about 0.5% of tumor lesions, all other APM components were not detected in at least 21% of lesions analyzed. These APM component defects were associated with a higher Gleason grade of tumors and an early disease recurrence. Prostate carcinoma cell lines also exhibit a heterogeneous, but reduced constitutive APM component expression pattern associated with lack or reduced HLA class I surface antigens, which could be upregulated by IFN-gamma. Our results suggest that HLA class I APM component abnormalities are mainly due to regulatory mechanisms, play a role in the clinical course of prostate cancer and on the outcome of T cell-based immunotherapies.

  1. Characterisation of maternal human leukocyte antigen class I antibodies in suspected foetal and neonatal alloimmune thrombocytopenia.

    PubMed

    Refsum, E; Mörtberg, A; Dahl, J; Meinke, S; Auvinen, M-K; Westgren, M; Reilly, M; Höglund, P; Wikman, A

    2017-02-01

    To investigate the specificities and level of HLA class I antibodies in selected cases referred for suspected foetal and neonatal alloimmune thrombocytopenia (FNAIT). FNAIT occurs in 1 : 1-2000 live births, whereas maternal immunisation against human leukocyte antigen (HLA) class I is common. Whether HLA class I antibodies alone can cause FNAIT is debatable. A total of 260 patient samples were referred between 2007 and 2012. Referrals with maternal HLA class I antibodies and no other cause for the neonatal thrombocytopenia were included for analysis (cases, n = 23). HPA-1a negative mothers were excluded. Control groups were screened positive mothers of healthy neonates (controls, n = 33) and female blood donors (blood donors, n = 19). LABScreen single antigen HLA class I beads was used for antibody analysis. Clinical records were reviewed for cases. All groups had broad antibody reactivity. Cases had more antibodies with high SFI levels compared with the controls (SFI>9999; medians 26, 6 and 0; P < 0·05) and higher overall median HLA-ABC and HLA-B SFI (P < 0·05). Many of the antibodies were reactive with rare alleles. When reviewing the clinical records, several of the cases had other contributing factors to the thrombocytopenia. There was no correlation between foetal platelet count and antibody levels. Mothers of thrombocytopenic neonates had higher levels of HLA class I antibodies compared with control groups of women with healthy children and female blood donors. However, clinical outcome and antibody response correlated poorly in the heterogeneous case group, indicating a multifactorial cause to the thrombocytopenia in the majority of cases. © 2016 British Blood Transfusion Society.

  2. Expression and functional properties of the Streptococcus intermedius surface protein antigen I/II.

    PubMed

    Petersen, F C; Pasco, S; Ogier, J; Klein, J P; Assev, S; Scheie, A A

    2001-07-01

    Streptococcus intermedius is associated with deep-seated purulent infections. In this study, we investigated expression and functional activities of antigen I/II in S. intermedius. The S. intermedius antigen I/II appeared to be cell surface associated, with a molecular mass of approximately 160 kDa. Northern blotting indicated that the S. intermedius NCTC 11324 antigen I/II gene was transcribed as a monocistronic message. Maximum expression was seen during the early exponential phase. Insertional inactivation of the antigen I/II gene resulted in reduced hydrophobicity during early exponential phase, whereas no effect was detected during mid- and late exponential phases. Binding to human fibronectin and laminin was reduced in the isogenic mutant, whereas binding to human collagen types I and IV and to rat collagen type I was not significant for either the wild type or the mutant. Compared to the wild type, the capacity of the isogenic mutant to induce interleukin 8 (IL-8) release by THP-1 monocytic cells was significantly reduced. The results indicate that the S. intermedius antigen I/II is involved in adhesion to human receptors and in IL-8 induction.

  3. Tracking antigen-specific CD8⁺ T cells using MHC class I multimers.

    PubMed

    Alanio, Cécile; Bouvier, Isabelle; Jusforgues-Saklani, Hélène; Albert, Matthew L

    2013-01-01

    The tracking of epitope-specific T cells is a useful approach for the study of adaptive immune responses. This protocol describes how Major Histocompatibility Complex Class I (MHC-I) multimers can be used to stain, enrich, and enumerate (rare) populations of CD8(+) T cells specific for a given antigen. It provides the detailed steps for multimer labeling, magnetic enrichment, and cytometric analysis. Additionally, it provides informations for multiplexing experiments in order to achieve simultaneous detection of multiple antigenic specificities, and strategies for coupling the protocol with functional assays (e.g., intracellular cytokine staining). Future developments in cytometric systems (e.g., mass spectroscopy-based cytometry) and gene expression studies (e.g., single cell PCR) will extend these approaches and provide an unprecedented assessment of the immune repertoire.

  4. Lipopeptides: a novel antigen repertoire presented by major histocompatibility complex class I molecules.

    PubMed

    Morita, Daisuke; Sugita, Masahiko

    2016-10-01

    Post-translationally modified peptides, such as those containing either phosphorylated or O-glycosylated serine/threonine residues, may be presented to cytotoxic T lymphocytes (CTLs) by MHC class I molecules. Most of these modified peptides are captured in the MHC class I groove in a similar manner to that for unmodified peptides. N-Myristoylated 5-mer lipopeptides have recently been identified as a novel chemical class of MHC class I-presented antigens. The rhesus classical MHC class I allele, Mamu-B*098, was found to be capable of binding N-myristoylated lipopeptides and presenting them to CTLs. A high-resolution X-ray crystallographic analysis of the Mamu-B*098:lipopeptide complex revealed that the myristic group as well as conserved C-terminal serine residue of the lipopeptide ligand functioned as anchors, whereas the short stretch of three amino acid residues located in the middle of the lipopeptides was only exposed externally with the potential to interact directly with specific T-cell receptors. Therefore, the modes of lipopeptide-ligand interactions with MHC class I and with T-cell receptors are novel and fundamentally distinct from that for MHC class I-presented peptides. Another lipopeptide-presenting MHC class I allele has now been identified, leading us to the prediction that MHC class I molecules may be separated on a functional basis into two groups: one presenting long peptides and the other presenting short lipopeptides. Since the N-myristoylation of viral proteins is often linked to pathogenesis, CTLs capable of sensing N-myristoylation may serve to control pathogenic viruses, raising the possibility for the development of a new type of lipopeptide vaccine. © 2016 John Wiley & Sons Ltd.

  5. Immunoselection in vivo: independent loss of MHC class I and melanocyte differentiation antigen expression in metastatic melanoma.

    PubMed

    Jäger, E; Ringhoffer, M; Altmannsberger, M; Arand, M; Karbach, J; Jäger, D; Oesch, F; Knuth, A

    1997-04-10

    Peptides derived from melanocyte differentiation antigens have been identified as targets for MHC class I-restricted cytolytic T lymphocytes (CTLs) in human melanoma Regression of antigen-expressing tumors as well as selection of antigen-loss variants in the presence of antigen-specific CTLs have previously been reported. In the present study, we determined the expression of the melanocyte differentiation antigens Melan A/MART-1 and tyrosinase by mRNA analysis and by immunohistochemical staining with the monoclonal antibodies (MAbs) A103 and T311. Co-expression of Melan A/MART-1 and tyrosinase was detected by both methods in 18/20 melanomas tested. However, immunohistochemistry provided additional information on intensity and microheterogeneity of antigen expression that cannot be detected by mRNA analysis as a molecular basis for the escape from CTL recognition of antigen-negative tumor cells. Comparative analysis of repeated biopsies of metastatic lesions in 5 HLA-A2+ patients showed a gradual loss of Melan A/MART-1 expression in 4/5 and of tyrosinase in 2/5 samples in association with tumor progression. However, 3 of these patients had growing antigen-positive tumors in the presence of antigen-specific CTLs. This led us to assess the expression of MHC class I, the essential restriction element for CTL recognition, and of HLA-A2. We found an unexpectedly high frequency of MHC class I-negative tumors (9/20). Loss of MHC class I expression was detected in 3/5 progressive tumors and isolated loss of HLA-A2 in 1/5 tumors. Our results suggest that strategies enhancing the expression of MHC class I and tumor-associated antigens need to be considered in attempts at making vaccination more effective.

  6. Inclusion of Strep-Tag II in design of antigen receptors for T cell immunotherapy

    PubMed Central

    Liu, Lingfeng; Sommermeyer, Daniel; Cabanov, Alexandra; Kosasih, Paula; Hill, Tyler; Riddell, Stanley R

    2016-01-01

    The tactical introduction of Strep-tag II into synthetic antigen receptors provides engineered T cells with a marker for identification and rapid purification, and a functional element for selective antibody coated microbead-driven large-scale expansion. Such receptor designs can be applied to chimeric antigen receptors of different ligand specificities and costimulatory domains, and to T cell receptors to facilitate cGMP manufacturing of adoptive T cell therapies to treat cancer and other diseases. PMID:26900664

  7. HLA class II sequence variants influence tuberculosis risk in populations of European ancestry.

    PubMed

    Sveinbjornsson, Gardar; Gudbjartsson, Daniel F; Halldorsson, Bjarni V; Kristinsson, Karl G; Gottfredsson, Magnus; Barrett, Jeffrey C; Gudmundsson, Larus J; Blondal, Kai; Gylfason, Arnaldur; Gudjonsson, Sigurjon Axel; Helgadottir, Hafdis T; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Karason, Ari; Kardum, Ljiljana Bulat; Knežević, Jelena; Kristjansson, Helgi; Kristjansson, Mar; Love, Arthur; Luo, Yang; Magnusson, Olafur T; Sulem, Patrick; Kong, Augustine; Masson, Gisli; Thorsteinsdottir, Unnur; Dembic, Zlatko; Nejentsev, Sergey; Blondal, Thorsteinn; Jonsdottir, Ingileif; Stefansson, Kari

    2016-03-01

    Mycobacterium tuberculosis infections cause 9 million new tuberculosis cases and 1.5 million deaths annually. To identify variants conferring risk of tuberculosis, we tested 28.3 million variants identified through whole-genome sequencing of 2,636 Icelanders for association with tuberculosis (8,162 cases and 277,643 controls), pulmonary tuberculosis (PTB) and M. tuberculosis infection. We found association of three variants in the region harboring genes encoding the class II human leukocyte antigens (HLAs): rs557011[T] (minor allele frequency (MAF) = 40.2%), associated with M. tuberculosis infection (odds ratio (OR) = 1.14, P = 3.1 × 10(-13)) and PTB (OR = 1.25, P = 5.8 × 10(-12)), and rs9271378[G] (MAF = 32.5%), associated with PTB (OR = 0.78, P = 2.5 × 10(-12))--both located between HLA-DQA1 and HLA-DRB1--and a missense variant encoding p.Ala210Thr in HLA-DQA1 (MAF = 19.1%, rs9272785), associated with M. tuberculosis infection (P = 9.3 × 10(-9), OR = 1.14). We replicated association of these variants with PTB in samples of European ancestry from Russia and Croatia (P < 5.9 × 10(-4)). These findings show that the HLA class II region contributes to genetic risk of tuberculosis, possibly through reduced presentation of protective M. tuberculosis antigens to T cells.

  8. Major histocompatibility complex class II (MHC II) expression during the development of human fetal cerebral occipital lobe, cerebellum, and hematopoietic organs.

    PubMed

    Wierzba-Bobrowicz, T; Kosno-Kruszewska, E; Gwiazda, E; Lechowicz, W

    2000-01-01

    In adults, under physiological conditions proteins of the major histocompatibility complex, class II (MHC II) molecules are synthesized and then presented on the surface of the cells known under a common name as antigen presenting cells (APCs). Dendritic cells (DCs), microglia, macrophages, ameboid microglia and lymphocytes B are qualified as APCs. The aim of present study was to evaluate the expression of MHC II molecules in the central nervous system (CNS) and hematopoietic organs during the fetal development. Observations were made on the cerebral occipital lobe, cerebellum, thymus, spleen and liver of 30 normal human fetuses, between 11 and 22 week of gestation (GW). Histological, histochemical and immunohistochemical techniques were used to identify cells with expression of MHC II molecules. In the brain, MHC II molecules were detected on macrophages/ameboid microglia in meninges, choroid plexus and single cells of ramified microglia in deeper layers of the cortex and white matter. In the other organs besides macrophages and dendritic cells, MHC II molecules were also immunopositive in thymic epithelial cells, and in the spleen and liver also in other cells of stroma and lobule. The expression of MHC II molecules on so extensive population of cells, at an early stage of the fetal development, may evidence their significant involvement in histogenesis and morphogenesis. It seems that in adults the complex of MHC II with protein is originated from the foreign antigen. On the contrary, during normal fetal development the complex of MHC II with protein origins most probably from the fetus own structures.

  9. Ethanol Metabolism Alters Major Histocompatibility Complex Class I-Restricted Antigen Presentation In Liver Cells

    PubMed Central

    Osna, Natalia A.; White, Ronda L.; Thiele, Geoffrey M.; Donohue, Terrence M.

    2009-01-01

    The proteasome is a major enzyme that cleaves proteins for antigen presentation. Cleaved peptides traffic to the cell surface, where they are presented in the context of MHC class I. Recognition of these complexes by cytotoxic T lymphocytes is crucial for elimination of cells bearing “non-self” proteins. Our previous studies revealed that ethanol suppresses proteasome function in ethanol-metabolizing liver cells. We hypothesized that proteasome suppression reduces the hydrolysis of antigenic peptides, thereby decreasing the presentation of the peptide-MHC class I-complexes on the cell surface. To test this, we used the mouse hepatocyte cell line (CYP2E1/ADH-transfected HepB5 cells) or primary mouse hepatocytes, both derived from livers of C57Bl/6 mice, which present the ovalbumin peptide, SIINFEKL, complexed with H2Kb. To induce H2Kb expression, HepB5 cells were treated with interferon gamma (IFNγ) and then exposed to ethanol. In these cells, ethanol metabolism decreased not only proteasome activity, but also hydrolysis of the C-extended peptide, SIINFEKL-TE and the presentation of SIINFEKL-H2Kb complexes measured after the delivery of SIINFEKL-TE to cytoplasm. The suppressive effects of ethanol were, in part, attributed to ethanol-elicited impairment of IFNγ signaling. However, in primary hepatocytes, even in the absence of IFNγ, we observed a similar decline in proteasome activity and antigen presentation after ethanol exposure. We conclude that proteasome function is directly suppressed by ethanol metabolism and indirectly, by preventing the activating effects of IFNγ. Ethanol-elicited reduction in proteasome activity contributes to the suppression of SIINFEKL-H2Kb presentation on the surface of liver cells. Immune response to viral antigens plays a crucial role in the pathogenesis of hepatitis C or B viral infections (HCV and HBV, respectively). Professional antigen-presenting cells (dendritic cells and macrophages) are responsible for priming the

  10. The same ELA class II risk factors confer equine insect bite hypersensitivity in two distinct populations.

    PubMed

    Andersson, Lisa S; Swinburne, June E; Meadows, Jennifer R S; Broström, Hans; Eriksson, Susanne; Fikse, W Freddy; Frey, Rebecka; Sundquist, Marie; Tseng, Chia T; Mikko, Sofia; Lindgren, Gabriella

    2012-03-01

    Insect bite hypersensitivity (IBH) is a chronic allergic dermatitis common in horses. Affected horses mainly react against antigens present in the saliva from the biting midges, Culicoides ssp, and occasionally black flies, Simulium ssp. Because of this insect dependency, the disease is clearly seasonal and prevalence varies between geographical locations. For two distinct horse breeds, we genotyped four microsatellite markers positioned within the MHC class II region and sequenced the highly polymorphic exons two from DRA and DRB3, respectively. Initially, 94 IBH-affected and 93 unaffected Swedish born Icelandic horses were tested for genetic association. These horses had previously been genotyped on the Illumina Equine SNP50 BeadChip, which made it possible to ensure that our study did not suffer from the effects of stratification. The second population consisted of 106 unaffected and 80 IBH-affected Exmoor ponies. We show that variants in the MHC class II region are associated with disease susceptibility (p (raw) = 2.34 × 10(-5)), with the same allele (COR112:274) associated in two separate populations. In addition, we combined microsatellite and sequencing data in order to investigate the pattern of homozygosity and show that homozygosity across the entire MHC class II region is associated with a higher risk of developing IBH (p = 0.0013). To our knowledge this is the first time in any atopic dermatitis suffering species, including man, where the same risk allele has been identified in two distinct populations.

  11. Relation of HLA class I and II supertypes with spontaneous clearance of hepatitis C virus.

    PubMed

    Kuniholm, M H; Anastos, K; Kovacs, A; Gao, X; Marti, D; Sette, A; Greenblatt, R M; Peters, M; Cohen, M H; Minkoff, H; Gange, S J; Thio, C L; Young, M A; Xue, X; Carrington, M; Strickler, H D

    2013-01-01

    Human leukocyte antigen (HLA) genotype has been associated with the probability of spontaneous clearance of hepatitis C virus (HCV). However, no prior studies have examined whether this relationship may be further characterized by grouping HLA alleles according to their supertypes, defined by their binding capacities. There is debate regarding the most appropriate method to define supertypes. Therefore, previously reported HLA supertypes (46 class I and 25 class II) were assessed for their relation with HCV clearance in a population of 758 HCV-seropositive women. Two HLA class II supertypes were significant in multivariable models that included: (i) supertypes with significant or borderline associations with HCV clearance after adjustment for multiple tests, and (ii) individual HLA alleles not part of these supertypes, but associated with HCV clearance in our prior study in this population. Specifically, supertype DRB3 (prevalence ratio (PR)=0.4; P=0.004) was associated with HCV persistence, whereas DR8 (PR=1.8; P=0.01) was associated with HCV clearance. Two individual alleles (B*57:01 and C*01:02) associated with HCV clearance in our prior study became nonsignificant in analysis that included supertypes, whereas B*57:03 (PR=1.9; P=0.008) and DRB1*07:01 (PR=1.7; P=0.005) retained their significance. These data provide epidemiologic support for the significance of HLA supertypes in relation to HCV clearance.

  12. HLA class II genes modulate vaccine-induced antibody responses to affect HIV-1 acquisition.

    PubMed

    Prentice, Heather A; Tomaras, Georgia D; Geraghty, Daniel E; Apps, Richard; Fong, Youyi; Ehrenberg, Philip K; Rolland, Morgane; Kijak, Gustavo H; Krebs, Shelly J; Nelson, Wyatt; DeCamp, Allan; Shen, Xiaoying; Yates, Nicole L; Zolla-Pazner, Susan; Nitayaphan, Sorachai; Rerks-Ngarm, Supachai; Kaewkungwal, Jaranit; Pitisuttithum, Punnee; Ferrari, Guido; McElrath, M Juliana; Montefiori, David C; Bailer, Robert T; Koup, Richard A; O'Connell, Robert J; Robb, Merlin L; Michael, Nelson L; Gilbert, Peter B; Kim, Jerome H; Thomas, Rasmi

    2015-07-15

    In the RV144 vaccine trial, two antibody responses were found to correlate with HIV-1 acquisition. Because human leukocyte antigen (HLA) class II-restricted CD4(+) T cells are involved in antibody production, we tested whether HLA class II genotypes affected HIV-1-specific antibody levels and HIV-1 acquisition in 760 individuals. Indeed, antibody responses correlated with acquisition only in the presence of single host HLA alleles. Envelope (Env)-specific immunoglobulin A (IgA) antibodies were associated with increased risk of acquisition specifically in individuals with DQB1*06. IgG antibody responses to Env amino acid positions 120 to 204 were higher and were associated with decreased risk of acquisition and increased vaccine efficacy only in the presence of DPB1*13. Screening IgG responses to overlapping peptides spanning Env 120-204 and viral sequence analysis of infected individuals defined differences in vaccine response that were associated with the presence of DPB1*13 and could be responsible for the protection observed. Overall, the underlying genetic findings indicate that HLA class II modulated the quantity, quality, and efficacy of antibody responses in the RV144 trial.

  13. Lack of associations between HLA class II alleles and resistance to HIV-1 infection among white, non-Hispanic homosexual men.

    PubMed

    Liu, Chenglong; Carrington, Mary; Kaslow, Richard A; Gao, Xiaojiang; Rinaldo, Charles R; Jacobson, Lisa P; Margolick, Joseph B; Phair, John; O'Brien, Stephen J; Detels, Roger

    2004-10-01

    HLA class II alleles were molecularly typed for 100 high-risk seronegative men and 184 low-risk seroconverters from the Multicenter AIDS Cohort Study (MACS). Seven resistant individuals homozygous for CCR5 Delta32 deletions were excluded from analysis. In the univariate analysis, no significant HLA class II associations with resistance/susceptibility to HIV type 1 infection were identified. However, the transporter associated with antigen presentation 2 (TAP2) Ala 665 variant associated with resistance in earlier analyses in the MACS was in linkage disequilibrium with some HLA class II alleles. After adjusting for the established associations with HLA-A*0205 subgroup and TAP2 Ala 665 variant, no HLA class II alleles were independently associated with resistance/susceptibility to HIV-1 infection. Other genetic factors in the HLA class II-TAP region of the major histocompatibility complex might be involved.

  14. Development of MHC class I and II B primers in common carp and its molecular characterization.

    PubMed

    Jia, Zhiying; Chi, Xifeng; Li, Chitao; Shi, Lianyu

    2010-08-01

    The major histocompatibility complex (MHC) has an important role in immune response and is known as the most polymorphic locus in vertebrates. We developed three pairs of polymerase chain reaction primers of the alpha-2 domain (exon 3) of MHC class I and the beta-2 (exon 3) and beta-3 domains (exon 4) of MHC class II B gene in the German mirror common carp (Cyprinus carpio L.). We analyzed the three loci in a population of 65 individuals that had suffered the serious disease of gill rot. Five to six variable nucleotide sites and two to six variable amino acid sites (71.43%) were detected in the exon sequence of the sampled populations, indicating that many of them corresponded to amino acids involved in antigen recognition. Deviation from Hardy-Weinberg equilibrium and linkage disequilibrium were differentially found in some loci, which will be important for further study of disease resistance/susceptibility and population evolution.

  15. Susceptibility of amphibians to chytridiomycosis is associated with MHC class II conformation

    PubMed Central

    Bataille, Arnaud; Cashins, Scott D.; Grogan, Laura; Skerratt, Lee F.; Hunter, David; McFadden, Michael; Scheele, Benjamin; Brannelly, Laura A.; Macris, Amy; Harlow, Peter S.; Bell, Sara; Berger, Lee; Waldman, Bruce

    2015-01-01

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) can cause precipitous population declines in its amphibian hosts. Responses of individuals to infection vary greatly with the capacity of their immune system to respond to the pathogen. We used a combination of comparative and experimental approaches to identify major histocompatibility complex class II (MHC-II) alleles encoding molecules that foster the survival of Bd-infected amphibians. We found that Bd-resistant amphibians across four continents share common amino acids in three binding pockets of the MHC-II antigen-binding groove. Moreover, strong signals of selection acting on these specific sites were evident among all species co-existing with the pathogen. In the laboratory, we experimentally inoculated Australian tree frogs with Bd to test how each binding pocket conformation influences disease resistance. Only the conformation of MHC-II pocket 9 of surviving subjects matched those of Bd-resistant species. This MHC-II conformation thus may determine amphibian resistance to Bd, although other MHC-II binding pockets also may contribute to resistance. Rescuing amphibian biodiversity will depend on our understanding of amphibian immune defence mechanisms against Bd. The identification of adaptive genetic markers for Bd resistance represents an important step forward towards that goal. PMID:25808889

  16. Susceptibility of amphibians to chytridiomycosis is associated with MHC class II conformation.

    PubMed

    Bataille, Arnaud; Cashins, Scott D; Grogan, Laura; Skerratt, Lee F; Hunter, David; McFadden, Michael; Scheele, Benjamin; Brannelly, Laura A; Macris, Amy; Harlow, Peter S; Bell, Sara; Berger, Lee; Waldman, Bruce

    2015-04-22

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) can cause precipitous population declines in its amphibian hosts. Responses of individuals to infection vary greatly with the capacity of their immune system to respond to the pathogen. We used a combination of comparative and experimental approaches to identify major histocompatibility complex class II (MHC-II) alleles encoding molecules that foster the survival of Bd-infected amphibians. We found that Bd-resistant amphibians across four continents share common amino acids in three binding pockets of the MHC-II antigen-binding groove. Moreover, strong signals of selection acting on these specific sites were evident among all species co-existing with the pathogen. In the laboratory, we experimentally inoculated Australian tree frogs with Bd to test how each binding pocket conformation influences disease resistance. Only the conformation of MHC-II pocket 9 of surviving subjects matched those of Bd-resistant species. This MHC-II conformation thus may determine amphibian resistance to Bd, although other MHC-II binding pockets also may contribute to resistance. Rescuing amphibian biodiversity will depend on our understanding of amphibian immune defence mechanisms against Bd. The identification of adaptive genetic markers for Bd resistance represents an important step forward towards that goal.

  17. High-throughput engineering and analysis of peptide binding to class II MHC

    PubMed Central

    Jiang, Wei; Boder, Eric T.

    2010-01-01

    Class II major histocompatibility complex (MHC-II) proteins govern stimulation of adaptive immunity by presenting antigenic peptides to CD4+ T lymphocytes. Many allelic variants of MHC-II exist with implications in peptide presentation and immunity; thus, high-throughput experimental tools for rapid and quantitative analysis of peptide binding to MHC-II are needed. Here, we present an expression system wherein peptide and MHC-II are codisplayed on the surface of yeast in an intracellular association-dependent manner and assayed by flow cytometry. Accordingly, the relative binding of different peptides and/or MHC-II variants can be assayed by genetically manipulating either partner, enabling the application of directed evolution approaches for high-throughput characterization or engineering. We demonstrate the application of this tool to map the side-chain preference for peptides binding to HLA-DR1 and to evolve novel HLA-DR1 mutants with altered peptide-binding specificity. PMID:20622157

  18. Negative Potentials Across Biological Membranes Promote Fusion by Class II and Class III Viral Proteins

    PubMed Central

    Markosyan, Ruben M.

    2010-01-01

    Voltage was investigated as a factor in the fusion of virions. Virions, pseudotyped with a class II, SFV E1 or VEEV E, or a class III protein, VSV G, were prepared with GFP within the core and a fluorescent lipid. This allowed both hemifusion and fusion to be monitored. Voltage clamping the target cell showed that fusion is promoted by a negative potential and hindered by a positive potential. Hemifusion occurred independent of polarity. Lipid dye movement, in the absence of content mixing, ceased before complete transfer for positive potentials, indicating that reversion of hemifused membranes into two distinct membranes is responsible for voltage dependence and inhibition of fusion. Content mixing quickly followed lipid dye transfer for a negative potential, providing a direct demonstration that hemifusion induced by class II and class III viral proteins is a functional intermediate of fusion. In the hemifused state, virions that fused exhibited slower lipid transfer than did nonfusing virions. All viruses with class II or III fusion proteins may utilize voltage to achieve infection. PMID:20427575

  19. 25 CFR 522.5 - Disapproval of a class II ordinance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Disapproval of a class II ordinance. 522.5 Section 522.5 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.5 Disapproval of a class II...

  20. Evaluation of arch width among Class I normal occlusion, Class II Division 1, Class II Division 2, and Class III malocclusion in Indian population.

    PubMed

    Patel, Dolly; Mehta, Falguni; Patel, Nimesh; Mehta, Nishit; Trivedi, Ipist; Mehta, Apexa

    2015-09-01

    To test the hypothesis that there is no difference between Class I (CI) normal occlusion, Class II division 1 (CIId1) and CII division 2 (CIId2), and Class III (CIII) malocclusion with respect to arch widths, width of the maxillary and mandibular arches, gender dimorphism within groups, and gender comparisons. Samples of 40 CI subjects, 40 CIId1 subjects, 40 CIId2 subjects, and 34 CIII subjects were studied. All subjects were Indians with no history of orthodontic treatment. An analysis of variance and Duncan's test statistically compared the groups and genders. CIId1 malocclusion showed the narrowest maxillary arch compared with the other types of malocclusions. CIII malocclusion showed largest mandibular arch than other types of malocclusions. Gender dimorphism is more commonly seen in CI normal occlusion than other types of malocclusions. Gender dimorphism is not observed in CIId1 group. Gender comparisons revealed arch width differences between different types of malocclusions more pronounced in males than in females. The maxillary/mandibular intermolar width difference is positive for CI normal occlusion and negative for CIId1, CIId2, and CIII malocclusions, which suggested, the presence of crossbite tendency in CII and CIII malocclusions. The hypothesis is rejected by the findings of this study.

  1. Improved Transgenic Mouse Model for Studying HLA Class I Antigen Presentation

    PubMed Central

    Huang, Man; Zhang, Wei; Guo, Jie; Wei, Xundong; Phiwpan, Krung; Zhang, Jianhua; Zhou, Xuyu

    2016-01-01

    HLA class I (HLA-I) transgenic mice have proven to be useful models for studying human MHC-related immune responses over the last two decades. However, differences in the processing and presentation machinery between humans and mice may have profound effects on HLA-I restricted antigen presentation. In this study, we generated a novel human TAP-LMP (hTAP-LMP) gene cluster transgenic mouse model carrying an intact human TAP complex and two human immunoproteasome LMP subunits, PSMB8/PSMB9. By crossing the hTAP-LMP strain with different HLA-I transgenic mice, we found that the expression levels of human HLA-I molecules, especially the A3 supertype members (e.g., A11 and A33), were remarkably enhanced in corresponding HLA-I/hTAP-LMP transgenic mice. Moreover, we found that humanized processing and presentation machinery increased antigen presentation of HLA-A11-restricted epitopes and promoted the rapid reduction of hepatitis B virus (HBV) infection in HLA-A11/hTAP-LMP mice. Together, our study highlights that HLA-I/hTAP-LMP mice are an improved model for studying antigen presentation of HLA-I molecules and their related CTL responses. PMID:27634283

  2. Defective MHC class II expression in an MHC class II deficiency patient is caused by a novel deletion of a splice donor site in the MHC class II transactivator gene.

    PubMed

    Peijnenburg, A; Van den Berg, R; Van Eggermond, M J; Sanal, O; Vossen, J M; Lennon, A M; Alcaïde-Loridan, C; Van den Elsen, P J

    2000-01-01

    MHC class II deficiency patients are mutated for transcription factors that regulate the expression of major histocompatibility complex (MHC) class II genes. Four complementation groups (A-D) are defined and the gene defective in group A has been shown to encode the MHC class II transactivator (CIITA). Here, we report the molecular characterization of a new MHC class II deficiency patient, ATU. Cell fusion experiments indicated that ATU belongs to complementation group A. Subsequent mutation analysis revealed that the CIITA mRNA lacked 84 nucleotides. This deletion was the result of the absence of a splice donor site in the CIITA gene of ATU. As a result of this novel homozygous genomic deletion, ATU CIITA failed to transactivate MHC class II genes. Furthermore, this truncated CIITA of ATU did not display a dominant negative effect on CIITA-mediated transactivation of various isotypic MHC class II promoters.

  3. Mutant MHC class II epitopes drive therapeutic immune responses to cancer

    PubMed Central

    Kreiter, Sebastian; Vormehr, Mathias; van de Roemer, Niels; Diken, Mustafa; Löwer, Martin; Diekmann, Jan; Boegel, Sebastian; Schrörs, Barbara; Vascotto, Fulvia; Castle, John C.; Tadmor, Arbel D.; Schoenberger, Stephen P.; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

    2016-01-01

    Tumour-specific mutations are ideal targets for cancer immunotherapy as they lack expression in healthy tissues and can potentially be recognized as neo-antigens by the mature T-cell repertoire. Their systematic targeting by vaccine approaches, however, has been hampered by the fact that every patient’s tumour possesses a unique set of mutations (‘the mutanome’) that must first be identified. Recently, we proposed a personalized immunotherapy approach to target the full spectrum of a patient’s individual tumour-specific mutations1. Here we show in three independent murine tumour models that a considerable fraction of non-synonymous cancer mutations is immunogenic and that, unexpectedly, the majority of the immunogenic mutanome is recognized by CD4+ T cells. Vaccination with such CD4+ immunogenic mutations confers strong antitumour activity. Encouraged by these findings, we established a process by which mutations identified by exome sequencing could be selected as vaccine targets solely through bioinformatic prioritization on the basis of their expression levels and major histocompatibility complex (MHC) class II-binding capacity for rapid production as synthetic poly-neo-epitope messenger RNA vaccines. We show that vaccination with such polytope mRNA vaccines induces potent tumour control and complete rejection of established aggressively growing tumours in mice. Moreover, we demonstrate that CD4+ T cell neo-epitope vaccination reshapes the tumour microenvironment and induces cytotoxic T lymphocyte responses against an independent immunodominant antigen in mice, indicating orchestration of antigen spread. Finally, we demonstrate an abundance of mutations predicted to bind to MHC class II in human cancers as well by employing the same predictive algorithm on corresponding human cancer types. Thus, the tailored immunotherapy approach introduced here may be regarded as a universally applicable blueprint for comprehensive exploitation of the substantial neo

  4. The shape and size of the sella turcica in skeletal Class I, Class II, and Class III Saudi subjects.

    PubMed

    Alkofide, Eman A

    2007-10-01

    The purpose of this study was to describe the shape and measure the size of the sella turcica in Saudi subjects with different skeletal types. Lateral cephalometric radiographs of 180 individuals (90 males and 90 females) with an age range of 11-26 years were taken and distributed according to skeletal classification; 60 Class I, 60 Class II, and 60 Class III. The sella turcica on each radiograph was analysed and measured to determine the shape of the sella, in addition to the linear dimensions of length, depth, and diameter. A Student's t-test was used to calculate differences in linear dimensions, while a one-way analysis of variance was performed to study the relationship between skeletal type and sella size. The results show that the sella turcica presented with a normal morphology in the majority of subjects (67 per cent). No significant differences in linear dimensions between genders could be found. When age was evaluated, significant differences were found between the older (15 years or more) and the younger (11-14 years) age groups at the 0.01 and 0.001 levels for length, depth, and diameter. Sella size of the older age group was larger than in the younger age group. When skeletal type was compared with sella size, a significant difference was found in the diameter of sella between the Class II and Class III subjects (P < 0.01). Larger diameter values were present in the skeletal Class III subjects, while smaller diameter sizes were apparent in Class II subjects (multiple comparison tests). When gender, age, and skeletal type were all compared with the size of the sella (regression analyses), age was significantly related to a change of length (P < 0.01) and diameter (P < 0.001). Sella shape and dimensions reported in the current study can be used as reference standards for further investigations involving the sella turcica area in Saudi subjects.

  5. Classification and treatment of Class II subdivision malocclusions.

    PubMed

    Cassidy, Sara E; Jackson, Stona R; Turpin, David L; Ramsay, Douglas S; Spiekerman, Charles; Huang, Greg J

    2014-04-01

    Patients with Class II subdivision malocclusions are a challenge for clinicians because reestablishing symmetry in 1 arch or both arches is often a treatment goal. In patients with mandibular skeletal asymmetry, surgery is often a treatment option. However, patients may be unwilling to undergo surgery, and other options might have to be considered. The aim of this study was to evaluate the etiologies and outcomes of Class II subdivision patients treated at the University of Washington graduate orthodontic clinic in Seattle from 1995 through 2011. A search of patients treated between 1995 and 2011 resulted in the identification of 110 consecutively treated Class II subdivision subjects with complete records. Ninety-eight subjects could be classified into 1 of 3 groups, based on midline position and dental or skeletal etiology. Initial and final models were used to measure the peer assessment rating scores, midlines, overjet, overbite, and molar positions. Initial and final cephalograms were traced and measured. Charts were reviewed for information regarding treatment. Twenty-five percent of the 98 subjects had their maxillary and mandibular midlines coincident with the facial midline; their asymmetries were due to a maxillary posterior dental asymmetry. Another 15% had maxillary midlines deviated from their facial midlines, caused by maxillary anterior and posterior dental asymmetry. About 50% of the subjects had mandibular midlines that were not coincident with their facial midlines, and most of them exhibited some degree of mandibular skeletal asymmetry. Over the past 15 years, treatment strategies used at the University of Washington indicated trends toward less surgery, fewer extractions, less use of headgear, and more reliance on fixed functional appliances. Ideal correction of midlines was not always achieved, especially in patients with mandibular skeletal asymmetry, with undercorrection occurring more commonly than overcorrection. Final peer assessment

  6. Oxidation matters: the ubiquitin proteasome system connects innate immune mechanisms with MHC class I antigen presentation.

    PubMed

    Warnatsch, Annika; Bergann, Theresa; Krüger, Elke

    2013-09-01

    During innate immune responses the delicate balance of protein synthesis, quality control and degradation is severely challenged by production of radicals and/or the massive synthesis of pathogen proteins. The regulated degradation of ubiquitin-tagged proteins by the ubiquitin proteasome system (UPS) represents one major pathway for the maintenance of cellular proteostasis and regulatory processes under these conditions. In addition, MHC class I antigen presentation is strictly dependent on an appropriate peptide supply by the UPS to efficiently prime CD8(+) T cells and to initiate an adaptive immune response. We here discuss recent efforts in defining the link between innate immune mechanisms like cytokine and ROS production, the induction of an efficient adaptive immune response and the specific involvement of the UPS therein. Cytokines and/or infections induce translation and the production of free radicals, which in turn confer oxidative damage to nascent as well as folded proteins. In parallel, the same signaling cascades are able to accelerate the protein turnover by the concomitantly induced ubiquitin conjugation and degradation of such damaged polypeptides by immunoproteasomes. The ability of immunoproteasomes to efficiently degrade such oxidant-damaged ubiquitylated proteins protects cells from accumulating toxic ubiquitin-rich aggregates. At the same time, this innate immune mechanism facilitates a sufficient peptide supply for MHC class I antigen presentation and connects it to initiation of adaptive immunity.

  7. MHC Class II haplotypes of Colombian Amerindian tribes

    PubMed Central

    Yunis, Juan J.; Yunis, Edmond J.; Yunis, Emilio

    2013-01-01

    We analyzed 1041 individuals belonging to 17 Amerindian tribes of Colombia, Chimila, Bari and Tunebo (Chibcha linguistic family), Embera, Waunana (Choco linguistic family), Puinave and Nukak (Maku-Puinave linguistic families), Cubeo, Guanano, Tucano, Desano and Piratapuyo (Tukano linguistic family), Guahibo and Guayabero (Guayabero Linguistic Family), Curripaco and Piapoco (Arawak linguistic family) and Yucpa (Karib linguistic family). for MHC class II haplotypes (HLA-DRB1, DQA1, DQB1). Approximately 90% of the MHC class II haplotypes found among these tribes are haplotypes frequently encountered in other Amerindian tribes. Nonetheless, striking differences were observed among Chibcha and non-Chibcha speaking tribes. The DRB1*04:04, DRB1*04:11, DRB1*09:01 carrying haplotypes were frequently found among non-Chibcha speaking tribes, while the DRB1*04:07 haplotype showed significant frequencies among Chibcha speaking tribes, and only marginal frequencies among non-Chibcha speaking tribes. Our results suggest that the differences in MHC class II haplotype frequency found among Chibcha and non-Chibcha speaking tribes could be due to genetic differentiation in Mesoamerica of the ancestral Amerindian population into Chibcha and non-Chibcha speaking populations before they entered into South America. PMID:23885196

  8. MHC Class II haplotypes of Colombian Amerindian tribes.

    PubMed

    Yunis, Juan J; Yunis, Edmond J; Yunis, Emilio

    2013-07-01

    We analyzed 1041 individuals belonging to 17 Amerindian tribes of Colombia, Chimila, Bari and Tunebo (Chibcha linguistic family), Embera, Waunana (Choco linguistic family), Puinave and Nukak (Maku-Puinave linguistic families), Cubeo, Guanano, Tucano, Desano and Piratapuyo (Tukano linguistic family), Guahibo and Guayabero (Guayabero Linguistic Family), Curripaco and Piapoco (Arawak linguistic family) and Yucpa (Karib linguistic family). for MHC class II haplotypes (HLA-DRB1, DQA1, DQB1). Approximately 90% of the MHC class II haplotypes found among these tribes are haplotypes frequently encountered in other Amerindian tribes. Nonetheless, striking differences were observed among Chibcha and non-Chibcha speaking tribes. The DRB1*04:04, DRB1*04:11, DRB1*09:01 carrying haplotypes were frequently found among non-Chibcha speaking tribes, while the DRB1*04:07 haplotype showed significant frequencies among Chibcha speaking tribes, and only marginal frequencies among non-Chibcha speaking tribes. Our results suggest that the differences in MHC class II haplotype frequency found among Chibcha and non-Chibcha speaking tribes could be due to genetic differentiation in Mesoamerica of the ancestral Amerindian population into Chibcha and non-Chibcha speaking populations before they entered into South America.

  9. Remarkably low affinity of CD4/peptide-major histocompatibility complex class II protein interactions

    PubMed Central

    Jönsson, Peter; Southcombe, Jennifer H.; Santos, Ana Mafalda; Huo, Jiandong; Fernandes, Ricardo A.; McColl, James; Lever, Melissa; Evans, Edward J.; Hudson, Alexander; Chang, Veronica T.; Hanke, Tomáš; Godkin, Andrew; Dunne, Paul D.; Horrocks, Mathew H.; Palayret, Matthieu; Screaton, Gavin R.; Petersen, Jan; Rossjohn, Jamie; Fugger, Lars; Dushek, Omer; Xu, Xiao-Ning; Davis, Simon J.; Klenerman, David

    2016-01-01

    The αβ T-cell coreceptor CD4 enhances immune responses more than 1 million-fold in some assays, and yet the affinity of CD4 for its ligand, peptide-major histocompatibility class II (pMHC II) on antigen-presenting cells, is so weak that it was previously unquantifiable. Here, we report that a soluble form of CD4 failed to bind detectably to pMHC II in surface plasmon resonance-based assays, establishing a new upper limit for the solution affinity at 2.5 mM. However, when presented multivalently on magnetic beads, soluble CD4 bound pMHC II-expressing B cells, confirming that it is active and allowing mapping of the native coreceptor binding site on pMHC II. Whereas binding was undetectable in solution, the affinity of the CD4/pMHC II interaction could be measured in 2D using CD4- and adhesion molecule-functionalized, supported lipid bilayers, yielding a 2D Kd of ∼5,000 molecules/μm2. This value is two to three orders of magnitude higher than previously measured 2D Kd values for interacting leukocyte surface proteins. Calculations indicated, however, that CD4/pMHC II binding would increase rates of T-cell receptor (TCR) complex phosphorylation by threefold via the recruitment of Lck, with only a small, 2–20% increase in the effective affinity of the TCR for pMHC II. The affinity of CD4/pMHC II therefore seems to be set at a value that increases T-cell sensitivity by enhancing phosphorylation, without compromising ligand discrimination. PMID:27114505

  10. A comparison of weight histories in women with class III vs. class I-II obesity.

    PubMed

    Crerand, Canice E; Wadden, Thomas A; Sarwer, David B; Fabricatore, Anthony N; Kuehnel, Robert H; Gibbons, Lauren M; Brock, Johanna R; Williams, Noel N

    2006-03-01

    To describe the weight histories of women with extreme or class III obesity (BMI >or= 40 kg/m(2)) in comparison with a sample of women with class I-II obesity (BMI < 40 kg/m(2)) and to provide reliability data for a clinical instrument that assesses weight history. Female patients (N = 149) with extreme obesity seeking bariatric surgery and 90 class I-II obese women seeking behavioral treatment completed the Weight and Lifestyle Inventory (WALI), a self-report instrument that assesses age of onset of obesity, maximum weight at different ages, family weight history, and weight changes related to pregnancy. Test-retest reliability data were obtained by administering the WALI to a subsample (n = 58) of class I-II obese participants at their initial visit and at another pretreatment visit 1 to 2 weeks later. Patients with extreme obesity had a significantly younger age of onset of obesity, were significantly heavier at all age ranges, reported significantly more weight gain with their first pregnancy, and had significantly heavier parents and siblings as compared with less obese patients. There were no significant differences between groups with respect to weight gain during second pregnancies or postpartum weight retention. Robust test-retest correlations were obtained for the weight history items on the WALI. Patients with extreme obesity report more indicators of a genetic predisposition to obesity as compared with less obese patients. The WALI appears to be a reliable instrument for the assessment of weight history in obese patients.

  11. Molecular characterization of MHC class II region in guinea fowl.

    PubMed

    Singh, S K; Mathew, J; Gupta, J; Mehra, S; Goyal, G; Sharma, D

    2010-12-01

    1. The MHC class II gene was amplified, cloned and sequenced in guinea fowl. 2. The NumeMHC II sequence of 754 nucleotides included complete exon 1 (91 nt), exon 2 (270 nt), exon 3 (282 nt) and exon 4 (110 nt). 3. The size of β(1) and β(2), domains were 89 and 93 amino acids, respectively in guinea fowl. 4. High amino acid variability (38·2%) was observed within guinea fowl in β(1) domain, while in β(2) domain, amino acid variability (6·3%) was low. 5. Among poultry species, the percent amino acid identity between guinea fowl and chicken, quail, pheasant and duck was 38·8, 42·2, 44·4 and 58·8 in β(1) domain; and 13·8, 17·0, 13·8 and 27·6 in β(2) domain, respectively. 6. Sequence alignment with mammalian and avian MHC showed that many of the conserved features of MHC class II glycoprotein was conserved in guinea fowl. 7. Within-species genetic distances (Poisson correction) based on cumulative amino acid variability in β(1) domain and β(2) domains was 0·141 in guinea fowl. 8. Guinea fowl showed low and similar genetic distances with all the poultry species (0·255-0·268) except duck (0·456). 9. Guinea fowl made separate branch within the major cluster having chicken, quail and pheasant, showing equal distance from these poultry species, whereas duck MHC II clustered separately.

  12. Anti-coreceptor antibodies profoundly affect staining with peptide-MHC class I and class II tetramers.

    PubMed

    Wooldridge, Linda; Scriba, Thomas J; Milicic, Anita; Laugel, Bruno; Gostick, Emma; Price, David A; Phillips, Rodney E; Sewell, Andrew K

    2006-07-01

    The T cell coreceptors CD8 and CD4 bind to invariable regions of peptide-MHC class I (pMHCI) and class II (pMHCII) molecules, respectively, and facilitate antigen recognition by a number of mechanisms. It is established that some antibodies (Ab) specific for the CD8 molecule, which stabilizes TCR/pMHCI interactions, can alter the binding of pMHCI tetramers to cell surface TCR. In contrast, the extremely weak pMHCII/CD4 interaction does not stabilize TCR/pMHCII interactions or contribute to cognate tetramer binding; consequently, it is assumed that anti-CD4 Ab do not affect pMHCII binding. Here, we used a panel of point-mutated HLA A2 molecules with a range of affinities for CD8 spanning over three orders of magnitude to demonstrate that anti-CD8 Ab-mediated inhibition of pMHCI tetramer binding and cognate T cell activation correlates directly with the strength of the pMHCI/CD8 interaction. Further, some anti-CD4 Ab were found to block pMHCII tetramer binding; these effects were also paralleled in T cell activation assays. In sum, these data challenge the assertion that anti-coreceptor Ab exert their effects on T cell activation and pMHC binding solely by blocking pMHC/coreceptor interactions.

  13. MHC class II up-regulation and co-localization with Fas in experimental models of immune-mediated bone marrow failure

    PubMed Central

    Erie, Andrew J.; Samsel, Leigh; Takaku, Tomoiku; Desierto, Marie J.; Keyvanfar, Keyvan; McCoy, J. Philip; Young, Neal S.; Chen, Jichun

    2011-01-01

    Objective To test the hypothesis that gamma interferon (IFN-γ) promotes MHC class II expression on bone marrow (BM) cell targets that facilitates T cell-mediated BM destruction in immune-mediated BM failure. Materials and Methods Allogeneic lymph node (LN) cells were infused into MHC or minor histocompatibility antigen (minor-H) mismatched hosts to induce BM failure. MHC class II and Fas expression and cell apoptosis were analyzed by flow cytometry. MHC class II-Fas co-localization was detected by ImageStream Imaging Flow Cytometry and other cell-cell associations were visualized by confocal microscopy. T cell-mediated BM cell apoptosis and effects of IFN-γ on MHC class II-Fas co-localization on normal BM cells were studied using cell culture in vitro followed by conventional and imaging flow cytometry. Results BM failure animals had significantly up-regulated MHC class II expression on CD4−CD8−CD11b−CD45R− residual BM cells and significantly increased MHC class II-Fas co-localization on BM CD150+ and CD34+ hematopoietic cells. MHC class II+Fas+ BM cells were closely associated with CD4+ T cells in the BM of affected animals, and they were significantly more responsive to T-cell mediated cell apoptosis relative to MHC class II−Fas− BM cells. Infusion of IFN-γ-deficient LN cells into minor-H mismatched recipients resulted in no MHC class II-Fas up-regulation and no clinically overt BM failure. Treatment with recombinant IFN-γ significantly increased both MHC class II-Fas co-expression and co-localization on normal BM cells. Conclusion Elevation of the inflammatory cytokine IFN-γ stimulated MHC class II expression and MHC class II-Fas co-localization, which may facilitate T-cell mediated cell destruction. PMID:21635935

  14. Spectral energy distribution analysis of class I and class II FU Orionis stars

    SciTech Connect

    Gramajo, Luciana V.; Gómez, Mercedes; Rodón, Javier A. E-mail: mercedes@oac.uncor.edu

    2014-06-01

    FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ∼80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ∼10{sup –7} M {sub ☉} yr{sup –1} versus ∼10{sup –5} M {sub ☉} yr{sup –1} for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (∼70%) have envelope mass accretion rates above 10{sup –7} M {sub ☉} yr{sup –1}. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.

  15. Simultaneous Observation of Water and Class I Methanol Masers toward Class II Methanol Maser Sources

    NASA Astrophysics Data System (ADS)

    Kang, Hyunwoo; Kim, Kee-Tae; Byun, Do-Young; Lee, Seokho; Park, Yong-Sun

    2015-11-01

    We present a simultaneous single-dish survey of 22 GHz water masers and 44 and 95 GHz class I methanol masers toward 77 6.7 GHz class II methanol maser sources, which were selected from the Arecibo methanol maser Galactic plane survey catalog. Water maser emission is detected in 39 (51%) sources, 15 of which are new detections. Methanol maser emission at 44 and 95 GHz is found in 25 (32%) and 19 (25%) sources, 21 and 13 of which, respectively, are newly detected. We find four high-velocity (>30 km s-1) water maser sources, including three dominant blue- or redshifted outflows. The 95 GHz masers always appear with 44 GHz maser emission. They are strongly correlated with 44 GHz masers in velocity, flux density, and luminosity, yet they are not correlated with either water or 6.7 GHz class II methanol masers. The average peak flux density ratio of 95 GHz masers to 44 GHz masers is close to unity, which is two times higher than previous estimates. The flux densities of class I methanol masers are more closely correlated with the associated Bolocam Galactic Plane Survey core mass than those of water masers or class II methanol masers. Using the large velocity gradient model and assuming unsaturated class I methanol maser emission, we derive the fractional abundance of methanol to be in the range 4.2 × 10-8-2.3 × 10-6, with a median value of 3.3 ± 2.7 × 10-7.

  16. Spectral Energy Distribution Analysis of Class I and Class II FU Orionis Stars

    NASA Astrophysics Data System (ADS)

    Gramajo, Luciana V.; Rodón, Javier A.; Gómez, Mercedes

    2014-06-01

    FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ~80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ~10-7 M ⊙ yr-1 versus ~10-5 M ⊙ yr-1 for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (~70%) have envelope mass accretion rates above 10-7 M ⊙ yr-1. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.

  17. Genetic origin of the Swedish Sami inferred from HLA class I and class II allele frequencies.

    PubMed

    Johansson, Asa; Ingman, Max; Mack, Steven J; Erlich, Henry; Gyllensten, Ulf

    2008-11-01

    Sami of northern Scandinavia are genetic outliers among European populations and their origin has been difficult to determine. In order to study the genetic origin of the Swedish Sami, we have performed high-resolution typing of the class I HLA-A and -B loci and the class II DRB1, DQB1 and DQA1 loci in the northern and southern Swedish Sami. Several of the common class I alleles in Sami (B*0702, B*1501, B*4002 and A*0301) are found at high frequency in other European populations. However, a number of class I and class II alleles (B*4001, A*2402, DRB1*0901 and DRB1*1101) in the Swedish Sami are characteristic of Asian populations. Admixture analyses indicate that 87% of the Sami gene pool is of European origin and that the Asian contribution is 13%. Our HLA analyses indicate a higher proportion of Asian ancestry in the Sami than shown by previous genetic studies.

  18. Comparison of soft tissue facial morphometry in children with Class I and Class II occlusions.

    PubMed

    Ferrario, V F; Sforza, C; Serrao, G; Puletto, S; Bignotto, M; Tartaglia, G

    1994-01-01

    Three-dimensional soft tissue facial morphometry was investigated in a sample of 167 children aged 6 to 9 years by using a new noninvasive computerized method. For each child, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared CCD cameras, real-time hardware for the recognition of markers, and software for the three-dimensional reconstruction of the x, y, and z coordinates of landmarks. From these landmarks, 15 linear and 10 angular measurements and five linear distance ratios were computed. For each age class, mean values were computed for all children with a bilateral Angle Class I occlusion (modified according to Katz) and compared with values obtained in children with a bilateral Class II occlusion. Most of the differences involved three-dimensional angular measurements: Class II children had more convex faces in the sagittal plane and a less prominent mandible than did Class I children. No differences were found in the linear measurements. Only the lower facial height ratio was different between the two occlusion groups, but the difference was not consistent among all the age groups.

  19. HLA non-class II genes may confer type I diabetes susceptibility in a Mapuche (Amerindian) affected family.

    PubMed

    Pérez-Bravo, Francisco; Martinez-Laso, Jorge; Martin-Villa, Jose M; Moscoso, Juan; Moreno, Almudena; Serrano-Vela, Juan I; Zamora, Jorge; Asenjo, Silvia; Gleisner, Andrea; Arnaiz-Villena, Antonio

    2006-01-01

    A rare case of type I diabetes is studied in an Amerindian (Mapuche) family from Chile, analyzing glutamic acid decarboxylase, islet-cell autoantibodies and human leukocyte antigen (HLA) genes. The affected sib is the only one that has one specific HLA haplotype combination that differs from the other sibs only in the HLA class I genes. It is concluded that HLA diabetes susceptibility factors may be placed outside the class II region or even that susceptibility factors do not exist in the HLA region in this Amerindian family.

  20. Functional variation of the antigen I/II surface protein in Streptococcus mutans and Streptococcus intermedius.

    PubMed

    Petersen, F C; Assev, S; van der Mei, H C; Busscher, H J; Scheie, A A

    2002-01-01

    Although Streptococcus intermedius and Streptococcus mutans are regarded as members of the commensal microflora of the body, S. intermedius is often associated with deep-seated purulent infections, whereas S. mutans is frequently associated with dental caries. In this study, we investigated the roles of the S. mutans and S. intermedius antigen I/II proteins in adhesion and modulation of cell surface characteristics. By using isogenic mutants, we show that the antigen I/II in S. mutans, but not in S. intermedius, was involved in adhesion to a salivary film under flowing conditions, as well as in binding to rat collagen type I. Binding to human fibronectin was a common function associated with the S. mutans and S. intermedius antigen I/II. Adhesion of S. mutans or S. intermedius to human collagen types I or IV was negligible. Hydrophobicity, as measured by water contact angles, and zeta potentials were unaltered in the S. intermedius mutant. The S. mutans isogenic mutants, on the other hand, exhibited more positive zeta potentials at physiological pH values than did the wild type. The results indicate common and species-specific roles for the antigen I/II in mediating the attachment of S. mutans and S. intermedius to host components and in determining cell surface properties.

  1. Pseudomonas aeruginosa Cif Protein Enhances the Ubiquitination and Proteasomal Degradation of the Transporter Associated with Antigen Processing (TAP) and Reduces Major Histocompatibility Complex (MHC) Class I Antigen Presentation*

    PubMed Central

    Bomberger, Jennifer M.; Ely, Kenneth H.; Bangia, Naveen; Ye, Siying; Green, Kathy A.; Green, William R.; Enelow, Richard I.; Stanton, Bruce A.

    2014-01-01

    Cif (PA2934), a bacterial virulence factor secreted in outer membrane vesicles by Pseudomonas aeruginosa, increases the ubiquitination and lysosomal degradation of some, but not all, plasma membrane ATP-binding cassette transporters (ABC), including the cystic fibrosis transmembrane conductance regulator and P-glycoprotein. The goal of this study was to determine whether Cif enhances the ubiquitination and degradation of the transporter associated with antigen processing (TAP1 and TAP2), members of the ABC transporter family that play an essential role in antigen presentation and intracellular pathogen clearance. Cif selectively increased the amount of ubiquitinated TAP1 and increased its degradation in the proteasome of human airway epithelial cells. This effect of Cif was mediated by reducing USP10 deubiquitinating activity, resulting in increased polyubiquitination and proteasomal degradation of TAP1. The reduction in TAP1 abundance decreased peptide antigen translocation into the endoplasmic reticulum, an effect that resulted in reduced antigen available to MHC class I molecules for presentation at the plasma membrane of airway epithelial cells and recognition by CD8+ T cells. Cif is the first bacterial factor identified that inhibits TAP function and MHC class I antigen presentation. PMID:24247241

  2. Pseudomonas aeruginosa Cif protein enhances the ubiquitination and proteasomal degradation of the transporter associated with antigen processing (TAP) and reduces major histocompatibility complex (MHC) class I antigen presentation.

    PubMed

    Bomberger, Jennifer M; Ely, Kenneth H; Bangia, Naveen; Ye, Siying; Green, Kathy A; Green, William R; Enelow, Richard I; Stanton, Bruce A

    2014-01-03

    Cif (PA2934), a bacterial virulence factor secreted in outer membrane vesicles by Pseudomonas aeruginosa, increases the ubiquitination and lysosomal degradation of some, but not all, plasma membrane ATP-binding cassette transporters (ABC), including the cystic fibrosis transmembrane conductance regulator and P-glycoprotein. The goal of this study was to determine whether Cif enhances the ubiquitination and degradation of the transporter associated with antigen processing (TAP1 and TAP2), members of the ABC transporter family that play an essential role in antigen presentation and intracellular pathogen clearance. Cif selectively increased the amount of ubiquitinated TAP1 and increased its degradation in the proteasome of human airway epithelial cells. This effect of Cif was mediated by reducing USP10 deubiquitinating activity, resulting in increased polyubiquitination and proteasomal degradation of TAP1. The reduction in TAP1 abundance decreased peptide antigen translocation into the endoplasmic reticulum, an effect that resulted in reduced antigen available to MHC class I molecules for presentation at the plasma membrane of airway epithelial cells and recognition by CD8(+) T cells. Cif is the first bacterial factor identified that inhibits TAP function and MHC class I antigen presentation.

  3. Accumulation of Major Histocompatibility Complex Class II Molecules in Mast Cell Secretory Granules and Their Release upon Degranulation

    PubMed Central

    Raposo, Graça; Tenza, Danielle; Mecheri, Salahedine; Peronet, Roger; Bonnerot, Christian; Desaymard, Catherine

    1997-01-01

    To investigate the relationship between major histocompatibility complex (MHC) class II compartments, secretory granules, and secretory lysosomes, we analyzed the localization and fate of MHC class II molecules in mast cells. In bone marrow-derived mast cells, the bulk of MHC class II molecules is contained in two distinct compartments, with features of both lysosomal compartments and secretory granules defined by their protein content and their accessibility to endocytic tracers. Type I granules display internal membrane vesicles and are accessed by exogenous molecules after a time lag of 20 min; type II granules are reached by the endocytic tracer later and possess a serotonin-rich electron-dense core surrounded by a multivesicular domain. In these type I and type II granules, MHC class II molecules, mannose-6-phosphate receptors and lysosomal membrane proteins (lamp1 and lamp2) localize to small intralumenal vesicles. These 60–80-nm vesicles are released along with inflammatory mediators during mast cell degranulation triggered by IgE-antigen complexes. These observations emphasize the intimate connection between the endocytic and secretory pathways in cells of the hematopoietic lineage which allows regulated secretion of the contents of secretory lysosomes, including membrane proteins associated with small vesicles. PMID:9398681

  4. Accumulation of major histocompatibility complex class II molecules in mast cell secretory granules and their release upon degranulation.

    PubMed

    Raposo, G; Tenza, D; Mecheri, S; Peronet, R; Bonnerot, C; Desaymard, C

    1997-12-01

    To investigate the relationship between major histocompatibility complex (MHC) class II compartments, secretory granules, and secretory lysosomes, we analyzed the localization and fate of MHC class II molecules in mast cells. In bone marrow-derived mast cells, the bulk of MHC class II molecules is contained in two distinct compartments, with features of both lysosomal compartments and secretory granules defined by their protein content and their accessibility to endocytic tracers. Type I granules display internal membrane vesicles and are accessed by exogenous molecules after a time lag of 20 min; type II granules are reached by the endocytic tracer later and possess a serotonin-rich electron-dense core surrounded by a multivesicular domain. In these type I and type II granules, MHC class II molecules, mannose-6-phosphate receptors and lysosomal membrane proteins (lamp1 and lamp2) localize to small intralumenal vesicles. These 60-80-nm vesicles are released along with inflammatory mediators during mast cell degranulation triggered by IgE-antigen complexes. These observations emphasize the intimate connection between the endocytic and secretory pathways in cells of the hematopoietic lineage which allows regulated secretion of the contents of secretory lysosomes, including membrane proteins associated with small vesicles.

  5. Aberrant MHC class II expression in mouse joints leads to arthritis with extraarticular manifestations similar to rheumatoid arthritis

    PubMed Central

    Kanazawa, Satoshi; Ota, Shusuke; Sekine, Chiyoko; Tada, Toyohiro; Otsuka, Takanobu; Okamoto, Takashi; Sønderstrup, Grete; Peterlin, B. Matija

    2006-01-01

    Genetic susceptibility to rheumatoid arthritis (RA) is associated with certain MHC class II molecules. To clarify the role of these determinants in RA, we generated the D1CC transgenic mouse that expressed genes involved in antigen processing and presentation by the MHC class II pathway in joints. The class II transactivator, which was transcribed from the rat collagen type II promoter and enhancer, directed the expression of these genes. In D1CC mice congenic for the H-2q (DBA/1) background, small amounts of bovine collagen type II in adjuvant induced reproducibly an inflammatory arthritis resembling RA. Importantly, these stimuli had no effect in DBA/1 mice. Eighty-nine percent of D1CC mice developed chronic disease with joint swelling, redness, and heat in association with synovial proliferation as well as pannus formation and mononuclear infiltration of synovial membranes. Granulomatous lesions resembling rheumatoid nodules and interstitial pneumonitis also were observed. As in patients with RA, anticyclic citrullinated peptide antibodies were detected during the inflammatory stage. Finally, joints in D1CC mice displayed juxtaarticular demineralization, severe joint space narrowing, and erosions, which led to ankylosis, but without the appearance of osteophytes. Thus, aberrant expression of MHC class II in joints facilitates the development of severe erosive inflammatory polyarthritis, which is very similar to RA. PMID:16980409

  6. Natalizumab-related anaphylactoid reactions in MS patients are associated with HLA class II alleles

    PubMed Central

    de la Hera, Belén; Urcelay, Elena; Brassat, David; Chan, Andrew; Vidal-Jordana, Angela; Salmen, Anke; Villar, Luisa Maria; Álvarez-Cermeño, José Carlos; Izquierdo, Guillermo; Fernández, Oscar; Oliver, Begoña; Saiz, Albert; Ara, Jose Ramón; Vigo, Ana G.; Arroyo, Rafael; Meca, Virginia; Malhotra, Sunny; Fissolo, Nicolás; Horga, Alejandro; Montalban, Xavier

    2014-01-01

    Objectives: We aimed to investigate potential associations between human leukocyte antigen (HLA) class I and class II alleles and the development of anaphylactic/anaphylactoid reactions in patients with multiple sclerosis (MS) treated with natalizumab. Methods: HLA class I and II genotyping was performed in patients with MS who experienced anaphylactic/anaphylactoid reactions and in patients who did not develop infusion-related allergic reactions following natalizumab administration. Results: A total of 119 patients with MS from 3 different cohorts were included in the study: 54 with natalizumab-related anaphylactic/anaphylactoid reactions and 65 without allergic reactions. HLA-DRB1*13 and HLA-DRB1*14 alleles were significantly increased in patients who developed anaphylactic/anaphylactoid reactions (pM-H = 3 × 10−7; odds ratio [OR]M-H = 8.96, 95% confidence interval [CI] = 3.40–23.64), with a positive predictive value (PPV) of 82%. In contrast, the HLA-DRB1*15 allele was significantly more represented in patients who did not develop anaphylactic/anaphylactoid reactions to natalizumab (pM-H = 6 × 10−4; ORM-H = 0.2, 95% CI = 0.08–0.50), with a PPV of 81%. Conclusions: HLA-DRB1 genotyping before natalizumab treatment may help neurologists to identify patients with MS at risk for developing serious systemic hypersensitivity reactions associated with natalizumab administration. PMID:25520955

  7. HLA class II genes modulate vaccine-induced antibody responses to affect HIV-1 acquisition

    PubMed Central

    Prentice, Heather A.; Tomaras, Georgia D.; Geraghty, Daniel E.; Apps, Richard; Fong, Youyi; Ehrenberg, Philip K.; Rolland, Morgane; Kijak, Gustavo H.; Krebs, Shelly J.; Nelson, Wyatt; DeCamp, Allan; Shen, Xiaoying; Yates, Nicole L.; Zolla-Pazner, Susan; Nitayaphan, Sorachai; Rerks-Ngarm, Supachai; Kaewkungwal, Jaranit; Pitisuttithum, Punnee; Ferrari, Guido; Juliana McElrath, M.; Montefiori, David C.; Bailer, Robert T.; Koup, Richard A.; O’Connell, Robert J.; Robb, Merlin L.; Michael, Nelson L.; Gilbert, Peter B.; Kim, Jerome H.; Thomas, Rasmi

    2016-01-01

    In the RV144 vaccine trial, two antibody responses were found to correlate with HIV-1 acquisition. Because human leukocyte antigen (HLA) class II–restricted CD4+ T cells are involved in antibody production, we tested whether HLA class II genotypes affected HIV-1–specific antibody levels and HIV-1 acquisition in 760 individuals. Indeed, antibody responses correlated with acquisition only in the presence of single host HLA alleles. Envelope (Env)–specific immunoglobulin A (IgA) antibodies were associated with increased risk of acquisition specifically in individuals with DQB1*06. IgG antibody responses to Env amino acid positions 120 to 204 were higher and were associated with decreased risk of acquisition and increased vaccine efficacy only in the presence of DPB1*13. Screening IgG responses to overlapping peptides spanning Env 120–204 and viral sequence analysis of infected individuals defined differences in vaccine response that were associated with the presence of DPB1*13 and could be responsible for the protection observed. Overall, the underlying genetic findings indicate that HLA class II modulated the quantity, quality, and efficacy of antibody responses in the RV144 trial. PMID:26180102

  8. Decreased monocyte class II MHC expression following major abdominal surgery in children is related to operative stress.

    PubMed

    McHoney, M; Klein, N J; Eaton, S; Pierro, A

    2006-04-01

    Monocyte class II major histocompatibility complex (MHC) expression is necessary for antigen presentation and stimulation of T-cells. The aim of this study was to correlate monocyte class II MHC response to operative stress in children and the possible influence of cytokines in the postoperative period. We studied 21 children undergoing elective abdominal surgery. Operative stress score (OSS) was calculated. Monocyte class II MHC expression was measured preoperatively, immediately after surgery, 24 and 48 h postoperatively, using flow cytometry. Class II MHC is expressed as mean fluorescence intensity (MFI) of monocytes expressing MHC (mean +/- SD). Cytokine levels (interleukins 1ra, 6, and 10, and tumor necrosis factor-alpha) were also measured. Data between time points were compared using repeated measures ANOVA. There was an immediate postoperative decrease in class II MHC expression, with lowest levels 24 h postoperatively (preoperative 50 +/- 23.6, 24 h 18.2 +/- 9.4, P < 0.0001 vs. preoperative). At 48 h there was partial recovery in class II MHC, but levels were still significantly lower than preoperative (23.9 +/- 11.1, P < 0.001). The degree of monocyte depression was related to the magnitude of operative stress. Patients who had OSS <10 displayed some recovery in expression at 48 h 25.5 +/- 11.1), whereas in patients with OSS > or = 10 (severe surgical stress), expression further decreased at 48 h (MFI 14.0 +/- 0.1). There was an elevation of interleukin-1ra in the immediate postoperative period in both groups. There was no elevation in the other cytokines. Abdominal surgery in children decreases monocyte MHC expression. Class II MHC depression was related to magnitude of surgical trauma, implying that more severe immuneparesis follows surgery of greater magnitude. This may predispose to postoperative infection.

  9. Selection and trans-species polymorphism of major histocompatibility complex class II genes in the order Crocodylia.

    PubMed

    Jaratlerdsiri, Weerachai; Isberg, Sally R; Higgins, Damien P; Miles, Lee G; Gongora, Jaime

    2014-01-01

    Major Histocompatibility Complex (MHC) class II genes encode for molecules that aid in the presentation of antigens to helper T cells. MHC characterisation within and between major vertebrate taxa has shed light on the evolutionary mechanisms shaping the diversity within this genomic region, though little characterisation has been performed within the Order Crocodylia. Here we investigate the extent and effect of selective pressures and trans-species polymorphism on MHC class II α and β evolution among 20 extant species of Crocodylia. Selection detection analyses showed that diversifying selection influenced MHC class II β diversity, whilst diversity within MHC class II α is the result of strong purifying selection. Comparison of translated sequences between species revealed the presence of twelve trans-species polymorphisms, some of which appear to be specific to the genera Crocodylus and Caiman. Phylogenetic reconstruction clustered MHC class II α sequences into two major clades representing the families Crocodilidae and Alligatoridae. However, no further subdivision within these clades was evident and, based on the observation that most MHC class II α sequences shared the same trans-species polymorphisms, it is possible that they correspond to the same gene lineage across species. In contrast, phylogenetic analyses of MHC class II β sequences showed a mixture of subclades containing sequences from Crocodilidae and/or Alligatoridae, illustrating orthologous relationships among those genes. Interestingly, two of the subclades containing sequences from both Crocodilidae and Alligatoridae shared specific trans-species polymorphisms, suggesting that they may belong to ancient lineages pre-dating the divergence of these two families from the common ancestor 85-90 million years ago. The results presented herein provide an immunogenetic resource that may be used to further assess MHC diversity and functionality in Crocodylia.

  10. Selection and Trans-Species Polymorphism of Major Histocompatibility Complex Class II Genes in the Order Crocodylia

    PubMed Central

    Jaratlerdsiri, Weerachai; Isberg, Sally R.; Higgins, Damien P.; Miles, Lee G.; Gongora, Jaime

    2014-01-01

    Major Histocompatibility Complex (MHC) class II genes encode for molecules that aid in the presentation of antigens to helper T cells. MHC characterisation within and between major vertebrate taxa has shed light on the evolutionary mechanisms shaping the diversity within this genomic region, though little characterisation has been performed within the Order Crocodylia. Here we investigate the extent and effect of selective pressures and trans-species polymorphism on MHC class II α and β evolution among 20 extant species of Crocodylia. Selection detection analyses showed that diversifying selection influenced MHC class II β diversity, whilst diversity within MHC class II α is the result of strong purifying selection. Comparison of translated sequences between species revealed the presence of twelve trans-species polymorphisms, some of which appear to be specific to the genera Crocodylus and Caiman. Phylogenetic reconstruction clustered MHC class II α sequences into two major clades representing the families Crocodilidae and Alligatoridae. However, no further subdivision within these clades was evident and, based on the observation that most MHC class II α sequences shared the same trans-species polymorphisms, it is possible that they correspond to the same gene lineage across species. In contrast, phylogenetic analyses of MHC class II β sequences showed a mixture of subclades containing sequences from Crocodilidae and/or Alligatoridae, illustrating orthologous relationships among those genes. Interestingly, two of the subclades containing sequences from both Crocodilidae and Alligatoridae shared specific trans-species polymorphisms, suggesting that they may belong to ancient lineages pre-dating the divergence of these two families from the common ancestor 85–90 million years ago. The results presented herein provide an immunogenetic resource that may be used to further assess MHC diversity and functionality in Crocodylia. PMID:24503938

  11. Class II Division 1 in New Dimension: Role of Posterior Transverse Interarch Discrepancy in Class II Division 1 Malocclusion During the Mixed Dentition Period

    PubMed Central

    Garg, Deepanshu; Mahajan, Neeraj; Bansal, Samriti; Sawhney, Anshul; Kaur, Jasvir; Tripathi, Shashank; Malaviya, Neha

    2015-01-01

    Introduction Posterior transverse discrepancy as seen in some cases of Class II Division 1 malocclusion in mixed dentition period can be related to typical skeletofacial characteristics. These features when studied early in the mixed dentition period give a clear view of the desired appropriate treatment plan in a particular case. Aim The purpose of this study was to establish a simple method to determine the posterior (intermolar) transverse discrepancy and craniofacial skeletal features between the dental arches during the mixed dentition in a sample of Class II Division 1 patients to provide diagnostic and therapeutic guidance in the early approach. Materials and Methods A sample of 60 Class II Division 1 patients in mixed dention that were divided into 30 Class II Division 1 patients with posterior transverse interarch discrepancy {Class II (I) PTID group} and 30 Class II Division 1 patients without posterior transverse interarch discrepancy {Class II (I) NPTID group}. Thirty Class I subjects in mixed dentition were included as control. Results The skeletal features of the Class II group without PTID are those of the skeletal Class II associated with ‘anatomic’ mandibular retrusion (due to a micrognathic mandible) and those of the Class II group with PTID as skeletal Class II associated with only a ‘functional’ mandibular retrusion (due to a posteriorly displaced mandible of normal size). Conclusion This study confirmed the role of occlusion in the control of maxillomandibular skeletal relationships.The treatment strategies could be planned on the basis of the transverse component of Class II Division 1 groups in the mixed dentition period. PMID:26417555

  12. Islet cell hyperexpression of HLA class I antigens: a defining feature in type 1 diabetes

    PubMed Central

    Rodriguez-Calvo, Teresa; Gerling, Ivan C.; Mathews, Clayton E.; Kaddis, John S.; Russell, Mark A.; Zeissler, Marie; Leete, Pia; Krogvold, Lars; Dahl-Jørgensen, Knut; von Herrath, Matthias; Pugliese, Alberto; Atkinson, Mark A.

    2016-01-01

    Aims/hypothesis Human pancreatic beta cells may be complicit in their own demise in type 1 diabetes, but how this occurs remains unclear. One potentially contributing factor is hyperexpression of HLA class I antigens. This was first described approximately 30 years ago, but has never been fully characterised and was recently challenged as artefactual. Therefore, we investigated HLA class I expression at the protein and RNA levels in pancreases from three cohorts of patients with type 1 diabetes. The principal aims were to consider whether HLA class I hyperexpression is artefactual and, if not, to determine the factors driving it. Methods Pancreas samples from type 1 diabetes patients with residual insulin-containing islets (n = 26) from the Network for Pancreatic Organ donors with Diabetes (nPOD), Diabetes Virus Detection study (DiViD) and UK recent-onset type 1 diabetes collections were immunostained for HLA class I isoforms, signal transducer and activator of transcription 1 (STAT1), NLR family CARD domain containing 5 (NLRC5) and islet hormones. RNA was extracted from islets isolated by laser-capture microdissection from nPOD and DiViD samples and analysed using gene-expression arrays. Results Hyperexpression of HLA class I was observed in the insulin-containing islets of type 1 diabetes patients from all three tissue collections, and was confirmed at both the RNA and protein levels. The expression of β2-microglobulin (a second component required for the generation of functional HLA class I complexes) was also elevated. Both ‘classical’ HLA class I isoforms (i.e. HLA-ABC) as well as a ‘non-classical’ HLA molecule, HLA-F, were hyperexpressed in insulin-containing islets. This hyperexpression did not correlate with detectable upregulation of the transcriptional regulator NLRC5. However, it was strongly associated with increased STAT1 expression in all three cohorts. Islet hyperexpression of HLA class I molecules occurred in the insulin-containing islets

  13. Islet cell hyperexpression of HLA class I antigens: a defining feature in type 1 diabetes.

    PubMed

    Richardson, Sarah J; Rodriguez-Calvo, Teresa; Gerling, Ivan C; Mathews, Clayton E; Kaddis, John S; Russell, Mark A; Zeissler, Marie; Leete, Pia; Krogvold, Lars; Dahl-Jørgensen, Knut; von Herrath, Matthias; Pugliese, Alberto; Atkinson, Mark A; Morgan, Noel G

    2016-11-01

    Human pancreatic beta cells may be complicit in their own demise in type 1 diabetes, but how this occurs remains unclear. One potentially contributing factor is hyperexpression of HLA class I antigens. This was first described approximately 30 years ago, but has never been fully characterised and was recently challenged as artefactual. Therefore, we investigated HLA class I expression at the protein and RNA levels in pancreases from three cohorts of patients with type 1 diabetes. The principal aims were to consider whether HLA class I hyperexpression is artefactual and, if not, to determine the factors driving it. Pancreas samples from type 1 diabetes patients with residual insulin-containing islets (n = 26) from the Network for Pancreatic Organ donors with Diabetes (nPOD), Diabetes Virus Detection study (DiViD) and UK recent-onset type 1 diabetes collections were immunostained for HLA class I isoforms, signal transducer and activator of transcription 1 (STAT1), NLR family CARD domain containing 5 (NLRC5) and islet hormones. RNA was extracted from islets isolated by laser-capture microdissection from nPOD and DiViD samples and analysed using gene-expression arrays. Hyperexpression of HLA class I was observed in the insulin-containing islets of type 1 diabetes patients from all three tissue collections, and was confirmed at both the RNA and protein levels. The expression of β2-microglobulin (a second component required for the generation of functional HLA class I complexes) was also elevated. Both 'classical' HLA class I isoforms (i.e. HLA-ABC) as well as a 'non-classical' HLA molecule, HLA-F, were hyperexpressed in insulin-containing islets. This hyperexpression did not correlate with detectable upregulation of the transcriptional regulator NLRC5. However, it was strongly associated with increased STAT1 expression in all three cohorts. Islet hyperexpression of HLA class I molecules occurred in the insulin-containing islets of patients with recent-onset type 1

  14. Development of a simultaneous high resolution typing method for three SLA class II genes, SLA-DQA, SLA-DQB1, and SLA-DRB1 and the analysis of SLA class II haplotypes.

    PubMed

    Le, MinhThong; Choi, Hojun; Choi, Min-Kyeung; Cho, Hyesun; Kim, Jin-Hoi; Seo, Han Geuk; Cha, Se-Yeon; Seo, Kunho; Dadi, Hailu; Park, Chankyu

    2015-06-15

    The characterization of the genetic variations of major histocompatibility complex (MHC) is essential to understand the relationship between the genetic diversity of MHC molecules and disease resistance and susceptibility in adaptive immunity. We previously reported the development of high-resolution individual locus typing methods for three of the most polymorphic swine leukocyte antigens (SLA) class II loci, namely, SLA-DQA, SLA-DQB1, and SLA-DRB1. In this study, we extensively modified our previous protocols and developed a method for the simultaneous amplification of the three SLA class II genes and subsequent analysis of individual loci using direct sequencing. The unbiased and simultaneous amplification of alleles from the all three hyper-polymorphic and pseudogene containing genes such as MHC genes is extremely challenging. However, using this method, we demonstrated the successful typing of SLA-DQA, SLA-DQB1, and SLA-DRB1 for 31 selected individuals comprising 26 different SLA class II haplotypes which were identified from 700 animals using the single locus typing methods. The results were identical to the known genotypes from the individual locus typing. The new method has significant benefits over the individual locus typing, including lower typing cost, use of less biomaterial, less effort and fewer errors in handling large samples for multiple loci. We also extensively characterized the haplotypes of SLA class II genes and reported three new haplotypes. Our results should serve as a basis to investigate the possible association between polymorphisms of MHC class II and differences in immune responses to exogenous antigens. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Engineering superior DNA vaccines: MHC class I single chain trimers bypass antigen processing and enhance the immune response to low affinity antigens

    PubMed Central

    Li, Lijin; Herndon, John M.; Truscott, Steven M.; Hansen, Ted H.; Fleming, Timothy P.; Goedegebuure, Peter; Gillanders, William E.

    2009-01-01

    It is commonly believed that delivery of antigen into the class I antigen presentation pathway is a limiting factor in the clinical translation of DNA vaccines. This is of particular concern in the context of cancer vaccine development as many immunodominant peptides derived from self tumor antigens are not processed and presented efficiently. To address this limitation, we have engineered completely assembled peptide/MHC class I complexes whereby all three components (class I heavy chain, β2m, and peptide) are attached by flexible linkers and expressed as a single polypeptide (single chain trimers or SCT). In this study, we tested the efficacy of progressive generations of SCT DNA vaccines engineered to (1) enhance peptide binding, (2) enhance interaction with the CD8 coreceptor, and/or (3) activate CD4+ helper T cells. Disulfide trap SCT (dtSCT) have been engineered to improve peptide binding, with mutations designed to create a disulfide bond between the class I heavy chain and the peptide linker. dtSCT DNA vaccines dramatically enhance the immune response to model low affinity antigens as measured by ELISPOT analysis and tumor challenge. SCT engineered to enhance interaction with the CD8 coreceptor have a higher affinity for the TCR/CD8 complex, and are associated with more robust CD8+ T cell responses following vaccination. Finally, SCT constructs that coexpress a universal helper epitope PADRE, dramatically enhance CD8+ T cell responses. Taken together, our data demonstrate that dtSCT DNA vaccines coexpressing a universal CD4 epitope are highly effective in generating immune responses to poorly processed and presented cancer antigens. PMID:20188246

  16. Comprehensive analysis of MHC class II genes in teleost fish genomes reveals dispensability of the peptide-loading DM system in a large part of vertebrates

    PubMed Central

    2013-01-01

    Background Classical major histocompatibility complex (MHC) class II molecules play an essential role in presenting peptide antigens to CD4+ T lymphocytes in the acquired immune system. The non-classical class II DM molecule, HLA-DM in the case of humans, possesses critical function in assisting the classical MHC class II molecules for proper peptide loading and is highly conserved in tetrapod species. Although the absence of DM-like genes in teleost fish has been speculated based on the results of homology searches, it has not been definitively clear whether the DM system is truly specific for tetrapods or not. To obtain a clear answer, we comprehensively searched class II genes in representative teleost fish genomes and analyzed those genes regarding the critical functional features required for the DM system. Results We discovered a novel ancient class II group (DE) in teleost fish and classified teleost fish class II genes into three major groups (DA, DB and DE). Based on several criteria, we investigated the classical/non-classical nature of various class II genes and showed that only one of three groups (DA) exhibits classical-type characteristics. Analyses of predicted class II molecules revealed that the critical tryptophan residue required for a classical class II molecule in the DM system could be found only in some non-classical but not in classical-type class II molecules of teleost fish. Conclusions Teleost fish, a major group of vertebrates, do not possess the DM system for the classical class II peptide-loading and this sophisticated system has specially evolved in the tetrapod lineage. PMID:24279922

  17. Elevation of c-MYC Disrupts HLA Class II-mediated Immune Recognition of Human B-cell Tumors1

    PubMed Central

    God, Jason M.; Cameron, Christine; Figueroa, Janette; Amria, Shereen; Hossain, Azim; Kempkes, Bettina; Bornkamm, Georg W.; Stuart, Robert K.; Blum, Janice S.; Haque, Azizul

    2014-01-01

    Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B-cell lymphomas. While many of c-MYC’s functions have been elucidated, its effect on the presentation of antigen (Ag) through the HLA class II pathway has not previously been reported. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report here that increased c-MYC expression has a negative effect on the ability of B-cell lymphomas to functionally present Ags/peptides to CD4+ T cells. This defect was associated with alterations in the expression of distinct co-factors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt’s lymphoma (BL) tumors and transformed cells, we show that compared to B-lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation which contribute to the immunoevasive properties of BL tumors. PMID:25595783

  18. Evaluation depth of the curve of Spee in class I, class II, and class III malocclusion: A cross sectional study

    PubMed Central

    Nayar, Sanjna; Dinakarsamy, V.; Santhosh, S.

    2015-01-01

    Occlusal plane is an essential consideration when multiple long-span posterior restorations are designed. When restorations are added to an existing tooth arrangement characterized by rotated, tipped, or extruded teeth, excursive interferences may be incorporated, resulting in detrimental squeal. The curve of Spee, which exists in the ideal natural dentition, allows harmony to exist between the anterior tooth and condylar guidance. This curve exists in the sagittal plane and is the best viewed from a lateral aspect. It permits total posterior disclusion on mandibular protrusion, given proper anterior tooth guidance. It is unclear that whether the curve of Spee is a description of the occlusal surface of each arch separately or in maximal intercuspation. The purpose of this study was to examine the differences in the depth of curve of Spee between the class I, class II, class III and to investigate the relationship of depth of curve of Spee with over jet, over-bite. PMID:26015764

  19. 78 FR 11795 - Minimum Technical Standards for Class II Gaming Systems and Equipment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ... final rule amending its technical standards for Class II gaming systems and equipment, and the rule... in the Federal Register called Minimum Technical Standards for Class II Gaming Systems and Equipment... revenue, and provide guidance to equipment manufacturers and distributors of Class II gaming systems....

  20. 7 CFR 1940.312 - Environmental assessments for Class II actions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 13 2013-01-01 2013-01-01 false Environmental assessments for Class II actions. 1940....312 Environmental assessments for Class II actions. Class II actions are basically those which exceed... more varied and substantial environmental impacts. A more detailed environmental assessment is...

  1. 40 CFR 147.3006 - Injection pressure for existing Class II wells authorized by rule.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Injection pressure for existing Class II wells authorized by rule. 147.3006 Section 147.3006 Protection of Environment ENVIRONMENTAL... Injection pressure for existing Class II wells authorized by rule. (a) Rule-authorized Class II saltwater...

  2. 40 CFR 82.23 - Transfers of allowances of class II controlled substances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Transfers of allowances of class II... § 82.23 Transfers of allowances of class II controlled substances. (a) Inter-company transfers... quantity of the transferor's class II consumption allowances, production allowances, export...

  3. 40 CFR 147.851 - State-administered program-Class II wells.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false State-administered program-Class II wells. 147.851 Section 147.851 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Kansas § 147.851 State-administered program—Class II wells. The UIC program for Class II wells in...

  4. 46 CFR 128.210 - Class II vital systems-materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.210 Class II vital systems—materials... 46 Shipping 4 2010-10-01 2010-10-01 false Class II vital systems-materials. 128.210 Section 128... chapter, materials used in Class II vital piping-systems may be accepted by the cognizant OCMI or the...

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

    PubMed Central

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

    2016-01-01

    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

  6. Evaluation of Nasal Proportions in Adults with Class I and Class II Skeletal Patterns: A Cephalometric Study.

    PubMed

    Umale, Vinay V; Singh, Kamlesh; Azam, Aftab; Bhardwaj, Madhvi; Kulshrestha, Rohit

    2017-01-01

    The aim of this study was to evaluate sexual dimorphism in nasal proportions of Class I and Class II skeletal malocclusions in adults. The sample comprised 120 patients (females 18 years and above and males 21 years and above), with no history of previous orthodontic treatment or functional jaw orthopedic treatment. They were divided into different groups based on point A-Nasion-point B (ANB) angle and gender. Groups I and II included 30 males and 30 females with skeletal class I malocclusion (ANB 0-4 degrees). Groups III and IV included 30 males and 30 females with skeletal class II malocclusion, respectively (ANB above 4 degrees). In regards to the comparison between males and females (Class I + Class II), nasal length (P < 0.001), nasal depth 1 (P < 0.001), nasal depth 2 (P < 0.001), nasobasal angle (P < 0.001), soft tissue convexity angle (P < 0.001), and nasal bone length (P < 0.008) were found to be statistically significant. Nasobasal angle was found to be significantly higher in females than in males (Class I) (P < 0.001). Nasolabial angle was prominent in class I males than in class I females (P < 0.001). Soft tissue convexity angle of Class I participants was significantly lower than that of Class II participants (P < 0.001), whereas nasobasal angle and nasomental angle of Class I participants were found to be significantly higher than that of Class II participants (P < 0.001). Sexual dimorphism was found in various nasal parameters. Significant amount of differences was found in the nasal proportions of Class I and Class II (male and female) participants.

  7. Altered transcription of genes coding for class I histocompatibility antigens in murine tumor cells

    PubMed Central

    1983-01-01

    Three murine tumors induced by Moloney murine leukemia virus (M-MLV) which exhibited loss of some or all H-2 class I antigens at the cell surface were analyzed at the DNA and RNA level with molecular probes specific of H-2 heavy chains and beta 2-microglobulin sequences. No observable difference could be detected at the DNA level between the tumors and the parent animals. However, a decrease in H-2 mRNA was observed, especially in phenotypically H-2 negative tumor, BM5R, where H-2 transcripts were at least 30-fold less abundant. These results show that an H-2-negative character may result from a general alteration in the transcription of H-2 genes, which could reflect some kind of regulatory process. PMID:6311935

  8. 25 CFR 522.5 - Disapproval of a class II ordinance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Disapproval of a class II ordinance. 522.5 Section 522.5 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.5 Disapproval of a class...

  9. 25 CFR 522.5 - Disapproval of a class II ordinance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Disapproval of a class II ordinance. 522.5 Section 522.5 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.5 Disapproval of a class...

  10. 25 CFR 522.5 - Disapproval of a class II ordinance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Disapproval of a class II ordinance. 522.5 Section 522.5 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.5 Disapproval of a class...

  11. HLA-DM is localized to conventional and unconventional MHC class II-containing endocytic compartments.

    PubMed

    Pierre, P; Denzin, L K; Hammond, C; Drake, J R; Amigorena, S; Cresswell, P; Mellman, I

    1996-03-01

    HLA-DM molecules remove invariant (Ii) chain peptides from newly synthesized MHC class II complexes. Their localization may thus delineate compartments, e.g., MIIC, specialized for loading peptides onto class II molecules. In murine A20 B cells, however, DM is not restricted to specialized endosomal class II-containing vesicles (CIIV). Although DM was found in CIIV, it was also found throughout the endocytic pathway, principally in lysosomes devoid of class II molecules. In human lymphoblasts, HLA-DM was found in structures indistinguishable from late endosomes or lysosomes, although in these cells the lysosomes contained MHC class II molecules. Thus, the distribution of HLA-DM does not necessarily identify specialized class II compartments. Many "MIIC" may represent conventional lysosomes that accumulate MHC class II and HLA-DM in a number of cell types.

  12. HLA class II defects in Burkitt lymphoma: bryostatin-1-induced 17 kDa protein restores CD4+ T-cell recognition.

    PubMed

    Hossain, Azim; God, Jason M; Radwan, Faisal F Y; Amria, Shereen; Zhao, Dan; Bethard, Jennifer R; Haque, Azizul

    2011-01-01

    While the defects in HLA class I-mediated Ag presentation by Burkitt lymphoma (BL) have been well documented, CD4+ T-cells are also poorly stimulated by HLA class II Ag presentation, and the reasons underlying this defect(s) have not yet been fully resolved. Here, we show that BL cells are deficient in their ability to optimally stimulate CD4+ T cells via the HLA class II pathway. The observed defect was not associated with low levels of BL-expressed costimulatory molecules, as addition of external co-stimulation failed to result in BL-mediated CD4+ T-cell activation. We further demonstrate that BL cells express the components of the class II pathway, and the defect was not caused by faulty Ag/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Treatment of BL with broystatin-1, a potent modulator of protein kinase C, led to significant improvement of functional class II Ag presentation in BL. The restoration of immune recognition appeared to be linked with an increased expression of a 17 kDa peptidylprolyl-like protein. These results demonstrate the presence of a specific defect in HLA class II-mediated Ag presentation in BL and reveal that treatment with bryostatin-1 could lead to enhanced immunogenicity.

  13. HLA Class II Defects in Burkitt Lymphoma: Bryostatin-1-Induced 17 kDa Protein Restores CD4+ T-Cell Recognition

    PubMed Central

    Hossain, Azim; God, Jason M.; Radwan, Faisal F. Y.; Amria, Shereen; Zhao, Dan; Bethard, Jennifer R.; Haque, Azizul

    2011-01-01

    While the defects in HLA class I-mediated Ag presentation by Burkitt lymphoma (BL) have been well documented, CD4+ T-cells are also poorly stimulated by HLA class II Ag presentation, and the reasons underlying this defect(s) have not yet been fully resolved. Here, we show that BL cells are deficient in their ability to optimally stimulate CD4+ T cells via the HLA class II pathway. The observed defect was not associated with low levels of BL-expressed costimulatory molecules, as addition of external co-stimulation failed to result in BL-mediated CD4+ T-cell activation. We further demonstrate that BL cells express the components of the class II pathway, and the defect was not caused by faulty Ag/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Treatment of BL with broystatin-1, a potent modulator of protein kinase C, led to significant improvement of functional class II Ag presentation in BL. The restoration of immune recognition appeared to be linked with an increased expression of a 17 kDa peptidylprolyl-like protein. These results demonstrate the presence of a specific defect in HLA class II-mediated Ag presentation in BL and reveal that treatment with bryostatin-1 could lead to enhanced immunogenicity. PMID:22162713

  14. Interpretation of biphasic dissociation kinetics for isomeric class II major histocompatibility complex-peptide complexes

    PubMed Central

    Anderson, TG; McConnell, HM

    1999-01-01

    Antigenic peptides bound to class II major histocompatibility complex (MHC) proteins play a key role in the distinction between "self" and "nonself" by the cellular immune system. Although the formation and dissociation of these complexes are often thought of in terms of the simple mechanism MHC + P &rlharr; MHC-P, studies of MHC-peptide dissociation kinetics suggest that multiple interconverting forms of the bound MHC-peptide complex can be formed. However, the precise relationship between observed dissociation data and proposed multiple-complex mechanisms has not been systematically examined. Here we provide a mathematical analysis to fill this gap and attempt to clarify the kinetic behavior that is expected to result from the proposed mechanisms. We also examine multiple-complex dynamics that can be "hidden" in conventional experiments. Although we focus on MHC-peptide interactions, the analysis provided here is fully general and applies to any ligand-receptor system having two distinct bound states. PMID:10545347

  15. Denatured class I human leukocyte antigen antibodies in sensitized kidney recipients: prevalence, relevance, and impact on organ allocation.

    PubMed

    Visentin, Jonathan; Guidicelli, Gwendaline; Bachelet, Thomas; Jacquelinet, Christian; Audry, Benoît; Nong, Thoa; Dubois, Valérie; Moreau, Jean-François; Lee, Jar-How; Couzi, Lionel; Merville, Pierre; Taupin, Jean-Luc

    2014-10-15

    Single antigen flow beads assays may overestimate sensitization because of the detection of supposedly irrelevant antibodies recognizing denatured class I human leukocyte antigens (HLAs). Sera of 323 HLA-sensitized kidney transplant candidates positive with a class I HLA single antigen flow beads assay were retested after acid treatment of the beads. Denatured HLA antibodies were identified according to ratio between the measured fluorescence intensity for treated and nontreated beads. T-lymphocyte flow cytometry crossmatches were performed to characterize the ability of these antibodies to recognize HLA on normal cells as a surrogate of their potential clinical relevance. Their impact on organ allocation was evaluated through a calculated panel reactive antibody. The utility of single antigen flow beads largely devoid of denatured HLA (iBeads) was also evaluated. Denatured HLA antibodies were detected in 39% of the patients. They provided much less positive flow cytometry crossmatches than anti-native HLA antibodies (16% vs. 83%, P<0.0001). Removing the HLA-A and HLA-B antigens targeted by denatured HLA antibodies from unacceptable antigens lowered the calculated panel reactive antibody for 90 patients, sometimes dramatically. The iBeads assay demonstrated nearly the same ability to predict crossmatch results than the acid treatment assay. Denatured class I HLA antibodies are common, but the antigens they target should not be considered as unacceptable in most cases, because they negatively impact access to a transplant while predominantly providing negative sensitive crossmatches. The iBeads assay seems to be a valuable alternative to better define unacceptable antigens.

  16. Alteration of a Single Hydrogen Bond between Class II Molecules and Peptide Results in Rapid Degradation of Class II Molecules after Invariant Chain Removal

    PubMed Central

    Ceman, Stephanie; Wu, Shenhong; Jardetzky, Theodore S.; Sant, Andrea J.

    1998-01-01

    To characterize the importance of a highly conserved region of the class II β chain, we introduced an amino acid substitution that is predicted to eliminate a hydrogen bond formed between the class II molecule and peptide. We expressed the mutated β chain with a wild-type α chain in a murine L cell by gene transfection. The mutant class II molecule (81βH−) assembles normally in the endoplasmic reticulum and transits the Golgi complex. When invariant chain (Ii) is coexpressed with 81βH−, the class II–Ii complex is degraded in the endosomes. Expression of 81βH− in the absence of Ii results in a cell surface expressed molecule that is susceptible to proteolysis, a condition reversed by incubation with a peptide known to associate with 81βH−. We propose that 81βH− is protease sensitive because it is unable to productively associate with most peptides, including classII–associated invariant chain peptides. This model is supported by our data demonstrating protease sensitivity of peptide-free wild-type I-Ad molecules. Collectively, our results suggest both that the hydrogen bonds formed between the class II molecule and peptide are important for the integrity and stability of the complex, and that empty class II molecules are protease sensitive and degraded in endosomes. One function of DM may be to insure continuous groove occupancy of the class II molecule. PMID:9841927

  17. Prevalence of Alloimmunization to Human Platelet Antigen Glycoproteins and Human Leucocyte Antigen Class I in β Thalassemia Major Patients in Western India.

    PubMed

    Philip, Joseph; Kumar, Sudeep; Chatterjee, T; Mallhi, R S

    2014-12-01

    Present management of β thalassemia major by regular packed red blood cell (PRBC) transfusions poses risk of alloimmunization not only to red blood cell antigens, but also to human platelet antigens (HPA) and Human leucocyte antigens class I (HLA I). However data in this context is very limited in Indian population. The aim of the study was to determine the prevalence of alloimmunization to HPA and HLA I in β thalassemia major patients who have received multiple PRBC transfusions over the years. A cross sectional study was performed at our tertiary care blood bank. β thalassemia major patients of more than 6 years of age were included who were receiving fresh, leucoreduced and irradiated PRBC units regularly with annual requirement of more than ten PRBC transfusions. A total of 9 out of 80 (11.25 %) patients were found to be alloimmunized for HPA antigens of various specificity and 24 out of 80 (30 %) developed antibodies to HLA I. The awareness of development of alloimmunization to HPA and HLA antigens in multi PRBC transfused thalassemics, despite use of leucofilters will prompt us, to look for improvement in our current PRBC preparations to minimise platelet alloimmunisation. Further studies are required to validate the findings and build the base line data in this regard. This is of importance, especially in view of providing suitable cross-matched platelets when required in future especially when considering future haematopoietic stem cell transplantation (HSCT).

  18. Characterization and expression of MHC class II alpha and II beta genes in mangrove red snapper (Lutjanus argentimaculatus).

    PubMed

    Wang, Tianyan; Tan, Shangjin; Cai, Zhonghua

    2015-12-01

    The major histocompatibility complex (MHC) class II plays a key role in adaptive immunity by presenting foreign peptides to CD4(+) T cells and by triggering the adaptive immune response. While the structure and function of MHC class II have been well characterized in mammalian, limited research has been done on fishes. In this study, we characterized the gene structure and expression of MHC class II α (Lunar-DAA) and II β (Lunar-DAB) of mangrove red snapper (Lutjanus argentimaculatus). Both genes shared, respectively, a high similarity and typical features with other vertebrate MHC class II α and II β. The phylogenetic analysis of the deduced peptides revealed that both Lunar-DAA and Lunar-DAB were located in the teleost subclass. Western blotting analyses indicated that both MHC class II α and II β were expressed ubiquitously in immune-related cells, tissues and organs, and that MHC class II α and II β chains existed mainly as heterodimers. While it was highly expressed in gills, thymus, head kidney (HK), spleen, head kidney macrophage and spleen leucocytes, MHC class II β chain was expressed with a low abundance in skin, intestine, stomach and heart. The highest expression of MHC class II β in thymus confirmed the conclusion that thymus is one of the primary lymphoid organs in fishes. The detection of MHC class II αβ dimers in HK macrophages and spleen leucocytes indicated that HK macrophages and spleen leucocytes play a critical role in the adaptive immunity in fishes. All these results provide valuable information for understanding the structure of MHC class II α and II β and their function in immune responses.

  19. Multiple HLA class I and II associations in classical Hodgkin lymphoma and EBV status defined subgroups.

    PubMed

    Huang, Xin; Kushekhar, Kushi; Nolte, Ilja; Kooistra, Wierd; Visser, Lydia; Bouwman, Ilby; Kouprie, Niels; Veenstra, Rianne; van Imhoff, Gustaaf; Olver, Bianca; Houlston, Richard S; Poppema, Sibrand; Diepstra, Arjan; Hepkema, Bouke; van den Berg, Anke

    2011-11-10

    The pathogenesis of classical Hodgkin lymphoma (cHL) involves environmental and genetic factors. To explore the role of the human leukocyte antigen (HLA) genes, we performed a case-control genotyping study in 338 Dutch cHL patients and more than 5000 controls using a PCR-based sequence-specific oligonucleotide probe hybridization approach. HLA-A68 and HLA-DR11 (5) were significantly increased in the cHL patient population compared with the controls. Three class II associations were observed in the EBV(-) cHL population with an increase of HLA-DR15 (2) and a decrease of HLA-DR4 and HLA-DR7. Allele frequencies of HLA-A1, HLA-B37, and HLA-DR10 were significantly increased in the EBV(+) cHL population; these alleles are in strong linkage disequilibrium and form a common haplotype in whites. The allele frequency of HLA-A2 was significantly decreased in the EBV(+) cHL population. Sequence-specific oligonucleotide probe analysis revealed significant differences between EBV(+) and EBV(-) cHL patients for 19 probes that discriminate between HLA-A*01 and HLA-A*02. In conclusion, the HLA-A1 and HLA-A2 antigens and not specific single nucleotide variants shared by multiple alleles are responsible for the association with EBV(+) cHL. Furthermore, several new protective and predisposing HLA class I and II associations for the EBV(+), the EBV(-), and the entire cHL population were identified.

  20. In silico designing breast cancer peptide vaccine for binding to MHC class I and II: A molecular docking study.

    PubMed

    Mahdavi, Manijeh; Moreau, Violaine

    2016-12-01

    Antigenic peptides or cancer peptide vaccines can be directly delivered to cancer patients to produce immunologic responses against cancer cells. Specifically, designed peptides can associate with Major Histocompatibility Complex (MHC) class I or II molecules on the cell surface of antigen presenting cells activating anti-tumor effector mechanisms by triggering helper T cell (Th) or cytotoxic T cells (CTL). In general, high binding to MHCs approximately correlates with in vivo immunogenicity. Consequently, a molecular docking technique was run on a library of novel discontinuous peptides predicted by PEPOP from Human epidermal growth factor receptor 2 (HER2 ECD) subdomain III. This technique is expected to improve the prediction accuracy in order to identify the best MHC class I and II binder peptides. Molecular docking analysis through GOLD identified the peptide 1412 as the best MHC binder peptide to both MHC class I and II molecules used in the study. The GOLD results predicted HLA-DR4, HLA-DP2 and TCR as the most often targeted receptors by the peptide 1412. These findings, based on bioinformatics analyses, can be exploited in further experimental analyses in vaccine design and cancer therapy to find possible proper approaches providing beneficial effects.

  1. Major histocompatibility complex class II alleles and haplotypes associated with non-suppurative meningoencephalitis in greyhounds.

    PubMed

    Shiel, R E; Kennedy, L J; Nolan, C M; Mooney, C T; Callanan, J J

    2014-09-01

    Non-suppurative meningoencephalitis is a breed-restricted canine neuroinflammatory disorder affecting young greyhounds in Ireland. A genetic risk factor is suspected because of the development of disease in multiple siblings and an inability to identify a causative infectious agent. The aim of this study was to examine potential associations between dog leucocyte antigen (DLA) class II haplotype and the presence of the disease. DLA three locus haplotypes were determined in 31 dogs with non-suppurative meningoencephalitis and in 115 healthy control dogs using sequence-based typing (SBT) methods. All dogs were unrelated at the parental level. Two haplotypes (DRB1*01802/DQA1*00101/DQB1*00802 and DRB1*01501/DQA1*00601/DQB1*02201) were significantly (P = 0.0099 and 0.037) associated with the presence of meningoencephalitis, with odds ratios (95% confidence interval) of 5.531 (1.168-26.19) and 3.736 (1.446-9.652), respectively. These results confirm that there is an association between DLA class II haplotype and greyhound meningoencephalitis, suggesting an immunogenetic risk factor for the development of the disease. Greyhound meningoencephalitis may be a suitable model for human neuroinflammatory diseases with an immunogenetic component. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Prostate Cancer Immunotherapy: Exploiting the HLA Class II Pathway in Vaccine Design.

    PubMed

    Doonan, Bently P; Haque, Azizul

    2015-08-01

    Prostate cancer is the second most diagnosed cancer in men and current treatment of advanced prostate cancer is ineffective. Immunotherapy has emerged as a promising treatment option for metastatic prostate cancer but its clinical application is still in the early stages of development. In order to treat metastatic prostate tumors, new directions must be taken to improve current immunotherapeutic strategies. These include the identification of effective tumor antigens (Ags), the induction of the HLA class II pathway for Ag processing and CD4(+) T cell activation, and the ability of tumor cells to act like Ag presenting cells. In this review, we suggest a model for tumor Ag selection, epitope modification and self-processing for presentation by class II proteins as a means of restoring immune activation and tumor clearance. We also outline the importance of a Gamma-IFN-inducible Lysosomal Thiol reductase (GILT) in Ag and modified peptide processing by tumor cells, generation of functional epitopes for T cell recognition, and inclusion of immune checkpoint blockers in cancer immunotherapy. Taken together, this review provides a framework for the future development of novel cancer vaccines and the improvement of existing immunotherapeutics in prostate cancer.

  3. Btn2a2, a T cell immunomodulatory molecule coregulated with MHC class II genes

    PubMed Central

    Sarter, Kerstin; Leimgruber, Elisa; Gobet, Florian; Agrawal, Vishal; Dunand-Sauthier, Isabelle; Barras, Emmanuèle; Mastelic-Gavillet, Béatris; Kamath, Arun; Fontannaz, Paola; Guéry, Leslie; Duraes, Fernanda do Valle; Lippens, Carla; Ravn, Ulla; Santiago-Raber, Marie-Laure; Magistrelli, Giovanni; Fischer, Nicolas; Siegrist, Claire-Anne; Hugues, Stéphanie

    2016-01-01

    Evidence has recently emerged that butyrophilins, which are members of the extended B7 family of co-stimulatory molecules, have diverse functions in the immune system. We found that the human and mouse genes encoding butyrophilin-2A2 (BTN2A2) are regulated by the class II trans-activator and regulatory factor X, two transcription factors dedicated to major histocompatibility complex class II expression, suggesting a role in T cell immunity. To address this, we generated Btn2a2-deficient mice. Btn2a2−/− mice exhibited enhanced effector CD4+ and CD8+ T cell responses, impaired CD4+ regulatory T cell induction, potentiated antitumor responses, and exacerbated experimental autoimmune encephalomyelitis. Altered immune responses were attributed to Btn2a2 deficiency in antigen-presenting cells rather than T cells or nonhematopoietic cells. These results provide the first genetic evidence that BTN2A2 is a co-inhibitory molecule that modulates T cell–mediated immunity. PMID:26809444

  4. HLA class II sequence variants influence tuberculosis risk in populations of European ancestry

    PubMed Central

    Sveinbjornsson, Gardar; Gudbjartsson, Daniel F.; Halldorsson, Bjarni V.; Kristinsson, Karl G.; Gottfredsson, Magnus; Barrett, Jeffrey C.; Gudmundsson, Larus J.; Blondal, Kai; Gylfason, Arnaldur; Gudjonsson, Sigurjon Axel; Helgadottir, Hafdis T.; Jonasdottir, Adalbjorg; Jonasdottir, Aslaug; Karason, Ari; Kardum, Ljiljana Bulat; Knežević, Jelena; Kristjansson, Helgi; Kristjansson, Mar; Love, Arthur; Luo, Yang; Magnusson, Olafur T.; Sulem, Patrick; Kong, Augustine; Masson, Gisli; Thorsteinsdottir, Unnur; Dembic, Zlatko; Nejentsev, Sergey; Blondal, Thorsteinn; Jonsdottir, Ingileif; Stefansson, Kari

    2016-01-01

    Mycobacterium tuberculosis (M. tuberculosis) infections cause 9.0 million new tuberculosis (TB) cases and 1.5 million deaths annually1. To search for sequence variants that confer risk of TB we tested 28.3 million variants identified through whole-genome sequencing of 2,636 Icelanders for association with TB (8,162 cases and 277,643 controls), pulmonary TB (PTB), and M. tuberculosis infection. We found association of three sequence variants in the HLA class II region: rs557011[T] (MAF=40.2%) with M. tuberculosis infection (OR =1.14, P=3.1×10-13) and PTB (OR=1.25, P=5.8×10-12) and rs9271378[G] (MAF=32.5%) with PTB (OR=0.78, P=2.5×10-12), both located between HLA-DQA1 and HLA-DRB1. Finally, a missense variant p.Ala210Thr in HLA-DQA1, (MAF=19.1%, rs9272785) shows association with M. tuberculosis infection (P=9.3×10-9, OR=1.14). The association of these variants with PTB was replicated in large samples of European ancestry from Russia and Croatia (P< 5.9×10-4). These findings demonstrate that the HLA class II region contributes to the complex genetic risk of tuberculosis, possibly through reduced presentation of protective M. tuberculosis antigens to T cells. PMID:26829749

  5. Prostate Cancer Immunotherapy: Exploiting the HLA Class II Pathway in Vaccine Design

    PubMed Central

    Doonan, Bently P; Haque, Azizul

    2015-01-01

    Prostate cancer is the second most diagnosed cancer in men and current treatment of advanced prostate cancer is ineffective. Immunotherapy has emerged as a promising treatment option for metastatic prostate cancer but its clinical application is still in the early stages of development. In order to treat metastatic prostate tumors, new directions must be taken to improve current immunotherapeutic strategies. These include the identification of effective tumor antigens (Ags), the induction of the HLA class II pathway for Ag processing and CD4+ T cell activation, and the ability of tumor cells to act like Ag presenting cells. In this review, we suggest a model for tumor Ag selection, epitope modification and self-processing for presentation by class II proteins as a means of restoring immune activation and tumor clearance. We also outline the importance of a Gamma-IFN-inducible Lysosomal Thiol reductase (GILT) in Ag and modified peptide processing by tumor cells, generation of functional epitopes for T cell recognition, and inclusion of immune checkpoint blockers in cancer immunotherapy. Taken together, this review provides a framework for the future development of novel cancer vaccines and the improvement of existing immunotherapeutics in prostate cancer. PMID:26807308

  6. The first step of peptide selection in antigen presentation by MHC class I molecules

    PubMed Central

    Garstka, Malgorzata A.; Fish, Alexander; Celie, Patrick H. N.; Joosten, Robbie P.; Janssen, George M. C.; Berlin, Ilana; Hoppes, Rieuwert; Stadnik, Magda; Janssen, Lennert; Ovaa, Huib; van Veelen, Peter A.; Perrakis, Anastassis; Neefjes, Jacques

    2015-01-01

    MHC class I molecules present a variable but limited repertoire of antigenic peptides for T-cell recognition. Understanding how peptide selection is achieved requires mechanistic insights into the interactions between the MHC I and candidate peptides. We find that, at first encounter, MHC I H-2Kb considers a wide range of peptides, including those with expanded N termini and unfitting anchor residues. Discrimination occurs in the second step, when noncanonical peptides dissociate with faster exchange rates. This second step exhibits remarkable temperature sensitivity, as illustrated by numerous noncanonical peptides presented by H-2Kb in cells cultured at 26 °C relative to 37 °C. Crystallographic analyses of H-2Kb–peptide complexes suggest that a conformational adaptation of H-2Kb drives the decisive step in peptide selection. We propose that MHC class I molecules consider initially a large peptide pool, subsequently refined by a temperature-sensitive induced-fit mechanism to retain the canonical peptide repertoire. PMID:25605945

  7. The first step of peptide selection in antigen presentation by MHC class I molecules.

    PubMed

    Garstka, Malgorzata A; Fish, Alexander; Celie, Patrick H N; Joosten, Robbie P; Janssen, George M C; Berlin, Ilana; Hoppes, Rieuwert; Stadnik, Magda; Janssen, Lennert; Ovaa, Huib; van Veelen, Peter A; Perrakis, Anastassis; Neefjes, Jacques

    2015-02-03

    MHC class I molecules present a variable but limited repertoire of antigenic peptides for T-cell recognition. Understanding how peptide selection is achieved requires mechanistic insights into the interactions between the MHC I and candidate peptides. We find that, at first encounter, MHC I H-2K(b) considers a wide range of peptides, including those with expanded N termini and unfitting anchor residues. Discrimination occurs in the second step, when noncanonical peptides dissociate with faster exchange rates. This second step exhibits remarkable temperature sensitivity, as illustrated by numerous noncanonical peptides presented by H-2K(b) in cells cultured at 26 °C relative to 37 °C. Crystallographic analyses of H-2K(b)-peptide complexes suggest that a conformational adaptation of H-2K(b) drives the decisive step in peptide selection. We propose that MHC class I molecules consider initially a large peptide pool, subsequently refined by a temperature-sensitive induced-fit mechanism to retain the canonical peptide repertoire.

  8. Characterization and evolution of MHC class II B genes in Galápagos marine iguanas (Amblyrhynchus cristatus).

    PubMed

    Glaberman, Scott; Moreno, Maria A; Caccone, Adalgisa

    2009-08-01

    Major histocompatibility complex (MHC) class II molecules play a key role in the adaptive immune system of vertebrates. Class II B genes appear to evolve in a very different manner in mammals and birds. Orthology is commonly observed among mammal loci, while genes tend to cluster phylogenetically within bird species. Here we present class II B data from a representative of another major group of amniotes, the squamates (i.e. lizards, snakes, amphisbaenians), with the ultimate goal of placing mammalian and avian MHC evolution into a broader context. In this study, eight class II B cDNA sequences were obtained from the Galápagos marine iguana (Amblyrhynchus cristatus) which were divided into five locus groups, Amcr-DAB1 through -DAB5, based on similarities along most of the coding and noncoding portions of the transcribed gene. All marine iguana sequences were monophyletic with respect to class II genes from other vertebrates indicating that they originated from a common ancestral locus after squamates split from other reptiles. The beta-1 domain, which is involved in antigen binding, exhibited signatures of positive selection as well as interlocus gene conversion in both long and short tracts-a pattern also observed in birds and fish, but not in mammals. On the other hand, the beta-2 domain was divergent between gene groups, which is characteristic of mammals. Based on these results, we preliminarily show that squamate class II B genes have been shaped by a unique blend of evolutionary forces that have been observed in differing degrees in other vertebrates.

  9. Genetic complexity of regulatory mutants defective for HLA class II gene expression

    SciTech Connect

    Seidl, C.; Saraiya, C.; Osterweil, Z.; Fu, Y. Ping; Lee, J.S. )

    1992-03-01

    MHC (called HLA in man) class II genes play an essential role in cell-mediated immunity. Absence of HLA class II Ag on B lymphocytes is the basis of some congenital immunodeficiencies (CID). The authors have studied CID by generating transient heterokaryons from cell lines of such patients, and report that the mutations fall into four complementation groups. In addition, fusions with the HLA class II deletion mutant 721.180 indicate that the genetic defects for each group in HLA class II expression map outside the HLA class II region. A small HLA-DRA promoter fragment is sufficient to drive expression of a reporter gene in normal B cell lines, but expression from the same construct is clearly reduced in mutant cell lines representative of all four complementation groups. This confirms earlier results that indicate defective transcription of HLA class II genes in the class II[sup [minus

  10. Characterization of class I- and class II-like major histocompatibility complex loci in pedigrees of North Atlantic right whales.

    PubMed

    Gillett, Roxanne M; Murray, Brent W; White, Bradley N

    2014-01-01

    North Atlantic right whales have one of the lowest levels of genetic variation at minisatellite loci, microsatellite loci, and mitochondrial control region haplotypes among mammals. Here, adaptive variation at the peptide binding region of class I and class II DRB-like genes of the major histocompatibility complex was assessed. Amplification of a duplicated region in 222 individuals revealed at least 11 class II alleles. Six alleles were assigned to the locus Eugl-DRB1 and 5 alleles were assigned to the locus Eugl-DRB2 by assessing segregation patterns of alleles from 81 parent/offspring pedigrees. Pedigree analysis indicated that these alleles segregated into 12 distinct haplotypes. Genotyping a smaller subset of unrelated individuals (n = 5 and 10, respectively) using different primer sets revealed at least 2 class II pseudogenes (with ≥ 4 alleles) and at least 3 class I loci (with ≥ 6 alleles). Class II sequences were significantly different from neutrality at peptide binding sites suggesting loci may be under the influence of balancing selection. Trans-species sharing of alleles was apparent for class I and class II sequences. Characterization of class II loci represents the first step in determining the relationship between major histocompatibility complex variability and factors affecting health and reproduction in this species.

  11. MHC class I antigens and tumour-infiltrating leucocytes in laryngeal cancer: long-term follow-up.

    PubMed Central

    Esteban, F.; Redondo, M.; Delgado, M.; Garrido, F.; Ruiz-Cabello, F.

    1996-01-01

    Alteration in MHC class I expression may be used by cancer cells to avoid immune destruction. Much experimental evidence supports this idea, although survival studies are very scarce. To investigate whether the presence or absence of HLA-A, -B and -C antigens in laryngeal carcinoma influences survival, a series of 60 primary laryngeal tumours treated surgically and normal tissues were evaluated in frozen sections for the expression of MHC class I antigens and tumour-infiltrating leucocytes (CD3, CD4, CD8, CD11b, CD1, CD20 and CD16), using monoclonal antibodies and the APAAP, technique. Long-term follow-up from the patients is available, ranging from 6 to 10 years. Thirteen tumours presented total HLA-ABC loss, five selective losses of HLA-A antigens and one absence of HLA-B antigens. Total losses were statistically associated with several clinical and pathological parameters, but there were no differences regarding tumour-infiltrating leucocytes. After conducting a prospective study, only T and N staging and scoring according to Glanz's malignancy classification were found to be independently related to patients' outcome. From our data, we conclude that neither complete loss of HLA class I antigens nor tumour-infiltrating leucocytes appear to influence survival in squamous cell carcinoma of the larynx. PMID:8956796

  12. Detection of donor-specific anti-HLA class I and II antibodies using antibody monitoring system.

    PubMed

    Yang, C W; Oh, E J; Lee, S B; Moon, I S; Kim, D G; Choi, B S; Park, S C; Choi, Y J; Park, Y J; Han, K

    2006-11-01

    The antibody monitoring system (AMS, GTI Inc) is a solid enzyme-linked immunosorbent assay (ELISA) crossmatch test for the detection of immunoglobulin G (IgG) antibody to donor-specific solubilized HLA class I and class II antigens. The objective of this study was to compare the results of the AMS assay with donor-specific anti-HLA IgG antibodies (DS-HLA Abs), as determined by ELISA panel reactive antibody (PRA) and the flow cytometric crossmatch test (FCXM). A total of 107 sera were screened for the presence of HLA Abs by ELISA PRA (LAT-M, One-Lambda Inc), the DS-HLA Abs were determined in 34 serum samples (31.8%) by an ELISA panel (LAT class I and class II, One-Lambda Inc) and FCXM. The FCXM and AMS assays were performed with matched lymphocytes from 56 donors. There was a significant degree of concordance (89.7%) between the two tests (P < .001). The sensitivity, specificity, positive predictive value, and negative predictive value of AMS assay to detect DS-HLA Abs was 88.2%, 94.5%, 88.2%, and 94.5%, respectively. The AMS is a simple, objective test, which has several advantages over the cell-based crossmatch test, such as elimination of non-HLA antibody reactivity, elimination of non-donor-specific antibody reactivity, no need for viable cells, and preparation of the donor's HLA antigens in advance. In summary, this study suggested that AMS may be useful as a supportive crossmatch test or as a monitoring test after transplantation to detect class I or class II DS-HLA Abs.

  13. Polycomb recruitment at the Class II transactivator gene.

    PubMed

    Boyd, Nathaniel H; Morgan, Julie E; Greer, Susanna F

    2015-10-01

    The Class II Transactivator (CIITA) is the master regulator of Major Histocompatibility Class II (MHC II) genes. Transcription of CIITA through the IFN-γ inducible CIITA promoter IV (CIITA pIV) during activation is characterized by a decrease in trimethylation of histone H3 lysine 27 (H3K27me3), catalyzed by the histone methyltransferase Enhancer of Zeste Homolog 2 (EZH2). While EZH2 is the known catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) and is present at the inactive CIITA pIV, the mechanism of PRC2 recruitment to mammalian promoters remains unknown. Here we identify two DNA-binding proteins, which interact with and regulate PRC2 recruitment to CIITA pIV. We demonstrate Yin Yang 1 (YY1) and Jumonji domain containing protein 2 (JARID2) are binding partners along with EZH2 in mammalian cells. Upon IFN-γ stimulation, YY1 dissociates from CIITA pIV while JARID2 binding to CIITA pIV increases, suggesting novel roles for these proteins in regulating expression of CIITA pIV. Knockdown of YY1 and JARID2 yields decreased binding of EZH2 and H3K27me3 at CIITA pIV, suggesting important roles for YY1 and JARID2 at CIITA pIV. JARID2 knockdown also results in significantly elevated levels of CIITA mRNA upon IFN-γ stimulation. This study is the first to identify novel roles of YY1 and JARID2 in the epigenetic regulation of the CIITA pIV by recruitment of PRC2. Our observations indicate the importance of JARID2 in CIITA pIV silencing, and also provide a novel YY1-JARID2-PRC2 regulatory complex as a possible explanation of differential PRC2 recruitment at inducible versus permanently silenced genes.

  14. Relationships among nasal resistance, adenoids, tonsils, and tongue posture and maxillofacial form in Class II and Class III children.

    PubMed

    Iwasaki, Tomonori; Sato, Hideo; Suga, Hokuto; Takemoto, Yoshihiko; Inada, Emi; Saitoh, Issei; Kakuno, Eriko; Kanomi, Ryuzo; Yamasaki, Youichi

    2017-05-01

    The purpose of this study was to clarify the relationships between upper airway factors (nasal resistance, adenoids, tonsils, and tongue posture) and maxillofacial forms in Class II and III children. Sixty-four subjects (mean age, 9.3 years) with malocclusion were divided into Class II and Class III groups by ANB angles. Nasal resistance was calculated using computational fluid dynamics from cone-beam computed tomography data. Adenoids, tonsils, and tongue posture were evaluated in the cone-beam computed tomography images. The groups were compared using Mann-Whitney U tests and Student t tests. The Spearman rank correlations test assessed the relationships between the upper airway factors and maxillofacial form. Nasal resistance of the Class II group was significantly larger than that of the