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Class II Antigens (class + ii_antigen)
Selected AbstractsPost-transplant reactivation of hepatitis C virus: lymphocyte infiltration and the expression of adhesion molecules and their ligands in liver allografts,APMIS, Issue 4 2006KATRI LIPSON Hepatitis C virus (HCV) recurrence after liver transplantation has been associated with chronic rejection. Biopsies from 10 patients with post-transplant HCV were examined for expression of adhesion molecules ICAM-1, VCAM-1, and ELAM-1, number of lymphocytes positive for their ligands LFA-1, VLA-4, and SLeX, and activation markers MHC class II antigens and IL2-R by immunohistochemistry. The phenotypes of the graft-infiltrating lymphocytes were determined. Results were compared to those for patients with normal graft function or rejection. Five recipients with HCV reactivation and one with de novo HCV had a biopsy available showing induction of ICAM-1 in sinusoidal endothelium (p<0.05) and hepatocytes (p<0.01), and Class II antigens in hepatocytes (p<0.01), compared to normal controls. Lymphocytes in the graft infiltrate expressed LFA-1, VLA-4, and Class II antigens, but IL2-R was not significantly expressed. CD3+, CD4+, and CD8+ cells were observed. In our study, HCV recurrence was not associated with acute or chronic rejection, and the inflammation was due to the viral infection. [source] Effect of triclosan on interferon-, production and major histocompatibility complex class II expression in human gingival fibroblastsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2000Manal Mustafa Abstract Background, aims: The effect of triclosan (2,4,4,-trichloro-2,-hydroxyl-diphenyl ether) on the production of interferon-, (IFN-,) and the expression of major histocompatibility complex (MHC) class II antigen was studied in human gingival fibroblasts isolated from 4 individuals. Methods/Results: AII cell lines demonstrated high IFN-, production in 24-h cultures of human gingival fibroblasts stimulated by phytohemagglutinin (PHA) (5 ,g/ml). Human gingival fibroblasts showed a high expression of MHC class II when stimulated with 500 and 1000 pg/ml rIFN-, in 7-day cultures. Treatment of the cells with triclosan (0.5 ,g/ml) reduced both IFN-, production and MHC class II expression in human gingival fibroblast cultures. Similar inhibitory effects on IFN-, production and MHC class II expression were observed when the anti-inflammatory agent dexamethazone (1 ,M) was used. Conclusion: The present study further supports the view that the agent has an anti-inflammatory effect in addition to its antibacterial capacity. [source] Induction of cytotoxic T lymphocytes by dendritic cells pulsed with murine leukemic cell RNAAMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2004Chul Won Jung Abstract Peptide-pulsed dendritic cells can stimulate T cells showing specific cytotoxicity in chronic myelogenous leukemia. We tried to induce a specific cytotoxic T-cell response stimulated by RNA-pulsed dendritic cells in acute myelogenous leukemia. The total RNA of WEHI-3BD+, a myelomonocytic leukemia cell line derived from BALB/c mice, was transfected into dendritic cells induced from bone marrow nucleated cells of BALB/c mice with granulocyte macrophage colony-stimulating factor (GM-CSF) and lipopolysaccharide (LPS) using liposome. RNA-pulsed dendritic cells were injected into the peritoneal cavity of BALB/c mice, and splenic T cells were isolated for antigen-stimulated proliferation and leukemia-specific cytotoxicity assay. Cultured bone marrow nucleated cells expressed dendritic cell markers including MHC class II antigen, CD80, CD86, and CD11c. T cells stimulated by RNA-pulsed dendritic cells showed enhanced proliferation than those stimulated by unpulsed dendritic cells (P = 0.05) and showed dose-dependent specific cytotoxicity against WEHI-3BD+ cells. We concluded total RNA-pulsed dendritic cells could induce a specific T-cell cytotoxicity in acute myelogenous leukemia. Am. J. Hematol. 75:121,127, 2004. © 2004 Wiley-Liss, Inc. [source] Major histocompatibility complex class II, fetal skin dendritic cells are potent accessory cells of polyclonal T-cell responsesIMMUNOLOGY, Issue 2 2000A. Elbe-Bürger Summary Whereas dendritic cells (DC) and Langerhans cells (LC) isolated from organs of adult individuals express surface major histocompatibility complex (MHC) class II antigens, DC lines generated from fetal murine skin, while capable of activating naive, allogeneic CD8+ T cells in a MHC class I-restricted fashion, do not exhibit anti-MHC class II surface reactivity and fail to stimulate the proliferation of naive, allogeneic CD4+ T cells. To test whether the CD45+ MHC class I+ CD80+ DC line 80/1 expresses incompetent, or fails to transcribe, MHC class II molecules, we performed biochemical and molecular studies using Western blot and polymerase chain reaction analysis. We found that 80/1 DC express MHC class II molecules neither at the protein nor at the transcriptional level. Ultrastructural examination of these cells revealed the presence of a LC-like morphology with indented nuclei, active cytoplasm, intermediate filaments and dendritic processes. In contrast to adult LC, no LC-specific cytoplasmic organelles (Birbeck granules) were present. Functionally, 80/1 DC in the presence, but not in the absence, of concanavalin A and anti-T-cell receptor monoclonal antibodies stimulated a vigorous proliferative response of naive CD4+ and CD8+ T cells. Furthermore, we found that the anti-CD3-induced stimulation of naive CD4+ and CD8+ T cells was critically dependent on the expression of Fc,R on 80/1 DC and that the requirement for co-stimulation depends on the intensity of T-cell receptor signalling. [source] Microbiological, immunological and genetic factors in family members with periodontitis as a manifestation of systemic disease, associated with hematological disordersJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2002Mitsugi Okada The microflora, immunological profiles of host defence functions, and human leukocyte antigen (HLA) findings are reported for a mother, son and daughter who were diagnosed as having ,periodontitis as a manifestation of systemic diseases, associated with hematological disorders'. Examinations were made of the bacterial flora from the periodontal pocket, neutrophil chemotaxis, neutrophil phagocytosis, and the genotypes (DQB1) and serotypes (DR locus) of HLA class II antigens. Phenotypic analyses of the peripheral lymphocytes were also conducted. The subgingival microflora from the mother was dominated by Gram-negative rods, especially Porphyromonas endodontalis, Prevotella intermedia/Prevotella nigrescens and Fusobacterium nucleatum. Subgingival microflora samples from the son and daughter were dominated by Gram-positive cocci and Gram-positive rods. Through the use of polymerase chain reaction, Campylobacter rectus and Capnocytophaga gingivalis were detected in all subjects, whereas Porphyromonas gingivalis, P. intermedia, and Treponema denticola were not detected in any subjects. All three subjects showed a remarkable level of depressed neutrophil chemotaxis to N-formyl-methionyl-leucyl-phenylalanine, although their phagocyte function levels were normal, in comparison to healthy control subjects. Each subject had the same genotype, HLA-DQB1*0601, while the mother had HLA-DR2 and HLA-DR8, and the son and daughter had HLA-DR2 only. In summary, the members of this family showed a similar predisposition to periodontitis with regard to certain host defence functions. It is suggested that the depressed neutrophil chemotaxis that was identified here could be a significant risk factor for periodontitis in this family. [source] Reactive changes of interstitial glia and pinealocytes in the rat pineal gland challenged with cell wall components from gram-positive and -negative bacteriaJOURNAL OF PINEAL RESEARCH, Issue 1 2005Ya Fen Jiang-Shieh Abstract:, Lipopolysaccharide (LPS), the major proinflammatory component of gram-negative bacteria, is well known to induce sepsis and microglial activation in the CNS. On the contrary, the effect of products from gram-positive bacteria especially in areas devoid of blood,brain barrier remains to be explored. In the present study, a panel of antibodies, namely, OX-6, OX-42 and ED-1 was used to study the response of microglia/macrophages in the pineal gland of rats given an intravenous LPS or lipoteichoic acid (LTA). These antibodies recognize MHC class II antigens, complement type 3 receptors and unknown lysosomal proteins in macrophages, respectively. In rats given LPS (50 ,g/kg) injection and killed 48 h later, the cell density and immunoexpression of OX-6, OX-42 and ED-1 in pineal microglia/macrophages were markedly increased. In rats receiving a high dose (20 mg/kg) of LTA, OX-42 and OX-6, immunoreactivities in pineal microglia/macrophages were also enhanced, but that of ED-1 was not. In addition, both bacterial toxins induced an increase in astrocytic profiles labelled by glial fibrillary acid protein. An interesting feature following LPS or LTA treatment was the lowering effect on serum melatonin, enhanced serotonin immunolabelling and cellular vacuolation as studied by electron microscopy in pinealocytes. The LPS- or LTA-induced vacuoles appeared to originate from the granular endoplasmic reticulum as well as the Golgi saccules. The present results suggest that LPS and LTA could induce immune responses of microglia/macrophages and astroglial activation in the pineal gland. Furthermore, the metabolic and secretory activity of pinealocytes was modified by products from both gram-positive and -negative bacteria. [source] Autoimmunity as an aetiological factor in vitiligoJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2007N Rezaei Abstract Vitiligo is a common dermatological disorder characterized by the presence on the skin of depigmented macules resulting from the destruction of cutaneous melanocytes. Autoimmunity is an important hypothesis with regard to vitiligo aetiology and the evidence for autoimmune responses being involved in the pathogenesis of this disorder will be discussed in the present review. All immune system compartments, including innate and adaptive immunity have been implicated in vitiligo development. Particularly relevant are autoantibodies and autoreactive T cells in vitiligo patients that have cytotoxic effects upon pigment cells. Furthermore, predisposition to vitiligo appears to be associated with certain alleles of the major histocompatibility complex class II antigens as well as with other autoimmune-susceptibility genes. Moreover, the association of vitiligo with autoimmune disorders, the animal models of the disease, and the positive response to immunosuppressive therapeutic agents emphasize the role of autoimmunity in the development of this disorder. [source] Autoimmune hepatitis after liver transplantation and other lessons of self-intoleranceLIVER TRANSPLANTATION, Issue 6 2002Albert J. Czaja MD Autoimmune hepatitis has been described as recurrent or de novo disease after transplantation. The legitimacy of these diagnoses and the bases for their occurrence are unknown. To better understand these aspects of allograft dysfunction, the purported pathogenic mechanisms of classical autoimmune hepatitis were reviewed and extrapolated to recurrent and de novo disease after transplantation. Loss of self-tolerance may relate to defects in the negative selection of autoreactive immunocytes and the clonal expansion of promiscuous lymphocytes that are cross-reactive to homologous antigens (molecular mimicry). Repopulation of the allograft with recipient antigen-presenting cells and the presence of primed promiscuous cytotoxic T cells within the recipient are likely factors for recurrent disease. Targets may be the same peptides that triggered the original disease, donor-derived class II antigens of the major histocompatibility complex, or homologous antigens associated with unidentified hepatotrophic viruses. De novo disease is probably due to similar mechanisms, but its predilection for children suggests that thymic dysfunction associated with cyclosporine treatment may be a factor. Corticosteroid therapy is effective in each condition. In conclusion, recurrent and de novo autoimmune hepatitis after transplantation are examples of self-intolerance. The mechanisms that perturb immunologic homeostasis in this human model of the classical disease must be studied more rigorously. [source] Evidence for Humoral Rejection of a Pancreatic Islet Graft and Rescue with Rituximab and IV Immunoglobulin TherapyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2009L. Kessler We describe the decline in islet function, in relation to HLA sensitization, in an islet transplant recipient and the recovery of this function after treatment with anti-CD20 monoclonal antibody and IV immunoglobulins. A 51-year-old woman with type 1 diabetes received one intraportal islet infusion. Following this transplantation, she became insulin independent. A search for HLA antibodies by using an ELISA technique remained consistently negative for HLA class I and II. It was only 2 years after the islet transplantation that this search became positive against class II antigens, reaching a peak of reactivity concomitantly with the appearance of a deterioration of glucose control requiring low-dose insulin therapy. Luminex® screening and single-antigen assays then revealed the presence of both nondonor-specific and donor-specific antibodies against HLA class II molecules. This immunization, already present in the pretransplant serum, had increased during the 6 months preceding the clinical deterioration. Since these data nevertheless pointed to antibody-mediated rejection of the islet allograft, treatment with anti-CD20 monoclonal antibody and IV immunoglobulins was initiated. One month later, the search by ELISA for antibodies against HLA class II antigens became negative, the Luminex® tests normalizing more gradually. As the result of an improvement in glucose control, the patient was again insulin-free. [source] Post-transplant reactivation of hepatitis C virus: lymphocyte infiltration and the expression of adhesion molecules and their ligands in liver allografts,APMIS, Issue 4 2006KATRI LIPSON Hepatitis C virus (HCV) recurrence after liver transplantation has been associated with chronic rejection. Biopsies from 10 patients with post-transplant HCV were examined for expression of adhesion molecules ICAM-1, VCAM-1, and ELAM-1, number of lymphocytes positive for their ligands LFA-1, VLA-4, and SLeX, and activation markers MHC class II antigens and IL2-R by immunohistochemistry. The phenotypes of the graft-infiltrating lymphocytes were determined. Results were compared to those for patients with normal graft function or rejection. Five recipients with HCV reactivation and one with de novo HCV had a biopsy available showing induction of ICAM-1 in sinusoidal endothelium (p<0.05) and hepatocytes (p<0.01), and Class II antigens in hepatocytes (p<0.01), compared to normal controls. Lymphocytes in the graft infiltrate expressed LFA-1, VLA-4, and Class II antigens, but IL2-R was not significantly expressed. CD3+, CD4+, and CD8+ cells were observed. In our study, HCV recurrence was not associated with acute or chronic rejection, and the inflammation was due to the viral infection. [source] Anti-topoisomerase II , autoantibodies in systemic sclerosis,association with pulmonary hypertension and HLA-B35CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2000B. Grigolo We have previously detected autoantibodies against topoisomerase II , (anti-topo II ,) in sera from patients with idiopathic pulmonary fibrosis. To determine whether anti-topo II , is also present in systemic sclerosis (SSc) patients with pulmonary involvement, we screened sera from 92 patients and 34 healthy controls. Presence of anti-topo II , was investigated with respect to clinical and serological features, including the frequencies of HLA class I and II alleles. Anti-topo II , was detected in 20/92 (21.7%) patients. No association was found with either anti-topoisomerase I (Scl-70 or anti-topo I) or anti-centromere antibodies. However, anti-topo II , was associated with the presence of pulmonary hypertension (PHT) (as opposed to pulmonary fibrosis), and with a decrease of carbon monoxide diffusing capacity. Anti-topo II , was strongly associated with the presence of the class I antigen HLA-B35. No significant association was found with HLA class II antigens. HLA-B35 also turned out to be associated with the presence of PHT. These results indicate that in SSc patients, the presence of anti-topo II , is associated with PHT, and that the simultaneous presence of HLA-B35 seems to add to the risk of developing PHT. [source] | |||||||||||||||||||||||||