Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Major histocompatibility complex class I-deficient islets from beta-2 microglobulin-deficient mice have been shown to have prolonged in vivo islet allograft survival. Additionally in vitro studies using the mixed lymphocyte islet coculture system have demonstrated a reduction in cytotoxic T lymphocyte activity against alloislets that have been pretreated with an antibody directed against MHC class I antigen. The clinical applicability of these findings are examined in this study, which evaluates the ability of MHC class I blocking antibody to prevent the in vivo destruction of alloislets. Recipients of allogenic islet transplants treated with phosphate-buffered saline or control F(ab')2 fragments rejected the transplanted alloislets in median times of 11.5 days and 11 days, respectively. Recipient mice treated with a monoclonal antibody or F(ab')2 fragments specific to the donor MHC class I antigen had significant prolongation in allograft survival (median allograft survival for both groups was 21 days) when compared with mice treated with PBS or control F(ab')2 fragment. These results demonstrate that treating recipients of alloislets with donor-specific MHC class I monoclonal antibody or the respective F(ab')2 fragments prolongs islet allograft survival. This confirms the importance of MHC class I antigen in the rejection of pancreatic islet allografts and suggests that blocking different domains on the MHC class I molecule could be used therapeutically in the protection of allografts from the immune system.
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PMID:Prolongation of in vivo mouse islet allograft survival by modulation of MHC class I antigen. 815 21

Heat shock proteins are recognized as significant participants in immune reactions. In this study, we have demonstrated that the cell surface presentation of MHC class I antigen was increased in tandem with increased heat shock protein 70 (HSP70) expression and the immunogenicity of rat T-9 glioma cells was enhanced by hyperthermia. T-9 cells showed growth inhibition for 24 h after the heat treatment at 43 degrees C for 1 h in vitro, but then resumed a normal growth rate. HSP70 expression reached a maximum at 24 h after heating. Flow cytometric analysis revealed a significant increase in MHC class I antigen on the surface of the heated cells. The augmentation of MHC class I surface expression started 24 h after heating and reached a maximum 48 h after heating. The expression of other immunologic mediators, such as intracellular adhesion molecule-1 (ICAM-1) and MHC class II antigens, did not increase. In an in vivo experiment using immunocompetent syngeneic rats (F344), growth of the heated T-9 cells, with augmentation of MHC class I antigen surface expression, was significantly inhibited, while the cells grew progressively in nude rats (F344/N Jcl-rnu). Furthermore, compared with lymphocytes from non-immunized (PBS only injection) rats or rats injected with non-heated T-9 cells, the splenic lymphocytes of the rats in which the heated T-9 cells were injected displayed specific cytotoxicity against T-9 cells. These results suggest that HSP70 is an important modulator of tumor cell immunogenicity, and that hyperthermic treatment of tumor cells can induce the host antitumor immunity via the expression of HSP70. These results may benefit further efforts on developing novel cancer immunotherapies based on hyperthermia.
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PMID:Augmentation of MHC class I antigen presentation via heat shock protein expression by hyperthermia. 1177 73

We evaluated recurrent NXS2 neuroblastoma tumors that developed following NK- or T-cell-mediated immunotherapy in tumor-bearing mice. Recurrent tumors developed following an NK-dependent antitumor response using a suboptimal dose of hu14.18-IL2, a humanized IL-2 immunocytokine targeted to the GD(2)-ganglioside. This treatment initially induced complete resolution of measurable tumor in the majority of mice, followed, however, by delayed tumor recurrence in some mice. These recurrent NXS2 tumors revealed markedly enhanced (> fivefold) MHC class I antigen expression when compared with NXS2 tumors growing in PBS-treated control mice. A similar level of enhanced MHC class I antigen-expression could be induced on NXS2 cells in vitro by culturing with interferon gamma, and was associated with reduced susceptibility to both NK-cell-mediated tumor cell lysis and antibody-dependent cellular cytotoxicity in vitro. In contrast, Flt3-ligand treatment of NXS2-bearing mice induced a protective T-cell-dependent antitumor memory response. Recurrent NXS2 tumors that developed following Flt3-L therapy revealed a decreased expression of MHC class I antigens. While NXS2 tumors are susceptible to in vivo destruction following either hu14.18-IL2 or Flt3-ligand immunotherapies, these results suggest that some tumor cells may be selected to survive and progress by expressing either higher or lower levels of MHC class I antigen in order to resist either NK- or T-cell-mediated antitumor responses, respectively.
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PMID:NXS2 murine neuroblastomas express increased levels of MHC class I antigens upon recurrence following NK-dependent immunotherapy. 1450 25