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Biomedical subjects

J Chiba

Publications and source records attributed to J Chiba.

At least 181 records · Page 10Linked to original sources

Autoimmune encephalomyelitis: simultaneous identification of T and B cells in the target organ.

Monoclonal antibodies to guinea pig T cells and antibodies to guinea pig immunoglobulin G were used in immunofluorescence studies to identify T and B cells in central nervous system tissue from guinea pigs with acute autoimmune encephalomyelitis. T cells appeared before B cells and were distributed within the white matter parenchyma, while B cells remained in perivascular spaces.

Animals↗

Monoclonal antibodies to guinea pig Ia antigens. I. Production, serologic, and immunochemical characterization.

Xenogeneic antibodies to guinea pig Ia antigens were produced by application of the hybridoma technique. BALB/c mice were immunized with the Ia-positive B cell leukemia line EN-L2C of strain 2 guinea pigs, and the spleen cells were fused to the mouse myeloma line NS-1. Culture supernatants of hybrids growing in the selective HAT medium were screened in a binding assay, and hybrids selectively reactive with EN-L2C but not with its Ia-negative variant BZ-L2C were cloned. Ascitic fluid was produced and used as a source of antibody. Four independently derived antibodies proved to be specific for Ia antigens. Two of the antibodies (25E3 and 25E11) seemed to recognize alloantigenic determinants on strain 2 Ia antigens in that they bound only to the cells of strain 2 but not to the cells of strain 13 animals. Two other antibodies (22C4 and 27E7) were found to react with both strain 2 and strain 13 cells, and immunoprecipitation experiments revealed that these antibodies were directed to common determinants shared between certain strain 2 and strain 13 Ia antigens. All antibodies were cytotoxic in the presence of complement for EN-L2C (but not for BZ-L2C) leukemia cells and for lymph node, spleen, peritoneal exudate cells, thymocytes, and purified T cells of strain 2 guinea pigs. In addition, 22C4 was cytolytic for cells of both strains. These results indicate that antibodies can be obtained through the hybridoma technique that are able to distinguish different determinants on Ia antigen molecules of te guinea pig. These antibodies should provide a useful tool for further study of the role of Ia antigens in cellular interaction and Ia-Ir gene function.

Animals↗

Allorestriction and xenorestriction phenomena in the induction of delayed-type hypersensitivity (DTH) responses in the guinea pig against azobenzenearsonate- (ABA) modified peritoneal exudate cells.

The role of MHC products in the induction of DTH responses Ia antigens play a crucial role in these cells in the recognition of ABA determinants by lymphocytes. Second, JY-1 guinea pigs were employed as responder animals. A clear allorestriction phenomenon was observed again when weakly modified ABA-PEC were used. On the other hand, the allorestriction phenomenon was apparently abrogated when heavily modified ABA-PEC were employed: allogeneic as well as syngeneic ABA-PEC induced strong and comparable DTH responses. Even in this condition, xenogeneic (mouse) ABA-PEC were barely immunogeneic, On the basis of these observations, the cross-reactivity of Ia antigens in the conjunctive recognition of haptenic determinants by T cells is discussed.

Animals↗