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PubMedDate not supplied

Characterization of human heart-infiltrating cells after transplantation. VI. Differences in the cytokines produced by individual CD4+ cloned T-cell lines with apparently identical antiidiotype-like reactivity.

Studies of cultures and cloned T-cell lines from mononuclear cell infiltrates in cardiac biopsy specimens have provided a unique resource to study the cellular basis of human organ allograft rejection. Our laboratory has previously shown that biopsy specimens placed on autologous donor MHC-class-II-specific cloned T-cell lines from previous cardiac biopsies led to the isolation of cloned T-cell lines, which appeared to be functionally "antiidiotypic" in nature. Detailed functional analysis of such CD4+ individual antiidiotype-reactive cloned T-cell lines revealed that although some augmented the proliferative response of autologous idiotype-bearing cloned T-cell lines against donor stimulator cells, others markedly suppressed the proliferative response; thus, although each of these antiidiotype-like reactive cloned T-cell lines appears to specifically react with the same idiotype-bearing donor MHC-class-II-specific cloned T-cell line, they were functionally heterogeneous. Analysis of cytokines secreted by these individual clones showed that the antiidiotype-reactive cloned T-cell lines that suppressed the response of idiotype-bearing cells appear to secrete predominantly interferon gamma, whereas those antiidiotype-reactive cloned T-cell lines that augmented the response do not secrete interferon gamma but secrete interleukin-2, -4, and -6. These preliminary data suggest that differences in the predominant cytokines secreted by these individual antiidiotype-reactive cloned T-cell lines may account for their functional differences.

Antibodies, Anti-Idiotypic↗

PubMedDate not supplied

Cellular and molecular mechanisms of human cardiac myocyte injury after transplantation.

BACKGROUND: Fetal human cardiac myocytes or a cell line derived from fetal human cardiac myocytes, termed W1, even after experimental induction of "normal" levels of major histocompatibility complex class I and II antigens, fail to induce the activation of primary allogeneic responses. Therefore, our laboratory has investigated the ability of such MHC-expressing cardiac myocytes to induce secondary alloproliferative responses or to serve as target cells for cytotoxic T lymphocytes. METHODS: Cloned CD4+ and CD8+ T-cell lines having specificity for major histocompatibility complex class I and II molecules expressed by the fetal human cardiac myocytes and the W1 cell line were used in standard proliferation and cytotoxicity assays. RESULTS: Our data show that none of the 19 HLA-DR3 (beta 1 0301)- or HLA-DR15 (beta 1 1501)-specific CD4+ cloned T-cell lines reacted with HLA-DR3- or DR15-expressing W1 or fetal human cardiac myocytes. However, these CD4+ T cells did react, as expected, with similar HLA-DR3/DR15-expressing homozygous typing cells. Of the 16 cloned CD8+ cytotoxic T lymphocytes with specificity for HLA-A2 and the 12 with specificity for HLA-A1, only two of each showed weak cytotoxicity against interferon gamma-pretreated HLA-A2 and A1-expressing W1 and fetal human cardiac myocytes, respectively. Each cloned cytotoxic T lymphocytes line, however, was very effective against HLA-A2 and A1-expressing homozygous typing cells. Although the IFN-gamma-induced W1 and fetal human cardiac myocytes were not susceptible to cytotoxic T lymphocytes-mediated lysis, they were capable of inhibiting specific cytotoxic T lymphocytes function as defined by cold target inhibition studies. CONCLUSIONS: These data suggest that peptide-allo major histocompatibility complex presented by human cardiomyocytes is recognized by T cells and the these lymphocyte/myocyte interactions lead to immunologic ignorance.

CD4-Positive T-Lymphocytes↗