title: Reactivity of HTLV-transformed human T-cell lines to MHC class II antigens.
abstract: T-cell lines established from individuals infected with human T-cell leukaemia virus (HTLV) or generated by co-cultivation of normal human T cells with HTLV-infected T-cells, express class II (HLA-D/DR or Ia) antigens of the major histocompatibility complex (MHC) and interleukin-2 (IL-2) receptors. Because the expression of these markers characterizes the differentiation of immunologically activated T cells, we have now explored the possibility that HTLV- infected T cells might be primed to autologous or allogeneic Ia antigens expressed by the infecting cells. Our studies on the capacity of HTLV-infected T cells to display responses on mixed lymphocyte culture indicate that such T cells as well as single-cell clones derived from them, react non-discriminatively to all known allelic variants of human HLA-D/DR antigens, including those expressed by the responding cells. This reaction is inhibited by antibody to human Ia and is not triggered by Ia-negative T-leukaemia cells. The structure recognized seems to be a common epitope determinant of human Ia antigens, as (HTLV-infected) T cells primed in vitro to one HLA-D/DR specificity display amplified responses to all other HLA-D/DR antigens. We therefore believe that autostimulation by a self-Ia determinant may trigger the clonal expansion of HTLV-infected T cells and potentiate autoimmune processes.
mesh_terms: D000911:Antibodies, Monoclonal; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002478:Cells, Cultured; D017977:Deltaretrovirus / Q000276:immunology*; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects / Q000528:radiation effects; D007959:Lymphocyte Culture Test, Mixed; D008285:Major Histocompatibility Complex; D012192:Retroviridae Infections / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D001973:Bromodeoxyuridine