title: Alterations in cytotoxic and helper T cell function after infection of T cell clones with human T cell leukemia virus, type I.
abstract: HTLV-I is a transforming human retrovirus that is an etiologic agent of adult T cell leukemia/lymphoma. To investigate the effects of this virus on T cell functions, two OKT3+, OKT4+, OKT8- cytotoxic clones (8.7 and 8.8) specific for allogeneic cells bearing DPw2, a class II histocompatibility antigen, were studied before and after infection with HTLV-I. The clones retained cytotoxic function for up to 70 d after exposure to HTLV-I, even without subsequent antigenic stimulation, but then lost their cytotoxic activity. Prior to infection with HTLV-I, clone 8.8 also lysed OKT3 hybridoma cells; after infection, cytotoxic activity against these OKT3-antibody bearing cells was lost in parallel with the loss of activity against DPw2-bearing target cells. In addition, expression of T3 surface antigen by HTLV-I-infected 8.8 cells was decreased at a time when they lost their cytotoxic activity, possibly contributing to the loss of cytotoxic function. Finally, clone 8.8 could provide help for nonspecific IgG production by autologous B cells when stimulated with irradiated DPw2-bearing non-T cells. After infection with HTLV-I, this helper function became independent of DPw2-stimulation and persisted even when the cytotoxic activity was lost. An OKT4+ T cell clone thus could simultaneously manifest both cytotoxic and helper T cell activities, and these activities were differentially affected after HTLV-I infection.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D002999:Clone Cells; D004279:DNA, Viral / Q000032:analysis; D017977:Deltaretrovirus / Q000235:genetics; D015683:Gene Products, gag; D006680:HLA Antigens / Q000032:analysis; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D012192:Retroviridae Infections / Q000276:immunology*; D012191:Retroviridae Proteins / Q000032:analysis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D004279:DNA, Viral; D015683:Gene Products, gag; D006680:HLA Antigens; D007074:Immunoglobulin G; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D012191:Retroviridae Proteins