Interleukin-2 stimulates resting human T lymphocytes' response to allogeneic, gamma interferon-treated keratinocytes.
In order to investigate the biologic significance of HLA-DR expression by human keratinocytes, we have examined the possibility that DR-positive keratinocytes become alloantigen presenting cells for resting T cells in the presence of interleukin-2. Using this system, gamma interferon-treated, DR-positive keratinocytes stimulate the proliferation of allogeneic, resting T cells approximately 3-fold whereas non-gamma interferon-treated, DR-negative keratinocytes do not. Because a monoclonal antibody against recombinant gamma interferon inhibits this proliferation, the stimulation is dependent on pre-incubation with gamma interferon. By contrast, since the stimulation is not inhibited by a monoclonal antibody against HLA-DR, it is not clear that the stimulation is due to class II antigen expression by keratinocytes. To rule out that gamma interferon increases the expression of class I antigens, leading to stimulation of resting T cells on that basis, we determined whether gamma interferon treatment enhances class I antigen expression by keratinocytes. The lymphokine treated cells did not demonstrate more class I antigen expression than untreated keratinocytes. Thus, the observed stimulation of allogeneic, resting T cells by gamma interferon-treated keratinocytes in the presence of IL-2 is not due to increased class I antigen expression but is due to other cell surface antigen(s) induced by recombinant gamma interferon treatment. These results suggest that gamma interferon-exposed keratinocytes in the presence of interleukin-2 may augment the activation of resting T lymphocytes and, in this manner, may contribute to cutaneous inflammation.
D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects* / Q000276:immunology; D006681:HLA-D Antigens / Q000096:biosynthesis*; D006684:HLA-DR Antigens / Q000096:biosynthesis* / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology*; D007518:Isoantibodies / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D011994:Recombinant Proteins / Q000494:pharmacology; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
D000911:Antibodies, Monoclonal; D006681:HLA-D Antigens; D006684:HLA-DR Antigens; D007376:Interleukin-2; D007518:Isoantibodies; D011994:Recombinant Proteins; D007371:Interferon-gamma