title: HLA-DRw alloantigens can be detected on peripheral blood T lymphocytes.
abstract: Antisera detecting HLA-DRw antigens (human Ia-like) react in cytotoxicity assays with peripheral blood B cells and monocytes but not T lymphocytes. Antisera detecting DRw specificities were used in flow microfluorometry studies to determine whether T lymphocytes express these antigens in quantities not detected by cytotoxicity. Peripheral blood lymphocytes depleted of monocytes were incubated with DRw antisera, reacted with fluoresceinated goat anti-human IgG, and analyzed on the fluorescence-activated cell sorter (FACS). Anti-DRw sera were found to be reactive on all of the lymphocytes as evidenced by a positive fluorescence signal. The reactivity was specific in that only those sera that detected DRw antigens on B cells and monocytes were reactive with the total lymphocyte population from the same donor. Reactivity of the antisera was removed by absorbing the antiserum with monocyte/B cells and T cells from a donor with the same DRw antigen as that found on the target cell of the donor tested. The results demonstrate the presence of DRw antigens on resting peripheral blood T lymphocytes. The implications of quantitative differences in DRw antigen expression on lymphoid cells are discussed.
mesh_terms: D000042:Absorption; D001402:B-Lymphocytes / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D005470:Fluorometry; D000949:Histocompatibility Antigens Class II; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000949:Histocompatibility Antigens Class II; D007106:Immune Sera