Ia determinants on stimulated human T lymphocytes. Occurrence on mitogen- and antigen-activated T cells.
Human T-cell blasts were generated by stimulation with mitogens and antigens. A proportion of these blasts expressed Ia antigens detectable by immunofluorescence with both allo- and hetero-antiserums. The maximal expression of Ia antigens was delayed and usually occurred after the peak of blastogenesis. Among the three mitogens used, pokeweed mitogen (PWM) was most effective in giving a high percentage and intense Ia staining of T-cell blasts. Phytohemagglutinin and concanavalin A blasts gave weaker and lower percentages of Ia staining. Activation by alloantigens and soluble antigens such as tetanus toxoid and purified protein derivative resulted in Ia expression on T cells comparable to PWM stimulation. Depletion of Ia+ cells from freshly isolated T cells with anti-Ia and complement decreased subsequent Ia expression, suggesting that a proportion of Ia+ blasts were derived from Ia-bearing peripheral blood T cells. When the specificities of the Ia antigens on T-cell blasts were examined with alloantiserums, it was evident that the T blasts expressed similar HLA-DR determinants to those on B cells from the same donor; occasional minor differences between stimulated T cells and autologous B-cell lines or fresh B cells were encountered.
D002478:Cells, Cultured; D000939:Epitopes; D006801:Humans; D007106:Immune Sera; D007519:Isoantigens / Q000032:analysis*; D007959:Lymphocyte Culture Test, Mixed; D008934:Mitogens; D013601:T-Lymphocytes / Q000276:immunology*; D013745:Tetanus Toxoid
D000939:Epitopes; D007106:Immune Sera; D007519:Isoantigens; D008934:Mitogens; D013745:Tetanus Toxoid