Defective T-cell surface antigen expression after mitogen stimulation. An index of lymphocyte dysfunction after...

Murine spleen T-cell activation in lectin-stimulated cultures after 25% body surface area burn injury or hind-limb amputation was studied by measuring the temporal expression of cell surface markers using monoclonal antibodies and two-color flow cytometry. Lymphocyte activation has been shown to be accompanied by the appearance of new surface antigens, including Interleukin-2 (IL-2) deceptor (IL-2R) and Ia, and emergence of cells that coexpress helper (Th) and suppressor (Ts) surface markers. IL-2R has been shown to appear early on stimulated cells, before DNA synthesis, whereas Ia appears later. Surface markers (L3T4, Lyt2, Ia, and IL-2R) were analyzed at time 0 and after 24, 48, and 72 hours of mitogen-stimulated culture. The appearance of IL-2R and Ia on Th (L3T4+) and Ts (Lyt-2+) populations was markedly depressed after burn injury, but minimal changes were seen after musculoskeletal injury. In addition, coexpression of L3T4/Lyt2 antigens was markedly reduced in burn-derived cells. Serum from burn-injured animals caused depression of surface antigen expression by stimulated normal cells. Recombinant IL-2, when added to burn-derived cell cultures, did not increase expression of these surface markers during culture, nor did it improve proliferation.