Decreased interleukin-2 responsiveness in leukocytes from Trypanosoma brucei-infected mice.
Immunosuppression with respect to those inducible processes which regulate lymphocyte mitogenesis was examined in experimental trypanosomiasis. Splenic leukocytes from Trypanosoma brucei-infected mice showed a decreased proliferative response to the T-cell mitogen concanavalin A. Activated cells secreted normal levels of the endogenous T-cell proliferative signal interleukin-2 (IL-2) and expressed high-affinity IL-2 receptors. However, the ability of activated cells to proliferate in response to exogenous IL-2 was inhibited. These results indicate an impairment of processes which occur after IL-2-receptor binding during lymphocyte mitogenesis. Furthermore, these data indicate that expression of high-affinity IL-2 receptors does not necessarily correlate with an ability to respond to IL-2.
D000818:Animals; D003208:Concanavalin A; D007165:Immunosuppression Therapy; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D014346:Trypanosoma brucei brucei / Q000276:immunology; D014353:Trypanosomiasis, African / Q000276:immunology*
D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A