Interleukin-2 receptors in experimental Chagas' disease.
Mammals infected with the protozoan parasite Trypanosoma cruzi develop suppressed cellular and humoral immune responses. This immunosuppression has been correlated with reduced T-cell responses involving deficient interleukin-2 (IL-2) production and is apparently mediated primarily by suppressor macrophages. Various forms of immunosuppression in other systems have been associated with increased levels of soluble IL-2 receptors (sIL-2R), and in the present study levels of sIL-2R in the sera of T. cruzi-infected mice during the course of infection were examined in enzyme-linked immunosorbent assays. It was found that serum levels of sIL-2R were elevated only during the third week of acute infection, a time of intense immunosuppression. In addition, IL-2R on the surface of T cells were examined by flow cytometric analyses to determine whether there is an alteration in the number of IL-2R-positive cells and whether there is a change in expression of these receptors as infection progresses. The results revealed no significant change in the percentage of cells expressing IL-2R, nor did T cells become suppressed in their ability to express IL-2R in response to concanavalin A during the course of infection.
Pakianathan
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DR
Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109.
Kuhn
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RE
D000818:Animals; D014355:Chagas Disease / Q000276:immunology*; D005260:Female; D051379:Mice; D008809:Mice, Inbred C3H; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D013601:T-Lymphocytes / Q000737:chemistry
D015375:Receptors, Interleukin-2