CD8+T lymphocytes protect SCID mice against Encephalitozoon cuniculi infection

Microsporidia are obligate intracellular parasites that cause opportunistic infections in immunocompromised patients. The role of two main T cell subs ets in anti-microsporidial immunity has been studied using an Encephalitozo on cuniculi-severe combined immunodeficient (SCID) mouse model. Whereas SCI D mice reconstituted with CD4 + T lymphocyte-depleted naive BALB/c splenocy tes resolved the infection, adoptive transfer of CD8 + T cell-depleted sple nocytes failed to protect the animals against a lethal E. cuniculi infectio n. Splenocytes from E, cuniculi-immune mice specifically killed syngeneic i nfected macrophages in a short-term Cr-51-release assay. These results sugg est the crucial role of cytotoxic T lymphocytes in the protection against E . cuniculi infection. (C) 2001 Australian Society for Parasitology Inc. Pub lished by Elsevier Science Ltd. All rights reserved.