Leishmania sp: Comparative study with Toxoplasma gondii and Trypanosoma cruzi in their ability to initialize IL-12 and IFN-g synthesis

Oliveira, M. A. P., Santiago, H. C., Lisboa, C. R., Ceravollo, I. P., Trinc hieri, G., Gazzinelli, R. T, and Vieira, L,. Q. 1000. Leishmania sp: Compar ative study with Toxoplasma gondii and Trypanosoma cruzi in their ability t o initialize IL-12 and IFN-gamma synthesis. Experimental Parasitology 95, 9 6-105. We compared in vitro and in vivo induction of IL-12 (p40) and IFN-ga mma by mouse cells stimulated with Toxoplasma gondii, Trypanosoma cruzi, an d different species of Leishmamia. Spleen cells cultured in vitro with T. c ruzi or T. gondii, but not with Leishmania produced IL-12 (p40) and IFN-gam ma. Accordingly, IL-12 (p30) was produced by macrophages stimulated in vitr o with live T.cruzi or T. gondii or membrane glycoconjugates obtained from trypomastigotes or tachyzoites. No IL-12 production was detected when macro phages were stimulated with live parasites or glycoconjugates from Leishman ia, regardless of priming with IFN-gamma. In vivo, only T. cruzi and T. gon dii induced the synthesis of IL-12 and IFN-gamma by mouse spleen cells afte r intraperitoneal injection of parasites. When injected subcutaneously, liv e Leishmania sp. induced IL-12 (p40) and IFN-gamma production by draining l ymph node cells, albeit the levels were slightly lower than those induced b y infection with T. gondii or T. cruzi using the same route. Together our r esults indicate that under different conditions, the intracellular protozoa 7 gondii and 7 cruzi are more potent stimulators of IL-12 and IFN-gamma sy nthesis by host immune cells than parasites of the genus Leishmania. (C) 20 00 Academic Press.