Recombinant cysteine proteinase from Leishmania (Leishmania) chagasi implicated in human and dog T-cell responses

Abstract

High in vitro lymphoproliferative responses were induced in humans and dogs by a recombinant Leishmania (Leishmania) chagasi cysteine proteinase, with secretion of IFN-gamma in asymptomatic subjects or of IFN-gamma, interleukin 4 (IL-4), and IL-10 in oligosymptomatic subjects. In contrast, responses of symptomatic patients and dogs were lower, with production of IL-4 and IL-10.

FIG. 1.

Proliferative responses of PBMC recovered from normal, asymptomatic, oligosymptomatic, symptomatic, and treated humans (A) and dogs (B) in the presence of rLdccys1 and AM. Data are representative of three experiments and are shown as mean SI ± standard deviations. An SI of ≥2.0 was considered a positive response (P < 0.05).

FIG. 2.

NO production. PBMC isolated from human (A) and dog (B) blood were cultured for 72 h in the presence of 2.5 μg/ml rLdccys1, and NO was assayed in the cellular supernatants as described previously. Results are shown as the means ± standard deviations and are representative of three experiments.