C5A modulates reactive oxygen species production induced by Mycobacterium tuberculosis on human monocytes

SABIO Y GARCÍA C; YOKOBORI N; BASILE J; LÓPEZ B; RITACCO V; DE LA BARRERA S; SASIAIN MC

Los Cocos, Córdoba

Congreso; LXI Reunión Anual de la Sociedad Argentina de Inmunología; 2013

Sociedad Argentina de Inmunología

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is capable of establishing a niche inside phagocytic cells, where it can survive and replicate. The progression of the infection mainly depends on the innate immune response. The complement system (C) is an important component of the innate immunity and it products are elevated in the tuberculous pleural fluids. Particularly, the C5a anaphylatoxin component precursor, C5, is involved in reactive oxygen species (ROS) production and Mtb killing in mouse macrophages. The aim of this work was to evaluate the effects of C5a in ROS production induced by Mtb on monocytes (Mo). Mo were purified from buffy coats of healthy donors by percoll gradient and subsequently stimulated with H37Rv or M gamma-irradiated strains at different Mtb:Mo ratio for 90 min (H37Rv and M) or not stimulated (control). C5a receptor (C5aR) on Mo was blocked (blk) or C5a was added at different times before or after stimulation with Mtb strains (C5a). ROS production was analyzed by DHR flow cytometry assay. The results demonstrated that 1) ROS production was induced by H37Rv above basal levels (p