Local Muñiz strain of Mycobacterium tuberculosis induces differential T cell responses in MDR-TB patients.

GEFFNER L; YOKOBORI N; BALBOA L; SCHIERLOH P; BASILE J; ROMERO M; ALEMÁN M; RITACCO V; GARCÍA A; VESCOVO M; CUFRÉ M; GONZÁLEZ MONTANER P; ABBATE E; SASIAIN MC; DE LA BARRERA S

Keystone, Colorado

Simposio; Tuberculosis: Biology, Pathology and Therapy; 2009

In Argentina multidrug-resistant tuberculosis (MDR-TB) outbreaks emerged among hospitalized patients with AIDS in the early 90’s and disseminated to the community. Several MDR strains responsible for clustered MDR-TB cases have been isolated, including Muñiz strain belonging to Haarlem family (M) which has high infectivity/virulence. It is known that different Mycobacterium tuberculosis (Mtb) strains operate different immune evasion strategies for their survival in the host which mainly depends on the virulence of the strain and the host immune responses. Thus, the aim of this work was to evaluate the cytokine profile and cytotoxic T lymphocyte (CTL) activity induced by M strain. Methods: PBMC were isolated from MDR-TB patients and PPD+ healthy volunteers (N). Cells were cultured for 5 days alone (C) or with heat-killed H37Rv (Rv) Mtb reference strain or M. Intracellular expression of IL-10, IL-4, IFN-γ and surface acquisition of CD107 were determined in CD4 and CD8 T cells by flow cytometry. Results: PBMC stimulation with Rv and M enhanced IL-10+ and IFN-γ+ expression on CD4+ and CD8+ T cells from MDR-TB and N (p