Determination of the Frequency of Myeloid-derived Suppressor Cells during Human Active Tuberculosis

MORELLI M.P.; CASCO, NICOLÁS; GALLEGO CLAUDIO; TATEOSIAN NANCY; CASTELLO, FLORENCIA A.; AMIANO NICOLÁS; CASTAGNINO JORGE; GARCÍA, VERÓNICA; PELLEGRINI J.; CIALLELLA LORENA; PALMERO D.J.

Mar del Plata

Congreso; LXIII Reunión Anual de la Sociedad Argentina de Investigacion Clinica (SAIC); 2018

Sociedad Argentina de Investigacion Clinica

Tuberculosis (TB), together with HIV infection, is the leading cause of death from an infectious disease worldwide. In fact, Mycobacterium tuberculosis (Mtb) causes almost 10 million of new cases and 1.5 million deaths per year. Human myeloid-derived suppressor cells (MDSC) have been described as a group of immature myeloid cells which exert immunosuppressive action by inhibiting function of T lymphocytes. There are two different types of MDSC, as identified in studies in both mice and humans: granulocytic MDSC (g-MDSC) are morphologically and phenotypically similar to neutrophils, whereas monocytic MDSC (m-MDSC) are similar to monocytes. MDSCs display an immunosuppressive function during several pathological conditions such as cancer and hepatitis. MDSC-mediated suppression of host immunity during chronic inflammation is crucial for immune regulation and tolerance to limit immunopathology. Furthermore, the unfavorable effects of MDSCs are evident in tumor biology where they accumulate and suppress cytokines Th1 responses. Nevertheless, no evidence of a functional role for MDSCs in human TB exists. We hypothesized that patients with active TB would have higher frequencies of MDSCs compared to healthy control subjects. Therefore, the aim of this work was to study the expression of MDSCs during active TB.