Perturbation of the Myeloid Compartment in Human Tuberculosis

PELLEGRINI J; CIALLELLA, LM; GARCIA V; MORELLI, MP; MARTINENA C.; PALMERO, DJ; AMIANO N; MARTIN C; LEVI A; TATEOSIAN NL

Virtual

Simposio; Myeloid Cells and Innate Immunity in Solid Tumors; 2020

Keystone

Alterations of myeloid cell populations have been reported in patients with tuberculosis (TB). However, little is known about how these cells are affected by the immunological status of TB patients. Circulating monocytes are classified into classical (CD14+CD16-) and atipic monocytes (CD14+CD16+) and the classical monocytes also contain monocytic myeloid-derived suppressor cells (M-MDSC). The aim of this study was to evaluate the perturbation of the myeloid compartment in TB. Blood mononuclear cells from TB patients at various times of anti-TB treatment, and healthydonor subjects (HD), were stained for monocyte (CD14 CD16) and for MDSC (CD14 CD11b HLA-DR CD15) populations and then analyzed by flow cytometry. TB subjects were classified as High (HR) and Low (LR) Responder according to previously establish criteria. We could observe that TB patients present higher percentage of non-classical monocytes (CD14+CD16+). Nevertheless, this increase was observed only TB LR population. Moreover, MDSC cells were increased in TB patients compare to HD, and the frequency of M-MDSC correlated with IFN-γ levels measured after Mtb-antigen stimulation. Furthermore, TB LR individuals presented the highest % of M-MDSC. On the other hand, the increase in G-MDSC percentage was observed in TB HR. Normal levels of CD14+CD16+ cells and M-MDSC were restored after first 14 days of anti-TB treatment. Conclusion: Immunological status of TB patients determinates the frequency and profile of monocytes and MDSC. The recovery of a normal % of these cell populations after 14 days of anti-TB treatment indicates that the frequency of monocyte and MDSCs would be related to the evolution of the disease.