Perturbation of the Myeloid Compartment in Human Tuberculosis

PELLEGRINI, JOAQUIN M.; CIALLELA, LORENA; GARCIA VERONICA; AMIANO, NICOLÁS; MARTIN CANDELA; LEVI, NICOLÁS; TATEOSIAN, NANCY L; MORELLI, PAULA; MARTINENA CAMILA; PALMERO, DOMINGO

Simposio; Keystone eSymposia; 2020

Alterations of myeloid cell populations have been reported in patients withtuberculosis (TB). However, little is known about how these cells are affected by theimmunological status of TB patients. Circulating monocytes are classified into classical(CD14+CD16-) and atipic monocytes (CD14+CD16+) and the classical monocytes alsocontain monocytic myeloid-derived suppressor cells (M-MDSC). The aim of this studywas to evaluate the perturbation of the myeloid compartment in TB. Bloodmononuclear cells from TB patients at various times of anti-TB treatment, and healthydonor subjects (HD), were stained for monocyte (CD14 CD16) and for MDSC (CD14CD11b HLA-DR CD15) populations and then analyzed by flow cytometry. TB subjectswere classified as High (HR) and Low (LR) Responder according to previously establishcriteria. We could observe that TB patients present higher percentage of non-classicalmonocytes (CD14+CD16+). Nevertheless, this increase was observed only TB LRpopulation. Moreover, MDSC cells were increased in TB patients compare to HD, andthe frequency of M-MDSC correlated with IFN-γ levels measured after Mtb-antigenstimulation. Furthermore, TB LR individuals presented the highest % of M-MDSC. Onthe other hand, the increase in G-MDSC percentage was observed in TB HR. Normallevels of CD14+CD16+ cells and M-MDSC were restored after first 14 days of anti-TBtreatment. Conclusion: Immunological status of TB patients determinates thefrequency and profile of monocytes and MDSC. The recovery of a normal % of thesecell populations after 14 days of anti-TB treatment indicates that the frequency ofmonocyte and MDSCs would be related to the evolution of the disease.