MODULATION OF THE AUTOPHAGY PROCESS BY IL-1BETA; DURING HUMAN ACTIVE TUBERCULOSIS

CANDELA MARTIN; MORELLI, MARÍA PAULA; DOMINGO J. PALMERO; VERONICA E GARCIA; , GARCÍA V.E

Simposio; Buenos Aires Research Conference on Autophagy and Vesicualr Trafficking, Mechanisms and Disease; 2023

Autophagy, an essential process that maintains cell homeostasis, is also an important protective mechanism against intracellular pathogens such as Mycobacterium tuberculosis (Mtb). Actually, it has been demonstrated that the induction of autophagy suppressed intracellular survival of Mtb. Interleukin 1β (IL-1β), a key mediator of the inflammatory response, is essential for human host-responses against microorganisms. Previously, we reported that IFNγ and IL-17A augmented autophagy in Mtb-infected monocytes from tuberculosis (TB) patients, in direct correlation with their immunological status. In fact, TB patients were classified as low and high responders (LR and HR, respectively) according to their immune responses to sonicated Mtb (Mtb-Ag). In this work, we investigated the role of IL-1β on the autophagy process in HR and LR TB patients with ultimate goal of elucidating if this cytokine could play a role in a host directed therapy against Mtb. We obtained monocytes were obtained from heparinized peripheral blood of TB patients and healthy donors (HD, control individuals) from the community. The cells were cultured at 2×106 cells/ml with an Mtb lysate (Mtb-Ag, 10μg/ml) in the presence or absence of IL-1β (10ng/ml). Flow cytometry, confocal microscopy and western blot were used to evaluate the autophagy levels by determining LC3 (the main marker of the autophagy process). Besides, to study the autophagic flux, Bafilomycin A1 (BafA1, 100nM) was added together with IL-1β and Mtb-Ag. Furthermore, to evaluate the effect of IL-1β on bacterial growth, monocytes were infected with H37Rv Mtb strain (MOI: 10) and after 2h of infection, cells were cultured ± IL-1β (10 ng/ml) or IL-1RA (500ng/ml, an antagonist of IL-1β receptor) for 96h. Cells were then washed and lysed to assay mycobacterial colony-forming units (CFU). P-values