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ABSTRACT: Background
Autophagy is an important mechanism for promoting Mycobacterium clearance from macrophages. Pathogenic and non-pathogenic mycobacterium can activate the mTOR pathway while simultaneously inducing autophagy. M. tuberculosis and M. bovis BCG inhibit autophagy and favor intracellular bacteria survival.Results
We observed that pre-infection of live or heat-killed BCG could prevent autophagy induced by pharmacological activators or M. smegmatis, a strong autophagy-inducing mycobacterium. BCG-derived lipids are responsible for autophagy inhibition. However, post-infection with BCG could not stop the autophagy initiated by M. smegmatis, which increases further autophagy induction and mycobacteria clearance. Coinfection with BCG and heat killed M. smegmatis enhanced antigen specific CD4+ T cell responses and reduced mycobacterial survival.Conclusion
These results suggest that autophagy-inducing M. smegmatis could be used to promote better innate and consequential adaptive immune responses, improving BCG vaccine efficacy.
SUBMITTER: Gonzalez-Orozco M
PROVIDER: S-EPMC9472362 | biostudies-literature | 2022 Sep
REPOSITORIES: biostudies-literature
Gonzalez-Orozco Maria M Strong Emily J EJ Paroha Ruchi R Lee Sunhee S
BMC immunology 20220914 1
<h4>Background</h4>Autophagy is an important mechanism for promoting Mycobacterium clearance from macrophages. Pathogenic and non-pathogenic mycobacterium can activate the mTOR pathway while simultaneously inducing autophagy. M. tuberculosis and M. bovis BCG inhibit autophagy and favor intracellular bacteria survival.<h4>Results</h4>We observed that pre-infection of live or heat-killed BCG could prevent autophagy induced by pharmacological activators or M. smegmatis, a strong autophagy-inducing ...[more]