LncSSBP1/FOXO3 axis modulates autophagy: a novel insight into bronchial epithelial cells defense against Talaromyces marneffei infection.

BACKGROUND

While autophagy is pivotal in antimicrobial defense, its regulatory role in Talaromyces marneffei (TM) infected bronchial epithelium remains elusive.

OBJECTIVE

To elucidate the impact of TM infection on autophagy in bronchial epithelial cells and to identify the key molecular regulators involved in this process.

METHODS

Primary computational screening identified core autophagy modulators. Autophagy flux was monitored through LC3B-II/P62 immunoblotting and transmission electron microscopy. Mechanistic validation was performed using siRNA-mediated FOXO3 silencing, lentivirus-mediated lncSSBP1 knockdown and overexpression cell models, combined with immunofluorescence staining for nuclear localization.

RESULTS

Bioinformatics analysis identified seven autophagy modulating effectors, with FOXO3 emerging as the central regulator. Quantitative proteomics revealed biphasic autophagic responses: initial LC3B-II accumulation with P62 degradation at 4h post-infection, followed by P62 rebound at 24h, indicating time-dependent flux impairment. FOXO3 was identified as a critical mediator of TM-induced autophagy. Furthermore, we identified a strong positive correlation between lncSSBP1 and FOXO3 expression, with lncSSBP1 overexpression enhancing FOXO3 levels and promoting autophagosome maturation.

CONCLUSION

This study uncovers a previously unrecognized lncRNA-mediated regulatory axis wherein lncSSBP1 orchestrates FOXO3-driven autophagy during TM infection. These results provide new insights into the molecular mechanisms of host-pathogen interactions.