Mycobacterium tuberculosis Rv0158 negatively regulates the cGAS-STING pathway mediated type I IFN production and enhances intracellular survival.

BACKGROUND

Type I interferons (IFN) play an important role in the host defense against Mycobacterium tuberculosis (M. tb) infection and disease pathogenesis. Although M. tb has evolved several mechanisms to evade host immune surveillance, the mechanism used to regulate type I IFN expression remains unclear.

METHODS

In this study, genome-wide high-throughput loss-of-function screening was performed to screen M. tb determinants that regulate the Type I IFN pathway, and the role for M. tb Rv0158 in inhibiting type I IFN responses was identified in vitro and in vivo.

RESULTS

The M. tb coding protein Rv0158 was identified among many transposon (Tn) insertion mutants, which increased the expression of IFN-β and some pro-inflammatory cytokines. The results suggested that Rv0158 is associated with reduced STING protein levels and suppression of cGAS-STING-mediated innate immune responses, suggesting that Rv0158 may indirectly facilitate STING degradation or modulate its stability through host-interacting partners. Rv0158 also down-regulated the transcription of interferon-stimulated genes (ISGs) and increased the bacterial load in mice.

CONCLUSION

Overall, our finding identified a new bacterial factor Rv0158, these results reveal an important role for M. tb Rv0158 in inhibiting Type I IFN responses, which improves our understanding of the immune evasion mechanisms of M. tb.