Optineurin-deficiency Collapses the Host Endolysosomal Network and Impairs Xenophagy to Accelerate Mycobacterium tuberculosis Growth

Optineurin is a selective autophagy receptor that targets pathogens and modulates immune signaling, yet its precise structural mechanism during Mtb infection remains poorly defined. Here, we show that while Optineurin-deficiency spares the global host transcriptomic response to infection, it collapses the host endolysosomal network, decreasing LAMP1⁺ and LysoTracker⁺ reserves by half.

Multi-dose bafilomycin A1 flux assays demonstrated that this structural depletion selectively blocks the dynamic, directional trafficking and functional delivery of autophagosomes to the pathogen, significantly reducing Mtb-DQ-BSA colocalization. Genetic complementation restored bacterial restriction in a manner dependent on three phosphosites (Ser187, Ser530, and the uncharacterized Ser556). In the context of reduced autophagic containment and increased Mtb replication, Optineurin-deficiency accelerated necrotic-like host cell death.