Immunomodulatory activity of 4-(Benzyloxy)phenol facilitates intracellular mycobacterial clearance through p53 mediated IL-35 signaling dependent JAK1/STAT3 pathway in human macrophages.

Publication date: Jun 26, 2025

Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis (TB), modulates host immune responses by regulating various cytokines. Precise regulation of these cytokines renders the host pathogen-free, whereas their dysregulation increases the susceptibility to infection. Hence, induction of host protective cytokines using immunomodulators to promote M. tuberculosis clearance has a rewarding impact in the context of TB treatment. This study explored the immunomodulatory activity of 4-(Benzyloxy)phenol (4-BOP) in mycobacteria infected differentiated THP-1 cells through IL-35 (an anti-inflammatory cytokine) production. Initially, we observed an increased mRNA and protein level expression of IL-35 and its cognate receptor upon 4-BOP treatment in mycobacteria-infected dTHP-1 cells. IL-35 receptor activation further led to phosphorylation of JAK1/STAT3, culminating in increased phagosome-lysosome fusion through elevation of intracellular Ca level. Blocking IL-35 receptors using siRNA-mediated approach against IL-12Rβ2 and gp130 or the JAK1/STAT3 associated signaling with specific inhibitors like Baricitinib and Stattic promoted the intracellular mycobacterial survival by compromising Ca-phagosome-lysosome fusion pathway. Further, we identified a direct regulatory role of p53 (known to be activated by 4-BOP) on IL-35 production, and inhibition of p53 using PFT-α surprisingly abrogated the IL-35 mediated signaling axis. Collectively, our results demonstrated a host defensive role of 4-BOP-induced Il-35 signaling in mycobacteria-infected dTHP-1 cells through the JAK1/STAT3 mediated Ca-phagosome-lysosome fusion pathway. These results suggest that 4-BOP may serve as a potent HDT candidate for regulating inflammation and enhancing host defense in TB infection.

Semantics

Original Article