RRC ID 89527
Author Shamskhou EA, Duffy FJ, Cross LM, Plumlee CR, Gern BH, Barrett HW, Diercks AH, Cohen SB, Sivakumar R, Aitchison JD, Ganusov VV, Urdahl KB, Gerner MY.
Title Monocytic niches escape T cell surveillance and promote Mycobacterium tuberculosis persistence in lymph nodes.
Journal Immunity
Abstract Lung-draining mediastinal lymph nodes (medLNs) are critical for Mycobacterium tuberculosis (Mtb) pathogenesis, serving both as sites of T cell priming and, paradoxically, reservoirs for long-term bacterial persistence. To understand this dichotomy, we examined myeloid and CD4+ T cell dynamics in medLNs after aerosol Mtb infection. Early bacterial dissemination occurred via monocytes and interleukin (IL)-12-producing conventional dendritic cells (cDCs), which initiated T helper 1 (Th1) cell priming within the T cell zone. Over time, cDC migration and T cell activation declined, and medLNs became dominated by heavily infected monocyte-derived aggregates that persisted into late infection. Despite inducing proinflammatory and bactericidal pathways, these aggregates escaped recognition by Mtb-specific T cells and failed to clear Mtb, thereby forming an immunologically "blind" niche. Bacille Calmette-Guérin (BCG) vaccination reduced Mtb burden and niche establishment without altering myeloid trafficking or T cell priming. Thus, Mtb persists in medLNs within monocytic niches, eliciting classical antimicrobial programs that are insufficient for sterilizing control.
Published 2026-6-23
DOI 10.1016/j.immuni.2026.05.017
PII S1074-7613(26)00228-1
PMID 42335893
Resource
Mice RBRC09485