Cell senescence emerges as a hallmark and therapeutic target of chronic intracellular infection

This study unveils how the intracellular pathogen Mycobacterium abscessus (Mab) reprograms alveolar macrophages towards a senescent state -a multifaced phenotype marked by proliferative arrest, distinctive morphological shifts, activation of DNA damage signalling cascade, and secretion of senescence-associated secretory phenotype (SASP) factors.

Mab-induced DNA damage emerged as the primary driver of senescence, while SASP secretion acts as a molecular broadcaster, propagating secondary senescence in neighbouring, uninfected cells through paracrine signalling. This cascading wave of amplified senescence underscores a detrimental effect on the tissue microenvironment, turning it into a chronic inflammatory niche that facilitates Mab persistence and immune evasion.