The impacts of chronic infections on shaping cellular senescence

Cellular senescence is a fundamental biological process characterized by stable cell cycle arrest, genomic instability, and the acquisition of a proinflammatory secretory phenotype. While senescence is traditionally associated with aging, growing evidence reveals that chronic infections such as viral, bacterial, and protozoan parasites can serve as powerful inducers of senescence, contributing to premature aging and long-term tissue damage. This review explores the diverse mechanisms by which persistent pathogens trigger or sustain senescence in host cells. We highlight how these chronic infections manipulate host DNA repair, mitochondrial dynamics, telomere maintenance, oxidative stress, and immune function to promote senescence and immunosenescence. Emerging findings also reveal how pathogens hijack the host cellular machinery to induce senescence across various tissue types. In many cases, senescence not only enables pathogen persistence but also drives pathological outcomes such as fibrosis, neurodegeneration, cardiomyopathy, and immune exhaustion. Collectively, this emerging evidence highlights a unifying strategy among diverse pathogens: the exploitation of cellular senescence to support chronic infection and promote disease. Understanding how infectious agents drive senescence offers new insights into age-related pathologies and highlights potential therapeutic targets, such as senolytic and senomorphic agents, to mitigate the long-term impacts of chronic infections.