Scientists discovered that fibroblasts, common tissue cells, become activated with age and drive inflammaging - the chronic low-grade inflammation linked to age-related diseases. These activated fibroblasts trigger a cascade involving immune cells that creates harmful granzyme K-positive T cells. These exhausted T cells form abnormal immune structures in tissues and increase susceptibility to lung injury and severe pneumonia, conditions that disproportionately affect older adults. The research provides the first structural explanation for how inflammaging develops at the tissue level, showing fibroblasts orchestrate complex immune changes that make aging bodies more vulnerable to disease.
