Inherited maternal memory T cells protect offspring from respiratory viral infection through disease tolerance

Maternal immune transfer offers a potent early-life protective mechanism against infection, though the specific factors contributing to this protection are not fully understood. Researchers have now identified that maternal memory T cells are both essential and adequate to safeguard offspring from lethal respiratory infections. This protective effect operates independently of maternal antibodies and the offspring's own T cell responses, relying instead on IL-10 produced by the maternal T cells.

By transferring these protective maternal T cells to offspring, researchers observed a reduction in inflammatory responses and lung tissue damage, while viral loads remained unchanged. This indicates that maternal memory T cells directly inhibit pathogenic innate inflammatory responses to maintain offspring health. Notably, maternal vaccination also conferred similar protection to offspring in a T cell-dependent manner.

These findings demonstrate that maternal antigen-specific T cell transfer serves as an additional immunological defense mechanism to protect offspring from pathogens that may evade maternal antibodies. The implications of these findings are significant, as they suggest that maternal vaccination strategies could be optimized to harness this complementary defense mechanism, offering broad benefits for maternal and offspring health.