Splenic accumulation of PD-1+ TIGIT+ CD4+ T cells and elevated of IL1R2 expression suppress antibody production during aging

Aging populations and infectious diseases are posing increasingly significant global challenges. The the immune system’s changes, particularly in the spleen, are crucial for elderly individuals to combat infections. However, the underlying mechanism of aging changes in the spleen remains unclear. In this study, we observed that IgE and IgG1 production was suppressed following OVA stimulation in 18-month-old mice. Using CyTOF, we identified a notable accumulation of exhausted PD-1+TIGIT+CD4+ T cells in the spleens of aging individuals. These cells influenced B cells IgG1 production via the il1r2-CD40L pathway. Our findings revealed how immunity declines with age and offers specific targets for enhancing elderly immunity through nutritional interventions and vaccine development. The exhausted PD-1+TIGIT+CD4+ T cells detected by CyTOF detection were sorted and then subjected to transcriptome sequencing to discover differentially expressed genes and pathways that affect the immune response function.