RNA-seq analysis of old versus young, male versus female, and naïve versus effector memory CD4+ T cells.

Impaired T cell immunity in the elderly increases mortality from infectious disease. The branching of Asparagine-linked glycans is a critical negative regulator of T cell immunity. We found that N-glycan branching increases with age in female > male, naïve > memory and CD4+ > CD8+ T cells, likely contributing to immunosenescence. To investigate the mechanisms driving these changes, we performed RNA-seq analysis on highly purified young and old naive (CD3+CD4+CD25-CD62L+CD44-) and effector memory (CD3+CD4+CD25-CD62L-CD44+) CD4+ T cells from male and female mice. Comparing young and old CD4+ TN cells, 158 and 192 differentially expressed genes (DEGs) were identified in females and males, respectively. Remarkably, only 44 of these overlapped between the sexes. There were no significant differences in gene expression of N-glycan branching enzymes or other relevant glycosylation genes. Among the 114 DEGs in female but not male CD4+ TN cells, four were within the IL-7 signaling pathway, a pathway previously implicated in regulating N-glycan branching. This included reduced expression of IL7Ra (CD127) and increased expression of Suppressor of cytokine signaling 1 (Socs1), Socs3, and Janus kinase 3 (Jak3). Other IL-7 signaling pathway genes were unchanged. Overall design: Examination of mRNA profiles from naïve (CD3+CD4+CD25-CD62L+CD44-) and effector memory (CD3+CD4+CD25-CD62L-CD44+) CD4+ T cells from young and aged female and male mice. Three biological replicates of each were analyzed for 24 total samples.