Multiple sclerosis (MS) is more prevalent in women, with a female-to-male ratio of 3:1. The molecular mechanisms driving this sex difference are still mostly unknown. MS results from immune dysfunctio Show more
Multiple sclerosis (MS) is more prevalent in women, with a female-to-male ratio of 3:1. The molecular mechanisms driving this sex difference are still mostly unknown. MS results from immune dysfunction, with an imbalance in effector and regulatory T cells. Among the latter, Type I regulatory T cells (Tr1) are dysfunctional in people with MS (pwMS), secreting less IL-10, a potent anti-inflammatory cytokine, than in healthy donors. Our objectives were to explore the effect of biological sex on Tr1 cell differentiation in healthy donors and pwMS. CD4 We found that healthy female Tr1 cells produce less IL-10 than male cells (16 women and 16 men, 18-45 years old, We demonstrate that sex influences IL-10 production by Tr1 cells via the PI3K pathway, potentially contributing to the greater susceptibility of women to MS. Furthermore, our data suggest that targeting PI3Kδ may represent a novel therapeutic strategy to boost IL-10 production in female pwMS. Show less