The role of B cells in immune cell activation in polycystic ovary syndrome

Variations in B cell numbers are associated with polycystic ovary syndrome (PCOS) through unknown mechanisms. Here we demonstrate that B cells are not central mediators of PCOS pathology and that their frequencies are altered as a direct effect of androgen receptor activation. Hyperandrogenic women with PCOS have increased frequencies of age-associated double-negative B memory cells and increased levels of circulating immunoglobulin M (IgM). However, the transfer of serum IgG from women into wild-type female mice induces only an increase in body weight. Furthermore, RAG1 knock-out mice, which lack mature T- and B cells, fail to develop any PCOS-like phenotype. In wild-type mice, co-treatment with flutamide, an androgen receptor antagonist, prevents not only the development of a PCOS-like phenotype but also alterations of B cell frequencies induced by dihydrotestosterone (DHT). Finally, B cell-deficient mice, when exposed to DHT, are not protected from developing a PCOS-like phenotype. These results urge further studies on B cell functions and their effects on autoimmune comorbidities highly prevalent among women with PCOS. Summary Androgen receptor activation alters B cell frequencies and functionality as the transfer of human PCOS IgG increase weight in female mice. Lack of B cells does not protect from the development of a PCOS phenotype, suggesting an unrecognized role for B cells in PCOS autoimmune comorbidities. Graphical Abstract