CD11c+M1-like macrophages (MΦs) but not CD206+M2-like MΦ are involved in folliculogenesis in mice ovary

Macrophages (M Phi s) are involved in folliculogenesis and ovulation. However, it is unknown which type of M Phi, M1 or M2, plays a more essential role in the ovary. CD206 or CD11c diphtheria toxin receptor transgenic (DTR) mice, which enable depletion of CD206+ M2 M Phi s and CD11c+ M Phi or CD11c+ Dendritic cells (DCs), respectively, were used. Oocytes were used for in vitro fertilization and embryo transfer. In vitro fertilized embryos derived from M2 MF depleted oocytes were transferred to pseudo pregnant wild type mice. CD11c DTR mice were also used to investigate the role of CD11c cells, M1 M Phi and DCs in folliculogenesis. In WT mice, the proportion of CD206+ M2-like M Phi s was not increased in follicular induction, while that of CD11c+ M1-like MFs was increased. In CD206 DTR mice, folliculogenesis was normal and the ovulation number, fertilization rate, and implantation rate were similar to those in WT mice. In CD11c DTR mice, folliculogenesis was impaired with ovarian hemorrhage and the staining of platelet derived growth factor-receptor beta (PDGF-R beta), a marker of pericytes, and CD34, a marker of endothelial cells, was reduced. CD11c+ cells, M1 M Phi s or DCs, may be involved in folliculogenesis, while M2 M Phi s are not involved in folliculogenesis.