Requirement of the Fas ligand-expressing luteal immune cells for regression of corpus luteum

Apoptosis in corpus luteum (CL) is induced by prolactin (PRL) in female rat s. PRL-induced apoptosis in CL is mediated by the Fas/Fas ligand (FasL) sys tem. The CL consists of steroidogenic and non-steroidogenic cells, includin g immunocytes. Fas mRNA mas detected only in the luteal steroidogenic cells , and Fast mRNA was expressed only by the non-steroidogenic CD3-positive lu teal immunocytes. Removing the luteal immune cells from the luteal cells in hibited PRL-induced luteal cell apoptosis effectively. Thus, FasL-expressin g non-steroidogenic luteal immunocytes are required for PRL-induced luteal cell apoptosis and heterogeneous induction of apoptosis by Fas/FasL in CL. (C) 2000 Federation of European Biochemical Societies.