Phenotypic characterization of testicular immune cells expressing immune checkpoint molecules in wild-type and pituitary adenylate cyclase-activating polypeptide-deficient mice.

We hypothesize that these local changes may result in an immune activation with disturbed testicular immunoregulation in PACAP KO mice; however, determining the exact function requires further investigations. Our data further support the view that besides a systemic immune tolerance, localized active immunosuppression is involved in the regulation of testicular immune privilege.