Testicular immune privilege: A recently discovered domain of collectins

Mammalian testis represents an immune privileged site where antigen specific adaptive immunity is suppressed to protect auto-antigenic developing spermatozoa. Effective regulation of autoimmune reactions against spermatogenic antigens and inflammatory immune responses against pathogens is critical to protect male fertility. Pattern recognition proteins Surfactant Protein-A (SP-A), Surfactant Protein-D (SP-D) and Mannan Binding Lectin (MBL) are known to regulate inflammatory immune responses, modulate the activity of other immune cells and restore immune homeostasis in the lung. In view of their immunomodulatory functions, various studies have explored the expression, regulation and plausible contribution of these collectins to testicular immune privilege. The present chapter below summarizes the available findings in the field.