I was reading about the Sertoli cells in the seminiferous tubules of the testes and it said that one of their roles was to protect the developing sperm cells from the male immune system. Why? Surely these cells have the same 'self' antigens as the rest of the cells in the body. Why do they need protecting?

One thing the Sertoli cells do is act as a blood-testis barrier preventing sperm-immune cell contact. I believe that spermatozoa themselves have immunosuppressive properties (e.g., maybe by producing anti-inflammatory cytokines). The developing sperm are immunogenic - I guess what is happening here is that spermatozoa are not produced until puberty which is long after the establishment of tolerance to self-antigens (breakdown of tolerance to self is one cause of autoimmune diseases).

The testis ‘immunological’ microenvironment does not always protect sperm against the male immune system since anti-sperm antibodies are not uncommon (e.g., prevalent in men with vasectomies) and can be one cause of infertility. According to one publication (see - http://molehr.oxfordjournals.org/content/13/7/437.long) there are at as many as 35 immunoreactive antigens in sperm from men with anti-sperm antibodies.

Last edited by Steve Lolait (8th Nov 2011 15:30:37)