Semen does not behave as antigen to woman

Why semen doesnt act like foreign body to women?

some1 asked this to me overOrkutComm

Fetus [the product of semen ]that iz xpressing the antigen of father ..is in the placenta. Placenta is a immunopreviledged site which is coated wid sialic acid or like [can"t recapitulate sorry ] which is not foreign to mother. Inside this coat is the fetus ..wid its paternal / own antigen hidden. Now blood from mom does not direct come to fetus. Only plasma come ..not any blood cell. So the fetal body do not evoke immunity inside placenta



But acc to matzinger hypoth , as fetus or sperm is not doing any harm to mom , so no antibody elicits. But i dont agree to disHypothesis. My frnd also asks not to write it.So plz overlook dis atpresent

Now why sperm is not directly killed inside uterus? everyday men eat millions of foreign proteins,every day hundreds of foreign antigens are entering respiratory pathAndNoseBut there is no immune reactivity. If hen\duck egg protein is injected intra muscular or iv ...there ud b immunity. But upon eating , when the protein encounter oral and esophagus mucosa [ before digestion in stomach, though stomach digestion does not reduce or stop antigenicity of that egg protein ] .... then there shud b strong antibody productn. ButIt DoesNot Occur. Becos mucosal imunity is different. Here sumtime a Th2 response [not Th 1 ] result in suppressor B .... which causes suppression of imunity. Same is there in uterine endometrium. Besides spermatozoa hav sialic acid coat probably which hides the antigen

Then life of sperm is 2days. it mayNotAFFORD enough time for the increase of antibody level to a titre .... that too with factorsListed above .. to kill all million of sperms
Yes if u test blood of a lady [having sexual intercourse ] .. ab for sperm UD SURE be FOUND

And other point is continued low dose exposure 2 a foreign protein ie semen[without adjuvant ] causes peripheral imune tolerance in the corresponding lady partner .

And still sumtime imune activity occur against sperm. SeminalAntign acts as immunogen and that is the cause of many eclampsia.Several studies have investigated the strongly decreased incidence of pre-eclampsia in women who had received blood transfusions from their partner, those with long, preceding histories of sex without barrier contraceptives, and in women who had been regularly performing oral sex, with one study concluding that "induction of allogeneic tolerance to the paternal HLA molecules of the fetus may be crucial. Data collected strongly suggests that exposure, and especially oral exposure to soluble HLA from semen can lead to transplantation tolerance."

# Bonney EA (December 2007). "Preeclampsia: a view through the danger model". Journal of Reproductive Immunology 76 (1-2): 68–74. doi:10.1016/j.jri.2007.03.006. PMID 17482268.

# Koelman CA, Coumans AB, Nijman HW, Doxiadis II, Dekker GA, Claas FH (March 2000). "Correlation between oral sex and a low incidence of preeclampsia: a role for soluble HLA in seminal fluid?". Journal of Reproductive Immunology 46 (2): 155–66. doi:10.1016/S0165-0378(99)00062-5. PMID 10706945

# Johansson M, Bromfield JJ, Jasper MJ, Robertson SA (June 2004). "Semen activates the female immune response during early pregnancy in mice". Immunology 112 (2): 290–300. doi:10.1111/j.1365-2567.2004.01876.x. PMID 15147572