This study aims to determine the extent to which semen is important in initiating the maternal immune response to the fetus and placenta during pregnancy. We postulate that exposure to paternal proteins in sperm and other factors present in the semen may have a cumulative, beneficial effect in 'educating' the female immune system to respond in the correct way to the embryo when pregnancy occurs. To investigate this, the behaviour and movements of white blood cells responding to semen will be stu ....This study aims to determine the extent to which semen is important in initiating the maternal immune response to the fetus and placenta during pregnancy. We postulate that exposure to paternal proteins in sperm and other factors present in the semen may have a cumulative, beneficial effect in 'educating' the female immune system to respond in the correct way to the embryo when pregnancy occurs. To investigate this, the behaviour and movements of white blood cells responding to semen will be studied during the period after mating, in which the uterus prepares for and accommodates to pregnancy. In particular, the study will focus on the roles of a specific chemical messenger substance in semen, called transforming growth factor (TGF)-beta, which triggers the molecular changes leading to maternal immune tolerance. A deeper understanding of these events will have an important impact in human and veterinary medicine where implantation failure is a major cause of reproductive loss and inadequate placental growth poses a threat to the health of the conceptus both in utero and into adult life.Read moreRead less
Immunobiology Of Early Pregnancy - A Model Of Virus-induced Abortion
Funder
National Health and Medical Research Council
Funding Amount
$454,500.00
Summary
The lack of 'self' molecule expression on the trophoblast cells of the placenta which interface directly with the mother's circulation, as well as the local suppression of the mother's immune response at this interface, may be important factors in the successful implantation of the embryo. This immunological 'silence' allows the embryo, whose paternal genetic contribution makes it immunologically foreign to the mother, to escape the rejection reaction normally associated with foreign graft trans ....The lack of 'self' molecule expression on the trophoblast cells of the placenta which interface directly with the mother's circulation, as well as the local suppression of the mother's immune response at this interface, may be important factors in the successful implantation of the embryo. This immunological 'silence' allows the embryo, whose paternal genetic contribution makes it immunologically foreign to the mother, to escape the rejection reaction normally associated with foreign graft transplantation. Infection with flaviviruses increases the concentrations of cell surface self and adhesion molecules in vertebrate cells, including the trophoblast cells of the placenta. As a result, these molecules can then be recognised by the maternal immune system and the embryo targeted for destruction. We hypothesise that the induction of these molecules by this and other viruses may break the immunological silence of the early embryo and reverse the local suppression of the maternal immune response. This would result in maternal immune rejection of the embryo and abortion. This initial sensitisation of the mother by the virus might be one of the reasons that some women suffer recurrent abortions. We will use a novel viral mouse model where we implant virus-infected embryos into receptive animals to enable us to dissect out the unusual requirements for induction of maternal anti-viral immunity during pregnancy. This model was developed in our laboratory to directly test our hypotheses. It does not cause systemic illness in the mother which itself can lead to non-specific abortion. This model therefore can for the first time elucidate the specific mechanisms associated with the delicate balance between eradicating virus and maintaining pregnancy. Results from this project will inform rational design of treatment of recurrent abortions in the community.Read moreRead less