Abstract
The critical role of the mother’s immune system in promoting a healthy pregnancy
Leigh Guerin
PhD candidate, Discipline of Obstetrics and Gynaecology,
University of Adelaide
The genetic difference between a mother and its fetus presents a problem to the mother’s immune system. Typically the immune system will simply recognise and attack any foreign tissues or organism that it recognises as “non-self”. Indeed this should be the situation during pregnancy, resulting in fetal loss. The reason that this doesn’t occur in a normal pregnancy is that the immune system has develop several methods to stop itself from attacking the fetus. This process is referred to as immune tolerance. One of the critical cells in promoting immune tolerance is a white blood cell called a regulatory T cell. These regulatory T cells use several methods to control the immune system and promote immune tolerance. One of these is the use of a signalling molecule called interleukin-10. However despite this critical role of interleukin-10, in animals that have no interleukin-10 the mothers are still able to have healthy pregnancies.
We aimed to look at the regulatory T cells in mice that were deficient in interleukin-10 to see if the absence of this molecule affected their abundance or function. We found that during pregnancy mice who didn’t have interleukin-10 had a hugely increased number of regulatory T cells and that these cells appeared not to be compromised in their ability to promote immune tolerance. We think that this large increase in regulatory T cell numbers may act to compensate for the loss of interleukin-10 so that the pregnancy isn’t compromised. This demonstrates how during pregnancy there are many pathways that the body can use to maintain this critically important tolerance of the fetus.
