One of the key questions for those studying pregnancy is how is the foetus (which expresses genes from both the mother and father) tolerated by the maternal immune system. If the foetus is considered a transplant, the paradoxical nature of pregnancy can be best understood. Namely, whereby a transplant such as a heart or kidney would be ordinarily rejected by the host (in this case the mother), in this case, the transplant (which is partly derived from the father), is accepted by the host. This is therefore indicative of a specific acceptance of paternal genes by the mother during pregnancy to ensure foetal survival. Consequently, an abundance of research has been carried out in order to try and elucidate what mechanisms could be acting during pregnancy so that the foetus is not rejected.

This question has shaped the last 4 years of my life. After graduating from the University of Glasgow with a degree in Immunology, I decided to pursue a PhD in the field of Reproductive Immunology at the Royal Veterinary College. I demonstrated that foetally-derived cells possessed the capacity to adapt the maternal immune system, aiding in the prevention of foetal rejection in the horse. These adaptations prevented immune cells from becoming ‘over-activated’, increasing the risk of fetal attack. Furthermore, I also was able to characterise a novel cell subset in the horse, namely T regulatory cells (Robbin MG. et al 2011). T regulatory cells have been characterised in a number of other species, including humans, dogs, cats and sheep, so identification of the equine counterparts was important both in its own right and for contribution to the comparative sciences.

Despite species-specific differences that exist during pregnancy, the mechanisms that help with fetal acceptance are likely to be similar across species. The results yielded from my PhD are therefore likely to be applicable to a range of species, including humans - utilising a horse model therefore has wide reaching implications. Ultrasound imaging was also imperative so that pregnancy could be established.

When undertaking a PhD, one of the risks is becoming what could be described as ‘blinkered’. Your life becomes consumed with your studies, and it was not unheard of for a middle of the night wakeup call where my brain had a breakthrough – interrupting my beauty sleep! I have no doubt in my mind that the discoveries in the field of Reproductive Immunology are set to significantly grow, and that the paradoxical nature of pregnancy will be revealed, with the help of both the human and veterinary species.