This research also highlights the fact that the child’s individuality—its unique genetic makeup—exists from the moment of conception.At conception, the new person’s genetic instructions come together for the first time—in a single cell called the zygote.But it is not until day 6 that IDO production kicks in.5 Why day 6?Well day 6 is a preparation for day 7, when the new embryo first attaches itself to its mother’s womb so that it can draw nutrients from its mother’s bloodstream. This is exactly the time when the mother’s killer T cells would normally begin to attack and reject it—if not for the amazing protection already provided by IDO production on the previous day.
Tumour hijacks fetal enzyme
The lead author of the 1998 paper on IDO referred to in the main text, David Munn, has continued his research on IDO’s role elsewhere in the body and found an exactly parallel process to the pregnancy case at work in the body’s tolerance of tumours.Just as the embryo produces IDO to protect itself from the mother’s immune system, so rogue tumour cells also use the same trick to stop a person’s immune system from attacking and rejecting the tumour. These insights are helping to find new ways of treating tumours and reducing the rejection rate of surgical transplants.