Phosphocholine and our entrance to this world

Nov 12, 2007 09:06 GMT  ·  By

A fetus is like a strange organism living inside the woman's womb. The fetus develops the placenta, a special organ for sucking food and oxygen from the mother. But the placenta, like the fetus, has a different DNA from that of the mother, and the body generally attacks parasites and foreign bodies using all the tools of the immune system. How does the placenta manage to counteract this?

Simply acting as a parasite worm, reveals a new research at University of Reading, a discovery that could help fight against miscarriages and pre-eclampsia (womb convulsions that can cause spontaneous aborts). A method of lowering the immune reaction could also ease symptoms of chronic inflammations, like arthritis.

Scientists only knew that the placenta synthesized a small protein, called neurokinin B (NKB), in much higher amounts in cases of pre-eclampsia. NKB is already produced in detectable quantities at just 9 weeks of pregnancy, pointing towards risk cases.

The Reading team was seeking for a diagnostic kit based on NKB, but they realized that the placental type of the protein had a different reaction from the form tested in the laboratory. The placental synthesis of NKB worked differently. The cause? The placental NKD was found to be bound to phosphocholine, a chemical employed by the parasitic nematode worms (like roundworms) to impede the attack by our immune systems.

"When we saw this, our immediate instinct was to look at other proteins in the placenta. So far, from what we have seen, it appears a large number of them possess this protein surface molecule which cloaks them from the host immune system. Devising a mechanism by which you could make cells invisible to the immune system could lead to cures for a number of diseases and conditions.", said lead researcher Professor Phil Lowry.

Phosphocholine bound proteins could fight autoimmune diseases like rheumatoid arthritis. "The mother does not react to the placenta in the way you would expect her to, and we have been aware for a long time that the placenta appears to coat itself in some way. This finding potentially has a lot of implications for how the immune system can be modulated in various diseases, from cancer to arthritis, but there is still a lot of work to be done.", said Professor James Walker, an expert in obstetrics and gynecology at St James Hospital, Leeds.