Preterm births and pregnancy complications could one day be avoided using a vaccine that turns off the mother's immune response. The mechanism could also be used in treating diseases where the immune system of the body turns hostile like Type 1 diabetes.

Medical Daily had earlier reported a study that had described how a mother's body knows that it should not kill the fetus growing inside her. It turns out that certain genes coding for a protein, chemokine, are shut down during pregnancy which otherwise would have accumulated T cells and killed the fetus.

The memory of an immune suppression during the first pregnancy is maintained in the body and when the mother gets pregnant again, the body is ready to protect the baby instead of attacking it which is why subsequent deliveries are less complicated.

Researchers say that this mechanism can be applied to help the body maintain a good immune response and not start attacking the body like it does in autoimmune diseases.

"We show definitively immune suppressive regulatory CD4 cells can form immunological memory. These memory features shown in pregnancy illustrate why complications become reduced in subsequent compared with primary pregnancy, but can also be broadly applied to new ways to better control the stringent balance between immune stimulation and suppression for preventing autoimmune diseases,"  said Sing Sing Way, MD  from Cincinnati Children's and the study's senior author.

Researchers say that in the future it might be possible to design vaccines that target T cells that retain the memory of a specific antibody and increase their number in the body so that the body knows when to suppress an attack.

"With the polio vaccine, for example, vaccination is designed to induce long-lasting immune-activating cells that eradicate the virus with later infection. A vaccine that targets the expansion and retention of immune suppressive cells would allow selective silencing of undesired responses and prevent them from attacking the body," said Way.

The study was published in Nature.