Mice study may provide new insight on human pregnancies

October 01, 2015

"These T cells are functioning in an antigen-specific manner," Kahn notes. "In other words, their function requires the presence of the specific fetal antigens."

In their studies of these animals, the scientists also found that pregnancy tolerance "develops actively as a consequence of pregnancy," says Kahn. "The mice are not born with it." Indeed, virgin mice showed no signs of these pregnancy-specific Treg cells. Conversely, the cells were found in larger numbers in those individual mice that had given birth to more male babies, with the level of Treg cells increasing with the number of male births.

The next step, Kahn adds, is to look at Tregs and their role in pregnancy tolerance in humans-a line of research that may lead to new insights into such pregnancy-related conditions as preeclampsia, in which high blood pressure and other symptoms develop in the second half of pregnancy. Preeclampsia is a major cause of maternal mortality around the world.

"There's a lot to be learned," he says. "Pregnancy is often ignored in research because it's usually successful, and because-from an immunologic standpoint-it has such complexity. Until now, it's been difficult to grab a handle on how the immunology of pregnancy really works."

The work described in the PNAS article, "Pregnancy induces a fetal antigen-specific maternal T regulatory cell response that contributes to tolerance," was supported in part by a research grant from the Skirball Foundation. Kahn is supported by the National Institutes of Health's Building Interdisciplinary Research Careers in Women's Health Center at UCLA.

Source: California Institute of Technology