WIKIMEDIA, ERNEST FFrom the sterile world of the womb, at birth babies are thrust into an environment full of bacteria, viruses, and parasites. They are very vulnerable to these infections for their first months of life—a trait that has long been blamed on their immature immune systems.
But Shokrollah Elahi from the Cincinnati Children’s Hospital Medical Center has shown that, at least in mice, this susceptibility is the work of special cells that actively suppress immune responses in newborns. This raises their risk of diseases, but it also creates a window during which helpful bacteria can colonize their guts. The results are published today (November 6) in Nature.
“This more intricate regulation of immune responses makes more sense than immaturity,” said Sing Sing Way, who led the study, “because it allows a protective response to be mounted if needed.” This may explain why newborn immune responses, though generally weak, also vary wildly between different babies and across different studies.
If the same suppressive cells are at work in humans, Way suggested that ...
