Fluorescent Staphylococcus epidermidis (red) on the skin (stratum corneum in green, epidermis in blue). UCSF, TIFFANY SCHARSCHIMDTThe skin is home to millions of commensal bacteria and immune cells. Yet how the skin microbiome is established—in particular, why the immune system does not attack these bacteria—has been little studied. Now, a team led by researchers at the University of California, San Francisco (UCSF), has shown that, to establish tolerance by the immune system, colonization of the skin by commensal bacteria occurs during the first few days after birth in mice. The team’s findings were published today (November 17) in Immunity.
“This is an elegant and well-executed study showing a regulatory T cell–mediated establishment of commensal-specific tolerance,” said Keisuke “Chris” Nagao of the National Cancer Institute in Bethesda, Maryland, who was not involved in the work.
“There is a fair amount known about how the innate immune system responds to the skin’s microbiome, but very little about the adaptive immune response to microbes in the skin,” said study coauthor Michael Rosenblum, a dermatologist and immunologist at UCSF.
One reason is the challenge of genetically manipulating bacterial species native to the skin. In the current study, Rosenblum, along with Tiffany Scharschmidt, an assistant professor of dermatology at UCSF, and their colleagues were able to overcome this hurdle, creating one of the first genetically engineered commensal skin microbes. ...
