An Ocular Commensal Protects against Corneal Infection by Driving an Interleukin-17 Response from Mucosal γδ T Cells
Our bodies are home to trillions of microbes that help maintain health, from the bacteria in our gut to those in our mouths, noses, and skin. But what about the eye? While the eye’s surface is a mucosal site—like the intestine or nasal passages—scientists have long debated whether it harbors its own community of resident microbes.
In this collaborative study, we discovered that the ocular surface does, in fact, host a living microbiomewith important immune functions. Among these microbes, we identified Corynebacterium mastitidis, a bacterial ally that triggers a protective immune response. This tiny guardian activates specialized γδ T cells, prompting them to release interleukin-17, a key immune molecule. The result? A surge of neutrophils (immune cells) and the release of natural antimicrobials into the tears—creating a frontline defense against harmful invaders like Candida albicans and Pseudomonas aeruginosa.
This discovery challenges the long-held belief that the eye is a sterile environment. Instead, we show that a resident ocular microbiome exists and plays a crucial role in immune defense, shaping how we think about eye health and protection against infections.
I have greatly appreciated the opportunity to contribute to this collaborative work with Prof. R. Caspi and Prof. A. St. Leger, whose exceptional research and collaborative spirit have been truly inspiring.
Published in Immunity 2017. Follow the link below for the full-text.