The skin is home to millions of microbial residents that coexist peacefully with their host playing a key role in maintaining health without causing harm. Interestingly these microbes can also trigger complex immune responses even without the presence of infection or injury.

For her research on how the immune system responds to these beneficial skin microbes Djenet Bousbaine a postdoctoral fellow at Stanford University has been awarded the 2025 NOSTER & Science Microbiome Prize. This prestigious award recognizes early-career scientists conducting innovative microbiome research with potential for therapeutic impact.

Our immune system is constantly interacting with the harmless bacteria on our skin said Bousbaine. Our findings suggest this interaction can be harnessed to develop effective topical vaccines.

Caroline Ash senior editor at Science added It’s exciting to see such a diverse and impressive group of entries for the 2025 prize showcasing remarkable expertise across the field.

Previous studies have shown that immune responses to the microbiome are both common and highly specific comparable to those triggered by harmful pathogens.

However unlike typical immune reactions to pathogens these responses to commensal microbes occur without inflammation and even across intact barriers like the skin.

In her prize-winning essay published in the July 3 issue of Science Djenet Bousbaine explores how the immune system interacts with Staphylococcus epidermidis a beneficial skin microbe. Her research revealed that this microbe stimulates not only wound-healing T cells but also strong, antigen-specific B cell responses.

Bousbaine’s team identified a surface protein on the bacterium known as accumulation-associated protein (Aap) as the main antigen recognized by B cells during colonization.

Building on this discovery the researchers tested whether this natural immune interaction could be adapted for vaccination purposes.

By inserting a harmless fragment of tetanus toxin into the Aap protein they engineered S. epidermidis to display a foreign antigen. When applied to the skin this modified microbe triggered a powerful systemic antibody response in mice effectively protecting them from a lethal dose of tetanus toxin.

Bousbaine noted that the findings open the door to using similarly engineered skin microbes as topical self-administered vaccines in the future.

Now in its sixth year this prize reflects our global dedication to advancingh  microbiome research for the betterment of all said Kohey Kitao CEO of NOSTER Inc. We’re proud to support emerging scientists whose work could pave the way for innovative microbiome-based therapies contributing to safe and sustainable healthcare solutions worldwide.

Source: https://www.aaas.org/news/immune-responses-skin-microbiome-could-pave-way-novel-vaccination-responses