IMMUNOLOGY2025™ Conference Recordings-Mapping uncharted landscapes of host-microbiota connectivity

Video Transcription

Video Summary

Joan Goverman opened the AAI BD Biosciences Investigator Award session by introducing Dr. Noah Palm, an early-career immunologist whose work is transforming understanding of how the microbiota and immune system communicate. BD Biosciences representative Bob Balderas reflected on the history of the award, its long support of young investigators, and BD’s continued commitment to the scientific community.<br /><br />Dr. Palm then delivered an exploratory lecture framed around the idea that scientific discovery, like Polynesian navigation, requires venturing into uncertainty. He described the microbiome field as a “new world” revealed by omics technologies, but also a field limited by a major problem: vast microbial data exist with little functional annotation. His lab has responded by building technologies that use the host as a lens to identify causal microbes and mechanisms.<br /><br />The main focus of the talk was a newly developed yeast-display-based platform called BaseHIT, which maps direct interactions between cultured microbes and the human exoproteome. This approach identified thousands of potential host-microbe interactions and validated many known ones, showing the method is both sensitive and biologically meaningful. The screen revealed patterns linked to bacterial niche, phylogeny, and strain-specific differences.<br /><br />Dr. Palm highlighted three examples: Bacteroides strains affecting IgA responses, Fusobacterium interacting with the “don’t eat me” receptor SIRPα, and, most extensively, Ruminococcus navus. This commensal, strongly associated with Crohn’s disease, was found to bind multiple immune-related host proteins, including antibodies, trefoil factors, and CD7. His lab identified bacterial proteins responsible for CD7 binding, suggesting that some commensals may actively manipulate host immunity rather than merely evade it.<br /><br />He concluded that these findings open new questions about immunogenic commensals, microbial “virulence factors,” and the evolutionary logic of host-microbe interactions.

Keywords

microbiome

host-microbe interactions

immunology

BaseHIT

yeast display

Ruminococcus navus

Crohn's disease

SIRPα

IgA responses

CD7