AHG0090 is a Genetically Tractable Bacterium and Produces a Secreted Peptidic Bioactive That Suppresses Nuclear Factor Kappa B Activation in Human Gut Epithelial Cells

is an early coloniser of the human infant gut and contributes to the development of intestinal immunity. To better understand the functional capacity of , we constructed a broad host range RP4 mobilizable vector, pEHR513112, that confers chloramphenicol resistance and used a metaparental mating approach to isolate AHG0090 from a fecal sample collected from a healthy human infant. We demonstrated that AHG0090 is genetically tractable and could be manipulated using traditional molecular microbiology approaches. AHG0090 was comparable to the gold-standard anti-inflammatory bacterium A2-165 in its ability to suppress cytokine-mediated nuclear factor kappa B (NF-κB) activation in human gut-derived LS174T goblet cell like and Caco-2 enterocyte-like cell lines. AHG0090 and A2-165 produced secreted low molecular weight NF-κB suppressive peptidic bioactives. Both bioactives were sensitive to heat and proteinase K treatments although the AHG0090 bioactive was more resilient to both forms of treatment. As expected, AHG0090 suppressed IL-1β-induced NF-κB-p65 subunit nuclear translocation and expression of the NF-κB regulated genes IL-6, IL-8 and CXCL-10. Finally, we determined that AHG0090 is distantly related to other commensal strains and likely encodes niche factors that support effective colonization of the infant gut.