<i>Bifidobacterium infantis</i> associates with T cell immunity in human infants and is sufficient to enhance antigen-specific T cells in mice
Donald Nyangahu, Anna‐Ursula Happel, Jerome Wendoh, Agano Kiravu, Yuli Wang, Colin Feng, Courtney R. Plumlee, Sara Cohen, Bryan P. Brown, Danijel Djukovic, Tariq Ganief, Melanie Gasper, Daniel Raftery, Jonathan M. Blackburn, Nancy L. Allbritton, Clive M. Gray, Jisun Paik, Kevin B. Urdahl, Heather B. Jaspan
Abstract
Bacille Calmette-Guerin (BCG) vaccine can elicit good T H 1 responses in neonates. We hypothesized that the pioneer gut microbiota affects vaccine T cell responses. Infants who are HIV exposed but uninfected (iHEU) display an altered immunity to vaccination. BCG-specific immune responses were analyzed at 7 weeks of age in iHEU, and responses were categorized as high or low. Bifidobacterium longum subsp. infantis was enriched in the stools of high responders, while Bacteroides thetaiotaomicron was enriched in low responders at time of BCG vaccination. Neonatal germ-free or SPF mice orally gavaged with live B. infantis exhibited significantly higher BCG-specific T cells compared with pups gavaged with B. thetaiotaomicron. B. infantis and B. thetaiotaomicron differentially affected stool metabolome and colonic transcriptome. Human colonic epithelial cells stimulated with B. infantis induced a unique gene expression profile versus B. thetaiotaomicron . We thus identified a causal role of B. infantis in early-life antigen-specific immunity.