Cell surface polysaccharides of Bifidobacterium bifidum induce the generation of Foxp3(+) regulatory T cells
Dysregulation of intestinal microflora is linked to inflammatory disorders associated with compromised immunosuppressive functions of Foxp3(+) T regulatory (Treg) cells. Although mucosa-associated commensal microbiota has been implicated in Treg generation, molecular identities of the "effector" components controlling this process remain largely unknown. Here, we have defined Bifidobacterium bifidum as a potent inducer of Foxp3(+) Treg cells with diverse T cell receptor specificity to dietary antigens, commensal bacteria, and B. bifidum itself. Cell surface beta-glucan/galactan (CSGG) polysaccharides of B. bifidum were identified as key components responsible for Treg induction. CSGG efficiently recapitulated the activity of whole bacteria and acted via regulatory dendritic cells through a partially Toll-like receptor 2-mediated mechanism. Treg cells induced by B. bifidum or purified CSGG display stable and robust suppressive capacity toward experimental colitis. By identifying CSGG as a functional component of Treg-inducing bacteria, our studies highlight the immunomodulatory potential of CSGG and CSGG-producing microbes.
|ISBN||2470-9468 (Electronic) 2470-9468 (Linking)|
|Authors||Verma, R.; Lee, C.; Jeun, E. J.; Yi, J.; Kim, K. S.; Ghosh, A.; Byun, S.; Lee, C. G.; Kang, H. J.; Kim, G. C.; Jun, C. D.; Jan, G.; Suh, C. H.; Jung, J. Y.; Sprent, J.; Rudra, D.; De Castro, C.; Molinaro, A.; Surh, C. D.; Im, S. H.|
|Responsible Garvan Author|
|Publisher Name||Science Immunology|
|URL link to publisher's version||https://www.ncbi.nlm.nih.gov/pubmed/30341145|