Biology:Polysaccharide A
Polysaccharide A (PSA) is a polysaccharide produced by the Gram-negative bacterium Bacteroides fragilis.[1] B.fragilis produces eight identified distinct capsular polysaccharides, identified by the letters "A" through "H".[2]
PSA interacts with Toll-like receptor 2 (TLR2) on dendritic cells.[3] PSA colonization of B. fragilis in the gut mucosa induces regulatory T cells and suppresses pro-inflammatory T helper 17 cells.[2] PSA has been shown to protect animals from experimental diseases like colitis, asthma, or pulmonary inflammation.[2] Nonetheless, PSA can be pro-inflammatory as well as anti-inflammatory.[4]
PSA has been studied extensively in the spleen and gastrointestinal tract, but PSA uses regulatory T cells to reduce inflammation in the central nervous system.[3]
References
- ↑ "A potential species of next-generation probiotics? The dark and light sides of Bacteroides fragilis in health". Food Research International 126. 2019. doi:10.1016/j.foodres.2019.108590. PMID 31732047.
- ↑ 2.0 2.1 2.2 "Exploring the Gut-Brain Axis for the Control of CNS Inflammatory Demyelination: Immunomodulation by Bacteroides fragilis' Polysaccharide A". Frontiers in Immunology 12. 2021. doi:10.3389/fimmu.2021.662807. PMID 34025663.
- ↑ 3.0 3.1 "Gut microbiota, metabolites and host immunity". Nature Reviews Immunology 16 (6): 341-352. 2016. doi:10.1038/nri.2016.42. PMID 27231050.
- ↑ "Characterization of Polysaccharide A Response Reveals Interferon Responsive Gene Signature and Immunomodulatory Marker Expression". Frontiers in Immunology 11. 2020. doi:10.3389/fimmu.2020.556813. PMID 33193325.
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