Endocytosis of commensal antigens by intestinal epithelial cells regulates mucosal T cell homeostasis.
Mark S LadinskyLeandro P AraujoXiao ZhangJohn VeltriMarta Galán-DíezSalima SoualhiCarolyn LeeKoichiro IrieElisha Y PinkerSeiko NarushimaSheila BandyopadhyayManabu NagayamaWael ElhenawyBrian K CoombesRonaldo P FerrarisKenya HondaIliyan D IlievNan GaoPamela J BjorkmanIvaylo I IvanovPublished in: Science (New York, N.Y.) (2019)
Commensal bacteria influence host physiology, without invading host tissues. We show that proteins from segmented filamentous bacteria (SFB) are transferred into intestinal epithelial cells (IECs) through adhesion-directed endocytosis that is distinct from the clathrin-dependent endocytosis of invasive pathogens. This process transfers microbial cell wall-associated proteins, including an antigen that stimulates mucosal T helper 17 (TH17) cell differentiation, into the cytosol of IECs in a cell division control protein 42 homolog (CDC42)-dependent manner. Removal of CDC42 activity in vivo led to disruption of endocytosis induced by SFB and decreased epithelial antigen acquisition, with consequent loss of mucosal TH17 cells. Our findings demonstrate direct communication between a resident gut microbe and the host and show that under physiological conditions, IECs acquire antigens from commensal bacteria for generation of T cell responses to the resident microbiota.
Keyphrases
- cell wall
- dendritic cells
- ulcerative colitis
- patient safety
- induced apoptosis
- cell cycle
- quality improvement
- single cell
- gene expression
- microbial community
- cell cycle arrest
- cell therapy
- regulatory t cells
- gram negative
- stem cells
- staphylococcus aureus
- cell death
- cell proliferation
- protein protein
- immune response
- oxidative stress
- multidrug resistant
- escherichia coli
- cystic fibrosis