Regulating colonic dendritic cells by commensal glycosylated large surface layer protein A to sustain gut homeostasis against pathogenic inflammation

Mucosal Immunol. 2020 Jan;13(1):34-46. doi: 10.1038/s41385-019-0210-0. Epub 2019 Oct 16.

Abstract

Microbial interaction with the host through sensing receptors, including SIGNR1, sustains intestinal homeostasis against pathogenic inflammation. The newly discovered commensal Propionibacterium strain, P. UF1, regulates the intestinal immunity against pathogen challenge. However, the molecular events driving intestinal phagocytic cell response, including colonic dendritic cells (DCs), by this bacterium are still elusive. Here, we demonstrate that the glycosylation of bacterial large surface layer protein A (LspA) by protein O-mannosyltransferase 1 (Pmt1) regulates the interaction with SIGNR1, resulting in the control of DC transcriptomic and metabolomic machineries. Programmed DCs promote protective T cell response to intestinal Listeria infection and resist chemically induced colitis in mice. Thus, our findings may highlight a novel molecular mechanism by which commensal surface glycosylation interacting with SIGNR1 directs the intestinal homeostasis to potentially protect the host against proinflammatory signals inducing colonic tissue damage.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism*
  • Cell Differentiation
  • Cells, Cultured
  • Colitis / chemically induced
  • Colitis / immunology*
  • Colon / immunology*
  • Dendritic Cells / immunology*
  • Humans
  • Inflammatory Bowel Diseases / immunology*
  • Lectins, C-Type / genetics
  • Lectins, C-Type / metabolism*
  • Listeria / physiology*
  • Listeriosis / immunology*
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Propionibacterium / metabolism*
  • Protein Binding
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • Symbiosis
  • T-Lymphocytes / immunology*

Substances

  • Bacterial Proteins
  • Cell Adhesion Molecules
  • DC-specific ICAM-3 grabbing nonintegrin
  • Lectins, C-Type
  • Receptors, Cell Surface