Gut Immune Maturation Depends on Colonization With a Host-Specific Microbiota

Cell. 2012 Jun 22;149(7):1578-93. doi: 10.1016/j.cell.2012.04.037.

Abstract

Gut microbial induction of host immune maturation exemplifies host-microbe mutualism. We colonized germ-free (GF) mice with mouse microbiota (MMb) or human microbiota (HMb) to determine whether small intestinal immune maturation depends on a coevolved host-specific microbiota. Gut bacterial numbers and phylum abundance were similar in MMb and HMb mice, but bacterial species differed, especially the Firmicutes. HMb mouse intestines had low levels of CD4(+) and CD8(+) T cells, few proliferating T cells, few dendritic cells, and low antimicrobial peptide expression--all characteristics of GF mice. Rat microbiota also failed to fully expand intestinal T cell numbers in mice. Colonizing GF or HMb mice with mouse-segmented filamentous bacteria (SFB) partially restored T cell numbers, suggesting that SFB and other MMb organisms are required for full immune maturation in mice. Importantly, MMb conferred better protection against Salmonella infection than HMb. A host-specific microbiota appears to be critical for a healthy immune system.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / metabolism
  • Cell Proliferation
  • Female
  • Germ-Free Life
  • Humans
  • Immunity, Innate*
  • Intestines / immunology*
  • Intestines / microbiology*
  • Male
  • Metagenome*
  • Mice
  • Rats
  • Rats, Sprague-Dawley
  • Salmonella Infections / immunology
  • Species Specificity
  • Specific Pathogen-Free Organisms
  • Symbiosis
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology