Type 2 immunity in intestinal homeostasis and inflammatory bowel disease

Biochem Soc Trans. 2021 Nov 1;49(5):2371-2380. doi: 10.1042/BST20210535.


Type 2 immune responses commonly emerge during allergic reactions or infections with helminth parasites. Most of the cytokines associated with type 2 immune responses are IL-4, IL-5, and IL13, which are mainly produced by T helper 2 cells (TH2), eosinophils, basophils, mast cells, and group 2 innate lymphoid cells (ILC2s). Over the course of evolution, humans have developed type 2 immune responses to fight infections and to protect tissues from the potential collateral damage caused by inflammation. For example, worm parasites induce potent type 2 immune responses, which are needed to simultaneously clear the pathogen and to promote tissue repair following injury. Due to the strong type 2 immune responses induced by helminths, which can promote tissue repair in the damaged epithelium, their use has been suggested as a possible treatment for inflammatory bowel disease (IBD); however, the role of type 2 immune responses in the initiation and progression of IBD is not fully understood. In this review, we discuss the molecular and cellular mechanisms that regulate type 2 immune responses during intestinal homeostasis, and we briefly discuss the scarce evidence linking type 2 immune responses with the aetiology of IBD.

Keywords: ILC2; TH2; inflammatory bowel disease; mucosal immunology; type 2 immunity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Cytokines / immunology
  • Homeostasis / immunology*
  • Humans
  • Inflammatory Bowel Diseases / immunology*
  • Intestinal Mucosa / immunology
  • Intestines / immunology
  • Intestines / metabolism*


  • Cytokines