Innate Lymphoid Cells Promote Anatomical Containment of Lymphoid-Resident Commensal Bacteria

TLDR

A barrier protects commensal bacteria in the gut and lymphoid tissue, but disease‑induced breaches cause chronic inflammation. In mice, ILCs maintain bacterial containment via IL‑22; removing ILCs or blocking IL‑22 causes loss of containment and systemic inflammation. Sonnenberg et al.

Abstract

Protecting Against a Barrier Breach In order to coexist peacefully, a “firewall” exists that keeps the commensal bacteria that reside in our intestines and associated lymphoid tissue contained. Several diseases and infections, however, lead to a breach in this barrier, which leads to chronic inflammation and pathology. Sonnenberg et al. (p. 1321 ) found that in mice, innate lymphoid cells (ILCs) are critically important for the anatomical containment of commensal bacteria in an interleukin-22 (IL-22)–dependent manner. ILC depletion or blockade of IL-22 led to loss of bacterial containment and systemic inflammation.