Type 3 innate lymphoid cells maintain intestinal epithelial stem cells after tissue damage

Area of Science:

• Immunology
• Gastroenterology
• Stem Cell Biology

Background:

• The intestinal epithelial barrier is vital for preventing inflammation and requires continuous stem cell proliferation.
• Anticancer therapies can damage the gut lining due to high cell turnover, causing side effects.
• Mechanisms of mucosal protection and healing after intestinal damage are not fully understood.

Purpose of the Study:

• To investigate the role of Type 3 innate lymphoid cells (ILC3s) in intestinal epithelial repair after damage.
• To determine if ILC3s are necessary for maintaining intestinal stem cells following chemotherapy-induced injury.

Main Methods:

• Utilized ILC3-deficient Lgr5 reporter mice to study stem cell maintenance.
• Induced small intestinal tissue damage using the chemotherapeutic agent methotrexate.
• Analyzed epithelial activation, proliferation, and tissue pathology in the presence and absence of ILC3s and IL-22.

Main Results:

• ILC3s are required for epithelial activation and proliferation after methotrexate-induced intestinal damage.
• Absence of ILC3s leads to increased pathology and severe damage to intestinal crypts.
• Maintenance of intestinal stem cells is severely impaired without ILC3s or IL-22.

Conclusions:

• Type 3 innate lymphoid cells play a critical role in protecting the intestinal epithelium.
• ILC3s preserve intestinal stem cells, thereby limiting tissue damage and promoting mucosal healing.
• This study reveals a novel protective function of ILC3s in the context of chemotherapy-induced gut injury.