NRP1 instructs IL-17-producing ILC3s to drive colitis progression

Area of Science:

• Immunology
• Gastroenterology
• Cell Biology

Background:

• Group 3 innate lymphoid cells (ILC3s) are crucial for maintaining intestinal homeostasis and regulating mucosal inflammation.
• The specific molecular mechanisms controlling ILC3 function, particularly in the context of inflammatory bowel disease (IBD), remain incompletely understood.

Purpose of the Study:

• To identify novel regulators of intestinal ILC3 activity.
• To investigate the role of neuropilin-1 (NRP1) in ILC3 function and its potential as a therapeutic target for IBD.

Main Methods:

• Analysis of intestinal mucosal biopsies from IBD patients and healthy controls.
• Genetic deficiency models to assess the impact of NRP1 on ILC3 frequency and IL-17A production.
• In vivo studies using dextran sodium sulfate (DSS)-induced colitis model.
• Pharmacological inhibition of NRP1 using EG00229.

Main Results:

• Neuropilin-1 (NRP1) was found to be significantly upregulated in intestinal tissues of IBD patients.
• Genetic deficiency of NRP1 led to reduced ILC3 numbers and impaired IL-17A production in a cell-intrinsic, NF-κB-dependent manner.
• Reduced IL-17A production by ILC3s altered gut microbiota composition and ameliorated DSS-induced colitis.
• Pharmacological inhibition of NRP1 with EG00229 effectively reduced colitis severity.

Conclusions:

• Neuropilin-1 (NRP1) acts as a key positive regulator of IL-17-producing ILC3s in the intestine.
• NRP1 plays a critical role in the pathogenesis of intestinal inflammation.
• Targeting NRP1 presents a promising therapeutic strategy for managing inflammatory bowel disease (IBD).