IL-25 inhibits atherosclerosis development in apolipoprotein E deficient mice

Area of Science:

• Immunology
• Cardiovascular Disease Research
• Innate Immunity

Background:

• Interleukin-25 (IL-25) is known to initiate type 2 immunity and protect against autoimmune diseases.
• Innate lymphoid type 2 cells (ILC2s) have been identified as a key target population for IL-25.
• Atherosclerosis is a chronic inflammatory disease affecting arteries.

Purpose of the Study:

• To investigate the influence of IL-25 on the development of atherosclerosis in a mouse model.
• To explore the mechanisms by which IL-25 might affect atherosclerosis, focusing on innate immune responses.

Main Methods:

• Administration of IL-25 to atherosclerosis-prone apolipoprotein E-deficient mice.
• Analysis of T cell populations, ILC2 expansion, and cytokine levels (IL-5).
• Evaluation of natural antibody production (anti-phosphorylcholine IgM) and B1a cell populations.
• Assessment of atherosclerosis progression in the aorta.

Main Results:

• IL-25 treatment led to significant expansion of splenic ILC2s in mice.
• Increased levels of IL-5 and anti-phosphorylcholine IgM antibodies were observed.
• IL-25 administration reduced atherosclerosis in the aorta during both initiation and progression phases.
• IL-5 was found to be crucial for natural antibody production downstream of ILC2 expansion.

Conclusions:

• IL-25 plays a protective role in atherosclerosis through innate immune mechanisms.
• Key mediators include ILC2 expansion, IL-5 secretion, B1a cell proliferation, and natural anti-PC IgM generation.
• The protective effect appears to be mediated by innate responses, not adaptive Th2 responses.