Innate immune cells in the adipose tissue

Area of Science:

• Immunology
• Metabolism
• Adipose Tissue Biology

Background:

• Immune cells reside in adipose tissue (AT) and influence its function.
• Lean AT is characterized by type 2 immunity (eosinophils, M2 macrophages, innate lymphoid cells 2), promoting metabolic homeostasis.
• Obesity leads to a shift towards pro-inflammatory immune cells (e.g., M1 macrophages) in AT.

Purpose of the Study:

• To discuss the crosstalk between immune cells and adipocytes in AT.
• To highlight the role of innate immune cells in AT inflammation during obesity.
• To examine the impact on metabolic homeostasis and systemic metabolism.

Main Methods:

• Review of existing literature on immune cell populations in AT.
• Analysis of the functional roles of different immune cell types in lean vs. obese states.
• Discussion of the molecular and cellular interactions between immune cells and adipocytes.

Main Results:

• Type 2 immune cells maintain metabolic homeostasis in lean AT.
• Pro-inflammatory immune cells dominate in obese AT, contributing to inflammation.
• Obesity-associated AT inflammation is linked to insulin resistance, type 2 diabetes, and cardiovascular disease.

Conclusions:

• Immune cell-adipocyte crosstalk in AT is a key regulator of AT function and systemic metabolism.
• Innate immune cells play a critical role in AT inflammation and metabolic dysregulation in obesity.
• Understanding this crosstalk is vital for developing strategies against obesity-related metabolic complications.