Obesity aggravates contact hypersensitivity reaction in mice

Area of Science:

• Immunology
• Dermatology
• Metabolic Diseases

Background:

• Obesity is linked to chronic inflammation and skin diseases.
• The specific impact of obesity on contact hypersensitivity (CHS) remains unclear.

Purpose of the Study:

• To investigate how obesity affects T helper 1 (Th1)-mediated CHS.
• To explore the role of gut microbiota and Interleukin-17A (IL-17A) in obesity-associated CHS.

Main Methods:

• Assessed immune cell activity and cytokine profiles in vivo and in vitro.
• Utilized quantitative polymerase chain reaction (qPCR) and fecal microbiota transplantation (FMT).
• Investigated the impact of high-fat diet (HFD)-induced gut microbiota dysbiosis on CHS.

Main Results:

• Obese mice exhibited exacerbated CHS, linked to a pro-inflammatory gut microbiota.
• A pro-inflammatory environment was observed in adipose tissue, with increased inflammatory CD4+ T cells and dendritic cells.
• Mice deficient in IL-17A were protected from CHS aggravation, highlighting IL-17A's role.

Conclusions:

• Obesity promotes the development of potent CHS-effector cells but does not affect already activated cells.
• IL-17A is essential for the increased severity of CHS observed in obesity.
• Findings offer insights into obesity-related skin disorders and potential therapeutic targets.