Regulatory T Cells Control Effector T Cell Inflammation in Human Prediabetes

Area of Science:

• Immunology
• Metabolic Disease
• Cellular Biology

Background:

• Prediabetes involves chronic inflammation, but its specific T cell profiles are poorly understood, unlike type 2 diabetes.
• Current mouse models inadequately replicate human prediabetes inflammation.
• CD4+ T cell inflammatory profiles offer a unique perspective on prediabetes.

Purpose of the Study:

• To define the unique inflammatory state of prediabetes mediated by CD4+ T cells.
• To investigate the role of regulatory T cells (Treg) and effector T cells (Teff) in prediabetes inflammation.
• To identify molecular mechanisms, specifically CD36, by which Treg influence Teff metabolism and cytokine production in prediabetes.

Main Methods:

• Analysis of CD4+ T cell inflammatory profiles in human prediabetes.
• Investigating the regulatory function of Treg on Teff mitochondrial function and cytokine production (Th17, Th1).
• Gene expression analysis to identify key molecules like CD36 involved in Treg and Teff metabolism.
• Pharmacological blockade of CD36 in Treg to assess its impact on Teff cytokine production.

Main Results:

• Prediabetes is characterized by a distinct inflammatory profile driven by CD4+ T cells.
• Treg differentially regulate Teff cytokine production in prediabetes (Th17) versus type 2 diabetes (Th1).
• The fatty acid transporter CD36 is highly expressed in Treg, but not Teff, in prediabetes.
• Blocking CD36 in Treg reduced Th17 cytokine production by Teff, a key feature of prediabetes inflammation.

Conclusions:

• Treg control CD4+ T cell cytokine profiles via metabolic regulation, influenced by the host's metabolic status.
• CD36 expressed by Treg is crucial for promoting Th17 cytokine production by Teff in prediabetes.
• Targeting Treg CD36 presents a potential therapeutic strategy for modulating prediabetes inflammation.