Leptin modulates autophagy in human CD4+CD25- conventional T cells

Area of Science:

• Immunology
• Cell Biology
• Endocrinology

Background:

• Leptin is an adipocytokine involved in regulating energy balance and immune function.
• Autophagy is a cellular degradation process crucial for immune cell homeostasis.
• Conventional T cells (Tconv) play a central role in adaptive immunity.

Purpose of the Study:

• To investigate the direct effect of leptin on autophagy in human CD4(+)CD25(-) Tconv cells.
• To elucidate the molecular mechanisms underlying leptin-mediated modulation of autophagy.
• To understand the interplay between leptin, autophagy, and T cell activation.

Main Methods:

• In vitro treatment of Tconv cells with recombinant human leptin.
• Assessment of autophagy using western blotting and flow cytometry.
• Analysis of the mammalian-target of rapamycin (mTOR) pathway.
• Co-immunoprecipitation assays to study Bcl-2 and Beclin-1 interactions.

Main Results:

• Leptin inhibited autophagy in Tconv cells during T cell receptor (TCR) stimulation in a dose- and time-dependent manner.
• Leptin-induced autophagy inhibition was mediated by the activation of the mTOR pathway.
• Leptin treatment led to Bcl-2 up-regulation and its interaction with Beclin-1, negatively impacting autophagy.

Conclusions:

• Leptin directly modulates autophagy in human Tconv cells.
• Leptin controls both autophagy and proliferation in Tconv cells during TCR engagement.
• Autophagy and proliferation appear to occur alternatively, suggesting a balance during immune activation.