Cholesterol lowering modulates T cell function in vivo and in vitro

Area of Science:

• Immunology
• Cardiovascular Research
• Lipid Metabolism

Background:

• The lipid environment influences atherosclerosis by exacerbating inflammation.
• The precise impact of lipids on T cell-mediated immunity remains incompletely understood.

Purpose of the Study:

• To investigate how lipid lowering affects T cell-mediated immune function.
• To explore the mechanisms underlying lipid modulation of T cell responses.

Main Methods:

• Assessed T cell proliferation in response to T cell receptor (TCR) ligation using varying fetal bovine serum (FBS) concentrations.
• Analyzed changes in lipid rafts, cellular cholesterol, and cytokine secretion (IL-10, IL-12).
• Evaluated immune biomarkers in apolipoprotein E-deficient (apoE-/-) mice on an atherogenic diet, with a subset switched to a normal diet.

Main Results:

• T cells showed increased proliferation in standard FBS compared to delipidated FBS, linked to lipid rafts and cholesterol content.
• Lipid lowering in apoE-/- mice reduced circulating cholesterol, plaque size, and plaque inflammation.
• Dietary changes correlated with decreased intracellular IL-10 and IL-12 expression in CD4+ and CD8+ T cells.

Conclusions:

• Lipid lowering demonstrably reduces T cell proliferation and function.
• These findings support the role of lipid modulation in altering T cell activity both in vitro and in vivo.