Deficiency of programmed cell death 4 affects the balance of T cell subsets in hyperlipidemic mice

Area of Science:

• Immunology
• Molecular Biology
• Cardiovascular Research

Background:

• Programmed cell death 4 (Pdcd4) initially linked to apoptosis, now recognized as a tumor suppressor inhibiting transcription and translation.
• Emerging evidence suggests Pdcd4's role in inflammatory diseases and immune responses.
• Previous studies indicated Pdcd4 deficiency attenuates atherosclerotic plaque formation, possibly via macrophage IL-10 expression and lipoautophagy, reducing foam cells.

Purpose of the Study:

• To investigate the effect of Pdcd4 on T cell subsets in hyperlipidemic mice.
• To elucidate the mechanisms by which Pdcd4 influences T cell populations in a hyperlipidemic microenvironment.

Main Methods:

• In vitro and in vivo experiments were conducted using hyperlipidemic mouse models.
• Flow cytometry was used to analyze T cell subsets (CD8+ T cells, regulatory T cells).
• Expression levels of co-stimulatory (CD28, CD137) and co-inhibitory (CTLA-4) molecules were assessed.

Main Results:

• Pdcd4 deficiency led to a decreased percentage of CD8+ T cells.
• Pdcd4 deficiency resulted in an increased percentage of regulatory T cells (Tregs).
• These changes were associated with reduced expression of CD28 and CD137, and enhanced expression of CTLA-4.

Conclusions:

• Endogenous Pdcd4 promotes T cell-mediated immune responses by regulating co-stimulatory molecule expression.
• Pdcd4's role in modulating T cell subsets may contribute to the progression of advanced atherosclerotic plaques.
• This study provides novel insights into Pdcd4's function in distinct T cell subsets within a hyperlipidemic context.