Antigenic experience dictates functional role of glycogen synthase kinase-3 in human CD4+ T cell responses

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• T cell receptor (TCR) and CD28 costimulation inactivate glycogen synthase kinase-3 (GSK3).
• GSK3 is implicated in interleukin-2 (IL-2) production and T cell proliferation.
• The role of GSK3 in naive versus memory CD4(+) T cell responses is not fully understood.

Purpose of the Study:

• To investigate the role of GSK3 inactivation in human naive and memory CD4(+) T cell proliferation.
• To explore the specific functions of GSK3beta in memory CD4(+) T cell responses.

Main Methods:

• Stimulation of human naive and memory CD4(+) T cells via TCR and CD28.
• Assessment of GSK3 phosphorylation status (inactivation).
• Analysis of T cell proliferation and IL-10 production.

Main Results:

• CD28 costimulation increased GSK3 inactivation in both naive and memory CD4(+) T cells.
• Memory CD4(+) T cells showed less reliance on GSK3 inactivation for proliferation compared to naive cells.
• GSK3beta was found to regulate IL-10 recall responses in memory CD4(+) T cells.
• Inactivated GSK3beta in memory cells led to IL-10-dependent suppression of bystander T cell proliferation.

Conclusions:

• There is a divergence in GSK3 inactivation dependency between naive and memory CD4(+) T cell proliferation.
• GSK3beta plays a novel role in regulating IL-10 recall responses and bystander suppression by memory CD4(+) T cells.
• These findings highlight a functional dichotomy of GSK3 in distinct human CD4(+) T cell populations.