Human Th1 cells that express CD300a are polyfunctional and after stimulation up-regulate the T-box transcription...

Area of Science:

• Immunology
• Cell Biology

Background:

• Naïve CD4 T cells express low CD300a, while effector/memory cells show variable expression.
• CD300a expression may define a distinct subset within effector/memory CD4 T cells.

Purpose of the Study:

• To investigate the functional characteristics of CD300a-expressing CD4 T cells.
• To determine the role of CD300a in defining Th1 cell subsets and their associated transcription factors.

Main Methods:

• Ex vivo analysis of human CD4 T cells.
• Flow cytometry to assess CD300a expression.
• Measurement of cytokine production (IFN-gamma, TNF-alpha, IL-2) and transcription factor expression (Eomes, T-bet).

Main Results:

• CD4 T cells producing IFN-gamma are enriched in the CD300a(+) subset.
• Polyfunctional CD4 T cells (producing IFN-gamma, TNF-alpha, IL-2) are predominantly CD300a(+).
• Stimulated CD300a(+) CD4 T cells exhibit increased Eomes expression, while T-bet is similarly upregulated in both CD300a(+) and CD300a(-) cells.

Conclusions:

• CD300a(+) human Th1 cells are often polyfunctional and up-regulate Eomes after stimulation.
• TGF-beta1 inhibits CD300a expression and down-regulates Eomes and IFN-gamma, suggesting a role in dictating Th1 subset development.