Two functionally distinct subsets of IL-17 producing γδ T cells.

Area of Science:

• Immunology
• Cellular Biology
• T-cell research

Background:

• Gamma delta (γδ) T cells are vital immune cells, producing Interleukin-17 (IL-17), a key cytokine for pathogen resistance.
• In mice, IL-17-producing γδ T cells (γδT-17) consist of two subsets defined by T-cell receptor (TCR) expression: Vγ6Vδ1+ and Vγ4+.
• Murine γδT-17 cells develop a predisposition for IL-17 production during thymic maturation.

Purpose of the Study:

• To review the similarities and differences between the two distinct types of murine γδT-17 cells.
• To discuss the potential implications arising from the distinct characteristics of these γδT-17 cell subsets.
• To explore the evidence for analogous IL-17-producing γδ T cell subsets in humans and their developmental differences.

Main Methods:

• Review of existing literature on γδ T cell subsets and IL-17 production.
• Comparative analysis of TCR Vγ and Vδ chain expression in murine γδT-17 cells.
• Examination of evidence for distinct γδ T cell subsets in human immunity.

Main Results:

• Two distinct subsets of γδT-17 cells exist in mice, characterized by invariant Vγ6Vδ1+ or Vγ4+ TCRs.
• Murine γδT-17 cells are imprinted for IL-17 production during thymic development.
• Evidence suggests two similar subsets in humans, but they likely acquire IL-17 bias in the periphery, not the thymus.

Conclusions:

• The distinct developmental pathways of murine γδT-17 cell subsets may have significant implications for immune responses.
• Understanding these differences is crucial for comprehending γδ T cell heterogeneity and function.
• Human IL-17-producing γδ T cells may differ fundamentally in their developmental programming compared to mice.