CD161 expression defines new human γδ T cell subsets.

Area of Science:

• Immunology
• Cell Biology

Background:

• Gamma delta (γδ) T cells are crucial for immune defense and maintaining homeostasis.
• Their heterogeneity, precise functions, and roles in health and disease require further elucidation.

Purpose of the Study:

• To identify novel γδ T cell subsets, particularly in middle-to-old age individuals.
• To investigate the role of CD161 expression in defining γδ T cell phenotypes and their potential link to disease.

Main Methods:

• Multi-parametric flow cytometry was employed to analyze γδ T cell populations.
• Dimensionality reduction, unsupervised clustering, and self-organizing maps (SOM) were utilized for subset identification.
• Analysis included comparison between healthy elderly individuals and patients with bronchiectasis.

Main Results:

• Novel γδ T cell subsets were identified, primarily distinguished by CD161 expression levels.
• Vδ1+ γδ T cells predominantly showed a terminally differentiated phenotype, while Vδ1- cells displayed an early memory phenotype.
• Elevated Vδ1+ terminally differentiated effector memory cells were observed in bronchiectasis patients compared to healthy controls.

Conclusions:

• CD161 expression is a key marker for defining γδ T cell heterogeneity and their differentiation states.
• The Vδ1+ terminally differentiated effector memory γδ T cell subset may be implicated in chronic inflammatory conditions such as bronchiectasis.