Ex vivo assays show human gamma-delta T cells specific for common allergens are Th1-polarized in allergic donors

• Published in: Cell reports methods Vol. 2; no. 12; p. 100350
• Main Authors: Yu, Esther Dawen, Wang, Eric, Garrigan, Emily, Sutherland, Aaron, Khalil, Natalie, Kearns, Kendall, Pham, John, Schulten, Veronique, Peters, Bjoern, Frazier, April, Sette, Alessandro, da Silva Antunes, Ricardo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19.12.2022; Elsevier
• Subjects: allergy; cytokine production; functional assay; gamma-delta; T cells; Th1; gamma-delta; γδ; cytokine production; allergy; functional assay; T cells; Th1
• ISSN: 2667-2375; 2667-2375
• DOI: 10.1016/j.crmeth.2022.100350

Gamma-delta (γδ) T cells contribute to the pathology of many immune-related diseases; however, no ex vivo assays to study their activities are currently available. Here, we established a methodology to characterize human allergen-reactive γδ T cells in peripheral blood using an activation-induced marker assay targeting upregulated 4-1BB and CD69 expression. Broad and reproducible ex vivo allergen-reactive γδ T cell responses were detected in donors sensitized to mouse, cockroach, house dust mite, and timothy grass, but the response did not differ from that in non-allergic participants. The reactivity to 4 different allergen extracts was readily detected in 54.2%–100% of allergic subjects in a donor- and allergen-specific pattern and was abrogated by T cell receptor (TCR) blocking. Analysis of CD40L upregulation and intracellular cytokine staining revealed a T helper type 1 (Th1)-polarized response against mouse and cockroach extract stimulation. These results support the existence of allergen-reactive γδ T cells and their potential use in rebalancing dysregulated Th2 responses in allergic diseases. [Display omitted] •Ex vivo assays using peripheral blood can detect human γδ T cell responses•Upregulated 4-1BB and CD69 expression tag allergen-reactive human γδ T cells•γδ T cell responses are donor and allergen specific and abrogated by TCR blocking•Mouse and cockroach allergen-specific γδ T cell responses are Th1-polarized Current methodologies for studying gamma-delta (γδ) T cells are limited to clonal expansion and long-term in vitro cultures. As a result, insufficient insights are offered to fully understand the role of γδ T cells in human diseases. Here, we report the development of a methodology that reliably identifies antigen-reactive γδ T cells in human peripheral blood mononuclear cells (PBMCs) both quantitatively and qualitatively. A characterization of antigen-reactive γδ T cells was performed for several allergen extracts in allergic and non-allergic individuals. However, no major differences were observed, likely due to the complex composition of allergen extracts, which requires further studies on individual antigen components. Yu et al. characterize human gamma-delta (γδ) T cells in peripheral blood using ex vivo assays. They find that human γδ T cells specific for common environmental allergens are Th1-polarized in allergic donors. γδ T cells could be of immunotherapeutic use to rebalance dysregulated Th2 responses in allergic diseases.