FoxP3, a lineage-defining transcription factor, defines mammalian Tregs together with antibodies against CD25, GITR, and CTLA-4. No valid chicken anti-FoxP3 or surface CTLA-4 antibodies are available to date. Given current experimental tools, the study proposes CD4+CD25+GITR+ as a practical panel for phenotypic characterization and sorting of viable chicken Tregs.
ABSTRACT
Regulatory T cells (Tregs) are fundamental to immune homeostasis, maintaining peripheral tolerance and preventing pathological autoimmunity across vertebrate species. The recent publication, “Beyond FoxP3: Identification of a Chicken Regulatory T Cell Signature,” in the European Journal of Immunology by Naumann et al., addresses a critical gap in comparative immunology by providing a comprehensive phenotypic and transcriptional characterization of chicken Treg cells. This commentary will situate the study within the historical context of Treg research, underscore the specific challenges in avian Treg characterization, and highlight the work’s transformative implications for both basic immunology and applied poultry science.