Expression of T-bet, Eomesodermin and GATA-3 in porcine αβ T cells

• Decreasing levels of GATA-3 in thymocytes along the DN-DP-SP maturation pathway.
• Uniform CD8α+CD27− phenotype of T-bet+ CD4+ T cells.
• Uniform perforin+CD27dim/− phenotype of T-bet+ CD8β+ T cells.
• Low frequencies of Eomes+ CD4+ and CD8β+ T cells, partially with naïve phenotype.

The transcription factors GATA-3, T-bet and Eomesodermin play important roles in T-cell development, differentiation and memory formation. However, their expression has not been studied in great detail in porcine T cells. We report on protein expression at the single cell-level of these transcription factors in thymocytes and mature αβ T cells. GATA-3 expression was found in γδ− thymocytes, with decreasing expression from the CD4−CD8α− stage towards single-positive stages. Extra-thymic CD4+ T cells but not CD8β+ T cells expressed low levels of GATA-3, which decreased with age. CD4+ and CD8β+ T-bet+ cells mainly displayed a CD8α+CD27− and perforin+CD27dim/− phenotype, respectively and had the capacity for IFN-γ production; indicative of an effector/effector memory phenotype. Eomesodermin+ αβ T cells had mixed phenotypes in regard to CD8α, CD27 and perforin expression. In conclusion, our data so far support the hitherto reported roles for GATA-3 in T-cell development and T-bet for Th1 effector-differentiation, but question the role of Eomesodermin for memory formation of porcine T-cells.