Characterization of a murine thymic CD4~ T cell subset-TCRαβ~ 3G11~- 6C10~- CD4~ CD8~- thymocytes

The presence of a relatively mature CD4 ~ CD8~- (SP) T cell subset in mouse thymus has been demonstrated. Composing of 10% of total CD4SP thymocytes, this subset is defined by the absence of 3G11 and 6C10 expression with a phenotype of CD69~( /-), HSA~(med/lo) and heterogeneous for Qa-2 expression. The proliferation capability of TCRαβ~ 3G11~- 6C10~- CD4~ CD8~- thymocytes was high while using Con A stimulus. And Con A stimulation could result in secretion of IL-4, IL-10, IL-6 and a little amount of IFNγ. IL-2 was barely detectable. This is distinct from typical Th0 type cytokines. The cells of this subset were NK1.1 negative, but strongly expressed GATA-3 mRNA. The results suggest that the CD4~ subset of 3G11~- 6C10~- NK1.1~- phenotype possesses immunocompetent cells with functions characteristic of Th2-like cytokines, which may indicate the cells at transitional status from Th0 to Th2, with a propensity to Th2.