The intestinal epithelium is an enriched source for 78 T cells and approximately general 30-50 % of intraepithelial lymphocytes (ffiLs) are yS T cells which can be separated into CDSand CD4-8' or double negative (DN) fractions. Since we have characterized the profiles of type 1 and type 2 cytokine synthesized by different subsets of lELs, we have now compared profiles of cytokine expression between CDSand DN 78 T cells isolated from murine EELs by using qualitative and quantitative RT-PCR. When RNA was isolated from both fractions of freshly prepared yS T cells, strong message for IFN-y(type 1) was noted. Further, on weak message for type 2 cytokines such as IL-4, IL-5, IL-6 and EL-10 were detected. The quantitative RT-PCR analysis showed that DN y8 T cells expressed 20 to 30 fold higher IL-5 and IL-6 specific messages when compared with those of CD8+, yS T cells, while mRNA levels for other cytokines (IFN-y, IL-4 and EL-10) were essentially comparable between CDSand DN y8 T cells. When these two subsets of yS IEL were stimulated with anti-y5 TCR antibody, the level of messages for EL-2, EL-5 and EL-6 were increased in both CD8+ and DN y8 T cells when compared with the unstimulated group. These findings suggested that CDSand DN y8 EELs are competent to express mRNA for type 1 and type 2 cytokines and certain cytokines, e.s., IL-2, EL-5 and EL-6 were upregulated upon stimulation signals provided via the TCR.