Semiquantitative analysis of Th1 and Th2 cytokine expression in CD3(+), CD4(+), and CD8(+) renal-cell-carcinoma-infiltrating lymphocytes

The mRNA expression of Th1 and Th2 cytokines was compared in freshly isolat ed CD3(+) tumor-infiltrating lymphocytes (CD3(+) TIL) and in autologous CD3 (+) peripheral blood lymphocytes (CD3(+) PBL) obtained simultaneously from 20 patients with renal cell carcinomas (RCC). In addition cytokine expressi on was compared in CD4(+) TIL and CD8(+) TIL from another group of 20 patie nts with RCC. TIL were isolated from mechanically disaggregated tumor mater ial and PBL from peripheral blood by gradient centrifugation and subsequent selection with anti-CD3, anti-CD4 or anti-CD8 magnetic beads. In these pur e lymphocyte preparations the constitutive expression of interleukin-l (IL- 1), IL-2, IL-10, interferon gamma (IFN gamma), and tumor necrosis factor al pha (TNF alpha) was determined by using a polymerase-chain-reaction-assiste d mRNA amplification assay. In the CD3(+) TIL, levels of mRNA for IFN gamma , IL-10, IL-1 and TNF alpha were significantly higher than in the autologou s CD3(+) PBL whereas IL-2 expression was rather low and did not differ in t he two populations. Comparison of cytokine mRNA expression in CD4(+) TIL an d simultaneously obtained CD8(+) TIL revealed a significantly higher expres sion of IFN gamma in CD8(+) cells. These data reflect an in vivo activation of RCC-infiltrating lymphocytes at the mRNA level with respect to the Th1 as well as the Th2 immune response. Th1 activation seems to be most evident in the CD8(+) TIL.