Quantitative analysis of cytokine mRNA expression in peripheral blood mononuclear cells following treatment with interleukin-2

After activation with interleukin-2 (IL-2), peripheral blood mononuclear cells (PBMC) have been reported to induce the expression of mRNA coding various cytokines, including interleukin(IL)-1α, -1β and tumor necrosis factor α (TNFα). We examined the cytokine mRNA expression of PBMC following treatment with IL-2 in vitro and in vivo by a quantitative method using the reverse transcription/polymerase chain reaction (RTPCR). After stimulating PBMC with IL-2 in vitro, peak levels of IL-1α mRNA were reached between 3 h and 12 h, and thereafter declined. The IL-1β expression increased, with levels peaking at 1-6 h and, had decreased by 96 h. The expression of TNFα was elevated both 1-3 h and 2448 h after stimulation. The peak levels of IL- 1α and -1β mRNA and the early elevation of TNFα mRNA mainly accounted for the cytokine mRNA expression in adherent cells; however, the late induction of TNFα mRNA was observed in nonadherent cells. In patients with advanced carcinoma, the IL-1α and -1β mRNA expression were elevated after IL-2 treatment for 5 consecutive days, while the expression of TNFα mRNA also increased. These results indicate that the quantitative RT-PCR method appears to be useful for analyzing the cytokine mRNA expression of PBMC after treatment with IL-2.