Background: It has been proposed that a reduced immunological competence and a dysregulation in the T1/T2 balance may be implicated in the development of cancer. In order to study the immunological situation in vivo, we compared the mRNA expression of the T1 cytokine IFN-gamma and the T2 cytokine IL-10 in freshly isolated, not in vitro stimulated, peripheral blood lymphocytes from patients with localized prostate carcinomas (PCa) and benign prostate hyperplasia (BPH).
Materials and methods: Peripheral blood mononuclear cells (PBMC) were isolated by gradient centrifugation. CD4(+)- and CD8(+)-lymphocytes were selected with magnetic beads against these determinants. In these lymphocyte preparations, mRNA expression of IL-10 and IFN-gamma was determined by using a semiquantitative RT-PCR, standardized to the beta-actin expression.
Results: In the PBMC from 35 patients with localized PCa a significantly lower expression of IFN-gamma and IL-10 was found, compared to 28 patients with BPH. Cytokine expression also was lower in the isolated CD4(+)- and CD8(+)-lymphocytes of the carcinoma patients. However, the difference was statistically significant only for IL-10.
Conclusion: Our data reflect a reduced basal cytokine expression in peripheral lymphocytes of patients with localized PCa compared to BPH. Since the T2 response was more strongly reduced than T1, there seems to be a decreased immune activation, but a relative T1 dominant cytokine pattern in the cancer patients.