Positive immunoregulation of thalidomide on human peripheral blood mononuclear cell cultures

This study was purposed to investigate the effects of thalidomide on proliferation of peripheral blood mononuclear cells (PBMNCs), levels of lymphocyte subsets, secretion of cytokines and its killing activity, and to elucidate the immunoregulation mechanisms in treatment of multiple myeloma with thalidomide. The method of MTT was used to detect the effects of thalidomide on the proliferations and the cytotoxic activity of PBMNC; the flow cytometer was used to analyze the lymphocyte subsets; the ELISA was used to measure the concentrations of cytokines in culture supernatants. The results showed that thalidomide enhanced the proliferations of the CD8+ T, NK cells in PHA-stimulated PBMNC from healthy volunteers, increased the secretion of IL-6 significantly, and decreased the secretion of IFN-gamma, and the secretions of IL-2 and IL-10 were not affected. Compared with control group, at the same ratio of effectors to targets the thalidomide (5 microg/ml) could enhance the cytotoxic activity of PBMNC (P < 0.01), the cytotoxic activity was maximal when the ratio of effectors to targets was 40:1. It is concluded that thalidomide preferentially enhances the proliferations of CD8+ T, NK cells in PHA-stimulated PBMNC from healthy volunteers, and enhances the cytotoxic activity of PBMNC by increasing the secretion of IL-6 significantly, in short, thalidomide can exert anti-myeloma effects by increasing cellular immune function.