Lenalidomide enhances the function of dendritic cells generated from patients with multiple myeloma.

Lenalidomide (LEN) has been used as an immunomodulatory drug with direct and indirect anti-tumor effects. In this study, we evaluated the effect of LEN on the differentiation, maturation, and function of dendritic cells (DCs) in patients with multiple myeloma in vitro. Various doses of LEN were added after the monocytes had differentiated into immature DCs and were activated into mature DCs. LEN (5 μg/mL) was the optimal concentration to promote differentiation and maturation of DCs. Immature DCs treated with LEN exhibited enhanced endocytic capacity. Mature DCs treated with LEN produced higher levels of interleukin-12p70, possessed stronger allogeneic T-cell stimulation capacity, reduced the number of suppressor cells, and generated antigen-specific cytotoxic T lymphocytes more potently compared with control DCs. These results suggest that LEN enhanced the function of DCs generated from patients with multiple myeloma by stimulating the capacity of allogeneic T cells, inhibiting the generation of immunosuppressive cells, inducing naïve T cells toward Th1 polarization, and generating potent myeloma-specific cytotoxic T lymphocytes.