Low-dose cyclophosphamide depletes circulating naïve and activated regulatory T cells in malignant pleural mesothelioma patients synergistically treated with dendritic cell-based immunotherapy.

: Regulatory T cells (Treg) play a pivotal role in the immunosuppressive tumor micro-environment in cancer, including mesothelioma. Recently, the combination of autologous tumor lysate-pulsed dendritic cells (DC) and metronomic cyclophosphamide (mCTX) was reported as a feasible and well-tolerated treatment in malignant pleural mesothelioma patients and further as a method to reduce circulating Tregs. : The aim of this study was to establish the immunological effects of mCTX alone and in combination with DC-based immunotherapy on circulating Treg and other T cell subsets in mesothelioma patients.

Interleukin-21: an interleukin-2 dependent player in rejection processes.

Background: Interleukin (IL)-21 is the most recently described cytokine that signals via the common cytokine receptor (gammac), is produced by activated CD4+ T-cells, and regulates expansion and effector function of CD8+ T-cells.

Materials: To explore the actions of IL-21 with other gammac-dependent cytokines in alloreactivity, mRNA expression of IL-21, IL-21R alpha-chain, and IL-2 proliferation and cytotoxicity was measured after stimulation in mixed lymphocyte reactions. Additionally, IL-21 and IL-21R alpha-chain expression was studied in biopsies of heart transplant patients.