Administration of anti-CD25 mAb leads to impaired α-galactosylceramide-mediated induction of IFN-γ production in a murine model.

CD4(+)CD25(+)Foxp3(+) T regulatory cells (Tregs) and CD1d-restricted invariant natural killer T (iNKT) cells are two cell types that are known to regulate immune reactions. Depletion or inactivation of Tregs using specific anti-CD25 antibodies in combination with immunostimulation is an attractive modality especially in anti-tumour immunotherapy. However, CD25 is not expressed exclusively on Tregs but also on subpopulations of activated lymphocytes.

Cyclophosphamide-induced myeloid-derived suppressor cell population is immunosuppressive but not identical to myeloid-derived suppressor cells induced by growing TC-1 tumors.

Myeloid-derived suppressor cells (MDSC) play an important role in tumor escape from antitumor immunity. MDSC accumulate in the lymphoid organs and blood during tumor growth and their mobilization was also reported after cyclophosphamide (CY) administration. In this communication, spleen MDSC accumulating after CY therapy (CY-MDSC) were compared with those expanded in mice bearing human papilloma viruses 16-associated TC-1 carcinoma (TU-MDSC).