Figure 3.

Schematic of functional interactions of immune cells and with malignant plasma cells. The anti-myeloma activity of T cells, natural killer cells (NK), natural killer T cells (NKT), and γδ T cells against MM plasma cells is inhibited by malignant plasma cells via the activation of T regulatory cells (Tregs) and stimulation of myeloid-derived suppressor cells (MDSCs). Moreover, dendritic cell activity is also inhibited by Tregs and MDSCs. This makes the microenvironment immunologically permissive towards myelomatous proliferation and induces MM plasma cell escape from immune surveillance.