fig2

Figure 2. Hypoxic tumor-secreted exosomes promote an immunosuppressive TME. Hypoxic tumor-secreted exosomes promote an immunosuppressive TME by interfering with several intracellular pathways and modulating immune accessory cells, including cytotoxic T cells, T-regulatory cells (Tregs), myeloid-derived suppressor cells (MDSCs), natural killer cells (NK), and tumor-associated macrophages (TAMs). (1) Inhibition of T cell proliferation; (2) stimulation of Treg differentiation; (3) induction of MDSCs; (4) impairment of NK cells; and (5) stimulation of M2 polarization of TAMs.