Fig. 1.

Mechanism of action of PD-1/PD-L1 antibody combined with TNFR2 antibody. IL-6 and TNF-α synergistically induce the binding of signal transducer and activator of transcription 3 (STAT3) and TNFR2 promoter in tumor cells to promote the expression of TNFR2. Then, TNF-α-TNFR2 activates the expression of PD-L1 via NF-κB to induce T cell depletion, promote tumor cell growth and enhance the function of immunosuppressive cells. The combination of TNFR2 antibody and PD-1/PD-L1 antibody can inhibit the proliferation of Treg and tumor-associated macrophage (TAM), induce the apoptosis of tumor cells and the expression of PD-L1, and thus enhance the tumor-killing effect of T cells