Fc 优化的抗 CTLA-4 抗体增加肿瘤相关的高内皮微静脉并使难治性肿瘤对 PD-1 阻断敏感

The lack of T cells in tumors is a major hurdle to successful immune checkpoint therapy (ICT).

Therefore, therapeutic strategies promoting T cell recruitment into tumors are warranted to improve the treatment efficacy.

Here, we report that Fc-optimized anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) antibodies are potent remodelers of tumor vasculature that increase tumor-associated high endothelial venules (TA-HEVs), specialized blood vessels supporting lymphocyte entry into tumors.

Mechanistically, this effect is dependent on the Fc domain of anti-CTLA-4 antibodies and CD4 + T cells and involves interferon gamma (IFNγ). Unexpectedly, we find that the human anti-CTLA-4 antibody ipilimumab fails to increase TA-HEVs in a humanized mouse model.

However, increasing its Fc effector function rescues the modulation of TA-HEVs, promotes CD4 + and CD8 + T cell infiltration into tumors, and sensitizes recalcitrant tumors to programmed cell death protein 1 (PD-1) blockade.

Our findings suggest that Fc-optimized anti-CTLA-4 antibodies could be used to reprogram tumor vasculature in poorly immunogenic cold tumors and improve the efficacy of ICT.