将新型抗 CTLA-4 纳米抗体与 IgG1 Fc 区融合可增强其诱导 CD8(+) T 细胞介导的抗实体瘤免疫应答的能力

Our previously described a nanobody precisely targeting CTLA-4 and demonstrated that it can promote the antitumor response of adoptive T cells. Here we examined whether fusing it to the IgG1 Fc region would induce stronger, longer-lasting T-cell immune responses after exposure to the dendritic-tumor cell fusions.

The fusion of nanobody to Fc region was overexpressed in E. coli . Next, the proliferation, activation and cytotoxicity of the CD8 + T cells stimulated by the fusion protein and dendritic-tumor cell fusions was assessed in vitro, and the antitumor activity was evaluated in nude mice bearing xenografts of each type of solid tumor.

Proliferation, activation and cytotoxicity of CD8 + T cells in vitro were significantly greater in the presence of the fusion protein than those in other groups. Consistently, different types of xenografts growth were significantly slower and animal survival significantly longer when the injected CD8 + T cells had been activated in vitro in the presence of the fusion protein.

Fusing our anti-CTLA-4 nanobody to the IgG1 Fc region potentiates its ability to induce strong, persistent CD8 + T cell responses against solid tumors in mice. This fusion strategy has the potential to realize clinical transformation and application to clinical treatment.