以纳米抗体多聚体为新组装单元的生物大分子自组装及其功能化

纳米抗体是一类新型抗体，它以结构稳定、分子量小、易于表达纯化、免疫原性低为典型特征，近年来迅速发展为颇具潜力的治疗性蛋白质。从大分子自组装的角度看，上述优势使得纳米抗体作为新组装基元同样具有广阔发展空间。遗憾的是，这方面研究目前文献中还没有关注。因此本项目提出，通过构筑卷曲螺旋与荧光蛋白纳米抗体的融合蛋白质，得到该纳米抗体多聚体，并利用抗体与荧光蛋白之间的特异性作用，结合聚合物所参与的微相分离，构筑具有全新结构和组成的蛋白质-聚合物组装体。通过调整卷曲螺旋的种类和融合蛋白的构筑，我们可获得基于纳米抗体多聚体与聚合物的超分子聚合物、囊泡等组装体和宏观凝胶。初步研究结果表明，所得凝胶具有招募巨噬细胞的能力，即可特异性引起免疫细胞的趋化。我们将深入研究上述趋化作用发生的分子机制，并将该趋化作用应用于促进效应性免疫细胞的肿瘤局部浸润，最终实现与免疫检查点抑制剂抗体抗肿瘤效果的协同。

Nanobody becomes a novel class of proprietary therapeutic proteins in recent years, which is based on its stable structure, small molecular weight, easy expression and purification, and low immunogenicity. From the perspective of macromolecular self-assembly, nanobody also has a bright future because of these advantages, but unfortunately, the research in this field has not been concerned in any literature. In this project, a new protein-polymer conjugate with novel structure and composition was designed. This new conjugate is constructed by fluorescent proteins and their fusion nanobodies, which were fused with different types of coiled-coil proteins. Through adjusting the type of coiled-coils and the construction of fusion proteins, we could obtain supramolecular polymers, vesicles and protein hydrogels based on these nanobody-polymers. Preliminary results indicated that the protein hydrogel with the ability of recruiting macrophages could specifically induce the migration of immune cells. We plan to further study the molecular mechanism of the cell migration, also apply this migration function to promote the infiltration of effector immune cells into the tumor site, and finally enhance the synergistic effect with the anti-tumor effect of immune checkpoint inhibitors.