摘要

    在过去的十年中，招募针对癌细胞的内源性抗体已成为可靠的抗肿瘤免疫治疗替代方案。事实证明，抗体和肿瘤结合模块（ABM和TBM）在单个明确定义的合成分子中的共价结合可促进抗体和靶细胞之间相互作用的三元复合物的形成，这通常导致同时发生。免疫介导的细胞破坏。在一项初步研究中，我们描述了首个抗体募集糖原蛋白（ARG），将cRGD作为表达αVβ3的黑色素瘤细胞系M21的配体和将Rha作为天然IgM的配体相结合，并证明了多价是形成这种复合物的必要条件。在本研究中，我们合成了由ABM组成的一系列新的ARG，即自缩合的鼠李糖基化环肽和聚赖氨酸树状大分子，它们已经或不与间隔基共轭到TBM。用人血清和不同细胞系进行的流式细胞术和共聚焦显微镜实验表明，ABM几何形状显着影响M21中的三元复合物形成，而在整合素表达低的BT 549中则没有明显的结合。此外，我们通过细胞生存力试验证明ARGs诱导了针对M21的高水平细胞毒性，这也与ABM结构密切相关。特别是，我们已经证明，在存在人血清作为免疫效应物的唯一来源的情况下，结合环肽核心和分支（有或没有间隔子）的ARG可以诱导针对M21细胞的40-57％的选择性细胞毒性。最后，我们还强调了即使在价较低的ABM的情况下，ABM与TBM之间的间隔子也可以提高免疫介导的细胞毒性。

    The recruitment of endogenous antibodies against cancer cells has become a reliable antitumoral immunotherapeutic alternative over the last decade. The covalent attachment of antibody and tumor binding modules (ABM and TBM) within a single, well-defined synthetic molecule was indeed demonstrated to promote the formation of an interacting ternary complex between both the antibodies and the targeted cell, which usually results in the simultaneous immune-mediated cellular destruction. In a preliminary study, we have described the first Antibody Recruiting Glycodendrimers (ARGs), combining cRGD as ligands for the αVβ3-expressing melanoma cell line M21 and Rha as ligand for natural IgM, and demonstrated that multivalency is an essential requirement to form this complex. In the present study, we synthesized a new series of ARGs composed of ABMs, i.e. self-condensed rhamnosylated cyclopeptide and polylysine dendrimer, which have been conjugated to the TBM with or without spacer. Flow cytometry and confocal microscopy experiments with human serum and different cell lines revealed that the ABM geometry significantly influences the ternary complex formation in M21, whereas no significant binding occurs in BT 549 having low integrin expression. In addition, we demonstrate with a cellular viability assay that ARGs induce high level of cytotoxicity against M21 which is also in close correlation with the ABM structure. In particular, we have shown that ARG combining cyclopeptide core and branches, with or without spacer, induce 40–57% of selective cytotoxicity against M21 cells in the presence of human serum as the unique source of immunity effectors. Finally, we also highlight that the spacer between ABM and TBM enables an increase of the immune-mediate cytotoxicity even with ABM of lower valency.

    https://pubs.rsc.org/en/content/articlelanding/2021/bm/d1bm00485a/unauth#!divAbstract