背景:p53是癌症中最常见的突变基因,缺乏有效的靶向药物。
方法:我们开发了针对p53热点突变E285K的单克隆抗体(mAb),与野生型p53没有交叉反应性。使用包封DNA质粒的脂质纳米颗粒(LNP)递送它们。蛋白质印迹,BLI,流式细胞术,单细胞测序(scRNA-seq),和其他方法用于评估mAb在体外和体内的功能。
结果:这些IgG1形式的LNP-pE285K-mAb表现出强大的抗肿瘤作用,促进免疫细胞的浸润,包括CD8+T,B,NK细胞scRNA-seq显示IgG1减少免疫抑制信号,增加MHC信号从B细胞到CD8+T细胞,并丰富抗肿瘤T细胞和B细胞受体谱。E285K-mAb也以二聚体IgA(dIgA)形式产生,其抗肿瘤活性依赖于聚合免疫球蛋白受体(PIGR),膜Ig受体,而IgG1依赖于TRIM21,一种细胞内IgG受体.
结论:使用DNA编码和LNP递送的mAb靶向特异性突变表位代表了针对TRIM21或PIGR阳性癌症中p53突变体的潜在精准医学策略。
BACKGROUND: p53, the most frequently mutated gene in cancer, lacks effective targeted drugs.
METHODS: We developed monoclonal antibodies (mAbs) that target a p53 hotspot mutation E285K without cross-reactivity with wild-type p53. They were delivered using lipid nanoparticles (LNPs) that encapsulate DNA plasmids. Western blot, BLI, flow cytometry, single-cell sequencing (scRNA-seq), and other methods were employed to assess the function of mAbs in vitro and in vivo.
RESULTS: These LNP-pE285K-mAbs in the
IgG1 format exhibited a robust anti-tumor effect, facilitating the infiltration of immune cells, including CD8+ T, B, and NK cells. scRNA-seq revealed that
IgG1 reduces immune inhibitory signaling, increases MHC signaling from B cells to CD8+ T cells, and enriches anti-tumor T cell and B cell receptor profiles. The E285K-mAbs were also produced in the dimeric IgA (dIgA) format, whose anti-tumor activity depended on the polymeric immunoglobulin receptor (PIGR), a membrane Ig receptor, whereas that of
IgG1 relied on TRIM21, an intracellular IgG receptor.
CONCLUSIONS: Targeting specific mutant epitopes using DNA-encoded and LNP-delivered mAbs represents a potential precision medicine strategy against p53 mutants in TRIM21- or PIGR-positive cancers.