p53, the most frequently mutated gene in cancer, lacks effective targeted drugs. 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. 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. 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.

中文翻译：

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用靶向 p53 突变体的抗体重塑抗肿瘤免疫


p53 是癌症中最常突变的基因，缺乏有效的靶向药物。我们开发了靶向 p53 热点突变 E285K 的单克隆抗体 （mAb），与野生型 p53 无交叉反应性。它们是使用封装 DNA 质粒的脂质纳米颗粒 （LNP） 递送的。采用 Western blot、BLI、流式细胞术、单细胞测序 （scRNA-seq） 和其他方法评估 mAb 在体外和体内的功能。这些 IgG1 形式的 LNP-pE285K-mAb 表现出强大的抗肿瘤作用，可促进免疫细胞（包括 CD8+ T、B 和 NK 细胞）的浸润。scRNA-seq 显示 IgG1 减少免疫抑制信号传导，增加从 B 细胞到 CD8+ T 细胞的 MHC 信号传导，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，其抗肿瘤活性取决于膜 Ig 受体聚合物免疫球蛋白受体 （PIGR），而 IgG1 的抗肿瘤活性依赖于细胞内 IgG 受体 TRIM21。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。