本研究的目的是提高 CLDN18.2/CD3 双特异性 T 细胞接合剂 (BiTE) 作为一种有前途的胰腺导管腺癌 (PDAC) 免疫疗法的疗效。人源化 hCD34 /hCD3e、Trp53R172HKrasG12DPdx1-Cre (KPC)、胰腺-构建了特异性 Cldn18.2 敲除 (KO)、成纤维细胞特异性 Fcgr1 KO 和患者来源的异种移植/类器官小鼠模型。进行流式细胞术、Masson染色、Cell Titer Glo测定、虚拟药物筛选、分子对接和染色质免疫沉淀。CLDN18.2 BiTEs有效抑制早期肿瘤生长，但晚期疗效明显减弱。从机械角度来看，BiTE 的 Fc 片段通过激活 SYK-VAV2-RhoA-ROCK-MLC2-MRTF-A-α-SMA/胶原蛋白-I 途径与 CD64 癌症相关成纤维细胞 (CAF) 相互作用，从而增强结缔组织形成并限制晚期纤维化。 T细胞阶段浸润。分子对接分析发现，维兰特罗抑制 BiTE 诱导的 CD64 CAF 中 VAV2 (Y172) 的磷酸化，并减弱结缔组织形成。此外，环鸟苷-腺苷单磷酸合酶/干扰素基因刺激剂 (STING) 活性的降低减少了 TCF-1 PD-1 干细胞样 CD8 T 细胞的增殖，从而限制了 BiTE 的后期效应。最后，维兰特罗和 STING 激动剂通过抑制 CD64 CAF 的激活和丰富干细胞样 CD8 T 细胞的增殖，协同增强 BiTE 的功效，从而产生持续的抗肿瘤活性。维兰特罗和 STING 激动剂使 PDAC 对 CLDN18.2 敏感。 BiTE 和增强功效作为一种潜在的新颖策略。© 作者（或其雇主）2024。禁止商业重复使用。请参阅权利和权限。英国医学杂志出版。

The objective of this study is to improve the efficacy of CLDN18.2/CD3 bispecific T-cell engagers (BiTEs) as a promising immunotherapy against pancreatic ductal adenocarcinoma (PDAC).Humanised hCD34+/hCD3e+, Trp53R172HKrasG12DPdx1-Cre (KPC), pancreas-specific Cldn18.2 knockout (KO), fibroblast-specific Fcgr1 KO and patient-derived xenograft/organoid mouse models were constructed. Flow cytometry, Masson staining, Cell Titer Glo assay, virtual drug screening, molecular docking and chromatin immunoprecipitation were conducted.CLDN18.2 BiTEs effectively inhibited early tumour growth, but late-stage efficacy was significantly diminished. Mechanically, the Fc fragment of BiTEs interacted with CD64+ cancer-associated fibroblasts (CAFs) via activation of the SYK-VAV2-RhoA-ROCK-MLC2-MRTF-A-α-SMA/collagen-I pathway, which enhanced desmoplasia and limited late-stage infiltration of T cells. Molecular docking analysis found that vilanterol suppressed BiTEs-induced phosphorylation of VAV2 (Y172) in CD64+ CAFs and weakened desmoplasia. Additionally, decreased cyclic guanosine-adenosine monophosphate synthase/stimulator of interferon genes (STING) activity reduced proliferation of TCF-1+PD-1+ stem-like CD8+ T cells, which limited late-stage effects of BiTEs. Finally, vilanterol and the STING agonist synergistically boosted the efficacy of BiTEs by inhibiting the activation of CD64+ CAFs and enriching proliferation of stem-like CD8+ T cells, resulting in sustained anti-tumour activity.Vilanterol plus the STING agonist sensitised PDAC to CLDN18.2 BiTEs and augmented efficacy as a potential novel strategy.© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.