嵌合抗原受体（CAR-T）疗法对实体肿瘤的治疗效果有限，主要是由于CAR-T细胞在实体肿瘤中的浸润有限以及免疫抑制性肿瘤微环境对CAR-T细胞的失活。巨噬细胞是先天和适应性免疫的重要组成部分，其独特的吞噬功能已被用于构建针对实体肿瘤的CAR巨噬细胞（CAR-Ms）。本研究旨在探索CAR-M在卵巢癌治疗中的应用。在本研究中，我们构建了新的CAR结构，包括人源化的抗HER2或CD47 scFv、CD8铰链区和跨膜区，以及4-1BB和CD3ζ细胞内结构域。我们检测了HER2 CAR-M和CD47 CAR-M对卵巢癌细胞的吞噬作用以及对适应性免疫的促进作用。我们使用了两种同种移植瘤模型来评估HER2 CAR-M和CD47 CAR-M的体内抗肿瘤活性。我们构建了针对HER2和CD47的CAR-M，并验证了它们在体内和体外对卵巢癌细胞的吞噬能力。构建的CAR-M在体外显示出对卵巢癌细胞的特异性吞噬作用，并能够激活CD8+细胞毒性T淋巴细胞（CTL）分泌多种抗肿瘤因子。对于体内模型，我们使用了具有人类免疫系统的小鼠。我们发现CAR-M增强了CD8+ T细胞的活化，影响了肿瘤相关巨噬细胞（TAM）的表型，并导致肿瘤的回归。我们证明了我们构建的新型HER2 CAR-M和CD47 CAR-M对靶抗原阳性的卵巢癌在体外和体内的抑制作用，并初步验证了这种抑制作用是由于吞噬作用、对适应性免疫的促进作用和对肿瘤微环境的影响。 © 2023. BioMed Central Ltd., part of Springer Nature.

The chimeric antigen receptor (CAR)-T therapy has a limited therapeutic effect on solid tumors owing to the limited CAR-T cell infiltration into solid tumors and the inactivation of CAR-T cells by the immunosuppressive tumor microenvironment. Macrophage is an important component of the innate and adaptive immunity, and its unique phagocytic function has been explored to construct CAR macrophages (CAR-Ms) against solid tumors. This study aimed to investigate the therapeutic application of CAR-Ms in ovarian cancer.In this study, we constructed novel CAR structures, which consisted of humanized anti-HER2 or CD47 scFv, CD8 hinge region and transmembrane domains, as well as the 4-1BB and CD3ζ intracellular domains. We examined the phagocytosis of HER2 CAR-M and CD47 CAR-M on ovarian cancer cells and the promotion of adaptive immunity. Two syngeneic tumor models were used to estimate the in vivo antitumor activity of HER2 CAR-M and CD47 CAR-M.We constructed CAR-Ms targeting HER2 and CD47 and verified their phagocytic ability to ovarian cancer cells in vivo and in vitro. The constructed CAR-Ms showed antigen-specific phagocytosis of ovarian cancer cells in vitro and could activate CD8+ cytotoxic T lymphocyte (CTL) to secrete various anti-tumor factors. For the in vivo model, mice with human-like immune systems were used. We found that CAR-Ms enhanced CD8+ T cell activation, affected tumor-associated macrophage (TAM) phenotype, and led to tumor regression.We demonstrated the inhibition effect of our constructed novel HER2 CAR-M and CD47 CAR-M on target antigen-positive ovarian cancer in vitro and in vivo, and preliminarily verified that this inhibitory effect is due to phagocytosis, promotion of adaptive immunity and effect on tumor microenvironment.© 2023. BioMed Central Ltd., part of Springer Nature.