{"title":"The inducible secreting TLR5 agonist, CBLB502, enhances the anti-tumor activity of CAR133-NK92 cells in colorectal cancer.","authors":"Xiaohui Wang, Wei Qiu, Haoyu Liu, Min He, Wei He, Zhan Li, Zhiqiang Wu, Xiang Xu, Ping Chen","doi":"10.20892/j.issn.2095-3941.2023.0033","DOIUrl":null,"url":null,"abstract":"<p><strong>Objective: </strong>CAR-T/NK cells have had limited success in the treatment of solid tumors, such as colorectal cancer (CRC), in part because of the heterogeneous nature of tumor-associated antigens that lead to antigen-negative relapse after the initial response. This barrier might be overcome by enhancing the recruitment and durability of endogenous immune cells.</p><p><strong>Methods: </strong>Immunohistochemistry and flow cytometry were used to assess the expression of CD133 antigen in tissue microarrays and cell lines, respectively. Retroviral vector transduction was used to generate CBLB502-secreting CAR133-NK92 cells (CAR133-i502-NK92). The tumor killing capacity of CAR133-NK92 cells <i>in vitro</i> and <i>in vivo</i> were quantified <i>via</i> LDH release, the RTCA assay, and the degranulation test, as well as measuring tumor bioluminescence signal intensity in mice xenografts.</p><p><strong>Results: </strong>We engineered CAR133-i502-NK92 cells and demonstrated that those cells displayed enhanced proliferation (9.0 × 10<sup>4</sup> cells <i>vs</i>. 7.0 × 10<sup>4</sup> cells) and specific anti-tumor activities <i>in vitro</i> and in a xenogeneic mouse model, and were well-tolerated. Notably, CBLB502 secreted by CAR133-i502-NK92 cells effectively activated endogenous immune cells. Furthermore, in hCD133+/hCD133- mixed cancer xenograft models, CAR133-i502-NK92 cells suppressed cancer growth better than the counterparts (<i>n</i> = 5, <i>P</i> = 0.0297). Greater T-cell infiltration was associated with greater anti-tumor potency (<i>P</i> < 0.0001).</p><p><strong>Conclusions: </strong>Armed with a CBLB502 TLR5 agonist, CAR133-NK92 cells were shown to be capable of specifically eliminating CD133-positive colon cancer cells in a CAR133-dependent manner and indirectly eradicating CD133-negative colon cancer cells in a CBLB502-specific endogenous immune response manner. This study describes a novel technique for optimizing CAR-T/NK cells for the treatment of antigenically-diverse solid tumors.</p>","PeriodicalId":9611,"journal":{"name":"Cancer Biology & Medicine","volume":null,"pages":null},"PeriodicalIF":5.6000,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10546094/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cancer Biology & Medicine","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.20892/j.issn.2095-3941.2023.0033","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Objective: CAR-T/NK cells have had limited success in the treatment of solid tumors, such as colorectal cancer (CRC), in part because of the heterogeneous nature of tumor-associated antigens that lead to antigen-negative relapse after the initial response. This barrier might be overcome by enhancing the recruitment and durability of endogenous immune cells.
Methods: Immunohistochemistry and flow cytometry were used to assess the expression of CD133 antigen in tissue microarrays and cell lines, respectively. Retroviral vector transduction was used to generate CBLB502-secreting CAR133-NK92 cells (CAR133-i502-NK92). The tumor killing capacity of CAR133-NK92 cells in vitro and in vivo were quantified via LDH release, the RTCA assay, and the degranulation test, as well as measuring tumor bioluminescence signal intensity in mice xenografts.
Results: We engineered CAR133-i502-NK92 cells and demonstrated that those cells displayed enhanced proliferation (9.0 × 104 cells vs. 7.0 × 104 cells) and specific anti-tumor activities in vitro and in a xenogeneic mouse model, and were well-tolerated. Notably, CBLB502 secreted by CAR133-i502-NK92 cells effectively activated endogenous immune cells. Furthermore, in hCD133+/hCD133- mixed cancer xenograft models, CAR133-i502-NK92 cells suppressed cancer growth better than the counterparts (n = 5, P = 0.0297). Greater T-cell infiltration was associated with greater anti-tumor potency (P < 0.0001).
Conclusions: Armed with a CBLB502 TLR5 agonist, CAR133-NK92 cells were shown to be capable of specifically eliminating CD133-positive colon cancer cells in a CAR133-dependent manner and indirectly eradicating CD133-negative colon cancer cells in a CBLB502-specific endogenous immune response manner. This study describes a novel technique for optimizing CAR-T/NK cells for the treatment of antigenically-diverse solid tumors.
期刊介绍:
Cancer Biology & Medicine (ISSN 2095-3941) is a peer-reviewed open-access journal of Chinese Anti-cancer Association (CACA), which is the leading professional society of oncology in China. The journal quarterly provides innovative and significant information on biological basis of cancer, cancer microenvironment, translational cancer research, and all aspects of clinical cancer research. The journal also publishes significant perspectives on indigenous cancer types in China.