Article
Author: Crispe, Ian Nicholas ; Labadie, Kevin P ; Park, James O ; Jiang, Xiuyun ; Chan, Marina ; Kim, Teresa S ; Yeung, Raymond S ; Daniel, Sara K ; Lausted, Christopher ; Hsu, Cynthia ; Kohli, Karan ; Sullivan, Kevin M ; Gujral, Taranjit S ; Tian, Qiang ; Kenerson, Heidi L ; Yan, Xiaowei ; Meng, Changting ; Seo, Y David ; Abbasi, Arezou ; Katz, Steven C ; Pillarisetty, Venu G ; Guha, Prajna ; Carter, Jason A
ObjectiveProgrammed cell death protein 1 (PD-1) checkpoint inhibition and adoptive cellular therapy have had limited success in patients with microsatellite stable colorectal cancer liver metastases (CRLM). We sought to evaluate the effect of interleukin 10 (IL-10) blockade on endogenous T cell and chimeric antigen receptor T (CAR-T) cell antitumour function in CRLM slice cultures.DesignWe created organotypic slice cultures from human CRLM (n=38 patients’ tumours) and tested the antitumour effects of a neutralising antibody against IL-10 (αIL-10) both alone as treatment and in combination with exogenously administered carcinoembryonic antigen (CEA)-specific CAR-T cells. We evaluated slice cultures with single and multiplex immunohistochemistry, in situ hybridisation, single-cell RNA sequencing, reverse-phase protein arrays and time-lapse fluorescent microscopy.ResultsαIL-10 generated a 1.8-fold increase in T cell-mediated carcinoma cell death in human CRLM slice cultures. αIL-10 significantly increased proportions of CD8+T cells without exhaustion transcription changes, and increased human leukocyte antigen - DR isotype (HLA-DR) expression of macrophages. The antitumour effects of αIL-10 were reversed by major histocompatibility complex class I or II (MHC-I or MHC-II) blockade, confirming the essential role of antigen presenting cells. Interrupting IL-10 signalling also rescued murine CAR-T cell proliferation and cytotoxicity from myeloid cell-mediated immunosuppression. In human CRLM slices, αIL-10 increased CEA-specific CAR-T cell activation and CAR-T cell-mediated cytotoxicity, with nearly 70% carcinoma cell apoptosis across multiple human tumours. Pretreatment with an IL-10 receptor blocking antibody also potentiated CAR-T function.ConclusionNeutralising the effects of IL-10 in human CRLM has therapeutic potential as a stand-alone treatment and to augment the function of adoptively transferred CAR-T cells.