Colorectal cancer interleukin-10 blockade scRNA-seq

Objective: PD-1 checkpoint inhibition and adoptive cellular therapy have
limited success in patients with microsatellite stable colorectal cancer
liver metastases (CRLM). We demonstrate that interleukin-10 (IL-10)
blockade enhances endogenous T cell and chimeric antigen receptor T
(CAR-T) cell anti-tumor function in CRLM slice cultures.Design: We created
organotypic slice cultures from human CRLM (n = 38) and tested the
anti-tumor effects of a neutralizing antibody against IL-10 (αIL-10). We
evaluated slice cultures with single and multiplex immunohistochemistry,
in situ hybridization, single cell RNA sequencing, and time-lapse
fluorescent microscopy. In addition, we studied the effects of αIL-10 on
carcinoembryonic antigen (CEA)-specific CAR-T cells exogenously
administered to both human CRLM slice cultures and a CRLM murine model.
Results: There was little effect of PD-1 blockade in CRLM slice cultures.
In contrast, αIL-10 generated 1.8-fold increase in T cell-mediated
carcinoma cell death, and increased proportion of CD8+ T cells and
inflammatory polarization of macrophages. In addition to effects on
endogenous immune cells in human CRLM, αIL-10 also rescued murine CAR-T
cell proliferation and cytotoxicity from myeloid cell-mediated
immunosuppression. In human CRLM slices, αIL-10 dramatically improved
CEA-specific CAR-T cell cytotoxicity, generating nearly 70% carcinoma
apoptosis across multiple human tumors. We saw a less dramatic, but
similar effect of pretreatment of CAR-T cells with an IL-10 receptor
blocking antibody, demonstrating that IL-10 inhibits CAR-T function in the
CRLM tumor microenvironment. Conclusion: Neutralizing 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.