Nanodrug modified with engineered cell membrane targets CDKs to activate aPD-L1 immunotherapy against liver metastasis of immune-desert colon cancer.

Immunotherapy based on the PD-1/PD-L1 axis blockade has no benefit for patients diagnosed with colon cancer liver metastasis (CCLM) for the microsatellite stable/proficient mismatch repair (MSS/pMMR)) subtype, which is known as an immune-desert cancer featuring poor immunogenicity and insufficient CD8+ T cell infiltration in the tumor microenvironment. Here, a multifunctional nanodrug carrying a cyclin-dependent kinase (CDK)1/2/5/9 inhibitor and PD-L1 antibody is prepared to boost the immune checkpoint blockade (ICB)-based immunotherapy against MSS/pMMR CCLM via reversing the immunosuppressive tumor microenvironment. To enhance the MSS/pMMR CCLM-targeting efficacy, we modify the nanodrug with PD-L1 knockout cell membrane of this colon cancer subtype. First, CDKs inhibitor delivered by nanodrug down-regulates phosphorylated retinoblastoma and phosphorylated RNA polymerase II and meanwhile arrests the G2/M cell cycle in CCLM to promote immunogenic signal release, stimulate dendritic cell maturation, and enhance CD8+ T cell infiltration. Moreover, CDKi suppresses the secretion of immunosuppressive cytokines in tumor-associated myeloid cells sensitizing ICB therapy in CCLM. Notably, the great efficacy to activate immune responses is demonstrated in the patient-derived xenograft model and the patient-derived organoid model as well, revealing a clinical application potential. Overall, our study represents a promising therapeutic approach for targeting liver metastasis, remolding the tumor immune microenvironment (TIME), and enhancing the response of MSS/pMMR CCLM to boost ICB immunotherapy. Schematic illustration of preparation and CCLM-targeted therapy of engineered cell membrane-camouflaged nanodrug. (A) Preparation of engineered cell membrane-camouflaged nanoparticles co-delivered with CDK inhibitor (CDKi) and anti-mouse/human programmed death ligand 1 antibody (aPD-L1) in response to extracellular acidity of tumor microenvironment. (B) Multifunctional nanodrug targets CDKs in colon cancer cell and tumor-associated myeloid cell (TAMC) to activate aPD-L1 immunotherapy against liver metastasis of immune-desert colon cancer. [Display omitted] [ABSTRACT FROM AUTHOR]