BioRxiv. 2021 Aug 17
Elisa Arthofer, Krishnendu Chakraborty, Lydia Viney, Matthew J Johnson, Beau R. Webber, Branden S. Moriarity, View ORCID ProfileEmil Lou, Modassir Choudhry, Christopher A. Klebanoff, Tom Henley
Products used in the paper Details Operation
AAV vector packaging Viral rAAV6 particles were produced by Vigene Biosciences or PackGene Request Quote

Research Field: immunology

Keywords: CRISPR, immune checkpoint, PD-1, PD-L1, TIGIT, immunotherapy, T Cell Therapy, TIL, TCR, Cancer, CISH

AAV Serotype: AAV6


PD-1 acts as a negative regulator of T cell-mediated immune responses in the setting of persistent antigen expression, including cancer and chronic pathogen infections. Antibody-mediated blockade of the PD-1/PD-L1 axis benefits a subset of patients with highly immunogenic malignancies; however, many patients fail to respond due to a requirement for expression of the cell surface ligand PD-L1 within the tumor microenvironment. CISH is a member of a new class of intra-cellular immune checkpoint molecules that function downstream of the T cell receptor to regulate antigen-specific effector functions, including reactivity to cancer neoantigens. Herein, we employed multiplex CRISPR editing of primary human T cells to systematically compare the function of CISH deletion relative to PDCD1 (the gene encoding PD-1) and/or VSIG9 (the gene encoding TIGIT) in a model of neoantigen41 mediated cancer cell cytolysis. PD-1 and TIGIT disruption enhanced cytolytic activity exclusively in the setting of high PD-L1 expression. In contrast, CISH inactivation enhanced antigen-specific cytolysis of tumor cells regardless of PD-L1 expression, including outperforming PD-1 and TIGIT disruption even in the presence of high PD-L1 tumor cells. Furthermore, we observed a synergistic increase in tumor cell killing when CISH and PD-1 or TIGIT are inactivated in combination, supporting the notion that these immune checkpointsregulate non-redundant pathways of T cell activation. Together, these data demonstrate that the intra-cellular immune checkpoint protein CISH can potentially enhance anti48 tumor responses against a broad range of cancer types regardless of PD-L1 biomarker status.

Popular Services

AAV Packaging Service

AAV Analytical Service

Vector Design