Abstract B66: An integrated immuno-oncology platform using high-throughput cell based assays, gene editing and genomic screens in immune cells
Authors: Frank An , Kumar Sujatha , Ghirelli Christina , Hoenderdos Kim , Huseni Tabasum , Thibault Lauren , Kifle Lydia , Almog Nava , Zhao Felicia , Scrace Simon , Myaskovsky Anatoly , Lowe Chris , Steiger Janine , McCarthy Nicola , Moore Jonathan 
Published: March 2017

Horizon is establishing a powerful in vitro immuno-oncology platform with the capability to identify combinations of agents that will synergise with checkpoint inhibitors, determine methods for making safer and more effective cell therapies and find novel targets for immuno-therapy. Horizon previously reported the establishment of a platform consisting of a suite of high-throughput cell-based assays modelling a variety of oncology relevant immune reactions. The platform includes primary human immune-cell based assays for T cell activation, Mixed lymphocyte reaction (MLR), Tumor cell lysis, Antibody-dependent cellular cytotoxicity (ADCC), Complement-dependent cytotoxicity (CDC) and Natural killer cell cytotoxicity assays that have been validated with appropriate clinically approved antibodies (e.g. nivolumab, blinotumamab, & rituximab). Miniaturized to a 384-well format and supported by automation at each experimental step the platform is highly customizable in terms of testing agents that either enhance or inhibit immune cell functions. We will present ongoing efforts to identify synergistic activities with other relevant therapeutics likely to bring benefits to patients. In addition to the continued development of our high throughput immuno-oncology cell based assays, we have expanded our cell engineering know how combined with CRISPR-Cas9 gene editing technology to build new models to understand better the immune response and its subversion in tumorigenesis. By modifying specific genes of interest in immune cells we aim to robustly identify and validate new targets for the clinic. For example, we have used high efficiency gene editing with CRISPR-Cas9 in human primary T cells to knock out and knock in genes using Neon transfection systems. Using this methodology we can rapidly generate primary T cell models lacking specific checkpoint proteins (such as PD-1) to better understand how T-cell signalling pathways interact and to nominate novel targets suitable for ex vivo gene editing. We have also employed pooled CRISPR-Cas9 screens to investigate the effects of metabolic changes on T cell biology. CD3+ T cells have been infected with a one vector lentiviral system that delivers both Cas9 and sgRNAs targeting genes involved in cellular metabolism. Results from these screens should identify potential targets involved in T cell metabolism that affect their capacity to respond to proliferative stimuli in the form of anti-CD3 and anti-CD28 antibodies. We anticipate that these and other data generated using libraries targeting essential genes will be invaluable for the design of more complex immuno-oncology screens. Overall, Horizon's integrated immuno-oncology platform will enable large scale interrogation of prospective immunotherapies, either alone or in combination, and could be useful for the discovery of novel checkpoint components, for deciphering the underlying mechanisms promoting an immunosuppressive tumor microenvironment and for the understanding of how pathways crucial for an anti-tumor immune response interact. Thus, this platform could contribute substantially to the discovery and development of future immunotherapies.

Citation Format: An Frank, Sujatha Kumar, Christina Ghirelli, Kim Hoenderdos, Tabasum Huseni, Lauren Thibault, Lydia Kifle, Nava Almog, Felicia Zhao, Simon Scrace, Anatoly Myaskovsky, Chris Lowe, Janine Steiger, Nicola McCarthy, Jonathan Moore. An integrated immuno-oncology platform using high-throughput cell based assays, gene editing and genomic screens in immune cells. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B66.