Abstract 1711: Immunoprofiling of precision-cut cancer tissue slices (PCCTS) as a tool for cancer immunotherapy
Authors: Grabinski Nicole , Bernoth Kristina , Leusmann Aljoscha , Fleischhauer-Biermann Carolin , Wendt Dorte , Piller Mirja , Petersen Moiken , Lange Nicole , Tiedemann Anna , Schoeppler Monika , Juhl Hartmut , Helftenbein Gerd , Miegel Andrea , Schnieders Frank , David Kerstin 
Published: August 2018

Abstract
The recent advances in immunotherapies, such as immune checkpoint modulators, bispecific antibodies, and adoptive T-cell transfer, opens new opportunities for the treatment of cancer. Having this broad spectrum of new therapeutic agents available, the demand for predictive and robust preclinical models to minimize translational failures in immuno-oncology is increasing. Indivumed has successfully implemented a model of Precision Cut Cancer Tissue slices (PCCTS) derived from viable human tumor tissue for different applications such as chemotherapeutic agents, small molecules and antibodies. In this study, we investigated the effects of OKT3® on cancer tissue slices especially in respect of gene expression changes and cytokine release.
Fresh tumor pieces from three colorectal cancer patients were cut into 400 µm slices using a Krumdieck Tissue Slicer®. PCCTS were incubated for 4 h and 24 h with and without OKT3®, (Muromonab), a therapeutic antibody against CD3. After defined time points, slices were frozen, and the supernatants were collected. In addition, a second set of slices was formalin fixed and paraffin embedded for immunohistochemical analysis of T-cells. RNA isolated from frozen slices was used for library preparation with the TruSeq Stranded mRNA Library Preparation Kit followed by sequencing on a NextSeq 500 device from Illumina. The results generated by different software tools showed a background of gene expression changes caused by cultivation. On the other hand, a very specific up-regulation of genes was detectable after OKT3® treatment. Especially an induction of genes involved in immune related functions, such as IFN gamma and IL-12 signaling was seen. The analysis of cytokines in the supernatants using a ten-plex panel form Meso Scale Discovery confirmed the activation of T-cells after OKT3® treatment. In all three patients a significant increase of IFN gamma, IL-2, and TNF alpha was measured, comparable to a so called “cytokine storm” that is described in literature. The intensity of the effects correlated to the amount of tumor infiltrating T-cells, quantified by anti-CD3 staining in tissue sections.
This model of PCCTS represents a unique opportunity to test immune-modulatory compounds in a fully human, patient derived model that is close to the in vivo situation. The data of this study shows that profiling of the immune response by RNA-Seq can be successfully performed. In addition to gene expression changes that occur after treatment, deconvolution based approaches to quantify tumor Infiltrating lymphocytes (TILs) from RNA-Seq data will be a key parameter to personalize the treatment of patients.
Citation Format: Nicole Grabinski, Kristina Bernoth, Aljoscha Leusmann, Carolin Fleischhauer-Biermann, Dorte Wendt, Mirja Piller, Moiken Petersen, Nicole Lange, Anna Tiedemann, Monika Schoeppler, Hartmut Juhl, Gerd Helftenbein, Andrea Miegel, Frank Schnieders, Kerstin David. Immunoprofiling of precision-cut cancer tissue slices (PCCTS) as a tool for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1711.