Abstract A162: Cancer-specific T cell receptor isolation for cancer immunotherapy

Malignant cells may be recognised by T cells binding cell surface Class I HLA (Human Leukocyte Antigen)-peptide complexes presenting disease-associated epitopes. Many cancer patients have been shown to generate CD8 cytotoxic T cell responses to tumour-associated antigens. However, this is often insufficient for the immune system to clear tumours, resulting in progression of cancer. This is in part due to the low avidity of these T cells, as well as the ability of cancer cells to develop escape mechanisms to avoid destruction by T cells. To overcome these issues, we have engineered novel, bi-functional protein therapeutics termed ImmTACs (Immune mobilising monoclonal TCR Against Cancer) which re-direct the immune system to target and destroy tumour cells with a high degree of potency and specificity. An ImmTAC comprises a high affinity ‘monoclonal’ T cell receptor (mTCR) targeting a cancer-associated HLA-peptide complex, fused to an anti-CD3 scFv domain which activates an anti-tumour T cell response. In order to produce ImmTACs, we have developed an integrated in-house process leading to the isolation of TCRs specific for validated cancer epitopes. The critical steps in this process are: antigen selection, epitope identification, T cell cloning, TCR isolation and binding to soluble peptide:MHC on Biacore. High affinity ImmTACs are then generated through a process of affinity maturation. We describe the steps leading to cloning of wild type TCRs and present data to illustrate the successful isolation of TCRs as a result of this procedure. Citation Format: Ruth Ryan, Linda Hibbert, Luise Weigand, Samantha Paston, Debbie Baker, Zoe Donnellan, Vanessa Clark, Kathy Hale, Louise Conlon, Joseph Dukes, Caroline Boudousquie, Giovanna Bossi, Emma Hickman, Alex Powlesland, Annelise Vuidepot, Namir Hassan, Bent Jakobsen. Cancer-specific T cell receptor isolation for cancer immunotherapy. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A162.