Friday, May 12, 2023     11:15 AM – 12:00 PM ET     Exhibit Hall D, Room 1

Exhibitor Workshop: Miltenyi Biotec

Spatial Characterization and Deep Phenotyping of CD8⁺ Tumor-Infiltrating Lymphocytes in the Tumor Microenvironment

Presenter

• Elvira Criado-Moronati, Team Coordinator in the Personalized Immunotherapy R&D Department

The success of adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) depends on the presence of a sufficient number of tumor-reactive T cell in the final cell product. To enhance the efficacy of ACT, it is necessary to increase the frequency of these cells by introducing an enrichment prior to their ex vivo expansion. The use of surface markers based on a tumor-reactive T cell phenotype is an appealing option, as it is independent of the target an tigen. In this workshop, we will demonstrate how MICS (MACSimaTM Imaging Cyclic Staining), our multiplexed imaging technology, can be utilized to phenotypically characterize TILs in tumor tissues. By using a panel of 98 antibodies, we analyzed the tumor microenvironment (TME) and the phenotype of CD8⁺ TILs in close proximity to tumor cells, which could indicate tumor recognition. Our results confirmed the presence of several cell subsets composing the TME and their spatial distribution in the tissue. CD8⁺ TILs located near tumor cells expressed exhaustion markers associated with tumor reactivity, such as CD137, PD1, CD39, ICOS, and CD103. Further characterization using flow cytometry and single-cell RNA sequencing confirmed the presence of exhausted CD8⁺ TILs that co-expressed these markers. We will demonstrate that cutting-edge technologies like MICS can support the advancement of immunotherapies by providing a comprehensive characterization of the TME and a platform for screening T cell markers at protein level to develop enrichment strategies.