Zeno Therapeutics Pte. Ltd.

Epstein-Barr virus (EBV) is an oncovirus belonging to the herpesvirus family, associated with the pathogenesis of multiple malignancies, particularly Burkitt lymphoma (BL). The virus remains latent in host cells and plays a critical role in tumor progression through various mechanisms. A key glycoprotein, gp350, expressed during the lytic phase of EBV, is instrumental in viral entry into B cells and presents a unique antigenic target, making it a promising candidate for immunotherapeutic approaches, such as chimeric antigen receptor T-cell (CAR-T) therapy.

In this study, we engineered CAR-T cells targeted against the gp350 glycoprotein and assessed their therapeutic potential through a series of in vitro and in vivo experiments. The efficacy of the gp350-CAR-T cells was evaluated by comparing their cytotoxic effects against both EBV-positive and -negative tumor cell lines. We utilized a xenograft model of Burkitt lymphoma to monitor the impact of gp350-CAR-T cell administration on tumor progression and overall survival.

The engineered gp350-CAR-T cells demonstrated potent cytotoxicity specifically against EBV-positive tumor cell lines. In our in vivo xenograft model, administration of gp350-CAR-T cells resulted in significant inhibition of tumor growth, highlighting their capability to effectively target and eliminate EBV-positive lymphomas. This selectivity underscores the potential of utilizing gp350 as a specific target for immunotherapy.

Our findings advocate for the clinical application of gp350-directed CAR-T therapy as a prospective treatment strategy for patients with relapsed or refractory EBV-positive tumors. Given the encouraging preclinical results, further research is warranted to optimize CAR-T cell production processes and extend the potential of this therapy to other EBV-associated malignancies, paving the way for improved outcomes in affected patient populations.

The membrane composition of extracellular vesicles (EVs) largely reflects that of the plasma membrane of the cell of origin. We therefore hypothesized that EVs could be used for immunizations to generate monoclonal antibodies against well-known tumor antigens but possibly also against hitherto unknown tumor-associated target molecules. From an immunization experiment, we obtained a monoclonal antibody specific for SRRM2, an RNA-binding protein involved in splicing and a major component of nuclear speckles. Here, we used this antibody to demonstrate that SRRM2 is exposed on the surface of most cancer cell lines from various entities and, even more important, on cancer cells in vivo. Moreover, we demonstrated that SRRM2-specific CAR-T cells are functional in vitro and in vivo. Collectively, we identified SRRM2 as a promising new target molecule exposed on the cancer cell surface and showed that our SRRM2-specific antibody can be used as a basis for the development of new targeted cancer therapies.