Prosthetic Antigen Receptors

Abstract

Chimeric antigen receptors (CARs) have shown great promise for the immunological treatment of cancer. Nevertheless, the need to genetically engineer a patient's T-cells has presented significant production and safety challenges. To address these issues, we have demonstrated that chemically self-assembled nanorings (CSANs) displaying single chain antibodies can bind to both the CD3 ε subunit of the T-cell-receptor/CD3 complex and the CD22 antigen on malignant B cells such as B-leukemias or lymphomas. We demonstrate that the multivalent and bispecific format allows the antiCD3/antiCD22 CSANs to stably bind to T-cell surfaces for greater than 4 days, while being easily disassembled on the cell membrane by treatment with the nontoxic FDA approved drug, trimethoprim. In the presence of CD22+ Raji cells, T-cells modified with antiCD3/antiCD22 CSANs were shown to selectively up-regulate the production of interleukin-2 (IL-2) and interferon-γ (IFN-γ) and to initiate cytotoxicity. Taken together, our results demonstrate that antiCD3/antiCD22 bispecific CSANs offer a potential alternative to CARs, as prosthetic antigen receptors.