The goal of these studies is to evaluate the feasibility of using a T-cell receptor based fusion protein as a targeting agent for therapies for CMV, which remains a major cause of morbidity and mortality inimmunocompromised patients. For these studies a TCR recognizing a distinct, naturally processed, highly immunogenic peptide fragment from the human cytomegalovirus tegument protein pp65 presented on the cell surface in the context of HLA-A2 was cloned. This TCR was isolated from CMV peptide specific CD8+ T-cells that were generated by CMV peptide stimulation of HLA-A2 positive human PBMC. A CMV specific single chain TCR/IgG1 fusion protein, CMVscTCR/IgG1, was prepared and will be expressed at high levels in mammalian cells and purified for characterization. The fusion protein will be characterized in vitro for MHC restricted peptide specific binding, stability, affinity, ability to target antigen positive cells, and ability to conjugate target and effector cells. Finally, the CMVscTCR/IgG1 fusion protein will be evaluated in vivo for pharmacokinetics and toxicity. Successful completion of these studies will lead to in vivo efficacy studies in a novel mouse model of human CMV infection and to eventual production of TCR-based targeted CMV therapeutics for commercialization.
