Using a series of new insertion/expression vectors, we constructed a set of recombinant vaccinia viruses (recVV) encoding the murine T cell costimulatory molecules mB7-1 or mB7-2, or both together in the same construct. On infection with replication incompetent and non-cytopathic recVV, several tumour cell lines expressed the respective molecules and bound to CTLA-4. The highest binding capacity was found when both mB7 molecules were co-expressed. Mouse B16.F10 melanoma cells expressing mB7-1 or mB7-2 provided effective costimulation for proliferation of resting CD4+ T cells in the presence of concanavalin A and plate-bound anti-T cell receptor antibodies, respectively. If mB7-1 and mB7-2 were delivered together on the same cell, the proliferative response of CD4+ T cells increased further. The costimulatory effect could be blocked with CTLA-4, the soluble ligand for B7 molecules. The possibility of engineering tumour cells using recVV holds implications for the future design of vaccination strategies.
View details for Web of Science ID A1996WB25100027
View details for PubMedID 9000106