Generation of a murine single chain Fv (scFv) antibody specific for cucumber mosaic virus (CMV) using a phage display library

With the long-term goal of generating CMV-resistant transgenic plants using antibody genes, a single-chain variable fragment (scFv) antibody that bind s to the cucumber mosaic virus was isolated from a scFv phage display libra ry by four rounds of affinity selection with CMV-Mf as an antigen. The scFv has the identical binding specificity to CMV as a monoclonal antibody that is generated by the hybridoma fusion technique, and recognized purified pr eparations of CMV isolates belonging to either subgroup I or II in immunobl otting. The nucleotide sequences of the recombinant antibody showed that a heavy chain variable region (VH) gene belonged to the V(H)3 subgroup and th e kappa light chain variable region (V kappa) came from the V(K)4 subgroup. Our results demonstrate that the scFv phage display library, an alternativ e approach to the traditional hybridoma fusion technique, has a potential a pplicability in the study of plant virus and plant pathology.