CUCUMBER MOSAIC CUCUMOVIRUS ANTIBODIES FROM A SYNTHETIC PHAGE DISPLAYLIBRARY

Antibody fragments (scFv) that bind specifically to particles of cucum ber mosaic cucumovirus (CMV) were obtained from a library which encode s a diverse array of synthetic antibody fragments, each displayed on t he surface of filamentous bacteriophage. After four rounds of selectio n and enrichment, several clones were obtained which produced scFv tha t bound specifically to purified particles of CMV in ELISA. BstNI dige stion of phagemid DNA resulted in the same restriction pattern for all clones. The nucleotide sequences of three of the clones showed that t hey belonged to the human V(H)1 family and that they had a complementa rity determining region loop of 7 amino acids. Phage-displayed antibod ies and soluble scFv secreted by these clones reacted with particles o f CMV in sap from infected plants in ELISA. In immunoblotting tests, s oluble scFv preparations reacted with SDS-denatured coat protein extra cted from purified preparations of CMV isolates belonging to either su bgroup I or II and also with protein extracted by sos treatment of see ds harvested from naturally infected lupin plants. The results demonst rate the feasibility, and potential applicability, of recombinant anti body methods in plant pathology. (C) 1995 Academic Press, Inc.