A NOVEL-APPROACH TO HUMAN ANTI-HLA MABS PRODUCTION - USE OF PHAGE DISPLAY LIBRARIES

The production of human monoclonal antibodies was previously limited t o very laborious and time-consuming processes involving EBV-transforma tion and/or hybridoma generation. Due to the development of molecular cloning techniques, it, is now possible to produce human monoclonal an tibody fragments quickly by panning phage display libraries against pr edefined antip genic specificities. Therefore, we tested this technolo gy for producing human single chain Fv fragments (scFvs) purified mole cules immobilized on solid phase. Enrichment of DR1-specific phages wa s measured through five selection rounds of a synthetic library and re vealed a 100-fold amplification. Soluble antibody fragments were then expressed and 7 out of 48 clones were found to secrete scFvs which spe cifically bind ro DR1 molecules in ELISA. Further analysis revealed bi nding of the scFvs also to DR3 but not to DR5 or DR7 molecules correla ting with the presence of particular polymorphic aminoacid residues in the DR beta chain. Western blot analysis indicated that the 7 scFvs r eact with the DR1 alpha/beta-dimer but not with free alpha- or beta-ch ains. This study shows that, the innovative approach of phage display libraries can efficiently provide scFv fragments as useful reagents fo r the identification and dissection of HLA polymorphic epitopes. (C) A merican Society for Histocompatibility and Immunogenetics, 1997. Publi shed by Elsevier Science Inc.