A bidirectional phage display vector for the selection and mass transfer of polyclonal antibody libraries

An approach to the creation of antigen-specific polyclonal libraries of int act antibodies is presented. A polyclonal library of Fab antibody fragments would be expressed using a phage display vector, and selected for reactivi ty with an antigen or group of antigens, For conversion into a sublibrary o f intact polyclonal antibodies, the selected heavy (H) and light (L) chain variable (V) region gene combinations would be transferred in mass, as link ed pairs, to a eukaryotic expression vector which provides immunoglobulin ( Ig) constant (C) region genes. To enable this selection and transfer, a bid irectional phage display vector was generated, in which the V region gene p airs are linked head to head in opposite transcriptional orientations. The functionality of this vector was demonstrated by the selection, transfer an d expression of linked V region gene pairs derived from an A/J mouse that h ad been immunized with p-azophenylarsonate (Ars)-coupled keyhole limpet hem ocyanin (KLH). As expected, the expressed IgG2b anti-Ars antibodies with se lected V region gene pairs were shown to have V region sequences and Ars-bi nding characteristics similar to those of anti-Ars hybridoma antibodies. Th e technology presented here has potential for many diagnostic and therapeut ic applications. These include the generation of polyclonal antibody librar ies against multiple epitopes on infectious agents or cancer cells, and of polyclonal libraries encoding chimeric molecules composed of antibody V reg ions and T cell receptor C regions. (C) 1999 Elsevier Science B.V. All righ ts reserved.