SEQUENCE AND STRUCTURE-SPECIFIC ANTIBODIES FROM PHAGE DISPLAY LIBRARIES

A large combinatorial phage display library was panned against five nu cleic acid antigens, calf thymus DNA, poly[d(GC)], poly[d(AT)], poly(d A).poly(dT) and poly(rA).poly(dT). After the third and fourth rounds o f panning, many positive clones were selected against poly[d(GC)], pol y(dA). poly(dT) and poly(rA).poly(dT). The specificity of these antibo dies was tested by both direct and competitive solid phase radioimmune assays. All the clones derived from panning with poly[d(GC)] were non -specific and bound to all nucleic acids. The poly(rA).poly(dT) derive d clones were specific for single-stranded nucleic acids, with some se quence preferences, and the poly(dA).poly(dT) derived clones showed co nsiderable specificity for this antigen. The sequences of these phage- derived antibodies showed no similarities with DNA-binding antibodies from other sources. Even after six rounds of panning no positive clone s were detected which bound to poly[d(AT)] and after seven rounds only two were derived from panning with calf thymus DNA. Therefore, sequen ce- and structure specific antibodies can be recovered from phage disp lay libraries but not all sequences may be represented in the repertoi re. (C) 1997 Published by Elsevier Science Ltd.