A NEW PHAGE DISPLAY SYSTEM TO CONSTRUCT MULTICOMBINATORIAL LIBRARIES OF VERY LARGE ANTIBODY REPERTOIRES

We present an easy and efficient technique for the construction of large phage-displayed antibody (Ab) repertoires through the recombination of two separate heavy (V-H) and light (V-L) chain gene libraries. Here, the system has been applied to the display of a chimpanzee anti-HIV gp160 Ab, The process, which makes use of lambda phage att recombination sites, leads to the irreversible physical association between plasmid and phagemid vectors carrying, respectively, V-L and V-H sequences. The heat-inducible expression of the Int recombinase allows perfect control of recombination. Selection of the recombinant phagemid is made possible by the assembly, in vivo, of a genetic marker (chloramphenicol resistance) created only after the correct recombination event. Theoretically, all possible associations between the V-L and V-H sequences should be obtained, and it should be possible to generate multicombinatorial libraries of close to 10(12) clones.