PHAGE-DISPLAYED FAB FRAGMENTS AGAINST ANTI-HUMAN INTERLEUKIN-2 RECEPTOR-ALPHA - DETECTION OF ANTIGEN-BOUND PHAGES WITH ANTI-CPIII MONOCLONAL-ANTIBODIES

The genes encoding the VHCHl and VLCL parts of the mouse anti-human IL -2R alpha antibody 7G7B6 were amplified by PCR and the corresponding a ntibody fragments displayed on the surface of filamentous phages. The expression of Fab fragments was analysed by immunoblotting using HRP-l abelled goat anti-mouse Ig antisera. By traditional hybridoma technolo gy, splenocytes from Balb/c mice, immunized with native phage particle s, were fused with P3X63-Ag8.653 myeloma cells in order to yield monoc lonal antibodies against filamentous phage proteins. The obtained mono clonal antibody IF8 (mu/kappa) recognized the minor coat protein III a s a 65-70 kDa protein band by immunoblotting, whereas the monoclonal a ntibody IVC8 (mu/kappa), in addition to cpIII, recognized a protein wi th an approximate molecular weight of 38-43 kDa. Both antibodies were employed to determine the binding specificity of the phage-displayed a nti-human IL-2R alpha Fab fragments in an ELISA using recombinant bacu lovirus-expressed human IL-2R alpha proteins as antigens.