Directed selection of MIP-1α neutralizing CCR5 antibodies from a phage display human antibody library

摘要

The seven trans-membrane chemokine receptor CCR-5 is a coreceptor for macrophage tropic HIV-1 strains. CCR-5 responds to a number of chemokines, including macrophage inflammatory protein (MIP)-1α. We describe the use of MIP-1α in a biotin tyramine-mediated proximity selection to guide the selection of CCR-5-specific phage antibodies from a large phage display human library. Proximity based selections resulted in a population of antibodies recognizing CCR-5 on primary CD4~+ lymphocytes, none of which blocked MIP-1α binding to cells. The selected population of phage antibodies were subsequently used as guide molecules for a second phase of selection that was carried out in the absence of MIP-1α. This generated a panel of CCR-5-binding antibodies, of which around 20% inhibited MIP-1α binding to CD4~+. The single chain Fvs (scFv) generated by this step-back selection procedure also inhibited MIP-1α-mediated calcium signaling.