Affinity chromatography of CD4 ligands.

A key step in the infection of T cells by HIV-1 is the interaction between the cellular receptor CD4 and the viral envelope protein gp120. Various compound of potential pharmacological value have been tested for their ability to interfere with this interaction with aim of identifying drugs that reduce virus infectivity. In particular, monoclonal antibodies directed agianst the gp120-binding domain of CD4 and gp120 derived synthetic peptides which bind to CD4 can be used to modulate the immunoresponse and block HIV-1 infectivity. We report an affinity chromatography assay, which, in combination with epitope-specific anti-CD4 mAbs, may allow the rapid identification of ligands recognized by CD4 and their cognate binding sites. This method should facilitate the design of analogues exhibiting a higher affinity or selectivity for the protein thus restricting the number of potentially useful compounds to be tested in more sophisticated assays.