It is proposed to develop an affinity adsorbent system which can be used to remove HIV-1 antigens and/or virus from solution. The membrane will use a novel ligand, namely the T lymphocyte CD4 receptor for the HIV-1. This protein has recently been cloned and expressed as a fully soluble 50 kd protein which can combine specifically in solution with the gp120 env protein of HIV-1. The experimental plan will be to use novel chemical modification protocols to immobilize this protein on solid phase membrane materials. The immobilized receptor will be fully characterized according to its binding affinity and specificity for purified gp120 and HIV-1 as compared to other viruses which are found in blood (e.g., Epstein Barr, Cytomegalovirus). We will also attempt to use synthetic peptides, the sequence of which is based on the sequence of the HIV env proteins, to ascertain in competition experiments the active center of the viral receptor. These results should provide the experimental basis for designing HIV-1 specific blood compatible filter or adsorbent materials which could be introduced at appropriate steps in the blood collection process or in the manufacture of therapeutic plasma derivatives.
