Abstract: This invention comprises animal derived cells, especially erythrocytes, which have been artificially modified (and referred to as engineered erythrocytes or RBCs) so as to incorporate in their plasma membranes an antigen, CD4 protein derived from lymphocytes) which will cause them to selectively seek out and fuse with other cells that are infected with a virus, especially the AIDS virus. These modified cells can be further altered so as to contain in their cytoplasm a cytotoxic agent which, after the cell has fused with a target cell, will result in the pooling of their respective cytoplasms and the death of both cells. Such modified cells can be used as a basis for an in vitro diagnostic assay involving cells derived from the blood of patients suspected of having AIDS.

Abstract: A method of incorporating human CD4 or glycophorin into a red blood cell membrane is provided comprising exposing the red blood cell to an electric field while the cell is suspended in an electro-insertion medium in the presence of a buffered solution (suspension) of the proteins. These proteins bear a hydrophobic membrane spanning sequence. The resultant cell of the electro-insertion is then contacted with a resealing medium.