Glycosylphosphatidylinositol-anchored CD4/Thy-1 chimeric molecules serve as human immunodeficiency virus receptors in human, but not mouse, cells and are modulated by gangliosides.

Human and mouse cell lines that expressed a CD4/Thy-1 fusion protein on the cell surface were constructed and tested for the capacity to be infected with human immunodeficiency virus. The human cell lines, in contrast to the mouse line, were infectable. The CD4/Thy-1 fusion, which is anchored to the membrane by a glycosylphosphatidylinositol tail rather than a peptide linkage, can therefore serve as a human immunodeficiency virus receptor. In addition, this molecule, like CD4, is down-modulated in its cell surface expression by exogenous gangliosides.