HLA class II antigens and the HIV envelope glycoprotein gp 120 bind to the same face of CD4. (human lymphocyte antigens) (Periodical Report) (Abstract) (Abstract)

According to the authors' abstract of an article published in the Journal of Immunology, "Although the HIV gp120 binding site of CD4 is well characterized, its interaction site with HLA class II molecules is still controversial. Sixty-seven mutations within the four extracellular domains of CD4 were examined for their effects on cell surface expression and conformational changes and for adhesion of HLA class II-expressing B lymphocytes and HIV gp120 binding to CD4-transfected COS cells. Mutations within the gp120 binding site affected both assays similarly, indicating that the two sites fully overlap. A few additional substitutions of residues mapping on the same face …