Enhanced HIV infectivity and changes in GP120 conformation associated with viral incorporation of human leucocyte antigen class I molecules

Abstract

The infectivity of primary HIV-1 X4 isolates and of TCLA viruses is increased upon viral incorporation of HLA Cw4 molecules. This effect is associated with changes in viral envelope proteins conformation including an enhanced expression of the V3 loop of gp120, and of epitopes that are exposed upon CD4 binding. The gp120 conformational changes are consistent with the formation of a multimolecular complex between HLA class I and gp120/160. HLA Cw4 incorporation is also associated to a lower susceptibility to antibody neutralization. These findings have important implications for understanding the immune response to cryptic and conformational epitopes of the viral envelope.