A conservative domain shared by HIV gp120 and EIAV gp90: implications for HIV vaccine design.

Both HIV and EIAV belong to the retroviridae family and lentivirus genus. Two variable regions (V3 and V4) of equine infectious anemia virus (EIAV) gp90 and two variable regions (V1 and V2) of HIV gp120 possibly adopt the same topology. We have studied the N-glycosylation properties and B cell linear epitope distribution profile of these two regions. Our results indicated that V3 and V4 of EIAV gp90 are very similar to V1 and V2 of HIV gp120. The differences between EIAV virulent and vaccine strains are mainly located at these two regions. Vaccine strains lose two N-glycosylation sites at these two regions. Because of the conservative domain shared by EIAV gp90 and HIV gp120, V1 and V2 of HIV gp120 and their glycosylation properties should be the regions preferably considered for HIV vaccine design.