Neutralization epitopes on HIV pseudotyped with HTLV-I: conservation of carbohydrate epitopes

HIV pseudotypes appear to be able to infect both CD4-positive and CD4-negative cells. Pseudotypes are genetically mixed viruses. Pseudotypes may occur when two viruses infect the same cell. CD4 cells are components of the immune system. An HIV-HTLV-I pseudotype was prepared. Both CD4-positive and CD4-negative cells were infected by the pseudotype. Generally, CD4-negative cells are not infected by HIV. An anti-HTLV-I serum effectively stopped infection of CD4-negative cells by the pseudotype. An anti-HIV serum did not prevent infection of CD4-negative cells. Lectins and anti-carbohydrate monoclonal antibodies prevented CD4-negative cell infection. This suggests that the infective ability of HIV may be increased in cases of coinfection with human T-cell lymphotropic virus type I (HTLV-I). Many HIV-positive patients are also infected with HTLV-I.