CD4 and HIV-1 infection: This observation, combined with the high incidence of HIV-2 infection in Europe and a small number of studies compared to HIV-1 infection, led us to select four primary HIV-2 isolates to evaluate the efficiency of transmission from Mø, imDCs, and mDCs to CD4+ T lymphocytes, using the HIV-1Ba-L strain (UCFL1034) as a control.