HIV-1-infected HCs have the capacity to infect CBMCs and PBMCs. In order to determine the infectivity of HCs, HIV-1BaL infected HCs and MDMs were co-cultivated separately with (A) CBMCs and (B) PBMCs. After 6 h, the CBMCs and PBMCs were cultured separately, and HIV-1 replication was measured in the cell supernatants by HIV-1 p24 viral antigen ELISA. Closed squares represent HC-infected cells and open squares indicate MDM-infected cells. Data shown are expressed as the mean ± SE of triplicate samples and are representative of 3 independent experiments from different donors (**p < 0.01; ***p < 0.001).