FIG. 4.
Replication of MV in HIV-1-infected PBMCs and requirement for live MV. Chicago-1 or Edmonston MV was added to CCR5-tropic HIV-1BaL-infected PBMCs (A) or CXCR4-tropic HIV-1IIIB-infected PBMCs (B) at a MOI of 15 or 1.5 to 0.00015. Production of MV was measured after 96 h of coculture by plaque formation on Vero cells. Data are presented as means ± standard errors of the means (SEM) (error bars) of duplicate wells with PBMCs from two to six donors. Values that are significantly different (P < 0.05) between Chicago-1 and Edmonston strains of MV are indicated by an asterisk. ND, not done. (C and D) Time course of MV production by HIV-1-infected PBMCs. PBMCs were infected with HIV-1 CCR5-tropic HIV-1BaL (C) or CXCR4-tropic HIV-1IIIB (D), and Chicago-1 or Edmonston MV was added on day 2 of cells in culture at a MOI of 0.15. Data are presented as means ± SEM (error bars) of duplicate wells with PBMCs from three to seven donors. Values that are significantly different (P < 0.05) between Chicago-1 and Edmonston strains of MV are indicated by an asterisk. MV and Vero cell lysates were UV irradiated for 2 min and added to HIV-1BaL-infected PBMCs (E) or HIV-1IIIB-infected PBMCs (F) and tested at 96 h. p24 antigen (Ag) production was determined by EIA. Values that are significantly different (P < 0.05) between Chicago-1 and Edmonston MV strains are indicated by an asterisk and bracket. Data are presented as means ± SEM (error bars) of duplicate wells with PBMCs from 10 donors. Values that are significantly different (P < 0.05) between live or inactivated MV and Vero cell lysate are indicated by an asterisk.