FIG 4.

Dose-dependent inhibition of HIV expression in human macrophages following MGBG treatment. In vitro differentiated human macrophages were infected with EGFP-tagged HIV for 6 h and cultured for another week. MGBG was either present continuously (the “complete treatment” mode) or only during the 6-h acute infection period (the “cotreatment” mode). EGFP expression in the cells was determined by FACS, and the p24 antigen in the culture supernatant was quantified by ELISA. Due to individual variations, the data were normalized against an HIV-infected, nontreated sample in each experiment. The graphs show the means and SEMs of the normalized results from multiple donors. Noninfected cells were included as a negative control for assay specificity. A 20 nM concentration of elvitegravir (EVG) was included in these experiments as a positive control. The results for the complete treatment mode were from 5 donors, and those for the cotreatment mode were from 3 donors. The average percentage of HIV-infected, untreated EGFP cells was around 5%, and the average HIV p24 concentration of HIV-infected, untreated cells was about 10 ng/ml. A statistically significant linear trend in the association between MGBG dose and effect on p24 was observed for both complete (P = 0.008) and cotreatment (P = 0.02) modes. However, the association for EGFP was attenuated after Greenhouse-Geiser correction for sphericity. Detailed FACS data for EGFP expression are shown in Fig. S2 and S3 in the supplemental material.