Figure 6

Effect of ASC-CM on latency-reactivation efficacy of panobinostat. (A) Effect of exposure to ASC-CM (25% or 50%) or HDACi [SAHA or Panobinostat(Pano)] on HIV-1 Nef protein expression (top panels) and HIV-1 p24 production (bottom panels) by the U1 cells. Relative Western blot band intensity (presented the numbers to the corresponding lanes on the top panel) was compared by the Image-J software (version 1.50). The ASC-CM mediated latency reactivation was much more potent, as compared to SAHA (300 nM) or panobinostat (10 nM). (B) Effect of ASC-CM (25%) coexposure on panobinostat (2.5–10 nM) mediated increases in HIV-1 p24 production by U1 cells. Coexposure to ASC-CM increased the latency-reactivation efficacy of panobinostat. (C) Effect of increasing concentrations of ASC-CM (10–50%) on panobinostat (10 nM) induced latency-reactivation. Coexposure to even low concentrations of ASC-CM increased latency-reactivation by panobinostat. (D) Effect of CM, from either non-migratory or migratory ASCs (nmASCs and mASCs, respectively) on latency-reactivation by panobinostat (10 nM). The mASCs retain their ability to activate HIV-1 p24 from U1 cells and secrete factors that augment the efficacy of panobinostat. Error bars show ± SEM and significant changes are represented as P-values (*p < 0.01, **p < 0.001, ***p < 0.0001). Coexposure to ASC-secreted factors potentiate the efficacy of a clinically approved HDACi, i.e. panobinostat (Pano).