Recombinant CCR5-T4L down-regulates surface CCR5 expression in MDMs, and inhibits MDM migration and binding properties.

<p>A and B) Effect of soluble recombinant CCR5-T4L or CCL5 on surface CCR5 expression in MDMs. MDMs were treated with soluble recombinant CCR5-T4L (1 μg/ml), CCL5 (1 μg/ml), or PBS for 24 h at 37°C. Surface (A) and intracellular CCR5 (B) were analyzed using flow cytometry and the PE-conjugated monoclonal antibody (2D7). Recombinant CCL5 protein was used as a control. The cellular distribution of CCR5 receptors was analyzed by fixing and permeabilizing cells using BD Cytofix/Cytoperm buffer. Data shown are from one representative experiment that was independently repeated at least three times. C) Dose-dependent effects of CCR5-T4L or CCL5 on surface CCR5 expression in MDM. D and E) Dose-dependent effects on MDM migration by CCR5-T4L (D) or CCL5 (100 nM) plus different concentrations of CCR5-T4L protein (E). F and G) Dose-dependent effects on [125I]-CCR5 binding by CCR5-T4L (F) or CCL5 (100 nM) plus different concentrations of CCR5-T4L protein (G). H and I) Dose-dependent effects on CCL5-induced [³⁵S]GTPγS binding to membranes from human macrophages cells treated with CCR5-T4L (H) or CCL5 (100 nM) plus different concentrations of CCR5-T4L protein (I). Data are the mean ± SD of triplicate cultures, which are representative of three experiments.