Fig. 4. Functional effects of MIIA targeting. (A) Increase in the migratory response of J77 cells transfected with MIIA tail-GFP to 100 nM SDF-1. Data represent the percentages of migrated cells in response to SDF-1, normalized with respect to untransfected (Ut) cells treated with SDF-1 (mean ± s.e.m.) of three independent experiments ^*P<0.05. (B) Increase in the migratory response of J77 cells transfected with siRNA oligonucleotides for MIIA (MIIA1 and MIIA2) to 100 nM SDF-1. Data represented are the percentages of migrated cells in response to SDF-1, normalized with respect to cells with no SDF-1-treatment (mean ± s.d.) of three independent experiments ^*P<0.05. (C) Loss of the anti-HIV-1 fusogenic capacity of SDF-1 in cells transfected with MIIA tail-GFP, in Env-HIV-mediated cell fusion experiments, by using MIIA tail-GFP-transfected HeLa cells, at non-saturating concentrations of the chemokine. The level of cell fusion was evaluated by quantitative measurement of chemiluminescence, using a kit that couples -galactosidase and luciferase activity (-gal reporter gene assay); results are shown as the mean ± s.e.m. of three independent experiments ^*P<0.05. (D) Series of images of a representative experiment of those quantified in C, showing the block of Env-mediated cell-to-cell fusion by SDF-1 at different concentrations by using a fusion model, based on HeLa cells transfected with MIIA tail-GFP. The number and size of syncytia formed were monitored by X-Gal staining. Images were acquired with a 10x objective.