Immunofluorescence detection of CCR5 using confocal microscopy.

(A-D) Effects of inhibitors on CCR5 internalization in CHO.CCR5 cells. (A) Untreated cells, stained with anti-CCR5 antibody. (B) Cells treated with MIP-1α. (C) Cells pretreated with sucrose. (D) Cells pretreated with nystatin; cells were grown on coverslips for 24 hours and then treated with inhibitors and chemokine as described in “Materials and methods.” Similar results were obtained for filipin or in CHO.CCR5.CD4 cells (data not shown). (E-H) Effects of CCR5 activation on arrestin-2 movement in CHO.CCR5 cells. (E) Untreated cells transfected with pEGFP–arrestin-2. (F-H) Cells treated with MIP-1α as described and then stained with anti-CCR5 antibody and rhodamine-conjugated secondary antibody. (F) CCR5 (red). (G) pEGFP–arrestin-2 (green). (H) Overlay arrestin-2 and CCR5.