FIG.4.

Methyl-β-cyclodextrin differentially inhibits cholera toxin B uptake in restricted and nonrestricted cells. Permissive U87/CD4/CXCR4 or restrictive HeLa/CD4 cells were treated with MβCD. CtxB-FITC (A through F) and trf-FITC (G through J) were bound to treated or untreated cells for 1 h with or without water-soluble cholesterol and examined by confocal microscopy. Capping of CtxB-FITC at the cell surface shows inhibition. (K) MCN and MCR on HeLa/CD4 cells with or without MβCD treatment, with or without cholesterol replenishment. White bars denote no treatment, black bars denote MβCD, and grey bars denote replenishment with cholesterol.