Figure 2.

Localization of BPI to the cell surface. (A) BPI was localized by confocal microscopy in nonpermeabilized Caco2 cells exposed to vehicle (Top) or ATLa (1 μM, 24 h, Middle and Bottom). BPI adsorbed antisera was used as a control (Bottom). Shown here are confocal sections through the mid-zone, subjunctional portion of epithelial monolayers. Representative experiment from n = 2. (B) T84 cells were preexposed to ATLa (1 μM) for indicated periods of time. Cell surface proteins were nonspecifically labeled with biotin, BPI was immunoprecipitated from cell lysates, resolved by SDS/PAGE, and Western blots were probed with avidin peroxidase. Also shown is the immunoprecipitation control (omission of primary Ab) as well as a biotinylated BPI standard. Representative experiment from n = 3.