FIG. 7.

FIX promotes efficient binding of Ad31 to and infection of intestinal cells, independently of cell surface heparan sulfate. (A) Ad31 virions were preincubated with coagulation factors, with or without EDTA as indicated, and allowed to infect adherent intestinal FHs74Int cells for forty-four hours. Infected cells were stained and quantified as described in Materials and Methods. (B to D) ³⁵S-labeled, CsCl-purified Ad31 virions were preincubated with increasing concentrations of FIX (B) or with/without fixed (physiological) concentrations of FIX and increasing concentrations of heparin (C), or with/without fixed concentrations of FIX, and then mixed with cells pretreated with increasing concentrations of heparinase I (D) for one hour on ice. Unbound virions were washed, and cell-associated radioactivity was measured in a scintillation counter. Values are means ± SD. *, P of <0.05 versus control; **, P of <0.01 versus control. Bars in panel A indicate comparisons between FIX and FIX-EDTA or between FX and FX-EDTA.