FIG. 4.

Phage-mediated depletion of Pb epitope-specific antibodies. Phages carrying the Pb epitopes indicated at the top of each panel were amplified and incubated with D10 serum samples from patients 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, and 16, as well as samples 18, 19, 20, and 21 from healthy donors. After removal of the phage-antibody complexes by centrifugation, the serum supernatants were assayed for their effect on Ad-mediated gene transfer by using the replication-competent Ad5Luc3 vector. Luciferase expression was compared in cells infected with Ad5Luc3 treated with depleted or nondepleted sera. Theoretically, values greater than 1.0 for the ratio of luciferase levels between depleted and nondepleted serum samples indicated a decrease in NA activity after phage depletion but, once the experimental errors are taken into account, only values of >1.3 were considered significant.