FIG. 8.

Role of anti-Pb antibodies in neutralizing activity. (A) The recombinant Pb proteins were separated by SDS-PAGE. The immunoblot was sequentially incubated with serum (Pt-1, day 60) diluted 1/100. Sequential exhaustion on the Pb protein was detected with HRP-labeled anti-human Ig conjugate. The percentage of anti-Pb antibodies exhausted from the serum was determined after quantification by the Image Quant program. Densitometry analysis was done in the linear response range of the film. After the final exhaustion (E6), we detected only 29% of the initial signal. (B) The partially exhausted serum (1/400) was tested for its capacity to neutralize the viral particle. The same serum was sequentially exhausted on mock proteins (six times) and was tested in the same way for the presence of anti-Ad neutralizing antibodies. The neutralizing activities are given as percentages and are the means and standard deviations of three individual triplicate experiments.