FIG. 9.

Role of conformational anti-Fi antibodies in neutralizing activity. (A) The recombinant Fi proteins were separated by NDS-PAGE to conserve the trimeric form of the protein. The diluted serum (1/100) from patient 1 at D60 was sequentially incubated (six times) on immunoblots. Sequential exhaustion on the Fi protein was detected with HRP-labeled anti-human Ig conjugates. The percentage of the decrease in the initial signal was determined by densitometry analysis done in the linear response range of the film. (B) The neutralizing activity toward Ad in serum partially exhausted of anti-native Fi antibodies was determined with serum diluted at 1/400. Likewise, the serum from Pt-1 was sequentially exhausted on denatured Fi proteins (SDS-PAGE) and on mock proteins. The exhausted serum was used to determine the neutralizing activity. The neutralizing activities are given as percentages and are the means and standard deviations of three individual triplicate experiments.