FIG. 4.

Effect of anti-BAD1 antibodies on complement activation and C3 binding to B. dermatitidis yeast cells (26199). (A) Kinetics of C3 deposition were assessed in complement-binding medium containing either pooled NHS (●) or yeast-absorbed NHS that was supplemented, per milliliter of medium, with anti-BAD1 MAb DD5-CB4 at 0 μg (○), 1.6 μg (▴), 6.3 μg (▪), 25 μg (♦), or 100 μg (▾). (B) Capacity of C3 binding to strain 26199 yeast cells was determined following a 30-min incubation in nonimmune NHS or in sera from three blastomycosis patients. Anti-BAD1 endpoint titers for the patient sera were as follows: 7758, 1:10,240; 7740A, 1:5,000; 8637, 1:2,000. Data representative of duplicate experiments are shown.