QUANTIFICATION OF CELL-ASSOCIATED AND FREE ANTIGENS IN BORDETELLA-PERTUSSIS SUSPENSIONS BY ANTIGEN-BINDING ELISA

In order to achieve batch-to-batch consistency of whole-cell pertussis vaccines, properties relevant for protection and safety should be cha racterised. Therefore, ELISAs to quantify pertussis toxin (PT), filame ntous haemagglutinin (FHA), 92 kD outer membrane protein (92 kD-OMP) a nd pertactin (PRN) in Bordetella pertussis (B. pertussis) suspensions were developed. In this paper the influence of the bacterial growth st age on antigen production and antigen release into the supernatant was studied for pertussis strains 134, 509 and CS. The levels of cell-ass ociated and free antigens during growth were strongly strain and antig en dependent. Because of this, the proportion of cell-associated antig ens changed during cultivation for all three strains. Substantial amou nts of PT and PRN were released into the supernatant, while little fre e FHA and 92 kD-OMP were found. The amount of cell-associated FHA decl ined rapidly during growth, whereas cell-associated 92 kD-OMP contents increased. These findings demonstrate that, although antigen exposure and release differ from strain to strain, the main factor that determ ines the antigen production and release is the growth phase.