Table 2.

Comparison of OMP26-specific antibodies in serum and BAL following immunization with either OMP26 or killed bacteria fromH. influenzae strains

GroupbnELISA titera of antibody to OMP26a
SerumBAL
IgGIgAIgMIgGIgAIgM
Nonimmune7NDd ND10.5 ± 1.6NDNDND
Immunized
 OMP26
  10 μg51,209 ± 255e 936 ± 161e 30.5 ± 4e 4.3 ± 1.0e 6.1 ± 1.9e ND
  40 μg52,806 ± 405e 2,440 ± 410e 142.5 ± 30.6e 8.3 ± 1.9e 29.1 ± 7.9e ND
 Killed bacteriac
  NTHI-Ic 458 ± 17e 37 ± 4e 39.1 ± 0.8e 0.5 ± 0.11.2 ± 0.5ND
  NTHI-IIc 422 ± 4e 26 ± 5e 39.3 ± 5.0e 0.6 ± 0.10.4 ± 0.1ND
  HI-CDc 418 ± 1e 20 ± 1e 42.2 ± 3.1e 0.6 ± 0.10.8 ± 0.3ND
  Hib-IIc 427 ± 4e 38 ± 3e 34.4 ± 2.3e 0.6 ± 0.11.6 ± 0.4ND
  • a Calculated as described in Materials and Methods.

  • b Rats were immunized via IPP on day 0, received an i.t. boost on day 14, and were challenged with live bacteria on day 21. Serum and BAL samples were prepared as described in Materials and Methods.

  • c Rats were immunized with killed bacteria from the strain of H. influenzae indicated and had received a live challenge with bacteria from the homologous strain.

  • d ND, OMP26-specific antibody could not be detected at the lowest sample dilution.

  • e P < 0.05 compared to nonimmune group.