TRANSFERRIN-BINDING PROTEINS ISOLATED FROM NEISSERIA-MENINGITIDIS ELICIT PROTECTIVE AND BACTERICIDAL ANTIBODIES IN LABORATORY-ANIMALS

Transferrin-binding proteins (Tbps) were affinity-isolated from group B Neisseria meningitidis strain B16B6 and used to raise specific antis era. Administration of the antisera to mice loaded with human transfer rin before bacterial challenge significantly protected the animals fro m death. In active immunization studies, mice received three 25 mug in jections of purified Tbps over a period of 28 days, 7 days after which they were challenged with N. meningitidis. The survival rate in immun ized mice was much higher than in control groups. In both active and p assive immunization experiments mice were protected against at least 1 00 LD50. A specific Tbp antiserum was highly bactericidal against the parent strain and against approximately half of the strains tested.