Table 1.
Meningococcal strains used in this study.
Fig 1.
Sequence of the modified porA promoter region used to replace the native fetA promoter.
Bases constituting the -10 and -35 regions are highlighted in green. Bases taken from the porB promoter are highlighted in blue.
Fig 2.
Verification of FetA expression in wildtype (H44/76) and genetically modified strain (SMenPF1.2).
Analysis by immunoblot (antiserum raised to recombinant FetA variant F3-3) of SDS-PAGE gel with 10 μg protein (outer membrane protein preparations) per well. BioRad pre-stained SDS broad-range standards (70kDa standard shown in Lane 1). Lane 2: Purified FetA F3-3. Lane 3: Wildtype H44/76. Lane 4: Constitutive Strain (SMenPF1.2).
Fig 3.
Characterisation by SDS-PAGE of the MenPF1 outer membrane vesicles used for immunization.
Lanes: 1) Molecular weight protein markers. 2) OMVs from strain SMenPF1.2.
Fig 4.
SDS-PAGE of outer membrane proteins from the isogenic mutant strains used to evaluate the serum bactericidal response.
50 μg total protein was loaded per lane. Lanes: 1) SMenPF1.2 (fetAp17bp), 2) 3043 (fetA::kan), 3) 3311 (fetA::kan porA::ermC), 4) 3312 (fetAp17bp porA::ermC).
Fig 5.
Immunogenicity of MenPF-1 vaccine in mice.
Total IgG titres, calculated in comparison to a pooled standard serum, were determined for sera from individual mice against bulk OMVs and the PorA and FetA antigens. The standard serum was given an arbitrary value of 10 units. The geometric mean IgG titres are indicated with a line. Error bars show the 95% confidence intervals of the mean. (A) Mice given two doses of four dose levels or an μg protein per doses. Note that the data from mice given two doses of 2.5 μg protein per dose is included in both figures for comparison, as the immunizations were performed concomitantly. Actual figures for the data presented are given in S1 Table.
Table 2.
Immunogenicity (rSBA) of MenPF-1 vaccine in mice (dose levels 1.0–10.0 μg per dose).
Table 3.
Immunogenicity (hSBA) of MenPF-1 vaccine in mice (dose levels 1.0–10.0 μg per dose).
Table 4.
Immunogenicity (rSBA) of MenPF-1 vaccine in mice (number of doses).
Table 5.
Immunogenicity (hSBA) of MenPF-1 vaccine in mice (number of doses).
Fig 6.
Immunogenicity of strain MenPF-1 in rabbits.
Total IgG titres calculated in comparison to a pooled standard serum, were determined for sera from individual rabbits against bulk OMVs and the PorA P1.7,16 and FetA F3-3 antigens. The standard serum was given an arbitrary value of 10 units. Rabbits were immunized with four doses of either adjuvant alone (Control), 25 μg total protein per doses, or 50 μg total protein per doses. Blood samples were collected from all animals (n = 12) pretrial (Sample 1), and before dosing on days 22 (Sample 2, post one dose) and 64 (Sample 3, post three doses). A fourth blood sample was taken from six rabbits on day 92 (Sample 4, post four doses). The graph shows geometric mean units. Error bars indicate the 95% confidence intervals of the mean. Actual figures for the data presented are given in S2 Table.