TABLE 1.
Ability of rVV expressing different levels of murine cytokines to protect mice against RSV challenge 3 weeks after vaccination
| Vaccine | Gene inserted at the following
VV genome locus:
|
Titer of F proteina | Cytokine expression
(ng)b
|
Antibody response to RSVc | Lung RSV titerd | BAL cell counte | ||
|---|---|---|---|---|---|---|---|---|
| TK | VP37 | S/N | C/A | |||||
| VSCF | F | 759 | ND | ND | 5.2 ± 0.3 | <1.7h | 5.8 ± 0.2i | |
| VRBF | F | 1,995 | ND | ND | 5.1 ± 0.4 | <1.7h | ND | |
| VRBmIL-2 | IL-2 | ND | 3,470 | 210 | <1.5 | 4.4 ± 0.3 | ND | |
| VRBF.mIL-2low | IL-2 | F | 1,738 | 5 | 1 | 4.5 ± 0.1g | <1.7h | ND |
| VSCF.mIL-2high | F | IL-2 | 708 | 3,400 | 310 | 4.1 ± 0.1f | <1.7h | 5.8 ± 0.1i |
| VRBmIL-4 | IL-4 | ND | 8,650 | 840 | <1.5 | ND | ND | |
| VRBF.mIL-4low | IL-4 | F | 2,884 | 7 | 1 | 5.1 ± 0.2 | <1.7h | ND |
| VSCF.mIL-4high | F | IL-4 | 776 | 6,700 | 490 | 5.0 ± 0.2 | <1.7h | 5.7 ± 0.1i |
| VRBmIFN-γ | IFN-γ | ND | 3,430 | 315 | <1.5 | 4.2 ± 0.2 | ND | |
| VRBF.mIFN-γlow | IFN-γ | F | 1,548 | BD | BD | 4.5 ± 0.2g | <1.7h | ND |
| VSCF.mIFN-γhigh | F | IFN-γ | 794 | 3,630 | 300 | 3.0 ± 0.2f | <1.7h | 5.6 ± 0.1i |
| VA-βgal | βgal | ND | ND | ND | <1.5 | 4.3 ± 0.2 | 5.2 ± 0.1 | |
Means (n = 3) of titers of F glycoprotein determined by an ELISA. ND, not determined.
Total cytokine levels in 60-mm-diameter petri dish. BD, below detection. S/N, supernatant; C/A, cell associated.
Mean ± SD log10 titer of antibody to RSV determined by an ELISA 3 weeks postvaccination.
Mean ± SD log10 PFU of RSV per gram recovered from lungs of mice 5 days after RSV challenge.
Mean ± SD log10 cells per milliliter 5 days after RSV challenge.
The probabilities of the differences in antibody responses between VSCF-vaccinated mice and VSCF.mIL-2- or VSCF.mIFN-γ-vaccinated mice were <0.02 and <0.0001, respectively, as calculated by Student’s t test.
Antibody responses between VRBF-vaccinated mice and VRBF.mIL-2- or VRBF.mIFN-γ-vaccinated mice were significantly different, as determined by Student’s t test (P < 0.02 and P < 0.06, respectively).
Virus titers between vaccinated and control mice were significantly different, as determined by Student’s t test (P < 0.0001).
BAL cell counts in vaccinated mice were significantly different from those in VA-βgal-treated control mice, as determined by Student’s t test (P < 0.006).