TABLE 1.
Density/immunogenicity relationships of conjugates prepared with 10- and 15-mers of γDPGA bound to TT or rPAa
| Conjugate | γDPGA (mol)/ protein (mol) | Protein/γDPGA (wt/wt) | Anti-γDPGA (EU)
|
Anti-rPA (μg/ml)
|
||
|---|---|---|---|---|---|---|
| 2nd injection | 3rd injection | 2nd injection | 3rd injection | |||
| TT/Cys-Gly3-γDPGA10 | 11 | 1:0.10 | 420 | 7,800 | NTb | NT |
| TT/Cys-γDPGA10 | 16 | 1:0.16 | 6,900 | 6,700 | NT | NT |
| TT/Cys-γDPGA15 | 16 | 1:0.22 | 6,500 | 7,700 | NT | NT |
| TT-CHO/AH-γDPGA15 | 37 | 1:0.48 | 1,900 | 2,300 | NT | NT |
| rPA-CHO/AH-γDPGA15 | 5 | 1:0.12 | 120 | 320 | 0.2 | 4 |
| rPA-CHO/AH-γDPGA15 | 11 | 1:0.26 | 3,600 | 5,200 | 0.1 | 13 |
| rPA-CHO/AH-Gly3-γDPGA10 | 29 | 1:0.45 | 210 | 1,300 | 0.1 | 2 |
| rPA-AH/CHO-Gly3-γDPGA10 | 22 | 1:0.34 | 1,000 | 2,500 | 0.3 | 28 |
| rPA/Cys-Gly3-γDPGA10 | 15 | 1:0.24 | 2,100 | 4,000 | 37 | 170 |
| rPA-ITL/Br-Gly3-γDPGA10 | 8 | 1:0.13 | 2,300 | 3,700 | 4.7 | 61 |
| rPA-ITL/Br-Gly3-γDPGA10 | 18 | 1:0.29 | 2,400 | 3,000 | 0.2 | 41 |
a
Five- to 6-week-old NIH general-purpose mice (n = 10) were injected subcutaneously with 2.5 μg of γDPGA as a conjugate 2 weeks apart and exsanguinated 7 days after the second or third injection. IgG anti-γDPGA and anti-rPA were measured by ELISA, and the results are expressed as the geometric means.
b
NT, not tested.