TABLE 4.
Formulation/immunogenicity relationships of conjugates prepared with a 10-mer of γDPGA bound to rPA or TTa
| Conjugate | γDPGA (mol)/rPA (mol) | Dose (μg/mouse)b | Anti-γDPGA (EU)
|
Anti-protein (μg/ml)
|
||
|---|---|---|---|---|---|---|
| 2nd injection | 3rd injection | 2nd injection | 3rd injection | |||
| rPA/Cys-Gly3-γDPGA10 | 22 | 2.5 | 2,200 | 5,800 | 2 | 210 |
| 2.5 + al | 3,500 | 6,200 | 80 | 280 | ||
| rPA/Cys-Gly3-γDPGA10 | 13 | 1 | NTc | 2,900 | NT | 61 |
| 1 + form | NT | 2,600 | NT | 23 | ||
| 1 + al | NT | 4,000 | NT | 260 | ||
| 1 + al & form | NT | 3,300 | NT | 300 | ||
| rPA-ITL/Br-Gly3-γDPGA10 | 18 | 2.5 | 2,400 | 3,000 | 0.2 | 41 |
| 2.5 + al | 5,600 | 5,400 | 250 | 680 | ||
| TT/Cys-γDPGA10 | 16 | 2.5 | 6,900 | 6,700 | NT | NT |
| 2.5 + al | 8,310 | NT | NT | NT | ||
| TT/Cys-γDPGA15 | 16 | 2.5 | 6,500 | 7,700 | NT | NT |
| 2.5 + al | 7,800 | 15,000 | NT | NT | ||
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
al, aluminium hydroxide (Alhydrogel); form, formaldehyde treatment according to the methods of Porro et al. (19a) and Nencioni et al. (17a).
c
NT, not tested.