TABLE 2.
Isotype analysis following vaccination with recombinant PA domain proteins
| Strain | Titera
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Anti-PA1-4
|
Anti-PA1
|
|||||||||
| IgG1 | IgG2a | IgG2b | IgM | IgA | IgG1 | IgG2a | IgG2b | IgM | IgA | |
| A/J | 200 | 25 | 25 | 25 | 25 | 200 | 50 | 50 | 25 | 25 |
| BALB/c | 32,000 | 25 | 25 | 50 | 25 | 19,200 | 1,800 | 1,000 | 25 | 25 |
| C57BL/6 | 3,200 | 25 | 25 | 25 | 25 | 3,200 | 25 | 1,600 | 25 | 400 |
| Swiss Webster | 1,600 | 25 | 25 | 25 | 25 | 2,000 | 300 | 75 | 50 | 25 |
a
The IgG, IgM, and IgA isotype titers of sera collected 2 weeks after two immunizations were determined by ELISA. The results represent those for a pool of sera derived from five mice per treatment group. The endpoint was defined as the highest serum dilution that consistently showed a twofold increase in absorbance over that obtained with the preimmune serum sample (i.e., the value of 25 was equal to the background). The reactive titers were expressed as the reciprocal endpoint dilution. Anti-PA1-4, mice immunized with PAD1-4; Anti-PA1, mice immunized with PA1.