TABLE 4.
Effect of CX4C mutation on antibody responses 75 days p.i.a
| Group | Neutralization titer | IgG (total RSV) | IgG (G peptide) (aa 155–206) | IgG2a (total RSV) | IgG1 (total RSV) | IgG1/IgG2a |
|---|---|---|---|---|---|---|
| Wt A2 | 63 ± 11 | 10,708 ± 1,980 | 834 ± 54 | 3,384 ± 412 | 3,387 ± 401 | 1.02 ± 0.2 |
| A2 CX4C | 110 ± 19b | 14,284 ± 1712b | 1,575 ± 34b | 7,009 ± 1102b | 1,688 ± 581b | 0.25 ± 0.1 |
| Wt r19F | 128 ± 11 | 10,428 ± 4,075 | 1,723 ± 28 | 3,304 ± 721 | 3,145 ± 792 | 1.20 ± 0.5 |
| r19F CX4C | 188 ± 25b | 16,740 ± 2691b | 3,436 ± 21b | 9,511 ± 1265b | 782 ± 176b | 0.09 ± 0.03 |
| Mock | NA | NA | NA | NA | NA | NA |
BALB/c mice were treated or not with MAb F(ab′)2 131-2G 2 days before challenge with 106 TCID50 of wild-type A2 and r19F-CX3C and 2 × 106 TCID50 of A2 and r19F-CX4C or mock-infected tissue culture material (Mock). RSV- and RSV G peptide (aa 155 to 206)-specific antibody IgG and RSV-specific isotype IgG2a and IgG1 were measured by ELISA against RSV tissue culture lysate, as described in Materials and Methods. Data are titers calculated by dilution factors and end point calculations. The results are presented as averages of data from two separate experiments ± SEM from 5 mice per group. NA, not applicable.
P < 0.05, a significant difference as determined by one-way ANOVA and post hoc Tukey's HSD test, compared to A2 and r19F-CX3C with CX4C-mutated A2 and r19F.