Table II.
Antisera Against Plasmodium falciparum Normocyte Binding Proteins Inhibit Merozoite Invasion of Trypsinized RBCs
| PF strain | Treatment | Prebleed | NBP1 | NBP2 (S3) | NBP2a | NBP2b |
|---|---|---|---|---|---|---|
| FVO | None | 106 ± 7 | 102 ± 15 | 107 ± 25 | 114 ± 4 | 104 ± 7 |
| FVO | Trypsin | 107 ± 7 | 45 ± 2 | 65 ± 2 | 65 ± 1 | 68 ± 12 |
| HB3 | None | 94 ± 2 | 100 ± 1 | 110 ± 13 | 104 ± 17 | 95 ± 1 |
| HB3 | Trypsin | 96 ± 3 | 69 ± 17 | 45 ± 15 | 66 ± 14 | 26 ± 10 |
| MC K− | None | 118 ± 18 | 94 ± 5 | 139 ± 7 | ND | ND |
| MC K− | Trypsin | 122 ± 7 | 60 ± 12 | 43 ± 6 | ND | ND |
| 3D78 | None | 95 ± 7 | 50 ± 1 | 51 ± 3 | 57 ± 7 | 70 ± 6 |
Purified schizonts were incubated with untreated erythrocyte or trypsin-treated erthrocytes (T) in the presence of purified IgG. IgG was added at 1 mg/ml and invasion rates are expressed as a percentage of invasion in the absence of any IgG, with standard error.