TABLE 3.
Antibody-mediated neutralization of primary SIVmac251 in CEMx174 cells and human and rhesus PBMC
| Virus and macaque no.a | Neutralization titer for SIVmac251
|
|||
|---|---|---|---|---|
| Laboratory adapted, in CEMx174 cellkilling assayb | Primary, in p27 reduction assayc in:
|
|||
| CEMx174 cells | Human PBMC | Rhesus PBMC | ||
| SIVmac239Δnef | ||||
| H313 | 1:5,239 | 1:10 | <1:5 | <1:5 |
| H323 | 1:5,205 | 1:80 | ≥1:5 | <1:5 |
| H324 | 1:30,319 | 1:50 | <1:5 | <1:5 |
| H343 | 1:11,551 | 1:10 | <1:5 | <1:5 |
| H345 | 1:11,729 | 1:80 | <1:5 | <1:5 |
| H348 | 1:28,883 | 1:20 | ≥1:5 | <1:5 |
| SIVmac239Δ3 | ||||
| 17155 | 1:13,894 | 1:20 | <1:5 | <1:5 |
| 17158 | 1:11,295 | 1:5 | <1:5 | <1:5 |
| 17159 | 1:1,479 | <1:5 | <1:5 | <1:5 |
| 63-88 | 1:2,539 | 1:20 | <1:5 | <1:5 |
| 99-88 | 1:11,764 | 1:10 | <1:5 | <1:5 |
| 120-87 | 1:3,722 | <1:5 | <1:5 | <1:5 |
| SIVmac251 | ||||
| 145-86 | 1:5,850 | 1:50 | <1:5 | <1:5 |
| 244-86 | 1:3,813 | 1:20 | 1:20 | NT |
| 354-95 | 1:13,917 | <1:5 | 1:5 | NT |
| 578-91 | 1:4,025 | <1:5 | <1:5 | NT |
| 579-91 | 1:4,853 | 1:5 | <1:5 | NT |
Macaques were infected with either SIVmac239Δ3 or SIVmac239Δnef for 1.5 and 3.2 years, respectively. Macaques 145-86 and 244-86 had been infected with SIVmac251 for approximately 4 years and remained healthy. The remaining macaques had been infected with SIVmac251 for 2 months (354-95) and 6 months (578-91 and 579-91).
Neutralization titers are the serum dilutions at which 50% of CEMx174 cells were protected from virus-induced cell killing. Laboratory-adapted SIVmac251 was grown in H9 cells.
Viruses were grown in rhesus PBMC and assayed in CEMx174 cells, human PBMC, and rhesus PBMC as described in the text for the p27 reduction assay for which results are shown in Fig. 1. The same volume of virus was used for all assays. Due to differences in infectivity in the different cell types, the 50% tissue culture infectious doses used were 10,000, 1,600, and 800 for CEMx174 cells, human PBMC, and rhesus PBMC, respectively. Neutralization titers are the plasma dilutions at which p27 production was reduced >80% relative to that in serum from an SIV-naïve macaque. Plasma samples were assessed in human and rhesus PBMC at a 1:5 dilution only. Primary SIVmac251 was grown in rhesus PBMC and was a single passage of the animal challenge stock. NT, not tested.