Table 6.
SIV-specific antibody responses in plasma at the end of tenofovir treatment and after tenofovir withdrawal
| |
|
SIV-specific binding IgG1 |
Neutralizing antibody ID50 in TZM-bl cells2 |
ADCVI3 |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
% inhibition of 1:100 serum dilution | ||||||||||
| Animal number | Time point | SVA-MLV | SIVmac239CS.23 | SIVmac251-CS | SIVmac251-TCLA | SIVmac251-CS | SIVmac251-TCLA | SIVmac251 (UCD) | RT-SHIV | |
| 29276 |
Euthanasia |
409,600 |
20 |
<10 |
17 |
29,462 |
48.89 |
99.98 |
99.99 |
nd |
| 30577 |
TFV withdrawal |
409,600 |
<10 |
<10 |
12 |
380,644 |
61.77 |
99.94 |
93.49 |
99.89 |
| “ |
Euthanasia |
409,600 |
<10 |
13 |
11 |
>1,562,500 |
33.29 |
99.94 |
94.48 |
99.89 |
| 32186 |
TFV withdrawal |
1,638,400 |
<10 |
<10 |
10 |
>1,562,500 |
99.98 |
99.98 |
99.99 |
nd |
| “ |
Euthanasia |
1,638,400 |
<10 |
<10 |
<10 |
>1,562,500 |
99.98 |
99.98 |
99.06 |
nd |
| 33088 |
TFV withdrawal |
409,600 |
<10 |
<10 |
13 |
451,911 |
99.98 |
99.98 |
99.99 |
nd |
| “ |
Euthanasia |
409,600 |
<10 |
<10 |
<10 |
>1,562,500 |
99.78 |
99.98 |
99.99 |
nd |
| 33091 |
TFV withdrawal |
6,553,600 |
<10 |
<10 |
10 |
>1,562,500 |
99.98 |
99.98 |
99.99 |
nd |
| “ | Euthanasia | 6,553,600 | <10 | <10 | 12 | >1,562,500 | 99.98 | 99.98 | 99.99 | nd |
1Values of SIV-binding antibody titers are the reciprocal of the highest plasma dilution (of 4-fold dilutions) that gave a positive signal on whole-virus antibody ELISA assay specific for IgG.
2Values of neutralizing antibody are the serum dilution at which relative luminescence units (RLUs) were reduced 50% compared to virus control wells (no test sample); viruses tested were pseudoviruses SIVmac239CS.23 and SVA-MLV grown in 293 T cells, and replication-competent SIVmac251-CS (hPBMC-grown) and uncloned SIVmac251-TCLA (H9-grown; tissue culture lab adapted).
3ADCVI: antibody-dependent cell-mediated virus inhibition was tested at a 1:100 serum dilution with SIV-infected CEM.NKr R5 as targets and human PBMC as effector cells. The reported values of % inhibition are the averages of 2 independent experiments. The SIVmac251CS and SIVmac251-TCLA are the same as those used in the neutralizing antibody assay; SIVmac251 (UCD) is a stock grown in rhesus PBMC derived from the same seed stock as the SIVmac251 stock that was used to inoculate animals 32186, 33088 and 33091. The RT-SHIV stock was grown in rhesus PBMC from the same seed stock used to infect animal 30577. Only serum of RT-SHIV infected animal 30577 was tested for ADCVI activity against RT-SHIV. nd indicates not done.