TABLE 2.
Infectious virus levels in blood and lymphoid tissues at time of euthanasia or death, and CD4+/CD8+ T-cell ratio in thymus cells
| Animal group and numbers | Period of PMPA treatmenta | Time of euthanasiab | TCID50c
|
CD4+/CD8+ thymus cellsd | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| PBMC | Plasma | Spleen | Mes. LN | Ing. LN | Ax. LN | Thymus | ||||
| A | ||||||||||
| 30013 | None | 12 wks | 1,000 | 1,000 | 2,153 | 464 | 4,640 | 215 | 1,778 | 0.60 |
| 30015 | 13 wks | 316 | 1,000 | 2,153 | 2,153 | 1,000 | 100 | 316 | 0.36 | |
| 30073 | 11 wks | 464 | 3,160 | 3,160 | 3,160 | 3,160 | 32 | 316 | 0.38 | |
| 30079 | 15 wks | 32 | 316 | 100 | 316 | 32 | 22 | 316 | 0.51 | |
| B | ||||||||||
| 30020 | Days 5–19 | 24 wks | 100 | 1,000 | 100 | 1,000 | 46 | 316 | 3 | 5.96 |
| 30022 | 24 wks | 3,160 | 100,000 | 10,000 | 10,000 | 178 | 3,160 | ≤3 | 0.85 | |
| 30023 | 24 wks | ≤1 | ≤3 | 100 | 3 | ≤1 | 5 | ≤0.3 | 9.69 | |
| 30024 | 24 wks | 22 | ≤3 | 100 | 100 | 316 | 32 | 22 | 1.09 | |
| C-I | ||||||||||
| 30053 | Days 5–65 | 24 wks | 316 | 215 | 3,160 | 10,000 | 2,153 | 10,000 | ≤1 | 1.82 |
| 30054 | 24 wks | 10 | <3 | 588 | 178 | 46 | 178 | ≤3 | 1.08 | |
| 30055 | 24 wks | 10 | ≤3 | 46 | 100 | 100 | 100 | ≤0.3 | 1.79 | |
| 30061 | 24 wks | 316 | 59 | 3,160 | 1,778 | 215 | 588 | ≤3 | 1.79 | |
| C-II | ||||||||||
| 30074 | Days 5–65 | 65 days | 5 | ≤3 | 46 | 5 | 3 | ≤3 | ≤0.1 | 2.11 |
| 30077e | 65 days | ≤0.1 | ≤3 | ≤0.1 | ≤0.1 | ≤0.1 | ≤0.1 | ≤0.1 | 2.44 | |
Within 3 days of birth, all animals were inoculated orally with SIVmac251; groups B and C were started on PMPA treatment at 5 days of age for 14 days (group B) or 60 days (group C).
Animals of group A were euthanized at time of clinical immunodeficiency (simian AIDS), while animals of groups B and C were euthanized prior to development of simian AIDS, either at the end of PMPA treatment (group C-II) or at 24 weeks of age (group B and C-I).
Cell-associated and cell-free virus levels in peripheral blood and fresh lymphoid tissues collected at time of euthanasia were determined by limiting dilution culture of single-cell suspensions or plasma and are expressed as the numbers of TCID50s per 106 mononuclear cells or per milliliter of plasma. When no virus could be detected, the detection limit is given, based on the number of mononuclear cells or the amount of plasma available for virus isolation. Abbreviations: Mes. LN, Ing. LN and Ax. LN indicate mesenteric, inguineal and axillary lymph node, respectively.
Ratio of CD4+CD3+ over CD8+CD3+ thymus cells was determined by flow cytometry.
Virus could not be isolated from animal 30077 from 0.5 ml of plasma or from 107 cells of each lymphoid tissue at time of euthanasia.