Summary of the Developmental Features of Pre- and Post-β-Selected Human Pre-T Cells
| . | Thymocyte Population . | ||||
|---|---|---|---|---|---|
| CD4+CD8− CD3− . | CD4+CD8αα+ CD3− . | CD4+CD8αβ+ CD3lowpTα+ . | CD4+CD8αβ+ CD3− large . | CD4+CD8αβ+ CD3− small . | |
| Percentage within total thymocytes ± SD | 2.1 ± 0.3 | 1.5 ± 0.3 | 5.2 ± 0.6 | 3.12 ± 0.2 | 14 ± 2.4 |
| Mean FSC ± SD | 354 ± 9.6 | 349 ± 19.2 | 396 ± 13.6 | 379 ± 15.9 | 298 ± 14.2 |
| Percentage of cycling cells ± SD | 9 ± 2.0 | 10 ± 2.1 | 50 ± 1.2 | 55 ± 3.0 | 9 ± 1.3 |
| TCRβic | − | − | + | + | + |
| CD8β | − | − | + | + | + |
| RAG-1 | ++ | + | + | + | +++ |
| RAG-2 | +++ | ++ | + | + | +/− |
| Rb phosphorylation | hypo | hypo | hyper | hyper | hypo |
| Cyclin A | +/− | +/− | +++ | +++ | +/− |
| Cyclin B | +/− | +/− | +++ | ++ | − |
| . | Thymocyte Population . | ||||
|---|---|---|---|---|---|
| CD4+CD8− CD3− . | CD4+CD8αα+ CD3− . | CD4+CD8αβ+ CD3lowpTα+ . | CD4+CD8αβ+ CD3− large . | CD4+CD8αβ+ CD3− small . | |
| Percentage within total thymocytes ± SD | 2.1 ± 0.3 | 1.5 ± 0.3 | 5.2 ± 0.6 | 3.12 ± 0.2 | 14 ± 2.4 |
| Mean FSC ± SD | 354 ± 9.6 | 349 ± 19.2 | 396 ± 13.6 | 379 ± 15.9 | 298 ± 14.2 |
| Percentage of cycling cells ± SD | 9 ± 2.0 | 10 ± 2.1 | 50 ± 1.2 | 55 ± 3.0 | 9 ± 1.3 |
| TCRβic | − | − | + | + | + |
| CD8β | − | − | + | + | + |
| RAG-1 | ++ | + | + | + | +++ |
| RAG-2 | +++ | ++ | + | + | +/− |
| Rb phosphorylation | hypo | hypo | hyper | hyper | hypo |
| Cyclin A | +/− | +/− | +++ | +++ | +/− |
| Cyclin B | +/− | +/− | +++ | ++ | − |
Pre-T cell subsets were independently isolated from human postnatal thymocytes as described in Materials and Methods. Cell size (FSC), DNA content (percent of cycling cells in S/G2 + M phases), and TCRβic and CD8β expression, was analyzed by flow cytometry, and expression of RAG-1, RAG-2, Rb, and cyclins A and B, by immunoblotting. Data presented as the mean ± SD of five independent experiments.