CD62L⁻ T cells enhance stem cell–mediated T-cell regeneration. (A) Purified hematopoietic stem cells (KTLS, 5 × 10³) from B6 CD45.1 mice and CD62L⁻ T cells (1 × 10⁶) from B6 CD45.2 mice were transplanted into lethally irradiated BALB/c recipients. T-cell reconstitution was monitored at different times in peripheral blood by flow cytometry. Data represent absolute counts in peripheral blood (mean ± SD/μL blood). Each group contained 5 mice (*P < .05 between groups). (i) CD4⁺ T cells. (ii) CD8⁺ T cells. KTLS indicates c-Kit⁺Thy1.1^lowLin^−/lowSca-1⁺ hematopoietic stem cells. (B-C) TCD BM cells (1 × 10⁷) from B6 CD45.2 mice and CD62L⁻ T cells (1 × 10⁶) from B6 CD45.1 mice were transplanted into irradiated BALB/c or SCID or NSG recipients. T-cell reconstitution was monitored in peripheral blood at different times after transplantation by flow cytometry. Data represent absolute counts in peripheral blood (mean + SD/μL blood). Each group contained 5 to 10 animals. The data were pooled from 2 independent experiments. Fold increase of peripheral T-cell counts in CD62L⁻ T-cell recipients over TCD BM only control is shown in C (*P < .05, TCD BM only vs CD62L⁻; #P < .05, BALC/c vs SCID or NSG; &P < .05, SCID vs NSG).