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M. Ichii et al.
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Figure 3. STAP-2 is essential for B-cell recovery during stress hematopoiesis. (A) Percentages of Mac1+ or Gr1+ myeloid (M), CD19+ B, CD3+ T-lineage cells and NK1.1+ natural killer (NK) cells in peripheral blood of STAP-2 transgenic (Tg) and wild-type (WT) mice were analyzed via flow cytometry, and the number of white blood cells (WBC) and different lineages are shown (n=6 in each). (B) Weight of spleen was measured and the ratio to body weight (BW) was calculated (n=6 in each group). (C and D) WT or Tg mice were sub-lethally irradiated (3.5 Gy). (C) Peripheral blood was examined twice per week, and WBC counts were compared at each time point (top panel). Percentages of B220+ CD19+ B cells (bottom panel) were calculated using flow cytometry. Data represent three independent trials with similar results. (D) BrdU was administered 12 hours before analysis of the cell cycle status of B220+ CD19+ cells in bone marrow (BM) via flow cytometry (top panel). Cell apoptosis was analyzed by Annexin V and 7AAD in B220+ cells in BM using flow cytometry (bottom panel). Data were pooled from two independent experiments (n=5 in each). (E) LSK cells (CD45.2+) derived from Tg or WT were injected intravenously with competitor BM cells (CD45.1+) (n=7 in each). Flow cytometry was used to evaluate hematopoietic recovery of myeloid, B- and T-lineage cells in CD45.2+ donor-derived peripheral blood at the indicated time after transplantation (top panels). BM cells were collected one month after transplantation, and donor chimerism (CD45.2+) was evaluated in B-lineage progenitor subsets (bottom panels). Similar results were obtained in two independent experiments. Results are shown as mean±standard deviation. Statistical significances relative to WT control were determined using unpaired two-tailed Mann-Whitney tests: *P<0.05; **P<0.01.
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haematologica | 2021; 106(2)