Figure 1. Administration of the anti-HVEM mAb HM3.30 induces erythropoiesis in mice.

(A–D) WT C57BL/6 mice were injected i.p. with 150 μg control Ig or HM3.30 and examined on day 4. (A) Gross appearance of the treated spleen. (B) Absolute numbers of the indicated cell populations per spleen in mice treated with control Ig or HM3.30, examined by flow cytometry (n ≥ 5). *P < 0.01. (C) Percent basophilic (Ter119⁺CD71^hi), polychromatophilic (Ter119⁺CD71^med), and orthochromatic (Ter119⁺CD71^lo) erythroblasts in spleen, examined by flow cytometry. (D) In addition to Ab injection, mice were treated i.p. with 100 μg BrdU every 24 hours. Spleen cells were analyzed for Ter119 and BrdU staining by flow cytometry. Numbers denote the percentage of cells in the respective gates. (E) Absolute number of Ter119⁺CD45^– erythrocytes in the spleen of mice treated with control Ig or HM3.30 as in A–C (n = 3 each). Data represent mean ± SD.