Phenotypic correction of CD46/Townes mice using ex vivo and in vivo approaches at week 16 after treatment. (A) Blood cell analysis of healthy control CD46tg mice (“CD46tg,” n = 3), untreated CD46/Townes mice (“untreated,” n = 3), primary recipient mice at week 16 after transplantation of ex vivo–transduced BM Lin⁻ cells from CD46/Townes mice (“ex vivo,” n = 5), and CD46/Townes mice at week 16 after in vivo transduction (“in vivo,” n = 7). (B) Representative microphotographs of blood cell and BM smears. First panel: smears of total blood cells subjected to a sickling assay; second panel: blood cell smears stained with Giemsa; third panel: staining of blood smears for reticulocytes with brilliant cresyl blue, which stains nuclear remnants of basophilic ribonucleoproteins in reticulocytes (black arrow); fourth panel: BM smears stained with Giemsa. The red arrow marks an undifferentiated proerythroblast. The blue arrow points at more differentiated erythroblasts or reticulocytes. The scale bars are 20 μm. (C) Percentage of sickle cells in blood smears. Each dot represents the percentage in an individual mouse. (D) Percentage of reticulocytes in blood smears. (E) Upper 2 panels: spleen and liver sections stained with hematoxylin and eosin. Lower 2 panels: tissue hemosiderosis visualized using Perls Prussian blue staining. Iron deposition is shown as cytoplasmic blue pigments of hemosiderin in spleen tissue sections. The scale bars are 200 μm. (F) Spleen sizes (upper panel) and spleen weight relative to body weight (lower panel). Each symbol represents an individual mouse. ∗P < .05. Statistical differences were calculated using one-way ANOVA with Šidák’s multiple comparisons test. HCT, hematocrit; Hb, hemoglobin; LY, lymphocytes; MO, monocytes; NE, neutrophils; PLT, platelets; RBC, red blood cells; WBC, white blood cells.