Prevention of severe splenomegaly upon constitutive or myeloid-specific Ifnγr1 overexpression. (A) Representative macroscopic photos of spleens isolated from mice 9 weeks after infection. Positive control, mouse that received WT cells; negative control, nontransplanted Ifnγr1^−/− mouse. (B) Spleen-to-body weight ratio depicting the normalized spleen weight of individual mice 9 weeks after infection. Mean and SEM are shown for 3 independent experiments (positive control, 10 mice that received WT cells; negative control, 13 mice that received Lv.GFP-transduced Ifnγr1^−/− cells and nontransplanted Ifnγr1^−/− mice; 10 mice received Lv.SFFV.Ifnγr1; 9 mice received Lv.MSP.Ifnγr1; one-way ANOVA using Tukey’s multiple comparisons post hoc testing). (C) Hematoxylin and eosin–stained histologic sections of spleens isolated 9 weeks after infection. Positive controls (mice that received WT cells), Lv.SFFV.Ifnγr1 mice, and Lv.MSP.Ifnγr1 mice showed typical spleen histology with clear separation between white pulp (areas within dotted lines [#]) and red pulp (area indicated by an asterisk), whereas this separation is absent in negative control mice (those that received Lv.GFP-transduced Ifnγr1^−/− cells). Original magnification ×100. (D) BCG CFU counts of spleen homogenates 9 weeks after infection. Mean and SEM are shown for 2 independent experiments (positive control, 7 mice that received WT cells; negative control, 6 mice that received Lv.GFP-transduced Ifnγr1^−/− cells; nontransplanted Ifnγr1^−/− mice: Lv.SFFV.Ifnγr1, n = 4; Lv.MSP.Ifnγr1, n = 5). ***P ≤ .001.