Severe immune deficiency caused by a Pdia6 mutation in mice. (A) Whole blood cell counts of white blood cells, lymphocytes, monocytes, platelets, and neutrophils in 12-wk-old braum/– and WT littermates (n = 8–16 mice/genotype). (B) Representative photographs of spleen and thymus isolated from 4- or 12-wk-old braum/– and WT littermates. (C) Thymocyte and splenocyte counts from 6- or 12-wk-old braum/– and WT littermates (n = 5–8 mice/genotype). (D) Frequency of B220⁺ cells plotted versus frequency of CD3⁺ T cells in peripheral blood from 6- or 12-wk-old braum/– and WT littermates (n = 4–14 mice/group). (E) Frequency of peripheral blood NK and NK1.1⁺ T cells from 12-wk-old braum/– and WT littermates (n = 8–15 mice/genotype). (F) Numbers of B cell subsets in bone marrow, spleen, and peritoneal cavity of 12-wk-old braum/– and WT littermates (n = 4–7 mice/genotype). (G–L) Representative flow cytometry plots showing B cell development in the bone marrow (G and H), spleen (I–K), and peritoneal cavity (L) from 12-wk-old braum/– and WT littermates. Each B cell subset was gated as follows: pre-pro B: B220^lowBP-1⁻CD24^low, pro-B: B220^lowBP-1⁻CD24⁺, pre-B: B220^lowBP-1⁺CD24⁺, immature B (Imm.): B220⁺IgM⁺IgD⁻, transitional B (Trans.): B220⁺IgM^highIgD^low, mature recirculating B: B220⁺IgD⁺IgM⁺, T1: B220⁺CD93⁺IgM^highCD23⁻, T2: B220⁺CD93⁺IgM^highCD23⁺, marginal zone precursor (MZP): B220⁺CD93⁻IgM⁺CD21⁺CD23^high, T3: B220⁺CD93⁺IgM^lowCD23⁺, follicular B (FOB): B220⁺CD93⁻IgM⁺CD21⁺CD23^high, marginal zone B (MZB): B220⁺CD93⁻IgM⁺CD21⁺CD23^low, B2: B220⁺CD19⁺, B1: B220^lowCD19⁺ (n = 4–7 mice/genotype). (M and N) Percentages (M) and numbers (N) of thymocytes in 12-wk-old braum/– and WT littermates (n = 8 mice/genotype). (O) Flow-cytometry analysis of CD44 expression (mean fluorescence intensity, MFI) on splenic CD4⁺ and CD8⁺ T cells in 12-wk-old braum/– and WT littermates (n = 8–15 mice/genotype). (P) Numbers of CD11c⁺ and CD11b⁺ myeloid cells in the spleen of 12-wk-old braum/– and WT littermates (n = 8 mice/genotype). (Q–U) Representative flow cytometry plots (Q–T) and quantitative analysis (U) of the HSC and progenitor populations in the bone marrow of braum/– and WT littermates (n = 5 mice/genotype). Data points represent individual mice (A, C–F, N–P, and U). P values were determined by Student’s t test. Numbers adjacent to outlined areas or in quadrants indicate percent cells in each (G–M and Q–T). Data are representative of three independent experiments (A–U). Error bars indicate SD. *, P < 0.05; **, P < 0.01; ***, P < 0.001. CLP, common lymphoid progenitor; CMP, common myeloid progenitor; GMP, granulocyte-macrophage progenitor; LT, long-term; MEP, megakaryocyte-erythrocyte progenitor; MPP, multipotent progenitor; ST, short-term.