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Gene transfer into hematopoietic stem cells reduces HLH manifestations in a murine model of Munc13-4 deficiency

Tayebeh Soheili, Amandine Durand, Fernando E. Sepulveda, Julie Rivière, Chantal Lagresle-Peyrou, Hanem Sadek, Geneviève de Saint Basile, Samia Martin, Fulvio Mavilio, Marina Cavazzana and Isabelle André-Schmutz

Article Figures & Data

Figures

  • Figure 1.

    Chimerism and immune system reconstitution in Jinx mice after transfer of the human UNC13D gene into murine HSCs. (A) A schematic representation of the transplantation and infection protocol in mice. Sublethally irradiated (7 Gy) Jinx 45.1/2 recipients were reconstituted with Sca1+ murine HSCs transduced with a Munc13-4- or GFP-expressing LV from Jinx 45.2 mice (the J/Munc and J/GFP groups, respectively) or nontransduced Sca1+ cells from B6 45.1 mice (the J/B6 group). Each mouse received total number of 2.5 × 105 Sca1+ cells. Mice 4 to 6 months posttransplantation were infected with LCMV (intraperitoneal injection, 200 pfu). Euthanasia time: 14 days after LCMV infection. (B) Flow cytometry analysis showing that more than 90% of the cells in the bone marrow and spleen were derived from the donor in all groups at euthanasia. (C) Flow cytometry analysis of various spleen cell subsets in the control groups (B6 and Jinx mice) and transplanted groups. Data are presented as the mean ± standard deviation percentage (first graph) and the absolute count (second graph) for each subset within the spleen. B6 (n = 10), Jinx (n = 10), J/GFP (n = 8), J/B6 (n = 11), and J/Munc (n = 12). *P < .05 using unpaired Student t test. (D) Flow cytometry analysis of Munc13-4/GFP (optimized human Munc13-4 fused to GFP) expression in Sca1+ cells, 48 hours after transduction (n = 3 mice).

  • Figure 2.

    Human Munc13-4 transgene integration and expression. (A) The transgene VCN and mRNA expression were measured by qPCR in the J/Munc group (absolute and relative amounts, respectively), and the result is presented as a correlation graph (r = 0.52; P = .04). (B) Flow cytometry analysis showing expression of the Munc13-4/GFP fusion protein 4 to 6 months after transplantation in the bone marrow (BM) for Sca1+ cells and in the spleen for various cell subsets.

  • Figure 3.

    HLH-like manifestation after LCMV infection in different mouse groups. (A) Serum cytokine levels were assayed 8 days after LCMV infection. Levels were lower in the treated groups (J/B6 and J/Munc) compared with nontreated controls. (B) Body weight and temperature were measured every 2 days postinfection; the intergroup difference was significant at euthanasia (D14 postinfection). Body weight is presented as a percentage of the value on D0 (the day of infection). (C) At euthanasia, the WBC and RBC counts were measured. All data are presented as the mean ± standard error of the mean. Sahpiro-Wilk test was used to evaluate the normal distribution of the data. P values were calculated using a Mann-Whitney U test for IL-6 and TNF-α levels (which are not normally distributed) and an unpaired Student t test for all other parameters. *P < .05; **P < .01; ***P < .001; ****P < .0001. Hct, hematocrit.

  • Figure 4.

    Hepatomegaly and liver damage. (A) Liver weight is presented as a percentage of body weight. (B) Serum levels of aspartate transaminase (ASAT), alanine transaminase (ALAT), and lactate dehydrogenase (LDH). Data are presented as the mean ± standard error of the mean. P values were calculated using an unpaired Student t test. (C) Hematoxylin and eosin staining of liver sections at day 14 postinfection. Inflammatory infiltrates are depicted with arrows (upper panel: 10× objective; lower panel: 25× objective). Representative sections are shown. *P < .05; **P < .01; ***P < .001.

  • Figure 5.

    Functional and phenotypic characterization of CD8+CTLs. (A) To assess degranulation activity, splenic CD8+ T cells were stimulated with murine anti-CD3 (3 µg/mL). Surface expression of CD107a was determined by flow cytometry and presented as percentage of CD8+ population that was CD107a+. P values were calculated using an unpaired Student t test. (B) The viral titer in the liver was measured by a qPCR assay of amplified LCMV mRNA and was normalized against levels of endogenous murine β-actin. The data are presented in a box plot, and P values were determined using a Kruskal-Wallis test for multiple comparisons. Representative fluorescence-activated cell sorter plots (C) and a bar graph (D) showing the distribution of CD8+ T-cell subsets (mean ± standard deviation) at euthanasia (TN: CD62L+CD44; TCM: CD62L+CD44+; TEM: CD44+CD62L). *P < .1; **P < .01; ***P < .001; ****P < .0001.