1. In vivo transformation of mouse conventional CD8α+ dendritic cells leads to progressive multisystem histiocytosis
by Quynh-Giao Steiner, Luc A. Otten, M. John Hicks, Gürkan Kaya, Frederic Grosjean, Estelle Saeuberli, Christine Lavanchy, Friedrich Beermann, Kenneth L. McClain, and Hans Acha-Orbea
Blood
Volume 111(4):
February 15, 2008
©2008 by American Society of Hematology

2. Generation and characterization of Mushi Tg mouse lines.
Generation and characterization of Mushi Tg mouse lines. (A) Schematic representation of the Tg construct. The Tg consists of the mouse CD11c promoter, the intron and the polyA addition signal from the rabbit β1 globin gene, the gene coding for SV40 T oncogenes, and a second cistron for eGFP. FRT and loxP sites were added to allow generation of single-copy Tg mice and to remove the expression cassette, respectively. Primers (arrows) flanking the introns of rabbit β1 globin and SV40 T oncogenes were used for screening and to monitor splicing of Tg transcripts. (B) Detection of Tg spliced transcripts coding for SV40 large T and small T antigens by RT-PCR (as described in A) on spleen of the independent Tg lines Mushi1 and Mushi2, littermates (LMs), control genomic Tg DNA (DNA TG), and negative control (TE). (C) FACS analysis of Tg expression. CD11c and GFP levels in spleen Tg Mushi1 and Mushi2 and non-Tg littermate (LM) cells.
Quynh-Giao Steiner et al. Blood 2008;111:
©2008 by American Society of Hematology

3. Mushi1 and 2 mice develop histiocytosis.
Mushi1 and 2 mice develop histiocytosis. (A) The high and low Tg-expressing Mushi1 and Mushi2 lines show an early and late development of disease signs (anemia and general symptoms), respectively. (B) Hematocrit values in percentage of healthy control (LM) and diseased Mushi1 mice (Tg). (C) Multiple nodules and organ enlargement in spleen, liver, and mesenteric LN (MLN) from diseased mice (Mushi1) compared with healthy controls (LM). (D) Similar histologic characteristics in human LCH in LN (human) and Mushi1 liver lesions (TG) are detected by hematoxylin & eosin (H&E) and immunostaining for Langerin (CD207) and S100. (E) Human and Mushi lesions show reniform nuclei (enlargement of D left column). (F) Expression of the cell cycle marker Ki-67 was tested by FACS in gated CD11c− and CD11c+ MLN cells from control (LM) and diseased (TG) mice. (G) Normal human spleen stained with anti-CD1a or anti-Langerin antibodies.
Quynh-Giao Steiner et al. Blood 2008;111:
©2008 by American Society of Hematology

4. Pathologic cells are CD8α+ cDCs.
Pathologic cells are CD8α+ cDCs. (A) CD11c+ DCs were magnetically purified from spleen of WT, healthy (2 months old), and sick Mushi1 Tg mice and analyzed by FACS. The percentage of CD11c+ gated cells expressing the indicated DC subtype marker is shown. (B) The indicated activation markers were analyzed on CD11c+ purified cells from littermate (LM) or sick Mushi1 Tg (TG) mice. CD11c+ CD8α+ gated cells are shown with or without antibody for activation marker (Ab−). (C) Langerin was analyzed on skin-draining LN (pLN), MLN, and spleen cells from littermate (LM) or 3.5-month-old Mushi1 Tg mice with splenomegaly (TG). Fixed and permeabilized CD11c+ CD24+ gated cells are shown with (Ab+) or without (Ab−) Langerin antibody. The percentage of Langerin-positive cells is indicated. (D) The indicated mRNAs were quantified by real-time RT-PCR in magnetically purified B cells and macrophages (Mφ) from WT mice, and FACS-purified spleen CD8α− and CD8α+ DC subsets from Mushi1 sick Tg and non-Tg mice. (E) Levels of CIITA isoform mRNA before and after activation with interferon-γ (IFN-γ) and lipopolysaccharide (LPS) or LPS alone were quantified by real-time RT-PCR using an absolute quantification titration curve. The indicated cells were purified as in panel C.
Quynh-Giao Steiner et al. Blood 2008;111:
©2008 by American Society of Hematology

5. Sick Tg DCs maintain their antigen presentation and cytokine secretion capacity.
Sick Tg DCs maintain their antigen presentation and cytokine secretion capacity. CD11c+ spleen DCs from WT or sick Mushi1 Tg mice were magnetically purified. (A) Ova protein or peptide (cross)-presentation after 1-hour pulsing of irradiated DCs to OTI CD8+ T cells. Proliferation of T cells was measured by 3H-thymidine incorporation after 3 days of coincubation. (B) Ova or peptide presentation of irradiated DCs to OTII CD4+ T cells. Peptide or protein was left in the culture during the 3-day incubation period. Proliferation was measured as in panel A. (C) Secretion of indicated cytokines was measured by ELISA in supernatants of DCs from sick Mushi1 Tg mice that were activated with CpG, poly IC, IFN-γ, IL-4, and GM-CSF or not activated for 18 hours. The mean and standard deviation are shown for triplicate measurements.
Quynh-Giao Steiner et al. Blood 2008;111:
©2008 by American Society of Hematology

6. Preferential transformation of CD8α+ DCs is correlated with absence of Tg expression in DC precursors, increased Tg expression in CD8α+, and higher steady-state proliferation in CD8α+ DCs in Mushi1 and in WT mice.
Preferential transformation of CD8α+ DCs is correlated with absence of Tg expression in DC precursors, increased Tg expression in CD8α+, and higher steady-state proliferation in CD8α+ DCs in Mushi1 and in WT mice. (A) Tg expression is barely detectable in bone marrow DC precursors. Bone marrow cells and CD11c+ magnetically purified splenocytes of indicated mice were analyzed for MHC-II and GFP reporter expression by FACS analysis. CD11c+ gated cells are shown. (B) Expression levels of GFP were analyzed in spleen DC subsets of healthy Mushi1 Tg mice as in panel A. For pDCs, the percentage of B220+ and/or GFP+ cells is indicated. For cDCs, the geometric mean of GFP level is shown in indicated regions of cells stained for CD11b or CD8α. (C) Expression levels of GFP were analyzed in epidermal LCs (gate: CD45+MHCIIhigh), migrated LCs (gate: CD11c+CD205brightCD8α−), and dermal DCs (gate: CD11c+CD205intCD8α−) in skin-draining LNs, and spleen CD8α+ cDCs from 3.5-month-old (Tg) and non-Tg (LM) mice. The percentage and the geometric mean (Geo) of GFP+ cells with the indicated gates are shown. (D) Spleen cells of control from Mushi1 healthy 2-month-old (Tg healthy) and non-Tg (LM) mice were purified and gated as in panel A. In the left part, the percentage of cells positive for CD8α and MHC-II expression are shown. In the right part, the gate positions are indicated. Steady-state proliferation of indicated DC subsets was determined by Hoechst staining. The percentage of S and 4N cells is indicated.
Quynh-Giao Steiner et al. Blood 2008;111:
©2008 by American Society of Hematology