Improved method to bridge mouse and man
The understanding of human stem cell biology has undergone explosive growth in the past decade, due largely to improvements in immunodeficient mouse xenotransplantation models. Aspects of human stem cell biology such as homing after intravenous infusion and the subsequent differentiation of transplanted stem cells are best studied in vivo. The use of the immunodeficient mouse as a recipient of the human stem cell graft is now a common and cost-effective strategy, and the number of new and improved strains that are available are increasing each year. The most common immunodeficient mouse xenograft strain used to date is the NOD/LtSz-scid/scid (nonobese diabetic–severe combined immunodeficient [NOD/SCID]).1,2 NOD/SCID/beta-2-microglobulin null (NOD/SCID/B2M null) mice have a more absolute immunodeficiency than the NOD/SCID strain and have virtually no natural killer (NK) cell function, so they are highly permissive for acceptance of human stem cells.3-5 Newer strains such as the NOD/LtSz-Rag-1 null mouse,6 the Rag-2 null/common gamma chain null mouse,7-9 and the NOD/SCID/MPSVII (NOD/SCID/mucopolysaccharidosis type VII) mouse10 have all been recently characterized, and each offers a different benefit to the xenotransplantation field.
However, a common theme that runs through all studies involving human hematopoiesis in mice is that the murine growth factors are not suitably cross-reactive to allow development of all human blood cell lineages to maturity. The seminal observation that human cell engraftment in immunodeficient mice was augmented by human-specific cytokines was made by Kamel-Reid and Dick in 1988.11 In this report, human interleukin-3 (IL-3), which is not cross-reactive from mouse to human, was injected intraperitoneally into each mouse every 48 hours, for the duration of each experiment. Although innovative and elegant, this technique was relatively costly and time consuming. Therefore, our group developed a method to deliver human IL-3 and then other cytokines in vivo from engineered marrow stromal cells/mesenchymal stem cells (MSCs) cotransplanted with human hematopoietic stem cells into the mice.12,13 Next, Bock et al generated SCID–transgenic mice expressing the genes for human interleukin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and stem cell factor, and showed an increase in the success of human hematopoietic engraftment14 compared with control SCID mice. This study was accomplished by the generation of human cytokine-transgenic mice in standard strains that are appropriate for conventional plasmid microinjection, followed by extensive backcrossing to move the transgenes onto the SCID strain. It would be very advantageous to now have a method to test production of novel cytokines in the newer, NK-cell–deficient strains of immunodeficient mice that allow enhanced human stem cell engraftment over the traditional SCID strains.
In the current issue, Punzon et al (page 580) report a simplified method for generating human growth factor transgenic immunodeficient mice. They had previously analyzed the capacity of immature human dendritic cells to support HIV-1 infection in immunodeficient mice and found that productive infection is dependent on the presence of exogenously administered recombinant human GM-CSF (rhGM-CSF). Therefore, to provide hGM-CSF in the most convenient manner in the mice, they used direct lentivirus-mediated transgenesis of fertilized oocytes from NOD/SCID mice. This technique proved to be highly efficient in this strain, eliminating the need for microinjection into the conventional strains used for transgenesis and subsequent extensive backcrossing, which is lengthy in a strain such as NOD/SCID where multiple loci are involved in the phenotype. Due to its relative ease and cost effectiveness in comparison with conventional backcrossing, the single cell embryo transduction method should significantly improve the efficiency with which the murine microenvironment can be humanized, allowing improved studies of human stem cell biology in immunodeficient mice.
--- Washington University School of Medicinejcx, 百拇医药
Referencesjcx, 百拇医药
Shultz LD, Schweitzer PA, Christianson SW, et al. Multiple defects in innate and adaptive immunologic function in NOD/LtSz-scid mice. J Immunol. 1995;154: 180-191.jcx, 百拇医药
Prochazka M, Gaskins HR, Shultz LD, Leiter EH. The nonobese diabetic scid mouse: model for spontaneous thymomagenesis associated with immunodeficiency. Proc Natl Acad Sci U S A. 1992;89: 3290-3294.jcx, 百拇医药
Christianson SW, Greiner DL, Hesselton RA, et al. Enhanced human CD4+ T cell engraftment in beta2-microglobulin-deficient NOD-scid mice. J Immunol. 1997;158: 3578-3586.jcx, 百拇医药
Kollet O, Peled A, Byk T, et al. Beta2 microglobulin-deficient (B2m(null)) NOD/SCID mice are excellent recipients for studying human stem cell function. Blood. 2000;95: 3102-3105.jcx, 百拇医药
Glimm H, Eisterer W, Lee K, et al. Previously undetected human hematopoietic cell populations with short-term repopulating activity selectively engraft NOD/SCID-beta2 microglobulin-null mice. J Clin Invest. 2001;107: 199-206.
Shultz LD, Lang PA, Christianson SW, et al. NOD/LtSz-Rag1null mice: an immunodeficient and radioresistant model for engraftment of human hematolymphoid cells, HIV infection, and adoptive transfer of NOD mouse diabetogenic T cells. J Immunol. 2000;164: 2496-2507./{;, http://www.100md.com
Goldman JP, Blundell MP, Lopes L, Kinnon C, Di Santo JP, Thrasher AJ. Enhanced human cell engraftment in mice deficient in RAG2 and the common cytokine receptor gamma chain. Br J Haematol. 1998;103: 335-342./{;, http://www.100md.com
Cooper RN, Irintchev A, Di Santo JP, et al. A new immunodeficient mouse model for human myoblast transplantation. Hum Gene Ther. 2001;12: 823-831/{;, http://www.100md.com
Mazurier F, Fontanellas A, Salesse S, et al. A novel immunodeficient mouse model—RAG2 x common cytokine receptor gamma chain double mutants— requiring exogenous cytokine administration for human hematopoietic stem cell engraftment. J Interferon Cytokine Res. 1999;19: 533-541./{;, http://www.100md.com
Hofling AA, Vogler C, Creer MH, Sands MS. Engraftment of human CD34+ cells leads to widespread distribution of donor-derived cells and correction of tissue pathology in a novel murine xenotransplantation model of lysosomal storage disease. Blood. 2003;101: 2054-2063./{;, http://www.100md.com
Kamel-Reid S, Dick JE. Engraftment of immunedeficient mice with human hematopoietic stem cells. Science. 1988;242: 1706-1709./{;, http://www.100md.com
Nolta JA, Hanley MB, Kohn DB. Sustained human hematopoiesis in immunodeficient mice by cotransplantation of marrow stroma expressing human interleukin-3: analysis of gene transduction of long-lived progenitors. Blood. 1994;83: 3041-3051./{;, http://www.100md.com
Dao MA, Pepper KA, Nolta JA. Long-term cytokine production from engineered primary human stromal cells influences human hematopoiesis in an in vivo xenograft model. Stem Cells. 1997;15: 443-454./{;, http://www.100md.com
Bock TA, Orlic D, Dunbar CE, Broxmeyer HE, Bodine DM. Improved engraftment of human hematopoietic cells in severe combined immunodeficient (SCID) mice carrying human cytokine transgenes. J Exp Med. 1995;182: 2037-2043.(Jan Nolta)
However, a common theme that runs through all studies involving human hematopoiesis in mice is that the murine growth factors are not suitably cross-reactive to allow development of all human blood cell lineages to maturity. The seminal observation that human cell engraftment in immunodeficient mice was augmented by human-specific cytokines was made by Kamel-Reid and Dick in 1988.11 In this report, human interleukin-3 (IL-3), which is not cross-reactive from mouse to human, was injected intraperitoneally into each mouse every 48 hours, for the duration of each experiment. Although innovative and elegant, this technique was relatively costly and time consuming. Therefore, our group developed a method to deliver human IL-3 and then other cytokines in vivo from engineered marrow stromal cells/mesenchymal stem cells (MSCs) cotransplanted with human hematopoietic stem cells into the mice.12,13 Next, Bock et al generated SCID–transgenic mice expressing the genes for human interleukin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and stem cell factor, and showed an increase in the success of human hematopoietic engraftment14 compared with control SCID mice. This study was accomplished by the generation of human cytokine-transgenic mice in standard strains that are appropriate for conventional plasmid microinjection, followed by extensive backcrossing to move the transgenes onto the SCID strain. It would be very advantageous to now have a method to test production of novel cytokines in the newer, NK-cell–deficient strains of immunodeficient mice that allow enhanced human stem cell engraftment over the traditional SCID strains.
In the current issue, Punzon et al (page 580) report a simplified method for generating human growth factor transgenic immunodeficient mice. They had previously analyzed the capacity of immature human dendritic cells to support HIV-1 infection in immunodeficient mice and found that productive infection is dependent on the presence of exogenously administered recombinant human GM-CSF (rhGM-CSF). Therefore, to provide hGM-CSF in the most convenient manner in the mice, they used direct lentivirus-mediated transgenesis of fertilized oocytes from NOD/SCID mice. This technique proved to be highly efficient in this strain, eliminating the need for microinjection into the conventional strains used for transgenesis and subsequent extensive backcrossing, which is lengthy in a strain such as NOD/SCID where multiple loci are involved in the phenotype. Due to its relative ease and cost effectiveness in comparison with conventional backcrossing, the single cell embryo transduction method should significantly improve the efficiency with which the murine microenvironment can be humanized, allowing improved studies of human stem cell biology in immunodeficient mice.
--- Washington University School of Medicinejcx, 百拇医药
Referencesjcx, 百拇医药
Shultz LD, Schweitzer PA, Christianson SW, et al. Multiple defects in innate and adaptive immunologic function in NOD/LtSz-scid mice. J Immunol. 1995;154: 180-191.jcx, 百拇医药
Prochazka M, Gaskins HR, Shultz LD, Leiter EH. The nonobese diabetic scid mouse: model for spontaneous thymomagenesis associated with immunodeficiency. Proc Natl Acad Sci U S A. 1992;89: 3290-3294.jcx, 百拇医药
Christianson SW, Greiner DL, Hesselton RA, et al. Enhanced human CD4+ T cell engraftment in beta2-microglobulin-deficient NOD-scid mice. J Immunol. 1997;158: 3578-3586.jcx, 百拇医药
Kollet O, Peled A, Byk T, et al. Beta2 microglobulin-deficient (B2m(null)) NOD/SCID mice are excellent recipients for studying human stem cell function. Blood. 2000;95: 3102-3105.jcx, 百拇医药
Glimm H, Eisterer W, Lee K, et al. Previously undetected human hematopoietic cell populations with short-term repopulating activity selectively engraft NOD/SCID-beta2 microglobulin-null mice. J Clin Invest. 2001;107: 199-206.
Shultz LD, Lang PA, Christianson SW, et al. NOD/LtSz-Rag1null mice: an immunodeficient and radioresistant model for engraftment of human hematolymphoid cells, HIV infection, and adoptive transfer of NOD mouse diabetogenic T cells. J Immunol. 2000;164: 2496-2507./{;, http://www.100md.com
Goldman JP, Blundell MP, Lopes L, Kinnon C, Di Santo JP, Thrasher AJ. Enhanced human cell engraftment in mice deficient in RAG2 and the common cytokine receptor gamma chain. Br J Haematol. 1998;103: 335-342./{;, http://www.100md.com
Cooper RN, Irintchev A, Di Santo JP, et al. A new immunodeficient mouse model for human myoblast transplantation. Hum Gene Ther. 2001;12: 823-831/{;, http://www.100md.com
Mazurier F, Fontanellas A, Salesse S, et al. A novel immunodeficient mouse model—RAG2 x common cytokine receptor gamma chain double mutants— requiring exogenous cytokine administration for human hematopoietic stem cell engraftment. J Interferon Cytokine Res. 1999;19: 533-541./{;, http://www.100md.com
Hofling AA, Vogler C, Creer MH, Sands MS. Engraftment of human CD34+ cells leads to widespread distribution of donor-derived cells and correction of tissue pathology in a novel murine xenotransplantation model of lysosomal storage disease. Blood. 2003;101: 2054-2063./{;, http://www.100md.com
Kamel-Reid S, Dick JE. Engraftment of immunedeficient mice with human hematopoietic stem cells. Science. 1988;242: 1706-1709./{;, http://www.100md.com
Nolta JA, Hanley MB, Kohn DB. Sustained human hematopoiesis in immunodeficient mice by cotransplantation of marrow stroma expressing human interleukin-3: analysis of gene transduction of long-lived progenitors. Blood. 1994;83: 3041-3051./{;, http://www.100md.com
Dao MA, Pepper KA, Nolta JA. Long-term cytokine production from engineered primary human stromal cells influences human hematopoiesis in an in vivo xenograft model. Stem Cells. 1997;15: 443-454./{;, http://www.100md.com
Bock TA, Orlic D, Dunbar CE, Broxmeyer HE, Bodine DM. Improved engraftment of human hematopoietic cells in severe combined immunodeficient (SCID) mice carrying human cytokine transgenes. J Exp Med. 1995;182: 2037-2043.(Jan Nolta)