Publications by authors named "Tomoyuki Ogura"

Article Synopsis
  • Humanized mice created by transferring human stem cells into a specific type of NOG mouse develop mature human lymphoid cells, but struggle to produce fully differentiated human dendritic cells (DCs), which are vital for T cell activation.
  • Researchers engineered a new mouse model (hFLT3L-Tg) to promote human DC development, but encountered issues with low human cell engraftment due to interference from mouse myeloid cells caused by receptor cross-reactivity.
  • To resolve this, they utilized CRISPR technology to create a mouse model (FL Tg/KO) that blocks this interference, allowing for successful human cell engraftment and differentiation of various human DC types, making it a promising tool for studying human immune responses
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Here, we report the identification of causative genes for limb-shortening in individuals repeatedly found in a population of severely immunodeficient NOG mice maintained via sibling mating. First, we conducted a pedigree survey to determine whether limb-shortening was a recessive genetic trait and then identified it using a crossing test. Simultaneously, the symptoms were identified in detail using pathological analysis.

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Human hematopoietic stem cell (HSC)-transferred humanized mice are valuable models for exploring human hematology and immunology. However, sufficient recapitulation of human hematopoiesis in mice requires large quantities of enriched human CD34 HSCs and total-body irradiation for adequate engraftment. Recently, we generated a NOG mouse strain with a point mutation in the c-kit tyrosine kinase domain (W41 mutant; NOGW mice).

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Humanized mice are widely used to study the human immune system in vivo and investigate therapeutic targets for various human diseases. Immunodeficient NOD/Shi-scid-IL2rγ (NOG) mice transferred with human hematopoietic stem cells are a useful model for studying human immune systems and analyzing engrafted human immune cells. The gut microbiota plays a significant role in the development and function of immune cells and the maintenance of immune homeostasis; however, there is currently no available animal model that has been reconstituted with human gut microbiota and immune systems in vivo.

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Neutrophils are critical mediators during the early stages of innate inflammation in response to bacterial or fungal infections. A human hematopoietic system reconstituted in humanized mice aids in the study of human hematology and immunology. However, the poor development of human neutrophils is a well-known limitation of humanized mice.

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Astroviruses are often associated with gastrointestinal diseases in mammals and birds. Murine astrovirus (MuAstV) is frequently detected in laboratory mice. Previous studies on MuAstV in mice did not report any symptoms or lesions.

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Humanized mice are widely used to study the human immune system in vivo and develop therapies for various human diseases. Human peripheral blood mononuclear cells (PBMC)-engrafted NOD/Shi-scid IL2rγ (NOG) mice are useful models for characterization of human T cells. However, the development of graft-versus-host disease (GVHD) limits the use of NOG PBMC models.

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To avoid microbial contamination risk, vinyl film isolators are generally used in animal microbiome experiments involving germ-free (GF) mice and/or gnotobiotic (GB) mice. However, it can take several months to gain expertise in operating the isolator competently. Furthermore, sterilization and sterility testing, which are essential for isolator preparation, can take more than 20 days.

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Although Th17 cells are closely linked to cutaneous graft-versus-host-disease (GVHD) in mouse models, this association remains unclear in human GVHD. In this study, we established a novel xenogeneic cutaneous GVHD model using humanized mice. To induce the differentiation of human Th17 cells, we created transgenic NOG mice expressing human IL-1β and IL-23 cytokines (hIL-1β/23 Tg) and transplanted with human CD4 T cells.

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Asthma is one of the most common immunological diseases and is characterized by airway hyperresponsiveness (AHR), mucus overproduction, and airway eosinophilia. Although mouse models have provided insight into the mechanisms by which type-2 cytokines induce asthmatic airway inflammation, differences between the rodent and human immune systems hamper efforts to improve understanding of human allergic diseases. In this study, we aim to establish a preclinical animal model of asthmatic airway inflammation using humanized IL-3/GM-CSF or IL-3/GM-CSF/IL-5 Tg NOD/Shi-scid-IL2rγnull (NOG) mice and investigate the roles of human type-2 immune responses in the asthmatic mice.

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We generated a novel mouse strain expressing transgenic human interleukin-15 (IL-15) using the severe immunodeficient NOD/Shi-scid-IL-2Rγ (NOG) mouse genetic background (NOG-IL-15 Tg). Human natural killer (NK) cells, purified from the peripheral blood (hu-PB-NK) of normal healthy donors, proliferated when transferred into NOG-IL-15 Tg mice. In addition, the cell number increased, and the hu-PB-NK cells persisted for 3 months without signs of xenogeneic graft versus host diseases (xGVHD).

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Severely immunodeficient NOD/Shi-scid, IL-2Rγ (NOG) mice provide an in vivo model for human cell/tissue transplantation studies. NOG mice were established by combining interleukin-2 receptor-γ chain knockout mice and NOD/Shi-scid mice. They exhibit a high incidence of thymic lymphomas and immunoglobulin (Ig) leakiness.

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Most in vivo studies on the conversion to insulin-producing cells with AAV carrying PDX1 gene are performed in rodents. However, there is little information regarding Adeno-associated virus (AAV) carrying PDX1 gene transduced to human liver in vivo because accidental death caused by unpredicted factors cannot be denied, such as the hypoglycemic agent troglitazone with hepatic failure. Here we aim to confirm insulin secretion from human liver transduced with AAV carrying PDX1 gene in vivo and any secondary effect using a humanized liver mouse.

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We generated a severe immunodeficient NOD/Shi-scid-IL-2Rγ(null) (NOG) mouse substrain expressing the transgenic human IL-2 gene (NOG-IL-2 Tg). Upon transfer of human cord blood-derived hematopoietic stem cells (HSCs), CD3(-)CD56(high)CD16(+/-) cells developed unexpectedly, predominantly in the NOG-IL-2 Tg (hu-HSC NOG-IL-2 Tg). These cells expressed various NK receptors, including NKp30, NKp44, NKp46, NKG2D, and CD94, as well as a diverse set of killer cell Ig-like receptor molecules at levels comparable to normal human NK cells from the peripheral blood, which is evidence of their maturity.

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We have developed NOD-Rag2(null) IL-2Rγ(null) (NR2G) mice similar to NOD-scidIL-2Rγ(null) (NOG) mice that are known as an excellent host to generate humanized mice. To evaluate the usefulness of NR2G mice as a host for humanized mice, the engraftment rates and differentiation of human cells after human hematopoietic stem cell (HSC) transplantation were compared among NR2G, NOG, and NOD-scid mice. For this purpose, the appropriate irradiation doses to expand the niche for human stem cells in the bone marrow were first determined.

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Here, we present a versatile method for detecting human tumor xenografts in vivo, based on the enhanced permeability and retention (EPR) effect, using near-infrared (NIR) fluorochrome-conjugated macromolecule probes. Bovine serum albumin (BSA) and two immunoglobulins-an anti-human leukocyte antigen (HLA) monoclonal antibody and isotype control IgG2a-were labeled with XenoLight CF770 fluorochrome and used as NIR-conjugated macromolecule probes to study whole-body imaging in a variety of xenotransplantation mouse models. NIR fluorescent signals were observed in subcutaneously transplanted BxPC-3 (human pancreatic cancer) cells and HCT 116 (colorectal cancer) cells within 24 h of NIR-macromolecule probe injection, but the signal from the fluorochrome itself or from the NIR-conjugated small molecule (glycine) injection was not observed.

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The development of animal models that mimic human allergic responses is crucial to study the pathophysiology of disease and to generate new therapeutic methodologies. Humanized mice reconstituted with human immune systems are essential to study human immune reactions in vivo and are expected to be useful for studying human allergies. However, application of this technology to the study of human allergies has been limited, largely because of the poor development of human myeloid cells, especially granulocytes and mast cells, which are responsible for mediating allergic diseases, in conventional humanized mice.

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Problem: To study the histopathology and expression of apoptosis in placenta of pregnancy-complicated antiphospholipid syndrome (APS)-positive mouse models.

Method Of Study: ICR mice were immunized with IgG isotype of human anticardiolipin (aCL) and/or lupus anticoagulant (LA). The pathological and apoptotic expression was studied in the placenta of positive APS mice and compared with respective control samples.

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NOD/Shi-scid IL2rγnull (NOG) mice with severe immunodeficiency are excellent recipients to generate "humanized" mice by the transplantation of human CD34(+) hematopoietic stem cells (HSCs). In this study, we developed NOG mice carrying a human Delta-like1 (DLL1) gene, which is a ligand of the Notch receptor and is known to be important in HSC maintenance and self-renewal. We also analyzed the effect of DLL1 signaling on human hematopoiesis and HSC maintenance using humanized DLL1 transgenic NOG mice.

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An animal model for the early detection of common fatal diseases such as ischemic diseases and cancer is desirable for the development of new drugs and treatment strategies. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that regulates oxygen homeostasis and plays key roles in a number of diseases, including cancer. Here, we established transgenic (Tg) mice that carry HRE/ODD-luciferase (HOL) gene, which generates bioluminescence in an HIF-1-dependent manner and was successfully used in this study to monitor HIF-1 activity in ischemic tissues.

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Problem: Antiphospholipid antibodies have been investigated both in humans and in animal models. In contrast, there are fewer reports describing anti-phosphatidylethanolamine (aPE) antibodies in humans, and there are no reports of animal studies with aPE till date. Clinically, FXII deficiency or anti-FXII antibodies are sometimes associated with aPE in patients with recurrent pregnancy loss.

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Background: Several animal models for xenogenic (xeno) graft versus host disease (GVHD) have been developed in immunodeficient mice, such as C.B-17-scid and nonobese diabetes (NOD)/severe combined immunodeficiency (SCID), by human peripheral blood mononuclear cell (hPBMC) transplantation. However, these models pose problems because they require sublethal total body irradiation of the mice and a large number of hPBMCs to induce GVHD, and the timing of onset of GVHD is also unstable.

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Severely immunocompromised NOD/Shi-scid IL2Rg (null) (NOG) mice, which show higher engraftment efficiency, are useful as recipients in xenotransplantation studies. We generated a NOG-enhanced green fluorescent protein (EGFP) transgenic (Tg) mouse (NOG-EGFP) that was introduced the EGFP transgene from the C57BL/6-EGFP Tg mouse using the speed congenic method with a marker-assisted selection protocol (MASP). With this method, the selection of the male with the closest NOG strain type was repeated four times.

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CXCR4-tropic (X4) human immunodeficiency virus type 1 (HIV-1) does not efficiently infect and replicate in severe combined immunodeficiency (SCID) mice reconstituted with human peripheral blood mononuclear cells, termed "hu-PBL-SCID mice," due to, at least in part, relatively low levels of expression of the CXCR4 coreceptor. To overcome this limitation, interleukin (IL)-4-transgenic hu-PBL-SCID mice were derived that spontaneously synthesized human IL-4, which has been shown to enhance CXCR4 expression and promote X4 virus infection in vitro. Experiments reported here show that (1) synthesis of human IL-4 in vivo augmented CXCR4 expression on human CD4(+) lymphocytes and importantly led to productive infection of not only X4 HIV-1(NL4-3) but also multidrug-resistant primary clinical isolates and that (2) the in vivo infection could be significantly blocked by the administration of a CXCR4 antagonist.

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