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H Kaneshima

Publications and source records attributed to H Kaneshima.

At least 37 records · Page 2Linked to original sources
PubMed1997

The SCID-hu mouse: an in vivo model for HIV-1 infection in humans.

The lack of suitable animal models for the in vivo study of HIV-1 infection has prompted investigators to take advantage of the graft-rejection deficit in severe combined immunodeficient (SCID) mice. Two separate approaches have been used to transplant human lymphoid and/or hemolymphoid tissues into SCID mice to generate chimeric animals in which distinct elements of the human immune system could be maintained and studied in vivo. The two models that arose from this work were the SCID-hu mouse and hu-PBL-SCID mouse. The goal of producing these distinct models is to provide an easily manipulable model for the in vivo analysis of HIV-1 infection and its ensuing pathophysiology. Both models support HIV-1 replication and display potential as models for studying antiviral strategies and mechanisms of viral pathogenesis. This review focuses on the SCID-hu mouse.

Acquired Immunodeficiency Syndrome↗
PubMed1997

RevM10-expressing T cells derived in vivo from transduced human hematopoietic stem-progenitor cells inhibit human immunodeficiency virus replication.

A key feature of the pathogenesis of human immunodeficiency virus type 1 (HIV-1) infection is the gradual loss of CD4-positive T cells. A number of gene therapy strategies have been designed with the intent of inhibiting HIV replication in mature T cells. As T cells are products of hematolymphoid differentiation, insertion of antiviral genes into hematopoietic stem cells could serve as a vehicle to confer long-term protection in progeny T cells derived from transduced stem cells. One such "cellular immunization" strategy utilizes the gene coding for the HIV-1 rev trans-dominant mutant protein RevM10 which has been demonstrated to inhibit HIV-1 replication in T-cell lines and in primary T cells. In this study, we used a Moloney murine leukemia virus-based retrovirus encoding a bicistronic message coexpressing RevM10 and the murine CD8-alpha' chain (Lyt2). This vector allows rapid selection of transgene-expressing cells as well as quantitation of transgene expression. We demonstrate that RevM10-transduced CD34-enriched hematopoietic progenitor-stem cells (HPSC) isolated from human umbilical cord blood or from granulocyte colony-stimulating factor-mobilized peripheral blood can give rise to mature thymocytes in the SCID-hu thymus/liver mouse model. The phenotypic distribution of HPSC-derived thymocytes is normal, and expression of the transgene can be detected by flow cytometric analysis. Moreover, we demonstrate that RevM10 can inhibit HIV replication in T cells derived from transduced HPSC after expansion in vitro. This is the first demonstration of anti-HIV efficacy in T cells derived from transduced human HPSC.

Animals↗
PubMed1997

[A case of pulmonary sarcoidosis mimicking relapse of pulmonary tuberculosis].

A 61-year-old woman was suspected of relapse of pulmonary tuberculosis. A chest X-ray film taken at a regular health check-up suggested relapse of pulmonary tuberculosis in a 61-year-old woman. Chest X-ray revealed irregular shadow with calcification in the upper lobe of the left lung and pulmonary tuberculosis was initially diagnosed a despite a negative reaction for acid-fast bacilli on examination of her sputum and bronchial lavage. Chest CT revealed thickened bronchi and blood vessels and nodules in the lung field. Transbronchial by biopsy failed to reveal caseating epithelioid cell granulomas transbronchial lung biopsy. Past history of facial palsy, uveitis, high plasma levels of angiotensin-converting enzyme (31.6IU/L), and abnormal HRCT levels. Bronchoalveolar lavage analysis revealed an increase in lymphocytes and a CD4/CD8 ratio of 8.67. Sarcoidosis was diagnosed after a liver biopsy. This appears that HRCT findings are useful in the diagnosis of pulmonary sarcoidosis.

Diagnosis, Differential↗
PubMed1996

HIV-1-associated pathology in hemato-lymphoid organs and the experimental evaluation in the SCID-hu mouse.

A variety of possible mechanisms for the loss of CD4+ T cells has been proposed, such as direct cytopathic effects by HIV-1 infection, and indirect induction of apoptosis. However, the fundamental picture of major and central pathogenic processes for the decay of immune systems is still missing in understanding the pathogenic mechanisms of HIV-1 infected humans. It is more appropriate to expand our focus onto entire organ systems involved in the development of immune system such as bone marrow and thymus. From the observations in the clinical studies, HIV-1 causes a variety of pathology on the T cell development pathway even from the hematopoietic progenitors and immature thymocytes, which should have a substantial impact on the failure of T cell homeostasis in the periphery. The SCID-hu mouse constructed by surgical implantation of human fetal hemato-lymphoid organs into the immunodeficient mouse has been used for the experimental evaluation of various parameters associated with HIV-1 infection and hematosuppression. Given the apparently normal structure and function of the human implants, the SCID-hu bone and Thy/Liv mice would appear to be potentially reliable models for the analysis of human physiology and patho-physiology.

AIDS-Related Opportunistic Infections↗
PubMed1996

Use of standardized SCID-hu Thy/Liv mouse model for preclinical efficacy testing of anti-human immunodeficiency virus type 1 compounds.

We have developed standardized procedures and practices for infection of SCID-hu Thy/Liv mice with human immunodeficiency virus type 1 for the prophylactic administration of antiviral compounds and for evaluation of the antiviral effect in vivo. Endpoint analyses included quantitation of viral load by intracellular p24 enzyme-linked immunosorbent assay, DNA PCR for the presence of proviral genomes, flow cytometry to measure the representation of CD4+ and CD8+ cells, and cocultivation for the isolation of virus. Efficacy tests in this model are demonstrated with the nucleoside analogs zidovudine and dideoxyinosine and with the nonnucleoside reverse transcriptase inhibitor nevirapine. This small-animal model should be particularly useful in the preclinical prioritization of lead compounds within a common chemical class, in the evaluation of alternative in vivo dosing regimens, and in the determination of appropriate combination therapy in vivo.

Animals↗
PubMed1996

Intracellular expression of RNA transcripts complementary to the human immunodeficiency virus type 1 gag gene inhibits viral replication in human CD4+ lymphocytes.

Intracellular expression of antisense transcripts was evaluated for its potential to interfere with human immunodeficiency virus type 1 (HIV-1) replication. Retroviral vectors encoding HIV-1 psi-gag complementary sequences downstream of a selectable gene (neo, puromycin gene, or Lyt2 gene) were stable and yielded high titers. Human CEMSS T cells were transduced with amphotropic retroviral vectors to express RNA complementary to the psi-gag sequence of HIV-1. Replication of laboratory-adapted HIV-1 strains was inhibited by more than 1 order of magnitude (log10) in these transduced cells even at high inoculation doses (4 x 10(4) 50% tissue culture infective doses). Antisense-mediated anti-HIV efficacy was further demonstrated by survival of CD4+ cells in these cultures relative to controls. The level of anti-HIV-1 activity of the psi-gag antisense sequence correlated with the length of the antisense transcript. Maximal anti-HIV efficacy was observed with complementary sequence more than 1,000 nucleotides long, whereas transcripts less than 400 nucleotides long failed to inhibit HIV-1 replication. Expression of psi-gag antisense RNA also reduced HIV-1 JR-CSF replication 10-fold in primary CD4+ lymphocytes. These results obtained with a T-cell line and primary peripheral blood lymphocytes indicate the potential of long antisense RNAs as an efficient anti-HIV-1 therapeutic agent for gene therapy.

Anti-HIV Agents↗
PubMed1996

Measles virus infection of thymic epithelium in the SCID-hu mouse leads to thymocyte apoptosis.

Mortality from measles is caused mostly by secondary infections associated with the depression of cellular immunity. The mechanism of immune suppression and the role of virus strain differences on the immune system are incompletely understood. SCID-hu mice were used to determine the effects of virulent, wild-type (Chicago-1) and avirulent, vaccine (Moraten) strains of measles virus (MV) on the human thymus in vivo. Chicago-1 replicated rapidly, with a 100-fold decrease in numbers of thymocytes, whereas Moraten replicated slowly, without significant thymocyte death. Productive MV infection occurred not in thymocytes but in thymic epithelial and myelomonocytic cells. Wild-type MV infection of thymic stromata leads to induction of thymocyte apoptosis and may contribute to a long-term alteration of immune responses. The extent of thymic disruption reflects the virulence of the virus, and therefore the SCID-hu mouse may serve as the first small animal model for the study of MV pathogenesis.

Animals↗
PubMed1995

Human allogeneic stem cell maintenance and differentiation in a long-term multilineage SCID-hu graft.

The ability to determine the functional capacity of putative human hematopoietic stem cell (HSC) populations requires in vivo assays in which long-term multilineage differentiation can be assessed. We hypothesized that if human fetal bone was transplanted adjacent to a fetal thymus fragment in severe combined immunodeficient (SCID) mice, a conjoint organ might form in which HSC in the human bone marrow (BM) would mimic human multilineage differentiation into progenitor cells, B cells, and myeloid cells; undergo self-renewal; and migrate to and differentiate into T cells within the thymic microenvironment. To test this possibility, SCID mice were transplanted subcutaneously with HLA class I mismatched fetal bone, thymus, and spleen fragments (SCID-hu BTS). We found that the BM of SCID-hu BTS grafts maintained B cells, myeloid cells, CD34+ cells for at least 36 weeks posttransplant. Assayable hematopoietic progenitors colony-forming units-granulocyte-macrophage were present in 100% (66/66) of grafts over a period of 28 weeks. Cells with a HSC phenotype (CD34+Thy-1+Lin-) were maintained for 20 weeks in SCID-hu BTS grafts. These CD34+Thy-1+Lin- cells had potent secondary multilineage reconstituting potential when isolated and injected into a secondary HLA mismatched SCID-hu bone assay and analyzed 8 weeks later. In addition, early progenitors within the BM of SCID-hu BTS grafts were capable of migrating to the human thymus and undergoing differentiation through immature CD4+CD8+ double-positive T cells and produce mature T cells with a CD4+CD8- or CD8+CD4- phenotype that could be detected for at least 36 weeks. Phenotypically defined human fetal liver (FL) and umbilical cord blood (UCB) hematopoietic stem cell populations were injected into irradiated SCID-hu BTS grafts to assess their multilineage repopulating capacity and to assess the ability of the BTS system to provide an environment where multiple lineages might differentiate from a common stem cell pool. Injection of irradiated grafts with FL HSC or UCB HSC cells resulted in donor-derived B cells, myeloid cells, immature and mature T cells, and CD34+ cells in individual grafts when analyzed 8 weeks postreconstitution, further showing the multipotential nature of these stem cell populations. In addition, a strong correlation was observed between maintenance of host graft-derived CD8+ cells and failure of donor stem cell engraftment.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

HIV-1-induced thymocyte depletion is associated with indirect cytopathogenicity and infection of progenitor cells in vivo.

Direct and indirect cytopathic mechanisms have been proposed to account for the loss of CD4+ T cells after infection with human immunodeficiency virus type 1 (HIV-1). We report here that HIV-1 infection of the human thymus in vivo results in thymocyte depletion by at least two different mechanisms. Thymocytes within multiple stages of differentiation are induced to die of apoptosis; most of these cells are uninfected. Additionally, thymopoiesis is interrupted by direct infection and destruction of intrathymic CD3-CD4+CD8- progenitor cells. These mechanisms are differentially induced by distinct isolates of HIV-1.

Animals↗
PubMed1995

Development of a human thymic organ culture model for the study of HIV pathogenesis.

The development of effective therapies for the treatment of AIDS would be facilitated by a better understanding of HIV pathogenesis in vivo. While some aspects of pathogenesis may be assessed by standard tissue culture assays, in vivo animal models may provide clues to other aspects of HIV-mediated progression toward AIDS. Current animal models include primate models for the study of simian immunodeficiency virus (SIV) and HIV, SCID-hu and hu-PBL SCID mouse models for the study of HIV, and feline models for the study of feline immunodeficiency virus (FIV). In general these models are costly and labor intensive. We have developed a simple human fetal thymic organ culture (TOC) system that is permissive for HIV infection and that exhibits pathology similar to that observed in vivo. A key feature of this system is the time-dependent destruction of thymocytes typified by the preferential loss of CD4-expressing cells. HIV-mediated thymocyte destruction occurs by a process involving programmed cell death. We have infected TOC with a panel of HIV isolates and found that the resulting viral replicative and pathogenic profiles are similar to those seen in the SCID-hu Thy/Liv mouse, yet different from profiles observed in standard PHA-blast tissue culture assays. In addition, we find that TOC may be used to assess efficacy of antiviral agents such as AZT (3'-azido-3'-deoxythymidine) and ddI (2',3'-dideoxyinosine) in blocking both viral replication and virus-induced pathology. These results indicate that this model is amenable to the systematic manipulation, analysis, and characterization of a variety of HIV virus isolates and antiviral therapies.

Animals↗
PubMed1995

Dramatic interstrain differences in the replication of human cytomegalovirus in SCID-hu mice.

The ability of a low-passage strain (Toledo) and laboratory strains (AD169 and Towne) of human cytomegalovirus to replicate in SCID-hu (thymus plus liver) mice were compared. At a time of peak replication, 14 days after inoculation, the Toledo strain grew 2-3 orders of magnitude better than any laboratory strain, a difference reflecting the number of infected thymic stromal cells in the implants. The growth property of the Toledo strain was stable through serial passage and plaque purification. The AD169-ATCC strain failed to grow at all, while an independently maintained stock of this strain obtained from the United Kingdom replicated to low levels, suggesting that divergence had occurred during propagation in different locations. This work predicts the existence of viral genetic determinant(s) for growth in tissues that are lost during propagation in culture.

Animals↗
PubMed1995

Tropism of varicella-zoster virus for human CD4+ and CD8+ T lymphocytes and epidermal cells in SCID-hu mice.

To investigate the cell tropism and pathogenicity of varicella-zoster virus (VZV) strains, we analyzed VZV replication by using SCID-hu mice that carry human fetal thymus/liver implants under the kidney capsule or as subcutaneous fetal skin implants. MRC-5 cells infected with wild-type VZV or the Oka strain, used in the live attenuated varicella vaccine, were injected into the implants. The implants were surgically removed 2, 7, 14, and 21 days postinfection. The VZV titer from infected thymus/liver implants peaked on day 7 for the wild-type strain and on day 14 for the Oka strain. Histological analysis showed necrotic areas characterized by thymocyte depletion and fibrosis. VZV protein synthesis was detectable by immunohistochemical staining in the necrotic areas and in distant regions that did not show cytopathic changes, and VZV DNA was detected by in situ hybridization in the same distribution. Fluorescence-activated cell sorting analysis of thymocytes harvested at day 7 postinfection showed that VZV proteins were expressed in CD4+, CD8+, and CD4+ CD8+ T cells; VZV was cultured from each T-cell subpopulation. The Oka strain had tropism for human cell types similar to that of wild-type VZV. T lymphocytes released infectious VZV, which is a novel and important observation about the replication of this otherwise highly cell associated virus. VZV-infected skin implants exhibited microscopic epidermal lesions that were indistinguishable histologically from the characteristic lesions of varicella. These experiments demonstrate a unique tropism of VZV for human T lymphocytes, explaining its capacity to cause viremia in natural disease, and demonstrate the value of the SCID-hu model for studies of VZV pathogenesis.

Animals↗
PubMed1995

Type 1-like helper T cell lines responsive to autologous peripheral blood monocytes established from two patients with sarcoidosis.

In the present study, T cell lines, designated TU/BAL and KC/LN, were established from bronchoalveolar lavage (BAL) fluid and an affected lymph node, respectively, obtained from patients with active sarcoidosis by cultivating in the presence of IL-2. These cell lines produced IL-2 and proliferated by stimulation with the patient's own peripheral blood mononuclear cells treated with mitomycin C, while three other T cell lines established from ConA-stimulated BAL cells of patients with non-sarcoid lung diseases did not show any proliferative responses. The proliferation was mediated by IL-2, because anti-IL-2R alpha-chain monoclonal antibody (mAb) inhibited this response in a dose-dependent fashion. The adherent cell was a main stimulator of the proliferation. Both CD4 and HLA-DR appeared to be involved, because mAbs against these molecules inhibited this response. These results suggest that T cells obtained from sarcoid patients respond to a certain unknown antigen associated with HLA-DR or some self antigen expressed on the monocytes. Furthermore, both TU/BAL and KN/LN represented a profile of Th1-like cells: they secreted IL-2 and IFN-gamma, but not IL-4, IL-5 and IL-6, when stimulated with PHA in the presence or absence of 12-O-tetradecanoylphorbol-13-acetate. Thus, Th1-like cells activated by some unknown antigen(s) might play roles in the pathogenesis of sarcoidosis.

Adult↗
PubMed1995

[Liver herniation simulating a benign lung tumor].

A 49-year-old woman complained of coughing and sputum production a mass shadow was seen in the right lower lung field on a chest radiography. The shadow was first suspected to represent a benign lung tumor, because of its clear margin and narrow pedicle. After detailed examination liver herniation was suspected, since the CT number of the tumor was similar to that of the liver. Liver herniation was finally confirmed by chest MRI, liver scintigraphy and angiography of the abdomen. Liver herniation should be differentiated from an intrathoracic mass in the right lower lung field.

Diagnosis, Differential↗
PubMed1994

Human cytomegalovirus latent infection of granulocyte-macrophage progenitors.

We have investigated the interaction of human cytomegalovirus (CMV) with cultured primary granulocyte-macrophage progenitors, a suspected natural site of viral latency, and have established conditions for latent infection and reactivation in this cell population. Progenitor cells from human fetal liver or bone marrow maintained a CD14+, CD15+, CD33+ cell surface phenotype during propagation in suspension culture. Exposure to human CMV did not reduce growth or alter the phenotype of these cells during a 4-week culture period. Viral replication was not detectable in these cells, although viral DNA, as measured by PCR analysis, persisted in a high proportion of cultured cells in the absence of delayed early (beta) gene expression. Viral gene expression was restricted such that only ie1 region transcripts were detected by PCR analysis of cDNA, and these transcripts were estimated to be present in no less than 2-5% of latently infected cells. Most of these transcripts remained unspliced, a result that strikingly contrasts with the splicing pattern normally seen during viral replication in permissive cells. Latent virus reactivated after prolonged, 16- to 21-day cocultivation of infected granulocyte-macrophage progenitors with permissive cells, results that support a role for the myelomonocytic cell population as a biological reservoir of latent human CMV and suggest that these cells may be the source of CMV DNA PCR-positive monocytes found in the peripheral blood of healthy carriers.

Antigens, CD↗
PubMed1994

Human hematolymphoid cells in SCID mice.

The severe combined immunodeficient C.B.-17 scid/scid (SCID) mouse has been widely used to study the normal processes of murine lymphoid differentiation. To create an in vivo model of the human hematolymphoid system, this mouse strain has been engrafted with human organ systems (the SCID-hu mouse) or with human peripheral blood mononuclear cells (the hu-PBL-SCID mouse). These mouse models have now been characterized and used to analyze human infectious diseases, hematopoiesis, malignancies and vaccines.

Animals↗