Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mice with congenital severe combined immunodeficiency disease (SCID) failed to mount either a T cell-independent IgM or T cell-dependent IgG anti-vesicular stomatitis virus (VSV) Indiana (IND) response. They did not generate cytotoxic T cells against lymphocytic choriomeningitis virus (LCMV) or vaccinia virus, but exhibited NK cell-like activities. When SCID mice were given bone marrow from syngeneic BALB/c (H-2d) nu/nu mice, all immune responses were expressed at control levels. If SCID mice were reconstituted with allogeneic H-2b C57BL/6 nu/nu bone marrow, the following primary anti-viral immune responses were measured. T-independent IgM anti-VSV-IND were normal, but T-dependent IgG anti-VSV-IND responses were absent. Cytotoxic T cell responses to LCMV and vaccinia virus were within normal ranges, were donor cell mediated, and were specific exclusively for the recipient SCID H-2d type. Since antigen presentation by spleen cells was functional in these chimaeras, the presented results indicate that (a) thymic selection of T cell restriction is strict; and (b) the type of T help necessary for B cells depends upon H-2-restricted contact between T and B cells, whereas, such contact-dependent help is not mandatory for the induction of virus-specific cytotoxic T cells.
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PMID:Thymic selection of H-2-incompatible bone marrow cells in SCID mice. Differences in T help for induction of B cell IgG responses versus cytotoxic T cells. 297 54

After allogeneic bone marrow transplantation certain patterns of infectious complications emerge that follow the clinical course, are correlated to the immunobiology of transplantation and are almost predictable in their character and expression. The preparative regimen, designed to generate complete aplasia, will be associated with severe and sometimes life-threatening bacterial infections, predominantly with Gram-negative organisms derived from bowel flora, but also Gram-positive skin saprophytes. In this early aplastic phase, life-threatening viral infections are less common, consisting mainly of herpes simplex and possibly Epstein-Barr stomatitis and BK papovavirus cystitis. Systemic infections with invasive filamentous fungi are rare and are seen only when the induced aplasia is markedly prolonged. Once early marrow recovery has been achieved, systemic infections will generally disappear unless acute graft-vs.-host disease develops. This complication, which will lead to the breakdown of natural barriers such as skin and gastrointestinal epithelium and the marked impairment of all systemic defense mechanisms, can cause polymicrobial infections as well as set the stage for life-threatening viral infections. Such opportunistic viral infections, leading to either interstitial pneumonia or hemorrhagic gastroenteritis, are the major threat in the early recovery phase after engraftment has taken place. Usually caused by cytomegalovirus and rotavirus, respectively, these infections are the primary expression of the severe combined immunodeficiency post transplant, statistically associated with the presence of acute graft-vs.-host disease and amenable to immunologic manipulations. With the recovery of cellular and humoral immune function derived from transplanted donor lymphoid cells, the third phase of infectious complications is reached, covering 3 months to 2 years post grafting.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Infections and immunodeficiency in bone marrow transplantation. 304 57

The size of the Ab repertoire has been estimated to comprise theoretically somewhere between > 10(10) and approximately 10(4) specificities, dependent on the criteria used. In an attempt to estimate the anti-viral protective Ab repertoire of the mouse the B cell and Ab-forming cell (AFC) frequencies and protective neutralizing Ab levels during the course of an infection with vesicular stomatitis virus (VSV) were analyzed. Determination of AFC frequencies, limiting dilution assays, and adoptive transfer experiments to SCID mice revealed that during the acute phase (day 8) of the immune response, more than 50% of all IgG2a-producing AFCs were specific for VSV, most of them recognizing the neutralizing determinant. In a later phase (days 21 or 50), 10 to 20 times fewer VSV-specific AFCs were present, corresponding to a frequency of approximately 1:10(4) spleen cells. Finally, in a protection assay in SCID mice, adoptively transferred protective Ab concentrations were found to be approximately 1 to 10 micrograms Ab/ml mouse serum. Because during the memory phase of the anti-VSV response usually 10(4) AFC/mouse are engaged to maintain a high level of memory IgG against the neutralizing determinant on VSV and if one assumes a total number of about 10(6) AFCs/mouse, these data suggest a rather limited neutralizing anti-viral protective memory-AFC repertoire of 10(2) to 10(4) different specificities.
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PMID:How many specific B cells are needed to protect against a virus? 751 89

Gene therapy strategies for humans have been limited by low transduction efficiencies and poor expression of retroviral vectors in differentiated progeny cells carrying the transduced vector. Here we describe a strategy utilizing a cell surface reporter gene, murine thy-1.2, selectable by fluorescence-activated cell sorting (FACS), to achieve higher gene marking efficiencies. Human CD34-positive cells were transduced by a murine retroviral vector bearing the thy-1.2 marker and pseudotyped with vesicular stomatitis virus G protein, followed by FACS to enrich for CD34-positive cells that express Thy-1.2 on the cell surface. Gene marking and expression after differentiation into thymocytes were assessed in a SCID-hu Thy/Liv mouse model for human lymphoid progenitor cell gene therapy. We found that virtually all of the differentiated T-cell progeny were marked with vector sequences. It is of particular importance that reconstitution with the selected cells resulted in expression of Thy-1.2 in up to 71% of donor-derived thymocytes. It is of note that the donor-derived thymocytes that did not express Thy-1.2 still harbored vector thy-1.2 sequences, suggesting repression of transgene expression in some cells during progenitor cell differentiation into thymocytes. These studies provide a proof of concept for efficient expression of transgenes through T-lymphoid differentiation and a potential basis for utilizing similar strategies in human gene therapy clinical trials.
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PMID:High-efficiency transduction of human lymphoid progenitor cells and expression in differentiated T cells. 899 65

Gene transfer into haematopoietic stem cells (HSC) has been investigated for treatment of genetic disorders, conferral of chemotherapy resistance and insertion of genes to inhibit HIV-1 replication. Methods have been available for almost a decade to transduce murine HSC using high-titre retroviral vectors and stimulation of HSC proliferation with cytokines such as IL-3 and IL-6. Unfortunately, attempts to replicate the high efficiency of gene transfer using canine or simian gene transfer/bone marrow transplantation models have consistently shown that only a small fraction (0.1-1%) of reconstituting HSC are transduced using protocols similar to those which are successful in murine models. Initial clinical trials using retroviral-mediated gene transfer into human HSC also produced minimal transduction frequencies. The dicotomous results may reflect differences in the cell cycle kinetics of murine HSC versus those of larger mammals or the density of receptors for the retroviral vectors on the cells. Attempts to increase the fraction of HSC which are in active cell cycle, a prerequisite for retroviral-mediated transduction, have used either combinations of recombinant cytokines, culture on marrow stromal layers, or alternative sources for HSC, such as mobilized peripheral blood stem cells or umbilical cord blood. Other efforts have used retroviral vectors packaged with either the Gibbon Ape Leukemia virus envelope or the Vesicular Stomatitis Virus G protein. To date, none of these methods has produced a significantly increased frequency of long-term reconstituting HSC. Results using adeno-associated virus (AAV)-based vectors for HSC transduction have been conflicting, with the stable persistence of non-integrated virus particles making interpretation of results difficult using in vitro assays. Therefore, clinical trials may best be directed toward disorders that may benefit from a small fraction of genetically corrected HSC. These would include disorders where progeny of corrected HSC would be expected to have a selective survival advantage (e.g. SCID, WAS, HIV, chemoresistance) or where a small fraction of corrected cells can have a direct clinical benefit (e.g. CGD, MPS). Further basic research into HSC biology and gene delivery vectors must continue for wider application, such as haemoglobinopathies and some lysosomal storage diseases.
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PMID:Gene therapy for haematopoietic and lymphoid disorders. 902 Sep 37

To define the role of T cells and B cells in resistance to vesicular stomatitis virus (VSV) infection, knockout mice with different specific immune defects on an identical background were infected i.v. and the outcome of infection was compared; in this way a more complete picture of the relative importance of various host defence mechanisms could be obtained. Compared to T and B cell-deficient SCID mice which all succumbed from encephalitis within 5-9 days of infection, T cell-deficient nude mice generally lived longer, but within a period of approximately 1 month after challenge all died. In contrast, B cell-deficient mice were highly susceptible even to low doses of virus and mortality could be prevented by transfer of naive B cells prior to challenge as well as by immune serum given after challenge. Analysis of MHC class I- and class II-deficient mice revealed that CD8+ T cells could exert some antiviral activity, but CD4+ T cells sufficed for survival and were required for optimal resistance. Consistent with this it was found that in nude mice a lethal outcome could be prevented by transfer of CD8-depleted cells from B cell-deficient mice. Thus our results clearly demonstrate that while antibodies are pivotal for survival in the early phase of VSV infection, T cells are required for long-term survival, with CD4+ T cells being more effective in controlling this infection than CD8+ T cells.
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PMID:Cooperation of B cells and T cells is required for survival of mice infected with vesicular stomatitis virus. 941 36

Murine retroviral vectors have the potential to mediate stable gene transfer into hematopoietic progenitor cells. A known drawback to the use of these vectors is that transduction can only take place in cells actively progressing through the cell cycle. Thrombopoietin, the c-mpl ligand, is known to support division of hematopoietic precursors of primitive origin. Polyethylene glycol (PEG)-conjugated recombinant human megakaryocyte growth and development factor (MGDF) is a polypeptide related to thrombopoietin that stimulates megakaryocyte production. To investigate whether MGDF would also induce stem cell division and support retroviral transduction of CD34+ cells, we compared the effects of MGDF, stem cell factor (SCF), interleukin-3 (IL-3), and IL-6, alone or in combination, using amphotropic and vesicular stomatitis virus (VSV-G) pseudotyped murine retroviral vectors. Similar transduction efficiency was observed when CD34+ cells were transduced in the presence of SCF and MGDF as compared to SCF, IL-3, and IL-6. Using the SCID-hu mouse model of thymopoiesis, we investigated whether CD34+ cells transduced in the presence of these cytokines could reconstitute irradiated thymic implants, and whether vector sequences were present in mature thymocytes. At early timepoints, no significant differences were observed on engraftment of donor progenitors incubated with each cytokine combination. However, a significant difference in the percentage of donor derived CD4+/CD8+ immature thymocytes was observed 9 weeks after implantation of CD34+ cells exposed to the combination of SCF and MGDF as compared to SCF, IL-3, and IL-6 (p = 0.04), indicating that MGDF/SCF better supported the survival of thymocyte precursor cells. Approximately 4% of thymocytes in both cytokine groups harbored vector sequences. These studies provide evidence that MGDF and SCF in combination can mediate transduction of hematopoietic progenitors capable of contributing to long-term thymopoiesis. These results may have important applications for the implementation of gene therapy strategies in disorders affecting the T lymphoid system.
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PMID:Effects of megakaryocyte growth and development factor on survival and retroviral transduction of T lymphoid progenitor cells. 947 77

Retrovirus-mediated gene transfer into long-lived human pluripotent hematopoietic stem cells (HSCs) is a widely sought but elusive goal. A major problem is the quiescent nature of most HSCs, with the perceived requirement for ex vivo prestimulation in cytokines to induce stem cell cycling and allow stable gene integration. However, ex vivo culture may impair stem cell function, and could explain the disappointing clinical results in many current gene transfer trials. To address this possibility, we examined the ex vivo survival of nonobese diabetic/severe combined immune-deficient (NOD/SCID) repopulating cells (SRCs) over 3 days. After 1 day of culture, the SRC number and proliferation declined twofold, and was further reduced by day 3; self-renewal was only detectable in noncultured cells. To determine if the period of ex vivo culture could be shortened, we used a vesicular stomatitis virus G protein (VSV-G) pseudotyped retrovirus vector that was concentrated to high titer. The results showed that gene transfer rates were similar without or with 48 hours prestimulation. Thus, the use of high-titer VSV-G pseudotyped retrovirus may minimize the loss of HSCs during culture, because efficient gene transfer can be obtained without the need for extended ex vivo culture.
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PMID:One-day ex vivo culture allows effective gene transfer into human nonobese diabetic/severe combined immune-deficient repopulating cells using high-titer vesicular stomatitis virus G protein pseudotyped retrovirus. 1009 Sep 30

The major limitations of Moloney murine leukemia virus (MoMLV)-based vectors for human stem cell applications, particularly those requiring bone marrow (BM) stem cells, include their requirement for mitosis and retroviral receptor expression. New vectors based upon lentiviruses such as HIV-1 exhibit properties that may circumvent these problems. We report that novel third-generation, self-inactivating lentiviral vectors, expressing enhanced green fluorescent protein (EGFP) and pseudotyped with vesicular stomatitis virus G glycoprotein (VSV-G), can efficiently transduce primitive human repopulating cells derived from human BM and cord blood (CB) tested by the SCID-repopulating cell (SRC) assay. Highly purified CD34+ CD38- CB or BM cells were efficiently transduced (4-69%) and stably expressed in EGFP for 40 days in culture following infection for only 24 h without fibronectin, polybrene, or cytokines. Nonobese diabetic/severe combined immune-deficient (NOD/SCID) mice transplanted with transduced cells from either CB or BM donors were well engrafted, demonstrating maintenance of SRC during the infection procedure. Serially obtained femoral BM samples indicated that the proportion of EGFP+ cells within both myeloid and lymphoid lineages was maintained or even increased over time, averaging 42.3 +/- 6.6% for BM donors and 23.3 +/- 7.2% for CB at 12 weeks. Thus, the third-generation lentivectors readily transduce human CB and BM stem cells, under minimal conditions of ex vivo culture, where MoMLV-based vectors are ineffective. Since CB is inappropriate for most therapeutic applications, the efficient maintenance and transduction of BM-derived SRC during the short infection procedure are notable advantages of lentivectors.
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PMID:Transduction of human CD34+ CD38- bone marrow and cord blood-derived SCID-repopulating cells with third-generation lentiviral vectors. 1093 81

The low levels of transduction of human hematopoietic stem cells (HSCs) with Moloney murine leukemia virus (MLV) vectors have been an obstacle to gene therapy for hematopoietic diseases. It has been demonstrated that lentivirus vectors are more efficient than MLV vectors at transducing nondividing cell lines as well as human CD34(+) cells and severe combined immunodeficiency disease repopulating cells. We compared transduction of cell lines and Lin(-) bone marrow cells, using a vesicular stomatitis virus G (VSV-G)-pseudotyped lentivirus or MLV vectors carrying a green fluorescent protein marker gene. As predicted, the lentivirus vector was more efficient at transducing mouse and human growth-inhibited cell lines. The transduction of mouse HSC by lentivirus vectors was compared directly to MLV vectors in a co-transduction assay. In this assay, transduction by ecotropic MLV is a positive internal control for downstream steps in retrovirus transduction, including cell division. Both the VSV-G lentivirus and MLV vectors transduced mouse HSCs maintained in cytokine-free medium at very low frequency, as did the ecotropic control. The lentivirus vector and the MLV vector were equally efficient at transducing bone marrow HSCs cultured in interleukin 3 (IL-3), IL-6, and stem cell factor for 96 hours. In conclusion, although lentivirus vectors are able to transduce growth-inhibited cell lines, the cell cycle status of HSCs render them resistant to lentivirus-mediated transduction, and it is hypothesized that entry into cycle, not necessarily division, may be a requirement for efficient lentivirus-mediated transduction.
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PMID:Lentivirus-based vectors transduce mouse hematopoietic stem cells with similar efficiency to moloney murine leukemia virus-based vectors. 1107 32


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