Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD40 has been shown to play an important role in the regulation of B cell survival, proliferation and Ig class switching. The natural partner for CD40 is CD40 ligand, gp 39, which is transiently expressed on activated T cells. In vitro, CD40 ligation leads to polyclonal B cell proliferation and, in the presence of appropriate cytokines, to the secretion of Ig of various isotypes. In the present study we show that naive B cells cultured in vitro on CD40L-transfected mouse fibroblasts in the presence of two different soluble antigens (beta-galactosidase and phenyloxazolone coupled to ovalbumin) can be specifically immunized as shown by direct single cell Elispot assays or after establishment of B cell hybridomas. However, under the conditions of in vitro immunization used, all hybridomas analysed produced specific IgM antibodies only and we failed to detect cells that had switched to other isotypes. The data suggests that CD40 ligation can be used for efficient in vitro immunization against soluble antigens for IgM production but that CD40 signals even in conjunction with cytokines are insufficient to induce high rate switching.
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PMID:In vitro immunization of naive mouse B cells: establishment of IgM secreting hybridomas specific for souble protein or hapten from B cells cultured on CD40 ligand transfected mouse fibroblasts. 867 20

Skeletal muscle is an attractive target for somatic gene transfer of both acquired and inherited disorders. Direct injection of adenoviral vectors in the skeletal muscle leads to recombinant gene expression in a large number of muscle fibers. Transgene expression has been transient in most organs and associated with substantial inflammation when experiments are performed in adult immune competent mice. In this report, we utilize a variety of in vivo and in vitro models of T and B cell function to characterize the nature of the immune response to adenoviral vectors injected into murine skeletal muscle. Cellular immunity dependent on CD4+ and CD8+ T cells contributes to the loss of recombinant gene expression and the development of localized inflammation. Antigen specific activation of T cells occurs to both viral proteins and the reporter gene beta-galactosidase. Systemic levels of neutralizing antibody to the capsid proteins of the vector are also generated. Destructive immune responses responsible for loss of transgene expression are largely directed against beta-galactosidase in that transgene expression was stable when beta-galactosidase was eliminated as a neoantigen in mice transgenic for lacZ. A strategy to prevent the cellular and humoral immunity to this therapy was developed based on transiently ablating CD4+ T cell activation at the time of vector delivery. Encouraging results were obtained when vector was administered with one of several immune modulating agents including cyclophosphamide, mAb to CD4+ cells, and mAb to CD40 ligand. These studies indicate that cellular and humoral immune responses are elicited in the context of gene therapy directed to skeletal muscle with adenoviral vectors. Transient ablation of CD4+ T cell activation prevents the effects responses of the CD8+ T and B cells.
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PMID:Immunology of gene therapy with adenoviral vectors in mouse skeletal muscle. 892 97

We evaluated the efficiency of adenovirus-mediated gene transfer into normal and malignant human hematopoietic cells. An E-1 and E-3 deleted, replication-defective recombinant Ad.RSV beta gal vector was used and the transduction efficiency was studied at a multiplicity of infection of 13 p.f.u. per cell. Approximately 40-50% of normal monocytes were transduced, whereas purified normal resting T cells and B cells were resistant to infection. We showed that 50-80% of primary chronic myeloid leukemia cells (CML, n = 12) were efficiently transduced in contrast to CML, successful transduction of resting primary chronic B lymphocytic leukemia cells required appropriate preactivation of targeted cells. A novel protocol for the efficient transduction of adenovirus into B-CLL cells was presented. We showed that anti-CD40 mAb or CD40 ligand acts in synergy with rhIL-4 to enable the transduction of approximately 50-75% of B-CLL cells (B-CLL, n = 6). Expression of beta-galactosidase in transduced CML cells and B-CLL cells was detected for at least 15 days after transduction. The present studies underline the utility of adenovirus vectors for the construction of cytokine gene-modified tumor vaccines for the treatment of hematopoietic malignancies such as CML and B-CLL.
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PMID:Efficient adenovirus-mediated gene transduction of normal and leukemic hematopoietic cells. 941 16

The anti-CD40 ligand antibody MR-1, and macrophage-depleting liposomes were tested for their ability as transient immunosuppressive agents to: (1) prolong transgene expression; and (2) permit redosing after recombinant adenovirus infusion of mice. To test for effect on transgene duration, mice were infused with recombinant adenovirus coding for human factor IX (AdFIX), and plasma FIX levels monitored over time. Treatment with either agent significantly prolonged transgene expression. Persistence was accompanied by inhibition of anti-adenovirus (anti-Ad) IgG, and decreased IL-10 and IFN-gamma production from splenic lymphocytes re-exposed to virus particles in vitro. To test for effect on redosing, mice were given a primary infusion of recombinant adenovirus coding for bacterial beta-galactosidase (Ad beta gal), followed by secondary and tertiary infusions of AdFIX on days 24 and 63. Mice that had received MR-1 had low to undetectable anti-Ad on day 24, and efficient transduction occurred. Furthermore, FIX levels endured in these mice, with 40% retention of FIX on day 63, in contrast to rapid loss in naive controls. On day 63, the continuance of negligible anti-Ad levels correlated with successful tertiary transduction. These results suggest that both macrophage depletion and CD40 ligand blockade inhibit immune responses to recombinant adenovirus to slow decline of transgene expression, while only CD40 ligand blockade inhibits anti-Ad antibody generation sufficiently to allow redosing to the liver.
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PMID:Effects of macrophage depletion and anti-CD40 ligand on transgene expression and redosing with recombinant adenovirus. 961 66

Recombinant adenovirus vectors have been used to transfer genes to the lungs in animal models, but the extent and duration of primary transgene expression and the ability to achieve expression after repeated vector administration have been limited by the development of antigen-specific immunity to the vector and, in some cases, to vector-transduced foreign proteins. To determine if focused modulation of the immune response could overcome some of these limitations, costimulatory interactions between T cells and B cells/antigen-presenting cells were transiently blocked around the time of vector administration. Systemic treatment at the time of primary-vector administration with a monoclonal antibody (MR1) against murine CD40 ligand, combined with recombinant murine CTLA4Ig and intratracheal coadministration of an adenovirus vector transducing the expression of murine CTLA4Ig, prolonged adenovirus-transduced beta-galactosidase expression in the airways for up to 28 days and resulted in persistent alveolar expression for >90 days (the duration of the experiment). Consistent with these results, this treatment regimen reduced local inflammation and markedly reduced the T-cell and T-cell-dependent antibody response to the vector. A secondary adenovirus vector, administered >90 days after the last systemic dose of MR1 and muCTLA4Ig, resulted in alkaline phosphatase expression at levels comparable to those seen with primary-vector administration. Expression of the secondary transgene persisted in the alveoli (but not in the airways) for up to 24 days (the longest period of observation) at levels similar to those observed on days 3 to 4. These results indicate that transient inhibition of costimulatory molecule interactions substantially enhanced gene transfer to the alveoli but was much less effective in the airways. This suggests that there are differences in the efficiency or nature of mechanisms limiting transgene expression in the airways and in the alveoli.
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PMID:Transient inhibition of CD28 and CD40 ligand interactions prolongs adenovirus-mediated transgene expression in the lung and facilitates expression after secondary vector administration. 969 51

CD40/CD40 ligand interactions have a central role in the induction of both humoral and cellular immunity. In this study, we examined whether a plasmid expressing CD40 ligand/trimer (CD40LT) could enhance immune responses in vivo. BALB/c mice were injected with plasmid expressing beta-galactosidase DNA with or without CD40LT DNA or IL-12 DNA, and immune responses were assessed. Mice vaccinated with beta-gal DNA plus CD40LT DNA or IL-12 DNA had a striking increase in Ag-specific production of IFN-gamma, cytolytic T cell activity, and IgG2a Ab. The mechanism by which CD40LT DNA enhanced these responses was further assessed by treating vaccinated mice with anti-IL-12 mAb or CTLA-4 Ig (CTLA4Ig). Production of IFN-gamma and CTL activity was abrogated by these treatments, suggesting that CD40LT DNA was mediating its effects on IFN-gamma and CTL activity through induction of IL-12 and enhancement of B7 expression, respectively. Physiologic relevance for the ability of CD40LT DNA to enhance immune responses by the aforementioned pathways was shown in two in vivo models. First, with regard to CTL activity, mice vaccinated with CD40LT DNA did not develop metastatic tumor following challenge with lethal dose of tumor. Moreover, in a mouse model requiring IL-12-dependent production of IFN-gamma, mice vaccinated with soluble Leishmania Ag and CD40LT DNA were able to control infection with Leishmania major. These data suggest that CD40LT DNA could be a useful vaccine adjuvant for diseases requiring cellular and/or humoral immunity.
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PMID:CD40 ligand/trimer DNA enhances both humoral and cellular immune responses and induces protective immunity to infectious and tumor challenge. 979 83

CD40 is thought to play a central role in T cell-dependent humoral responses through two distinct mechanisms. CD4+ T helper cells are activated via CD40-dependent Ag presentation in which CD80/CD86 provides costimulation through CD28. In addition, engagement of CD40 on B cells provides a direct pathway for activation of humoral responses. We used a model of adenovirus-mediated gene transfer of beta-galactosidase (lacZ) into murine lung to evaluate the specific CD40-dependent pathways required for humoral immunity at mucosal surfaces of the lung. Animals deficient in CD40L failed to develop T and B cell responses to vector. Activation of Th2 cells, which normally requires CD40-dependent stimulation of APCs, was selectively reconstituted in CD40 ligand-deficient mice by systemic administration of an Ab that is agonistic to CD28. Surprisingly, this resulted in the development of a functional humoral response to vector as evidenced by formation of germinal centers and production of antiadenovirus IgG1 and IgA that neutralized and prevented effective readministration of vector. The CD28-dependent B cell response required CD4+ T cells and was mediated via IL-4. These studies indicate that CD40 signals to the B cells are not necessary for CD4+ Th2 cell-dependent humoral responses to be generated.
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PMID:Th2-dependent B cell responses in the absence of CD40-CD40 ligand interactions. 1060 18

Recombinant adeno-associated virus type 2 (rAAV) is being explored as a vector for gene therapy because of its broad host range, good safety profile, and persistent transgene expression in vivo. However, accumulating evidence indicates that administration of AAV vector may initiate a detectable cellular and humoral immune response to its transduced neo-antigen in vivo. To elucidate the cellular basis of the AAV-mediated immune response, C57BL/6 mouse bone marrow-derived immature and mature dendritic cells (DCs) were infected with AAV encoding beta-galactosidase (AAV-lacZ) and adoptively transferred into mice that had received an intramuscular injection of AAV-lacZ 10 days earlier. Unexpectedly, C57BL/6 mice but not CD40 ligand-deficient (CD40L(-/-)) mice adoptively transferred with AAV-lacZ-infected immature DCs developed a beta-galactosidase-specific cytotoxic T-lymphocyte (CTL) response that markedly diminished AAV-lacZ-transduced gene expression in muscle fibers. In contrast, adoptive transfer of AAV-lacZ-infected mature DCs failed to elicit a similar CTL response in vivo. Our findings indicate, for the first time, that immature DCs may be able to elicit a CD40L-dependent T-cell immunity to markedly diminish AAV-lacZ transduced gene expression in vivo when a sufficient number of DCs capturing rAAV vector and/or its transduced gene products is recruited.
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PMID:CD40 ligand-dependent activation of cytotoxic T lymphocytes by adeno-associated virus vectors in vivo: role of immature dendritic cells. 1093 9