Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001486 (Adenovirus)
 3,125 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The majority of human solid tumors are likely to express protein epitopes which can act as targets for cytotoxic T cells, but these are frequently not effectively recognized. We tested whether the introduction of the costimulatory molecule B7-1 using a recombinant adenovirus (Ad-B7) can result in effective induction of epitope-specific immunity in two tumor models that express defined endogenous protein epitopes: D459, a fibroblast-derived cell line transfected with a human missense mutant p53 (C to Y at position 135), and P815, a mastocytoma expressing the endogenous tumor epitope P1A. Under the conditions studied, both of these tumors grow and kill their hosts without evidence of significant immune rejection. However, after transduction with the adenovirus containing B7-1, both of these tumors lose tumorigenicity and elicit specific cellular immunity to the mutant p53 epitope in D459 and P1A in P815. In addition, animals exposed to B7-transduced tumor cells were protected from subsequent challenge with nontransduced tumor. Adenovirus has distinct advantages for this approach, as it has high infectivity not requiring in vitro culture, low lytic potential, and transient expression of sufficient duration for immunologic effectiveness but without significant concern over permanent genetic modification. We conclude that transduction of tumor cells with Ad-B7 can increase the immunogenicity of endogenous protein epitopes and may represent a practical therapeutic approach to system human cancers.
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PMID:Increased immunogenicity of tumors bearing mutant p53 and P1A epitopes after transduction of B7-1 via recombinant adenovirus. 885 48

Adenovirus (AdV)-mediated gene expression of immune stimulators represents a valuable in vivo approach for gene therapy of human cancer. The expression level of the therapeutic gene is of crucial importance for the efficacy of this type of treatment. Entry of AdV is dependent on the primary adenovirus receptor CAR and the secondary AdV receptor identified earlier to be a member of the integrin family of surface molecules. We have analyzed 14 different human melanoma cell cultures from different stages together with one melanoma cell line for their AdV-mediated transduction and expression efficiency. Recombinant viruses at various concentrations were used for expression of the B7-1 costimulatory molecule under the control of different promoters and the expression levels of B7-1 were analyzed by flow cytometry. AdV-mediated IL-12 expression was measured using a commercial ELISA. Levels of transgene expression were compared with the expression levels of HCAR, the alpha(v)beta3 and alpha(v)beta5 integrins, and HLA class I. In 4 of 14 cell cultures tested, the presence of the primary virus receptor CAR was associated with the high transduction efficiency phenotype when using the B7-1- and IL-12-expressing viruses at a relatively low multiplicity of infection (MOI) of 50. Immunohistochemistry on cryosections from the original biopsies yielded a strong signal specific for CAR. In contrast, cell cultures expressing low or undetectable levels of CAR needed a 20- to 40-fold higher viral input to show comparable expression level of B7-1 or IL-12. Expression levels of the transgenes hardly varied when using different promoters and no association was observed with the presence or absence of HLA class I molecules or with the expression levels of integrins.
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PMID:The presence of human coxsackievirus and adenovirus receptor is associated with efficient adenovirus-mediated transgene expression in human melanoma cell cultures. 982 35