Journal of virology
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Journal of virology · Sep 1999
CD4-Chemokine receptor hybrids in human immunodeficiency virus type 1 infection.
Most human immunodeficiency virus (HIV) strains require both CD4 and a chemokine receptor for entry into a host cell. In order to analyze how the HIV-1 envelope glycoprotein interacts with these cellular molecules, we constructed single-molecule hybrids of CD4 and chemokine receptors and expressed these constructs in the mink cell line Mv-1-lu. The two N-terminal (2D) or all four (4D) extracellular domains of CD4 were linked to the N terminus of the chemokine receptor CXCR4. ⋯ Thus SDF-1, but not the smaller molecule AMD3100, may interfere at multiple points with the binding of the surface unit (SU)-CD4 complex to CXCR4, a mechanism that the covalent linkage of CD4 to CXCR4 impedes. Although the CD4-CXCR4 hybrids yielded enhanced SU interactions with the chemokine receptor moiety, this did not overcome the specific coreceptor requirement of different HIV-1 strains: the X4 virus HIV-1(LAI) and the X4R5 virus HIV-1(89. 6), unlike the R5 strain HIV-1(SF162), infected Mv-1-lu cells expressing the CD4(2D)CXCR4 hybrid, but none could use hybrids of CD4 and the chemokine receptor CCR2b, CCR5, or CXCR2. Thus single-molecule hybrid constructs that mimic receptor-coreceptor complexes can be used to dissect coreceptor function and its inhibition.
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Journal of virology · Nov 1998
Comparative StudyFactors influencing adeno-associated virus-mediated gene transfer to human cystic fibrosis airway epithelial cells: comparison with adenovirus vectors.
Adeno-associated virus (AAV) vectors appear promising for use in gene therapy in cystic fibrosis (CF) patients, yet many features of AAV-mediated gene transfer to airway epithelial cells are not well understood. We compared the transduction efficiencies of AAV vectors and adenovirus (Ad) vectors in immortalized cell lines from CF patients and in nasal epithelial primary cultures from normal humans and CF patients. Similar dose-dependent relationships between the vector multiplicities of infection and the efficiencies of lacZ gene transfer were observed. ⋯ Expression of Ad E4 open reading frame 6 or addition of either hydroxyurea or camptothecin resulted in increased AAV transduction, as previously demonstrated for nonairway cells (albeit to lower final levels), suggesting that second-strand synthesis may not be the sole cause of inefficient transduction. Finally, the efficiency of AAV-mediated ex vivo gene transfer to lung cells was similar to that previously described for Ad vectors in that transduction was limited to regions of epithelial injury and preferentially targeted basal-like cells. These studies address the primary factors influencing rAAV infection of human airway cells and should impact successful gene delivery in CF patients.
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Journal of virology · Apr 1998
Characterization of Ebola virus entry by using pseudotyped viruses: identification of receptor-deficient cell lines.
Studies analyzing Ebola virus replication have been severely hampered by the extreme pathogenicity of this virus. To permit analysis of the host range and function of the Ebola virus glycoprotein (Ebo-GP), we have developed a system for pseudotyping these glycoproteins into murine leukemia virus (MLV). ⋯ Notably, all lymphoid cell lines tested were completely resistant to infection; we speculate that this is due to the absence of a cellular receptor for Ebo-GP on B and T cells. The generation of high-titer MLV(Ebola) pseudotypes will be useful for the analysis of immune responses to Ebola virus infection, development of neutralizing antibodies, analysis of glycoprotein function, and isolation of the cellular receptor(s) for the Ebola virus.
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Journal of virology · Apr 1997
Inducible nitric oxide synthase in Theiler's murine encephalomyelitis virus infection.
We investigated the role of inducible nitric oxide synthase (iNOS) in Theiler's murine encephalomyelitis virus (TMEV) infection of susceptible (SJL) and resistant (C57BL/6 [B6]) strains of mice. TMEV is an excellent model of virus-induced demyelinating disease, such as multiple sclerosis (MS). Previous studies of others have suggested that NO may play a role in the pathogenesis of demyelinating disease. ⋯ Weak iNOS staining was also observed in cells of the monocyte/macrophage lineage in areas of parenchymal inflammation and necrosis (mesencephalon) and in leptomeningeal and white matter perivascular infiltrates of the spinal cord. Rod-shaped microglia-like cells and foamy macrophages (myelin-laden) were iNOS negative. These results suggest that NO does not play a direct role in the late phase of demyelinating disease in TMEV-infected mice.
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Journal of virology · Feb 1995
Immunopathogenic role of T-cell subsets in Borna disease virus-induced progressive encephalitis.
Borna disease is an immunopathological virus-induced encephalopathy comprising severe inflammation and degenerative brain cell lesions which results in organ atrophy and chronic debility in rats. CD4+ and CD8+ T cells have been reported to be involved in the development of this disease of the central nervous system. A virus-specific homogeneous T-cell line, established in vitro after immunization of rats with the recombinant 24-kDa virus-specific protein, showed antigen-specific proliferation in the presence of the 24-kDa but not the 38-kDa Borna disease virus-specific protein, another major virus-specific antigen. ⋯ However, recipient rats treated with antibodies against CD8+ T cells developed neither encephalitis nor disease. Therefore, CD4+ T cells appear to accumulate in the brain and cause perivascular inflammatory lesions which alone obviously do not cause disease. In contrast, the presence of CD8+ cells apparently directly correlates with the development of neurological symptoms.