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Articles 1411 - 1440 of 1476

Full-Text Articles in Microbiology

Two Factors That Bind To Highly Conserved Sequences In Mammalian Type C Retroviral Enhancers., Nancy R. Manley, Mary M. O'Connell, Wanwen Sun, Nancy A. Speck, Nancy Hopkins Apr 1993

Two Factors That Bind To Highly Conserved Sequences In Mammalian Type C Retroviral Enhancers., Nancy R. Manley, Mary M. O'Connell, Wanwen Sun, Nancy A. Speck, Nancy Hopkins

Dartmouth Scholarship

The transcriptional enhancers of the Moloney and Friend murine leukemia viruses (MLV) are important determinants of viral pathogenicity. We used electrophoretic mobility shift and methylation interference assays to study nuclear factors which bind to a region of these enhancers whose sequence is identical between Moloney and Friend viruses and particularly highly conserved among 35 mammalian type C retroviruses whose enhancer sequences have been aligned (E. Golemis, N. A. Speck, and N. Hopkins, J. Virol. 64:534-542, 1990). Previous studies identified sites for the leukemia virus factor b (LVb) and core proteins in this region (N. A. Speck and D. Baltimore, Mol. …

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Characterization Of A Protein That Binds Multiple Sequences In Mammalian Type C Retrovirus Enhancers., Wanwen Sun, Mary M. O'Connell, Nancy A. Speck Apr 1993

Characterization Of A Protein That Binds Multiple Sequences In Mammalian Type C Retrovirus Enhancers., Wanwen Sun, Mary M. O'Connell, Nancy A. Speck

Dartmouth Scholarship

Mammalian type C retrovirus enhancer factor 1 (MCREF-1) is a nuclear protein that binds several directly repeated sequences (CNGGN6CNGG) in the Moloney and Friend murine leukemia virus (MLV) enhancers (N. R. Manley, M. O'Connell, W. Sun, N. A. Speck, and N. Hopkins, J. Virol. 67:1967-1975, 1993). In this paper, we describe the partial purification of MCREF-1 from calf thymus nuclei and further characterize the binding properties of MCREF-1. MCREF-1 binds four sites in the Moloney MLV enhancer and three sites in the Friend MLV enhancer. Ethylation interference analysis suggests that the MCREF-1 binding site spans two adjacent minor grooves of …

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Book Review: The Baculovirus Expression System: A Laboratory Guide (1992) King, L. A. & Possee, R. D., David D. Dunigan Jan 1993

Book Review: The Baculovirus Expression System: A Laboratory Guide (1992) King, L. A. & Possee, R. D., David D. Dunigan

Nebraska Center for Virology: Faculty Publications

The power of molecular biology is unleashed with the ability to clone and sequence genes, and then express these genes in heterologous systems. This sets the stage for the full analysis of proteins that are otherwise difficult to isolate and/or purify, especially when present at very low copy number per cell or when isolated from relatively precious materials. Overexpression of protein is now possible in a number of systems including prokaryotes (e.g., E. coli) and various eukaryotes (yeast, insects, and plants). The issue then becomes, which system (1) most closely reflects the homologous expression with respect to posttranslational modifications, …

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Loss Of Infectivity By Progeny Virus From Alpha Interferon- Treated Human Immunodeficiency Virus Type 1-Infected T Cells Is Associated With Defective Assembly Of Envelope Gp120, Brian D. Hanson, Peter L. Nara, Radha K. Maheshwari, Girmel S. Sidhu, John G. Bernbaum, David Hoekzema, Monte S. Meltzer, Howard Gendelman Dec 1992

Loss Of Infectivity By Progeny Virus From Alpha Interferon- Treated Human Immunodeficiency Virus Type 1-Infected T Cells Is Associated With Defective Assembly Of Envelope Gp120, Brian D. Hanson, Peter L. Nara, Radha K. Maheshwari, Girmel S. Sidhu, John G. Bernbaum, David Hoekzema, Monte S. Meltzer, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Levels of human immunodeficiency virus (HIV) DNA, RNA, or p24 antigen and reverse transcriptase activity in T-cell cultures treated with 500 IU of recombinant alpha interferon (rIFNα) per ml were comparable to those in control cultures. Radioimmunoprecipitation analysis of proteins in lysates of IFN-treated T cells documented a marked accumulation of HlV proteins. Localization of gp120 by immunofluorescence showed a diffuse pattern in IFN-treated cells quite distinct from the ring pattern in untreated control cells. That large quantities of a120 in aberrant cell compartments might affect HlV morphogenesis was confirmed in infectivity studies: virions from IFN-treated cells were 100- to …

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Processing And Localization Of Dengue Virus Type 2 Polyprotein Precursor Ns3-Ns4a-Ns4b-Ns5, Luwen Zhang, P. Maruthi Mohan, R. Padmanabhan Dec 1992

Processing And Localization Of Dengue Virus Type 2 Polyprotein Precursor Ns3-Ns4a-Ns4b-Ns5, Luwen Zhang, P. Maruthi Mohan, R. Padmanabhan

Nebraska Center for Virology: Faculty Publications

Processing of dengue virus type 2 polyprotein precursor NS3-NS4A-NS4B-NS5 could be mediated by the catalytically active NS3 protease domain and NS2B in trans at the dibasic sites NS3-NS4A and NS4B-NS5. Subcellular localization of the unprocessed precursor NS3-NS4A-NS4B-NS5 showed that it was confined to a distinct subcellular organelle in the cytoplasm, which was distinct from the distribution of the mature NS5.

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Worldwide Prevalence Of Lentivirus Infection In Wild Feline Species: Epidemiologic And Phylogenetic Aspects, Robert A. Olmstead, Raymond Langley, Melody E. Roelke, Robert M. Goeken, Diane Adger-Johnson, Julie P. Goff, John P. Albert, Craig Packer, M. Karen Laurenson, Tim M. Caro, Lue Scheepers, David E. Wildt, Mitchell Bush, Janice S. Martenson, Stephen J. O'Brien Oct 1992

Worldwide Prevalence Of Lentivirus Infection In Wild Feline Species: Epidemiologic And Phylogenetic Aspects, Robert A. Olmstead, Raymond Langley, Melody E. Roelke, Robert M. Goeken, Diane Adger-Johnson, Julie P. Goff, John P. Albert, Craig Packer, M. Karen Laurenson, Tim M. Caro, Lue Scheepers, David E. Wildt, Mitchell Bush, Janice S. Martenson, Stephen J. O'Brien

Biology Faculty Articles

The natural occurrence of lentiviruses closely related to feline immunodeficiency virus (FIV) in nondomestic felid species is shown here to be worldwide. Cross-reactive antibodies to FIV were common in several free-ranging populations of large cats, including East African lions and cheetahs of the Serengeti ecosystem and in puma (also called cougar or mountain lion) populations throughout North America. Infectious puma lentivirus (PLV) was isolated from several Florida panthers, a severely endangered relict puma subspecies inhabiting the Big Cypress Swamp and Everglades ecosystems in southern Florida. Phylogenetic analysis of PLV genomic sequences from disparate geographic isolates revealed appreciable divergence from domestic …

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Identification And Characterization Of The Bovine Immunodeficiency-Like Virus Tat Gene, Zhen-Qian Liu, Deborah Sheridan, Charles Wood Aug 1992

Identification And Characterization Of The Bovine Immunodeficiency-Like Virus Tat Gene, Zhen-Qian Liu, Deborah Sheridan, Charles Wood

Nebraska Center for Virology: Faculty Publications

A cDNA clone of the bovine immunodeficiency-like virus (BW) trans-activator gene (tat) was identified and characterized. The tat cDNA clone was generated by splicing, and on the basis of sequence analysis, the Tat protein was found to be encoded entirely by the first exon. It is 103 amino acids in size and shares sequence homology with the human immunodeficiency virus (HW) Tat. The BIV tat clone can trans activate the BIV promoter effectively, as measured by the expression of the bacterial chloramphenicol acetyltransferase gene, when transfected into bovine cells. Besides activating the BIV promoter, the BIV Tat can also trans …

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Kinetic Characterization Of A Recombinant C-Terminal Mutant Of Reverse Transcriptase From The Human Immunodeficiency Virus, Thomas S. Heard Jul 1992

Kinetic Characterization Of A Recombinant C-Terminal Mutant Of Reverse Transcriptase From The Human Immunodeficiency Virus, Thomas S. Heard

Chemistry & Biochemistry Theses & Dissertations

The human immunodeficiency virus (HIV) reverse transcriptase (RT) (EC 2.7.7.49) is the central replication enzyme for HIV. In general, the kinetic mechanism for this and all other polymerases involves the ordered binding of two substrates: a primer-template (PT) followed by a deoxyribonucleoside triphosphate (dNTP). Previous investigations prompted this research when it was discovered that the substrate dNTP, in absence of PT, could protect a recombinant c-terminal mutant HIV-1 RT from inhibition by pyridoxal-5'-monophosphate (PLP), an active-site dNTP inhibitor. In contrast, the non-mutant recombinant HIV-1 RT required both substrates for protection from PLP inhibition. This investigation sought to determine if this …

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Dual Regulation Of Silent And Productive Infection In Monocytes By Distinct Human Immunodeficiency Virus Type 1 Determinants, Howard Gendelman, Peter Westervelt, Timothy Henkel, David B. Trowbridge, Jan Orenstein, John Heuser, Lee Ratner Jun 1992

Dual Regulation Of Silent And Productive Infection In Monocytes By Distinct Human Immunodeficiency Virus Type 1 Determinants, Howard Gendelman, Peter Westervelt, Timothy Henkel, David B. Trowbridge, Jan Orenstein, John Heuser, Lee Ratner

Nebraska Center for Virology: Faculty Publications

The regulation of human immunodeficiency virus type 1 infection and replication in primary monocytes was investigated by mutagenesis of recombinant proviral clones containing an env determinant required for the infectivity of monocytes. Virus replication was assayed by determination of reverse transcriptase activity in culture fluids and by recovery of virus from monocytes following cocultivation with uninfected peripheral blood mononuclear cells. Three virus replication phenotypes were observed in monocytes: productive infection, silent infection, and no infection. Incorporation of the monocytetropic env determinant in a full-length clone incapable of infection or replication in primary monocytes (no infection) conferred the capacity for highly …

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Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green May 1992

Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green

Dartmouth Scholarship

LP-BM5 retrovirus complex-infected C57BL/6 mice develop immunodeficiency, somewhat analogous to AIDS, termed murine AIDS (MAIDS). After secondary stimulation with syngeneic B-cell lymphomas from LP-BM5-infected mice, C57BL/6 mice produced vigorous CD8+ cytotoxic T lymphocytes specific for MAIDS-associated tumors. An anti-LP-BM5 specificity was suggested because spleen and lymph node cells from LP-BM5-infected mice served as target cells in competition assays, and cells from LP-BM5, but not ecotropic, virus-infected mice functioned as secondary in vitro stimulators to generate cytotoxic T lymphocytes to MAIDS tumors.

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Transformation Of A Continuous Rat Embryo Fibroblast Cell Line Requires Three Separate Domains Of Simian Virus 40 Large T Antigen., Jiyue Zhu, Philip W. Rice, Lisa Gorsch, Marina Abate, Charles N. Cole May 1992

Transformation Of A Continuous Rat Embryo Fibroblast Cell Line Requires Three Separate Domains Of Simian Virus 40 Large T Antigen., Jiyue Zhu, Philip W. Rice, Lisa Gorsch, Marina Abate, Charles N. Cole

Dartmouth Scholarship

Mouse C3H 10T1/2 cells and the established rat embryo fibroblast cell line REF-52 are two cell lines widely used in studies of viral transformation. Studies have shown that transformation of 10T1/2 cells requires only the amino-terminal 121 amino acids of simian virus 40 (SV40) large T antigen, while transformation of REF-52 cells requires considerably more of large T antigen, extending from near the N terminus to beyond residue 600. The ability of a large set of linker insertion, small deletion, and point mutants of SV40 T antigen to transform these two cell lines and to bind p105Rb was determined. Transformation …

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Identification And Characterization Of A Human Herpesvirus 6 Gene Segment That Trans Activates The Human Immunodeficiency Virus Type 1 Promoter, Yunqi Geng, Bala Chandran, Steven Josephs, Charles Wood Mar 1992

Identification And Characterization Of A Human Herpesvirus 6 Gene Segment That Trans Activates The Human Immunodeficiency Virus Type 1 Promoter, Yunqi Geng, Bala Chandran, Steven Josephs, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 6 (HHV-6) is a lymphotropic herpesvirus, and in vitro, HHV-6 can productively infect many of the same cell types as can human immunodeficiency virus (HIV). Coinfection by both viruses in vitro can lead to both activation of the HIV promoter and acceleration of cytopathic effects. We have previously demonstrated that a large, 22.25-kb cloned HHV-6 fragment, pZVB70, can trans activate HIV promoter expression in vitro. In this study, we show that the pZVB70 fragment can trans activate the HIV promoter in human T-cell lines as well as in the monkey kidney cell line CV-1. The pZVB70 insert was …

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The Inhibitory Effects Of The Extracts Of Zingiber Plants On The Adsorption, Growth, And Replication Of Phage Lpp-1 In Cyanobacterium, Ebby Paul Jido Jan 1992

The Inhibitory Effects Of The Extracts Of Zingiber Plants On The Adsorption, Growth, And Replication Of Phage Lpp-1 In Cyanobacterium, Ebby Paul Jido

Master's Theses

No abstract provided.

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Altered Expression Of Adenovirus 12 Dna-Binding Protein But Not Dna Polymerase During Abortive Infection Of Hamster Cells, Lynne A. Lucher, Benjawan Khuntirat, Jiansheng Zhao, Peter C. Angeletti Jan 1992

Altered Expression Of Adenovirus 12 Dna-Binding Protein But Not Dna Polymerase During Abortive Infection Of Hamster Cells, Lynne A. Lucher, Benjawan Khuntirat, Jiansheng Zhao, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Replication of human adenovirus type 12 DNA is blocked in abortively infected baby hamster kidney cells. The activity and accumulation of adenovirus 12 DNA polymerase is equivalent in infected hamster and human cell extracts. However, the accumulation of adenovirus type 12 DNA-binding protein is approximately 120-fold lower in extracts from infected hamster cells when compared to infected permissive human cells. This difference in accumulation is not because of replication of viral DNA during productive infection, since this difference is observed in the presence of hydroxyurea. The DNA-binding protein from infected hamster cells retains the ability to bind denatured DNA-cellulose. An …

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The Ability Of Simian Virus 40 Large T Antigen To Immortalize Primary Mouse Embryo Fibroblasts Cosegregates With Its Ability To Bind To P53., Jiyue Y. Zhu, Marina Abate, Philip W. Rice, Charles N. Cole Dec 1991

The Ability Of Simian Virus 40 Large T Antigen To Immortalize Primary Mouse Embryo Fibroblasts Cosegregates With Its Ability To Bind To P53., Jiyue Y. Zhu, Marina Abate, Philip W. Rice, Charles N. Cole

Dartmouth Scholarship

The large T antigen encoded by simian virus 40 (SV40) plays essential roles in the infection of permissive cells, leading to production of progeny virions, and in the infection of nonpermissive cells, leading to malignant transformation. Primary mouse embryo fibroblasts (MEFs) are nonpermissive for SV40, and infection by wild-type SV40 leads to immortalization and transformation of a small percentage of infected cells. We examined the ability of an extensive set of mutants whose lesions affect SV40 large T antigen to immortalize MEFs. We found that immortalization activity was retained by all mutants whose lesions are located upstream of codon 346. …

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The Inability Of Human Immunodeficiency Virus To Infect Chimpanzee Monocytes Can Be Overcome By Serial Viral Passage In Vivo, Howard Gendelman, Garth D. Ehrlich, Lisa M. Baca, Shawn Conley, Jorge Ribas, D. Chester Kalter, Monte S. Meltzer, Bernard J. Poiesz, Peter Nara Jul 1991

The Inability Of Human Immunodeficiency Virus To Infect Chimpanzee Monocytes Can Be Overcome By Serial Viral Passage In Vivo, Howard Gendelman, Garth D. Ehrlich, Lisa M. Baca, Shawn Conley, Jorge Ribas, D. Chester Kalter, Monte S. Meltzer, Bernard J. Poiesz, Peter Nara

Nebraska Center for Virology: Faculty Publications

Studies of lentivirus infection in ruminants, nonhuman primates, and humans suggest that virus infection of macrophages plays a central role in the disease process. To investigate whether human immunodeficiency virus type 1 (HIV-1) can infect chimpanzee macrophages, we recovered monocytes from peripheral blood mononuclear cells of HIV-1-negative animals and inoculated these and control human monocytes with a panel of four human-passaged monocytotropic virus strains and one chimpanzee-passaged isolate. HIV-1-infected human monocytes synthesized proviral DNA, viral mRNA, p24 antigen, and progeny virions. In contrast, except for the chimpanzee-passaged HIV-1 isolate, chimpanzee monocytes failed to support HIV-1 replication when cultured under both …

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Transactivation Of The Human Immunodeficiency Virus Promoter By Human Herpesvirus 6 (Hhv-6) Strains Gs And 2-29 In Primary Human T Lymphocytes And Identification Of Transactivating Hhv-6(Gs) Gene Fragments, Rebecca Horvat, Charles Wood, Steven Josephs, N. Balachandran Jun 1991

Transactivation Of The Human Immunodeficiency Virus Promoter By Human Herpesvirus 6 (Hhv-6) Strains Gs And 2-29 In Primary Human T Lymphocytes And Identification Of Transactivating Hhv-6(Gs) Gene Fragments, Rebecca Horvat, Charles Wood, Steven Josephs, N. Balachandran

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 6 (HHV-6) can activate the human immunodeficiency virus (HIV) promoter and accelerate cytopathic effects in HIV-infected human T cells. This study examines the regions of the HIV promoter required for HHVd transactivation in a heterogeneous population of primary human T lymphocytes with or without antigenic stimulation. Two different strains of HHV-6, GS and 229, transactivated the HIV promoter. The GS strain transactivated the promoter in both stimulated and resting T cells, while the 229 strain increased HIV promoter activity only in stimulated T cells. Three DNA clones containing HHV-6(GS) genomic fragments transactivated the HIV promoter in cotransfected T …

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Transactivation Of The Human Immunodeficiency Virus Promoter By Human Herpesvirus 6 (Hhv-6) Strains Gs And Z-29 In Primary Human T Lymphocytes And Identification Of Transactivating Hhv-6(Gs) Gene Fragments, Rebecca Horvat, Charles Wood, Steven Josephs, N. Balanchandran Jun 1991

Transactivation Of The Human Immunodeficiency Virus Promoter By Human Herpesvirus 6 (Hhv-6) Strains Gs And Z-29 In Primary Human T Lymphocytes And Identification Of Transactivating Hhv-6(Gs) Gene Fragments, Rebecca Horvat, Charles Wood, Steven Josephs, N. Balanchandran

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 6 (HHV-6) can activate the human immunodeficiency virus (HIV) promoter and accelerate cytopathic effects in HIV-infected human T cells. This study examines the regions of the HIV promoter required for HHV-6 transactivation in a heterogeneous population of primary human T lymphocytes with or without antigenic stimulation. Two different strains of HHV-6, GS and Z29, transactivated the HIV promoter. The GS strain transactivated the promoter in both stimulated and resting T cells, while the Z29 strain increased HIV promoter activity only in stimulated T cells. Three DNA clones containing HHV-6(GS) genomic fragments transactivated the HIV promoter in cotransfected T …

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Mapping The Transcriptional Transactivation Function Of Simian Virus 40 Large T Antigen., Jiyue Y. Zhu, Philip W. Rice, Michele Chamberlain, Charles N. Cole Jun 1991

Mapping The Transcriptional Transactivation Function Of Simian Virus 40 Large T Antigen., Jiyue Y. Zhu, Philip W. Rice, Michele Chamberlain, Charles N. Cole

Dartmouth Scholarship

T antigen is able to transactivate gene expression from the simian virus 40 (SV40) late promoter and from several other viral and cellular promoters. Neither the mechanisms of transactivation by T antigen nor the regions of T antigen required for this activity have been determined. To address the latter point, we have measured the ability of a set of SV40 large T antigen mutants to stimulate gene expression in CV-1 monkey kidney cells from the SV40 late promoter and Rous sarcoma virus (RSV) long terminal repeat (LTR) promoter. Transactivation, although reduced, was retained by an N-terminal 138-amino-acid fragment of T …

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Strain-Specific Neutralizing Determinant In The Transmembrane Protein Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Daniel P. Silva, Fulvia Dimarzo Veronese, Ronald C. Desrosiers Apr 1991

Strain-Specific Neutralizing Determinant In The Transmembrane Protein Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Daniel P. Silva, Fulvia Dimarzo Veronese, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Monoclonal antibody SF8/5E11, which recognizes the transmembrane protein (TMP) of simian immunodeficiency virus of macaque monkeys (SIVmac), displayed strict strain specificity. It reacted with cloned and uncloned SIVmac251 but not with cloned SIVmac142 and SIVmac239 on immunoblots. This monoclonal antibody neutralized infection by cloned, cell-free SIVmac251 and inhibited formation of syncytia by cloned SIVmac251-infected cells; these activities were specific to cloned SIVmac251 and did not occur with the other viruses. Site-specific mutagenesis was used to show that TMP amino acids 106 to 110 (Asp-Trp-Asn-Asn-Asp) determined the strain specificity of the monoclonal antibody. This strain-specific neutralizing determinant is located within a …

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Selection Of Genetic Variants Of Simian Immunodeficiency Virus In Persistently Infected Rhesus Monkeys, Dawn P. Wooley, Ronald C. Desrosiers Apr 1991

Selection Of Genetic Variants Of Simian Immunodeficiency Virus In Persistently Infected Rhesus Monkeys, Dawn P. Wooley, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Genetic and antigenic variation may be one means by which lentiviruses that cause AIDS avoid elimination by host immune responses. Genetic variation in the envelope gene (env) was studied by comparing the nucleotide sequences of 27 clones obtained from two rhesus monkeys infected with molecularly cloned simian immunodeficiency virus. All 27 clones differed from each other and differed from the input clone in the gp120 (SU) portion of the envelope gene. Nucleotide substitutions were shown to accumulate with time at an average rate of 8.5 per 1,000 per year in SU. Surprisingly, the majority of nucleotide substitutions (81%) resulted in …

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Rapid Detection Of Bovine Viral Diarrhea Virus By Polymerase Chain Reaction, O. J. Lopez, Fernando A. Osorio, Ruben O. Donis Mar 1991

Rapid Detection Of Bovine Viral Diarrhea Virus By Polymerase Chain Reaction, O. J. Lopez, Fernando A. Osorio, Ruben O. Donis

Nebraska Center for Virology: Faculty Publications

The polymerase chain reaction was used to detect genomic sequences of the positive-stranded RNA of bovine viral diarrhea virus (BVDV), a member of the family Togaviridae. Using a set of 20-bp primers located within the conserved 3' region of the BVDV genome, we were able to consistently amplify a 205-bp target sequence from BVDV cDNA. BVDV RNAs from cell culture-propagated BVDV reference strains, diverse unrelated cytopathic and noncytopathic field isolates, and clinical serum samples were transcribed to cDNA by using avian myeloblastosis virus reverse transcriptase and further specifically amplified by using the polymerase chain reaction assay. The amplification assay …

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The Viral Envelope Gene Is Involved In Macrophage Tropism Of A Human Immunodeficiency Virus Type 1 Strain Isolated From Brain Tissue, Zhen-Qian Liu, Charles Wood, Jay Levy, Cecilia Cheng-Mayer Dec 1990

The Viral Envelope Gene Is Involved In Macrophage Tropism Of A Human Immunodeficiency Virus Type 1 Strain Isolated From Brain Tissue, Zhen-Qian Liu, Charles Wood, Jay Levy, Cecilia Cheng-Mayer

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) strains isolated from the central nervous system (CNS) may represent a subgroup that displays a host cell tropism different from those isolated from peripheral blood and lymph nodes. One CNS-derived isolate, HIV-lSF128A , which can be propagated efficiently in primary macrophage culture but not in any T-cell lines, was molecularly cloned and characterized. Recombinant viruses between HIV-1SF128A and the peripheral blood isolate HIV-ISF2 were generated in order to map the viral gene(s) responsible for the macrophage tropism. The env gene sequences of the two isolates are about 91.1% homologous, with variations …

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The Viral Envelope Gene Is Involved In Macrophage Tropism Of A Human Immunodeficiency Virus Type 1 Strain Isolated From Brain Tissue, Zhen-Qian Lou, Charles Wood, Jay Levy, Cecilia Cheng-Mayer Dec 1990

The Viral Envelope Gene Is Involved In Macrophage Tropism Of A Human Immunodeficiency Virus Type 1 Strain Isolated From Brain Tissue, Zhen-Qian Lou, Charles Wood, Jay Levy, Cecilia Cheng-Mayer

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) strains isolated from the central nervous system (CNS) may represent a subgroup that displays a host cell tropism different from those isolated from peripheral blood and lymph nodes. One CNS-derived isolate, HIV-lSFl28A, which can be propagated efficiently in primary macrophage culture but not in any T-cell lines, was molecularly cloned and characterized. Recombinant viruses between HIV-lSF128A and the peripheral blood isolate HIV-lSF2 were generated in order to map the viral gene(s) responsible for the macrophage tropism. The env gene sequences of the two isolates are about 91.1% homologous, with variations …

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The Growth Of Simian Virus 40 (Sv40) Host Range/Adenovirus Helper Function Mutants In An African Green Monkey Cell Line That Constitutively Expresses The Sv40 Agnoprotein., Terryl P. Stacy, Michele Chamberlain, Susan Carswell, Charles N. Cole Jul 1990

The Growth Of Simian Virus 40 (Sv40) Host Range/Adenovirus Helper Function Mutants In An African Green Monkey Cell Line That Constitutively Expresses The Sv40 Agnoprotein., Terryl P. Stacy, Michele Chamberlain, Susan Carswell, Charles N. Cole

Dartmouth Scholarship

The simian virus 40 T-antigen carboxy-terminal mutants, dlA2459 and dlA2475, are cell line and temperature dependent for growth and plaque formation in monkey kidney cells. Although these mutants did form plaques on BSC-1 cells at 37 degrees C, they were about fivefold less efficient for plaque formation than wild-type simian virus 40. These mutants did not grow in CV-1 cells and did not synthesize agnoprotein in those cells. CV-1 cells which constitutively express the agnoprotein were permissive for mutant plaque formation. However, late mRNAs, virion proteins, and progeny virion yields did not accumulate to wild-type levels during mutant infection of …

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Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green Jun 1990

Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green

Dartmouth Scholarship

It was previously shown that spleen cells from endogenous ecotropic murine leukemia virus emv-14+ AKXL-5 mice fail to stimulate an anti-AKR/Gross virus cytolytic T-lymphocyte (CTL) response in a mixed lymphocyte culture with primed C57BL/6 responder spleen cells, whereas spleen cells from AKXL strains carrying the very similar emv-11 provirus do stimulate a response (Green and Graziano, Immunogenetics 23:106-110, 1986). We wished to determine whether the lack of response with AKXL-5 spleen cells was at the level of recognition between effector cell and target cell and whether the relevant mutation was within the emv-14 provirus. It is shown here that EMV-negative …

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Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole Dec 1989

Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole

Dartmouth Scholarship

Simian virus 40 (SV40) deletion mutants dlA2459 and dlA2475 express T antigens that lack the normal carboxy terminus. These mutants are called host range/helper function (hr/hf) mutants because they form plaques at 37 degrees C on BSC-1 and Vero monkey kidney cell lines but not on CV-1p monkey kidney cells. Wild-type SV40 can provide a helper function to permit growth of human adenoviruses in monkey kidney cells; the hr/hf mutants cannot. Progeny yields of hr/hf mutants are also cold sensitive in all cell lines tested. Patterns of viral macromolecular synthesis in three cell lines (Vero, BSC-1, and CV-1) at three …

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Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers Nov 1989

Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

The location of the translational termination codon for the transmembrane protein (TMP) varies in three infectious molecular clones of simian immunodeficiency virus from macaques (SIVmac). The SIVmac251 and SIVmac142 infectious clones have premature stop signals that differ in location by one codon; transfection of these DNAs into human HUT-78 cells yielded virus with a truncated TMP (28 to 30 kilodaltons [kDa]). The SIVmac239 infectious clone does not have a premature stop codon in its TMP-coding region. Transfection of HUT-78 cells with this clone initially yielded virus with a full-length TMP (41 kDa). …

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Linker Insertion Mutants Of Simian Virus 40 Large T Antigen That Show Trans-Dominant Interference With Wild-Type Large T Antigen Map To Multiple Sites Within The T-Antigen Gene., Jiyue Y. Zhu, Charles N. Cole Nov 1989

Linker Insertion Mutants Of Simian Virus 40 Large T Antigen That Show Trans-Dominant Interference With Wild-Type Large T Antigen Map To Multiple Sites Within The T-Antigen Gene., Jiyue Y. Zhu, Charles N. Cole

Dartmouth Scholarship

Linker insertion mutants affecting the simian virus 40 (SV40) large tumor (T) antigen were constructed by inserting a 12-base-pair oligonucleotide linker into restriction endonuclease cleavage sites located within the early region of SV40. One mutant, with the insertion at amino acid 5, was viable in CV-1p and BSC-1 cells, indicating that sequences very close to the amino terminus of large T could be altered without affecting the lytic infection cycle of SV40. All other mutants affecting large T were not viable. In complementation assays between the linker insertion mutants and either a late-gene mutant, dlBC865, or a host range/helper function …

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Use Of Trpe/Gag Fusion Proteins To Characterize Immunoreactive Domains On The Human Immunodeficiency Virus Type 1 Core Protein, Michael Windheuser, Gary Tegtmeier, Charles Wood Sep 1989

Use Of Trpe/Gag Fusion Proteins To Characterize Immunoreactive Domains On The Human Immunodeficiency Virus Type 1 Core Protein, Michael Windheuser, Gary Tegtmeier, Charles Wood

Nebraska Center for Virology: Faculty Publications

The human immunodeficiency virus (HIV) p24 core protein is one of the most immunogenic of HIV structural proteins. Infected individuals develop high titers of antibodies against p24 early in infection, which makes anti-p24 antibodies important serological markers. However, despite the clinical importance of the anti-p24 response, no systematic study to characterize the antigenic domains on the p24 protein has been reported. We report here on the use of 12 overlapping fragments of the HIV type 1 p24 protein, synthesized in bacteria as TrpE/Gag fusion proteins, to identify at least two and possibly three antigenic domains on the p24 protein. In …

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