Virology Commons^™

Correlation Between Precolonization Of Trigeminal Ganglia By Attenuated Strains Of Pseudorabies Virus And Resistance To Wild-Type Virus Latency, L. M. Schang, G. F. Kutish, Fernando A. Osorio

Nebraska Center for Virology: Faculty Publications

We compared the levels of latent pseudorabies virus (PRV) DNA in trigeminal ganglia (TG) of pigs after intranasal inoculation of different PRV strains by using quantitative DNA PCR. The extent of colonization attained in each case varied significantly according to the type of strain and inoculum dose, wild-type (WT) PRV being the most efficient strain in colonizing TG. When groups of pigs representing different levels of precolonization of TG with an attenuated PRV strain were challenged with WT PRV, it became evident that there is a statistically significant inverse correlation between the extent of precolonization attained by an attenuated PRV …

Alpha Interferon-Induced Antiretroviral Activities: Restriction Of Viral Nucleic Acid Synthesis And Progeny Virion Production In Human Immunodeficiency Virus Type 1-Infected Monocytes, Lisa Baca-Regen, Nina Heinzinger, Mario Stevenson, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Alpha interferon (IFN-a) restricts multiple steps of the human immunodeficiency virus type 1 (HIV-i) life cycle. A well-described effect of IFN-a is in the modulation of viral nucleic acid synthesis. We demonstrate that IFN-α influences HIV-1 DNA synthesis principally by reducing the production of late products of reverse transcription. The magnitude of IFN-α-induced downregulation of HIV-1 DNA and/or progeny virion production was dependent on the IFN-α concentration, the duration of cytokine administration, the multiplicity of infection, the viral strain, and the cycles of viral infection. Interestingly, reductions in viral DNAs could not fully account for the observed IFN-a-induced abrogation of …

Characterization Of An Antiviral Agent Based On Nonionic Surfactants And It's Effects On Human Dermal Fibroblasts, Ji Young Li

Biological Sciences Theses & Dissertations

The AIDS ·pandemic has directed various research endeavors towards finding an appropriate method for eliminating all potentially infectious material within bone allografts before implantation into a recipient. To that effect, Panavirocide was conceived by Medicine and Applied Science·s, Inc. This compound, in which three nonionic surfactants serve as the active agents, has been shown to inactivate HIV-1 particles within blood and blood products. Because Panavirocide has never been used with allografts, the purpose of the present research was to characterize the nonionic surfactants for the putative alteration of the formulation by determining the critical micelle concentration values and to determine …

Effects Of Natural Sequence Variation On Recognition By Monoclonal Antibodies Neutralize Simian Immunodeficiency Virus Infectivity, Weon Sang Choi, Catherine Collignon, Clotilde Thiriart, Dawn P. Wooley, E. J. Scott, Karen A. Kent, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

The determinants of immune recognition by five monoclonal antibodies (KK5, KK9, KK17, Senv7.1, and Senv101.1) that neutralize simian immunodeficiency virus infectivity were analyzed. These five neutralizing monoclonal antibodies were generated to native SIVmac251 envelope glycoprotein expressed by a vaccinia virus recombinant vector. All five recognize conformational or discontinuous epitopes and require native antigen for optimal recognition. These monoclonal antibodies also recognize SIVmac239 gp120, but they do not recognize gp120 of two natural variants of SIVmac239, 1-12 and 8-22, which evolved during the course of persistent infection in vivo (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843-1854, 1991). Recombinant viruses which …

Enhanced Competitiveness Of Tomato Bushy Stunt Virus Defective Interfering Rnas By Segment Duplication Or Nucleotide Insertion, K. Andrew White, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

We have analyzed atypical tomato bushy stunt virus defective interfering (DI) RNA species which accumulated during a passage series in protoplasts. We present a rationale for the order of appearance of these molecules and show, using competition assays, that either segment duplication or single nucleotide insertion can enhance DI RNA competitiveness. Possible mechanisms for the introduction of the modifications observed in these DI RNAs are discussed.

A Lion Lentivirus Related To Feline Immunodeficiency Virus: Epidemiologic And Phylogenetic Aspects, Eric W. Brown, Naoya Yuhki, Craig Packer, Stephen J. O'Brien

Biology Faculty Articles

Feline immunodeficiency virus (FIV) is a novel lentivirus that is genetically homologous and functionally analogous to the human AIDS viruses, human immunodeficiency virus types 1 and 2. FIV causes immunosuppression in domestic cats by destroying the CD4 T-lymphocyte subsets in infected hosts. A serological survey of over 400 free-ranging African and Asian lions (Panthera leo) for antibodies to FIV revealed endemic lentivirus prevalence with an incidence of seropositivity as high as 90%o. A lion lentivirus (FIV-Ple) was isolated by infection of lion lymphocytes in vitro. Seroconversion was documented in two Serengeti lions, and discordance of mother-cub serological status …

Purification And Characterization Of Two Forms Of A High-Molecular-Weight Cysteine Proteinase (Porphypain) From Porphyromonas Gingivalis, Pawel Ciborowski, Makoto Nishikata, Roger D. Allen, Marilyn S. Lantz

Nebraska Center for Virology: Faculty Publications

Porphyromonas gingivalis, an organism implicated in the etiology and pathogenesis of human periodontal diseases, produces a variety of potent proteolytic enzymes, and it has been suggested that these enzymes play a direct role in the destruction of periodontal tissues. We now report that two cell-associated cysteine proteinases of P. gingivalis W12, with molecular masses of approximately 150 kDa (porphypain-1) and 120 kDa (porphypain-2), as determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, have been separated and purified to apparent homogeneity. These proteinases appear to be SDS-stable conformational variants of a 180-kDa enzyme, and they are the largest cysteine proteinases …

Molecular Analysis Of The Rfb Gene Cluster Of A Group D2 Salmonella Enterica Strain: Evidence For Its Origin From An Insertion Sequence-Mediated Recombination Event Between Group E And Dl Strains, Shi-Hua Xiang, Matthew Hobbs, Peter R. Reeves

Nebraska Center for Virology: Faculty Publications

The Salmonella enterica O antigen is a highly variable surface polysaccharide composed of a repeated oligosaccharide (the O unit). The O unit produced by serogroup D2 has structural features in common with those of groups Dl and El, and hybridization studies had previously suggested that the D2 rfb gene cluster responsible for O-unit biosynthesis is indeed a hybrid of the two. In this study, the rfb gene cluster was cloned from a group D2 strain of S. enterica sv. Strasbourg. Mapping, hybridization, and DNA sequencing showed that the organization of the D2 rfb genes is similar to that of group …

High Rates Of Frameshift Mutations Within Homo-Oligomeric Runs During A Single Cycle Of Retroviral Replication, Dawn P. Wooley, H. M. Temin

Neuroscience, Cell Biology & Physiology Faculty Publications

Homo-oligomeric runs were inserted into a spleen necrosis virus-based retrovirus vector to determine the nature and rate of mutations within runs of 10 to 12 identical nucleotides during a single replication cycle. Clones of helper cells containing integrated copies of retroviral vectors were used to produce virus for infection of target (nonhelper) cells. Proviral sequences from target cell clones were compared with proviral sequences from helper cell clones to study mutations that occurred during a single cycle of replication. In addition to the internal region spanning the homo-oligomeric inserts, a naturally occurring run of 10 T's in the long terminal …

Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi

Dartmouth Scholarship

Cytolytic T lymphocytes (CTL) can be raised against C57BL/6 B-cell lymphomas from mice with LP-BM5 murine leukemia virus-induced AIDS (MAIDS). Adoptive transfer of polyclonal anti-MAIDS tumor CTL or two CTL clones specific for the B6-1710 MAIDS lymphoma caused preservation of major histocompatibility complex-restricted and allogeneic CTL responses, which may be interpreted as indices of protection from LP-BM5 murine leukemia virus-induced immunodeficiency.

Phylogenetic Associations Of Human And Simian T-Cell Leukemia/Lymphotropic Virus Type I Strains: Evidence For Interspecies Transmission, Igor J. Koralnik, Enzo Boeri, W. Carl Saxinger, Anita Lo Monico, Jake Fullen, Antoine Gessain, Hong-Guang Guo, Robert C. Gallo, Phillip Markham, Vaniambadi Kalyanaraman, Vanessa Hirsch, Jonathan Allan, Krishna Murthy, Patricia Alford, Jill Pecon-Slattery, Stephen J. O'Brien, Genoveffa Ranchini

Biology Faculty Articles

Homologous env sequences from 17 human T-leukemia/lymphotropic virus type I (HTLV-I) strains from throughout the world and from 25 simian T-leukemia/lymphotropic virus type I (STLV-I) strains from 12 simian species in Asia and Africa were analyzed in a phylogenetic context as an approach to resolving the natural history of these related retroviruses. STLV-I exhibited greater overall sequence variation between strains (1 to 18% compared with 0 to 9% for HTLV-I), supporting the simian origin of the modern viruses in all species. Three HTLV-I phylogenetic clusters or clades (cosmopolitan, Zaire, and Melanesia) were resolved with phenetic, parsimony, and likelihood analytical procedures. …

Phylogenetic Analysis Of Segment 10 From African Horsesickness Virus And Cognate Genes From Other Orbiviruses, Rafael O. De Sá, Marla Zellner, Marvin J. Grubman

Biology Faculty Publications

Utilizing the reverse transcriptase-polymerase chain reaction (RT-PCR) procedure, we have synthesized full-length copies of segment 10 from African horsesickness virus (AHSV) serotypes 1,4 and 8. The genes were cloned, sequenced and compared with the sequence of the cognate gene from AHSV serotypes 3 and 9. Sequences were analyzed to assess evolutionary relationships among serotypes using cladistics. Based on this analysis the data support a close relationship between serotypes 4 and 9 and between serotypes 1 and 8 and a closer relationship of serotype 3 to the 4 and 9 group.

The Amino-Terminal Functions Of The Simian Virus 40 Large T Antigen Are Required To Overcome Wild-Type P53-Mediated Growth Arrest Of Cells., Robin S. Quartin, Charles N. Cole, James M. Pipas, Arnold J. Levine

Dartmouth Scholarship

High levels of the p53 tumor suppressor protein can block progression through the cell cycle. A model system for the study of the mechanism of action of wild-type p53 is a cell line (T64-7B) derived from rat embryo fibroblasts transformed by activated ras and a temperature-sensitive murine p53 gene. At 37 to 39 degrees C, the murine p53 protein is in a mutant conformation and the cells actively divide, whereas at 32 degrees C, the protein has a wild-type conformation and the cells arrest in the G1 phase of the cell cycle. Wild-type simian virus 40 large T antigen and …

Virus Diseases Of Subterranean Clover Pastures And Their Management, David Ferris, Roger Jones

Journal of the Department of Agriculture, Western Australia, Series 4

In Western Australia and southern Australia generally, subterranean clover mottle (SCMV) and bean yellow mosaic (BYMV) are the most damaging virus diseases of subterranean clover pastures.

Although infected plants cannot be cured of virus infection, pastures can be managed to reduce both virus spread and persistence from year to year. Management options depend on which virus is present and include reseeding with resistant varieties; changing the pasture composition so that non-host species predominate; altering grazing practices to limit spread; and application of pesticide sprays to kill aphids.

Nonhomologous Rna Recombination In Tombusviruses: Generation And Evolution Of Defective Interfering Rnas By Stepwise Deletions, K. Andrew White, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

We used a protoplast system to study the mechanisms involved in the generation and evolution of defective interfering (DI) RNAs of tomato bushy stunt tombusvirus (TBSV). Synthetic transcripts corresponding to different naturally occurring TBSV DI RNAs, or to various artificially constructed TBSV defective RNAs, were analyzed. The relative levels of competitiveness of different DI RNAs were determined by coinoculating their corresponding transcripts into protoplasts along with helper genomic RNA transcripts and monitoring the level of DI RNA accumulation. Further studies were performed to assess the contribution of naked DI RNA stability and DI RNA encapsidation efficiency to the observed levels …