Microbiology Commons^™

Murine Epidermal Cell Antigen (Skn)-Directed Autoimmunity Induced By Transfer Of Cd4+ T Cells, Susan H. Jackman, Shivaleela Keerthy, Giselle Perry

Biochemistry and Microbiology

While pathogenic T cells have been identified for several diseases with epithelial cell damage, an autoimmune T cell-mediated response targeted against a known keratinocyte antigen has not been reported. Previously we described an autoimmune response directed to the mouse epidermal cell antigens, Skn. For our murine model, primed Skn-immune lymphocytes are adoptively transferred to recipients, which develop lesions at the site of mild skin trauma. In this study we investigated the nature of the autoimmune component of the Skn response. A time-course study demonstrated a relationship between the number of primed Sknimmune cells injected and the severity of skin lesions …

Serotyping Group B Streptococci In A Small Community Hospital: An Analysis Of Distribution And Site Of Isolation, Jennifer M. Smith, Jason A. Rexroth, David G. Chaffin, Susan H. Jackman

Biochemistry and Microbiology

Objective: To determine the prevalence and site of isolation of different serotypes of group B streptococcus (GBS) colonization or infection at a small community hospital.

Methods: GBS isolates were obtained from a small community hospital and were then serotyped as la, Ib, II, III, IV, V or non-typeable. Hospital records were reviewed for patient sex, age and pregnancy status as well as the site of GBS isolation.

Results: GBS serotypes Ia, III and V were most common and accounted for over 60% of the total number of isolates. Serotype Ia was most prevalent in reproductive-age females, while serotypes V and …

Stable Replication Of Papillomavirus Genomes In Saccharomyces Cerevisiae, Peter C. Angeletti, Kitai Kim, Fiona J. Fernandes, Paul F. Lambert

Nebraska Center for Virology: Faculty Publications

Papillomaviruses normally replicate in stratified squamous epithelial tissues of their mammalian hosts, in which the viral genome is found as a nuclear plasmid. Two viral proteins, E1, a helicase, and E2, a transcriptional activator and plasmid maintenance factor, are known to contribute to the episomal replication of the viral genome. Recently, our laboratory discovered that papillomaviruses can also replicate in an E1-independent manner in mammalian cells (K. Kim and P. F. Lambert, Virology, in press; K. Kim and P. F. Lambert, submitted for publication). In this study, we describe experiments investigating the capacity of the human papillomavirus type 16 (HPV16) …

Type 4 Pilus Biogenesis And Type Ii-Mediated Protein Secretion By Vibrio Cholerae Occur Independently Of The Tonb-Facilitated Proton Motive Force, Niranjan Bose, Shelley M. Payne, Ronald K. Taylor

Dartmouth Scholarship

In Vibrio cholerae, elaboration of toxin-coregulated pilus and protein secretion by the extracellular protein secretion apparatus occurred in the absence of both TonB systems. In contrast, the cognate putative ATPases were required for each process and could not substitute for each other.

Enrichments And Isolations Of Mesophilic And Thermophilic Iron-Reducing Microbes From Deep-Sea Hydrothermal Vents And The Deep Subsurface, Melissa Mary Kendall

Dissertations and Theses

Microbes inhabiting the deep subsurface play an important role in geochemical processes and may be of practical value in bioremediation and biotechnology. Hydrothermal vents and the deep gold mines of South Africa have be likened to "windows" into the subsurface biosphere. The aim of this research was to isolate and characterize microbes involved in iron-cycling from deep-sea hydrothermal vents and from the deep gold mines of the Witwatersrand Basin. Three mesophilic bacteria, strains BB4, W3, and A6 were isolated from sulfide chimneys at 13°N and a thermophilic bacterium, strain GB21 was isolated from Guaymas Basin on the East Pacific Rise. …

Characterization Of The Surface Morphology Of Bacillus Spores By Atomic Force Microscopy, Ruth A. Zolock

Theses and Dissertations

The surface morphology of Bacillus spores was resolved by atomic force microscopy in order to determine if characteristic surface features could be used to distinguish between closely related species. Four strains were studied: Bacillus anthracis Sterne strain, Bacillus thuringiensis var. kurstaki, Bacillus cereus strain 569, and Bacillus globigii var. niger. The spores were separated from a nutrient agar culture by filtering and centrifugation, suspended in deionized water, and immobilized on a graphite substrate by spin-coating. Atomic force microscopy imaging was done using intermittent contact mode, in air, under reduced humidity. Seven to ten spores of each species were fully characterized …

Construction And Characterization Of A Chimeric Virus (Biv/Hiv-1) Carrying The Bovine Immunodeficiency Virus Gag-Pol Gene: Research Letters, Guomin Chen, Shuhui Wang, Kun Xiong, Jinzhong Wang, Tao Ye, Wenping Dong, Qi Wang, Qimin Chen, Yunqi Geng, Charles Wood, Yi Zeng

Nebraska Center for Virology: Faculty Publications

HIV-1HXB2 5′LTR region, most of BIVR29 gag-pol segment and HIV-1HXB2 pol IN-3′LTR region were respectively amplified. A chimeric clone, designated as pHBIV₃₇₅₃, was constructed by cloning three fragments sequentially into pUC18. MT4 cells were transfected with pHBIV₃₇₅₃. The replication and expressions of the chimeric virus (HBIV₃₇₅₃) were monitored by RT activity and IFA. The results firstly demonstrated that it is possible to generate a new type of the BIV/HIV-1 chimeric virus containing BIV gag-pol gene.

Cyanonews (Vol. 17, No. 1, 2002), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

A Mechanistic Study Of Myoglobin Nephrotoxicity, Jennifer L. Minigh

Theses, Dissertations and Capstones

Myoglobin is an endogenous protein that can become nephrotoxic under certain conditions such as crush injuries, drug overdose, and seizures where prolonged contraction of muscle leads to cell death and leakage of myoglobin. The mechanism of myoglobin-induced nephrotoxicity is not fully understood. The purpose of this study was to characterize the sequence and mechanistic events associated with the in vitro toxicity of myoglobin in renal cortical slices. Renal tissue was isolated from Fischer 344 rats. Slices of renal cortex were prepared by freehand. These slices were then incubated for 60-180 minutes with myoglobin (0-12 mg/mL) pretreated with 4 mM ascorbic …

Characterization Of Host-Bacteria Interactions Contributing To Group B Streptococcus Colonization, Jennifer Marie Smith

Theses, Dissertations and Capstones

Group B streptococcus (GBS) is the leading cause of life-threatening bacterial infections during the first three months of life. GBS is also a frequent cause of maternal postpartum infections. Both types of infections stem from maternal vaginal and/or rectal colonization with GBS in the perinatal period. Limited information is available concerning how the colonization process occurs and what role the host immune system may play in the establishment of persistent colonization by GBS. The complex interactions between the immune system and GBS normally should end in clearance of the bacteria. However, since colonization by GBS occurs in a large number …

Humboldt Journal Of Microbiology: Volume 5, Number 1-May 2002, Press Humboldt

Humboldt Journal of Microbiology

No abstract provided.

Characterization Of Cd4-Induced Epitopes On The Hiv Type 1 Gp120 Envelope Glycoprotein Recognized By Neutralizing Human Monoclonal Antibodies, Shi-Hua Xiang, Najah Doka, Rabeéa K. Choudhary, Joseph Sodroski, James E. Robinson

Nebraska Center for Virology: Faculty Publications

The entry of human immunodeficiency virus (HIV-1) into target cells typically requires the sequential binding of the viral exterior envelope glycoprotein, gp120, to CD4 and a chemokine receptor. CD4 binding exposes gp120 epitopes recognized by CD4-induced (CD4i) antibodies, which can block virus binding to the chemokine receptor. We identified three new CD4i antibodies from an HIV-1-infected individual and localized their epitopes. These epitopes include a highly conserved gp120 β-strand encompassing residues 419–424, which is also important for binding to the CCR5 chemokine receptor. All of the CD4i antibodies inhibited the binding of gp120–CD4 complexes to CCR5. CD4i antibodies and …

The Genome Of Swinepox Virus, C. L. Afonso, E. R. Tulman, Z. Lu, L. Zsak, Fernando A. Osorio, C. Balinsky, G. F. Kutish, D. L. Rock

Nebraska Center for Virology: Faculty Publications

Swinepox virus (SWPV), the sole member of the Suipoxvirus genus of the Poxviridae, is the etiologic agent of a worldwide disease specific for swine. Here we report the genomic sequence of SWPV. The 146-kbp SWPV genome consists of a central coding region bounded by identical 3.7-kbp inverted terminal repeats and contains 150 putative genes. Comparison of SWPV with chordopoxviruses reveals 146 conserved genes encoding proteins involved in basic replicative functions, viral virulence, host range, and immune evasion. Notably, these include genes with similarity to genes for gamma interferon (IFN-γ) receptor, IFN resistance protein, interleukin-18 binding protein, IFN-α/β binding protein, …

Identification Of A Genetic Locus Involved In Ppgpp Metabolism In Escherichia Coli, Roxanne Enid Garza

Theses and Dissertations - UTB/UTPA

Two genes involved in the metabolism of ppGpp are relA and spoT . A relX mutant has altered ppGpp levels, so relX may be a regulator of the RelA or SpoT enzymes. The growth of the relX mutant has been reported to be both temperature and leucine sensitive. It was discovered in this work that this relX mutant is not temperature sensitive, however it is leucine sensitive. The original goal was to study effects of the relX gene on ppGpp metabolism. During the process of mapping the relX gene, it was discovered that the leucine sensitivity was caused by some …

Purification And Characterization Of Hemolymph Juvenile Hormone Esterase From The Cricket, Gryllus Assimilis, Anthony J. Zera, Travis Sanger, Jeremiah Hanes, Lawrence G. Harshman

Anthony Zera Publications

Juvenile hormone esterase (JHE) from the serum of the cricket, Gryllus assimilis, was purified to homogeneity in a four-step procedure involving polyethylene glycol precipitation, hydrophobic interaction FPLC, and ion exchange FPLC. This procedure could be completed in 4 days and resulted in a greater than 900-fold purification with greater than 30% recovery. The purified enzyme exhibited a single band on a silver-stained SDS PAGE gel and had an apparent subunit molecular mass of 52 kDa. The native subunit molecular mass, determined by gel permeation FPLC, was 98 kDa, indicating that JHE from Gryllus assimilis is a dimer of two …

Mutagenic Stabilization And/Or Disruption Of A Cd4-Bound State Reveals Distinct Conformations Of The Human Immunodeficiency Virus Type 1 Gp120 Envelope Glycoprotein, Shi-Hua Xiang, Peter D. Kwong, Rishi Gupta, Carlo D. Rizzuto, David J. Casper, Richard Wyatt, Liping Wang, Wayne A. Hendrickson, Michael L. Doyle, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The human immunodeficiency virus type 1 (HIV-1) gp120 exterior envelope glycoprotein is conformationally flexible. Upon binding to the host cell receptor CD4, gp120 assumes a conformation that is recognized by the second receptor, CCR5 and/or CXCR4, and by the CD4-induced (CD4i) antibodies. Guided by the X-ray crystal structure of a gp120-CD4-CD4i antibody complex, we introduced changes into gp120 that were designed to stabilize or disrupt this conformation. One mutant, 375 S/W, in which the tryptophan indole group is predicted to occupy the Phe 43 cavity in the gp120 interior, apparently favors a gp120 conformation closer to that of the CD4-bound …

Human Immunodeficiency Virus Type 1 (Hiv-1) Tat Induces Nitric-Oxide Synthase In Human Astroglia, Xiaojuan Liu, Malabendu Jana, Subhajit Dasgupta, Sreenivas Koka, Jun He, Charles Wood, Kalipada Pahan

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) infection is known to cause neuronal injury and dementia in a significant proportion of patients. However, the mechanism by which HIV-1 mediates its deleterious effects in the brain is poorly defined. The present study was undertaken to investigate the effect of the HIV-1 tat gene on the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astroglia. Expression of the tat gene as RSV- tat but not that of the CAT gene as RSV-CAT in U373MG astroglial cells led to the induction of NO production and the expression of iNOS …

Il-12 Plasmid Delivery By In Vivo Electroporation For The Successful Treatment Of Established Subcutaneous B16.F10 Melanoma, M. Lee Lucus, Loree Heller, Domenico Coppola, Richard Heller

Bioelectrics Publications

Interleukin-12 (IL-12) has been used in numerous immunotherapy protocols against melanoma. However, delivery of IL-12 in the form of recombinant protein can result in severe toxicity, and gene therapy has had limited success against B16.F10 murine melanoma. The purpose of this study was to examine the effectiveness of in vivo electroporation for the delivery of plasmid DNA encoding IL-12 as an antitumor agent against B16.F10 melanoma. We treated mice bearing established B16.F10 melanoma tumors with intratumoral (i.t.) or intramuscular (i.m.) injections of a plasmid encoding IL-12, followed by in vivo electroporation. For i.t. treatments, we used an applicator containing six …

Gemfibrozil, A Lipid-Lowering Drug, Inhibits The Induction Of Nitric-Oxide Synthase In Human Astrocytes, Kalipada Pahan, Malabendu Jana, Xiaojuan Liu, Bradley S. Taylor, Charles Wood, Susan M. Fischer

Nebraska Center for Virology: Faculty Publications

Gemfibrozil, a lipid-lowering drug, inhibited cytokine- induced production of NO and the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astrocytes. Similar to gemfibrozil, clofibrate, another fibrate drug, also inhibited the expression of iNOS. Inhibition of human iNOS promoter-driven luciferase activity by gemfibrozil in cytokine-stimulated U373MG astroglial cells suggests that this compound inhibits the transcription of iNOS. Since gemfibrozil is known to activate peroxisome proliferator- activated receptor-α (PPAR-α), we investigated the role of PPAR- α in gemfibrozil-mediated inhibition of iNOS. Gemfibrozil induced peroxisome proliferator-responsive element (PPRE)-dependent luciferase activity, which was inhibited by the expression of …

Development Of A Genomic Approach For The Study Of A Coryneform Bacterial Collection., Carole Feurer

Theses

In the last few years, genomics has profoundly changed research in the biological sciences and in particular in microbiology. Recent studies have demonstrated that comparative genomics is a powerful approach contributing to a deeper understanding of the evolution of microorganisms. Bacterial collections are important resources of microorganisms, however, the potential that genomics has to offer remains to be realised as it is still virtually absent in any study involving strain collections. This feature thus framed the experimental objectives for this study, whose aim was to define the most comprehensive way to apply genomic based methods (high throughput sequencing and bioinformatics) …

Campylobacter Spp: A Molecular Investigation Of Transmission Through The Food Chain In Ireland, Brigid Lucey

Theses

The purpose of this study was to investigate the epidemiology of thermophilic Campylobacter infections in Ireland, and to assess antimicrobial resistance among animal isolates and its relevance to human enteric infection with Campylobacter. The first part of the study focused on 84 isolates of human, poultry and porcine origins, isolated between 1996 and 1998 in the Cork region. These isolates were identified to species level using a combination of biochemical and molecular methods. Campylobacter jejuni (C. jejuni) was the predominant organism among human and poultry isolates, whilst all of the porcine isolates examined were identified as C. coli. DNA amplification …

Functional Requirement Of Aquaporin-5 In Plasma Membranes Of Sweat Glands, Lene N. Nejsum, Tae-Hwan Kwon, Uffe B. Jensen, Ornella Fumagalli, Jørgen Frøkiaer, Carissa M. Krane, Anil G. Menon, Landon S. King, Peter C. Agre, Søren Nielsen

Biology Faculty Publications

The distribution and function of aquaporins (AQPs) have not previously been defined in sweat glands. In this study, AQP1, AQP3, and AQP5 mRNA were demonstrated in rat paw by reverse transcription (RT)–PCR, but AQP2 and AQP4 were not. AQP1, AQP3, and AQP5 protein were confirmed in these tissues by immunoblotting. AQP1 was identified in capillary endothelial cells by immunohistochemical labeling, but not in sweat glands or epidermis. Abundant AQP3 expression was seen in basal levels of epidermis, but not in sweat glands. AQP2 and AQP4 were not observed in either skin or sweat glands. Immunohistochemical labeling revealed abundant AQP5 in …

Rickettsial Infection In Dermacentor Variabilis (Acari : Ixodidae) Inhibits Transovarial Transmission Of A Second Rickettsia, Kevin R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, Abdu F. Azad

Biological Sciences Faculty Publications

This study examined the ability of ticks to maintain multiple species of spotted fever group rickettsiae via transovarial transmission. Using a capillary feeding method, previously established Rickettsia montana- and Rickettsia rhipicephali-infected cohorts of Dermacentor variabilis (Say) were exposed to R. rhipicephali and R. montana, respectively, in two reciprocal challenge experiments. Eggs collected from individual females, for two successive generations, of each cohort were assessed for rickettsial infection by polymerase chain reaction for each challenge experiment. Assessment of the eggs from challenged ticks identified that both R. montana- and R. rhipicephali-infected ticks were refractory to their …

A Note On Cascade Climbing Of Migrating Goby And Shrimp Postlarvae In Two Maui Streams, M. Eric Benbow, Leslie Luchar Orzetti, Mollie D. Mcintosh, Albert J. Burky

Biology Faculty Publications

In this study, we documented cascade climbing rates of 133 and 230 postlarvae of Lentipes concolor (O‘opu alamo‘o) and Atyoida bisulcata (Opae kahaole), respectively, from two streams on the island of Maui, Hawaii. Climbing measurements and observations were made of postlarvae at the water-substrate interface in cascade habitats of constricted water flow. Both species were observed to move in short bursts of forward progression within or above the pulsing water-substrate interface. Goby postlarval climbing rates ranged from 0.04 – 1.50 cm s–1 and were slower than shrimp rates which ranged from 0.30 – 3.06 cm s–1. The high variability is …

Cd28 Costimulation Requirement For Interferon-Y Secretion By Natural Killer T Cells During Hepatitis B Virus Infection, Paul J. Renick

Browse all Theses and Dissertations

Natural Killer T cells (NKT cells) are a unique subset of lymphocytes that express natural killer (NK) and T cell receptors (TCR). The NKT cell population includes four separate subclasses. This paper will focus on Category I NKT cells which possess a canonical TCR receptor (Va14Ja281) that recognizes only hydrophobic antigens presented by CD1d molecules. These cells are believed to play an important regulatory role in immunity. A variety of disease conditions, including cancer, infections and Type I diabetes, are controlled by NKT cells. NKT cells are also capable of secreting large quantities of cytokines, namely interleukin-4 (IL-4) and interferon-gamma …

Efficient Infection Of Nicotiana Benthamiana By Tomato Bushy Stunt Virus Is Facilitated By The Coat Protein And Maintained By P19 Through Suppression Of Gene Silencing, Feng Qu, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

Tomato bushy stunt virus (TBSV) is one of few RNA plant viruses capable of moving systemically in some hosts in the absence of coat protein (CP). TBSV also encodes another protein (p19) that is not required for systemic movement but functions as a symptom determinant in Nicotiana benthamiana. Here, the role of both CP and p19 in the systemic spread has been reevaluated by utilizing transgenic N. benthamiana plants expressing the movement protein (MP) of Red clover necrotic mosaic virus and chimeric TBSV mutants that express CP of Turnip crinkle virus. Through careful examination of the infection phenotype …

Phylogenetic And Phenotypic Analysis Of Hiv Type 1 Env Gp120 In Cases Of Subtype C Mother-To-Child Transmission, Hong Zhang, Guillermo Ortí, Qiujiang Du, Jun He, Chipepo Kankasa, Ganapati Bhat, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) subtype C constitutes a majority of the newly transmitted cases of HIV-1 in many developing countries. There is growing evidence suggesting that subtype C viruses may display characteristics that make them distinct from subtype B and other subtypes, and such differences may affect its transmission and pathogenesis in infected individuals. In this study, HIV-1 sequences from the C2–V4 region of the envelope gene were analyzed from four infected mother–infant pairs (MIPs) after perinatal transmission in Zambia. We found that all viral isolates from four Zambian MIPs were of the subtype C HIV-1 subgroup. All …

Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban

Nebraska Center for Virology: Faculty Publications

Molecular chaperone complexes containing heat shock protein (Hsp) 70 and Hsp90 are regulated by cochaperones, including a subclass of regulators, such as Hsp70 interacting protein (Hip), C-terminus of Hsp70 interacting protein (CHIP), and Hsp70-Hsp90 organizing factor (Hop), that contain tetratricopeptide repeats (TPRs), where Hsp70 refers to Hsp70 and its nearly identical constitutive counterpart, Hsc70, together. These proteins interact with the Hsp70 to regulate adenosine triphosphatase (ATPase) and folding activities or to generate the chaperone complex. Here we provide evidence that small glutamine-rich protein/viral protein U–binding protein (SGT/UBP) is a cochaperone that negatively regulates Hsp70. By “Far-Western” and pull-down assays, SGT/UBP …

Cellular Tropisms And Co-Receptor Usage Of Hiv-1 Isolates From Vertically Infected Children With Neurological Abnormalities And Rapid Disease Progression, Micheline Mccarthy, Jun He, Denise Auger, Rebeca Geffin, Cecilia Hutto, Charles Wood, Gwendolyn Scott

Nebraska Center for Virology: Faculty Publications

The longitudinal evolution of HIV-1 phenotypes was studied in a cohort of six vertically infected children with early onset and rapid progression of clinical disease. Among 30 viral isolates obtained from peripheral blood, tropisms for both human blood-derived cells (macrophages, T-lymphocytes), and for human neural (brain-derived) cells (microglia, astrocytes) were determined, as was chemokine co-receptor usage. All children harbored from birth macrophage-tropic isolates using the CCR5 co-receptor. Two children later developed T-cell tropic isolates with CXCR4 and CCR3 usage. While all six patients developed neurological abnormalities, only three produced neural cell tropic isolates, which used CCR5. However, early and persistent …

Effects Of Nonequilibrium Atmospheric Pressure Plasmas On The Heterotrophic Pathways Of Bacteria And On Their Cell Morphology, Mounir Laroussi, J. Paul Richardson, Fred C. Dobbs

OES Faculty Publications

To date, most research on the interaction of nonequilibrium, atmospheric pressure plasma discharges with bacteria has concentrated on the germicidal effects. Therefore, published results deal mainly with killing efficacy and little attention is given to physical mechanisms and biochemical pathways and their potential alterations when cells of microorganisms are exposed to the plasma. In this letter, an attempt to investigate the effects of plasma exposure on the biochemical pathways of bacteria is presented. In addition, using electron microscopy, we investigate if any gross morphological changes take place when cells are exposed to a lethal dose of plasma. We are testing …