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Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury

School of Veterinary and Biomedical Sciences: Faculty Publications

It has been suggested that T cell immunoglobulin mucin (Tim)-1 expressed on T cells serves to positively costimulate T cell responses. However, crosslinking of Tim-1 by its ligand Tim-4 resulted in either activation or inhibition of T cell responses, thus raising the issue of whether Tim-1 can have a dual function as a costimulator. To resolve this issue, we tested a series of monoclonal antibodies specifi c for Tim-1 and identifi ed two antibodies that showed opposite functional effects. One anti–Tim-1 antibody increased the frequency of antigen-specifi c T cells, the production of the proinfl ammatory cytokines IFN-γ and IL-17, …

Su.32. Myelin-Specific Regulatory T Cells Accumulate In The Central Nervous System, But Fail To Suppress Pathogenic Effector T Cells At The Peak Of Autoimmune Inflammation [Abstract Only], Thomas Korn, Mohamed Oukka, Jay Reddy, Estelle Betelli, Amit Awasthi, Raymond Sobel, Kai Wucherpfennig, Vijay K. Kuchroo

Jay Reddy Publications

Treatment with ex vivo generated regulatory T cells (Treg) has been regarded as highly attractive therapeutic approach for autoimmune diseases. However, the dynamics and function of T-reg in autoimmunity are not well understood. Thus, we developed Foxp3gfp “knock-in” mice and myelin oligodendrocyte glycoprotein (MOG)35–55/IAb tetramers to track autoantigen-specific effector T cells (T-eff) and T-reg in vivo during experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. Following immunization with the encephalitogenic peptide MOG35–55 emulsified in complete Freund's adjuvant, MOG35–55-tetramer-reactive, Foxp3+ T-reg expanded in the peripheral lymphoid compartment and readily accumulated in the central nervous system (CNS), but did not prevent …

Genetic Microheterogeneity And Phenotypic Variation Of Helicobacter Pylori Arginase In Clinical Isolates, Justin Hovey, Emily Watson, Melanie Langford, Ellen Hildebrandt, Sangeetha Bathala, Jeffrey Bolland, Domenico Spadafora, George Mendz, David Mcgee

School of Biological Sciences: Faculty Publications

Background: Clinical isolates of the gastric pathogen Helicobacter pylori display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of H. pylori to survive the stomach acid is due, in part, to the arginase-urease enzyme system. Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea, and urease hydrolyzes urea to carbon dioxide and ammonium, which can neutralize acid.

Results: The degree of variation in arginase was explored at the DNA sequence, enzyme activity and protein expression levels. To this end, arginase activity was measured from 73 minimally-passaged clinical isolates and six laboratory-adapted strains …

Molecular Mechanisms Of Olfactory Neurodegeneration, Radhika Anand Vaishnav

University of Kentucky Doctoral Dissertations

Olfactory sensory decline has been associated with normal aging as well as neurodegenerative disorders, yet the underlying mechanisms are unclear. The overall aim of this dissertation was to investigate the fundamental molecular and cellular mechanisms associated with olfactory neurodegeneration. This investigation uses an integrative approach, combining proteomics and gene expression analyses with cellular and tissuelevel characterization. Using these approaches, two model systems were investigated: 1) normally aging C57BL/6 mice of ages 1.5-, 6- and 20-months; and 2) a mouse model of elevated endogenous oxidative stress-associated neurodegeneration, namely, the Harlequin mutant mouse. The first specific aim was to test the hypothesis …

Coupling Selection Of The Hiv- 1 Trna Primer Used For Reverse Transcription With Viral Translation And Encapsidation, Uros V. Djekic

All ETDs from UAB

HIV-1 belongs to the Retroviridae family. A hallmark of retroviral replication is the process of reverse transcription. Viral reverse transcriptase requires placement of a cellular tRNA primer onto the primer binding site (PBS) in order to initiate conversion of the viral RNA genome into a double stranded DNA copy. Mutation of the HIV-1 PBS forces the virus to utilize the non-cognate primer. Even though extensive studies have been done over the past 15 years, the mechanism of HIV-1 primer selection has yet to be completely elucidated. HIV-1 captures free tRNA during a yet undefined step in viral replication. However, our …

Protease Dysregulation: Role In Neutrophilic Inflammation In Cystic Fibrosis, Amit Gaggar

All ETDs from UAB

Cystic fibrosis (CF) is a lethal disorder characterized by abnormal epithelial ion transport; this disorder is characterized by an ongoing airway remodeling and neutrophilic inflammation. Much of the airway remodeling is due to activation of a group of enzymes known as proteases; human neutrophil elastase (HNE) is a prominent protease found in the CF airway. While specific cytokines/chemokines are well-known for their role in the inflammation seen in CF, it is unknown how the protease-rich environment in CF lung disease influences airway inflammation. Recently, our group has characterized a novel collagen-derived fragment, proline-glycine-proline (PGP), which causes neutrophil influx through mechanisms …

Protein Interaction And Cell Surface Trafficking Differences Between Wild-Type And Δf508 Cystic Fibrosis Transmembrane Conductance Regulator, Rebecca F. Goldstein

All ETDs from UAB

Cystic fibrosis (CF) is caused by mutation of one protein, the cystic fibrosis transmembrane conductance regulator (CFTR), which normally functions as a chloride channel at the apical surface of epithelial cells. The most common CFTR mutation results in the deletion of a single amino acid (phenylalanine) at position 508, which causes the protein to fold improperly. The ΔF508 CFTR is a temperature-sensitive (TS) processing mutant: At the restrictive temperature, 37°C, ΔF508 CFTR misfolds in the endoplasmic reticulum (ER) and is degraded, but at the permissive temperature, 27°C, it is “rescued” from degradation (rΔF508). In particular, rΔF508 CFTR folds correctly enough …

Interference With Hiv-1 Primer Selection By Sirna Directed To The Hiv-1 Primer Binding Site, Wenlong Han

All ETDs from UAB

The replication of Human immunodeficiency virus type 1 (HIV-1) is characterized by the process of reverse transcription, which converts the viral RNA genome into a DNA intermediate prior to integration into the host cell chromosome. The initiation of reverse transcription needs a cellular tRNA primer, which binds to a region in the viral RNA genome, designated as the primer binding site (PBS). The 18-nucleotide PBS region of HIV-1, which is complementary to the 3′ terminal 18 nucleotides of tRNALys,3, is absolutely conserved among all HIV-1. The highly conserved PBS is a very good target for HIV-1 therapy. My dissertation research …

Regulation Of The Human Heme Oxygenase-1 Gene, Thomas D. Hock

All ETDs from UAB

The heme oxygenase-1 (HO-1) gene encodes a microsomal enzyme that catalyzes the conversion of heme to carbon monoxide, Iron, and biliverdin. HO-1 transcription is induced upon a plethora of cellular stresses including heme, heavy metal exposure, hy-poxia, oxidative stress and many others. The goal of this work was to explore the molecu-lar regulation of HO-1 transcription. Four DNase 1 hypersensitive sites are detected within the HO-1 promoter extending from ~-40bp to ~-9.2kb relative to the transcription start site. Dimethylsulfate (DMS) in vivo footprinting is shown for two regulatory re-gions and reveals nine protected guanines in all. Mutational analyses indicates that …

Quantitation Of Antiretrovirals In Alternative Matrices, Chantelle Bennetto Hood

All ETDs from UAB

The human immunodeficiency virus (HIV) pandemic is a growing concern, affecting almost 40 million people worldwide. Treatment for HIV infection consists of highly active antiretroviral therapy (HAART) to block different steps in the viral lifecycle, ultimately reducing HIV RNA to undetectable levels in the plasma. However, HIV RNA can be detected in numerous reservoirs outside of the blood despite the use of HAART. Therefore, measurement of antiretroviral (ARV) drugs in other biological matrices is important to broaden our understanding of HIV transmission, the development of viral resistance with sub-optimal ARV exposure, and fetal and neonatal drug exposure. This work describes …

On The Immunological Roles Of Tlt2 And Hsh2, R Glenn King

All ETDs from UAB

The evolution of multicellular organisms necessitated the ability to detect and remove harmful parasitic microorganisms from the host. This simple requirement for self non-self discrimination has evolved in vertebrates into an elaborate system consisting of a variety of effector mechanisms to perform this process. The immune system is often described as consisting of two distinct yet complimentary components, the innate and adaptive immune systems. It is now recognized that the immune system relies on the highly coordinated interplay between a variety of cell types which cooperate to maintain the health of the organism. The work outlined in this dissertation addresses …

The Effect Of The Aml1-Eto Translocation On Cell Cycle Tumor Suppressor Gene Function, Rose Marie Ko

All ETDs from UAB

The t(8;21)(q22;q22) AML1-ETO translocation is one of the most frequent translocations in acute myeloid leukemia (AML), occurring in approximately 12% of cases. Our laboratory has generated a mouse model in which AML1-ETO is expressed in hematopoietic progenitor cells using a retroviral vector and assayed using bone marrow transplantation. Animals transplanted with AML1-ETO-expressing cells failed to develop leukemia. However, AML1-ETO promoted significant expansion of immature myeloid cells suggesting a “pre-leukemic” state that requires secondary mutations for disease progression. In addition, analysis of cell cycle kinetics in AML1-ETOexpressing myeloid progenitor cells showed that AML1- ETO slowed G1 to S phase progression compared …

Identification Of A 17-Nucleotide Splicing Enhancer In Hpv-16 L1 That Counteracts The Effect Of Multiple Hnrnp A1-Binding Splicing Silencers, Ziaomin Zhao, Joanna Fay, Stefan Schwartz, Helen Lambkin

Articles

Human papillomavirus type 16 (HPV-16) infections can in rare cases persist and cause lesions that may progress to cervical cancer. Cells in the lesions are not permissive for virus production, nor are cervical cancer cells. The intracellular environment is such that it prevents production of the highly immunogenic, viral structural proteins L1 and L2. One may speculate that inhibition of L1 and L2 expression is a prerequisite for persistence and cancer progression.We have therefore investigated how expression of HPV-16 L1 is regulated.We found that the only splice site in the HPV-16 late region, which is used to produce L1 mRNAs, …

Mutagenesis Of The Catalytic Triad Of Tissue Transglutaminase Abrogates Coeliac Disease Serum Iga Autoantibody Binding, Greg Byrne, Fergus Ryan, John Jackson, Con Feighery, Jacinta Kelly

Articles

Background and aims: Tissue transglutaminase (tTG) is an autoantigen in coeliac disease and the related disorder, dermatitis herpetiformis. The detection of autoantibodies directed against tTG is a highly specific marker of coeliac disease; however, it is unclear if there is a role for these autoantibodies in the disease process. The aim of this study was to investigate whether the catalytic triad of tTG is targeted by coeliac disease autoantibodies. Methods: A full-length wild-type recombinant tTG and a novel site-directed mutagenic variant lacking the catalytic triad were produced in Escherichia coli. Serum samples from 61 biopsy-proven coeliac disease and 10 dermatitis …

Localization And Function Of G2e3, William Samuel Brooks

All ETDs from UAB

A microarray study was performed which identified G2E3 as a novel, putative ubiquitin ligase that was both G2/M-specific in expression and down regulated at the transcriptional level following DNA damage by γ-irradiation. The initial characterization of this protein is described herein. G2E3 is composed of three PHD/RING (plant homoedomain/really interesting new gene) domains within its amino-terminal half and a carboxy-terminal HECT (homologous to E6AP carboxy-terminus) domain. G2E3 is regulated in part by its subcellular localization. The protein normally resides within the nucleoplasm of cultured cells and distinctly within the nucleolus of HeLa cells. G2E3 is a nucleo-cytoplasmic shuttling protein with …

Loss Of Pias3 Expression In Glioblastoma Multiforme Tumors:Implications For Stat-3 Activation And Gene Expression, Emily Claire Brantley

All ETDs from UAB

Glioblastoma multiforme (GBM) is the most common form of cancer in the central nervous system in adults. Because of the infiltrative and aggressive nature of GBM, current treatments including surgical resection, radiation and chemotherapy provide little benefit to patients diagnosed with this tumor. Median survival, after treatment, is less than one year. Despite advances in the basic understanding of cancer biology, this poor prognosis has remained virtually unchanged for several decades. Given the continuing difficulty of clinical treatment of GBMs, a molecular appreciation of relevant signaling pathways has grown. Signal Transducers and Activators of Transcription (STATs) function to activate gene …

Characterization Of A Novel Acetyltransferase Found Only In Pathogenic Strains Of Mycobacterium Tuberculosis, David K. Crossman

All ETDs from UAB

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is still a major threat to the human population. Roughly one third of the world population is asymptomatically infected and two million people die each year of TB. Effective treatments are available as a multi-drug regimen, but there is an ever increasing problem with the rise of multi-drug resistant strains that newer drug targets and a better understanding of how M. tuberculosis affects the host need to be elucidated. The primary target of M. tuberculosis in the human host is the macrophage where M. tuberculosis secretes virulence factors that inhibit various signal …

A Study Into The Protein/Protein Interactions Involved In Hiv-1 Capsid Assembly, Chanel Catherine Douglas

All ETDs from UAB

The aim of this work was to build an understanding of the protein/protein interactions involved in HIV-1 capsid assembly as it relates to the condensation of capsid within the virion. This was undertaken in an attempt to (i) understand how capsid subunits recognize and interact with each other, (ii) gain insight into the protein-protein interactions involved in the process, and (iii) determine if the protein-protein interactions involved in virus cap-sid assembly can be used as a target for viral inhibition. Within this dissertation you will find two approaches to this investigation. The first examines the role of electrostatics in the …

Pneumococcal Choline-Binding Protein A: Its Role In Virulence And Its Utility As A Streptococcus Pneumoniae Vaccine Antigen, David Tawayne Glover

All ETDs from UAB

Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. S. pneumoniae is a leading cause of pneumonia, meningitis, septicemia, and otitis media. Although all age groups can be affected, children and the elderly are espccially susceptible to infection. Currently there is a conjugate vaccine available for use, but this vaccine only contains capsular polysaccahride antigens from the seven most prevelant S. pneumoniae serotypes. The use of the conjugate vaccine has led to serotype shift, with more disease being caused by non-vaccine serotype bacteria. The studies presented in this dissertation identify and characterize a novel S. penumoniae vaccine candidate …

A Role For P63 In The Regulati On Of Cell Cycle Progression And Cell Death, Eric Scott Helton

All ETDs from UAB

p63 is a member of the p53 family of transcription factors that is a critical regulator of epithelial development. Studies have shown that p63 does not appear to function as a classical tumor suppressor like p53. Instead, the expression pattern of p63 in cancers suggests that p63 retains the potential to function as either a tumor suppressor or an onco-protein. Here, we provide evidence describing the transcriptional activity of the p63 isoforms and provide mechanisms whereby p63 function is regulated in a context dependent manner. Our data shows that both the ΔNp63 and TAp63 variants retain the potential to regulate …

Prostate Cancer Chemoprevention With Genistein And Resveratrol In Models Of Spontaneously Developing Prostate Cancer, Curt E. Harper

All ETDs from UAB

Prostate cancer is the second leading cause of cancer-related death among men in the United States. The goal of this research was to investigate the potential of three nutriceutical polyphenols, genistein, resveratrol, and epigallocatechin-3-gallate (EGCG), to suppress prostate cancer. Cancer chemoprevention and mechanism of action studies were carried out in transgenic models of prostate cancer. In TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model, resveratrol suppressed poorly differentiated tumors by 86%, whereas EGCG suppressed precancerous lesions, but failed to prevent late-stage prostate cancer. Agents that were chemopreventive in the TRAMP model were subsequently evaluated alone, and in combination, in the …

Primer Selection Of E. Coli Trna Lys,3 By Human Immunodeficiency Virus Type-1, Anna Mcculley

All ETDs from UAB

Human immunodeficiency virus (HIV) is the cause of acquired immunodeficiency syndrome (AIDS). HIV replication includes the notable process of reverse transcription, a conversion of RNA to DNA. Reverse transcription is initiated from a primer by a viral enzyme, reverse transcriptase. The primer, tRNALys,3, is selected from the cytoplasm of an infected cell, annealed via the 3’ terminal 18-nucleotides to the viral primer binding site (PBS), and used in a subsequent infection. The mechanism of primer selection has not been determined although numerous studies have been performed. This has been hampered by the challenge of tRNALys,3 manipulation in the cell and …

Directing Akt And Gsk3ss: Molecular Insights Into Cell Signaling And Survival, Gordon P. Meares

All ETDs from UAB

Proper regulation of survival signaling is critical for all organisms. One important signaling cascade involved in the coordinated effort to control signals influencing cell fate is the phosphatidylinositol 3-kinase (PI3K)-Akt-glycogen synthase kinase 3β (GSK3β) signaling cascade. Following activation by growth factors the PI3K-Akt pathway promotes cell survival and, cell death is facilitated following inhibition of Akt. Many factors influence the function of the Akt-GSK3β signaling dyad, including phosphorylation, protein complex formation and subcellular localization. Previous work had demonstrated that the 90kDa heat shock protein, HSP90, directly binds and stabilizes Akt. Furthermore, several heat shock proteins including HSP90 and HSP105 can …

Regulation Of Vertebrate Gastrulation By Erbb Signaling, Shuyi Nie

All ETDs from UAB

ErbB receptor tyrosine kinases have long been implicated in cancer formation and progression by regulating cell division, migration, and survival. ErbBs are also essential in multiple processes during invertebrate development; however, their activities during vertebrate embryogenesis are not well understood. For functional characterization of ErbB signaling during vertebrate development, frog model Xenopus laevis was used in our studies. The expression pattern and the general activities of ErbB receptors during early frog development were first analyzed and results shown that ErbBs regulate gastrulation, somite organization and head patterning. As gastrulation is the first major morphogenetic event in vertebrate development, I focused …

Surveying The Chromosomal Supercoiling Levels In Rapidly Growing Wild Type And Gyrase Mutant Strains Of Salmonella Enterica Serovar Typhimurium With Γδ Resolvase-Mediated Recombination Assay, Zhenhua Pang

All ETDs from UAB

A gyrase mutant strain (gyrB652) has severe growth defect at 42°C. The survival at high temperature is dependent on DNA repair proteins. The purified mutant gyrase was assayed for supercoiling acitivity and quinolone-induced DNA cleavage activity. The results suggested that the mutant enzyme is not temperature-sensitive, but has slower kinetics than the wild type gyrase. The DNA supercoiling levels at multiple chromosomal loci in exponential phase cells were monitored with γδ resolvase-mediated recombination assay. The wild type cells showed homogenous supercoiling levels throughout most of the chromosome. But the superhelicity at dif locus was significantly lower than the other loci. …

Trafficking Of Hantaviral Nucleocapsid Proteins, Harish N. Ramanathan

All ETDs from UAB

Hantaviruses are enveloped, negative-sense RNA viruses belonging to genus Hantavirus, within the family Bunyaviridae. Hantaviruses include many serious human pathogens and are classified as Old and New World based on the geographic distribution of rodent reservoirs and their ability to in induce distinct illnesses in humans. Currently there are no reservoirs known for hantaviruses other than the rodents. Human transmission of hantaviruses occurs via inhalation of aerosolized rodent excreta leading to hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). Hantavirus genome consists of small (S), medium (M) and large (L) segments that encode nucleocapsid (N) protein, two …

The Role Of Complement In Experimental Autoimmune Uveitis, Russell W. Read

All ETDs from UAB

The complement system has been increasingly implicated in the pathophysiology of autoimmune disease. Complement expression in the normal human eye had not been previously completely defined. We performed immunohistochemical studies for membrane complement proteins in normal human retina to provide a baseline for future studies. We found expression of the anaphylatoxin receptors, CD55, and CD59 in the inner retina and CD46 in a polarized fashion on the retinal pigment epithelium. Previous studies in uveitis have shown activated fragments of complement in human eyes with uveitis and animal models have shown an effect on disease by complement depletion with cobra venom …

Pathogenesis And Therapeutic Potential Of Plasmacytoid Dendritic Cells In Siv/Shiv-Infected Macaques, R Keith Reeves

All ETDs from UAB

Plasmacytoid dendritic cells (pDCs) are among the first responders during acute viral infections and are the primary producers of IFN-α, a cytokine known to inhibit viral replication and to activate natural killer (NK) cells. In HIV patients pDCs are decreased in number, are dysfunctional, and can harbor HIV-1 proviruses. However, since the time of transmission is usually unknown, pDC-virus interactions immediately after exposure to HIV remain unclear. Using the SIV/SHIV-macaque model, we showed that an acute and sustained loss of blood pDCs occurred during SIVmac239 infections, and when compared to those from naïve controls, pDCs were also significantly reduced in …

The Characterization Of The Subcellular Localization Of Bile Acid Coa: N-Acyltransferase, Nathan Allen Styles

All ETDs from UAB

The liver plays a central role in metabolism. It controls protein metabolism through deamination and transamination of amino acids, removal of ammonia through urea synthesis, synthesis of non-essential amino acids and synthesis of the majority of plasma proteins such as albumin. The liver regulates blood glucose levels through glyconeogenesis and glyconeolysis of glycogen, as well as gluconeogenesis from amino acids. It regulates fat metabolism through oxidation of triglycerides and fatty acids, as well as synthesis of cholesterol, lipoproteins, and phospholipids. Furthermore, the liver is the only site of formation of bile acids and their conjugates, physiologically important compounds that solubilize …

Bacillus Anthracis Spore-Host Interactions, Melissa K. Swiecki

All ETDs from UAB

The use of Bacillus anthracis as a bioweapon depends on the dispersal of its spores into the environment, entrance into the body, spore uptake by human host cells, germination of the spores in the host and the pathological consequences of the virulence factors produced by the vegetative cells. Prior to 2001, very little was known about the mechanisms of spore entry into the host, including targeting cell types at airway, digestive and skin surfaces, potential spore receptors on these cells and spore encounters with cellular and humoral elements of the innate and adaptive immune systems. To this end, we have …