A Closer Look: Deep South Has The Highest Hiv-Related Death Rates In The United States, Susan S. Reif, Donna Safley, Carolyn Mcallaster

Faculty Scholarship

No abstract provided.

Role Of Antibody Isotypes In Providing Passive Protection Against Ricin Toxin, Ipneet Kaur Dhaliwal

Legacy Theses & Dissertations (2009 - 2024)

Ricin toxin is a glycoprotein produced by the castor bean plant, Ricinus communis. Ricin is an extraordinarily potent inducer of cell death and inflammation, especially following inhalation. The toxin’s enzymatic subunit (RTA) is transported via retrograde transport into the cytoplasm of mammalian cells by the toxin’s B subunit (RTB). Once in the cytoplasm, RTA inactivates ribosomes through cleavage of ribosomal RNA. In this study, I characterized a ricin-specific monoclonal IgA antibody (mAb) known as 23D7. I confirmed that 23D7 reacts with RTA and is effective at neutralizing ricin in a Vero cell cytotoxicity assay in vitro. To localize the epitope …

Francisella Tularensis Catalase Restricts Immune Function By Impairing Trpm2 Channel Activity, Nicole Lynn Flaherty

Legacy Theses & Dissertations (2009 - 2024)

As an innate defense mechanism, macrophages produce reactive species that weaken pathogens and serve as secondary messengers to modify signaling responses involved in immune function. The gram-negative bacterium F. tularensis utilizes its antioxidant armature to limit the host immune response but the mechanism behind this suppression has not been defined. Here we establish that F. tularensis limits Ca2+ entry thereby limiting actin reorganization and IL-6 production in a redox-dependent fashion. Wild-type (LVS) or catalase deficient F. tularensis (∆katG) show distinct profiles in their H2O2 scavenging capacity, 1 pM/sec and 0.015 pM/sec, respectively. Murine alveolar macrophages infected with ∆katG display distinct …

A Single Vertebrate Dna Virus Protein Disarms Invertebrate Immunity To Rna Virus Infection, Don B. Gammon, Sophie Duraffour, Daniel K. Rozelle, Heidi Hehnly, Rita Sharma, Michael E. Sparks, Cara C. West, Ying Chen, James J. Moresco, Graciela Andrei, John H. Connor, Darryl Conte Jr., Dawn E. Gundersen-Rindal, William L. Marshall, John R. Yates, Neal S. Silverman, Craig C. Mello

Neal Silverman

Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. We found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), are completely restricted in their replication after entry into Lepidopteran cells. This restriction is overcome when cells are co-infected with vaccinia virus (VACV), a vertebrate DNA virus. Using RNAi screening, we show that Lepidopteran RNAi, Nuclear Factor-kappaB, and ubiquitin-proteasome pathways restrict RNA virus infection. Surprisingly, a highly conserved, uncharacterized VACV protein, A51R, can partially overcome this virus restriction. We show that A51R is also critical for VACV replication in vertebrate cells …

Gut Microbiota-Derived Short-Chain Fatty Acids, T Cells, And Inflammation, Chang Kim, Jeongho Park, Myunghoo Kim

Department of Comparative Pathobiology Faculty Publications

T cells are central players in the regulation of adaptive immunity and immune tolerance. In the periphery, T cell differentiation for maturation and effector function is regulated by a number of factors. Various factors such as antigens, co-stimulation signals, and cytokines regulate T cell differentiation into functionally specialized effector and regulatory T cells. Other factors such as nutrients, micronutrients, nuclear hormones and microbial products provide important environmental cues for T cell differentiation. A mounting body of evidence indicates that the microbial metabolites short-chain fatty acids (SCFAs) have profound effects on T cells and directly and indirectly regulate their differentiation. We …

Bacterial Rna:Dna Hybrids Are Activators Of The Nlrp3 Inflammasome, Sivapriya Kailasan Vanaja, Vijay A. K. Rathinam, Maninjay K. Atianand, Parisa Kalantari, Brian M. Skehan, Katherine A. Fitzgerald, John M. Leong

Katherine A. Fitzgerald

Enterohemorrhagic Escherichia coli (EHEC) is an extracellular pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. The proinflammatory cytokine, interleukin-1beta, has been linked to hemolytic uremic syndrome. Here we identify the nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3) inflammasome as an essential mediator of EHEC-induced IL-1beta. Whereas EHEC-specific virulence factors were dispensable for NLRP3 activation, bacterial nucleic acids such as RNA:DNA hybrids and RNA gained cytosolic access and mediated inflammasome-dependent responses. Consistent with a direct role for RNA:DNA hybrids in inflammasome activation, delivery of synthetic EHEC RNA:DNA hybrids into the cytosol triggered NLRP3-dependent responses, …

Dual Engagement Of The Nlrp3 And Aim2 Inflammasomes By Plasmodium-Derived Hemozoin And Dna During Malaria, Parisa Kalantari, Rosane B. Deoliveira, Jennie Chan, Yolanda Corbett, Vijay A. K. Rathinam, Andrea Stutz, Eicke Latz, Ricardo T. Gazzinelli, Douglas T. Golenbock, Katherine A. Fitzgerald

Katherine A. Fitzgerald

Hemozoin (Hz) is the crystalline detoxification product of hemoglobin in Plasmodium-infected erythrocytes. We previously proposed that Hz can carry plasmodial DNA into a subcellular compartment that is accessible to Toll-like receptor 9 (TLR9), inducing an inflammatory signal. Hz also activates the NLRP3 inflammasome in primed cells. We found that Hz appears to colocalize with DNA in infected erythrocytes, even before RBC rupture or phagolysosomal digestion. Using synthetic Hz coated in vitro with plasmodial genomic DNA (gDNA) or CpG oligodeoxynucleotides, we observed that DNA-complexed Hz induced TLR9 translocation, providing a priming and an activation signal for inflammasomes. After phagocytosis, Hz and …

Malaria-Induced Nlrp12/Nlrp3-Dependent Caspase-1 Activation Mediates Inflammation And Hypersensitivity To Bacterial Superinfection, Marco A. Ataide, Warrison A. Andrade, Dario S. Zamboni, Donghai Wang, Maria Do Carmo Souza, Bernardo S. Franklin, Samir Elian, Flaviano S. Martins, Dhelio Pereira, George W. Reed, Katherine A. Fitzgerald, Douglas T. Golenbock, Ricardo T. Gazzinelli

Katherine A. Fitzgerald

Cyclic paroxysm and high fever are hallmarks of malaria and are associated with high levels of pyrogenic cytokines, including IL-1beta. In this report, we describe a signature for the expression of inflammasome-related genes and caspase-1 activation in malaria. Indeed, when we infected mice, Plasmodium infection was sufficient to promote MyD88-mediated caspase-1 activation, dependent on IFN-gamma-priming and the expression of inflammasome components ASC, P2X7R, NLRP3 and/or NLRP12. Pro-IL-1beta expression required a second stimulation with LPS and was also dependent on IFN-gamma-priming and functional TNFR1. As a consequence of Plasmodium-induced caspase-1 activation, mice produced extremely high levels of IL-1beta upon a second …

Hcpe, A Potential Immuno-Modulatory Protein From Helicobacter Pylori That Is Dependent On The Disulfide Bond Protein Dsbhp, Jeff Lester

Electronic Thesis and Dissertation Repository

H. pylori is a human gastric pathogen that colonizes ~ 50% of the world’s population. It can cause gastritis, gastric or duodenal ulcers and also gastric cancer. H. pylori produces Helicobacter cysteine rich protein HcpE, a secreted protein which may play a role in virulence. In this study we show that HcpE is secreted in the culture supernatant both as a soluble protein and in association with outer membrane vesicles, and may play a role in the modulation of H. pylori inflammatory responses. We identified that Dsb_HP is necessary for HcpE production and secretion in H. pylori, and …

The Role Of Dual Specificity Phosphatase -11 In Innate And Adaptive Immune Responses, Kalyan Chakravarthy Nallaparaju

Dissertations & Theses (Open Access)

THE ROLE OF DUAL SPECIFICITY PHOSPHATASE -11 IN INNATE AND ADAPTIVE IMMUNE RESPONSES

Kalyan Chakravarthy Nallaparaju, M.S.

Supervisory Professor: Chen Dong, Ph.D.

Dual-specificity phosphatases (DUSPs) constitute a subfamily of protein tyrosine phosphatases characterized by their ability to dephosphorylate both phosphotyrosine and phosphoserine/phosphothreonine residues within a substrate, typically among members of the MAP kinase family. DUSPs have been shown to play a critical role in the regulation of various cellular processes including signal transduction, cell cycle regulation and cellular proliferation via modulation of MAP kinase activities. Also, many members of this family have been demonstrated to be potent immune regulators. …

The Pathological Effects Of Ccr2+ Inflammatory Monocytes Are Amplified By An Ifnar1-Triggered Chemokine Feedback Loop In Highly Pathogenic Influenza Infection, Sue-Jane Lin, Ming Lo, Rei-Lin Kuo, Shin-Ru Shih, David M. Ojcius, Jean Lu, Chien-Kuo Lee, Hui-Chen Chen, Meei Yun Lin, Chuen-Miin Leu, Chia-Ni Lin, Ching-Hwa Tsai

All Dugoni School of Dentistry Faculty Articles

Background: Highly pathogenic influenza viruses cause high levels of morbidity, including excessive infiltration of leukocytes into the lungs, high viral loads and a cytokine storm. However, the details of how these pathological features unfold in severe influenza infections remain unclear. Accumulation of Gr1 + CD11b + myeloid cells has been observed in highly pathogenic influenza infections but it is not clear how and why they accumulate in the severely inflamed lung. In this study, we selected this cell population as a target to investigate the extreme inflammatory response during severe influenza infection.

Results: We established H1N1 IAV-infected mouse models using …

The Impact Of Polio Eradication On Routine Immunization And Primary Health Care: A Mixed-Methods Study, Svea Closser, Kelly Cox, Thomas M. Parris, R Matthew Landis, Judith Justice, Ranjani Gopinath, Kenneth Maes, Hailom Banteyerga Amaha, Ismaila Zango Mohammed, Rashid Jooma

Section of Neurosurgery

Background: After 2 decades of focused efforts to eradicate polio, the impact of eradication activities on health systems continues to be controversial. This study evaluated the impact of polio eradication activities on routine immunization (RI) and primary healthcare (PHC).
Methods: Quantitative analysis assessed the effects of polio eradication campaigns on RI and maternal healthcare coverage. A systematic qualitative analysis in 7 countries in South Asia and sub-Saharan Africa assessed impacts of polio eradication activities on key health system functions, using data from interviews, participant observation, and document review.
Results: Our quantitative analysis did not find compelling evidence of widespread and …

Characterization Of Severe Fever With Thrombocytopenia Syndrome In Rural Regions Of Zhejiang, China, Lei Zhang, Ling Ye, David M. Ojcius, Xiuyu Lou, Chengwei Wang, Cen Feng, Yi Sun, Zhongfa Wang, Shibo Li, Yanjun Zhang

All Dugoni School of Dentistry Faculty Articles

Severe fever with thrombocytopenia syndrome virus (SFTSV) infections have recently been found in rural regions of Zhejiang. A severe fever with thrombocytopenia syndrome (SFTS) surveillance and sero-epidemiological investigation was conducted in the districts with outbreaks. During the study period of 2011–2014, a total of 51 SFTSV infection cases were identified and the case fatality rate was 12% (6/51). Ninety two percent of the patients (47/51) were over 50 years of age, and 63% (32/51) of laboratory confirmed cases occurred from May to July. Nine percent (11/120) of the serum samples from local healthy people without symptoms were found to be …

Human Papillomavirus And The Gardasil Vaccine: Medicalization And The Gendering Of Bodies And Bodily Risk, Lauren Camara

Laurier Undergraduate Journal of the Arts

No abstract provided.

A Cytoplasmic Rna Virus Generates Functional Viral Small Rnas And Regulates Viral Ires Activity In Mammalian Cells, Kuo-Feng Weng, Chuan-Tien Hung, Po-Ting Hsieh, Mei-Ling L. Li, Guang-Wu Chen, Yu-An Kung, Peng-Nien Huang, Rei-Lin Kuo, Li-Lien Chen, Jing-Yi Lin, Robert Yung-Liang Wang, Shu-Jen Chen, Petrus Tang, Jim-Tong Horng, Hsing-I Huang, Jen-Ren Wang, David M. Ojcius, Gary Brewer, Shin-Ru Shih

All Dugoni School of Dentistry Faculty Articles

The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (>10⁵ copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced …

The Role Of Superantigens During Staphylococcus Aureus Nasal Colonization And Infection, Stacey Xu

Electronic Thesis and Dissertation Repository

Superantigens (SAgs) are potent toxins produced by bacteria such as Staphylococcus aureus that function to overactivate T cells resulting in massive cytokine production and immune activation. Despite decades of research on the structure and function of these proteins, as well as their role in severe diseases such as toxic shock syndrome, the question as to why strains of S. aureus produce SAgs and the role that they play in the life cycle of these bacteria remains unanswered. The contribution of SAgs towards pathogenicity and bacterial survival in vivo were assessed using isogenic SAg deletion knockouts in conjunction with SAg-sensitive humanized …

Functional Role Of Zebrafish Tlr Proteins, Carol H. Kim

University of Maine Office of Research Administration: Grant Reports

Project summary.

Influenza virus infections lead to significant illness, mortality, and social disruption worldwide. Herein, the first studies establishing the zebrafish as a model for human influenza infection are presented and it is shown that influenza infection proceeds and can be resolved through similar mechanisms in zebrafish and humans (Gabor, et al.). Our laboratory has previously characterized a fish rhabdovirus infection model in the zebrafish (Phelan, et al.).

Human Ezrin-Moesin-Radixin Proteins Modulate Hepatitis C Virus Infection, Terence Bukong, Karen Kodys, Gyongyi Szabo

Gyongyi Szabo

Host cytoskeletal proteins of the ezrin-moesin-radixin (EMR) family have been shown to modulate single-stranded RNA virus infection through regulating stable microtubule formation. Antibody engagement of CD81, a key receptor for hepatitis C virus (HCV) entry, induces ezrin phosphorylation. Here we tested the role of EMR proteins in regulating HCV infection and explored potential therapeutic targets. We show that HCV E2 protein induces rapid ezrin phosphorylation and its cellular redistribution with F-actin by way of spleen tyrosine kinase (SYK). Therapeutically blocking the functional roles of SYK or F-actin reorganization significantly reduced Huh7.5 cell susceptibility to HCV J6/JFH-1 infection. Using gene regulation, …

Human Type 2 Myeloid Dendritic Cells Produce Interferon-Lambda And Amplify Interferon-Alpha In Response To Hepatitis C Virus Infection, Shuye Zhang, Karen Kodys, Kui Li, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND and AIMS: The type III interferons (IFN-lambdas: interleukin [IL]-28a, IL-28b, and IL-29) have important roles in hepatitis C virus (HCV) infection, but little is understood about what cells produce these cytokines or how production is activated. We investigated whether human immune cells recognize HCV-infected cells and respond by producing IFN-lambda. METHODS: We cultured healthy human peripheral blood mononuclear cells (PBMCs) with different populations of immune cells and Japanese fulminant hepatitis-1 (JFH-1) HCV-infected Huh7.5 (cell culture-derived HCV particles [HCVcc]/Huh7.5) cells. RESULTS: Human PBMCs recognized HCVcc/Huh7.5 cells and responded by producing IFN-alpha, IFN-gamma, and IFN-lambda. A rare subset of myeloid dendritic …

Innate Immune Cell Networking In Hepatitis C Virus Infection, Banishree Saha, Gyongyi Szabo

Gyongyi Szabo

Persistent viral infection, such as HCV infection, is the result of the inability of the host immune system to mount a successful antiviral response, as well as the escape strategies devised by the virus. Although each individual component of the host immune system plays important roles in antiviral immunity, the interactive network of immune cells as a whole acts against the virus. The innate immune system forms the first line of host defense against viral infection, and thus, virus elimination or chronic HCV infection is linked to the direct outcome of the interactions between the various innate immune cells and …