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Articles 151 - 180 of 584
Full-Text Articles in Medical Microbiology
Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte
Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte
Electronic Theses and Dissertations
Chlamydia is the most common bacterial sexually transmitted infection in the United States and worldwide. It often goes unnoticed due to lack of symptoms and left untreated it can ascend the female genital tract to cause sequelae like pelvic inflammatory disease and irreversible tubal infertility. In reproductive-aged women, female sex hormones estrogen (E2) and progesterone (P4) concentrations fluctuate during the menstrual cycle and are influenced by hormonal contraceptives and hormone replacement therapy. E2 and P4 influence genital Chlamydia infection in women and mice, but these multifactorial interactions are not entirely mapped out. The complex interplay of E2 and P4 with …
Moerv29 Promotes Apoplastic Effector Secretion Contributing To Virulence Of The Rice Blast Fungus Magnaporthe Oryzae, Bin Qian, Xiaotong Su, Ziyuan Ye, Xinyu Liu, Muxing Liu, Danyu Shen, Han Chen, Haifeng Zhang, Ping Wang, Zhengguang Zhang
Moerv29 Promotes Apoplastic Effector Secretion Contributing To Virulence Of The Rice Blast Fungus Magnaporthe Oryzae, Bin Qian, Xiaotong Su, Ziyuan Ye, Xinyu Liu, Muxing Liu, Danyu Shen, Han Chen, Haifeng Zhang, Ping Wang, Zhengguang Zhang
School of Medicine Faculty Publications
During plant-pathogenic fungi and host plants interactions, numerous pathogen-derived proteins are secreted resulting in the activation of the unfolded protein response (UPR) pathway. For efficient trafficking of secretory proteins, including those important in disease progression, the cytoplasmic coat protein complex II (COPII) exhibits a multifunctional role whose elucidation remains limited. Here, we discovered that the COPII cargo receptor MoErv29 functions as a target of MoHac1, a previously identified transcription factor of the UPR pathway. In Magnaporthe oryzae, deletion of MoERV29 severely affected the vegetative growth, conidiation and biotrophic invasion of the fungus in susceptible rice hosts. We demonstrated that MoErv29 …
The Role Of The Filifactor Alocis Hypothetical Protein Fa519 In Oxidative Stress Resistance, Ezinne Rebecca Aja
The Role Of The Filifactor Alocis Hypothetical Protein Fa519 In Oxidative Stress Resistance, Ezinne Rebecca Aja
Loma Linda University Electronic Theses, Dissertations & Projects
Filifactor alocis, a fastidious, Gram-positive, obligate anaerobic bacterium, is a newly appreciated member of the periodontal community, which is now proposed to be a diagnostic indicator of periodontal disease. Its pathogenic characteristics are highlighted by its ability to survive in the oxidative-stress rich environment of the periodontal pocket and to significantly alter the microbial community dynamics by forming biofilms and interacting with several oral bacteria. Currently, there is incomplete information on the pathogenic mechanism(s) and a possible dynamic functional role of F. alocis in the dysbiotic microbial community. Because the stress response of this bacterium to the oxidative environment …
Interleukin-10 Suppression Enhances T-Cell Antitumor Immunity And Responses To Checkpoint Blockade In Chronic Lymphocytic Leukemia., J R Rivas, Y Liu, S S Alhakeem, J M Eckenrode, F Marti, J P Collard, Y Zhang, K A Shaaban, N Muthusamy, G C Hildebrandt, L Chen, J S Thorson, M Leggas, Subbarao Bondada
Interleukin-10 Suppression Enhances T-Cell Antitumor Immunity And Responses To Checkpoint Blockade In Chronic Lymphocytic Leukemia., J R Rivas, Y Liu, S S Alhakeem, J M Eckenrode, F Marti, J P Collard, Y Zhang, K A Shaaban, N Muthusamy, G C Hildebrandt, L Chen, J S Thorson, M Leggas, Subbarao Bondada
Microbiology, Immunology, and Molecular Genetics Faculty Publications
T-cell dysfunction is a hallmark of B-cell Chronic Lymphocytic Leukemia (CLL), where CLL cells downregulate T-cell responses through regulatory molecules including programmed death ligand-1 (PD-L1) and Interleukin-10 (IL-10). Immune checkpoint blockade (ICB) aims to restore T-cell function by preventing the ligation of inhibitory receptors like PD-1. However, most CLL patients do not respond well to this therapy. Thus, we investigated whether IL-10 suppression could enhance antitumor T-cell activity and responses to ICB. Since CLL IL-10 expression depends on Sp1, we utilized a novel, better tolerated analogue of the Sp1 inhibitor mithramycin (MTM
Output Consistency Scale To Standardize Ostomate Output Description In Clinical Practice And Studies, Lisa Whisenhunt, Linda Xu, Fan Yang, Jacques Izard
Output Consistency Scale To Standardize Ostomate Output Description In Clinical Practice And Studies, Lisa Whisenhunt, Linda Xu, Fan Yang, Jacques Izard
Food for Health: Publications
Stool descriptors have become popular due to the large diffusion of the Bristol Stool Form Scale (BSFS) via clinical studies, clinical trials, and social media. The applications have been numerous and centered around standardization of terminology that can be used by health care professionals and patients alike, as well as individuals interested in their wellness and the associated partners in the wellness industry. For a portion of the population, the digestive content is rerouted to an external manufactured pouch or bag, making the use of the BSFS visual descriptors of stool difficult. From day one post-resection surgery, ostomates are challenged …
Chemotherapy-Induced Cognitive Impairment: Focus On The Intersection Of Oxidative Stress And Tnfα., Nicole G Rummel, Luksana Chaiswing, Subbarao Bondada, Daret K St Clair, D Allan Butterfield
Chemotherapy-Induced Cognitive Impairment: Focus On The Intersection Of Oxidative Stress And Tnfα., Nicole G Rummel, Luksana Chaiswing, Subbarao Bondada, Daret K St Clair, D Allan Butterfield
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Chemotherapy-induced cognitive impairment (CICI) has been observed in a large fraction of cancer survivors. Although many of the chemotherapeutic drugs do not cross the blood-brain barrier, following treatment, the structure and function of the brain are altered and cognitive dysfunction occurs in a significant number of cancer survivors. The means by which CICI occurs is becoming better understood, but there still remain unsolved questions of the mechanisms involved. The hypotheses to explain CICI are numerous. More than 50% of FDA-approved cancer chemotherapy agents are associated with reactive oxygen species (ROS) that lead to oxidative stress and activate a myriad of …
Assesment Of Antibiotic Resistant Gene Expression In Clinical Isolates Of Pseudomonas Aeruginosa, Dustin Esmond
Assesment Of Antibiotic Resistant Gene Expression In Clinical Isolates Of Pseudomonas Aeruginosa, Dustin Esmond
Biology Theses
Increasing prevalence of nosocomial infections by antimicrobial resistant pathogens resulting in higher mortality rates and financial burden is of great concern. Pseudomonas aeruginosa represents one of six highly virulent “ESKAPE” pathogens that exhibit considerable intrinsic drug resistance as well as mechanisms for acquiring further resistance. As many of these mechanisms are regulated through gene expression, we sought to identify regulatory strategies and patterns at play in 23 clinical isolates collected from Baku, Azerbaijan and Tyler, Texas, USA. Real-time quantitative polymerase chain reaction was performed on six gene targets implicated in resistance and contrasted with antibiotic phenotypes. We found AmpC cephalosporinase …
The Sulfur Microbial Diet And Risk Of Colorectal Cancer By Molecular Subtypes And Intratumoral Microbial Species In Adult Men, Daniel R. Sikavi, Long H. Nguyen, Koichiro Haruki, Tomotaka Ugai, Wenjie Ma, Dong D. Wang, Kelsey N. Thompson, Yan Yan, Tobyn Branck, Jeremy E. Wilkinson, Naohiko Akimoto, Rong Zhong, Mai Chan Lau, Kosuke Mima, Keisuke Kosumi, Teppei Morikawa, Eric B. Rimm, Wendy S. Garrett, Jacques Izard, Yin Cao, Mingyang Song, Curtis Huttenhower, Shuji Ogino, Andrew T. Chan
The Sulfur Microbial Diet And Risk Of Colorectal Cancer By Molecular Subtypes And Intratumoral Microbial Species In Adult Men, Daniel R. Sikavi, Long H. Nguyen, Koichiro Haruki, Tomotaka Ugai, Wenjie Ma, Dong D. Wang, Kelsey N. Thompson, Yan Yan, Tobyn Branck, Jeremy E. Wilkinson, Naohiko Akimoto, Rong Zhong, Mai Chan Lau, Kosuke Mima, Keisuke Kosumi, Teppei Morikawa, Eric B. Rimm, Wendy S. Garrett, Jacques Izard, Yin Cao, Mingyang Song, Curtis Huttenhower, Shuji Ogino, Andrew T. Chan
Department of Food Science and Technology: Faculty Publications
Introduction: We recently described the sulfur microbial diet, a pattern of intake associated with increased gut sulfur-metabolizing bacteria and incidence of distal colorectal cancer (CRC). We assessed whether this risk differed by CRC molecular subtypes or presence of intratumoral microbes involved in CRC pathogenesis (Fusobacterium nucleatum and Bifidobacterium spp.).
Methods: We performed Cox proportional hazards modeling to examine the association between the sulfur microbial diet and incidence of overall and distal CRC by molecular and microbial subtype in the Health Professionals Follow-Up Study (1986-2012).
Results: We documented 1,264 incident CRC cases among 48,246 men, approximately 40% …
Effect Of Serine-Dipeptide Bacterial Lipid Treatment On Gene Expression In Hepg2 Liver Cells, Shaharia Ferdus
Effect Of Serine-Dipeptide Bacterial Lipid Treatment On Gene Expression In Hepg2 Liver Cells, Shaharia Ferdus
Honors Scholar Theses
While greater abundances of Bacteroidetes are associated with better health outcomes, this phylum is a major producer of serine-dipeptide lipids, which are thought to promote inflammation via Tolllike receptor (TLR) stimulation. Lipid 654 (L-654) is one class of serine-dipeptide lipids that has been isolated from arterial plaques and is thought to contribute to atherogenesis. Recent evidence shows that not only does long-term L-654 exposure attenuate atherosclerosis, it also significantly reduces hepatic lipid levels and markers of inflammation in mice. To better understand the impact on the human liver, L-654 was administered to HepG2 hepatocytes at concentrations of 0.5 μg/mL or …
Identification Of The E3 Ligase That Directs The Degradation Of Proteins That Control Cell Fate Decisions In Yeast, Prasanna Tati, Stephen D Willis, Katrina F. Cooper
Identification Of The E3 Ligase That Directs The Degradation Of Proteins That Control Cell Fate Decisions In Yeast, Prasanna Tati, Stephen D Willis, Katrina F. Cooper
Rowan-Virtua Research Day
The ubiquitin–proteasome system (UPS) and autophagy pathways are distinct, highly conserved proteolytic systems that play important roles in maintaining cellular homeostasis in response to environmental cues [1]. The goal of this project is to identify the E3 ligase that mediates the degradation of cyclin C following nitrogen starvation in yeast using quantitative Western blot analysis of cyclin C-myc following nitrogen starvation in mutants of known Ubc4/5 interacting E3 ligases. No potential E3 ligases were identified as stable after 4 hours of nitrogen starvation, suggesting redundancy in function.
Developing A Microdialysis Sampling-Based Biofilm/Macrophage Co-Culture Model, Alda Diaz Perez
Developing A Microdialysis Sampling-Based Biofilm/Macrophage Co-Culture Model, Alda Diaz Perez
Graduate Theses and Dissertations
The host immune system and bacterial cells are known to interact during the human lifetime. Bacteria secrete a wide variety of signaling molecules, known as quorum sensing (QSC) molecules, that modulate the host immune system. While immune-biofilm interactions involve this chemical signaling network, the mechanisms through which this occurs are not well understood. This work aimed to develop a new method that can be used not only in vitro settings but also in vivo. The microdialysis sampling technique has widely been used in in vitro and in vivo settings in humans, mice, and rats for the collection of neuropeptides, cytokines, …
A Novel Application Of Galleria Mellonella Larvae To Study Pathogenesis Of Rickettsia Rickettsii Infection, Jacob M. Jones
A Novel Application Of Galleria Mellonella Larvae To Study Pathogenesis Of Rickettsia Rickettsii Infection, Jacob M. Jones
Honors College Theses
Rickettsia are obligate intracellular tick-borne bacteria that cause acute undifferentiated febrile illness accompanied by headache, malaise, myalgias, and disseminated endothelial infection. Immune responses to Rickettsia and pathogenesis of rickettsioses are not fully understood. Current work with Rickettsia is limited to vertebrate models that are strictly regulated and have low throughput. Since the innate immune system of vertebrates retains striking similarities with the immune response in insects, invertebrates are being used to study host responses to various pathogens. The purpose of this study was to evaluate if larvae of the greater wax moth Galleria mellonella (GML) can be used as an …
3d Printing Of Human Microbiome Constituents To Understand Spatial Relationships And Shape Parameters In Bacteriology, Jacques Izard, Teklu Kuru Gerbaba, Shara R. P. Yumul
3d Printing Of Human Microbiome Constituents To Understand Spatial Relationships And Shape Parameters In Bacteriology, Jacques Izard, Teklu Kuru Gerbaba, Shara R. P. Yumul
Department of Food Science and Technology: Faculty Publications
Effective laboratory and classroom demonstration of microbiome size and shape, diversity, and ecological relationships is hampered by a lack of high-resolution, easy-to-use, readily accessible physical or digital models for use in teaching. Three-dimensional (3D) representations are, overall, more effective in communicating visuospatial information, allowing for a better understanding of concepts not directly observable with the unaided eye. Published morphology descriptions and microscopy images were used as the basis for designing 3D digital models, scaled at 20,000×, using computer-aided design software (CAD) and generating printed models of bacteria on mass-market 3D printers. Sixteen models are presented, including rod-shaped, spiral, flask-like, vibroid, …
When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki
When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki
Publications and Research
Vibrio cholerae, the causative agent of the diarrheal disease cholera, is a microbe capable of inhabiting two different ecosystems: chitinous surfaces in brackish, estuarine waters and the epithelial lining of the human gastrointestinal tract. V. cholerae defends against competitive microorganisms with a contact-dependent, contractile killing machine called the type VI secretion system (T6SS) in each of these niches. The T6SS resembles an inverted T4 bacteriophage tail and is used to deliver toxic effector proteins into neighboring cells. Pandemic strains of V. cholerae encode a unique set of T6SS effector proteins, which may play a role in pathogenesis or pandemic …
Piglet Immunization With A Spike Subunit Vaccine Enhances Disease By Porcine Epidemic Diarrhea Virus, Jieshi Yu, Chithra Sreenivasan, Tirth Uprety, Rongyuan Gao, Chen Huang, Ella J. Lee, Steven Lawson, Julie Nelson, Jane Christopher-Hennings, Radhey S. Kaushik, Eric Nelson, Diego G. Diel, Ben M. Hause, Feng Li, Dan Wang
Piglet Immunization With A Spike Subunit Vaccine Enhances Disease By Porcine Epidemic Diarrhea Virus, Jieshi Yu, Chithra Sreenivasan, Tirth Uprety, Rongyuan Gao, Chen Huang, Ella J. Lee, Steven Lawson, Julie Nelson, Jane Christopher-Hennings, Radhey S. Kaushik, Eric Nelson, Diego G. Diel, Ben M. Hause, Feng Li, Dan Wang
Maxwell H. Gluck Equine Research Center Faculty Publications
Immunization with an insect cell lysate/baculovirus mixture containing recombinant porcine epidemic diarrhea virus (PEDV) spike protein induced high levels of neutralizing antibodies in both mice and piglets. However, immunization of piglets with this vaccine resulted in enhancement of disease symptoms and virus replication in vaccine recipients exposed to PEDV challenge. Thus, these observations demonstrate a previously unrecognized challenge of PEDV vaccine research, which has important implications for coronavirus vaccine development.
Pseudomonas Aeruginosa Vaccine Development Using Dual-Species Whole Cell And Subunit Vaccines, Catherine Bell Blackwood
Pseudomonas Aeruginosa Vaccine Development Using Dual-Species Whole Cell And Subunit Vaccines, Catherine Bell Blackwood
Graduate Theses, Dissertations, and Problem Reports (ETD)
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen which can cause severe, recurrent, and chronic infections. The pathogen is highly adaptable, and pneumonia caused by it is associated with high morbidity and mortality, especially in individuals with the genetic disorder cystic fibrosis. Antibiotic resistance amongst clinical isolates of P. aeruginosa is steadily increasing, and multi-drug resistant strains are prevalent. There is currently no vaccine available for commercial use against P. aeruginosa. For these reasons, we sought to understand the immunity to P. aeruginosa induced by whole cell vaccination and identify antigens for development of future subunit vaccines. In this dissertation, …
Comparisons Of Oral, Intestinal, And Pancreatic Bacterial Microbiomes In Patients With Pancreatic Cancer And Other Gastrointestinal Diseases, Mei Chung, Naisi Zhao, Richard Meier, Devin C. Koestler, Guojun Wu, Erika De Castillo, Bruce J. Paster, Kevin Charpentier, Jacques Izard, Karl T. Kelsey, Dominique S. Michaud
Comparisons Of Oral, Intestinal, And Pancreatic Bacterial Microbiomes In Patients With Pancreatic Cancer And Other Gastrointestinal Diseases, Mei Chung, Naisi Zhao, Richard Meier, Devin C. Koestler, Guojun Wu, Erika De Castillo, Bruce J. Paster, Kevin Charpentier, Jacques Izard, Karl T. Kelsey, Dominique S. Michaud
Department of Food Science and Technology: Faculty Publications
Background: Oral microbiota is believed to play important roles in systemic diseases, including cancer. Methods: We collected oral samples (tongue, buccal, supragingival, and saliva) and pancreatic tissue or intestinal samples from 52 subjects, and characterized 16S rRNA genes using high-throughput DNA sequencing.
Results: Bray–Curtis plot showed clear separations between bacterial communities in the oral cavity and those in intestinal and pancreatic tissue samples. PERMANOVA tests indicated that bacterial communities from buccal samples were similar to supragingival and saliva samples, and pancreatic duct samples were similar to pancreatic tumor samples, but all other samples were significantly different from each …
Pandemic Vibrio Cholerae Shuts Down Site-Specific Recombination To Retain An Interbacterial Defence Mechanism, Francis J. Santoriello, Lina Michel, Daniel Unterweger, Stefan Pukatzki
Pandemic Vibrio Cholerae Shuts Down Site-Specific Recombination To Retain An Interbacterial Defence Mechanism, Francis J. Santoriello, Lina Michel, Daniel Unterweger, Stefan Pukatzki
Publications and Research
Vibrio cholerae is an aquatic microbe that can be divided into three subtypes: harmless environmental strains, localised pathogenic strains, and pandemic strains causing global cholera outbreaks. Each type has a contact-dependent type VI secretion system (T6SS) that kills neighbouring competitors by translocating unique toxic effector proteins. Pandemic isolates possess identical effectors, indicating that T6SS effectors may affect pandemicity. Here, we show that one of the T6SS gene clusters (Aux3) exists in two states: a mobile, prophage-like element in a small subset of environmental strains, and a truncated Aux3 unique to and conserved in pandemic isolates. Environmental Aux3 can be readily …
Acute Ischemic Stroke As The Presenting Feature Of Covid-19 In The Young And Pregnant, Nermila A. Ballmick, Jiri F. Kubac, Hossein Akhondi
Acute Ischemic Stroke As The Presenting Feature Of Covid-19 In The Young And Pregnant, Nermila A. Ballmick, Jiri F. Kubac, Hossein Akhondi
HCA Healthcare Journal of Medicine
Introduction: Coronavirus disease (COVID-19) is an emerging and rapidly evolving public health issue that has become globally widespread and an overwhelming pandemic. Clinical manifestations of the disease include asymptomatic carrier states, acute respiratory distress syndrome, and even multiorgan dysfunction. Here, we present a unique and rare case of an acute ischemic stroke (AIS) in an asymptomatic pregnant woman with no predisposing medical illnesses.
Discussion: An 18-year-old G2P1 African American woman at 7 weeks gestational age with no significant medical or family history presenting to the Emergency Department during the initial phases of the pandemic with complaints of new onset left …
Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma
Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Clostridioides difficile is recognized as one of the most important pathogens in hospital and community healthcare settings. The clinical outcome of infection of toxigenic C. difficile infection (CDI) ranges from asymptomatic colonization to fulminant pseudomembranous colitis and death. In recent studies, it has been suggested that a high proportion of nosocomial CDI cases are transmitted from asymptomatic carriers which might be acting as infection reservoirs. Understanding what causes the different responses to infection could lead to the development of novel prevention and treatment strategies. Although several explanations have been proposed to explain variations in susceptibility, understanding of the exact mechanisms …
Chain-Selective Isotopic Labeling Of The Heterodimeric Type Iii Secretion Chaperone, Scc4:Scc1, Reveals The Total Structural Rearrangement Of The Chlamydia Trachomatis Bi-Functional Protein, Scc4, Thilini O. Ukwaththage, Samantha M. Keane, Li Shen, Megan A. Macnaughtan
Chain-Selective Isotopic Labeling Of The Heterodimeric Type Iii Secretion Chaperone, Scc4:Scc1, Reveals The Total Structural Rearrangement Of The Chlamydia Trachomatis Bi-Functional Protein, Scc4, Thilini O. Ukwaththage, Samantha M. Keane, Li Shen, Megan A. Macnaughtan
School of Medicine Faculty Publications
Scc4 is an unusual bi-functional protein from Chlamydia trachomatis (CT) that functions as a type III secretion system (T3SS) chaperone and an RNA polymerase (RNAP)-binding protein. Both functions require interactions with protein partners during specific stages of the CT developmental cycle. As a T3SS chaperone, Scc4 binds Scc1 during the late stage of development to form a heterodimer complex, which chaperones the essential virulence effector, CopN. During the early-middle stage of development, Scc4 regulates T3SS gene expression by binding the σ66-containing RNAP holoenzyme. In order to study the structure and association mechanism of the Scc4:Scc1 T3SS chaperone complex using nuclear …
Évaluation De L'Exposition Des Thanatopracteurs Aux Bioaérosols Et Appréciation Du Risque Sur Leur Santé, Geneviève Marchand, Loïc Wingert, Stéphane Hallé, Maximilien Debia
Évaluation De L'Exposition Des Thanatopracteurs Aux Bioaérosols Et Appréciation Du Risque Sur Leur Santé, Geneviève Marchand, Loïc Wingert, Stéphane Hallé, Maximilien Debia
Rapports de recherche scientifique
Plusieurs manipulations réalisées sur les corps des défunts par les thanatopracteurs produisent des bioaérosols qui peuvent contenir des agents pathogènes infectieux. La ventilation générale est souvent le seul moyen utilisé dans les laboratoires de thanatopraxie pour maîtriser les bioaérosols. Toutefois, il n’y a pas de recommandations précises pour sa mise en application. De plus, peu d'études abordent les expositions professionnelles aux bioaérosols dans le domaine de la thanatopraxie tant quantitativement (niveau d’exposition) que qualitativement (identification et classification selon les groupes de risque). L’objectif de cette étude était d’évaluer l’exposition des thanatopracteurs aux bioaérosols afin d’apprécier les risques potentiels sur leur …
Development, Expansion And Role Of Myeloid-Derived Suppressor Cells In Post-Sepsis Immune Suppression, Tuqa Alkhateeb
Development, Expansion And Role Of Myeloid-Derived Suppressor Cells In Post-Sepsis Immune Suppression, Tuqa Alkhateeb
Electronic Theses and Dissertations
Myeloid-derived suppressor cells (MDSCs) numbers increase significantly in sepsis and are associated with high mortality rates. These myeloid cell precursors promote immunosuppression, especially in the late (post sepsis) stage. However, the mechanisms that underlie MDSC expansion and programming are not completely understood. To investigate these mechanisms, we used a cecal-ligation and puncture (CLP) mouse model of polymicrobial sepsis that progresses from an early/acute proinflammatory phase to a late/chronic immunosuppressive phase. Previous studies in our laboratory showed that microRNA (miR)-21 and miR-181b elevate levels of the transcription factor nuclear factor 1 (NFI-A) that promotes MDSC expansion. We report here that miR-21 …
Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding
Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding
Electronic Theses and Dissertations
Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …
Deacetylation Of Hsd17b10 By Sirt3 Regulates Cell Growth And Cell Resistance Under Oxidative And Starvation Stresses., Lu Liu, Shuaiyi Chen, Miao Yu, Chenxu Ge, Mengmeng Ren, Boya Liu, Xin Yang, Thomas W Christian, Ya-Ming Hou, Junhua Zou, Wei-Guo Zhu, Jianyuan Luo
Deacetylation Of Hsd17b10 By Sirt3 Regulates Cell Growth And Cell Resistance Under Oxidative And Starvation Stresses., Lu Liu, Shuaiyi Chen, Miao Yu, Chenxu Ge, Mengmeng Ren, Boya Liu, Xin Yang, Thomas W Christian, Ya-Ming Hou, Junhua Zou, Wei-Guo Zhu, Jianyuan Luo
Department of Biochemistry and Molecular Biology Faculty Papers
17-beta-hydroxysteroid dehydrogenase 10 (HSD17B10) plays an important role in mitochondrial fatty acid metabolism and is also involved in mitochondrial tRNA maturation. HSD17B10 missense mutations cause HSD10 mitochondrial disease (HSD10MD). HSD17B10 with mutations identified from cases of HSD10MD show loss of function in dehydrogenase activity and mitochondrial tRNA maturation, resulting in mitochondrial dysfunction. It has also been implicated to play roles in the development of Alzheimer disease (AD) and tumorigenesis. Here, we found that HSD17B10 is a new substrate of NAD-dependent deacetylase Sirtuin 3 (SIRT3). HSD17B10 is acetylated at lysine residues K79, K99 and K105 by the acetyltransferase CBP, and the …
Identifying Determinants Of Target Specificity In Two Related Bacterial Peptide Toxins, Andrew D. Holmes
Identifying Determinants Of Target Specificity In Two Related Bacterial Peptide Toxins, Andrew D. Holmes
Honors Thesis
Toxin-antitoxin (TA) systems were originally identified as two-component systems ensuring the stable inheritance of plasmids in bacterial populations. Recently, they have been identified on bacterial chromosomes where their functions remain mostly undefined. The par locus of E. faecalis plasmid pAD1 (parpAD1) was the first TA system defined in a Gram-positive bacterium and a homolog encoded on the E. faecalis chromosome (parEF0409) was later described. Related loci numbering in the hundreds have been identified throughout Gram-positive bacteria based on homology to the toxin of the system, Fst, and similarities in genetic organization and regulation. Despite …
Gut Pathophysiology In Mouse Models Of Social Behavior Deficits, Kyla Scott
Gut Pathophysiology In Mouse Models Of Social Behavior Deficits, Kyla Scott
Undergraduate Honors Theses
Autism spectrum disorders (ASD) encompass neurodevelopment disorders characterized by atypical patterns of development that impact multiple areas of functioning beginning in early childhood. The etiology of ASD is unknown and there are currently no preventative treatment options. Gastrointestinal symptoms are commonly associated comorbidities. The microbiota-gut-brain axis is a multidirectional communication chain that connects the central and enteric nervous system that relates brain function to peripheral intestinal functions. Changes within this axis have been postulated in ASD. For example, the “leaky gut theory” proposes that chronic inflammation is linked to alterations in the bacterial profiles of the gut microbiome and subsequent …
Molecular Mechanisms Of Antimicrobial Resistance In Multi-Drug Resistant Enterococci, Ayesha Khan
Molecular Mechanisms Of Antimicrobial Resistance In Multi-Drug Resistant Enterococci, Ayesha Khan
Dissertations and Theses (Open Access)
Antibiotic resistance is a major global public health threat. Enterococci are recalcitrant, nosocomial pathogens that can be intrinsically resistant to valuable antibiotics, like beta-lactams, or evolve resistance to all existing antimicrobials. The LiaFSR system regulates resistance to cell membrane (CM) stressors like daptomycin (DAP), a front-line drug for multi-drug resistant infections. DAP resistance (DAP-R) in E. faecalis is mediated by CM phospholipid alterations. Emergence of DAP-R often leads to b-lactam resensitization, a phenomenon called the seesaw effect. The molecular mechanism of DAP-R and the seesaw effect are unknown. Here we show that LiaX is a surface exposed protein whose C-terminal …
Transcriptomic Responses To Coaggregation Between Oral Bacteria, V R Mutha Naresh
Transcriptomic Responses To Coaggregation Between Oral Bacteria, V R Mutha Naresh
Student Works (2020-2029)
Cell-cell interactions between genetically distinct oral bacteria form macroscopic clumps known as coaggregates. These interactions, termed coaggregation contribute to the formation of highly structured multispecies communities in oral cavity, known as oral biofilms. Individual species also compete and collaborate with other neighboring species through metabolic interactions allowing growth of other species by coaggregation. This study involves the mixing of selected pairs of oral bacteria to form coaggregates and quantifying differential gene expression levels in each pair in comparison with mono-species coaggregation. The dual RNA-Seq approach made it possible to see how bacteria respond to one another leading to different metabolic …
Biological Sex Influences Susceptibility To Acinetobacter Baumannii Pneumonia In Mice, Sílvia Pires, Adeline Peignier, Jeremy Seto, Davida S. Smyth, Dane Parker
Biological Sex Influences Susceptibility To Acinetobacter Baumannii Pneumonia In Mice, Sílvia Pires, Adeline Peignier, Jeremy Seto, Davida S. Smyth, Dane Parker
Publications and Research
Acinetobacter baumannii (A. baumannii) is an extremely versatile multidrug-resistant pathogen with a very high mortality rate; therefore, it has become crucial to understand the host response during its infection. Given the importance of mice for modeling infection and their role in preclinical drug development, equal emphasis should be placed on the use of both sexes. Through our studies using a murine model of acute pneumonia with A. baumannii, we observed that female mice were more susceptible to infection. Likewise, treatment of male mice with estradiol increased their susceptibility to infection. Analysis of the airway compartment revealed enhanced inflammation and reduced …