Other search tools

About this data

The publication data currently available has been vetted by Vanderbilt faculty, staff, administrators and trainees. The data itself is retrieved directly from NCBI's PubMed and is automatically updated on a weekly basis to ensure accuracy and completeness.

If you have any questions or comments, please contact us.

Results: 1 to 10 of 1427

Publication Record

Connections

VacA Targets Myeloid Cells in the Gastric Lamina Propria To Promote Peripherally Induced Regulatory T-Cell Differentiation and Persistent Infection.
Altobelli A, Bauer M, Velez K, Cover TL, Müller A
(2019) MBio 10:
MeSH Terms: Animals, Bacterial Proteins, Cell Differentiation, Dendritic Cells, Disease Models, Animal, Gastric Mucosa, Helicobacter Infections, Helicobacter pylori, Immune Evasion, Interleukin-10, Interleukin-23, Lung, Macrophages, Mice, Mucous Membrane, Myeloid Cells, T-Lymphocytes, Regulatory, Transforming Growth Factor beta
Show Abstract · Added April 11, 2019
The gastric bacterium causes a persistent infection that is directly responsible for gastric ulcers and gastric cancer in some patients and protective against allergic and other immunological disorders in others. The two outcomes of the -host interaction can be modeled in mice that are infected as immunocompetent adults and as neonates, respectively. Here, we have investigated the contribution of the immunomodulator VacA to -specific local and systemic immune responses in both models. We found that neonatally infected mice are colonized at higher levels than mice infected as adults and fail to generate effector T-cell responses to the bacteria; rather, T-cell responses in neonatally infected mice are skewed toward Foxp3-positive (Foxp3) regulatory T cells that are neuropilin negative and express RORγt. We found these peripherally induced regulatory T cells (pTregs) to be enriched, in a VacA-dependent manner, not only in the gastric mucosa but also in the lungs of infected mice. Pulmonary pTreg accumulation was observed in mice that have been infected neonatally with wild-type but not in mice that have been infected as adults or mice infected with a VacA null mutant. Finally, we traced VacA to gastric lamina propria myeloid cells and show that it suppressed interleukin-23 (IL-23) expression by dendritic cells and induced IL-10 and TGF-β expression in macrophages. Taken together, the results are consistent with the idea that creates a tolerogenic environment through its immunomodulator VacA, which skews T-cell responses toward Tregs, favors persistence, and affects immunity at distant sites. has coexisted with humans for at least 60.000 years and has evolved persistence strategies that allow it to evade host immunity and colonize its host for life. The VacA protein is expressed by all strains and is required for high-level persistent infection in experimental mouse models. Here, we show that VacA targets myeloid cells in the gastric mucosa to create a tolerogenic environment that facilitates regulatory T-cell differentiation, while suppressing effector T-cell priming and functionality. Tregs that are induced in the periphery during infection can be found not only in the stomach but also in the lungs of infected mice, where they are likely to affect immune responses to allergens.
Copyright © 2019 Altobelli et al.
0 Communities
1 Members
0 Resources
18 MeSH Terms
Rabbit Model of Intra-Arterial Chemotherapy Toxicity Demonstrates Retinopathy and Vasculopathy Related to Drug and Dose, Not Procedure or Approach.
Daniels AB, Froehler MT, Nunnally AH, Pierce JM, Bozic I, Stone CA, Santapuram PR, Tao YK, Boyd KL, Himmel LE, Chen SC, Du L, Friedman DL, Richmond A
(2019) Invest Ophthalmol Vis Sci 60: 954-964
MeSH Terms: Animals, Antineoplastic Agents, Antineoplastic Agents, Alkylating, Carboplatin, Dose-Response Relationship, Drug, Electroretinography, Female, Fluorescein Angiography, Humans, Infant, Infusions, Intra-Arterial, Male, Melphalan, Models, Animal, Ophthalmic Artery, Rabbits, Retina, Retinal Diseases, Retinal Neoplasms, Retinal Vessels, Retinoblastoma, Retrospective Studies, Tomography, Optical Coherence
Show Abstract · Added July 29, 2019
Purpose - To use our intra-arterial chemotherapy (IAC) rabbit model to assess the impact of IAC procedure, drug, dose, and choice of technique on ocular structure and function, to study the nature and etiology of IAC toxicity, and to compare to observations in patients.
Methods - Rabbits received IAC melphalan (0.4-0.8 mg/kg), carboplatin (25-50 mg), or saline, either by direct ophthalmic artery cannulation, or with a technique emulating nonocclusion. Ocular structure/function were assessed with examination, electroretinography (ERG), fundus photography, fluorescein angiography, optical coherence tomography (OCT), and OCT angiography, prior to and 5 to 6 weeks after IAC. Blood counts were obtained weekly. We reviewed our last 50 IAC treatments in patients for evidence of ocular or systemic complications.
Results - No toxicity was seen in the saline control group. With standard (0.4 mg/kg) melphalan, no vascular/microvascular abnormalities were seen with either technique. However, severe microvascular pruning and arteriolar occlusions were seen occasionally at 0.8 mg/kg doses. ERG reductions were dose-dependent. Histology showed melphalan dose-dependent degeneration in all retinal layers, restricted geographically to areas of greatest vascular density. Carboplatin caused massive edema of ocular/periocular structures. IAC patients experienced occasional periocular swelling/rash, and only rarely experienced retinopathy or vascular events/hemorrhage in eyes treated multiple times with triple (melphalan/carboplatin/topotecan) therapy. Transient neutropenia occurred after 46% of IAC procedures, generally after triple therapy.
Conclusions - IAC toxicity appears to be related to the specific drug being used and is dose-dependent, rather than related to the IAC procedure itself or the specific technique selected. These rabbit findings are corroborated by our clinical findings in patients.
0 Communities
1 Members
0 Resources
23 MeSH Terms
Manganese Detoxification by MntE Is Critical for Resistance to Oxidative Stress and Virulence of .
Grunenwald CM, Choby JE, Juttukonda LJ, Beavers WN, Weiss A, Torres VJ, Skaar EP
(2019) MBio 10:
MeSH Terms: Animals, Cation Transport Proteins, Disease Models, Animal, Gene Expression Regulation, Bacterial, Homeostasis, Iron, Manganese, Mice, Inbred BALB C, Microbial Viability, Oxidative Stress, Staphylococcal Infections, Staphylococcus aureus, Transcription Factors, Transcription, Genetic, Virulence
Show Abstract · Added April 2, 2019
Manganese (Mn) is an essential micronutrient critical for the pathogenesis of , a significant cause of human morbidity and mortality. Paradoxically, excess Mn is toxic; therefore, maintenance of intracellular Mn homeostasis is required for survival. Here we describe a Mn exporter in , MntE, which is a member of the cation diffusion facilitator (CDF) protein family and conserved among Gram-positive pathogens. Upregulation of transcription in response to excess Mn is dependent on the presence of MntR, a transcriptional repressor of the Mn uptake system. Inactivation of or leads to reduced growth in media supplemented with Mn, demonstrating MntE is required for detoxification of excess Mn. Inactivation of results in elevated levels of intracellular Mn, but reduced intracellular iron (Fe) levels, supporting the hypothesis that MntE functions as a Mn efflux pump and Mn efflux influences Fe homeostasis. Strains inactivated for are more sensitive to the oxidants NaOCl and paraquat, indicating Mn homeostasis is critical for resisting oxidative stress. Furthermore, and are required for full virulence of during infection, suggesting experiences Mn toxicity Combined, these data support a model in which MntR controls Mn homeostasis by balancing transcriptional repression of and induction of , both of which are critical for pathogenesis. Thus, Mn efflux contributes to bacterial survival and virulence during infection, establishing MntE as a potential antimicrobial target and expanding our understanding of Mn homeostasis. Manganese (Mn) is generally viewed as a critical nutrient that is beneficial to pathogenic bacteria due to its function as an enzymatic cofactor and its capability of acting as an antioxidant; yet paradoxically, high concentrations of this transition metal can be toxic. In this work, we demonstrate utilizes the cation diffusion facilitator (CDF) family protein MntE to alleviate Mn toxicity through efflux of excess Mn. Inactivation of leads to a significant reduction in resistance to oxidative stress and mediated mortality within a mouse model of systemic infection. These results highlight the importance of MntE-mediated Mn detoxification in intracellular Mn homeostasis, resistance to oxidative stress, and virulence. Therefore, this establishes MntE as a potential target for development of anti- therapeutics.
Copyright © 2019 Grunenwald et al.
0 Communities
1 Members
0 Resources
15 MeSH Terms
Assessing Acinetobacter baumannii Virulence and Persistence in a Murine Model of Lung Infection.
Palmer LD, Green ER, Sheldon JR, Skaar EP
(2019) Methods Mol Biol 1946: 289-305
MeSH Terms: Acinetobacter Infections, Acinetobacter baumannii, Acute Disease, Animals, Bacterial Load, Biopsy, Disease Models, Animal, Flow Cytometry, Immunity, Immunohistochemistry, Mice, Pneumonia, Bacterial, Virulence
Show Abstract · Added April 2, 2019
Acinetobacter baumannii is a Gram-negative opportunistic pathogen and a leading cause of ventilator-associated pneumonia. Murine models of A. baumannii lung infection allow researchers to experimentally assess A. baumannii virulence and host response. Intranasal administration of A. baumannii models acute lung infection. This chapter describes the methods to test A. baumannii virulence in a murine model of lung infection, including assessing the competitive index of a bacterial mutant and the associated inflammatory responses.
0 Communities
1 Members
0 Resources
13 MeSH Terms
A Phenome-Wide Association Study Uncovers a Pathological Role of Coagulation Factor X during Infection.
Choby JE, Monteith AJ, Himmel LE, Margaritis P, Shirey-Rice JK, Pruijssers A, Jerome RN, Pulley J, Skaar EP
(2019) Infect Immun 87:
MeSH Terms: Acinetobacter Infections, Acinetobacter baumannii, Animals, Disease Models, Animal, Factor X, Host-Pathogen Interactions, Humans, Mice, Mice, Inbred C57BL, Phenotype, Polymorphism, Genetic
Show Abstract · Added April 7, 2019
Coagulation and inflammation are interconnected, suggesting that coagulation plays a key role in the inflammatory response to pathogens. A phenome-wide association study (PheWAS) was used to identify clinical phenotypes of patients with a polymorphism in coagulation factor X. Patients with this single nucleotide polymorphism (SNP) were more likely to be hospitalized with hemostatic and infection-related disorders, suggesting that factor X contributes to the immune response to infection. To investigate this, we modeled infections by human pathogens in a mouse model of factor X deficiency. Factor X-deficient mice were protected from systemic infection, suggesting that factor X plays a role in the immune response to Factor X deficiency was associated with reduced cytokine and chemokine production and alterations in immune cell population during infection: factor X-deficient mice demonstrated increased abundance of neutrophils, macrophages, and effector T cells. Together, these results suggest that factor X activity is associated with an inefficient immune response and contributes to the pathology of infection.
Copyright © 2019 American Society for Microbiology.
0 Communities
1 Members
0 Resources
11 MeSH Terms
iNKT Cell Activation Exacerbates the Development of Huntington's Disease in R6/2 Transgenic Mice.
Park HJ, Lee SW, Im W, Kim M, Van Kaer L, Hong S
(2019) Mediators Inflamm 2019: 3540974
MeSH Terms: Animals, Brain, Cytokines, Disease Models, Animal, Disease Progression, Galactosylceramides, Genotype, Huntington Disease, Leukocytes, Lymphocyte Activation, Mice, Mice, Knockout, Natural Killer T-Cells
Show Abstract · Added March 26, 2019
Huntington's disease (HD) is an inherited neurodegenerative disorder which is caused by a mutation of the huntingtin (HTT) gene. Although the pathogenesis of HD has been associated with inflammatory responses, if and how the immune system contributes to the onset of HD is largely unknown. Invariant natural killer T (iNKT) cells are a group of innate-like regulatory T lymphocytes that can rapidly produce various cytokines such as IFN and IL4 upon stimulation with the glycolipid -galactosylceramide (-GalCer). By employing both R6/2 Tg mice (murine HD model) and J18 KO mice (deficient in iNKT cells), we investigated whether alterations of iNKT cells affect the development of HD in R6/2 Tg mice. We found that J18 KO R6/2 Tg mice showed disease progression comparable to R6/2 Tg mice, indicating that the absence of iNKT cells did not have any significant effects on HD development. However, repeated activation of iNKT cells with -GalCer facilitated HD progression in R6/2 Tg mice, and this was associated with increased infiltration of iNKT cells in the brain. Taken together, our results demonstrate that repeated -GalCer treatment of R6/2 Tg mice accelerates HD progression, suggesting that immune activation can affect the severity of HD pathogenesis.
0 Communities
1 Members
0 Resources
13 MeSH Terms
Structural basis of a potent human monoclonal antibody against Zika virus targeting a quaternary epitope.
Long F, Doyle M, Fernandez E, Miller AS, Klose T, Sevvana M, Bryan A, Davidson E, Doranz BJ, Kuhn RJ, Diamond MS, Crowe JE, Rossmann MG
(2019) Proc Natl Acad Sci U S A 116: 1591-1596
MeSH Terms: Animals, Antibodies, Monoclonal, Antibodies, Neutralizing, Antibodies, Viral, Cryoelectron Microscopy, Disease Models, Animal, Epitopes, Humans, Male, Mice, Mice, Inbred C57BL, Vaccination, Viral Envelope Proteins, Zika Virus, Zika Virus Infection
Show Abstract · Added March 31, 2019
Zika virus (ZIKV) is a major human pathogen and member of the genus in the Flaviviridae family. In contrast to most other insect-transmitted flaviviruses, ZIKV also can be transmitted sexually and from mother to fetus in humans. During recent outbreaks, ZIKV infections have been linked to microcephaly, congenital disease, and Guillain-Barré syndrome. Neutralizing antibodies have potential as therapeutic agents. We report here a 4-Å-resolution cryo-electron microscopy structure of the ZIKV virion in complex with Fab fragments of the potently neutralizing human monoclonal antibody ZIKV-195. The footprint of the ZIKV-195 Fab fragment expands across two adjacent envelope (E) protein protomers. ZIKV neutralization by this antibody is presumably accomplished by cross-linking the E proteins, which likely prevents formation of E protein trimers required for fusion of the viral and cellular membranes. A single dose of ZIKV-195 administered 5 days after virus inoculation showed marked protection against lethality in a stringent mouse model of infection.
0 Communities
1 Members
0 Resources
MeSH Terms
Current Understanding of Humoral Immunity to Enterovirus D68.
Vogt MR, Crowe JE
(2018) J Pediatric Infect Dis Soc 7: S49-S53
MeSH Terms: Animals, Antibodies, Neutralizing, Disease Models, Animal, Enterovirus D, Human, Enterovirus Infections, Epitopes, Humans, Immunity, Humoral, Nervous System Diseases, Respiratory Tract Infections, Seroepidemiologic Studies, Vaccination, Viral Vaccines
Show Abstract · Added March 31, 2019
Enterovirus D68 (EV-D68) is a pathogen that causes outbreaks of respiratory illness across the world, mostly in children, and can be especially severe in those with asthma. Clusters of acute flaccid myelitis, a poliomyelitis-like neuromuscular weakness syndrome, often occur concurrent with EV-D68 respiratory outbreaks. Seroepidemiologic studies have found that the serum of nearly everyone older than 2 to 5 years contains anti-EV-D68 neutralizing antibodies, which suggests that EV-D68 is a ubiquitous pathogen of childhood. However, knowledge of the viral epitopes against which the humoral immune response is directed is only inferred from previous studies of related viruses. Although neutralizing antibodies protect newborn mice from lethal EV-D68 inoculation via nonphysiologic routes, cotton rats have a mixed phenotype of both benefit and possible exacerbation when inoculated intranasally. The human antibody response to EV-D68 needs to be studied further to clarify the role of antibodies in protection versus pathogenesis, which might differ among respiratory and neurologic disease phenotypes.
0 Communities
1 Members
0 Resources
MeSH Terms
MEK Inhibitor Reverses Metaplasia and Allows Re-Emergence of Normal Lineages in Helicobacter pylori-Infected Gerbils.
Yang Q, Yasuda T, Choi E, Toyoda T, Roland JT, Uchida E, Yoshida H, Seto Y, Goldenring JR, Nomura S
(2019) Gastroenterology 156: 577-581.e4
MeSH Terms: Acrylonitrile, Aniline Compounds, Animals, Benzimidazoles, Biopsy, Needle, Disease Models, Animal, Gastric Mucosa, Gerbillinae, Helicobacter Infections, Helicobacter pylori, Immunohistochemistry, Male, Metaplasia, Random Allocation, Reference Values, Treatment Outcome
Added November 14, 2018
0 Communities
1 Members
0 Resources
16 MeSH Terms
Targeted Imaging of VCAM-1 mRNA in a Mouse Model of Laser-Induced Choroidal Neovascularization Using Antisense Hairpin-DNA-Functionalized Gold-Nanoparticles.
Uddin MI, Kilburn TC, Yang R, McCollum GW, Wright DW, Penn JS
(2018) Mol Pharm 15: 5514-5520
MeSH Terms: Animals, Biomarkers, Choroid, Choroidal Neovascularization, Disease Models, Animal, Fluorescent Dyes, Gold, Humans, Intravital Microscopy, Lasers, Male, Metal Nanoparticles, Mice, Mice, Inbred C57BL, Molecular Imaging, Molecular Probes, Oligodeoxyribonucleotides, Antisense, Optical Imaging, RNA, Messenger, Vascular Cell Adhesion Molecule-1, Wet Macular Degeneration
Show Abstract · Added April 10, 2019
Mouse laser-induced choroidal neovascularization (mouse LCNV) recapitulates the "wet" form of human age-related macular degeneration (AMD). Vascular cell adhesion molecule-1 (VCAM-1) is a known inflammatory biomarker, and it increases in the choroidal neovascular tissues characteristic of this experimental model. We have designed and constructed gold nanoparticles (AuNPs) functionalized with hairpin-DNA that incorporates an antisense sequence complementary to VCAM-1 mRNA (AS-VCAM-1 hAuNPs) and tested them as optical imaging probes. The 3' end of the hairpin is coupled to a near-infrared fluorophore that is quenched by the AuNP surface via Förster resonance energy transfer (FRET). Hybridization of the antisense sequence to VCAM-1 mRNA displaces the fluorophore away from the AuNP surface, inducing fluorescent activity. In vitro testing showed that hAuNPs hybridize to an exogenous complementary oligonucleotide within a pH range of 4.5-7.4, and that they are stable at reduced pH. LCNV mice received tail-vein injections of AS-VCAM-1 hAuNPs. Hyperspectral imaging revealed the delivery of AS-VCAM-1 hAuNPs to excised choroidal tissues. Fluorescent images of CNV lesions were obtained, presumably in response to the hybridization of AS-hAuNPs to LCNV-induced VCAM-1 mRNA. This is the first demonstration of systemic delivery of hAuNPs to ocular tissues to facilitate mRNA imaging of any target.
0 Communities
1 Members
0 Resources
21 MeSH Terms