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 1329

Publication Record

Connections

Bacterial Energetic Requirements for Helicobacter pylori Cag Type IV Secretion System-Dependent Alterations in Gastric Epithelial Cells.
Lin AS, Dooyema SDR, Frick-Cheng AE, Harvey ML, Suarez G, Loh JT, McDonald WH, McClain MS, Peek RM, Cover TL
(2020) Infect Immun 88:
MeSH Terms: Antigens, Bacterial, Bacterial Proteins, Biological Transport, DNA, Bacterial, Epithelial Cells, Helicobacter pylori, Humans, Interleukin-8, Lipopolysaccharides, NF-kappa B, Peptidoglycan, Toll-Like Receptor 9, Type IV Secretion Systems, Virulence Factors
Show Abstract · Added March 3, 2020
colonizes the stomach in about half of the world's population. strains containing the pathogenicity island ( PAI) are associated with a higher risk of gastric adenocarcinoma or peptic ulcer disease than PAI-negative strains. The PAI encodes a type IV secretion system (T4SS) that mediates delivery of the CagA effector protein as well as nonprotein bacterial constituents into gastric epithelial cells. -induced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and interleukin-8 (IL-8) secretion are attributed to T4SS-dependent delivery of lipopolysaccharide metabolites and peptidoglycan into host cells, and Toll-like receptor 9 (TLR9) activation is attributed to delivery of bacterial DNA. In this study, we analyzed the bacterial energetic requirements associated with these cellular alterations. Mutant strains lacking Cagα, Cagβ, or CagE (putative ATPases corresponding to VirB11, VirD4, and VirB4 in prototypical T4SSs) were capable of T4SS core complex assembly but defective in CagA translocation into host cells. Thus, the three Cag ATPases are not functionally redundant. Cagα and CagE were required for -induced NF-κB activation, IL-8 secretion, and TLR9 activation, but Cagβ was dispensable for these responses. We identified putative ATP-binding motifs (Walker-A and Walker-B) in each of the ATPases and generated mutant strains in which these motifs were altered. Each of the Walker box mutant strains exhibited properties identical to those of the corresponding deletion mutant strains. These data suggest that Cag T4SS-dependent delivery of nonprotein bacterial constituents into host cells occurs through mechanisms different from those used for recruitment and delivery of CagA into host cells.
Copyright © 2020 American Society for Microbiology.
0 Communities
1 Members
0 Resources
MeSH Terms
Histone deacetylase 3 controls a transcriptional network required for B cell maturation.
Stengel KR, Bhaskara S, Wang J, Liu Q, Ellis JD, Sampathi S, Hiebert SW
(2019) Nucleic Acids Res 47: 10612-10627
MeSH Terms: Animals, Antigens, CD19, B-Lymphocytes, Base Sequence, Cell Differentiation, Gene Expression Regulation, Gene Regulatory Networks, Histone Deacetylase Inhibitors, Histone Deacetylases, Lipopolysaccharides, Lymphocyte Activation, Mice, Inbred C57BL, Plasma Cells, Positive Regulatory Domain I-Binding Factor 1, Proto-Oncogene Proteins c-bcl-6, Repressor Proteins, Transcription, Genetic, Up-Regulation
Show Abstract · Added October 25, 2019
Histone deacetylase 3 (Hdac3) is a target of the FDA approved HDAC inhibitors, which are used for the treatment of lymphoid malignancies. Here, we used Cd19-Cre to conditionally delete Hdac3 to define its role in germinal center B cells, which represent the cell of origin for many B cell malignancies. Cd19-Cre-Hdac3-/- mice showed impaired germinal center formation along with a defect in plasmablast production. Analysis of Hdac3-/- germinal centers revealed a reduction in dark zone centroblasts and accumulation of light zone centrocytes. RNA-seq revealed a significant correlation between genes up-regulated upon Hdac3 loss and those up-regulated in Foxo1-deleted germinal center B cells, even though Foxo1 typically activates transcription. Therefore, to determine whether gene expression changes observed in Hdac3-/- germinal centers were a result of direct effects of Hdac3 deacetylase activity, we used an HDAC3 selective inhibitor and examined nascent transcription in germinal center-derived cell lines. Transcriptional changes upon HDAC3 inhibition were enriched for light zone gene signatures as observed in germinal centers. Further comparison of PRO-seq data with ChIP-seq/exo data for BCL6, SMRT, FOXO1 and H3K27ac identified direct targets of HDAC3 function including CD86, CD83 and CXCR5 that are likely responsible for driving the light zone phenotype observed in vivo.
© The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research.
1 Communities
0 Members
0 Resources
18 MeSH Terms
Single-cell transcriptomics reveal polyclonal memory T-cell responses in skin with positive abacavir patch test results.
Redwood AJ, Rwandamuriye F, Chopra A, Leary S, Ram R, McDonnell W, Konvinse K, White K, Pavlos R, Koelle DM, Mallal S, Phillips EJ
(2019) J Allergy Clin Immunol 144: 1413-1416.e7
MeSH Terms: Aged, Anti-HIV Agents, Arthralgia, CD8-Positive T-Lymphocytes, Dideoxynucleosides, Drug Hypersensitivity, Drug-Related Side Effects and Adverse Reactions, Gene Expression Profiling, HLA-B Antigens, Headache, Humans, Immunologic Memory, Lymphocyte Activation, Male, Myalgia, Patch Tests, Single-Cell Analysis, Skin
Added March 30, 2020
0 Communities
1 Members
0 Resources
18 MeSH Terms
Systematic review with meta-analysis: association between Helicobacter pylori CagA seropositivity and odds of inflammatory bowel disease.
Tepler A, Narula N, Peek RM, Patel A, Edelson C, Colombel JF, Shah SC
(2019) Aliment Pharmacol Ther 50: 121-131
MeSH Terms: Adolescent, Adult, Antibodies, Bacterial, Antigens, Bacterial, Bacterial Proteins, Colitis, Ulcerative, Comorbidity, Crohn Disease, Female, Helicobacter Infections, Helicobacter pylori, Humans, Inflammatory Bowel Diseases, Male, Middle Aged, Seroepidemiologic Studies, Young Adult
Show Abstract · Added March 3, 2020
BACKGROUND - Accumulating data support a protective role of Helicobacter pylori against inflammatory bowel diseases (IBD), which might be mediated by strain-specific constituents, specifically cagA expression.
AIM - To perform a systematic review and meta-analysis to more clearly define the association between CagA seropositivity and IBD.
METHODS - We identified comparative studies that included sufficient detail to determine the odds or risk of IBD, Crohn's disease (CD) or ulcerative colitis (UC) amongst individuals with vs without evidence of cagA expression (eg CagA seropositivity). Estimates were pooled using a random effects model.
RESULTS - Three clinical studies met inclusion criteria. cagA expression was represented by CagA seropositivity in all studies. Compared to CagA seronegativity overall, CagA seropositivity was associated with lower odds of IBD (OR 0.31, 95% CI 0.21-0.44) and CD (OR 0.25, 95% CI 0.17-0.38), and statistically nonsignificant lower odds for UC (OR 0.68, 95% CI 0.35-1.32). Similarly, compared to H pylori non-exposed individuals, H pylori exposed, CagA seropositive individuals had lower odds of IBD (OR 0.26, 95% CI 0.16-0.41) and CD (OR 0.23, 95% CI 0.15-0.35), but not UC (OR 0.66, 0.34-1.27). However, there was no significant difference in the odds of IBD, CD or UC between H pylori exposed, CagA seronegative and H pylori non-exposed individuals.
CONCLUSION - We found evidence for a significant association between CagA seropositive H pylori exposure and reduced odds of IBD, particularly CD, but not for CagA seronegative H pylori exposure. Additional studies are needed to confirm these findings and define underlying mechanisms.
© 2019 John Wiley & Sons Ltd.
0 Communities
1 Members
0 Resources
17 MeSH Terms
A Rapid Allele-Specific Assay for HLA-A*32:01 to Identify Patients at Risk for Vancomycin-Induced Drug Reaction with Eosinophilia and Systemic Symptoms.
Rwandamuriye FX, Chopra A, Konvinse KC, Choo L, Trubiano JA, Shaffer CM, Watson M, Mallal SA, Phillips EJ
(2019) J Mol Diagn 21: 782-789
MeSH Terms: Alleles, Anti-Bacterial Agents, Base Sequence, Drug Hypersensitivity Syndrome, Eosinophilia, Genetic Testing, HLA-A Antigens, Humans, Polymerase Chain Reaction, Sequence Homology, Vancomycin
Show Abstract · Added March 30, 2020
Human leukocyte antigen (HLA) alleles have been implicated as risk factors for immune-mediated adverse drug reactions. The authors recently reported a strong association between HLA-A*32:01 and vancomycin-induced drug reaction with eosinophilia and systemic symptoms. Identification of individuals with the risk allele before or shortly after the initiation of vancomycin therapy is of great clinical importance to prevent morbidity and mortality, and improve drug safety and antibiotic treatment options. A prerequisite to the success of pharmacogenetic screening tests is the development of simple, robust, cost-effective single HLA allele test that can be implemented in routine diagnostic laboratories. In this study, the authors developed a simple, real-time allele-specific PCR for typing the HLA-A*32:01 allele. Four-hundred and fifty-eight DNA samples including 30 HLA-A*32:01-positive samples were typed by allele-specific PCR. Compared with American Society for Histocompatibility and Immunogenetics-accredited, sequence-based, high-resolution, full-allelic HLA typing, this assay demonstrates 100% accuracy, 100% sensitivity (95% CI, 88.43% to 100%), and 100% specificity (95% CI, 99.14% to 100%). The lowest limit of detection of this assay using PowerUp SYBR Green is 10 ng of template DNA. The assay demonstrates a sensitivity and specificity to differentiate the HLA-A*32:01 allele from closely related non-HLA-A*32 alleles and may be used in clinical settings to identify individuals with the risk allele before or during the course of vancomycin therapy.
Copyright © 2019 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.
0 Communities
1 Members
0 Resources
11 MeSH Terms
Regulation of Diabetogenic Immunity by IL-15-Activated Regulatory CD8 T Cells in Type 1 Diabetes.
Stocks BT, Wilson CS, Marshall AF, Hoopes EM, Moore DJ
(2019) J Immunol 203: 158-166
MeSH Terms: Adoptive Transfer, Animals, B-Lymphocytes, CD8 Antigens, Cells, Cultured, Diabetes Mellitus, Type 1, Disease Models, Animal, Humans, Immunotherapy, Adoptive, Interleukin-15, Macrophages, Mice, Mice, Inbred NOD, NK Cell Lectin-Like Receptor Subfamily A, T-Lymphocytes, Regulatory
Show Abstract · Added May 28, 2019
Unchecked collaboration between islet-reactive T and B lymphocytes drives type 1 diabetes (T1D). In the healthy setting, CD8 T regulatory cells (Tregs) terminate ongoing T-B interactions. We determined that specific CD8 Tregs from NOD mice lack suppressive function, representing a previously unreported regulatory cell deficit in this T1D-prone strain. NOD mice possess 11-fold fewer Ly-49 CD8 Tregs than nonautoimmune mice, a deficiency that worsens as NOD mice age toward diabetes and leaves them unable to regulate CD4 T follicular helper cells. As IL-15 is required for Ly-49 CD8 Treg development, we determined that NOD macrophages inadequately -present IL-15. Despite reduced IL-15 -presentation, NOD Ly-49 CD8 Tregs can effectively transduce IL-15-mediated survival signals when they are provided. Following stimulation with an IL-15/IL-15Ra superagonist complex, Ly-49 CD8 Tregs expanded robustly and became activated to suppress the Ag-specific Ab response. IL-15/IL-15Ra superagonist complex-activated CD8CD122 T cells also delayed diabetes transfer, indicating the presence of an underactivated CD8 T cell subset with regulatory capacity against late stage T1D. We identify a new cellular contribution to anti-islet autoimmunity and demonstrate the correction of this regulatory cell deficit. Infusion of IL-15-activated CD8 Tregs may serve as an innovative cellular therapy for the treatment of T1D.
Copyright © 2019 by The American Association of Immunologists, Inc.
0 Communities
1 Members
0 Resources
15 MeSH Terms
Molecular Architecture of the Helicobacter pylori Cag Type IV Secretion System.
Hu B, Khara P, Song L, Lin AS, Frick-Cheng AE, Harvey ML, Cover TL, Christie PJ
(2019) mBio 10:
MeSH Terms: Antigens, Bacterial, Bacterial Proteins, Cryoelectron Microscopy, Genomic Islands, Helicobacter pylori, Humans, Type IV Secretion Systems
Show Abstract · Added July 14, 2019
colonizes about half of humans worldwide, and its presence in the gastric mucosa is associated with an increased risk of gastric adenocarcinoma, gastric lymphoma, and peptic ulcer disease. strains carrying the pathogenicity island (PAI) are associated with increased risk of disease progression. The PAI encodes the Cag type IV secretion system (Cag), which delivers the CagA oncoprotein and other effector molecules into human gastric epithelial cells. We visualized structures of native and mutant Cag machines on the cell envelope by cryoelectron tomography. Individual cells contain multiple Cag nanomachines, each composed of a wheel-shaped outer membrane complex (OMC) with 14-fold symmetry and an inner membrane complex (IMC) with 6-fold symmetry. CagX, CagY, and CagM are required for assembly of the OMC, whereas strains lacking Cag3 and CagT produce outer membrane complexes lacking peripheral components. The IMC, which has never been visualized in detail, is configured as six tiers in cross-section view and three concentric rings surrounding a central channel in end-on view. The IMC contains three T4SS ATPases: (i) VirB4-like CagE, arranged as a hexamer of dimers at the channel entrance; (ii) a hexamer of VirB11-like Cagα, docked at the base of the CagE hexamer; and (iii) VirD4-like Cagβ and other unspecified Cag subunits, associated with the stacked CagE/Cagα complex and forming the outermost rings. The Cag and recently solved Dot/Icm system comprise new structural prototypes for the T4SS superfamily. Bacterial type IV secretion systems (T4SSs) have been phylogenetically grouped into two subfamilies. The T4ASSs, represented by the VirB/VirD4, include "minimized" machines assembled from 12 VirB- and VirD4-like subunits and compositionally larger systems such as the Cag T4BSSs encompass systems closely related in subunit composition to the Dot/Icm Here, we present structures of native and mutant Cag machines determined by cryoelectron tomography. We identify distinct outer and inner membrane complexes and, for the first time, visualize structural contributions of all three "signature" ATPases of T4SSs at the cytoplasmic entrance of the translocation channel. Despite their evolutionary divergence, the Cag aligns structurally much more closely to the Dot/Icm than an available VirB/VirD4 subcomplex. Our findings highlight the diversity of T4SSs and suggest a structural classification scheme in which T4SSs are grouped as minimized VirB/VirD4-like or larger Cag-like and Dot/Icm-like systems.
Copyright © 2019 Hu et al.
0 Communities
1 Members
0 Resources
MeSH Terms
Shared Genetic Risk Factors Across Carbamazepine-Induced Hypersensitivity Reactions.
Nicoletti P, Barrett S, McEvoy L, Daly AK, Aithal G, Lucena MI, Andrade RJ, Wadelius M, Hallberg P, Stephens C, Bjornsson ES, Friedmann P, Kainu K, Laitinen T, Marson A, Molokhia M, Phillips E, Pichler W, Romano A, Shear N, Sills G, Tanno LK, Swale A, Floratos A, Shen Y, Nelson MR, Watkins PB, Daly MJ, Morris AP, Alfirevic A, Pirmohamed M
(2019) Clin Pharmacol Ther 106: 1028-1036
MeSH Terms: Adult, Anaplastic Lymphoma Kinase, Carbamazepine, Chemical and Drug Induced Liver Injury, Drug Hypersensitivity, Drug Hypersensitivity Syndrome, Europe, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, HLA-A Antigens, HLA-B Antigens, Humans, Male, Phenotype, Risk Factors, Stevens-Johnson Syndrome
Show Abstract · Added March 30, 2020
Carbamazepine (CBZ) causes life-threating T-cell-mediated hypersensitivity reactions, including serious cutaneous adverse reactions (SCARs) and drug-induced liver injury (CBZ-DILI). In order to evaluate shared or phenotype-specific genetic predisposing factors for CBZ hypersensitivity reactions, we performed a meta-analysis of two genomewide association studies (GWAS) on a total of 43 well-phenotyped Northern and Southern European CBZ-SCAR cases and 10,701 population controls and a GWAS on 12 CBZ-DILI cases and 8,438 ethnically matched population controls. HLA-A*31:01 was identified as the strongest genetic predisposing factor for both CBZ-SCAR (odds ratio (OR) = 8.0; 95% CI 4.10-15.80; P = 1.2 × 10 ) and CBZ-DILI (OR = 7.3; 95% CI 2.47-23.67; P = 0.0004) in European populations. The association with HLA-A*31:01 in patients with SCAR was mainly driven by hypersensitivity syndrome (OR = 12.9; P = 2.1 × 10 ) rather than by Stevens-Johnson syndrome/toxic epidermal necrolysis cases, which showed an association with HLA-B*57:01. We also identified a novel risk locus mapping to ALK only for CBZ-SCAR cases, which needs replication in additional cohorts and functional evaluation.
© 2019 The Authors Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.
0 Communities
1 Members
0 Resources
17 MeSH Terms
FcγRIIb on CD11c cells modulates serum cholesterol and triglyceride levels and differentially affects atherosclerosis in male and female Ldlr mice.
Marvin J, Rhoads JP, Major AS
(2019) Atherosclerosis 285: 108-119
MeSH Terms: Animals, Atherosclerosis, CD11 Antigens, Cholesterol, Dendritic Cells, Female, Male, Mice, Mice, Inbred C57BL, Receptors, IgG, Sex Factors, Triglycerides
Show Abstract · Added March 30, 2020
BACKGROUND AND AIMS - Circulating levels of oxidized lipoprotein (oxLDL) correlate with myocardial infarction risk and atherosclerosis severity. Our previous study demonstrates that oxLDL immune complexes (oxLDL-ICs) can signal through FcγRs on bone marrow-derived dendritic cells (BMDCs) and enhance their activation and inflammatory cytokine secretion. While global FcγR studies have shown that activating FcγRs are proatherogenic, the role of the inhibitory FcγRIIb is unclear. We sought to determine the role of DC-specific FcγRIIb in atherosclerosis.
METHODS - Bone marrow chimeras were generated by rescuing lethally irradiated Ldlr mice with hematopoietic cells from littermate CD11c-Cre or CD11c-CreFcgr2b donors. Four weeks following transplant, recipients were placed on a Western diet for eight weeks. Various tissues and organs were analyzed for differences in inflammation.
RESULTS - Quantitation of atherosclerosis in the proximal aorta demonstrated a 58% increase in female CD11c-CreFcgr2b recipients, but a surprising 44% decrease in male recipients. Hepatic cholesterol and triglycerides were increased in female CD11c-CreFcgr2b recipients. This was associated with an increase in CD36 and MHC Class II expression on hepatic CD11cCD11b DCs in female livers. In contrast, male CD11c-CreFcgr2b recipients had decreased hepatic lipids with a corresponding decrease in CD36 and MHC Class II expression on CD11c cells. Interestingly, both sexes of CD11c-CreFcgr2b recipients had significant decreases in serum cholesterol and TGs with corresponding decreases in liver Fasn transcripts.
CONCLUSIONS - The absence of FcγRIIb expression on CD11c cells results in sex-dependent alteration in liver inflammation influencing atherogenesis and sex-independent modulation of serum cholesterol and TGs.
Published by Elsevier B.V.
0 Communities
1 Members
0 Resources
12 MeSH Terms
HLA-A*32:01 is strongly associated with vancomycin-induced drug reaction with eosinophilia and systemic symptoms.
Konvinse KC, Trubiano JA, Pavlos R, James I, Shaffer CM, Bejan CA, Schutte RJ, Ostrov DA, Pilkinton MA, Rosenbach M, Zwerner JP, Williams KB, Bourke J, Martinez P, Rwandamuriye F, Chopra A, Watson M, Redwood AJ, White KD, Mallal SA, Phillips EJ
(2019) J Allergy Clin Immunol 144: 183-192
MeSH Terms: Adolescent, Adult, Aged, Anti-Bacterial Agents, Drug Hypersensitivity Syndrome, Female, HLA-A Antigens, Humans, Male, Middle Aged, Molecular Docking Simulation, Vancomycin, Young Adult
Show Abstract · Added March 30, 2020
BACKGROUND - Vancomycin is a prevalent cause of the severe hypersensitivity syndrome drug reaction with eosinophilia and systemic symptoms (DRESS), which leads to significant morbidity and mortality and commonly occurs in the setting of combination antibiotic therapy, affecting future treatment choices. Variations in HLA class I in particular have been associated with serious T cell-mediated adverse drug reactions, which has led to preventive screening strategies for some drugs.
OBJECTIVE - We sought to determine whether variation in the HLA region is associated with vancomycin-induced DRESS.
METHODS - Probable vancomycin-induced DRESS cases were matched 1:2 with tolerant control subjects based on sex, race, and age by using BioVU, Vanderbilt's deidentified electronic health record database. Associations between DRESS and carriage of HLA class I and II alleles were assessed by means of conditional logistic regression. An extended sample set from BioVU was used to conduct a time-to-event analysis of those exposed to vancomycin with and without the identified HLA risk allele.
RESULTS - Twenty-three subjects met the inclusion criteria for vancomycin-associated DRESS. Nineteen (82.6%) of 23 cases carried HLA-A*32:01 compared with 0 (0%) of 46 of the matched vancomycin-tolerant control subjects (P = 1 × 10) and 6.3% of the BioVU population (n = 54,249, P = 2 × 10). Time-to-event analysis of DRESS development during vancomycin treatment among the HLA-A*32:01-positive group indicated that 19.2% had DRESS and did so within 4 weeks.
CONCLUSIONS - HLA-A*32:01 is strongly associated with vancomycin-induced DRESS in a population of predominantly European ancestry. HLA-A*32:01 testing could improve antibiotic safety, help implicate vancomycin as the causal drug, and preserve future treatment options with coadministered antibiotics.
Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
0 Communities
1 Members
0 Resources
13 MeSH Terms