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1.
Immunotherapy ; 14(16): 1315-1328, 2022 11.
Article in English | MEDLINE | ID: mdl-36128795

ABSTRACT

Aim: A novel, Investigational Wearable Infusor (IWI) was evaluated in a randomized, controlled, crossover, open-label study to determine if its delivery of subcutaneous immunoglobulin (IgPro20) achieved a comparable area under the concentration-time curve (AUC) for immunoglobulin G (IgG) versus the Crono S-PID-50 infusion pump (CP). EudraCT: 2016-003798-16. Materials & methods: Patients with primary immunodeficiency (PID) were randomized to receive IgPro20 in Sequence 1 (CP/IWI) or 2 (IWI/CP). The primary end point was AUC for IgG during the final week of each 4-week period. Results: 23 patients were enrolled. Evaluation of area under the concentration-time curve from time 0 (pre-infusion) to 7 days after infusion (AUC0-7 days) (IWI: 1806 h*g/l; CP: 1829 h*g/l) and geometric mean ratio indicated comparable AUCs for IgG for both devices. Conclusion: Similar IgG exposure, indicated by AUC values, can be achieved with IgPro20 using the IWI or CP in PID.


Patients with primary immunodeficiency (PID) are at a higher risk of developing serious infections than healthy individuals. Immunoglobulin G (IgG) replacement therapy reduces this risk, as it raises a patient's antibody levels to help fight off infections. IgG replacement therapy can be performed as an intravenous or subcutaneous (under the skin) infusion. The subcutaneous route is associated with improved quality of life for patients, as therapy can be carried out at home by the patient, allowing for more flexibility, convenience and autonomy. Wearable drug-delivery systems are devices that stick to the body and automatically deliver doses of a drug to the patient. In this study, we investigated whether a novel Investigational Wearable Infusor device could deliver the subcutaneous IgG replacement therapy, IgPro20, in patients with PID. We show that the new infusion device can deliver IgG replacement therapy and allows for similar levels of IgG to be achieved in patients as a comparator device. This wearable drug delivery device simplifies drug administration and could help address some of the challenges associated with self-injection such as complicated infusion preparation, needle phobia and concerns about pain. Trial Registration Number: 2016-003798-16 (EudraCT).


Subject(s)
Immunologic Deficiency Syndromes , Wearable Electronic Devices , Humans , Immunoglobulins, Intravenous , Cross-Over Studies , Immunoglobulin G , Infusion Pumps , Immunologic Deficiency Syndromes/therapy
2.
Am J Infect Control ; 46(12): 1381-1386, 2018 12.
Article in English | MEDLINE | ID: mdl-30509358

ABSTRACT

BACKGROUND: Health care-associated infections (HAIs) are avoidable through good hand hygiene (HH) practices. Hand hygiene compliance systems (HHCSs) have been shown to reliably measure HH adherence, but data on their effectiveness at reducing HAI rates are limited. METHODS: This nonrandomized, pre-post intervention study was conducted at a community hospital in the United States. HAI rates were examined before and after implementation of a HHCS. Preintervention began in January 2014 and intervention began in March 2015; data were collected through September 2017. Additional infection-specific interventions were carried out. HAIs were calculated as incidence rate ratios. RESULTS: The preintervention and intervention periods included 14,297 and 36,890 patients, respectively. The HHCS recorded an average of 696,928 HH opportunities/month. A significant reduction in the rate of catheter-associated urinary tract infections was observed during the intervention: IRR, 0.55; 95% CI, 0.35-0.87. Similarly, a significant reduction in the rate of central line-associated bloodstream infections was observed: IRR, 0.45; 95% CI, 0.23-0.89. DISCUSSION AND CONCLUSIONS: These findings suggest that monitoring HH practices with an automated system, in addition to other infection control measures, may be an effective means of reducing HAIs. Further studies are needed to isolate the potential role of HHCSs in the reduction of HAIs.


Subject(s)
Cross Infection/prevention & control , Guideline Adherence , Hand Hygiene/standards , Health Personnel , Infection Control/methods , Adolescent , Adult , Aged , Aged, 80 and over , Bacteremia/prevention & control , Catheter-Related Infections/prevention & control , Catheterization, Central Venous/adverse effects , Child , Child, Preschool , Female , Hospitals, Community , Humans , Infant , Male , Middle Aged , United States , Urinary Tract Infections/prevention & control , Young Adult
3.
Clin Breast Cancer ; 18(1): e55-e64, 2018 02.
Article in English | MEDLINE | ID: mdl-28733130

ABSTRACT

BACKGROUND: The diagnosis of breast cancer in young women (aged 18-45 years) has been increasing. Women are commonly left coping with treatment-related disabilities of the upper limb that can persist for > 2 years postoperatively. PATIENTS AND METHODS: A total of 59 young breast cancer patients (29 in the intervention group and 30 in the control group) participated in a pilot prospective randomized controlled trial to determine whether a 12-week postradiation exercise program would improve long-term arm mobility, pain, and handgrip strength. During an 18-month period, range of motion, handgrip strength, and pain with shoulder movements were evaluated at 6 points. RESULTS: Although the differences were not statistically significant, external rotation and horizontal abduction of the shoulder improved in the intervention group immediately after the exercise intervention (3 months) and showed a trend toward less pain on movement. However, at 18 months after radiation the control and intervention groups both retained a residual loss of range and persistent pain with movement. Radiation to the axilla and/or chest wall yielded long-term (18 months) limitations in flexion and horizontal abduction compared with hypofractionation, which resulted in greater flexion and external rotation at 18 months. The median grip strength of the study participants corresponded to the 10th percentile of healthy aged-matched white women. CONCLUSION: The exercise intervention timed shortly after radiation improved short-term shoulder mobility and pain; however, these gains were not sustained at 18 months after radiation.


Subject(s)
Breast Neoplasms/therapy , Exercise Therapy/methods , Hand Strength/physiology , Range of Motion, Articular , Shoulder Joint/physiology , Shoulder Pain/rehabilitation , Adult , Axilla , Breast/surgery , Female , Humans , Mastectomy/adverse effects , Pilot Projects , Prospective Studies , Radiotherapy, Adjuvant/adverse effects , Radiotherapy, Adjuvant/methods , Shoulder Pain/etiology , Treatment Outcome , Young Adult
4.
J Cancer Surviv ; 11(6): 791-799, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28470507

ABSTRACT

PURPOSE: Breast cancer (BC) diagnosis in young adults (YA) is rising, and both disease and treatments are aggressive in this population. Evidence supports the use of physical activity in reducing shoulder dysfunction, which is common among BC survivors. A pilot randomized clinical trial was performed to determine the effectiveness of a 12-week post-radiation exercise program in minimizing upper extremity dysfunction in YA with BC. METHODS: Participants were randomized to either an exercise arm or a control arm receiving standard care. Data was collected over six time points using: the Disability of Arm, Shoulder, and Hand (DASH); the Metabolic Equivalent of Task-hours per week (MET-hours/week), and a post hoc questionnaire on return to work. RESULTS: In total, 59 young women participated in the study (n = 29 exercise; n = 30 control). No statistically significant differences were found in overall DASH results between groups; however, those who underwent total mastectomy had residual upper limb dysfunction (p < 0.05). Both groups returned to pre-diagnosis activity levels by 18 months. Final evaluation showed that 86% of the women returned to work, and 89% resumed prior work activities with a decrease of 8.5 h/week. CONCLUSION: Although the short-term targeted exercise program had no effect on long-term upper limb function post-radiation, timing and program specificity may require consideration of tissue healing post-radiation and surgery type. The majority of participants returned to work, however not returning to pre-diagnosis work hours. IMPLICATIONS FOR CANCER SURVIVORS: Exercise interventions alone may not reverse the long-term sequelae of breast cancer treatment and allow young adult patients to return to work.


Subject(s)
Breast Neoplasms/rehabilitation , Exercise Therapy/methods , Return to Work/trends , Upper Extremity/physiopathology , Adolescent , Adult , Breast Neoplasms/mortality , Breast Neoplasms/radiotherapy , Female , Humans , Middle Aged , Pilot Projects , Prospective Studies , Surveys and Questionnaires , Survivors , Young Adult
5.
mBio ; 7(5)2016 09 06.
Article in English | MEDLINE | ID: mdl-27601571

ABSTRACT

UNLABELLED: Salmonella enterica pathogenicity island 1 (SPI-1) encodes proteins required for invasion of gut epithelial cells. The timing of invasion is tightly controlled by a complex regulatory network. The transcription factor (TF) HilD is the master regulator of this process and senses environmental signals associated with invasion. HilD activates transcription of genes within and outside SPI-1, including six other TFs. Thus, the transcriptional program associated with host cell invasion is controlled by at least 7 TFs. However, very few of the regulatory targets are known for these TFs, and the extent of the regulatory network is unclear. In this study, we used complementary genomic approaches to map the direct regulatory targets of all 7 TFs. Our data reveal a highly complex and interconnected network that includes many previously undescribed regulatory targets. Moreover, the network extends well beyond the 7 TFs, due to the inclusion of many additional TFs and noncoding RNAs. By comparing gene expression profiles of regulatory targets for the 7 TFs, we identified many uncharacterized genes that are likely to play direct roles in invasion. We also uncovered cross talk between SPI-1 regulation and other regulatory pathways, which, in turn, identified gene clusters that likely share related functions. Our data are freely available through an intuitive online browser and represent a valuable resource for the bacterial research community. IMPORTANCE: Invasion of epithelial cells is an early step during infection by Salmonella enterica and requires secretion of specific proteins into host cells via a type III secretion system (T3SS). Most T3SS-associated proteins required for invasion are encoded in a horizontally acquired genomic locus known as Salmonella pathogenicity island 1 (SPI-1). Multiple regulators respond to environmental signals to ensure appropriate timing of SPI-1 gene expression. In particular, there are seven transcription regulators that are known to be involved in coordinating expression of SPI-1 genes. We have used complementary genome-scale approaches to map the gene targets of these seven regulators. Our data reveal a highly complex and interconnected regulatory network that includes many previously undescribed target genes. Moreover, our data functionally implicate many uncharacterized genes in the invasion process and reveal cross talk between SPI-1 regulation and other regulatory pathways. All datasets are freely available through an intuitive online browser.


Subject(s)
Endocytosis , Epithelial Cells/microbiology , Gene Regulatory Networks , Salmonella typhimurium/genetics , Salmonella typhimurium/physiology , Gene Expression Profiling , RNA, Untranslated , Regulon , Transcription Factors/genetics
6.
Viruses ; 7(10): 5619-31, 2015 Oct 27.
Article in English | MEDLINE | ID: mdl-26516902

ABSTRACT

Complex interactions between microbial residents of mosquitoes and arboviruses are likely to influence many aspects of vectorial capacity and could potentially have profound effects on patterns of arbovirus transmission. Such interactions have not been well studied for West Nile virus (WNV; Flaviviridae, Flavivirus) and Culex spp. mosquitoes. We utilized next-generation sequencing of 16S ribosomal RNA bacterial genes derived from Culex pipiens Linnaeus following WNV exposure and/or infection and compared bacterial populations and broad immune responses to unexposed mosquitoes. Our results demonstrate that WNV infection increases the diversity of bacterial populations and is associated with up-regulation of classical invertebrate immune pathways including RNA interference (RNAi), Toll, and Jak-STAT (Janus kinase-Signal Transducer and Activator of Transcription). In addition, WNV exposure alone, without the establishment of infection, results in similar alterations to microbial and immune signatures, although to a lesser extent. Multiple bacterial genera were found in greater abundance inWNV-exposed and/or infected mosquitoes, yet the most consistent and notable was the genus Serratia.


Subject(s)
Bacteria/classification , Culex/microbiology , Culex/virology , Microbial Interactions , Signal Transduction/genetics , West Nile virus/growth & development , West Nile virus/immunology , Animals , Bacteria/genetics , Biota , Culex/immunology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Female , Gene Expression , Gene Expression Profiling , High-Throughput Nucleotide Sequencing , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
7.
J Clin Microbiol ; 53(10): 3334-40, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26269623

ABSTRACT

Salmonella enterica serovar Enteritidis is a significant cause of gastrointestinal illness in the United States; however, current molecular subtyping methods lack resolution for this highly clonal serovar. Advances in next-generation sequencing technologies have made it possible to examine whole-genome sequencing (WGS) as a potential molecular subtyping tool for outbreak detection and source trace back. Here, we conducted a retrospective analysis of S. Enteritidis isolates from seven epidemiologically confirmed foodborne outbreaks and sporadic isolates (not epidemiologically linked) to determine the utility of WGS to identify outbreaks. A collection of 55 epidemiologically characterized clinical and environmental S. Enteritidis isolates were sequenced. Single nucleotide polymorphism (SNP)-based cluster analysis of the S. Enteritidis genomes revealed well supported clades, with less than four-SNP pairwise diversity, that were concordant with epidemiologically defined outbreaks. Sporadic isolates were an average of 42.5 SNPs distant from the outbreak clusters. Isolates collected from the same patient over several weeks differed by only two SNPs. Our findings show that WGS provided greater resolution between outbreak, sporadic, and suspect isolates than the current gold standard subtyping method, pulsed-field gel electrophoresis (PFGE). Furthermore, results could be obtained in a time frame suitable for surveillance activities, supporting the use of WGS as an outbreak detection and characterization method for S. Enteritidis.


Subject(s)
Disease Outbreaks , Foodborne Diseases/epidemiology , Molecular Typing/methods , Polymorphism, Single Nucleotide , Salmonella Infections/epidemiology , Salmonella enteritidis/classification , Sequence Analysis, DNA , Cluster Analysis , Epidemiological Monitoring , Foodborne Diseases/microbiology , Genome, Bacterial , Genotype , Humans , Molecular Epidemiology/methods , Retrospective Studies , Salmonella Infections/microbiology , Salmonella enteritidis/genetics , Salmonella enteritidis/isolation & purification , United States/epidemiology
8.
G3 (Bethesda) ; 5(5): 829-38, 2015 Mar 05.
Article in English | MEDLINE | ID: mdl-25748434

ABSTRACT

Previous studies have described a transcriptional "memory effect," whereby transcript levels of many Abf1-regulated genes in the budding yeast Saccharomyces cerevisiae are undiminished even after Abf1 has dissociated from its regulatory sites. Here we provide additional support for this effect and investigate its molecular basis. We show that the effect is observed in a distinct abf1 ts mutant from that used in earlier studies, demonstrating that it is robust, and use chromatin immunoprecipitation to show that Abf1 association is decreased similarly from memory effect and transcriptionally responsive genes at the restrictive temperature. We also demonstrate that the association of TATA-binding protein and Pol II decreases after the loss of Abf1 binding for transcriptionally responsive genes but not for memory effect genes. Examination of genome-wide nucleosome occupancy data reveals that although transcriptionally responsive genes exhibit increased nucleosome occupancy in abf1 ts yeast, the promoter regions of memory effect targets show no change in abf1 ts mutants, maintaining an open chromatin conformation even after Abf1 eviction. This contrasting behavior reflects different inherent propensity for nucleosome formation between the two classes, driven by the presence of A/T-rich sequences upstream of the Abf1 site in memory effect gene promoters. These sequence-based differences show conservation in closely related fungi and also correlate with different gene expression noise, suggesting a physiological basis for greater access to "memory effect" promoter regions. Thus, our results establish a conserved mechanism underlying a transcriptional memory effect whereby sequences surrounding Abf1 binding sequences affect local nucleosome occupancy following loss of Abf1 binding. Furthermore, these findings demonstrate that sequence-based differences in the propensity for nucleosome occupancy can influence the transcriptional response of genes to an altered regulatory signal.


Subject(s)
Chromatin/genetics , Gene Expression Regulation, Fungal , Transcription, Genetic , Yeasts/genetics , Binding Sites , Chromatin/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Mutation , Nucleosomes/metabolism , Promoter Regions, Genetic , Protein Binding , Transcription Factors/metabolism , Yeasts/metabolism
9.
J Bacteriol ; 197(1): 40-50, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25313390

ABSTRACT

Interest in finding small RNAs (sRNAs) in bacteria has significantly increased in recent years due to their regulatory functions. Development of high-throughput methods and more sophisticated computational algorithms has allowed rapid identification of sRNA candidates in different species. However, given their various sizes (50 to 500 nucleotides [nt]) and their potential genomic locations in the 5' and 3' untranslated regions as well as in intergenic regions, identification and validation of true sRNAs have been challenging. In addition, the evolution of bacterial sRNAs across different species continues to be puzzling, given that they can exert similar functions with various sequences and structures. In this study, we analyzed the enrichment patterns of sRNAs in 13 well-annotated bacterial species using existing transcriptome and experimental data. All intergenic regions were analyzed by WU-BLAST to examine conservation levels relative to species within or outside their genus. In total, more than 900 validated bacterial sRNAs and 23,000 intergenic regions were analyzed. The results indicate that sRNAs are enriched in intergenic regions, which are longer and more conserved than the average intergenic regions in the corresponding bacterial genome. We also found that sRNA-coding regions have different conservation levels relative to their flanking regions. This work provides a way to analyze how noncoding RNAs are distributed in bacterial genomes and also shows conserved features of intergenic regions that encode sRNAs. These results also provide insight into the functions of regions surrounding sRNAs and into optimization of RNA search algorithms.


Subject(s)
Bacteria/genetics , Conserved Sequence/genetics , DNA, Intergenic/genetics , Gene Expression Regulation, Bacterial/physiology , Genome, Bacterial , RNA, Bacterial/genetics , Genome-Wide Association Study
10.
Mol Cell ; 56(5): 653-66, 2014 Dec 04.
Article in English | MEDLINE | ID: mdl-25457164

ABSTRACT

ATP-dependent chromatin remodelers regulate chromatin structure during multiple stages of transcription. We report that RSC, an essential chromatin remodeler, is recruited to the open reading frames (ORFs) of actively transcribed genes genome wide, suggesting a role for RSC in regulating transcription elongation. Consistent with such a role, Pol II occupancy in the ORFs of weakly transcribed genes is drastically reduced upon depletion of the RSC catalytic subunit Sth1. RSC inactivation also reduced histone H3 occupancy across transcribed regions. Remarkably, the strongest effects on Pol II and H3 occupancy were confined to the genes displaying the greatest RSC ORF enrichment. Additionally, RSC recruitment to the ORF requires the activities of the SAGA and NuA4 HAT complexes and is aided by the activities of the Pol II CTD Ser2 kinases Bur1 and Ctk1. Overall, our findings strongly implicate ORF-associated RSC in governing Pol II function and in maintaining chromatin structure over transcribed regions.


Subject(s)
DNA-Binding Proteins/metabolism , Histones/metabolism , RNA Polymerase II/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , Transcription Factors/metabolism , Chromatin Assembly and Disassembly , Gene Expression Regulation, Fungal , Open Reading Frames , Stress, Physiological , Transcription, Genetic
12.
J Bacteriol ; 196(3): 660-71, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24272778

ABSTRACT

Escherichia coli AraC is a well-described transcription activator of genes involved in arabinose metabolism. Using complementary genomic approaches, chromatin immunoprecipitation (ChIP)-chip, and transcription profiling, we identify direct regulatory targets of AraC, including five novel target genes: ytfQ, ydeN, ydeM, ygeA, and polB. Strikingly, only ytfQ has an established connection to arabinose metabolism, suggesting that AraC has a broader function than previously described. We demonstrate arabinose-dependent repression of ydeNM by AraC, in contrast to the well-described arabinose-dependent activation of other target genes. We also demonstrate unexpected read-through of transcription at the Rho-independent terminators downstream of araD and araE, leading to significant increases in the expression of polB and ygeA, respectively. AraC is highly conserved in the related species Salmonella enterica. We use ChIP sequencing (ChIP-seq) and RNA sequencing (RNA-seq) to map the AraC regulon in S. enterica. A comparison of the E. coli and S. enterica AraC regulons, coupled with a bioinformatic analysis of other related species, reveals a conserved regulatory network across the family Enterobacteriaceae comprised of 10 genes associated with arabinose transport and metabolism.


Subject(s)
AraC Transcription Factor/metabolism , Escherichia coli Proteins/metabolism , Escherichia coli/metabolism , Salmonella enterica/metabolism , AraC Transcription Factor/genetics , Arabinose , Base Sequence , Binding Sites , Chromosome Mapping , DNA, Bacterial , DNA-Directed RNA Polymerases , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Gene Expression Regulation, Bacterial/physiology , Genome, Bacterial , Regulon , Salmonella enterica/genetics
13.
PLoS Biol ; 11(7): e1001602, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23874149

ABSTRACT

Horizontal gene transfer (HGT) in bacteria generates variation and drives evolution, and conjugation is considered a major contributor as it can mediate transfer of large segments of DNA between strains and species. We previously described a novel form of chromosomal conjugation in mycobacteria that does not conform to classic oriT-based conjugation models, and whose potential evolutionary significance has not been evaluated. Here, we determined the genome sequences of 22 F1-generation transconjugants, providing the first genome-wide view of conjugal HGT in bacteria at the nucleotide level. Remarkably, mycobacterial recipients acquired multiple, large, unlinked segments of donor DNA, far exceeding expectations for any bacterial HGT event. Consequently, conjugal DNA transfer created extensive genome-wide mosaicism within individual transconjugants, which generated large-scale sibling diversity approaching that seen in meiotic recombination. We exploited these attributes to perform genome-wide mapping and introgression analyses to map a locus that determines conjugal mating identity in M. smegmatis. Distributive conjugal transfer offers a plausible mechanism for the predicted HGT events that created the genome mosaicism observed among extant Mycobacterium tuberculosis and Mycobacterium canettii species. Mycobacterial distributive conjugal transfer permits innovative genetic approaches to map phenotypic traits and confers the evolutionary benefits of sexual reproduction in an asexual organism.


Subject(s)
Conjugation, Genetic/genetics , Genes, Bacterial/genetics , Mycobacterium/genetics , Gene Transfer, Horizontal/genetics , Mosaicism , Mycobacterium tuberculosis/genetics
14.
Front Pharmacol ; 4: 57, 2013.
Article in English | MEDLINE | ID: mdl-23675348

ABSTRACT

In the last half of the century, advances in the systemic therapy of cancer, including chemotherapy, hormonal therapy, targeted therapy, and immunotherapy have been responsible for improvements in cancer related mortality in developed countries even as the population continues to age. Although such advancements have yet to benefit all cancer types, systemic therapies have led to an improvement in overall survival in both the adjuvant and metastatic setting for many cancers. With the pressure to make therapies available as soon as possible, the side-effects of systemic therapies, in particular long-term side-effects are not very well characterized and understood. Increasingly, a number of cancer types are requiring long-term and even lifelong systemic therapy. This is true for both younger and older patients with cancer and has important implications for each subset. Younger patients have an overall greater expected life-span, and as a result may suffer a greater variety of treatment related complications in the long-term, whereas older patients may develop earlier side-effects as a result of their frailty. Because the incidence of cancer in the world will increase over the next several decades and there will be more people living with cancer, it is important to have an understanding of the potential side-effects of new systemic therapies. As an introductory article, in this review series, we begin by describing some of the major advances made in systemic cancer therapy along with some of their known side-effects and we also make an attempt to describe the future of systemic cancer therapy.

15.
Genome Announc ; 1(2): e0014813, 2013 Apr 25.
Article in English | MEDLINE | ID: mdl-23618714

ABSTRACT

We report an annotated draft genome sequence of the Mycobacterium smegmatis strain MKD8. This strain acts as a recipient during conjugation with the reference M. smegmatis strain mc(2)155. While the genomes of the two strains are colinear and have similar sizes, extensive genome-wide sequence variation suggests rich diversity within the M. smegmatis clade.

16.
J Biol Chem ; 287(21): 17882-17893, 2012 May 18.
Article in English | MEDLINE | ID: mdl-22447927

ABSTRACT

ICA69 (islet cell autoantigen 69 kDa) is a protein implicated in type 1 diabetes mellitus in both the non-obese diabetic (NOD) mouse model and humans. ICA69 is encoded by the Ica1 gene on mouse chromosome 6 A1-A2. We previously reported reduced ICA69 expression in the thymus of NOD mice compared with thymus of several non-diabetic mouse strains. We propose that reduced thymic ICA69 expression could result from variations in transcriptional regulation of the gene and that polymorphisms within the Ica1 core promoter may partially determine this transcriptional variability. We characterized the functional promoter of Ica1 in NOD mice and compared it with the corresponding portions of Ica1 in non-diabetic C57BL/6 mice. Luciferase reporter constructs demonstrated that the NOD Ica1 promoter region exhibited markedly reduced luciferase expression in transiently transfected medullary thymus epithelial (mTEC(+)) and B-cell (M12)-derived cell lines. However, in a non-diabetic strain, C57BL/6, the Ica1 promoter region was transcriptionally active when transiently transfected into the same cell lines. We concomitantly identified five single nucleotide polymorphisms within the NOD Ica1 promoter. One of these single nucleotide polymorphisms increases the binding affinity for the transcription factor AIRE (autoimmune regulator), which is highly expressed in thymic epithelial cells, where it is known to play a key role regulating self-antigen expression. We conclude that polymorphisms within the NOD Ica1 core promoter may determine AIRE-mediated down-regulation of ICA69 expression in medullary thymic epithelial cells, thus providing a novel mechanistic explanation for the loss of immunologic tolerance to this self-antigen in autoimmunity.


Subject(s)
Autoantigens/biosynthesis , Diabetes Mellitus, Type 1/metabolism , Down-Regulation , Polymorphism, Single Nucleotide , Transcription Factors/metabolism , Transcription, Genetic , Animals , Autoantigens/genetics , Cell Line , Diabetes Mellitus, Type 1/genetics , Humans , Mice , Mice, Inbred NOD , Transcription Factors/genetics , AIRE Protein
17.
Nucleic Acids Res ; 39(6): 2032-44, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21081559

ABSTRACT

The packaging of eukaryotic DNA into chromatin has profound consequences for gene regulation, as well as for other DNA transactions such as recombination, replication and repair. Understanding how this packaging is determined is consequently a pressing problem in molecular genetics. DNA sequence, chromatin remodelers and transcription factors affect chromatin structure, but the scope of these influences on genome-wide nucleosome occupancy patterns remains uncertain. Here, we use high resolution tiling arrays to examine the contributions of two general regulatory factors, Abf1 and Rap1, to nucleosome occupancy in Saccharomyces cerevisiae. These factors have each been shown to bind to a few hundred promoters, but we find here that thousands of loci show localized regions of altered nucleosome occupancy within 1 h of loss of Abf1 or Rap1 binding, and that altered chromatin structure can occur via binding sites having a wide range of affinities. These results indicate that DNA-binding transcription factors affect chromatin structure, and probably dynamics, throughout the genome to a much greater extent than previously appreciated.


Subject(s)
Chromatin/chemistry , DNA-Binding Proteins/physiology , Saccharomyces cerevisiae Proteins/physiology , Saccharomyces cerevisiae/genetics , Telomere-Binding Proteins/physiology , Transcription Factors/physiology , Binding Sites , DNA-Binding Proteins/analysis , Genome, Fungal , Nucleosomes/chemistry , Promoter Regions, Genetic , Saccharomyces cerevisiae Proteins/analysis , Shelterin Complex , Telomere-Binding Proteins/analysis , Transcription Factors/analysis
18.
mBio ; 1(1)2010 May 18.
Article in English | MEDLINE | ID: mdl-20689751

ABSTRACT

The vast majority of annotated transcripts in bacteria are mRNAs. Here we identify ~1,000 antisense transcripts in the model bacterium Escherichia coli. We propose that these transcripts are generated by promiscuous transcription initiation within genes and that many of them regulate expression of the overlapping gene.

20.
Nucleic Acids Res ; 38(Web Server issue): W268-74, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20435683

ABSTRACT

The transcription of a gene from its DNA template into an mRNA molecule is the first, and most heavily regulated, step in gene expression. Especially in bacteria, regulation is typically achieved via the binding of a transcription factor (protein) or small RNA molecule to the chromosomal region upstream of a regulated gene. The protein or RNA molecule recognizes a short, approximately conserved sequence within a gene's promoter region and, by binding to it, either enhances or represses expression of the nearby gene. Since the sought-for motif (pattern) is short and accommodating to variation, computational approaches that scan for binding sites have trouble distinguishing functional sites from look-alikes. Many computational approaches are unable to find the majority of experimentally verified binding sites without also finding many false positives. Phyloscan overcomes this difficulty by exploiting two key features of functional binding sites: (i) these sites are typically more conserved evolutionarily than are non-functional DNA sequences; and (ii) these sites often occur two or more times in the promoter region of a regulated gene. The website is free and open to all users, and there is no login requirement. Address: (http://bayesweb.wadsworth.org/phyloscan/).


Subject(s)
Gene Expression Regulation , Promoter Regions, Genetic , Software , Transcription, Genetic , Binding Sites , Internet , Sequence Alignment , Sequence Analysis, DNA , Transcription Factors/metabolism , User-Computer Interface
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