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1.
World J Microbiol Biotechnol ; 40(2): 52, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38146029

ABSTRACT

Escalating proportions of industrially contaminated sites are one of the major catastrophes faced at the present time due to the industrial revolution. The difficulties associated with culturing the microbes, has been circumvent by the direct use of metagenomic analysis of various complex niches. In this study, a metagenomic approach using next generation sequencing technologies was applied to exemplify the taxonomic abundance and metabolic potential of the microbial community residing in Amlakhadi canal, Ankleshwar at two different seasons. All the metagenomes revealed a predominance of Proteobacteria phylum. However, difference was observed within class level where Gammaproteobacteria was relatively high in polluted metagenome in Summer while in Monsoon the abundance shifted to Betaproteobacteria. Similarly, significant statistical differences were obtained while comparing the genera amongst contaminated sites where Serratia, Achromobacter, Stenotrophomonas and Pseudomonas were abundant in summer season and the dominance changed to Thiobacillus, Thauera, Acidovorax, Nitrosomonas, Sulfuricurvum, Novosphingobium, Hyphomonas and Geobacter in monsoon. Further upon functional characterization, the microbiomes revealed the diverse survival mechanisms, in response to the prevailing ecological conditions (such as degradation of aromatic compounds, heavy metal resistance, oxidative stress responses and multidrug resistance efflux pumps, etc.). The results have important implications in understanding and predicting the impacts of human-induced activities on microbial communities inhabiting natural niche and their responses in coping with the fluctuating pollution load.


Subject(s)
Betaproteobacteria , Gammaproteobacteria , Microbiota , Humans , Gammaproteobacteria/genetics , Betaproteobacteria/genetics , Betaproteobacteria/metabolism , Seasons , Bacteria/metabolism , Microbiota/genetics , Organic Chemicals/metabolism
2.
Pilot Feasibility Stud ; 9(1): 159, 2023 Sep 12.
Article in English | MEDLINE | ID: mdl-37700320

ABSTRACT

BACKGROUND: Huntington's disease (HD) is an adult-onset genetic neurodegenerative condition associated with cognitive decline, motor impairments, and emotional difficulties. Anxiety affects up to 71% of HD gene expansion carriers (i.e., those with the version of the gene that causes HD) and can negatively impact quality of life, worsen other HD symptoms, and increase suicide risk. Therefore, helping people with their anxiety should be a clinical priority. A significant evidence base now exists for low-cost talking therapies for anxiety, such as guided self-help, and with people with other neurodegenerative conditions (e.g., Parkinson's disease). However, this type of intervention has not been specifically assessed with HD gene expansion carriers. METHODS: This protocol describes an exploratory randomised controlled feasibility study of a psychological intervention for anxiety for HD gene expansion carriers. The 10 session guided self-help intervention ('GUIDE-HD') is based on a blend of second and third wave cognitive behavioural models of anxiety (cognitive behaviour therapy [CBT] and acceptance and commitment therapy [ACT]) and is adapted to meet the specific needs of an HD population. This study will compare guided self-help with treatment as usual (TAU), with 15 HD gene expansion carriers randomly allocated to each group. Participants will be recruited across the UK. Quantitative data will be collected pre-intervention, immediately post-intervention, 3-month post-intervention and 6-month post-intervention. Qualitative data will be collected at one month post-intervention from participants, including HD carers. The data will be analysed to assess whether the current intervention and study design are feasible to progress to a larger randomised controlled trial. Feasibility has been defined in terms of recruitment rate, retention rate to both trial arms, intervention adherence, and acceptability of the intervention and measurement tools. DISCUSSION: Given the lack of evidenced interventions to date to support the wellbeing of people with the expanded Huntington's gene, this study will assess the feasibility of progressing this particular intervention to a full trial. To try and increase the acceptability of the intervention, a number of stakeholders, including those affected by HD and in caring roles, have been fundamental to the creation of the intervention (e.g., therapy manual, planned therapy process) to date. TRIAL REGISTRATION: Trial ID: ISRCTN47330596 . Date registered: 28/09/2022. Protocol version and date: Version 2, 09/06/22. Trial sponsor organisation and contact: Leicestershire Partnership NHS Trust (Dave Clarke). Role of sponsor: Overall responsibility for the conduct and governance of the trial. Role of funder: Review of initial research proposal.

3.
J Cosmet Dermatol ; 21(9): 3803-3808, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35841215

ABSTRACT

BACKGROUND: The uptake of topical formulations can be enhanced through laser pretreatments. Newer technologies, such as non-ablative fractional lasers (NAFLs), can target dermal tissues and spare the stratum corneum (SC), which can mitigate common side effects associated with ablative laser treatment. OBJECTIVE: To discuss the parameters of 2 NAFL pretreatment systems (1440-nm/1927-nm diode system or 1550-nm erbium-doped glass/1927-nm thulium system), which can be paired with topicals to improve their cutaneous uptake. METHODS AND MATERIALS: The parameters of the 1440-nm/1927-nm diode system and 1550-nm erbium-doped glass/1927-nm thulium system were reviewed, as well as in vivo experiments using both laser systems. RESULTS: Multiple parameters should be optimized to enhance the uptake of various topical formulations and minimize side effects, including wavelength, spot size, density, pulse duration, thermal properties, and topical formulation. Chosen therapeutic parameters must account for patient-specific factors, such as treatment indication, therapeutic area, and Fitzpatrick skin type. In vivo experiments have demonstrated that both laser systems are effective in enhancing the uptake of various topical therapies relative to untreated controls. CONCLUSION: Individualization of laser system parameters increases efficiency and minimizes risk.


Subject(s)
Laser Therapy , Lasers, Solid-State , Skin Aging , Erbium , Humans , Laser Therapy/adverse effects , Lasers, Solid-State/therapeutic use , Skin , Thulium
4.
PeerJ ; 9: e12176, 2021.
Article in English | MEDLINE | ID: mdl-34707927

ABSTRACT

This study examines the soil bacterial diversity in the Portulacaria afra-dominated succulent thicket vegetation of the Albany Subtropical Thicket biome; this biome is endemic to South Africa. The aim of the study was to compare the soil microbiomes between intact and degraded zones in the succulent thicket and identify environmental factors which could explain the community compositions. Bacterial diversity, using 16S amplicon sequencing, and soil physicochemistry were compared across three zones: intact (undisturbed and vegetated), degraded (near complete removal of vegetation due to browsing) and restored (a previously degraded area which was replanted approximately 11 years before sampling). Amplicon Sequence Variant (ASV) richness was similar across the three zones, however, the bacterial community composition and soil physicochemistry differed across the intact and degraded zones. We identified, via correlation, the potential drivers of microbial community composition as soil density, pH and the ratio of Ca to Mg. The restored zone was intermediate between the intact and degraded zones. The differences in the microbial communities appeared to be driven by the presence of plants, with plant-associated taxa more common in the intact zone. The dominant taxa in the degraded zone were cosmopolitan organisms, that have been reported globally in a wide variety of habitats. This study provides baseline information on the changes of the soil bacterial community of a spatially restricted and threatened biome. It also provides a starting point for further studies on community composition and function concerning the restoration of degraded succulent thicket ecosystems.

5.
Transpl Int ; 34(10): 1770-1775, 2021 10.
Article in English | MEDLINE | ID: mdl-34288160

ABSTRACT

As SARS-CoV-2 vaccines have started to be rolled out, a key question facing transplant units has been whether listing for transplantation should be contingent on recipients having received a vaccine. We aimed to provide an ethical framework when considering potential transplant candidates who decline vaccination. We convened a working group comprising transplant professionals, lay members and patients and undertook a literature review and consensus process. This group's work was also informed by discussions in two hospital clinical ethics committees. We have reviewed arguments for and against mandating vaccination prior to listing for kidney transplantation and considered some practical difficulties which may be associated with a policy of mandated vaccination. Rather than requiring that all patients must receive the SARS-CoV-2 vaccine prior to transplant listing, we recommend considering vaccination status as one of a number of SARS-CoV-2-related risk factors in relation to transplant listing. Transplant units should engage in individualised risk-benefit discussions with patients, avoid the language of mandated treatments and strongly encourage uptake of the vaccine in all patient groups, using tailor-made educational initiatives.


Subject(s)
COVID-19 , Kidney Transplantation , COVID-19 Vaccines , Humans , SARS-CoV-2 , Vaccination
6.
Am J Pharm Educ ; 85(9): 8493, 2021 10.
Article in English | MEDLINE | ID: mdl-34301538

ABSTRACT

Objective. Promoting equity and diversity in health care must include increasing the population of minority health care professionals. The purpose of this study was to: evaluate changes in Black professional student enrollment in schools and colleges of pharmacy, medicine, and dentistry; determine whether significant differences exist in Black professional student enrollment among these schools; and rate schools on how well Black professional student enrollment reflects state populations and compare ratings between 2010 and 2019 (for purposes of this study, professional student refers to students enrolled in Doctor of Medicine [MD], Doctor of Pharmacy [PharmD], or Doctor of Dental Medicine [DMD]/Doctor of Dental Surgery [DDS] degree programs).Methods. Enrollment data were obtained through the American Association of Colleges of Pharmacy, Association of American Medical Colleges, and American Dental Association for fall 2010 through fall 2019. The average percentage of Black students enrolled and the rate of change over time was determined. Schools were rated on their percentage of Black students relative to the percentage of Black residents in their state. Kruskal-Wallis H test, Wilcoxon signed rank tests, and chi-square tests were performed to quantify differences in enrollment and college ratings.Results. Schools of pharmacy and medicine experienced a significant increase in Black student enrollment between 2010 and 2019, but schools of dentistry did not. Pharmacy and medical schools also had significantly greater Black student enrollment in 2019 compared to dentistry. The proportion of schools of pharmacy and medicine with failing ratings decreased between 2010 and 2019.Conclusion. To facilitate improved access and limit health and health care disparities, it is important that health professions schools and colleges reflect the diversity of the patient populations they serve. Serious and intentional efforts toward diversification, inclusivity, and equity are necessary to improve Black student enrollment.


Subject(s)
Education, Pharmacy , Pharmacy , Students, Pharmacy , Dentistry , Humans , Schools, Pharmacy , Students , United States
7.
mBio ; 11(6)2020 11 03.
Article in English | MEDLINE | ID: mdl-33144374

ABSTRACT

Enhancing the generation of broadly reactive antibodies against influenza A virus (IAV) is a pertinent goal toward developing a universal IAV vaccine. While antibodies that bind conserved IAV epitopes have been identified in humans, antibodies specific for the variable epitopes are much more prevalent than antibodies recognizing conserved epitopes. It is important to define the factors that limit the generation of broadly reactive IAV antibodies in order to develop an effective universal IAV vaccine. The predominant theory is that competition within germinal centers favors the synthesis of high-affinity antibodies specific for the variable region of the virus, and limits antibodies specific for conserved IAV epitopes. Here, we show that reducing germinal center formation and removing competition with high-affinity antibodies was not sufficient to increase broadly reactive IAV antibodies or enhance protection against distinct IAV subtypes. These data disprove the prevailing hypothesis that broadly reactive IAV antibodies are rare due to competition within germinal centers, and reveal the critical need to further investigate factors that limit broadly reactive IAV antibodies. Additionally, our data show that IAV-specific IgM antibodies persist in mice in the absence of germinal centers, highlighting the protective capacity of germinal center-independent IgM antibodies, which are not typically considered when testing correlates of protection, and offer an alternate target for delivering a universal IAV vaccine.IMPORTANCE It is estimated that 250,000 to 650,000 individuals worldwide die each year from seasonal influenza A virus (IAV) infections. Current vaccines provide little protection against newly emerging strains. Thus, considerable effort is focused on enhancing the generation of broadly reactive IAV antibodies in order to develop a universal IAV vaccine. However, broadly reactive IAV antibodies are rare and the factors that limit their generation are not completely understood. Our data disprove the prevailing hypothesis that broadly reactive IAV antibodies are uncommon due to competition in the germinal centers with antibodies specific for the variable, hemagglutinin (HA) head. Understanding the factors that constrain development of antibodies specific for conserved regions of IAV is imperative for developing an effective universal IAV vaccine, which could potentially circumvent a catastrophic pandemic. These findings are significant as they highlight the importance of investigating other mechanisms that contribute to the paucity of broadly reactive IAV antibodies.


Subject(s)
Antibodies, Viral/immunology , Antibody Affinity/immunology , Germinal Center/immunology , Influenza A virus/immunology , Influenza, Human/immunology , Orthomyxoviridae Infections/immunology , Animals , Antibodies, Neutralizing , Antibody Specificity/immunology , Cross Reactions/immunology , Disease Models, Animal , Dose-Response Relationship, Immunologic , Female , Humans , Immunization, Secondary , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Immunohistochemistry , Influenza Vaccines/immunology , Influenza, Human/virology , Mice , Mice, Transgenic , Orthomyxoviridae Infections/prevention & control , Orthomyxoviridae Infections/virology
8.
Microorganisms ; 8(9)2020 Sep 21.
Article in English | MEDLINE | ID: mdl-32967081

ABSTRACT

The Antarctic continent is widely considered to be one of the most hostile biological habitats on Earth. Despite extreme environmental conditions, the ice-free areas of the continent, which constitute some 0.44% of the total continental land area, harbour substantial and diverse communities of macro-organisms and especially microorganisms, particularly in the more "hospitable" maritime regions. In the more extreme non-maritime regions, exemplified by the McMurdo Dry Valleys of South Victoria Land, nutrient cycling and ecosystem servicing processes in soils are largely driven by microbial communities. Nitrogen turnover is a cornerstone of ecosystem servicing. In Antarctic continental soils, specifically those lacking macrophytes, cold-active free-living diazotrophic microorganisms, particularly Cyanobacteria, are keystone taxa. The diazotrophs are complemented by heterotrophic bacterial and archaeal taxa which show the genetic capacity to perform elements of the entire N cycle, including nitrification processes such as the anammox reaction. Here, we review the current literature on nitrogen cycling genes, taxa, processes and rates from studies of Antarctic soils. In particular, we highlight the current gaps in our knowledge of the scale and contribution of these processes in south polar soils as critical data to underpin viable predictions of how such processes may alter under the impacts of future climate change.

9.
J Exp Bot ; 71(15): 4591-4603, 2020 07 25.
Article in English | MEDLINE | ID: mdl-32267497

ABSTRACT

Plants depend upon beneficial interactions between roots and root-associated microorganisms for growth promotion, disease suppression, and nutrient availability. This includes the ability of free-living diazotrophic bacteria to supply nitrogen, an ecological role that has been long underappreciated in modern agriculture for efficient crop production systems. Long-term ecological studies in legume-rhizobia interactions have shown that elevated nitrogen inputs can lead to the evolution of less cooperative nitrogen-fixing mutualists. Here we describe how reprogramming the genetic regulation of nitrogen fixation and assimilation in a novel root-associated diazotroph can restore ammonium production in the presence of exogenous nitrogen inputs. We isolated a strain of the plant-associated proteobacterium Kosakonia sacchari from corn roots, characterized its nitrogen regulatory network, and targeted key nodes for gene editing to optimize nitrogen fixation in corn. While the wild-type strain exhibits repression of nitrogen fixation in conditions replete with bioavailable nitrogen, such as fertilized greenhouse and field experiments, remodeled strains show elevated levels in the rhizosphere of corn in the greenhouse and field even in the presence of exogenous nitrogen. Such strains could be used in commercial applications to supply fixed nitrogen to cereal crops.


Subject(s)
Nitrogen Fixation , Nitrogenase , Enterobacteriaceae/metabolism , Nitrogen , Nitrogenase/metabolism , Zea mays/metabolism
10.
Am J Pharm Educ ; 84(2): 7561, 2020 02.
Article in English | MEDLINE | ID: mdl-32226072

ABSTRACT

Objective. To examine predictors of Doctor of Pharmacy (PharmD) students' on-time graduation, dismissal from pharmacy school, and scores on their first attempt at taking the North American Pharmacist Licensure Examination (NAPLEX). Methods. A retrospective review of student records for the graduating classes of 2015-2018 at a college of pharmacy was performed. Data on the following were collected: student demographics/characteristics (age, gender, race/ethnicity, financial need), having an undergraduate degree, undergraduate science grade point average (GPA), Pharmacy College Admission Test composite score percentile, pharmacy school GPAs for the didactic portion of the curriculum, Pre-NAPLEX score, on-time graduation from pharmacy school, dismissal from pharmacy school, and outcome (pass/fail) of first-attempt at taking the NAPLEX. Binary logistic regression analysis was conducted. Results. Of the 657 students whose records were included in the study, the majority were female (60%) and non-Hispanic white (70%). Higher first-year GPA was associated with increased likelihood of on-time graduation, while increased age and having an undergraduate degree were associated with a decreased likelihood of on-time graduation. A higher first-year GPA was associated with decreased likelihood of being dismissed from pharmacy school. Appearing before the Academic Standing and Promotion Review Committee for unsatisfactory academic performance was associated with decreased likelihood of passing the NAPLEX. Conclusion. First-year pharmacy school GPA is a critical predictor for student pharmacists in terms of on-time graduation and dismissal, and may have consequences for later NAPLEX outcome. Pharmacy schools should closely monitor students' performance during the first year and provide support to students experiencing academic difficulties.


Subject(s)
Academic Performance/statistics & numerical data , Educational Measurement/methods , Schools, Pharmacy/organization & administration , Students, Pharmacy/statistics & numerical data , Academic Success , Data Collection , Education, Pharmacy , Forecasting , Humans , Licensure, Pharmacy , Retrospective Studies
11.
PLoS One ; 14(5): e0216893, 2019.
Article in English | MEDLINE | ID: mdl-31120919

ABSTRACT

CD4+ effector/memory T cells (Tem) represent a leading edge of the adaptive immune system responsible for protecting the body from infection, cancer, and other damaging processes. However, a subset of Tem cells with low expression of CD45Rb (RbLoTem) has been shown to suppress inflammation despite their effector surface phenotype and the lack of FoxP3 expression, the canonical transcription factor found in most regulatory T cells. In this report, we show that RbLoTem cells can suppress inflammation by influencing Treg behavior. Co-culturing activated RbLoTem and Tregs induced high expression of IL-10 in vitro, and conditioned media from RbLoTem cells induced IL-10 expression in FoxP3+ Tregs in vitro and in vivo, indicating that RbLoTem cells communicate with Tregs in a cell-contact independent fashion. Transcriptomic and multi-analyte Luminex data identified both IL-2 and IL-4 as potential mediators of RbLoTem-Treg communication, and antibody-mediated neutralization of either IL-4 or CD124 (IL-4Rα) prevented IL-10 induction in Tregs. Moreover, isolated Tregs cultured with recombinant IL-2 and IL-4 strongly induced IL-10 production. Using house dust mite (HDM)-induced airway inflammation as a model, we confirmed that the in vivo suppressive activity of RbLoTem cells was lost in IL-4-ablated RbLoTem cells. These data support a model in which RbLoTem cells communicate with Tregs using a combination of IL-2 and IL-4 to induce robust expression of IL-10 and suppression of inflammation.


Subject(s)
Asthma/immunology , Cell Communication/immunology , Interleukin-10/immunology , Interleukin-4/immunology , Leukocyte Common Antigens/immunology , Models, Immunological , T-Lymphocytes, Regulatory/immunology , Animals , Asthma/genetics , Asthma/pathology , Cell Communication/genetics , Disease Models, Animal , Inflammation/genetics , Inflammation/immunology , Inflammation/pathology , Interleukin-10/genetics , Interleukin-2/genetics , Interleukin-2/immunology , Interleukin-4/genetics , Leukocyte Common Antigens/genetics , Mice , Mice, Knockout , Pyroglyphidae/immunology , T-Lymphocytes, Regulatory/pathology
12.
Glycobiology ; 28(1): 50-58, 2018 12 01.
Article in English | MEDLINE | ID: mdl-29087497

ABSTRACT

Inhibition of peripheral inflammatory disease by carbohydrate antigens derived from normal gut microbiota has been demonstrated for the GI tract, brain, peritoneum, and most recently the airway. We have demonstrated that polysaccharide A (PSA) from the commensal organism Bacteroides fragilis activates CD4+ T cells upon presentation by the class II major histocompatibility complex, and that these PSA-experienced T cells prevent the development of lung inflammation in murine models. While the PSA-responding T cells themselves are not canonical FoxP3+ regulatory T cells (Tregs), their ability to prevent inflammation is dependent upon the suppressive cytokine IL-10. Using an adoptive T cell transfer approach, we have discovered that PSA-experienced T cells require IL-10 expression by PSA-naïve recipient animals in order to prevent inflammation. A cooperative relationship was found between PSA-activated effector/memory T cells and tissue-resident FoxP3+ Tregs both in vivo and in vitro, and it is this cooperation that enables the suppressive activity of PSA outside of the gut environment where exposure takes place. These findings suggest that carbohydrate antigens from the normal microbiota communicate with peripheral tissues to maintain homeostasis through T cell-to-T cell cooperation.


Subject(s)
Forkhead Transcription Factors/immunology , Interleukin-10/immunology , Pneumonia/prevention & control , Polysaccharides/pharmacology , T-Lymphocytes, Regulatory/drug effects , Animals , Bacteroides fragilis/isolation & purification , Cells, Cultured , Mice , Mice, Inbred C57BL , Pneumonia/immunology , Pneumonia/microbiology , T-Lymphocytes, Regulatory/immunology
13.
Glycobiology ; 26(9): 1007-1013, 2016 09.
Article in English | MEDLINE | ID: mdl-27146521

ABSTRACT

Zwitterionic polysaccharide antigens such as polysaccharide A (PSA) from Bacteroides fragilis have been shown to activate CD4+ T cells upon presentation by class II major histocompatibility complex (MHCII) on professional antigen presenting cells. For T cell recognition and activation, high affinity binding between MHCII and PSA is required, and complex N-glycans on conserved MHCII asparagine residues play a central role in controlling this interaction. By truncating these glycans in a myeloid-specific knockout of Mgat2, created using the LyzM-CRE mouse (M-cKO), we previously reported defects in PSA responses in vivo. Unfortunately, the M-cKO also showed a propensity to develop common variable immunodeficiency with autoimmune hemolytic anemia features. Here, we describe a novel murine model in which Mgat2 was targeted for ablation using the dendritic cell (DC)-specific CD11c-CRE-GFP strain in order to develop a more specific and robust in vivo model of PSA presentation defects (DC-cKO). This study shows that Mgat2 deficient DCs from DC-cKO mice show ablation of PSA presentation and downstream T cell activation in vitro. However, the CD11c promoter was unexpectedly active and triggered Mgat2 deletion within multiple hematopoietic lineages, showed remarkably poor penetrance within native DC populations, and produced almost undetectable levels of green fluorescent protein signal. These findings show that the CD11c promoter is not DC-specific, and extreme care should be taken in the interpretation of data using any mouse created using the CD11c-CRE model.


Subject(s)
Antigen Presentation/genetics , CD11c Antigen/genetics , N-Acetylglucosaminyltransferases/genetics , Polysaccharides/immunology , Animals , Antigen Presentation/immunology , Bacteroides fragilis/chemistry , CD4-Positive T-Lymphocytes/immunology , Dendritic Cells/immunology , Dendritic Cells/metabolism , Gene Expression Regulation/immunology , Mice , Mice, Knockout , N-Acetylglucosaminyltransferases/immunology , Polysaccharides/chemistry , Promoter Regions, Genetic/genetics , Promoter Regions, Genetic/immunology
14.
Genome Announc ; 4(2)2016 Mar 31.
Article in English | MEDLINE | ID: mdl-27034501

ABSTRACT

Here, we present the draft genome sequence ofPaenibacillussp. strain DMB5, isolated from polluted sediments of the Kharicut Canal, Vatva, India, having a genome size of 7.5 Mbp and 7,077 coding sequences. The genome of this dye-degrading bacterium provides valuable information on the microbe-mediated biodegradation of anthropogenic compounds.

15.
Mol Microbiol ; 101(5): 743-56, 2016 09.
Article in English | MEDLINE | ID: mdl-27121483

ABSTRACT

Antibiotic selection drives adaptation of antibiotic resistance plasmids to new bacterial hosts, but the molecular mechanisms are still poorly understood. We previously showed that a broad-host-range plasmid was poorly maintained in Shewanella oneidensis, but rapidly adapted through mutations in the replication initiation gene trfA1. Here we examined if these mutations reduced the fitness cost of TrfA1, and whether this was due to changes in interaction with the host's DNA helicase DnaB. The strains expressing evolved TrfA1 variants showed a higher growth rate than those expressing ancestral TrfA1. The evolved TrfA1 variants showed a lower affinity to the helicase than ancestral TrfA1 and were no longer able to activate the helicase at the oriV without host DnaA. Moreover, persistence of the ancestral plasmid was increased upon overexpression of DnaB. Finally, the evolved TrfA1 variants generated higher plasmid copy numbers than ancestral TrfA1. The findings suggest that ancestral plasmid instability can at least partly be explained by titration of DnaB by TrfA1. Thus under antibiotic selection resistance plasmids can adapt to a novel bacterial host through partial loss of function mutations that simultaneously increase plasmid copy number and decrease unfavorably high affinity to one of the hosts' essential proteins.


Subject(s)
Escherichia coli Proteins/metabolism , Plasmids/metabolism , Shewanella/virology , DNA Helicases/metabolism , DNA Replication/genetics , DNA-Binding Proteins/metabolism , DnaB Helicases/genetics , DnaB Helicases/metabolism , Drug Resistance, Microbial , Escherichia coli/genetics , Escherichia coli/metabolism , Escherichia coli/virology , Escherichia coli Proteins/genetics , Plasmids/genetics , Shewanella/genetics
16.
Glycobiology ; 25(4): 368-75, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25347992

ABSTRACT

Over the last four decades, increases in the incidence of immune-mediated diseases in the Western world have been linked to changes in microbial exposure. It is becoming increasingly clear that the normal microbiota in the gut can profoundly alter susceptibility to a wide range of diseases, such as asthma, in which immune homeostasis is disrupted, yet the mechanisms governing this microbial influence remains poorly defined. In this study, we show that gastrointestinal exposure to PSA, a capsular polysaccharide derived from the commensal bacterium Bacteroides fragilis, significantly limits susceptibility to the induction of experimental asthma. We report that direct treatment of mice with PSA generates protection from asthma, and this effect can be given to a naïve recipient by adoptive transfer of CD4(+) T cells from PSA-exposed mice. Remarkably, we found that these PSA-induced T cells are not canonical FoxP3(+) regulatory T cells, but that they potently inhibit both Th1 and Th2 models of asthma in an IL-10-dependent fashion. These findings reveal that bacterial polysaccharides link the microbiota with the peripheral immune system by activating CD4(+)Foxp3(-) T cells upon exposure in the gut, and they facilitate resistance to unnecessary inflammatory responses via the production of IL-10.


Subject(s)
Anti-Asthmatic Agents/pharmacology , Asthma/drug therapy , Polysaccharides, Bacterial/pharmacology , Th1 Cells/drug effects , Th2 Cells/drug effects , Animals , Asthma/immunology , Drug Evaluation, Preclinical , Female , Forkhead Transcription Factors/metabolism , Interleukin-10/physiology , Lymphocyte Activation/drug effects , Male , Mice, Inbred C57BL , Mice, Transgenic , Th1 Cells/immunology , Th1 Cells/metabolism , Th2 Cells/immunology , Th2 Cells/metabolism
17.
J Biol Chem ; 290(8): 5007-5014, 2015 Feb 20.
Article in English | MEDLINE | ID: mdl-25540199

ABSTRACT

For 3 decades, the view of MHCII-dependent antigen presentation has been completely dominated by peptide antigens despite our 2004 discovery in which MHCII was shown to present processed fragments of zwitterionic capsular polysaccharides to T cells. Published findings further demonstrate that polysaccharide A (PSA) from the capsule of Bacteroides fragilis is a potent activator of CD4(+) T cells and that these T cells have important biological functions, especially in the maintenance of immunological homeostasis. However, little is known about the nature of T cell recognition of the polysaccharide-MHCII complex or the phenotype of the resulting activated cells. Here, we use next-generation sequencing of the αßT cell receptor of CD4(+) T cells from mice stimulated with PSA in comparison with protein antigen simulation and non-immunized controls and found that PSA immunization induced clonal expansion of a small subset of suppressive CD4(+)CD45RB(low) effector/memory T cells. Moreover, the sequences of the complementarity-determining region 3 (CDR3) loop from top clones indicate a lack of specific variable ß and joining region use and average CDR3 loop length. There was also a preference for a zwitterionic motif within the CDR3 loop sequences, aligning well with the known requirement for a similar motif within PSA to enable T cell activation. These data support a model in which PSA, and possibly other T cell-dependent polysaccharide antigens, elicits a clonal and therefore specific CD4(+) T cell response often characterized by pairing dual-charged CDR3 loop sequences with dual-charged PSA.


Subject(s)
Bacterial Capsules/chemistry , Bacteroides fragilis/chemistry , CD4-Positive T-Lymphocytes/immunology , Lymphocyte Activation/drug effects , Polysaccharides, Bacterial/pharmacology , Animals , CD4-Positive T-Lymphocytes/cytology , Complementarity Determining Regions/immunology , Immunologic Memory/drug effects , Mice , Polysaccharides, Bacterial/chemistry , Receptors, Antigen, T-Cell, alpha-beta/immunology
18.
Prev Chronic Dis ; 11: E97, 2014 Jun 12.
Article in English | MEDLINE | ID: mdl-24921900

ABSTRACT

State health departments in Michigan, Minnesota, Oregon, and Utah explored the use of genomic information, including family health history, in chronic disease prevention programs. To support these explorations, the Office of Public Health Genomics at the Centers for Disease Control and Prevention provided cooperative agreement funds from 2003 through 2008. The 4 states' chronic disease programs identified advocates, formed partnerships, and assessed public data; they integrated genomics into existing state plans for genetics and chronic disease prevention; they developed projects focused on prevention of asthma, cancer, cardiovascular disease, diabetes, and other chronic conditions; and they created educational curricula and materials for health workers, policymakers, and the public. Each state's program was different because of the need to adapt to existing culture, infrastructure, and resources, yet all were able to enhance their chronic disease prevention programs with the use of family health history, a low-tech "genomic tool." Additional states are drawing on the experience of these 4 states to develop their own approaches.


Subject(s)
Chronic Disease/prevention & control , Community Health Planning , Genomics/trends , Outcome Assessment, Health Care/methods , Public Health/trends , State Government , Capacity Building , Centers for Disease Control and Prevention, U.S. , Genetic Testing , Genomics/education , Human Genome Project , Humans , Leadership , Michigan , Minnesota , Oregon , Pilot Projects , Population Surveillance , Program Development , United States , Utah , Workforce
20.
J Immunol ; 190(10): 5037-47, 2013 May 15.
Article in English | MEDLINE | ID: mdl-23576679

ABSTRACT

Low-grade chronic inflammation can persist in aging humans unnoticed for years or even decades, inflicting continuous damage that can culminate later in life as organ dysfunction, physical frailty, and some of the most prominent debilitating and deadly age-associated diseases, including rheumatoid arthritis, diabetes, heart disease, and cancer. Despite the near universal acceptance of these associations, the mechanisms underlying unresolved inflammation remain poorly understood. In this study, we describe a novel inducible method to examine systemic chronic inflammation using susceptible animal models. Induced inflammation results in unresolved innate cellular responses and persistence of the same serum proinflammatory molecules used as diagnostic biomarkers and therapeutic targets for chronic inflammation in humans. Surprisingly, we found long-term persistence of an inflammation-associated neutrophil cell population constitutively producing the proinflammatory IFN-γ cytokine, which until now has only been detected transiently in acute inflammatory responses. Interestingly, these cells appear to confer T cell resistance to the otherwise potent anti-inflammatory function of myeloid-derived suppressor cells, revealing a novel mechanism for the maintenance of chronic inflammatory responses over time. This discovery represents an attractive target to resolve inflammation and prevent the inflammation-induced pathologies that are of critical concern for the well-being of the aging population.


Subject(s)
Inflammation/immunology , Interferon-gamma/biosynthesis , Neutrophils/immunology , Neutrophils/metabolism , T-Lymphocytes/immunology , Aging , Animals , Bacteroides fragilis/immunology , Biomarkers/blood , CD11b Antigen/metabolism , Cell Cycle , Disease Models, Animal , Interleukin-10/genetics , Interleukin-1beta/blood , Interleukin-6/blood , Lung/immunology , Lung/pathology , Membrane Glycoproteins/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Myeloid Cells , NADPH Oxidase 2 , NADPH Oxidases/genetics , Nitric Oxide Synthase Type II/metabolism , Receptors, Chemokine/immunology
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