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1.
Brief Bioinform ; 23(4)2022 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-35724561

RESUMO

The evolution of drug-resistant pathogenic microbial species is a major global health concern. Naturally occurring, antimicrobial peptides (AMPs) are considered promising candidates to address antibiotic resistance problems. A variety of computational methods have been developed to accurately predict AMPs. The majority of such methods are not microbial strain specific (MSS): they can predict whether a given peptide is active against some microbe, but cannot accurately calculate whether such peptide would be active against a particular MS. Due to insufficient data on most MS, only a few MSS predictive models have been developed so far. To overcome this problem, we developed a novel approach that allows to improve MSS predictive models (MSSPM), based on properties, computed for AMP sequences and characteristics of genomes, computed for target MS. New models can perform predictions of AMPs for MS that do not have data on peptides tested on them. We tested various types of feature engineering as well as different machine learning (ML) algorithms to compare the predictive abilities of resulting models. Among the ML algorithms, Random Forest and AdaBoost performed best. By using genome characteristics as additional features, the performance for all models increased relative to models relying on AMP sequence-based properties only. Our novel MSS AMP predictor is freely accessible as part of DBAASP database resource at http://dbaasp.org/prediction/genome.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Aprendizado de Máquina , Algoritmos , Peptídeos Catiônicos Antimicrobianos/genética , Bases de Dados Factuais
2.
Nucleic Acids Res ; 49(D1): D288-D297, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33151284

RESUMO

The Database of Antimicrobial Activity and Structure of Peptides (DBAASP) is an open-access, comprehensive database containing information on amino acid sequences, chemical modifications, 3D structures, bioactivities and toxicities of peptides that possess antimicrobial properties. DBAASP is updated continuously, and at present, version 3.0 (DBAASP v3) contains >15 700 entries (8000 more than the previous version), including >14 500 monomers and nearly 400 homo- and hetero-multimers. Of the monomeric antimicrobial peptides (AMPs), >12 000 are synthetic, about 2700 are ribosomally synthesized, and about 170 are non-ribosomally synthesized. Approximately 3/4 of the entries were added after the initial release of the database in 2014 reflecting the recent sharp increase in interest in AMPs. Despite the increased interest, adoption of peptide antimicrobials in clinical practice is still limited as a consequence of several factors including side effects, problems with bioavailability and high production costs. To assist in developing and optimizing de novo peptides with desired biological activities, DBAASP offers several tools including a sophisticated multifactor analysis of relevant physicochemical properties. Furthermore, DBAASP has implemented a structure modelling pipeline that automates the setup, execution and upload of molecular dynamics (MD) simulations of database peptides. At present, >3200 peptides have been populated with MD trajectories and related analyses that are both viewable within the web browser and available for download. More than 400 DBAASP entries also have links to experimentally determined structures in the Protein Data Bank. DBAASP v3 is freely accessible at http://dbaasp.org.


Assuntos
Anti-Infecciosos/química , Peptídeos Catiônicos Antimicrobianos/química , Citotoxinas/química , Bases de Dados de Proteínas , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Citotoxinas/farmacologia , Humanos , Simulação de Dinâmica Molecular , Anotação de Sequência Molecular , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta
3.
BMC Bioinformatics ; 21(1): 378, 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883210

RESUMO

BACKGROUND: The improvements in genomics methods coupled with readily accessible high-throughput sequencing have contributed to our understanding of microbial species, metagenomes, infectious diseases and more. To maximize the impact of these genomics studies, it is important that data from biological samples will become publicly available with standardized metadata. The availability of data at public archives provides the hope that greater insights could be obtained through integration with multi-omics data, reproducibility of published studies, or meta-analyses of large diverse datasets. These datasets should include a description of the host, organism, environmental source of the specimen, spatial-temporal information and other relevant metadata, but unfortunately these attributes are often missing and when present, they show inconsistencies in the use of metadata standards and ontologies. RESULTS: METAGENOTE ( https://metagenote.niaid.nih.gov ) is a web portal that greatly facilitates the annotation of samples from genomic studies and streamlines the submission process of sequencing files and metadata to the Sequence Read Archive (SRA) (Leinonen R, et al, Nucleic Acids Res, 39:D19-21, 2011) for public access. This platform offers a wide selection of packages for different types of biological and experimental studies with a special emphasis on the standardization of metadata reporting. These packages follow the guidelines from the MIxS standards developed by the Genomics Standard Consortium (GSC) and adopted by the three partners of the International Nucleotides Sequencing Database Collaboration (INSDC) (Cochrane G, et al, Nucleic Acids Res, 44:D48-50, 2016) - National Center for Biotechnology Information (NCBI), European Bioinformatics Institute (EBI) and the DNA Data Bank of Japan (DDBJ). METAGENOTE then compiles, validates and manages the submission through an easy-to-use web interface minimizing submission errors and eliminating the need for submitting sequencing files via a separate file transfer mechanism. CONCLUSIONS: METAGENOTE is a public resource that focuses on simplifying the annotation and submission process of data with its corresponding metadata. Users of METAGENOTE will benefit from the easy to use annotation interface but most importantly will be encouraged to publish metadata following standards and ontologies that make the public data available for reuse.


Assuntos
Genômica/métodos , Interface Usuário-Computador , Animais , Bases de Dados Genéticas , Humanos
4.
Bioinformatics ; 34(8): 1411-1413, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29028892

RESUMO

Motivation: Widespread interest in the study of the microbiome has resulted in data proliferation and the development of powerful computational tools. However, many scientific researchers lack the time, training, or infrastructure to work with large datasets or to install and use command line tools. Results: The National Institute of Allergy and Infectious Diseases (NIAID) has created Nephele, a cloud-based microbiome data analysis platform with standardized pipelines and a simple web interface for transforming raw data into biological insights. Nephele integrates common microbiome analysis tools as well as valuable reference datasets like the healthy human subjects cohort of the Human Microbiome Project (HMP). Nephele is built on the Amazon Web Services cloud, which provides centralized and automated storage and compute capacity, thereby reducing the burden on researchers and their institutions. Availability and implementation: https://nephele.niaid.nih.gov and https://github.com/niaid/Nephele. Contact: darrell.hurt@nih.gov.


Assuntos
Computação em Nuvem , Biologia Computacional/métodos , Microbiota/genética , Software , Humanos , Metagenômica/métodos , Análise de Sequência de DNA/métodos , Análise de Sequência de RNA
5.
J Chem Inf Model ; 58(5): 1141-1151, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29716188

RESUMO

Antimicrobial peptides (AMPs) have been identified as a potential new class of anti-infectives for drug development. There are a lot of computational methods that try to predict AMPs. Most of them can only predict if a peptide will show any antimicrobial potency, but to the best of our knowledge, there are no tools which can predict antimicrobial potency against particular strains. Here we present a predictive model of linear AMPs being active against particular Gram-negative strains relying on a semi-supervised machine-learning approach with a density-based clustering algorithm. The algorithm can well distinguish peptides active against particular strains from others which may also be active but not against the considered strain. The available AMP prediction tools cannot carry out this task. The prediction tool based on the algorithm suggested herein is available on https://dbaasp.org.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Aprendizado de Máquina , Modelos Teóricos , Análise por Conglomerados , Simulação por Computador
6.
Nucleic Acids Res ; 44(D1): D1104-12, 2016 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-26578581

RESUMO

Antimicrobial peptides (AMPs) are anti-infectives that may represent a novel and untapped class of biotherapeutics. Increasing interest in AMPs means that new peptides (natural and synthetic) are discovered faster than ever before. We describe herein a new version of the Database of Antimicrobial Activity and Structure of Peptides (DBAASPv.2, which is freely accessible at http://dbaasp.org). This iteration of the database reports chemical structures and empirically-determined activities (MICs, IC50, etc.) against more than 4200 specific target microbes for more than 2000 ribosomal, 80 non-ribosomal and 5700 synthetic peptides. Of these, the vast majority are monomeric, but nearly 200 of these peptides are found as homo- or heterodimers. More than 6100 of the peptides are linear, but about 515 are cyclic and more than 1300 have other intra-chain covalent bonds. More than half of the entries in the database were added after the resource was initially described, which reflects the recent sharp uptick of interest in AMPs. New features of DBAASPv.2 include: (i) user-friendly utilities and reporting functions, (ii) a 'Ranking Search' function to query the database by target species and return a ranked list of peptides with activity against that target and (iii) structural descriptions of the peptides derived from empirical data or calculated by molecular dynamics (MD) simulations. The three-dimensional structural data are critical components for understanding structure-activity relationships and for design of new antimicrobial drugs. We created more than 300 high-throughput MD simulations specifically for inclusion in DBAASP. The resulting structures are described in the database by novel trajectory analysis plots and movies. Another 200+ DBAASP entries have links to the Protein DataBank. All of the structures are easily visualized directly in the web browser.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bases de Dados de Produtos Farmacêuticos , Peptídeos/química , Peptídeos/farmacologia , Anti-Infecciosos/toxicidade , Citotoxinas/química , Citotoxinas/toxicidade , Simulação de Dinâmica Molecular , Peptídeos/toxicidade
7.
J Clin Microbiol ; 55(11): 3267-3282, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28904183

RESUMO

The TB Portals program is an international consortium of physicians, radiologists, and microbiologists from countries with a heavy burden of drug-resistant tuberculosis working with data scientists and information technology professionals. Together, we have built the TB Portals, a repository of socioeconomic/geographic, clinical, laboratory, radiological, and genomic data from patient cases of drug-resistant tuberculosis backed by shareable, physical samples. Currently, there are 1,299 total cases from five country sites (Azerbaijan, Belarus, Moldova, Georgia, and Romania), 976 (75.1%) of which are multidrug or extensively drug resistant and 38.2%, 51.9%, and 36.3% of which contain X-ray, computed tomography (CT) scan, and genomic data, respectively. The top Mycobacterium tuberculosis lineages represented among collected samples are Beijing, T1, and H3, and single nucleotide polymorphisms (SNPs) that confer resistance to isoniazid, rifampin, ofloxacin, and moxifloxacin occur the most frequently. These data and samples have promoted drug discovery efforts and research into genomics and quantitative image analysis to improve diagnostics while also serving as a valuable resource for researchers and clinical providers. The TB Portals database and associated projects are continually growing, and we invite new partners and collaborations to our initiative. The TB Portals data and their associated analytical and statistical tools are freely available at https://tbportals.niaid.nih.gov/.


Assuntos
Bases de Dados Factuais , Disseminação de Informação , Internet , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Europa Oriental/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Transcaucásia/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/patologia , Adulto Jovem
8.
Proc Natl Acad Sci U S A ; 111(8): 3152-7, 2014 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-24569807

RESUMO

Elicitation of broadly neutralizing antibodies is essential for the development of a protective vaccine against HIV-1. However, the native HIV-1 envelope adopts a protected conformation that conceals highly conserved sites of vulnerability from antibody recognition. Although high-definition structures of the monomeric core of the envelope glycoprotein subunit gp120 and, more recently, of a stabilized soluble gp140 trimer have been solved, fundamental aspects related to the conformation and function of the native envelope remain unresolved. Here, we show that the conserved central region of the second variable loop (V2) of gp120 contains sulfated tyrosines (Tys173 and Tys177) that in the CD4-unbound prefusion state mediate intramolecular interaction between V2 and the conserved base of the third variable loop (V3), functionally mimicking sulfated tyrosines in CCR5 and anti-coreceptor-binding-site antibodies such as 412d. Recombinant gp120 expressed in continuous cell lines displays low constitutive levels of V2 tyrosine sulfation, which can be enhanced markedly by overexpression of the tyrosyl sulfotransferase TPST2. In contrast, virion-associated gp120 produced by primary CD4(+) T cells is inherently highly sulfated. Consistent with a functional role of the V2 sulfotyrosines, enhancement of tyrosine sulfation decreased binding and neutralization of HIV-1 BaL by monomeric soluble CD4, 412d, and anti-V3 antibodies and increased recognition by the trimer-preferring antibodies PG9, PG16, CH01, and PGT145. Conversely, inhibition of tyrosine sulfation increased sensitivity to soluble CD4, 412d, and anti-V3 antibodies and diminished recognition by trimer-preferring antibodies. These results identify the sulfotyrosine-mediated V2-V3 interaction as a critical constraint that stabilizes the native HIV-1 envelope trimer and modulates its sensitivity to neutralization.


Assuntos
Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/genética , HIV-1/imunologia , Conformação Proteica , Tirosina/análogos & derivados , Western Blotting , Citometria de Fluxo , Células HEK293 , Proteína gp120 do Envelope de HIV/genética , Humanos , Testes de Neutralização , Ressonância de Plasmônio de Superfície , Tirosina/metabolismo
9.
Mol Pharmacol ; 88(5): 894-910, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26316539

RESUMO

CXCR6, the receptor for CXCL16, is expressed on multiple cell types and can be a coreceptor for human immunodeficiency virus 1. Except for CXCR6, all human chemokine receptors contain the D(3.49)R(3.50)Y(3.51) sequence, and all but two contain A(3.53) at the cytoplasmic terminus of the third transmembrane helix (H3C), a region within class A G protein-coupled receptors that contacts G proteins. In CXCR6, H3C contains D(3.49)R(3.50)F(3.51)I(3.52)V(3.53) at positions 126-130. We investigated the importance and interdependence of the canonical D126 and the noncanonical F128 and V130 in CXCR6 by mutating D126 to Y, F128 to Y, and V130 to A singly and in combination. For comparison, we mutated the analogous positions D142, Y144, and A146 to Y, F, and V, respectively, in CCR6, a related receptor containing the canonical sequences. Mutants were analyzed in both human embryonic kidney 293T and Jurkat E6-1 cells. Our data show that for CXCR6 and/or CCR6, mutations in H3C can affect both receptor signaling and chemokine binding; noncanonical H3C sequences are functionally linked, with dual changes mitigating the effects of single mutations; mutations in H3C that compromise receptor activity show selective defects in the use of individual Gi/o proteins; and the effects of mutations in H3C on receptor function and selectivity in Gi/o protein use can be cell-type specific. Our findings indicate that the ability of CXCR6 to make promiscuous use of the available Gi/o proteins is exquisitely dependent on sequences within the H3C and suggest that the native sequence allows for preservation of this function across different cellular environments.


Assuntos
Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/fisiologia , Receptores de Quimiocinas/química , Receptores Virais/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Células Cultivadas , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Células HEK293 , Humanos , Células Jurkat , Modelos Moleculares , Mutagênese , Receptores CXCR6 , Receptores de Quimiocinas/fisiologia , Receptores Virais/fisiologia , Relação Estrutura-Atividade
10.
Artigo em Inglês | MEDLINE | ID: mdl-38616847

RESUMO

The world health organization's global tuberculosis (TB) report for 2022 identifies TB, with an estimated 1.6 million, as a leading cause of death. The number of new cases has risen since 2020, particularly the number of new drug-resistant cases, estimated at 450,000 in 2021. This is concerning, as treatment of patients with drug resistant TB is complex and may not always be successful. The NIAID TB Portals program is an international consortium with a primary focus on patient centric data collection and analysis for drug resistant TB. The data includes images, their associated radiological findings, clinical records, and socioeconomic information. This work describes a TB Portals' Chest X-ray based image retrieval system which enables precision medicine. An input image is used to retrieve similar images and the associated patient specific information, thus facilitating inspection of outcomes and treatment regimens from comparable patients. Image similarity is defined using clinically relevant biomarkers: gender, age, body mass index (BMI), and the percentage of lung affected per sextant. The biomarkers are predicted using variations of the DenseNet169 convolutional neural network. A multi-task approach is used to predict gender, age and BMI incorporating transfer learning from an initial training on the NIH Clinical Center CXR dataset to the TB portals dataset. The resulting gender AUC, age and BMI mean absolute errors were 0.9854, 4.03years and 1.67kgm2. For the percentage of sextant affected by lesions the mean absolute errors ranged between 7% to 12% with higher error values in the middle and upper sextants which exhibit more variability than the lower sextants. The retrieval system is currently available from https://rap.tbportals.niaid.nih.gov/find_similar_cxr.

11.
Heliyon ; 10(6): e27852, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38560672

RESUMO

Antimicrobial peptides (AMPs) have emerged as promising candidates in combating antimicrobial resistance - a growing issue in healthcare. However, to develop AMPs into effective therapeutics, a thorough analysis and extensive investigations are essential. In this study, we employed an in silico approach to design cationic AMPs de novo, followed by their experimental testing. The antibacterial potential of de novo designed cationic AMPs, along with their synergistic properties in combination with conventional antibiotics was examined. Furthermore, the effects of bacterial inoculum density and metabolic state on the antibacterial activity of AMPs were evaluated. Finally, the impact of several potent AMPs on E. coli cell envelope and genomic DNA integrity was determined. Collectively, this comprehensive analysis provides insights into the unique characteristics of cationic AMPs.

12.
BMC Bioinformatics ; 14: 197, 2013 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-23777206

RESUMO

BACKGROUND: Influenza A viruses possess RNA genomes that mutate frequently in response to immune pressures. The mutations in the hemagglutinin genes are particularly significant, as the hemagglutinin proteins mediate attachment and fusion to host cells, thereby influencing viral pathogenicity and species specificity. Large-scale influenza A genome sequencing efforts have been ongoing to understand past epidemics and pandemics and anticipate future outbreaks. Sequencing efforts thus far have generated nearly 9,000 distinct hemagglutinin amino acid sequences. DESCRIPTION: Comparative models for all publicly available influenza A hemagglutinin protein sequences (8,769 to date) were generated using the Rosetta modeling suite. The C-alpha root mean square deviations between a randomly chosen test set of models and their crystallographic templates were less than 2 Å, suggesting that the modeling protocols yielded high-quality results. The models were compiled into an online resource, the Hemagglutinin Structure Prediction (HASP) server. The HASP server was designed as a scientific tool for researchers to visualize hemagglutinin protein sequences of interest in a three-dimensional context. With a built-in molecular viewer, hemagglutinin models can be compared side-by-side and navigated by a corresponding sequence alignment. The models and alignments can be downloaded for offline use and further analysis. CONCLUSIONS: The modeling protocols used in the HASP server scale well for large amounts of sequences and will keep pace with expanded sequencing efforts. The conservative approach to modeling and the intuitive search and visualization interfaces allow researchers to quickly analyze hemagglutinin sequences of interest in the context of the most highly related experimental structures, and allow them to directly compare hemagglutinin sequences to each other simultaneously in their two- and three-dimensional contexts. The models and methodology have shown utility in current research efforts and the ongoing aim of the HASP server is to continue to accelerate influenza A research and have a positive impact on global public health.


Assuntos
Bases de Dados de Proteínas , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Conformação Proteica , Alinhamento de Sequência , Análise de Sequência de Proteína , Software
13.
Eukaryot Cell ; 11(5): 615-25, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22467743

RESUMO

Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion. Plasmodium falciparum proteins containing TSR domains play crucial roles in parasite development. In particular, the preerythrocytic P. falciparum circumsporozoite protein is involved in hepatocyte invasion. The importance of these domains in two other malaria proteins, the merozoite-specific thrombospondin-related anonymous protein (MTRAP) and the thrombospondin-related apical membrane protein (PTRAMP), were assessed using near-full-length recombinant proteins composed of the extracellular domains produced in Escherichia coli. MTRAP is thought to be released from invasive organelles identified as micronemes during merozoite invasion to mediate motility and host cell invasion through an interaction with aldolase, an actin binding protein involved in the moving junction. PTRAMP function remains unknown. In this study, the conformation of recombinant MTRAP (rMTRAP) appeared to be a highly extended protein (2 nm by 33 nm, width by length, respectively), whereas rPTRAMP had a less extended structure. Using an erythrocyte binding assay, rMTRAP but not rPTRAMP bound human erythrocytes; rMTRAP binding was mediated through the TSR domain. MTRAP- and in general PTRAMP-specific antibodies failed to inhibit P. falciparum development in vitro. Altogether, MTRAP is a highly extended bifunctional protein that binds to an erythrocyte receptor and the merozoite motor.


Assuntos
Genes de Protozoários , Proteínas de Membrana/química , Plasmodium falciparum/química , Proteínas de Protozoários/química , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Anticorpos Antiprotozoários/imunologia , Fenômenos Biofísicos , Cromatografia Líquida de Alta Pressão/métodos , Biologia Computacional , Eritrócitos/imunologia , Eritrócitos/parasitologia , Escherichia coli/química , Frutose-Bifosfato Aldolase/química , Humanos , Glicoproteínas de Membrana/química , Proteínas de Membrana/imunologia , Microscopia de Força Atômica , Pessoa de Meia-Idade , Dados de Sequência Molecular , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/imunologia , Ligação Proteica , Redobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas de Protozoários/imunologia , Ratos , Receptores Imunológicos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Ultracentrifugação , Adulto Jovem
15.
Artigo em Inglês | MEDLINE | ID: mdl-37987019

RESUMO

Africa faces both a disproportionate burden of infectious diseases coupled with unmet needs in bioinformatics and data science capabilities which impacts the ability of African biomedical researchers to vigorously pursue research and partner with institutions in other countries. The African Centers of Excellence in Bioinformatics and Data Intensive Science are collaborating with African academic institutions, industry partners, the Foundation for the National Institutes of Health (FNIH) and the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH) in a public-private partnership to address these challenges through enhancing computational infrastructure, fostering the development of advanced bioinformatics and data science skills among local researchers and students and providing innovative emerging technologies for infectious diseases research.

16.
PLoS Pathog ; 6(11): e1001211, 2010 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-21124818

RESUMO

Antigenic drift in the influenza A virus hemagglutinin (HA) is responsible for seasonal reformulation of influenza vaccines. Here, we address an important and largely overlooked issue in antigenic drift: how does the number and location of glycosylation sites affect HA evolution in man? We analyzed the glycosylation status of all full-length H1 subtype HA sequences available in the NCBI influenza database. We devised the "flow index" (FI), a simple algorithm that calculates the tendency for viruses to gain or lose consensus glycosylation sites. The FI predicts the predominance of glycosylation states among existing strains. Our analyses show that while the number of glycosylation sites in the HA globular domain does not influence the overall magnitude of variation in defined antigenic regions, variation focuses on those regions unshielded by glycosylation. This supports the conclusion that glycosylation generally shields HA from antibody-mediated neutralization, and implies that fitness costs in accommodating oligosaccharides limit virus escape via HA hyperglycosylation.


Assuntos
Variação Antigênica/genética , Antígenos Virais/metabolismo , Variação Genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A/fisiologia , Influenza Humana/virologia , Biologia Computacional , Evolução Molecular , Glicosilação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Hemaglutininas/metabolismo , Humanos , Influenza Humana/genética , Influenza Humana/imunologia , Oligossacarídeos/metabolismo , Conformação Proteica
17.
Tuberculosis (Edinb) ; 133: 102171, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35101846

RESUMO

The TB Portals program is an international collaboration for the collection and dissemination of tuberculosis data from patient cases focused on drug resistance. The central database is a patient-oriented resource containing both patient and pathogen clinical and genomic information. Herein we provide a summary of the pathogen genomic data available through the TB Portals and show one potential application by examining patterns of genomic pairwise distances. Distributions of pairwise distances highlight overall patterns of genome variability within and between Mycobacterium tuberculosis phylogenomic lineages. Closely related isolates (based on whole-genome pairwise distances and time between sample collection dates) from different countries were identified as potential evidence of international transmission of drug-resistant tuberculosis. These high-level views of genomic relatedness provide information that can stimulate hypotheses for further and more detailed research.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Antituberculosos/uso terapêutico , Bases de Dados Factuais , Farmacorresistência Bacteriana Múltipla/genética , Genômica , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/genética , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/genética
18.
Quant Imaging Med Surg ; 12(1): 675-687, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34993110

RESUMO

BACKGROUND: Tuberculosis (TB) drug resistance is a worldwide public health problem that threatens progress made in TB care and control. Early detection of drug resistance is important for disease control, with discrimination between drug-resistant TB (DR-TB) and drug-sensitive TB (DS-TB) still being an open problem. The objective of this work is to investigate the relevance of readily available clinical data and data derived from chest X-rays (CXRs) in DR-TB prediction and to investigate the possibility of applying machine learning techniques to selected clinical and radiological features for discrimination between DR-TB and DS-TB. We hypothesize that the number of sextants affected by abnormalities such as nodule, cavity, collapse and infiltrate may serve as a radiological feature for DR-TB identification, and that both clinical and radiological features are important factors for machine classification of DR-TB and DS-TB. METHODS: We use data from the NIAID TB Portals program (https://tbportals.niaid.nih.gov), 1,455 DR-TB cases and 782 DS-TB cases from 11 countries. We first select three clinical features and 26 radiological features from the dataset. Then, we perform Pearson's chi-squared test to analyze the significance of the selected clinical and radiological features. Finally, we train machine classifiers based on different features and evaluate their ability to differentiate between DR-TB and DS-TB. RESULTS: Pearson's chi-squared test shows that two clinical features and 23 radiological features are statistically significant regarding DR-TB vs. DS-TB. A ten-fold cross-validation using a support vector machine shows that automatic discrimination between DR-TB and DS-TB achieves an average accuracy of 72.34% and an average AUC value of 78.42%, when combing all 25 statistically significant features. CONCLUSIONS: Our study suggests that the number of affected lung sextants can be used for predicting DR-TB, and that automatic discrimination between DR-TB and DS-TB is possible, with a combination of clinical features and radiological features providing the best performance.

19.
PLoS One ; 16(3): e0247906, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33730021

RESUMO

The TB Portals program provides a publicly accessible repository of TB case data containing multi-modal information such as case clinical characteristics, pathogen genomics, and radiomics. The real-world resource contains over 3400 TB cases, primarily drug resistant cases, and CT images with radiologist annotations are available for many of these cases. The breadth of data collected offers a patient-centric view into the etiology of the disease including the temporal context of the available imaging information. Here, we analyze a cohort of new TB cases with available radiologist observations of CTs taken around the time of initial registration of the case into the database and with available follow up to treatment outcome of cured or died. Follow up ranged from 5 weeks to a little over 2 years consistent with the longest treatment regimens for drug resistant TB and cases were registered within the years 2008 to 2019. The radiologist observations were incorporated into machine learning pipelines to test various class balancing strategies on the performance of predictive models. The modeling results support that the radiologist observations are predictive of treatment outcome. Moreover, inferential statistical analysis identifies markers of TB disease spread as having an association with poor treatment outcome including presence of radiologist observations in both lungs, swollen lymph nodes, multiple cavities, and large cavities. While the initial results are promising, further data collection is needed to incorporate methods to mitigate potential confounding such as including additional model covariates or matching cohorts on covariates of interest (e.g. demographics, BMI, comorbidity, TB subtype, etc.). Nonetheless, the preliminary results highlight the utility of the resource for hypothesis generation and exploration of potential biomarkers of TB disease severity and support these additional data collection efforts.


Assuntos
Pulmão/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Tuberculose/diagnóstico por imagem , Antituberculosos/uso terapêutico , Gerenciamento de Dados , Bases de Dados Factuais , Humanos , Aprendizado de Máquina , Radiologistas , Resultado do Tratamento , Tuberculose/tratamento farmacológico
20.
J Am Med Inform Assoc ; 28(1): 71-79, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33150354

RESUMO

OBJECTIVE: Clinical research informatics tools are necessary to support comprehensive studies of infectious diseases. The National Institute of Allergy and Infectious Diseases (NIAID) developed the publicly accessible Tuberculosis Data Exploration Portal (TB DEPOT) to address the complex etiology of tuberculosis (TB). MATERIALS AND METHODS: TB DEPOT displays deidentified patient case data and facilitates analyses across a wide range of clinical, socioeconomic, genomic, and radiological factors. The solution is built using Amazon Web Services cloud-based infrastructure, .NET Core, Angular, Highcharts, R, PLINK, and other custom-developed services. Structured patient data, pathogen genomic variants, and medical images are integrated into the solution to allow seamless filtering across data domains. RESULTS: Researchers can use TB DEPOT to query TB patient cases, create and save patient cohorts, and execute comparative statistical analyses on demand. The tool supports user-driven data exploration and fulfills the National Institute of Health's Findable, Accessible, Interoperable, and Reusable (FAIR) principles. DISCUSSION: TB DEPOT is the first tool of its kind in the field of TB research to integrate multidimensional data from TB patient cases. Its scalable and flexible architectural design has accommodated growth in the data, organizations, types of data, feature requests, and usage. Use of client-side technologies over server-side technologies and prioritizing maintenance have been important lessons learned. Future directions are dynamically prioritized and key functionality is shared through an application programming interface. CONCLUSION: This paper describes the platform development methodology, resulting functionality, benefits, and technical considerations of a clinical research informatics application to support increased understanding of TB.


Assuntos
Internet , Aplicações da Informática Médica , Tuberculose , Biologia Computacional , Bases de Dados como Assunto , Genômica , Humanos , National Institute of Allergy and Infectious Diseases (U.S.) , Radiologia , Software , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Tuberculose/genética , Tuberculose/prevenção & controle , Estados Unidos
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