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1.
Mol Cell ; 82(13): 2472-2489.e8, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35537449

RESUMO

Disruption of antagonism between SWI/SNF chromatin remodelers and polycomb repressor complexes drives the formation of numerous cancer types. Recently, an inhibitor of the polycomb protein EZH2 was approved for the treatment of a sarcoma mutant in the SWI/SNF subunit SMARCB1, but resistance occurs. Here, we performed CRISPR screens in SMARCB1-mutant rhabdoid tumor cells to identify genetic contributors to SWI/SNF-polycomb antagonism and potential resistance mechanisms. We found that loss of the H3K36 methyltransferase NSD1 caused resistance to EZH2 inhibition. We show that NSD1 antagonizes polycomb via cooperation with SWI/SNF and identify co-occurrence of NSD1 inactivation in SWI/SNF-defective cancers, indicating in vivo relevance. We demonstrate that H3K36me2 itself has an essential role in the activation of polycomb target genes as inhibition of the H3K36me2 demethylase KDM2A restores the efficacy of EZH2 inhibition in SWI/SNF-deficient cells lacking NSD1. Together our data expand the mechanistic understanding of SWI/SNF and polycomb interplay and identify NSD1 as the key for coordinating this transcriptional control.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste , Proteínas F-Box , Histona-Lisina N-Metiltransferase , Histona Desmetilases com o Domínio Jumonji , Proteínas do Grupo Polycomb , Proteína SMARCB1 , Cromatina/genética , Cromatina/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/metabolismo , Tumor Rabdoide/genética , Tumor Rabdoide/metabolismo , Tumor Rabdoide/patologia , Proteína SMARCB1/genética , Proteína SMARCB1/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética , Células Tumorais Cultivadas/metabolismo
2.
Brief Bioinform ; 23(5)2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36070623

RESUMO

Assessment of protective or harmful T cell response induced by any antigenic epitope is important in designing any immunotherapeutic molecule. The understanding of cytokine induction potential also helps us to monitor antigen-specific cellular immune responses and rational vaccine design. The classical immunoinformatics tools served well for prediction of B cell and T cell epitopes. However, in the last decade, the prediction algorithms for T cell epitope inducing specific cytokines have also been developed and appreciated in the scientific community. This review summarizes the current status of such tools, their applications, background algorithms, their use in experimental setup and functionalities available in the tools/web servers.


Assuntos
Epitopos de Linfócito T , Vacinas , Linfócitos B , Biologia Computacional , Citocinas , Linfócitos T
3.
J Natl Compr Canc Netw ; 21(10): 1097-1105, 2023 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-37643637

RESUMO

Medulloblastoma in infants and young children is a major challenge to treat because craniospinal irradiation (CSI), a cornerstone of therapy for older children, is disproportionately damaging to very young children. As a result, trials have attempted to delay, omit, and replace this therapy. Although success has been limited, the approach has not been a complete failure. In fact, this approach has cured a significant number of children with medulloblastoma. However, many children have endured intensive regimens of chemotherapy only to experience relapse and undergo salvage treatment with CSI, often at higher doses and with worse morbidity than they would have initially experienced. Recent advancements in molecular diagnostics have proven that response to therapy is biologically driven. Medulloblastoma in infants and young children is divided into 2 molecular groups: Sonic Hedgehog (SHH) and group 3 (G3). Both are chemotherapy-sensitive, but only the SHH medulloblastomas are reliably cured with chemotherapy alone. Moreover, SHH can be molecularly parsed into 2 groups: SHH-1 and SHH-2, with SHH-2 showing higher cure rates with less intensive chemotherapy and SHH-1 requiring more intensive regimens. G3 medulloblastoma, on the other hand, has a near universal relapse rate after chemotherapy-only regimens. This predictability represents a significant breakthrough and affords oncologists the ability to properly risk-stratify therapy in such a way that the most curative and least toxic therapy is selected. This review examines the treatment of medulloblastoma in infants and young children, discusses the molecular advancements, and proposes how to use this information to structure the future management of this disease.


Assuntos
Neoplasias Cerebelares , Meduloblastoma , Criança , Lactente , Humanos , Adolescente , Pré-Escolar , Meduloblastoma/diagnóstico , Meduloblastoma/genética , Meduloblastoma/terapia , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/terapia , Proteínas Hedgehog/genética , Proteínas Hedgehog/uso terapêutico , Recidiva Local de Neoplasia , Recidiva
4.
Pharmacoepidemiol Drug Saf ; 32(1): 78-83, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35713281

RESUMO

PURPOSE: As part of the European risk management plan of a 91-day extended levonorgestrel-containing combined oral contraceptive (COCLNG ), a study was performed to assess its safety. This analysis was conducted to examine delayed pregnancy detection and return to fertility with extended combined oral contraceptives (COC). METHODS: We conducted a retrospective cohort study in new users of 91-day COCLNG or 28-day COCLNG within a US-based healthcare claims database from 2006 to 2017. Delayed pregnancy detection during current COCLNG exposure was defined as the time between estimated pregnancy start and first prenatal care encounter. Additionally, the time between estimated pregnancy start and COCLNG discontinuation was measured. To measure return to fertility, pregnancy rates were estimated among females who discontinued treatment. 91-day COCLNG users were propensity score-matched to 28-day COCLNG users. Hazard ratio for pregnancy was calculated using Cox proportional hazards models. RESULTS: The 91-day and 28-day COCLNG users had 25 593 and 76 586 treatment episodes, respectively. The median time to pregnancy detection was 64.5 and 61.0 days (p = 0.24) in users of 91-day COCLNG and 28-day COCLNG . The median exposure time to treatment after estimated pregnancy start was 54.0 and 38.0 days (p < 0.01). In the fertility analysis, pregnancy rates were 54.82 (95% CI, 50.05-59.93) and 69.30 (95% CI, 64.98-73.82) per 1000 person-years in extended COCLNG discontinuers and 28-day COCLNG discontinuers. The adjusted hazard ratio of pregnancy was 0.77 (95% CI, 0.69-0.85). CONCLUSIONS: Small differences were observed for pregnancy rates and delayed pregnancy detection between 91-day extended COCLNG and 28-day COCLNG , which may be related to the longer days' supply of extended COCLNG . Differences in the fertility analysis may be related to unmeasured residual confounding.


Assuntos
Anticoncepcionais Orais Combinados , Levanogestrel , Gravidez , Feminino , Humanos , Levanogestrel/efeitos adversos , Estudos de Coortes , Estudos Retrospectivos , Fertilidade
5.
J Med Genet ; 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768194

RESUMO

BACKGROUND: Little is known about risks associated with germline SUFU pathogenic variants (PVs) known as a cancer predisposition syndrome. METHODS: To study tumour risks, we have analysed data of a large cohort of 45 unpublished patients with a germline SUFU PV completed with 127 previously published patients. To reduce the ascertainment bias due to index patient selection, the risk of tumours was evaluated in relatives with SUFU PV (89 patients) using the Nelson-Aalen estimator. RESULTS: Overall, 117/172 (68%) SUFU PV carriers developed at least one tumour: medulloblastoma (MB) (86 patients), basal cell carcinoma (BCC) (25 patients), meningioma (20 patients) and gonadal tumours (11 patients). Thirty-three of them (28%) had multiple tumours. Median age at diagnosis of MB, gonadal tumour, first BCC and first meningioma were 1.5, 14, 40 and 44 years, respectively. Follow-up data were available for 160 patients (137 remained alive and 23 died). The cumulative incidence of tumours in relatives was 14.4% (95% CI 6.8 to 21.4), 18.2% (95% CI 9.7 to 25.9) and 44.1% (95% CI 29.7 to 55.5) at the age of 5, 20 and 50 years, respectively. The cumulative risk of an MB, gonadal tumour, BCC and meningioma at age 50 years was: 13.3% (95% CI 6 to 20.1), 4.6% (95% CI 0 to 9.7), 28.5% (95% CI 13.4 to 40.9) and 5.2% (95% CI 0 to 12), respectively. Sixty-four different PVs were reported across the entire SUFU gene and inherited in 73% of cases in which inheritance could be evaluated. CONCLUSION: Germline SUFU PV carriers have a life-long increased risk of tumours with a spectrum dominated by MB before the age of 5, gonadal tumours during adolescence and BCC and meningioma in adulthood, justifying fine-tuned surveillance programmes.

6.
J Virol ; 95(21): e0094021, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34379494

RESUMO

Despite the prevalence and medical significance of human cytomegalovirus (HCMV) infections, a systematic analysis of the targets of T cell recognition in humans that spans the entire genome and includes recently described potential novel open reading frames (ORFs) is not available. Here, we screened a library of epitopes predicted to bind HLA class II that spans over 350 different HCMV ORFs and includes ∼150 previously described and ∼200 recently described potential novel ORFs by using an ex vivo gamma interferon (IFN-γ) FluoroSpot assay. We identified 235 unique HCMV-specific epitopes derived from 100 ORFs, some previously described as immunodominant and others that were not previously described to be immunogenic. Of those, 41 belong to the set of recently reported novel ORFs, thus providing evidence that at least some of these are actually expressed in vivo in humans. These data reveal that the breadth of the human T cell response to HCMV is much greater than previously thought. The ORFs and epitopes identified will help elucidate how T cell immunity relates to HCMV pathogenesis and instruct ongoing HCMV vaccine research. IMPORTANCE To understand the crucial role of adaptive immunity in controlling cytomegalovirus infection and disease, we systematically analyzed the CMV "ORFeome" to identify new CMV epitopes targeted primarily by CD4 T cells in humans. Our study identified >200 new T cell epitopes derived from both canonical and novel ORFs, highlighting the substantial breadth of the anti-CMV T cell response and providing new targets for vaccine design.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/genética , Citomegalovirus/imunologia , Epitopos de Linfócito T/imunologia , Fases de Leitura Aberta/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Citomegalovirus/virologia , Epitopos de Linfócito T/genética , Feminino , Humanos , Interferon gama , Masculino , Pessoa de Meia-Idade
7.
BMC Microbiol ; 22(1): 74, 2022 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-35277125

RESUMO

BACKGROUND: Malaria is a life-threatening disease caused by protozoan parasite of genus Plasmodium. Various antigenic proteins of Plasmodium are considered as the major targets for the development of an effective vaccine. The aim of the current study was a comprehensive analysis of the experimentally validated epitopes of Plasmodium obtained from various immunoassays. METHODS: Plasmodium species epitopes were prefetched from Immune Epitope Database (IEDB). Species specific classification of available epitopes was done for both human and murine malaria parasites. Further, these T cell and B cell epitopes along with MHC I/II binders of different Plasmodium species were examined to find out their capability to induce IFN-γ and IL-10 using IFNepitope and IL-10 Pred, respectively. RESULTS: The species-specific classification of 6874 unique epitopes resulted in the selection of predominant human and murine Plasmodium species. Further, the attempt was made to analyse the immune reactivity of these epitopes for their ability to induce cytokines namely IFN-γ and IL-10. Total, 2775 epitopes were predicted to possess IFN-γ inducing ability, whereas 1275 epitopes were found to be involved in the induction of IL-10. CONCLUSIONS: This study facilitates the assessment of Plasmodium epitopes and associated proteins as a potential approach to design and develop an epitope-based vaccine. Moreover, the results highlight the epitope-based immunization in malaria to induce a protective immune response.


Assuntos
Malária , Plasmodium , Animais , Antígenos de Protozoários , Epitopos de Linfócito T , Humanos , Interleucina-10 , Camundongos , Plasmodium falciparum , Proteínas de Protozoários
8.
Acta Neuropathol ; 144(4): 733-746, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35982322

RESUMO

Methylation profiling has radically transformed our understanding of tumors previously called central nervous system primitive neuro-ectodermal tumors (CNS-PNET). While this marks a momentous step toward defining key differences, reclassification has thrown treatment into disarray. To shed light on response to therapy and guide clinical decision-making, we report outcomes and molecular features of children with CNS-PNETs from two multi-center risk-adapted studies (SJMB03 for patients ≥ 3 years; SJYC07 for patients < 3 years) complemented by a non-protocol institutional cohort. Seventy patients who had a histological diagnosis of CNS-PNET or CNS embryonal tumor from one of the new categories that has supplanted CNS-PNET were included. This cohort was molecularly characterized by DNA methylation profiling (n = 70), whole-exome sequencing (n = 53), RNA sequencing (n = 20), and germline sequencing (n = 28). Clinical characteristics were detailed, and treatment was divided into craniospinal irradiation (CSI)-containing (SJMB03 and SJMB03-like) and CSI-sparing therapy (SJYC07 and SJYC07-like). When the cohort was analyzed in its entirety, no differences were observed in the 5-year survival rates even when CSI-containing therapy was compared to CSI-sparing therapy. However, when analyzed by DNA methylation molecular grouping, significant survival differences were observed, and treatment particulars provided suggestions of therapeutic response. Patients with CNS neuroblastoma with FOXR2 activation (CNS-NB-FOXR2) had a 5-year event-free survival (EFS)/overall survival (OS) of 66.7% ± 19.2%/83.3% ± 15.2%, and CIC rearranged sarcoma (CNS-SARC-CIC) had a 5-year EFS/OS both of 57.1% ± 18.7% with most receiving regimens that contained radiation (focal or CSI) and multidrug chemotherapy. Patients with high-grade neuroepithelial tumor with BCOR alteration (HGNET-BCOR) had abysmal responses to upfront chemotherapy-only regimens (5-year EFS = 0%), but survival extended with salvage radiation after progression [5-year OS = 53.6% ± 20.1%]. Patients with embryonal tumor with multilayered rosettes (ETMR) or high-grade glioma/glioblastoma multiforme (HGG/GBM) did not respond favorably to any modality (5-year EFS/OS = 10.7 ± 5.8%/17.9 ± 7.2%, and 10% ± 9.0%/10% ± 9.0%, respectively). As an accompaniment, we have assembled this data onto an interactive website to allow users to probe and query the cases. By reporting on a carefully matched clinical and molecular cohort, we provide the needed insight for future clinical management.


Assuntos
Neoplasias Encefálicas , Neoplasias do Sistema Nervoso Central , Glioblastoma , Neoplasias Embrionárias de Células Germinativas , Tumores Neuroectodérmicos Primitivos , Neoplasias Encefálicas/terapia , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/terapia , Criança , Fatores de Transcrição Forkhead , Hospitais , Humanos , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Embrionárias de Células Germinativas/terapia
9.
J Virol ; 94(10)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132233

RESUMO

Members of the flavivirus genus share a high level of sequence similarity and often circulate in the same geographical regions. However, whether T cells induced by one viral species cross-react with other related flaviviruses has not been globally addressed. In this study, we tested pools of epitopes derived from dengue (DENV), Zika (ZIKV), Japanese encephalitis (JEV), West Nile (WNV), and yellow fever (YFV) viruses by intracellular cytokine staining (ICS) using peripheral blood mononuclear cells (PBMCs) of individuals naturally exposed to DENV or immunized with DENV (TV005) or YF17D vaccine. CD8 T cell responses recognized epitopes from multiple flaviviruses; however, the magnitude of cross-reactive responses was consistently severalfold lower than those to the autologous epitope pools and was associated with lower expression of activation markers such as CD40L, CD69, and CD137. Next, we characterized the antigen sensitivity of short-term T cell lines (TCL) representing 29 different individual epitope/donor combinations. TCL derived from DENV monovalent vaccinees induced CD8 and CD4 T cells that cross-reacted within the DENV serocomplex but were consistently associated with >100-fold-lower antigen sensitivity for most other flaviviruses, with no cross-recognition of YFV-derived peptides. CD8 and CD4 TCL from YF17D vaccinees were associated with very limited cross-reactivity with any other flaviviruses and in five out of eight cases >1,000-fold-lower antigen sensitivity. Overall, our data suggest limited cross-reactivity for both CD4 and CD8 T cell responses between flaviviruses and have implications for understanding immunity elicited by natural infection and strategies to develop live attenuated vaccines against flaviviral species.IMPORTANCE The envelope (E) protein is the dominant target of neutralizing antibodies for dengue virus (DENV) and yellow fever virus (YFV). Accordingly, several DENV vaccine constructs use the E protein in a live attenuated vaccine format, utilizing a backbone derived from a heterologous flavivirus (such as YF) as a delivery vector. This backbone comprises the nonstructural (NS) and capsid (C) antigens, which are dominant targets of T cell responses. Here, we demonstrate that cross-reactivity at the level of T cell responses among different flaviviruses is very limited, despite high levels of sequence homology. Thus, the use of heterologous flavivirus species as a live attenuated vaccine vector is not likely to generate optimal T cell responses and might thus impair vaccine performance.


Assuntos
Reações Cruzadas/imunologia , Infecções por Flavivirus/imunologia , Flavivirus/imunologia , Vacinação , Vacinas Atenuadas/imunologia , Vacinas Virais/imunologia , Adolescente , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos/imunologia , Dengue/imunologia , Dengue/prevenção & controle , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Encefalite Japonesa/imunologia , Encefalite Japonesa/prevenção & controle , Epitopos de Linfócito T/genética , Feminino , Infecções por Flavivirus/prevenção & controle , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Homologia de Sequência , Febre do Nilo Ocidental/imunologia , Febre do Nilo Ocidental/prevenção & controle , Febre Amarela/imunologia , Febre Amarela/prevenção & controle , Vacina contra Febre Amarela , Vírus da Febre Amarela/imunologia , Adulto Jovem , Zika virus/imunologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/prevenção & controle
10.
Nucleic Acids Res ; 47(D1): D339-D343, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30357391

RESUMO

The Immune Epitope Database (IEDB, iedb.org) captures experimental data confined in figures, text and tables of the scientific literature, making it freely available and easily searchable to the public. The scope of the IEDB extends across immune epitope data related to all species studied and includes antibody, T cell, and MHC binding contexts associated with infectious, allergic, autoimmune, and transplant related diseases. Having been publicly accessible for >10 years, the recent focus of the IEDB has been improved query and reporting functionality to meet the needs of our users to access and summarize data that continues to grow in quantity and complexity. Here we present an update on our current efforts and future goals.


Assuntos
Bases de Dados de Proteínas , Epitopos/genética , Anticorpos/genética , Antígenos/genética , Doenças Autoimunes/genética , Curadoria de Dados , Epitopos/imunologia , Previsões , Ontologia Genética , Humanos , Hipersensibilidade/genética , Infecções/genética , Receptores de Antígenos de Linfócitos T/genética , Imunologia de Transplantes , Interface Usuário-Computador
11.
Nucleic Acids Res ; 47(W1): W502-W506, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31114900

RESUMO

The Immune Epitope Database Analysis Resource (IEDB-AR, http://tools.iedb.org/) is a companion website to the IEDB that provides computational tools focused on the prediction and analysis of B and T cell epitopes. All of the tools are freely available through the public website and many are also available through a REST API and/or a downloadable command-line tool. A virtual machine image of the entire site is also freely available for non-commercial use and contains most of the tools on the public site. Here, we describe the tools and functionalities that are available in the IEDB-AR, focusing on the 10 new tools that have been added since the last report in the 2012 NAR webserver edition. In addition, many of the tools that were already hosted on the site in 2012 have received updates to newest versions, including NetMHC, NetMHCpan, BepiPred and DiscoTope. Overall, this IEDB-AR update provides a substantial set of updated and novel features for epitope prediction and analysis.


Assuntos
Epitopos de Linfócito B/química , Epitopos de Linfócito T/química , Software , Animais , Bases de Dados de Proteínas , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Antígenos de Histocompatibilidade/metabolismo , Humanos , Camundongos
13.
Brief Bioinform ; 18(3): 467-478, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27016393

RESUMO

The conventional approach for designing vaccine against a particular disease involves stimulation of the immune system using the whole pathogen responsible for the disease. In the post-genomic era, a major challenge is to identify antigenic regions or epitopes that can stimulate different arms of the immune system. In the past two decades, numerous methods and databases have been developed for designing vaccine or immunotherapy against various pathogen-causing diseases. This review describes various computational resources important for designing subunit vaccines or epitope-based immunotherapy. First, different immunological databases are described that maintain epitopes, antigens and vaccine targets. This is followed by in silico tools used for predicting linear and conformational B-cell epitopes required for activating humoral immunity. Finally, information on T-cell epitope prediction methods is provided that includes indirect methods like prediction of Major Histocompatibility Complex and transporter-associated protein binders. Different studies for validating the predicted epitopes are also examined critically. This review enlists novel in silico resources and tools available for predicting humoral and cell-mediated immune potential. These predicted epitopes could be used for designing epitope-based vaccines or immunotherapy as they may activate the adaptive immunity. Authors emphasized the need to develop tools for the prediction of adjuvants to activate innate and adaptive immune system simultaneously. In addition, attention has also been given to novel prediction methods to predict general therapeutic properties of peptides like half-life, cytotoxicity and immune toxicity.


Assuntos
Biologia Computacional , Epitopos de Linfócito B , Epitopos de Linfócito T , Humanos , Peptídeos , Vacinas de Subunidades Antigênicas
14.
Bioinformatics ; 34(22): 3931-3933, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-29878047

RESUMO

Motivation: Datasets that are derived from different studies (e.g. MHC ligand elution, MHC binding, B/T cell epitope screening etc.) often vary in terms of experimental approaches, sizes of peptides tested, including partial and or nested overlapping peptides and in the number of donors tested. Results: We present a customized application of the Immune Epitope Database's ImmunomeBrowser tool, which can be used to effectively aggregate and visualize heterogeneous immunological data. User provided peptide sets and associated response data is mapped to a user-provided protein reference sequence. The output consists of tables and figures representing the aggregated data represented by a Response Frequency score and associated estimated confidence interval. This allows the user to visualizing regions associated with dominant responses and their boundaries. The results are presented both as a user interactive javascript based web interface and a tabular format in a selected reference sequence. Availability and implementation: The 'ImmunomeBrowser' has been a longstanding feature of the IEDB (http://www.iedb.org). The present application extends the use of this tool to work with user-provided datasets, rather than the output of IEDB queries. This new server version of the ImmunomeBrowser is freely accessible at http://tools.iedb.org/immunomebrowser/.


Assuntos
Bases de Dados de Proteínas , Epitopos/química , Peptídeos , Proteínas/química , Software , Sequência de Aminoácidos , Biologia Computacional , Ligantes
15.
Immunology ; 153(1): 118-132, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28833085

RESUMO

Unwanted immune responses against protein therapeutics can reduce efficacy or lead to adverse reactions. T-cell responses are key in the development of such responses, and are directed against immunodominant regions within the protein sequence, often associated with binding to several allelic variants of HLA class II molecules (promiscuous binders). Herein, we report a novel computational strategy to predict 'de-immunized' peptides, based on previous studies of erythropoietin protein immunogenicity. This algorithm (or method) first predicts promiscuous binding regions within the target protein sequence and then identifies residue substitutions predicted to reduce HLA binding. Further, this method anticipates the effect of any given substitution on flanking peptides, thereby circumventing the creation of nascent HLA-binding regions. As a proof-of-principle, the algorithm was applied to Vatreptacog α, an engineered Factor VII molecule associated with unintended immunogenicity. The algorithm correctly predicted the two immunogenic peptides containing the engineered residues. As a further validation, we selected and evaluated the immunogenicity of seven substitutions predicted to simultaneously reduce HLA binding for both peptides, five control substitutions with no predicted reduction in HLA-binding capacity, and additional flanking region controls. In vitro immunogenicity was detected in 21·4% of the cultures of peptides predicted to have reduced HLA binding and 11·4% of the flanking regions, compared with 46% for the cultures of the peptides predicted to be immunogenic. This method has been implemented as an interactive application, freely available online at http://tools.iedb.org/deimmunization/.


Assuntos
Proteínas de Transporte/imunologia , Proteínas de Transporte/metabolismo , Simulação por Computador , Mapeamento de Epitopos/métodos , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/metabolismo , Antígenos HLA/imunologia , Antígenos HLA/metabolismo , Alelos , Sequência de Aminoácidos , Substituição de Aminoácidos , Epitopos de Linfócito T/química , Eritropoetina/química , Eritropoetina/imunologia , Eritropoetina/metabolismo , Antígenos HLA/genética , Humanos , Epitopos Imunodominantes/imunologia , Epitopos Imunodominantes/metabolismo , Ligação Proteica/imunologia , Reprodutibilidade dos Testes , Software , Interface Usuário-Computador
16.
Immunology ; 155(3): 331-345, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30014462

RESUMO

Epitopes identified in large-scale screens of overlapping peptides often share significant levels of sequence identity, complicating the analysis of epitope-related data. Clustering algorithms are often used to facilitate these analyses, but available methods are generally insufficient in their capacity to define biologically meaningful epitope clusters in the context of the immune response. To fulfil this need we developed an algorithm that generates epitope clusters based on representative or consensus sequences. This tool allows the user to cluster peptide sequences on the basis of a specified level of identity by selecting among three different method options. These include the 'clique method', in which all members of the cluster must share the same minimal level of identity with each other, and the 'connected graph method', in which all members of a cluster must share a defined level of identity with at least one other member of the cluster. In cases where it is not possible to define a clear consensus sequence with the connected graph method, a third option provides a novel 'cluster-breaking algorithm' for consensus sequence driven sub-clustering. Herein we demonstrate the tool's clustering performance and applicability using (i) a selection of dengue virus epitopes for the 'clique method', (ii) sets of allergen-derived peptides from related species for the 'connected graph method' and (iii) large data sets of eluted ligand, major histocompatibility complex binding and T-cell recognition data captured within the Immune Epitope Database (IEDB) with the newly developed 'cluster-breaking algorithm'. This novel clustering tool is accessible at http://tools.iedb.org/cluster2/.


Assuntos
Algoritmos , Bases de Dados de Proteínas , Epitopos , Peptídeos , Análise de Sequência de Proteína/métodos , Animais , Epitopos/química , Epitopos/genética , Camundongos , Peptídeos/química , Peptídeos/genética , Ratos
17.
Nucleic Acids Res ; 44(D1): D1119-26, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26527728

RESUMO

SATPdb (http://crdd.osdd.net/raghava/satpdb/) is a database of structurally annotated therapeutic peptides, curated from 22 public domain peptide databases/datasets including 9 of our own. The current version holds 19192 unique experimentally validated therapeutic peptide sequences having length between 2 and 50 amino acids. It covers peptides having natural, non-natural and modified residues. These peptides were systematically grouped into 10 categories based on their major function or therapeutic property like 1099 anticancer, 10585 antimicrobial, 1642 drug delivery and 1698 antihypertensive peptides. We assigned or annotated structure of these therapeutic peptides using structural databases (Protein Data Bank) and state-of-the-art structure prediction methods like I-TASSER, HHsearch and PEPstrMOD. In addition, SATPdb facilitates users in performing various tasks that include: (i) structure and sequence similarity search, (ii) peptide browsing based on their function and properties, (iii) identification of moonlighting peptides and (iv) searching of peptides having desired structure and therapeutic activities. We hope this database will be useful for researchers working in the field of peptide-based therapeutics.


Assuntos
Bases de Dados de Produtos Farmacêuticos , Peptídeos/química , Peptídeos/uso terapêutico , Anti-Hipertensivos/farmacologia , Antineoplásicos/farmacologia , Anotação de Sequência Molecular , Peptídeos/farmacologia
18.
BMC Microbiol ; 16: 96, 2016 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-27230105

RESUMO

BACKGROUND: Carotenoids have important functions in bacteria, ranging from harvesting light energy to neutralizing oxidants and acting as virulence factors. However, information pertaining to the carotenoids is scattered throughout the literature. Furthermore, information about the genes/proteins involved in the biosynthesis of carotenoids has tremendously increased in the post-genomic era. A web server providing the information about microbial carotenoids in a structured manner is required and will be a valuable resource for the scientific community working with microbial carotenoids. RESULTS: Here, we have created a manually curated, open access, comprehensive compilation of bacterial carotenoids named as ProCarDB- Prokaryotic Carotenoid Database. ProCarDB includes 304 unique carotenoids arising from 50 biosynthetic pathways distributed among 611 prokaryotes. ProCarDB provides important information on carotenoids, such as 2D and 3D structures, molecular weight, molecular formula, SMILES, InChI, InChIKey, IUPAC name, KEGG Id, PubChem Id, and ChEBI Id. The database also provides NMR data, UV-vis absorption data, IR data, MS data and HPLC data that play key roles in the identification of carotenoids. An important feature of this database is the extension of biosynthetic pathways from the literature and through the presence of the genes/enzymes in different organisms. The information contained in the database was mined from published literature and databases such as KEGG, PubChem, ChEBI, LipidBank, LPSN, and Uniprot. The database integrates user-friendly browsing and searching with carotenoid analysis tools to help the user. We believe that this database will serve as a major information centre for researchers working on bacterial carotenoids.


Assuntos
Vias Biossintéticas , Carotenoides/biossíntese , Bases de Dados Genéticas , Bactérias/genética , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/química , Carotenoides/química , Mineração de Dados , Genes Bacterianos , Interface Usuário-Computador , Navegador
19.
Front Pharmacol ; 15: 1107185, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38510649

RESUMO

Background: Flurbiprofen 8.75 mg lozenges and oromucosal sprays are used for symptomatic relief of sore throat in patients aged 12 years and over. The documented adverse events of flurbiprofen use include those related to its pharmacological actions, namely, increased risk of haemorrhagic events, however other adverse events (such as nephrotoxicity and cardiac failure) have been known to occur. The likelihood of occurrence of adverse events increases when flurbiprofen is used concomitantly with some other medications. Therefore, the objective of this systematic review was to collate the current evidence on adverse events which occur with flurbiprofen 8.75 mg dose (any formulation), in particular as a result of interaction with other medicinal products, with a focus on non-haemorrhagic events. Methods: Systematic searches of the literature were conducted to identify literature on any formulation of flurbiprofen 8.75 mg up to the date of the electronic database search (data lock: 28 April 2020). Publications were screened to identify studies reporting non-haemorrhagic adverse events with flurbiprofen 8.75 mg and/or non-haemorrhagic adverse events in the comparator arm. Data extraction was performed for eligible studies according to pre-defined criteria and summarised in narratives, tables and figures. Risk of bias and certainty of evidence assessments were planned for each included study where results relating to the primary objective of the systematic review were available. Results: Of 1,528 publications identified by systematic literature searches, 26 met the inclusion criteria and were included in this review. None of these 26 studies contained information on non-haemorrhagic adverse events occurring as a result of a drug-drug interaction (interaction with concomitant medication used with flurbiprofen 8.75 mg), as per the primary objective and secondary objectives of the systematic review. Conclusion: Results from this systematic review on the risk of non-haemorrhagic events did not provide evidence for these events occurring as a result of interaction with other medicinal products. Additional appropriately designed studies would be required to confirm whether these findings suggest a true absence of risk or limitations in reporting.

20.
Acta Diabetol ; 61(6): 791-805, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38483572

RESUMO

AIM: This study was undertaken to explicate the shared and distinctive genetic susceptibility and immune dysfunction in patients with T1D alone and T1D with CD (T1D + CD). METHODS: A total of 100 T1D, 50 T1D + CD and 150 healthy controls were recruited. HLA-DRB1/DQB1 alleles were determined by PCR-sequence-specific primer method, SNP genotyping for CTLA-4 and PTPN22 was done by simple probe-based SNP-array and genotyping for INS-23 Hph1 A/T was done by RFLP. Autoantibodies and cytokine estimation was done by ELISA. Immune-regulation was analysed by flow-cytometry. Clustering of autoantigen epitopes was done by epitope cluster analytical tool. RESULTS: Both T1D alone and T1D + CD had a shared association of DRB1*03:01, DRB1*04, DRB3*01:07/15 and DQB1*02. DRB3*01:07/15 confers the highest risk for T1D with relative risk of 11.32 (5.74-22.31). Non-HLA gene polymorphisms PTPN22 and INS could discriminate between T1D and T1D + CD. T1D + CD have significantly higher titers of autoantibodies, expression of costimulatory molecules on CD4 and CD8 cells, and cytokine IL-17A and TGF-ß1 levels compared to T1D patients. Epitopes from immunodominant regions of autoantigens of T1D and CD clustered together with 40% homology. CONCLUSION: Same HLA genes provide susceptibility for both T1D and CD. Non-HLA genes CTLA4, PTPN22 and INS provide further susceptibility while different polymorphisms in PTPN22 and INS can discriminate between T1D and T1D + CD. Epitope homology between autoantigens of two diseases further encourages the two diseases to occur together. The T1D + CD being more common in females along with co-existence of thyroid autoimmunity, and have more immune dysregulated state than T1D alone.


Assuntos
Autoantígenos , Doença Celíaca , Diabetes Mellitus Tipo 1 , Predisposição Genética para Doença , Proteína Tirosina Fosfatase não Receptora Tipo 22 , Humanos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Índia/epidemiologia , Doença Celíaca/genética , Doença Celíaca/imunologia , Feminino , Masculino , Autoantígenos/imunologia , Autoantígenos/genética , Criança , Adolescente , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Adulto , Cadeias beta de HLA-DQ/genética , Autoanticorpos/imunologia , Autoanticorpos/sangue , Cadeias HLA-DRB1/genética , Adulto Jovem , Polimorfismo de Nucleotídeo Único , Pré-Escolar , Antígeno CTLA-4/genética , Genótipo , Estudos de Casos e Controles
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