Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Mod Pathol ; 29(6): 570-81, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26965583

RESUMO

A predominantly diffuse growth pattern and CD23 co-expression are uncommon findings in nodal follicular lymphoma and can create diagnostic challenges. A single case series in 2009 (Katzenberger et al) proposed a unique morphologic variant of nodal follicular lymphoma, characterized by a predominantly diffuse architecture, lack of the t(14;18) IGH/BCL2 translocation, presence of 1p36 deletion, frequent inguinal lymph node involvement, CD23 co-expression, and low clinical stage. Other studies on CD23+ follicular lymphoma, while associating inguinal location, have not specifically described this architecture. In addition, no follow-up studies have correlated the histopathologic and cytogenetic/molecular features of these cases, and they remain a diagnostic problem. We identified 11 cases of diffuse, CD23+ follicular lymphoma with histopathologic features similar to those described by Katzenberger et al. Along with pertinent clinical information, we detail their histopathology, IGH/BCL2 translocation status, lymphoma-associated chromosomal gains/losses, and assessment of mutations in 220 lymphoma-associated genes by massively parallel sequencing. All cases showed a diffuse growth pattern around well- to ill-defined residual germinal centers, uniform CD23 expression, mixed centrocytic/centroblastic cytology, and expression of at least one germinal center marker. Ten of 11 involved inguinal lymph nodes, 5 solely. By fluorescence in situ hybridization analysis, the vast majority lacked IGH/BCL2 translocation (9/11). Deletion of 1p36 was observed in five cases and included TNFRSF14. Of the six cases lacking 1p36 deletion, TNFRSF14 mutations were identified in three, highlighting the strong association of 1p36/TNFRSF14 abnormalities with this follicular lymphoma variant. In addition, 9 of the 11 cases tested (82%) had STAT6 mutations and nuclear P-STAT6 expression was detectable in the mutated cases by immunohistochemistry. The proportion of STAT6 mutations is higher than recently reported in conventional follicular lymphoma (11%). These findings lend support for a clinicopathologic variant of t(14;18) negative nodal follicular lymphoma and suggests importance of the interleukin (IL)-4/JAK/STAT6 pathway in this variant.


Assuntos
Biomarcadores Tumorais/genética , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 18 , Linfoma Folicular/genética , Mutação , Receptores de IgE/análise , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Fator de Transcrição STAT6/genética , Translocação Genética , Adulto , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Deleção Cromossômica , Transtornos Cromossômicos/imunologia , Transtornos Cromossômicos/patologia , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 1/imunologia , Análise Mutacional de DNA/métodos , Feminino , Genes de Cadeia Pesada de Imunoglobulina , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Linfoma Folicular/química , Linfoma Folicular/imunologia , Linfoma Folicular/patologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fator de Transcrição STAT6/análise
2.
BMC Genomics ; 16: 676, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26335021

RESUMO

BACKGROUND: The metastasis-associated lung adenocarcinoma transcription 1 (Malat1) is a highly conserved long non-coding RNA (lncRNA) gene. Previous studies showed that Malat1 is abundantly expressed in many tissues and involves in promoting tumor growth and metastasis by modulating gene expression and target protein activities. However, little is known about the biological function and regulation mechanism of Malat1 in normal cell proliferation. RESULTS: In this study we conformed that Malat1 is highly conserved across vast evolutionary distances amongst 20 species of mammals in terms of sequence, and found that mouse Malat1 expresses in tissues of liver, kidney, lung, heart, testis, spleen and brain, but not in skeletal muscle. After treating erythroid myeloid lymphoid (EML) cells with All-trans Retinoic Acid (ATRA), we investigated the expression and regulation of Malat1 during hematopoietic differentiation, the results showed that ATRA significantly down regulates Malat1 expression during the differentiation of EML cells. Mouse LRH (Lin-Rhodamine(low) Hoechst(low)) cells that represent the early-stage progenitor cells show a high level of Malat1 expression, while LRB (Lin - Hoechst(Low) Rhodamine(Bright)) cells that represent the late-stage progenitor cells had no detectable expression of Malat1. Knockdown experiment showed that depletion of Malat1 inhibits the EML cell proliferation. Along with the down regulation of Malat1, the tumor suppressor gene p53 was up regulated during the differentiation. Interestingly, we found two p53 binding motifs with help of bioinformatic tools, and the following chromatin immunoprecipitation (ChIP) test conformed that p53 acts as a transcription repressor that binds to Malat1's promoter. Furthermore, we testified that p53 over expression in EML cells causes down regulation of Malat1. CONCLUSIONS: In summary, this study indicates Malat1 plays a critical role in maintaining the proliferation potential of early-stage hematopoietic cells. In addition to its biological function, the study also uncovers the regulation pattern of Malat1 expression mediated by p53 in hematopoietic differentiation. Our research shed a light on exploring the Malat1 biological role including therapeutic significance to inhibit the proliferation potential of malignant cells.


Assuntos
Diferenciação Celular , Sequência Conservada/genética , Evolução Molecular , Hematopoese , RNA Longo não Codificante/genética , Animais , Medula Óssea/efeitos dos fármacos , Medula Óssea/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células , Regulação para Baixo/genética , Hematopoese/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Camundongos Endogâmicos BALB C , Primatas , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , RNA Longo não Codificante/metabolismo , Especificidade da Espécie , Transcrição Gênica/efeitos dos fármacos , Tretinoína/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima/efeitos dos fármacos
3.
J Urol ; 193(5): 1479-85, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25498568

RESUMO

PURPOSE: Accurate discrimination of benign oncocytoma and malignant renal cell carcinoma is useful for planning appropriate treatment strategies for patients with renal masses. Classification of renal neoplasms solely based on histopathology can be challenging, especially the distinction between chromophobe renal cell carcinoma and oncocytoma. In this study we develop and validate an algorithm based on genomic alterations for the classification of common renal neoplasms. MATERIALS AND METHODS: Using TCGA renal cell carcinoma copy number profiles and the published literature, a classification algorithm was developed and scoring criteria were established for the presence of each genomic marker. As validation, 191 surgically resected formalin fixed paraffin embedded renal neoplasms were blindly submitted to targeted array comparative genomic hybridization and classified according to the algorithm. CCND1 rearrangement was assessed by fluorescence in situ hybridization. RESULTS: The optimal classification algorithm comprised 15 genomic markers, and involved loss of VHL, 3p21 and 8p, and chromosomes 1, 2, 6, 10 and 17, and gain of 5qter, 16p, 17q and 20q, and chromosomes 3, 7 and 12. On histological rereview (leading to the exclusion of 3 specimens) and using histology as the gold standard, 58 of 62 (93%) clear cell, 51 of 56 (91%) papillary and 33 of 34 (97%) chromophobe renal cell carcinomas were classified correctly. Of the 36 oncocytoma specimens 33 were classified as oncocytoma (17 by array comparative genomic hybridization and 10 by array comparative genomic hybridization plus fluorescence in situ hybridization) or benign (6). Overall 93% diagnostic sensitivity and 97% specificity were achieved. CONCLUSIONS: In a clinical diagnostic setting the implementation of genome based molecular classification could serve as an ancillary assay to assist in the histological classification of common renal neoplasms.


Assuntos
Adenoma Oxífilo/classificação , Adenoma Oxífilo/genética , Algoritmos , Carcinoma de Células Renais/classificação , Carcinoma de Células Renais/genética , Genômica , Córtex Renal , Neoplasias Renais/classificação , Neoplasias Renais/genética , Hibridização Genômica Comparativa , Humanos , Hibridização in Situ Fluorescente
4.
Appl Microbiol Biotechnol ; 98(8): 3669-78, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24146077

RESUMO

Plasmodium falciparum is the causative agent of the most serious form of malaria. Although a combination of control measures has significantly limited malaria morbidity and mortality in the last few years, it is generally agreed that sustained control or even eradication will require additional tools including an effective malaria vaccine. Merozoite surface protein 4, MSP4, which is present during the asexual stage of P. falciparum, is a recognized target that would be useful in a subunit vaccine against blood stages of malaria. Falciparum malaria is most prevalent in developing countries, and this in turn leads to a requirement for safe, low-cost vaccines. We have attempted to utilize the nonpathogenic, gram-positive organism Bacillus subtilis to produce PfMSP4. PfMSP4 was secreted into the culture medium at a yield of 4.5 mg/L. Characterization studies including SDS-PAGE, mass spectrometry, and N-terminal sequencing indicated that the B. subtilis expression system secreted a full length PfMSP4 protein compared to a truncated version in Escherichia coli. Equivalent amounts of purified B. subtilis and E. coli-derived PfMSP4 were used for immunization studies, resulting in statistically significant higher mean titer values for the B. subtilis-derived immunogen. The mouse antibodies raised against B. subtilis produced PfMSP4 that were reactive to parasite proteins as evidenced by immunoblotting on parasite lysate and indirect immunofluorescence assays of fixed parasites. The B. subtilis expression system, in contrast to E. coli, expresses higher amounts of full length PfMSP4 products, decreased levels of aggregates, and allows the development of simplified downstream processing procedures.


Assuntos
Antígenos de Protozoários/imunologia , Antígenos de Protozoários/isolamento & purificação , Bacillus subtilis/genética , Vacinas Antimaláricas/imunologia , Vacinas Antimaláricas/isolamento & purificação , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/isolamento & purificação , Animais , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/química , Antígenos de Protozoários/genética , Eletroforese em Gel de Poliacrilamida , Imunofluorescência , Immunoblotting , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/genética , Espectrometria de Massas , Camundongos , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Análise de Sequência de Proteína , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/isolamento & purificação
5.
Proc Natl Acad Sci U S A ; 108(10): 3982-7, 2011 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-21368137

RESUMO

Microtubules are integral to neuronal development and function. They endow cells with polarity, shape, and structure, and their extensive surface area provides substrates for intracellular trafficking and scaffolds for signaling molecules. Consequently, microtubule polymerization dynamics affect not only structural features of the cell but also the subcellular localization of proteins that can trigger intracellular signaling events. In the nematode Caenorhabditis elegans, the processes of touch receptor neurons are filled with a bundle of specialized large-diameter microtubules. We find that conditions that disrupt these microtubules (loss of either the MEC-7 ß-tubulin or MEC-12 α-tubulin or growth in 1 mM colchicine) cause a general reduction in touch receptor neuron (TRN) protein levels. This reduction requires a p38 MAPK pathway (DLK-1, MKK-4, and PMK-3) and the transcription factor CEBP-1. Cells may use this feedback pathway that couples microtubule state and MAPK activation to regulate cellular functions.


Assuntos
Caenorhabditis elegans/metabolismo , Expressão Gênica , Microtúbulos/metabolismo , Neurônios/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Colchicina/farmacologia , Mutação , Neurônios/efeitos dos fármacos , Neurônios/enzimologia
6.
Radiol Case Rep ; 19(3): 1035-1039, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38226045

RESUMO

The authors report a case of pathologically proven intracardiac bronchogenic cyst embedded within the interatrial septum of a 30-year-old woman presenting with chest pain and first-degree AV block. Multimodality imaging played an essential role in the discovery, investigation, and diagnosis of this extremely rare entity.

7.
Nat Methods ; 7(5): 407-11, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20364149

RESUMO

We describe a method for conditional regulation of gene expression based on the processing of an intron cassette. The RNA processing factor MEC-8 is necessary for the function of the Caenorhabditis elegans touch receptor neurons; mec-8 mutants are touch insensitive. We show here that this insensitivity involves the loss of MEC-8-dependent splicing of mec-2, which encodes a component of the mechanosensory transduction complex. MEC-8 is needed to remove the ninth intron in mec-2 pre-mRNA to form the longest of three mRNAs, mec-2a. Without MEC-8, splicing causes the termination of the transcript. Inclusion of mec-2 intron 9 is sufficient to convey mec-8-dependent regulation on other genes and, in mec-8(u218ts) mutants, resulted in their temperature-dependent expression. Because mec-8 is expressed ubiquitously in embryos and extensively in larvae, this system should produce temperature-sensitive expression for most genes. As an example, we report a strain that exhibits temperature-dependent RNA interference.


Assuntos
Proteínas de Caenorhabditis elegans/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Interferência de RNA/fisiologia , Splicing de RNA/fisiologia , Proteínas de Ligação a RNA/fisiologia , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Genes de Helmintos , Íntrons/fisiologia , Proteínas de Membrana/genética , Temperatura
8.
Appl Microbiol Biotechnol ; 94(1): 151-61, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22170105

RESUMO

Development of a safe, effective and affordable malaria vaccine is central to global disease control efforts. One of the most highly regarded proteins for inclusion in an asexual blood stage subunit vaccine is the 19-kDa C-terminal fragment of merozoite surface protein 1 (MSP1(19)). As production of vaccine antigens in plants can potentially overcome cost and delivery hurdles, we set out to produce MSP1(19) in plants, characterise the protein and test its immunogenicity using a mouse model. Plasmodium yoelii MSP1(19) (PyMSP1(19)) was produced in Nicotiana benthamiana using the MagnICON® deconstructed TMV-based viral vector. PyMSP1(19) yield of at least 23% total soluble protein (TSP;3-4 mg/g Fwt) were achieved using a codon-optimised construct that was targeted to the apoplast. Freeze-dried leaf powder contained at least 20 mg PyMSP1(19) per gram dry weight and the protein retained immunogenicity in this form for more than 2 years. Characterisation studies, including SDS-PAGE, mass spectrometry and circular dichroism, indicated that the plant-expressed PyMSP1(19) was similar to its Escherichia coli- and Saccharomyces cerevisiae-expressed counterparts. Purified plant-made PyMSP1(19) induced strong immune responses following intraperitoneal immunisation, although titres were lower than those induced by an equivalent dose of purified E. coli-expressed PyMSP1(19). The reason for this is uncertain but may be due to differences in the oligomerisation profile of the vaccines. The plant-made PyMSP1(19) vaccine was also found to be orally immunogenic when delivered alone or following immunisation with a PyMSP1(19) DNA vaccine. This study adds to an increasing body of research supporting the feasibility of plants as both a factory for the production of malaria antigens, and as a safe and affordable platform for oral delivery of a temperature-stable malaria vaccine.


Assuntos
Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Malária/imunologia , Proteína 1 de Superfície de Merozoito/genética , Proteína 1 de Superfície de Merozoito/imunologia , Nicotiana/genética , Plasmodium yoelii/imunologia , Motivos de Aminoácidos , Animais , Antígenos de Protozoários/química , Feminino , Expressão Gênica , Humanos , Imunização , Malária/parasitologia , Malária/prevenção & controle , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/química , Vacinas Antimaláricas/genética , Vacinas Antimaláricas/imunologia , Proteína 1 de Superfície de Merozoito/química , Camundongos , Camundongos Endogâmicos BALB C , Plasmodium yoelii/química , Plasmodium yoelii/genética , Plasmodium yoelii/crescimento & desenvolvimento , Nicotiana/metabolismo
9.
Langmuir ; 27(7): 3703-12, 2011 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-21361304

RESUMO

Low efficiency is often observed in the delivery of DNA vaccines. The use of superparamagnetic nanoparticles (SPIONs) to deliver genes via magnetofection could improve transfection efficiency and target the vector to its desired locality. Here, magnetofection was used to enhance the delivery of a malaria DNA vaccine encoding Plasmodium yoelii merozoite surface protein MSP1(19) (VR1020-PyMSP1(19)) that plays a critical role in Plasmodium immunity. The plasmid DNA (pDNA) containing membrane associated 19-kDa carboxyl-terminal fragment of merozoite surface protein 1 (PyMSP1(19)) was conjugated with superparamagnetic nanoparticles coated with polyethyleneimine (PEI) polymer, with different molar ratio of PEI nitrogen to DNA phosphate. We reported the effects of SPIONs-PEI complexation pH values on the properties of the resulting particles, including their ability to condense DNA and the gene expression in vitro. By initially lowering the pH value of SPIONs-PEI complexes to 2.0, the size of the complexes decreased since PEI contained a large number of amino groups that became increasingly protonated under acidic condition, with the electrostatic repulsion inducing less aggregation. Further reaggregation was prevented when the pHs of the complexes were increased to 4.0 and 7.0, respectively, before DNA addition. SPIONs/PEI complexes at pH 4.0 showed better binding capability with PyMSP1(19) gene-containing pDNA than those at neutral pH, despite the negligible differences in the size and surface charge of the complexes. This study indicated that the ability to protect DNA molecules due to the structure of the polymer at acidic pH could help improve the transfection efficiency. The transfection efficiency of magnetic nanoparticle as carrier for malaria DNA vaccine in vitro into eukaryotic cells, as indicated via PyMSP1(19) expression, was significantly enhanced under the application of external magnetic field, while the cytotoxicity was comparable to the benchmark nonviral reagent (Lipofectamine 2000).


Assuntos
Vacinas Antimaláricas/química , Nanopartículas/química , Polietilenoimina/química , Vacinas de DNA/química , Animais , Células COS , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/efeitos adversos , Portadores de Fármacos/química , Vacinas Antimaláricas/administração & dosagem , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Nanopartículas/administração & dosagem , Nanopartículas/efeitos adversos , Nanopartículas/ultraestrutura , Nanotecnologia , Vacinas de DNA/administração & dosagem
10.
J Diet Suppl ; 18(6): 597-613, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33078636

RESUMO

INTRODUCTION: Supplementation with Rhodiola Rosea (RR) and Cordyceps Sinensis (CS) has been shown to improve aerobic performance, but their influence on concurrent training (resistance training plus high intensity interval training) outcomes has not been established. The purpose of this study was to determine the effects of supplementation with a multi-ingredient performance supplement (MIPS) containing RR and CS during a 14-week training and testing program on body composition, weekly exercise training outcomes, overall training and performance outcomes, and hormone profiles. METHODS: Active college-aged men (N = 21) were stratified into either a MIPS or a placebo (PLA) group. Both groups completed 14 weeks of training and testing. Body composition, overall training outcomes, and blood sample collection occurred at weeks 0, 7, and 14, while training performance was evaluated weekly. RESULTS: Both groups improved (p < 0.05) percent body fat (-1.3%), bench press (+4%) and squat strength (+8%), with no difference between groups. Serum cortisol concentrations significantly decreased (-11%) but there were no differences between groups. No other changes in blood hormone profiles occurred. Weekly exercise performance data suggests that MIPS improved sprint performance, bench press lifting volume, and total workload, but this did not lead to improved overall training performance compared to PLA over the14-week study. CONCLUSION: Despite MIPS improving certain aspects of weekly training performance, supplementation with MIPS for 14 weeks did not improve body composition, overall training and performance outcomes, or blood biomarkers of health in response to concurrent training in young men compared to PLA. This study was registered with clinicaltrials. gov (NCT02383017).


Assuntos
Cordyceps , Treinamento Resistido , Rhodiola , Composição Corporal , Suplementos Nutricionais , Humanos , Força Muscular , Adulto Jovem
11.
PLoS One ; 16(4): e0243683, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909614

RESUMO

Identification of genomic mutations by molecular testing plays an important role in diagnosis, prognosis, and treatment of myeloid neoplasms. Next-generation sequencing (NGS) is an efficient method for simultaneous detection of clinically significant genomic mutations with high sensitivity. Various NGS based in-house developed and commercial myeloid neoplasm panels have been integrated into routine clinical practice. However, some genes frequently mutated in myeloid malignancies are particularly difficult to sequence with NGS panels (e.g., CEBPA, CARL, and FLT3). We report development and validation of a 48-gene NGS panel that includes genes that are technically challenging for molecular profiling of myeloid neoplasms including acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and myeloproliferative neoplasms (MPN). Target regions were captured by hybridization with complementary biotinylated DNA baits, and NGS was performed on an Illumina NextSeq500 instrument. A bioinformatics pipeline that was developed in-house was used to detect single nucleotide variations (SNVs), insertions/deletions (indels), and FLT3 internal tandem duplications (FLT3-ITD). An analytical validation study was performed on 184 unique specimens for variants with allele frequencies ≥5%. Variants identified by the 48-gene panel were compared to those identified by a 35-gene hematologic neoplasms panel using an additional 137 unique specimens. The developed assay was applied to a large cohort (n = 2,053) of patients with suspected myeloid neoplasms. Analytical validation yielded 99.6% sensitivity (95% CI: 98.9-99.9%) and 100% specificity (95% CI: 100%). Concordance of variants detected by the 2 tested panels was 100%. Among patients with suspected myeloid neoplasms (n = 2,053), 54.5% patients harbored at least one clinically significant mutation: 77% in AML patients, 48% in MDS, and 45% in MPN. Together, these findings demonstrate that the assay can identify mutations associated with diagnosis, prognosis, and treatment options of myeloid neoplasms even in technically challenging genes.


Assuntos
Neoplasias Hematológicas , Sequenciamento de Nucleotídeos em Larga Escala , Leucemia Mieloide Aguda , Mutação , Síndromes Mielodisplásicas , Proteínas de Neoplasias , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo
12.
Infect Immun ; 78(2): 680-7, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19917716

RESUMO

The absence of a validated surrogate marker for the immune state has complicated the design of a subunit vaccine against asexual stages of Plasmodium falciparum. In particular, it is not known whether the capacity to induce antibodies that inhibit parasite growth in vitro is an important criterion for selection of P. falciparum proteins to be assessed in human vaccine trials. We examined this issue in the Plasmodium yoelii rodent malaria model using the 19-kDa C-terminal fragment of merozoite surface protein 1 (MSP1(19)). To examine the relationship between inhibitory antibodies in immunized mice and the immune state, as indicated by resistance to a blood-stage challenge, we used an allelic replacement strategy to generate a transgenic P. falciparum line that expresses MSP1(19) from P. yoelii. We show that MSP1(19) is functionally conserved across these two divergent Plasmodium species, and replacing PfMSP1(19) with PyMSP1(19) has no detectable effect on parasite growth in vitro. By comparing growth rates of this transgenic line with a matched transgenic line that expresses the endogenous PfMSP1(19), we developed an assay to measure the specific growth-inhibitory activity directed exclusively to the PyMSP1(19) protein in the sera from vaccinated animals. To validate this assay, sera from rabbits immunized with recombinant PyMSP1(19) were tested and showed specific inhibitory activity in a concentration-dependent manner. In mice that were immunized with recombinant PyMSP1(19), the levels of PyMSP1(19)-specific inhibitory activity did not correlate with the total antibody levels measured by enzyme-linked immunosorbent assay. Furthermore, they did not correlate with resistance to subsequent blood-stage infection, and some mice with complete protection showed no detectable inhibitory activity in their prechallenge sera. These data indicated that growth-inhibitory activity measured in vitro was not a reliable predictor of immune status in vivo, and the reliance on this criterion to select vaccine candidates for human clinical trials may be misplaced. The transgenic lines further offer useful tools for comparing the efficacy of MSP1(19)-based vaccines that utilize different immunization regimens and antigen formulations.


Assuntos
Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Proteína 1 de Superfície de Merozoito/imunologia , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Malária Falciparum/prevenção & controle , Camundongos , Plasmodium falciparum/imunologia , Plasmodium yoelii/imunologia , Coelhos
13.
Malar J ; 9: 348, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21122144

RESUMO

BACKGROUND: Parasitaemia, the percentage of infected erythrocytes, is used to measure progress of experimental Plasmodium infection in infected hosts. The most widely used technique for parasitaemia determination is manual microscopic enumeration of Giemsa-stained blood films. This process is onerous, time consuming and relies on the expertise of the experimenter giving rise to person-to-person variability. Here the development of image-analysis software, named Plasmodium AutoCount, which can automatically generate parasitaemia values from Plasmodium-infected blood smears, is reported. METHODS: Giemsa-stained blood smear images were captured with a camera attached to a microscope and analysed using a programme written in the Python programming language. The programme design involved foreground detection, cell and infection detection, and spurious hit filtering. A number of parameters were adjusted by a calibration process using a set of representative images. Another programme, Counting Aid, written in Visual Basic, was developed to aid manual counting when the quality of blood smear preparation is too poor for use with the automated programme. RESULTS: This programme has been validated for use in estimation of parasitemia in mouse infection by Plasmodium yoelii and used to monitor parasitaemia on a daily basis for an entire challenge infection. The parasitaemia values determined by Plasmodium AutoCount were shown to be highly correlated with the results obtained by manual counting, and the discrepancy between automated and manual counting results were comparable to those found among manual counts of different experimenters. CONCLUSIONS: Plasmodium AutoCount has proven to be a useful tool for rapid and accurate determination of parasitaemia from infected mouse blood. For greater accuracy when smear quality is poor, Plasmodium AutoCount, can be used in conjunction with Counting Aid.


Assuntos
Automação/métodos , Sangue/parasitologia , Malária/veterinária , Parasitemia/veterinária , Parasitologia/métodos , Plasmodium yoelii/isolamento & purificação , Animais , Processamento de Imagem Assistida por Computador/métodos , Malária/diagnóstico , Camundongos , Microscopia/métodos , Parasitemia/diagnóstico
14.
Vaccines (Basel) ; 8(4)2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33153189

RESUMO

Vaccines against blood-stage malaria often aim to induce antibodies to neutralize parasite entry into red blood cells, interferon gamma (IFNγ) produced by T helper 1 (Th1) CD4+ T cells or interleukin 4 (IL-4) produced by T helper 2 (Th2) cells to provide B cell help. One vaccine delivery method for suitable putative malaria protein antigens is the use of nanoparticles as vaccine carriers. It has been previously shown that antigen conjugated to inorganic nanoparticles in the viral-particle size range (~40-60 nm) can induce protective antibodies and T cells against malaria antigens in a rodent malaria challenge model. Herein, it is shown that biodegradable pullulan-coated iron oxide nanoparticles (pIONPs) can be synthesized in this same size range. The pIONPs are non-toxic and do not induce conventional pro-inflammatory cytokines in vitro and in vivo. We show that murine blood-stage antigen MSP4/5 from Plasmodium yoelii could be chemically conjugated to pIONPs and the use of these conjugates as immunogens led to the induction of both specific antibodies and IFNγ CD4+ T cells reactive to MSP4/5 in mice, comparable to responses to MSP4/5 mixed with classical adjuvants (e.g., CpG or Alum) that preferentially induce Th1 or Th2 cells individually. These results suggest that biodegradable pIONPs warrant further exploration as carriers for developing blood-stage malaria vaccines.

15.
Plant Biotechnol J ; 7(9): 846-55, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19781007

RESUMO

Increasing numbers of plant-made vaccines and pharmaceuticals are entering the late stage of product development and commercialization. Despite the theoretical benefits of such production, expression of parasite antigens in plants, particularly those from Plasmodium, the causative parasites for malaria, have achieved only limited success. We have previously shown that stable transformation of tobacco plants with a plant-codon optimized form of the Plasmodium yoelii merozoite surface protein 4/5 (PyMSP4/5) gene resulted in PyMSP4/5 expression of up to approximately 0.25% of total soluble protein. In this report, we describe the rapid expression of PyMSP4/5 in Nicotiana benthamiana leaves using the deconstructed tobacco mosaic virus-based magnICON expression system. PyMSP4/5 yields of up to 10% TSP or 1-2 mg/g of fresh weight were consistently achieved. Characterization of the recombinant plant-made PyMSP4/5 indicates that it is structurally similar to PyMSP4/5 expressed by Escherichia coli. It is notable that the plant-made PyMSP4/5 protein retained its immunogenicity following long-term storage at ambient temperature within freeze-dried leaves. With assistance from a mucosal adjuvant the PyMSP4/5-containing leaves induced PyMSP4/5-specific antibodies when delivered orally to naïve mice or mice primed by a DNA vaccine. This study provides evidence that immunogenic Plasmodium antigens can be produced in large quantities in plants using the magnICON viral vector system.


Assuntos
Antígenos de Protozoários/biossíntese , Vacinas Antimaláricas/imunologia , Proteínas de Membrana/biossíntese , Nicotiana/metabolismo , Proteínas de Protozoários/biossíntese , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Feminino , Vetores Genéticos , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plasmodium/genética , Proteínas de Protozoários/imunologia , Nicotiana/genética , Vírus do Mosaico do Tabaco/genética , Vacinas de DNA/imunologia
16.
Front Immunol ; 10: 331, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30930890

RESUMO

Malaria remains a significant health problem in many tropical and sub-tropical regions. The development of vaccines against the clinically active blood-stage of infection needs to consider variability and polymorphism in target antigens, and an adjuvant system able to induce broad spectrum immunity comprising both antibodies and helper T cells. Moreover, recent studies have shown some conventional pro-inflammatory adjuvants can also promote expansion of immunosuppressive regulatory T cells (Treg) and myeloid derived suppressor cells (MDSC), both of which could negatively impact malaria disease progression. Herein, we explore the ability of a model nanoparticle delivery system (polystyrene nanoparticles; PSNPs), previously proven to not induce conventional inflammation, Treg or MDSC, to induce immunity to MSP4/5 from Plasmodium yoelii, a member of the MSP4 and MSP5 family of proteins which are highly conserved across diverse malaria species including P. falciparum. The results show PSNPs-MSP4/5 conjugates are highly immunogenic, inducing immune responses comprising both T helper 1 (Th1) and Th2 cellular immunity, and a spectrum of antibody subclasses including IgG1, IgG2a, and IgG2b. Benchmarked against Alum and Complete Freund's Adjuvant (CFA), the immune responses that were induced were of comparable or higher magnitude, for both T cell frequencies by ELISpot and antibody responses in terms of ELISA end titer. Importantly, immunization with PSNPs-MSP4/5 induced partial protection against malaria blood-stage infection (50-80%) shown to be mechanistically dependent on interferon gamma (IFN-γ) production. These results expand the scope of adjuvants considered for malaria blood-stage vaccine development to those that do not use conventional adjuvant pathways and emphasizes the critical role of cellular immunity and specifically IFN-γ producing cells in providing moderate protection against blood-stage malaria comparable to Freunds adjuvant.


Assuntos
Antígenos de Protozoários/imunologia , Vacinas Antimaláricas/imunologia , Malária Falciparum/imunologia , Proteínas de Membrana/imunologia , Nanopartículas/administração & dosagem , Proteínas de Protozoários/imunologia , Vacinas Sintéticas/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antiprotozoários/imunologia , Formação de Anticorpos/imunologia , Imunização/métodos , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Células Th1/imunologia , Células Th2/imunologia
18.
Oncotarget ; 8(3): 4062-4078, 2017 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-27845897

RESUMO

The Polycomb repressive complex 2 (PRC2), which contains three core proteins EZH2, EED and SUZ12, controls chromatin compaction and transcription repression through trimethylation of lysine 27 on histone 3. The (7;17)(p15;q21) chromosomal translocation present in most cases of endometrial stromal sarcomas (ESSs) results in the in-frame fusion of the JAZF1 and SUZ12 genes. We have investigated whether and how the fusion protein JAZF1-SUZ12 functionally alters PRC2. We found that the fusion protein exists at high levels in ESS containing the t(7;17). Co-transient transfection assay indicated JAZF1-SUZ12 destabilized PRC2 components EZH2 and EED, resulting in decreased histone methyl transferase (HMT) activity, which was confirmed by in vitro studies using reconstituted PRC2 and nucleosome array substrates. We also demonstrated the PRC2 containing the fusion protein decreased the binding affinity to target chromatin loci. In addition, we found that trimethylation of H3K27 was decreased in ESS samples with the t(7;17), but there was no detectable change in H3K9 in these tissues. Moreover, re-expression of SUZ12 in Suz12 (-/-) ES cells rescued the neuronal differentiation while the fusion protein failed to restore this function and enhanced cell proliferation. In summary, our studies reveal that JAZF1-SUZ12 fusion protein disrupts the PRC2 complex, abolishes HMT activity and subsequently activates chromatin/genes normally repressed by PRC2. Such dyesfunction of PRC2 inhibits normal neural differentiation of ES cell and increases cell proliferation. Related changes induced by the JAZF-SUZ12 protein in endometrial stromal cells may explain the oncogenic effect of the t(7;17) in ESS.


Assuntos
Cromatina/genética , Neoplasias do Endométrio/genética , Proteínas de Neoplasias/genética , Complexo Repressor Polycomb 2/metabolismo , Proteínas Recombinantes de Fusão/genética , Animais , Diferenciação Celular , Linhagem Celular , Montagem e Desmontagem da Cromatina , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 7/genética , Proteínas Correpressoras , Proteínas de Ligação a DNA , Repressão Epigenética , Feminino , Células HEK293 , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/genética , Humanos , Metilação , Camundongos , Complexo Repressor Polycomb 2/genética , Fatores de Transcrição , Translocação Genética
19.
Nanomaterials (Basel) ; 7(2)2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-28336871

RESUMO

DNA vaccines offer cost, flexibility, and stability advantages, but administered alone have limited immunogenicity. Previously, we identified optimal configurations of magnetic vectors comprising superparamagnetic iron oxide nanoparticles (SPIONs), polyethylenimine (PEI), and hyaluronic acid (HA) to deliver malaria DNA encoding Plasmodium yoelii (Py) merozoite surface protein MSP119 (SPIONs/PEI/DNA + HA gene complex) to dendritic cells and transfect them with high efficiency in vitro. Herein, we evaluate their immunogenicity in vivo by administering these potential vaccine complexes into BALB/c mice. The complexes induced antibodies against PyMSP119, with higher responses induced intraperitoneally than intramuscularly, and antibody levels further enhanced by applying an external magnetic field. The predominant IgG subclasses induced were IgG2a followed by IgG1 and IgG2b. The complexes further elicited high levels of interferon gamma (IFN-γ), and moderate levels of interleukin (IL)-4 and IL-17 antigen-specific splenocytes, indicating induction of T helper 1 (Th1), Th2, and Th17 cell mediated immunity. The ability of such DNA/nanoparticle complexes to induce cytophilic antibodies together with broad spectrum cellular immunity may benefit malaria vaccines.

20.
Leuk Lymphoma ; 57(4): 899-908, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26294112

RESUMO

Genomic copy number alterations (CNAs) in diffuse large B-cell lymphoma (DLBCL) have roles in disease pathogenesis, but overall clinical relevance remains unclear. Herein, an unbiased algorithm was uniformly applied across three genome profiling datasets comprising 392 newly-diagnosed DLBCL specimens that defined 32 overlapping CNAs, involving 36 minimal common regions (MCRs). Scoring criteria were established for 50 aberrations within the MCRs while considering peak gains/losses. Application of these criteria to independent datasets revealed novel candidate genes with coordinated expression, such as CNOT2, potentially with pathogenic roles. No one single aberration significantly associated with patient outcome across datasets, but genomic complexity, defined by imbalance in more than one MCR, significantly portended adverse outcome in two of three independent datasets. Thus, the standardized scoring of CNAs currently developed can be uniformly applied across platforms, affording robust validation of genomic imbalance and complexity in DLBCL and overall clinical utility as biomarkers of patient outcome.


Assuntos
Variação Genética , Genômica , Linfoma Difuso de Grandes Células B/genética , Locos de Características Quantitativas , Anticorpos Monoclonais Murinos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Aberrações Cromossômicas , Hibridização Genômica Comparativa , Ciclofosfamida/uso terapêutico , Variações do Número de Cópias de DNA , Doxorrubicina/uso terapêutico , Feminino , Regulação Neoplásica da Expressão Gênica , Testes Genéticos , Genômica/métodos , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único , Prednisona/uso terapêutico , Prognóstico , Rituximab , Transdução de Sinais , Transcriptoma , Vincristina/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA