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1.
Heliyon ; 10(8): e29455, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38644827

RESUMO

Licorice processing waste was pyrolyzed at different temperatures (500 and 700 °C) to obtain biochar (BC500 and BC700) for use as a slow-release fertilizer on Solanum lycopersicum. The materials were characterized through BET analysis, SEM, elemental analysis, pHzc, and pyrolysis temperature effect was evaluated. The biochars were functionalized by the impregnation method to enrich them with nitrogen, phosphorus, and potassium (NPK), and desorption tests were performed in aqueous solution at different pHs (5 and 7). The pseudo-second-order model described well the release of all 3 macronutrients tested, BC500 was found to have slower release kinetics due to smaller pore size, reaching adsorption/desorption equilibrium after 14 days, compared with 10 for BC700, Kdes were lower in all 3 cases and NPK content was higher, initial pH did not change the release kinetics. BC500 was selected as an agricultural soil conditioner by testing at both different dosages of BC (0-25 %) and different NPK ratios (3:1:4 and 4:1:3). The treatment significance was evaluated. The best treatment resulted in BC dosage of 25 % nutrient ratio 4:1:3 which increased, compared to the control, total chlorophyll content (+38 %) and carotenoids (+15 %).

2.
Nanomaterials (Basel) ; 14(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38334564

RESUMO

Iron-doped titanium dioxide nanoparticles are widely employed for photocatalytic applications under visible light due to their promising performance. Nevertheless, the manufacturing process, the role of Fe3+ ions within the crystal lattice of titanium dioxide, and their impact on operational parameters are still a subject of controversy. Based on these assumptions, the primary objective of this review is to delineate the role of iron, ascertain the optimal quantity, and elucidate its influence on the main photocatalysis parameters, including nanoparticle size, band gap, surface area, anatase-rutile transition, and point of zero charge. Moreover, an optimized synthesis method based on comprehensive data and insights from the existing literature is proposed, focusing exclusively on iron-doped titanium oxide while excluding other dopant variants.

3.
Diagnostics (Basel) ; 12(10)2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36292100

RESUMO

Dilated cardiomyopathy (DCM) is a complex disease affecting young adults. It is a pathological condition impairing myocardium activity that leads to heart failure and, in the most severe cases, transplantation, which is currently the only possible therapy for the disease. DCM can be attributed to many genetic determinants interacting with environmental factors, resulting in a highly variable phenotype. Due to this complexity, the early identification of causative gene mutations is an important goal to provide a genetic diagnosis, implement pre-symptomatic interventions, and predict prognosis. The advent of next-generation sequencing (NGS) has opened a new path for mutation screening, and exome sequencing provides a promising approach for identifying causal variants in known genes and novel disease-associated candidates. We analyzed the whole-exome sequencing (WES) of 15 patients affected by DCM without overloading (hypertension, valvular, or congenital heart disease) or chronic ischemic conditions. We identified 70 pathogenic or likely pathogenic variants and 1240 variants of uncertain clinical significance. Gene ontology enrichment analysis was performed to assess the potential connections between affected genes and biological or molecular function, identifying genes directly related to extracellular matrix organization, transcellular movement through the solute carrier and ATP-binding cassette transporter, and vitamin B12 metabolism. We found variants in genes implicated to a different extent in cardiac function that may represent new players in the complex genetic scenario of DCM.

4.
J Med Virol ; 94(11): 5567-5573, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35831579

RESUMO

In December 2019, several patients were hospitalized and diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which subsequently led to a global pandemic. To date, there are no studies evaluating the relationship between the respiratory phageome and the SARS-CoV-2 infection. The current study investigated the phageome profiles in the nasopharyngeal swabs collected from 55 patients during the three different waves of coronavirus disease 2019 (COVID-19) in the Campania Region (Southern Italy). Data obtained from the taxonomic profiling show that phage families belonging to the order Caudovirales have a high abundance in the patient samples. Moreover, the severity of the COVID-19 infection seems to be correlated with the phage abundance.


Assuntos
COVID-19 , Humanos , Pandemias , SARS-CoV-2 , Índice de Gravidade de Doença , Viroma
5.
Ann Biomed Eng ; 49(9): 2243-2259, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33728867

RESUMO

Mechanobiology has nowadays acquired the status of a topic of fundamental importance in a degree in Biological Sciences. It is inherently a multidisciplinary topic where biology, physics and engineering competences are required. A course in mechanobiology should include lab experiences where students can appreciate how mechanical stimuli from outside affect living cell behaviour. Here we describe all the steps to build a cell stretcher inside an on-stage cell incubator. This device allows exposing living cells to a periodic mechanical stimulus similar to what happens in physiological conditions such as, for example, in the vascular system or in the lungs. The reaction of the cells to the periodic mechanical stretching represents a prototype of a mechanobiological signal integrated by living cells. We also provide the theoretical and experimental aspects related to the calibration of the stretcher apparatus at a level accessible to researchers not used to dealing with topics like continuum mechanics and analysis of deformations. We tested our device by stretching cells of two different lines, U87-MG and Balb-3T3 cells, and we analysed and discussed the effect of the periodic stimulus on both cell reorientation and migration. We also discuss the basic aspects related to the quantitative analysis of the reorientation process and of cell migration. We think that the device we propose can be easily reproduced at low-cost within a project-oriented course in the fields of biology, biotechnology and medical engineering.


Assuntos
Biofísica/métodos , Estresse Mecânico , Animais , Fenômenos Biomecânicos , Linhagem Celular , Movimento Celular , Humanos , Camundongos , Imagem com Lapso de Tempo
6.
J Mater Chem B ; 9(2): 392-403, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33283828

RESUMO

Proteins are widely explored as therapeutic agents, but some issues remain alive in their delivery versus target tissues and organs. Especially in the case of water-labile proteins, they undergo rapid failure if not properly stored or once they have encountered the biological environment. In this framework, delivery systems can be very useful to protect such proteins both during storage and during their administration. In particular, polymer microneedles (MNs) represent an interesting tool for the in vivo administration of proteins, avoiding the aggressive gastrointestinal or blood environment. Here, polymer microneedles for the encapsulation and delivery of the labile protein collagenase are presented. Polyvinylpyrrolidone-hyaluronic acid (PVP-HA) microneedles with embedded poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) were designed in order to achieve a sustained but relatively fast release of the enzyme to avoid its long exposure to water upon administration. PLGA-MPs with tunable porosity were produced by means of a modified double emulsion protocol and their morphological and kinetic properties were characterized by different analytic techniques. Diffusion studies and in vivo experiments were used to assess the release and indentation ability of the proposed MP-based microneedles. The obtained results recommend our bi-compartmental system as a promising biomedical technique paving the way for its efficient use in treating human diseases with labile therapeutic agents.


Assuntos
Colagenases/metabolismo , Microinjeções/métodos , Pele/metabolismo , Humanos
7.
Hum Vaccin Immunother ; 14(1): 45-58, 2018 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-29172945

RESUMO

Despite high vaccination coverage worldwide, pertussis has re-emerged in many countries. This randomized, controlled, observer-blind phase I study and extension study in Belgium (March 2012-June 2015) assessed safety and immunogenicity of investigational acellular pertussis vaccines containing genetically detoxified pertussis toxin (PT) (NCT01529645; NCT02382913). 420 healthy adults (average age: 26.8 ± 5.5 years, 60% female) were randomized to 1 of 10 vaccine groups: 3 investigational aP vaccines (containing pertussis antigens PT, filamentous hemagglutinin [FHA] and pertactin [PRN] at different dosages), 6 investigational TdaP (additionally containing tetanus toxoid [TT] and diphtheria toxoid [DT]), and 1 TdaP comparator containing chemically inactivated PT. Antibody responses were evaluated on days 1, 8, 30, 180, 365, and approximately 3 years post-booster vaccination. Cell-mediated immune responses and PT neutralization were evaluated in a subset of participants in pre-selected groups. Local and systemic adverse events (AEs), and unsolicited AEs were collected through day 7 and 30, respectively; serious AEs and AEs leading to study withdrawal were collected through day 365 post-vaccination. Antibody responses against pertussis antigens peaked at day 30 post-vaccination and then declined but remained above baseline level at approximately 3 years post-vaccination. Responses to FHA and PRN were correlated to antigen dose. Antibody responses specific to PT, toxin neutralization activity and persistence induced by investigational formulations were similar or significantly higher than the licensed vaccine, despite lower PT doses. Of 15 serious AEs, none were considered vaccination-related; 1 led to study withdrawal (premature labor, day 364; aP4 group). This study confirmed the potential benefits of genetically detoxified PT antigen. All investigational study formulations were well tolerated.


Assuntos
Vacinas contra Difteria, Tétano e Coqueluche Acelular/administração & dosagem , Imunização Secundária/métodos , Toxina Pertussis/imunologia , Vacina contra Coqueluche/administração & dosagem , Vacinação/métodos , Coqueluche/prevenção & controle , Adulto , Anticorpos Antibacterianos/análise , Bélgica , Vacinas contra Difteria, Tétano e Coqueluche Acelular/efeitos adversos , Vacinas contra Difteria, Tétano e Coqueluche Acelular/genética , Vacinas contra Difteria, Tétano e Coqueluche Acelular/imunologia , Feminino , Humanos , Imunidade Celular , Imunogenicidade da Vacina , Masculino , Toxina Pertussis/genética , Vacina contra Coqueluche/efeitos adversos , Vacina contra Coqueluche/genética , Vacina contra Coqueluche/imunologia , Resultado do Tratamento , Coqueluche/sangue , Coqueluche/imunologia , Adulto Jovem
8.
PLoS One ; 11(6): e0157066, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27336786

RESUMO

CD4+ T follicular helper cells (T(FH)) have been identified as the T-cell subset specialized in providing help to B cells for optimal activation and production of high affinity antibody. We recently demonstrated that the expansion of peripheral blood influenza-specific CD4(+)IL-21(+)ICOS1(+) T helper (T(H)) cells, three weeks after vaccination, associated with and predicted the rise of protective neutralizing antibodies to avian H5N1. In this study, healthy adults were vaccinated with plain seasonal trivalent inactivated influenza vaccine (TIIV), MF59(®)-adjuvanted TIIV (ATIIV), or saline placebo. Frequencies of circulating CD4(+) T(FH)1 ICOS(+) T(FH) cells and H1N1-specific CD4(+-)IL-21(+)ICOS(+) CXCR5(+) T(FH) and CXCR5(-) T(H) cell subsets were determined at various time points after vaccination and were then correlated with hemagglutination inhibition (HI) titers. All three CD4(+) T cell subsets expanded in response to TIIV and ATIIV, and peaked 7 days after vaccination. To demonstrate that these T(FH) cell subsets correlated with functional antibody titers, we defined an alternative endpoint metric, decorrelated HI (DHI), which removed any correlation between day 28/day 168 and day 0 HI titers, to control for the effect of preexisting immunity to influenza vaccine strains. The numbers of total circulating CD4(+)T(FH)1 ICOS(+) cells and of H1N1-specific CD4(+)IL-21(+)ICOS(+) CXCR5(+), measured at day 7, were significantly associated with day 28, and day 28 and 168 DHI titers, respectively. Altogether, our results show that CD4(+) T(FH) subsets may represent valuable biomarkers of vaccine-induced long-term functional immunity.


Assuntos
Formação de Anticorpos/imunologia , Imunidade , Contagem de Linfócitos , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Vacinação , Adolescente , Adulto , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Biomarcadores , Testes de Inibição da Hemaglutinação , Humanos , Imunofenotipagem , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Ativação Linfocitária/imunologia , Prognóstico , Vigilância em Saúde Pública , Receptores CXCR5/metabolismo , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Auxiliares-Indutores/metabolismo , Fatores de Tempo , Adulto Jovem
9.
PLoS One ; 10(6): e0129879, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26066485

RESUMO

Innate response activator (IRA) B cells have been described in mice as a subset of B-1a B cells that produce granulocyte/macrophage colony-stimulating factor (GM-CSF) and have been found in the spleen upon activation. In humans, identification, tissue localization and functionality of these lymphocytes are poorly understood. We hypothesized that IRA B cells could reside in human palatine tonsils, which are a first line of defense from infection of the upper respiratory tract. In the present work, we used flow cytometry and confocal microscopy to identify and characterize human IRA (hIRA) B cells in tonsils. We show that CD19⁺CD20⁺GM-CSF⁺ B cells are present in the tonsils of all the subjects studied at a frequency ranging between ~0.2% and ~0.4% of the conventional CD19⁺CD20⁺GM-CSF⁻ B cells. These cells reside within the B cell follicles, are mostly IgM⁺IgD⁺, express CD5 and show phagocytic activity. Our results support a role for hIRA B cells in the effector immune response to infections in tonsils.


Assuntos
Linfócitos B/imunologia , Tonsila Palatina/imunologia , Fagocitose , Adolescente , Antígenos CD19/genética , Antígenos CD19/metabolismo , Antígenos CD20/genética , Antígenos CD20/metabolismo , Linfócitos B/microbiologia , Antígenos CD5/genética , Antígenos CD5/metabolismo , Células Cultivadas , Criança , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Tonsila Palatina/citologia , Tonsila Palatina/microbiologia , Staphylococcus aureus/patogenicidade
10.
Vaccine ; 28(38): 6367-73, 2010 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-20619382

RESUMO

BACKGROUND: Hepatitis C virus (HCV) causes chronic liver disease that often leads to cirrhosis and hepatocellular carcinoma. In animal studies, chimpanzees were protected against chronic infection following experimental challenge with either homologous or heterologous HCV genotype 1a strains which predominate in the USA and Canada. We describe the first in humans clinical trial of this prophylactic HCV vaccine. METHODS: HCV E1E2 adjuvanted with MF59C.1 (an oil-in-water emulsion) was given at 3 different dosages on day 0 and weeks 4, 24 and 48 in a phase 1, placebo-controlled, dose escalation trial to healthy HCV-negative adults. RESULTS: There was no significant difference in the proportion of subjects reporting adverse events across the groups. Following vaccination subjects developed antibodies detectable by ELISA, CD81 neutralization and VSV/HCV pseudotype neutralization. There were no significant differences between vaccine groups in the number of responders and geometric mean titers for each of the three assays. All subjects developed lymphocyte proliferation responses to E1E2 and an inverse response to increasing amounts of antigen was noted. CONCLUSIONS: The vaccine was safe and generally well-tolerated at each of the 3 dosage levels and induced antibody and lymphoproliferative responses. A larger study to further evaluate safety and immunogenicity is warranted.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Hepacivirus/imunologia , Hepatite C/prevenção & controle , Polissorbatos/administração & dosagem , Esqualeno/administração & dosagem , Vacinas contra Hepatite Viral/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Proliferação de Células , Método Duplo-Cego , Feminino , Anticorpos Anti-Hepatite/sangue , Hepatite C/imunologia , Humanos , Esquemas de Imunização , Masculino , Pessoa de Meia-Idade , Vacinas contra Hepatite Viral/administração & dosagem , Vacinas contra Hepatite Viral/efeitos adversos , Adulto Jovem
11.
J Immunol ; 181(1): 174-85, 2008 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-18566382

RESUMO

Costimuli provide supplementary signals required by naive T cells to become fully activated upon Ag encounter. Tetraspanins are a large family of transmembrane proteins that can costimulate T cells when engaged in vitro. In this study, we describe for the first time that coligation of the tetraspanins CD81, CD82, or CD9 with the costimulatory molecule CD28 in vitro leads to proliferation of naive T cells. When activated through this pathway, both CD4+ and CD8+ naive T cells differentiate into type 2 effector cells, which produce IL-4, IL-5, IL-13, and IL-10, together with IL-2 and TNF-alpha, but little to no IFN-gamma. These effector cells descend from precursors that display early and strong production of IL-4, STAT6 phosphorylation, and up-regulation of the transcription factor GATA-3, suggesting a direct skewing toward Th2 differentiation without a Th0 intermediate. The hepatitis C virus envelope protein E2 is the only ligand known for CD81. Therefore, we propose that this new type of Ag-independent T cell activation may occur in hepatitis C virus-infected individuals, contributing to liver inflammation, impaired type 1 immune responses, and recurrent flares of type 2 immunity associated with chronic infection.


Assuntos
Antígenos CD/imunologia , Antígenos CD28/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Hepacivirus/imunologia , Imunidade Inata/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/imunologia , Membrana Celular/imunologia , Proliferação de Células , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Ligação Proteica , Tetraspanina 28
12.
J Gen Virol ; 87(Pt 8): 2253-2262, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16847121

RESUMO

Although approximately 3 % of the world's population is infected with Hepatitis C virus (HCV), there is no prophylactic vaccine available. This study reports the design, cloning and purification of a single polyprotein comprising the HCV core protein and non-structural proteins NS3, NS4a, NS4b, NS5a and NS5b. The immunogenicity of this polyprotein, which was formulated in alum, oil-in-water emulsion MF59 or poly(dl-lactide co-glycolide) in the presence or absence of CpG adjuvant, was then determined in a murine model for induction of B- and T-cell responses. The addition of adjuvants or a delivery system to the HCV polyprotein enhanced serum antibody and T-cell proliferative responses, as well as IFN-gamma responses, by CD4+ T cells. The antibody responses were mainly against the NS3 and NS5 components of the polyprotein and relatively poor responses were elicited against NS4 and the core components. IFN-gamma responses, however, were induced against all of the individual components of the polyprotein. These data suggest that the HCV polyprotein delivered with adjuvants induces broad B- and T-cell responses and could be a vaccine candidate against HCV.


Assuntos
Anticorpos Antivirais/sangue , Linfócitos T CD4-Positivos/imunologia , Hepacivirus/imunologia , Poliproteínas/imunologia , Vacinas contra Hepatite Viral/imunologia , Proteínas Virais/imunologia , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Compostos de Alúmen/farmacologia , Animais , Proliferação de Células , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Interferon gama/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Modelos Animais , Oligodesoxirribonucleotídeos/administração & dosagem , Oligodesoxirribonucleotídeos/farmacologia , Poliglactina 910/administração & dosagem , Poliproteínas/genética , Polissorbatos/administração & dosagem , Esqualeno/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Core Viral/genética , Proteínas do Core Viral/imunologia , Vacinas contra Hepatite Viral/genética , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Proteínas Virais/genética
13.
Proc Natl Acad Sci U S A ; 102(51): 18544-9, 2005 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-16339892

RESUMO

Infection with hepatitis C virus (HCV), a leading cause of chronic liver diseases, can associate with B lymphocyte proliferative disorders, such as mixed cryoglobulinemia and non-Hodgkin lymphoma. The major envelope protein of HCV (HCV-E2) binds, with high affinity CD81, a tetraspanin expressed on several cell types. Here, we show that engagement of CD81 on human B cells by a combination of HCV-E2 and an anti-CD81 mAb triggers the JNK pathway and leads to the preferential proliferation of the naïve (CD27-) B cell subset. In parallel, we have found that B lymphocytes from the great majority of chronic hepatitis C patients are activated and that naïve cells display a higher level of activation markers than memory (CD27+) B lymphocytes. Moreover, eradication of HCV infection by IFN therapy is associated with normalization of the activation-markers expression. We propose that CD81-mediated activation of B cells in vitro recapitulates the effects of HCV binding to B cell CD81 in vivo and that polyclonal proliferation of naïve B lymphocytes is a key initiating factor for the development of the HCV-associated B lymphocyte disorders.


Assuntos
Antígenos CD/metabolismo , Linfócitos B/metabolismo , Linfócitos B/patologia , Hepacivirus/fisiologia , Hepatite C/complicações , Ativação Linfocitária , Linfoma de Células B/patologia , Proliferação de Células , Células Cultivadas , Doença Crônica , Ativação Enzimática , Feminino , Regulação Viral da Expressão Gênica , Hepatite C/imunologia , Hepatite C/metabolismo , Hepatite C/virologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Linfoma de Células B/imunologia , Linfoma de Células B/metabolismo , Linfoma de Células B/virologia , Masculino , Pessoa de Meia-Idade , Receptores CXCR3 , Receptores de Quimiocinas/metabolismo , Transdução de Sinais , Tetraspanina 28
14.
Infect Immun ; 70(1): 368-79, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11748203

RESUMO

Chlamydia pneumoniae, a human pathogen causing respiratory infections and probably contributing to the development of atherosclerosis and heart disease, is an obligate intracellular parasite which for replication needs to productively interact with and enter human cells. Because of the intrinsic difficulty in working with C. pneumoniae and in the absence of reliable tools for its genetic manipulation, the molecular definition of the chlamydial cell surface is still limited, thus leaving the mechanisms of chlamydial entry largely unknown. In an effort to define the surface protein organization of C. pneumoniae, we have adopted a combined genomic-proteomic approach based on (i) in silico prediction from the available genome sequences of peripherally located proteins, (ii) heterologous expression and purification of selected proteins, (iii) production of mouse immune sera against the recombinant proteins to be used in Western blotting and fluorescence-activated cell sorter (FACS) analyses for the identification of surface antigens, and (iv) mass spectrometry analysis of two-dimensional electrophoresis (2DE) maps of chlamydial protein extracts to confirm the presence of the FACS-positive antigens in the chlamydial cell. Of the 53 FACS-positive sera, 41 recognized a protein species with the expected size on Western blots, and 28 of the 53 antigens shown to be surface-exposed by FACS were identified on 2DE maps of elementary-body extracts. This work represents the first systematic attempt to define surface protein organization in C. pneumoniae.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Chlamydophila pneumoniae/genética , Genoma Bacteriano , Animais , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Western Blotting/métodos , Feminino , Citometria de Fluxo/métodos , Expressão Gênica , Humanos , Camundongos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
15.
J Gen Virol ; 81(Pt 10): 2451-2459, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10993933

RESUMO

The antibody response to the envelope proteins of hepatitis C virus (HCV) may play an important role in controlling the infection. To allow molecular analyses of protective antibodies, we isolated human monoclonal antibodies to the E2 envelope glycoprotein of HCV from a combinatorial Fab library established from bone marrow of a chronically HCV-infected patient. Anti-E2 reactive clones were selected using recombinant E2 protein. The bone marrow donor carried HCV genotype 2b, and E2 used for selection was of genotype 1a. The antibody clones were expressed as Fab fragments in E. coli, and as Fab fragments and IgG1 in CHO cells. Seven different antibody clones were characterized, and shown to have high affinity for E2, genotype 1a. Three clones also had high affinity for E2 of genotype 1b. They all bind to conformation-dependent epitopes. Five clones compete for the same or overlapping binding sites, while two bind to one or two other epitopes of E2. Four clones corresponding to the different epitopes were tested as purified IgG1 for blocking the CD81-E2 interaction in vitro; all four were positive at 0.3-0.5 microg/ml. Thus, the present results suggest the existence of at least two conserved epitopes in E2 that mediate inhibition of the E2-CD81 interaction, of which one appeared immunodominant in this donor.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Antígenos CD/metabolismo , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/isolamento & purificação , Proteínas de Membrana , Proteínas do Envelope Viral/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/genética , Medula Óssea/virologia , Células CHO , Cricetinae , Mapeamento de Epitopos , Genótipo , Hepacivirus/genética , Humanos , Fragmentos Fab das Imunoglobulinas/biossíntese , Imunoglobulina G/biossíntese , Dados de Sequência Molecular , Conformação Proteica , Relação Quantitativa Estrutura-Atividade , Proteínas Recombinantes/imunologia , Tetraspanina 28 , Doadores de Tecidos
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