RESUMO
We have studied the effect of chemical composition of biodiesel fuel on the physical (volatility) and chemical (reactive oxygenated species concentration) properties of nano particles emitted from a modern common-rail diesel engine. Particle emissions from the combustion of four biodiesels with controlled chemical compositions and different varying unsaturation degrees and carbon-chain lengths, together with a commercial diesel, were tested and compared in terms of volatility of particles and the amount of reactive oxygenated species carried by particles. Different blends of biodiesel and petro diesel were tested at several engine loads and speeds. We have observed that more saturated fuels with shorter carbon chain lengths result in lower particle mass but produce particles that are more volatile and also have higher levels of Reactive Oxygen Species. This highlights the importance of taking into account metrics that are relevant from the health effects point of view when assessing emissions from new fuel types.
Assuntos
Biocombustíveis/análise , Material Particulado/análise , Emissões de Veículos/análise , Estrutura Molecular , Oxirredução , Material Particulado/química , VolatilizaçãoRESUMO
Generally, the magnitude of pollutant emissions from diesel engines running on biodiesel fuel is ultimately coupled to the structure of the fuel's constituent molecules. Previous studies demonstrated the relationship between the organic fraction of particulate matter (PM) and its oxidative potential. Herein, emissions from a diesel engine running on different biofuels were analyzed in more detail to explore the role that different organic fractions play in the measured oxidative potential. In this work, a more detailed chemical analysis of biofuel PM was undertaken using a compact time of flight aerosol mass spectrometer (c-ToF AMS). This enabled a better identification of the different organic fractions that contribute to the overall measured oxidative potentials. The concentration of reactive oxygen species (ROS) was measured using a profluorescent nitroxide molecular probe 9-(1,1,3,3-tetramethylisoindolin-2-yloxyl-5-ethynyl)-10-(phenylethynyl)anthracene (BPEAnit). Therefore, the oxidative potential of the PM, measured through the ROS content, although proportional to the total organic content in certain cases, shows a much higher correlation with the oxygenated organic fraction as measured by the c-ToF AMS. This highlights the importance of knowing the surface chemistry of particles for assessing their health impacts. It also sheds light onto new aspects of particulate emissions that should be taken into account when establishing relevant metrics for assessing health implications of replacing diesel with alternative fuels.
Assuntos
Aerossóis/química , Gasolina , Compostos Orgânicos/química , Oxigênio/química , Material Particulado , OxirreduçãoRESUMO
OBJECTIVE: This case report discusses a successful emergency Lichtenberger lateralisation procedure after immediate bilateral laryngeal immobility, occurring after total thyroidectomy. METHODS: A 63-year-old female with right-sided vocal fold paralysis due to compression by a multinodular thyroid goitre underwent total thyroidectomy, which resulted in immediate post-operative bilateral vocal fold immobility. The patient had acute-onset post-operative dyspnoea, was promptly re-intubated, and an emergency lateralisation Lichtenberger suture was placed over the right vocal fold and fixated on the outer surface of the neck. RESULTS: After two weeks, her right vocal fold recovered first, with the suture still in place. At four weeks, both vocal folds regained function and the suture was extracted. CONCLUSION: The take-away message is that an emergency lateralisation suture may be a viable option in maintaining airway patency, while allowing for normal deglutition, in patients who would otherwise be candidates for prolonged intubation, posterior cordotomy, medial arytenoidectomy or tracheostomy.
Assuntos
Tireoidectomia , Paralisia das Pregas Vocais , Humanos , Feminino , Pessoa de Meia-Idade , Tireoidectomia/efeitos adversos , Paralisia das Pregas Vocais/etiologia , Paralisia das Pregas Vocais/cirurgia , Prega Vocal , Traqueostomia/efeitos adversos , Dispneia/etiologia , Dispneia/cirurgiaRESUMO
This study undertook a physicochemical characterization of particle emissions from a single compression ignition engine operated at one test mode with 3 biodiesel fuels made from 3 different feedstocks (i.e., soy, tallow, and canola) at 4 different blend percentages (20%, 40%, 60%, and 80%) to gain insights into their particle-related health effects. Particle physical properties were inferred by measuring particle number size distributions both with and without heating within a thermodenuder (TD) and also by measuring particulate matter (PM) emission factors with an aerodynamic diameter less than 10 µm (PM(10)). The chemical properties of particulates were investigated by measuring particle and vapor phase Polycyclic Aromatic Hydrocarbons (PAHs) and also Reactive Oxygen Species (ROS) concentrations. The particle number size distributions showed strong dependency on feedstock and blend percentage with some fuel types showing increased particle number emissions, while others showed particle number reductions. In addition, the median particle diameter decreased as the blend percentage was increased. Particle and vapor phase PAHs were generally reduced with biodiesel, with the results being relatively independent of the blend percentage. The ROS concentrations increased monotonically with biodiesel blend percentage but did not exhibit strong feedstock variability. Furthermore, the ROS concentrations correlated quite well with the organic volume percentage of particles - a quantity which increased with increasing blend percentage. At higher blend percentages, the particle surface area was significantly reduced, but the particles were internally mixed with a greater organic volume percentage (containing ROS) which has implications for using surface area as a regulatory metric for diesel particulate matter (DPM) emissions.
Assuntos
Poluentes Atmosféricos/química , Biocombustíveis/análise , Material Particulado/química , Poluentes Atmosféricos/análise , Conservação de Recursos Energéticos , Tamanho da Partícula , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Espécies Reativas de Oxigênio/análise , Medição de Risco , Emissões de VeículosRESUMO
By analyzing T cell responses against foreign major histocompatibility complex (MHC) molecules loaded with peptide libraries and defined self- and viral peptides, we demonstrate a profound influence of self-MHC molecules on the repertoire of alloreactive T cells: the closer the foreign MHC molecule is related to the T cell's MHC, the higher is the proportion of peptide-specific, alloreactive ("allorestricted") T cells versus T cells recognizing the foreign MHC molecule without regard to the peptide in the groove. Thus, the peptide repertoire of alloreactive T cells must be influenced by self-MHC molecules during positive or negative thymic selection or peripheral survival, much like the repertoire of the self-restricted T cells. In consequence, allorestricted, peptide-specific T cells (that are of interest for clinical applications) are easier to obtain if T cells and target cells express related MHC molecules.
Assuntos
Genes MHC Classe I/imunologia , Antígenos H-2/imunologia , Oligopeptídeos/imunologia , Linfócitos T/imunologia , Animais , Linhagem Celular , Variação Genética , Antígenos H-2/genética , Camundongos , Camundongos Endogâmicos C57BL , Biblioteca de Peptídeos , Linfócitos T/citologia , Linfócitos T Citotóxicos , Vírus da Estomatite Vesicular Indiana/imunologiaRESUMO
Peptide fragments of foreign and self-proteins are of great immunologic importance as their binding to major histocompatibility complex (MHC) class I or II molecules makes an interaction with a corresponding T cell receptor possible. Recently, allele-specific peptide sequence motifs proved to be responsible for MHC binding, no matter whether self- or non-self-antigens were involved. Up to now, all investigated human class II-associated peptides were derived from foreign antigenic proteins. Therefore, we undertook sequence and binding analyses with a 16-mer self-peptide (SP3) that has been eluted from HLA-DR1. Here we demonstrate, by synthetic polyalanine-based 13-mer analogues of SP3, that two bulky hydrophobic anchor residues with relative spacing i, i + 8 are sufficient for high affinity binding. This is consistent with the hydrophobic i, i + 8 binding pattern recently found for DR-restricted T cell epitopes. Nevertheless, highly helical alanine-based design peptides with anchor spacing i, i + 9 exhibit maximal affinity, whereas replacement of alanine by helix destabilizing proline abrogates binding. Thus, a two-residue contact motif is the common minimal requirement of self- and foreign peptides for high affinity anchoring to HLA-DR1. In contrast to class I, the anchor spacing of DR1-associated peptides seems to bear some variability due to conformational diversity.
Assuntos
Antígeno HLA-DR1/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/imunologia , Sequência de Aminoácidos , Linhagem Celular Transformada , Epitopos/análise , Antígeno HLA-DR1/química , Herpesvirus Humano 4/genética , Humanos , Cinética , Complexo Principal de Histocompatibilidade , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Homologia de Sequência do Ácido NucleicoRESUMO
Nearly half of HLA-A2-positive individuals in African populations have a subtype of HLA-A2 other than the A*0201 allele. We have isolated the common African HLA-A2 subtype genes from Epstein-Barr virus-transformed B cell lines and have established stable class I reduced transfectants expressing these alleles. We have studied the peptide binding and presentation properties of A*0201, A*0202, A*0205, A*0214, and A*6901 by a combination of approaches: assaying direct binding of labeled synthetic peptides, studying the ability of antigen-specific cytotoxic T lymphocytes to recognize peptide-pulsed cells, and sequencing peptide pools and individual ligands eluted from cells. We find that A*0201-restricted peptides can also bind to A*0202 but do not bind strongly to the other alleles in this study. We show that some cytotoxic T lymphocytes can recognize all subtypes capable of binding an antigenic peptide, whereas others are subtype specific. Sequencing of eluted peptides reveals that A*0202 has a similar peptide motif to A*0201, but that A*0205, A*0214, and A*6901 have different motifs. These data strongly support a model in which residue 9 (Phe or Tyr) of the A2/A68/A69 molecules is a critical factor in determining the specificity of the B pocket of the major histocompatibility complex and the position 2 anchor residue of associated peptides. We conclude that a single-amino acid difference in the major histocompatibility complex can be sufficient to cause a dramatic change in the nature of bound peptides, implying that individuals with closely related HLA subtypes may present very different repertoires of antigenic peptides to T cells in an immune response. It is likely to be a general phenomenon that very similar class I subtypes will behave as functionally distinct HLA allotypes.
Assuntos
Células Apresentadoras de Antígenos/metabolismo , Antígeno HLA-A2/metabolismo , Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologia , Alelos , Sequência de Aminoácidos , Antígeno HLA-A2/classificação , Antígeno HLA-A2/genética , Humanos , Ligantes , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/metabolismo , Ligação Proteica , TransfecçãoRESUMO
Proteasomes are the main proteases responsible for cytosolic protein degradation and the production of major histocompatibility complex class I ligands. Incorporation of the interferon gamma--inducible subunits low molecular weight protein (LMP)-2, LMP-7, and multicatalytic endopeptidase complex--like (MECL)-1 leads to the formation of immunoproteasomes which have been associated with more efficient class I antigen processing. Although differences in cleavage specificities of constitutive and immunoproteasomes have been observed frequently, cleavage motifs have not been described previously. We now report that cells expressing immunoproteasomes display a different peptide repertoire changing the overall cytotoxic T cell--specificity as indicated by the observation that LMP-7(-/-) mice react against cells of LMP-7 wild-type mice. Moreover, using the 436 amino acid protein enolase-1 as an unmodified model substrate in combination with a quantitative approach, we analyzed a large collection of peptides generated by either set of proteasomes. Inspection of the amino acids flanking proteasomal cleavage sites allowed the description of two different cleavage motifs. These motifs finally explain recent findings describing differential processing of epitopes by constitutive and immunoproteasomes and are important to the understanding of peripheral T cell tolerization/activation as well as for effective vaccine development.
Assuntos
Cisteína Endopeptidases/metabolismo , Complexos Multienzimáticos/metabolismo , Fragmentos de Peptídeos/metabolismo , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Animais , Células Cultivadas , Cisteína Endopeptidases/química , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/imunologia , Epitopos , Feminino , Complexo Principal de Histocompatibilidade , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos Mutantes , Dados de Sequência Molecular , Complexos Multienzimáticos/química , Complexos Multienzimáticos/imunologia , Fragmentos de Peptídeos/análise , Mapeamento de Peptídeos , Fosfopiruvato Hidratase/química , Fosfopiruvato Hidratase/metabolismo , Complexo de Endopeptidases do Proteassoma , Proteínas/genética , Proteínas/metabolismo , Transplante de Pele/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
OBJECTIVE: In 95% of patients with primary biliary cirrhosis (PBC) antimitochondrial antibodies (AMAs) can be detected reacting with at least one of the five components of the M2 antigen identified as the 2-oxoacid dehydrogenase complex (OADC). However, among our PBC sera 15-20% are anti-M2 negative by ELISA and western blotting but in the immunofluorescence test (IFT) they show the typical AMA staining. The aim of the present study was to characterise the target antigen(s) of these non-M2-related AMAs. PATIENTS AND METHODS: We analysed sera from 27 patients with clinically and histologically proven PBC being AMA positive by the IFT but anti-M2 negative by ELISA and western blotting. They were tested by western blotting against various 100,000 g supernatants obtained after sonication of mitochondria from rat liver, bovine heart and pig kidney. These were further separated by isopycnic sucrose density centrifugation using different sucrose density fractions. RESULTS: Fourteen of the 27 AMA positive/anti-M2 negative sera (52%) reacted in the western blotting with a 60 kDa protein and eight (29%) with an 80 kDa protein, both present in the 100 000 g supernatant from bovine heart mitochondria accumulating at sucrose densities of 1.14-1.16. An identity of these determinants with any of the M2-related antigens could be excluded. In the 60 kDa band components of the mitochondrial enzymes F(1)F(0)-ATPase, ubiquinone cytochrome c reductase and acyl CoA dehydrogenase were detected by MALDI-TOF analysis; the 80 kDa protein could not be further characterised. CONCLUSIONS: AMA positive/anti-M2 negative PBC sera contain antibodies to further mitochondrial antigens at 60 and 80 kDa which do not correspond to any of the M2 determinants. Those antibodies can be detected to a lesser extent in sera from patients with classical anti-M2 positive PBC but not in patients with other hepatic and non-hepatic disorders and may, therefore, represent additional marker antibodies for the serological diagnosis of PBC.
Assuntos
Autoanticorpos/imunologia , Cirrose Hepática Biliar/imunologia , Mitocôndrias Hepáticas/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto JovemRESUMO
The antigenic makeup of tumour cells can have a profound effect on the progression of cancer and success of immunotherapies. Therefore, one strategy to improve the efficacy of cancer treatments is to augment the antigens displayed by tumours. The present study explores how the recognition of tumour cells may be altered by non-cytotoxic concentrations of gemcitabine (GEM). Testing a panel of chemotherapeutics in human cancer cell lines in vitro, it was found that GEM increased surface expression of HLA-A,B,C and that underlying this were specific increases in ß-2-microglobulin and immunoproteasome subunit proteins. Furthermore, the peptide antigen repertoire displayed on HLA class I was altered, revealing a number of novel antigens, many of which that were derived from proteins involved in the DNA-damage response. Changes in the nature of the peptide antigens eluted from HLA-A,B,C after GEM treatment consisted of amino acid anchor-residue modifications and changes in peptide length which rendered peptides likely to favour alternative HLA-alleles and increased their predicted immunogenicity. Signalling through the MAPK/ERK and NFκB/RelB pathways was associated with these changes. These data may explain observations made in previous in vivo studies, advise as to which antigens should be used in future vaccination protocols and reinforce the idea that chemotherapy and immunotherapy could be used in combination.
RESUMO
BACKGROUND: The physiological functions of the classical HLA (human leukocyte antigen) molecules, HLA-A, HLA-B and HLA-C, are to present peptides to T cells and to inhibit the activity of natural killer cells. In contrast, the functions of nonclassical HLA-molecules, such as HLA-E, HLA-F and HLA-G, remain to be established. The expression of HLA-G is largely limited to the placental trophoblast, where it might mediate protection of the fetus from rejection by the mother. Achieving the aim of understanding the function of HLA-G should be facilitated by information on the biochemical properties of HLA-G molecules, especially on their potential ability to act as peptide receptors. RESULTS: To study peptide presentation by HLA-G, we used stably transfected LCL721.221 cells as a source of HLA-G molecules and analysed the spectrum of extracted peptides by individual and pool sequencing. Our results indicate that HLA-G molecules, like classical HLA molecules, are associated with a wide array of peptides derived from cellular proteins. Peptides presented by HLA-G usually consisted of 9 amino acids, and adhered to a specific sequence motif, with anchor residues at position 2 (isoleucine or leucine), position 3 (proline) and the carboxy-terminal position 9 (leucine). Thus, the HLA-G peptide ligand motif follows the principles of classical HLA motifs, although it displays its own unique features. Peptide-binding assays indicated that two of the three anchor residues were sufficient for binding, and that the three natural HLA-G ligands that we identified bound, not only to HLA-G, but also to HLA-A2. This was not surprising, because the binding pockets of HLA-A2 and HLA-G overlap in their ability to recognize anchor residues at positions 2 and 9. Likewise, some, but not all, HLA-A2 peptide ligands could also bind to HLA-G. CONCLUSIONS: Nonclassical HLA-G molecules present peptides essentially in the same way as classical HLA molecules do. We determined the peptide motif that is specifically recognized by HLA-G; its basic features are described by the sequence XI/LPXXXXXL: This information should help to elucidate the physiological role of HLA-G molecules at the fetal-maternal interface. Most likely, this role is to protect fetal cells from lysis by natural killer cells, and possibly to present foreign peptides to a class of T cells that has not yet been identified.
Assuntos
Apresentação de Antígeno , Antígenos HLA/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Peptídeos/imunologia , Sequência de Aminoácidos , Linhagem Celular Transformada , Antígenos HLA/química , Antígenos HLA/genética , Antígenos HLA-G , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Ligantes , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/isolamento & purificação , TransfecçãoRESUMO
It has been shown previously that sera from patients with cholestatic liver diseases react with sulphite oxidase (SO) prepared from chicken liver. In order to analyse this reactivity and the clinical relevance of anti-SO antibodies in more detail, we produced human recombinant SO. Human recombinant SO (60 kDa) was expressed in Escherichia coli and applied to enzyme-linked immunosorbent assay and Western blot. Sera from patients with autoimmune liver disorders [primary biliary cirrhosis (PBC) n = 96; autoimmune hepatitis (AIH) n = 77; primary sclerosing cholangitis (PSC) n = 39], and from patients with other hepatic (n = 154) and non-hepatic chronic inflammatory disorders (n = 113) were investigated. Highest incidence and activities of IgG-anti-SO antibodies were observed in PSC patients. Nine of 16 untreated (56%) and four of 23 PSC patients treated with ursodeoxycholic acid (UDCA) (17%) were positive. Antibody activity decreased significantly during UDCA treatment. Five per cent of PBC and 9% of AIH patients, but also 15% of patients with alcoholic liver disease, were IgG anti-SO-positive. In patients with viral hepatitis and non-hepatic disorders they could be hardly detected. Anti-SO antibodies are further anti-mitochondrial antibodies in chronic liver diseases. They occur predominantly in PSC, and UDCA treatment seams to decrease antibody activity. Whether these antibodies are primary or secondary phenomena and whether they are related to the aetiology or pathogenesis, at least in a subgroup of patients with chronic liver diseases, has still to be evaluated.
Assuntos
Autoanticorpos/sangue , Doenças Autoimunes/imunologia , Hepatopatias/imunologia , Sulfito Oxidase/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Colangite Esclerosante/imunologia , Doença Crônica , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli/enzimologia , Feminino , Hepatite Autoimune/imunologia , Humanos , Cirrose Hepática Biliar/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/imunologiaRESUMO
Three of the most promising antigens for immunotherapy of chronic myelogenous leukaemia (CML) include the specific fusion-protein, Bcr/Abl, and the overexpressed proteins WT1 and Proteinase 3. The clinical significance of Proteinase 3 as a target in myelogenous leukaemias has been bolstered by detection of high frequencies of cytotoxic CD8+ lymphocytes specific for this antigen in patients undergoing immune therapies. Our investigation aimed to directly identify MHC-ligands derived from these antigens and presented on CML blasts by means of affinity-purification and mass spectrometric peptide-sequencing. Although no known or potential new epitopes were discovered for Bcr/Abl or WT1, a novel peptide from Proteinase 3 was detected among the more abundant MHC-ligands. Additionally, MHC-ligands derived from known immunogenic proteins overexpressed as a result of Bcr/Abl transformation were also identified. Our investigation is the second of only a small number of studies to identify a peptide from Proteinase 3 among the more abundant MHC-associated peptides and thus implies that peptides from this antigen are among the more abundantly presented of the known leukaemic antigens. Taken in conjunction with clinical observations of functional Proteinase 3 specific CTL in patients', these data further support the application of this antigen as an immunotherapeutical target for myelogenous leukaemias.
Assuntos
Antígenos de Histocompatibilidade Classe I/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Proteínas de Neoplasias/imunologia , Fragmentos de Peptídeos/imunologia , Serina Endopeptidases/imunologia , Epitopos/imunologia , Antígenos HLA-B/química , Antígenos HLA-B/imunologia , Antígenos HLA-DR/química , Antígenos HLA-DR/imunologia , Antígenos HLA-DR/isolamento & purificação , Antígenos de Histocompatibilidade Classe I/química , Humanos , Imunofenotipagem , Imunoterapia , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Ligantes , Mieloblastina , Proteínas de Neoplasias/química , Proteínas de Neoplasias/isolamento & purificação , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Serina Endopeptidases/químicaRESUMO
Caries is the most common disease in the world. Great efforts have been undertaken for prevention and to identify a regenerative treatment solution for dental caries. Self-assembling ß-sheet forming peptides have previously shown to form 3-dimensional fiber networks supporting tissue regeneration. In particular, the self-assembling peptide P11-4 has shown potential in the treatment and prevention of dental caries. It has previously been shown that application of monomeric P11-4 solution to early carious lesions can increase net mineral gain by forming de novo hydroxyapatite crystals. The hypothesis for the mode of action was that monomeric self-assembling peptide P11-4 diffuses into the subsurface lesion body and assembles therein into higher order fibrils, facilitating mineralization of the subsurface volume by mimicking the natural biomineralization of the tooth enamel, and it remains within the lesion body as a scaffold built-in by the newly formed hydroxyapatite. The aim of the present study was to investigate the mechanism of action of the self-assembling peptide P11-4 supporting mineralization of carious enamel. By various analytical methods, it could be shown that the self-assembling peptide P11-4 diffuses into the subsurface lesion, assembles into higher formed aggregates throughout the whole volume of the lesion, and supports nucleation of de novo hydroxyapatite nanocrystals and consequently results in increased mineral density within the subsurface carious lesion. The results showed that the application of self-assembling peptide P11-4 can facilitate the subsurface regeneration of the enamel lesion by supporting de novo mineralization in a similar mode of action as has been shown for the natural formation of dental enamel.
Assuntos
Materiais Biomiméticos/química , Cárie Dentária/terapia , Esmalte Dentário/efeitos dos fármacos , Oligopeptídeos/química , Remineralização Dentária/métodos , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Propriedades de Superfície , Microtomografia por Raio-XRESUMO
The Her-2/neu oncogene encodes a Mr 185,000 transmembrane protein with homology to the epidermal growth factor receptor. It is overexpressed in 30-40% of breast and ovarian cancers, and this overexpression was shown to correlate with aggressiveness of malignancy and poor prognosis. Using tumor-associated lymphocytes isolated from patients with ovarian or breast cancer, several HLA-A2-restricted, Her-2/neu-derived peptides were identified. Further studies revealed that these tumor-associated CTLs can also lyse other tumors, including non-small cell lung and pancreatic cancer cells, suggesting that Her-2/neu epitopes are shared between several distinct types of epithelial tumors. To analyze whether Her-2/neu epitopes are tumor-associated antigens for renal cell carcinoma (RCC) and colon carcinoma, we induced Her-2/neu peptide-specific CTL responses by primary in vitro immunization and used these CTLs to determine the presentation of Her-2/neu epitopes on human tumor lines. Autologous dendritic cells (DCs) generated from peripheral blood monocytes were pulsed with Her-2/neu-derived peptides E75 and GP2 and used as antigen-presenting cells for CTL priming. High CTL activity toward peptide-pulsed targets was obtained after two weekly restimulations. CTLs induced with DCs generated in the presence of TNF-alpha elicited a higher cytotoxic activity when they were stimulated with the cognate peptide than did CTLs induced with DCs grown in granulocyte macrophage colony-stimulating factor and interleukin 4 alone. The cytotoxicity of induced CTLs was antigen specific and HLA-A2 restricted. Furthermore, these CTLs lysed, in a MHC- and antigen-restricted fashion, not only breast cancer cells but also colon carcinoma and RCC cell lines expressing Her-2/neu. The cytotoxic activity against tumor cells was blocked by cold HLA-A2-positive targets pulsed with the cognate peptide in cold target inhibition assay and by anti-HLA-A2 monoclonal Ab. These results suggest that epitopes derived from Her-2/neu protein might be attractive candidates for broadly applicable vaccines and may prove useful for adoptive immunotherapies designed for colon carcinoma or RCC.
Assuntos
Antígenos de Neoplasias/imunologia , Neoplasias do Colo/imunologia , Neoplasias Renais/imunologia , Receptor ErbB-2/imunologia , Linfócitos T Citotóxicos/imunologia , Neoplasias da Mama/imunologia , Linhagem Celular , Células Dendríticas , Antígeno HLA-A2/imunologia , Humanos , Peptídeos/imunologia , Células Tumorais CultivadasRESUMO
Peptides presented by HLA-A*0201 molecules on the surface of the human breast carcinoma cell line KS24.22 after IFN-gamma induction were analyzed by the "Predict-Calibrate-Detect" approach, which combines epitope prediction and high-performance liquid chromatography mass spectrometry. One of the predicted epitopes, MAGE-A1(278-286) (KVLEYVIKV), was found to be presented by HLA-A*0201, with an estimated copy number of 18 molecules/cell. HLA-A*0201 transgenic mice (HHD mice) were used to generate CTL lines that stained positive with an HLA-A*0201 tetramer folded around the KVLEYVIKV peptide and killed peptide-loaded mouse target cells expressing HLA-A*0201. IFN-gamma-treated or -nontreated HLA-A*0201 expressing HeLa cells transiently transfected with a plasmid expressing the MAGE-A1 gene stimulated in vitro cytokine production by the CTL lines. Moreover, IFN-gamma-treated KS24.22 cells, but not IFN-gamma-treated HLA-A*0201(+) MAGE-A1(-) cells or IFN-gamma-treated HLA-A*0201(-) MAGE-A1(+) cells, were killed by these CTLS: Thus, the combination of HLA epitope prediction, peptide analysis, and immunological methods is a powerful approach for the identification of tumor-associated epitopes.
Assuntos
Antígenos de Neoplasias/imunologia , Epitopos de Linfócito T/análise , Antígeno HLA-A2/imunologia , Proteínas de Neoplasias/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Neoplasias/genética , Neoplasias da Mama/imunologia , Cromatografia Líquida de Alta Pressão , Epitopos de Linfócito T/imunologia , Células HeLa , Humanos , Espectrometria de Massas , Antígenos Específicos de Melanoma , Camundongos , Proteínas de Neoplasias/genética , Fragmentos de Peptídeos/imunologia , Mapeamento de Peptídeos , Linfócitos T Citotóxicos/imunologia , Transfecção , Células Tumorais CultivadasRESUMO
The identification of tumor-associated antigens recognized by CD8+ cytotoxic T cells paved the way to new concepts in adjuvant anticancer therapy. However, the number of tumor-associated proteins found to be expressed in the majority of human cancers is still rather limited. Recently, the newly identified apoptosis inhibitor protein survivin has been recognized as a widely occurring tumor-associated protein. In the present study, we demonstrate that survivin is capable of inducing specific CD8+ effector T cells in vitro. T cells from healthy donors were subjected to several cycles of stimulation by autologous dendritic cells (DCs) pulsed with soluble recombinant survivin protein. Activation of CD8+ cytotoxic T cells by survivin-derived peptides cross-presented by DCs was demonstrated by lysis of autologous survivin-expressing B cell transfectants. Using a peptide-motif scoring system, two survivin peptides (ELTLGE-FLKL and TLPPAWQPFL) were predicted and proved to bind to the HLA-A*0201 molecule. Both peptides were shown to induce CD8+ effector T cells when presented on DCs; one peptide could be verified to result from natural intracellular processing of survivin. These findings recommend survivin as a new and widely applicable target for protein- and peptide-based immunotherapy of tumors.
Assuntos
Células Dendríticas/imunologia , Proteínas Associadas aos Microtúbulos , Fragmentos de Peptídeos/imunologia , Proteínas/imunologia , Linfócitos T Reguladores/imunologia , Sequência de Aminoácidos , Apresentação de Antígeno/imunologia , Comunicação Celular/imunologia , Células Dendríticas/efeitos dos fármacos , Epitopos de Linfócito T/imunologia , Antígenos HLA-A/imunologia , Antígenos HLA-A/metabolismo , Humanos , Proteínas Inibidoras de Apoptose , Células Jurkat , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Proteínas de Neoplasias , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Proteínas/metabolismo , Survivina , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
Introducción: En 2015 se aplicaron en España distintas medidas para la minimización de los riesgos (MMR) del ácido valproico. Objetivo: El objetivo de este estudio es evaluar la eficacia de las MMR del ácido valproico en España, con el fin de reducir el uso de ácido valproico como terapia de primera línea y evaluar los patrones de prescripción de ácido valproico en las mujeres, incluidas las mujeres en edad fértil (MEF), en los períodos previos y posteriores a la implementación de las MMR. Materiales y métodos: Los patrones de prescripción del ácido valproico en mujeres y MEF antes y después de la implementación de las MMR se examinaron utilizando la base de datos longitudinales de pacientes (longitudinal patient data, LPD por sus siglas en inglés), que incluye información de pacientes de dos paneles: médicos de atención primaria (MAP) y neurólogos/psiquiatras. El criterio principal de valoración fue la proporción de prescripciones iniciales de ácido valproico con al menos un medicamento relacionado con indicaciones de ácido valproico antes de la fecha de inicio del ácido valproico. Resultados: La proporción de prescripciones de ácido valproico secundarias con uso previo de medicamentos relacionados con indicaciones de ácido valproico fue del 78% intervalo de confianza (IC) al 95%: 73,9-81,5% y del 78,2% (IC al 95%: 74,5-81,4%) en los períodos principales previo y posterior a la implementación en el panel de MAP. Las cifras correspondientes a MEF fueron del 79,6% (IC al 95%: 73,6-84,5%) y del 75,5% (IC al 95%: 69,7-80,6%), respectivamente. La tasa de incidencia de embarazos expuestos al ácido valproico (por 1.000 personas-años) en MEF disminuyó de 17,4 en el período completo previo a la implementación a 8,5 en el período completo posterior a la implementación...(AU)
Introduction: Risk minimisation measures for valproate were implemented in Spain in 2015.Objective: The objective of this study is to assess the effectiveness of valproate risk minimisation measures in Spain intended to decrease the use of valproate as a first-line therapy, and to evaluate the prescribing patterns of valproate in women, including women of childbearing potential, in the pre- and post-implementation risk minimisation measures periods. Materials and methods: The prescribing patterns of valproate in females and women of childbearing potential before and after risk minimisation measures implementation were examined using the longitudinal patient data database, which includes patient information from two panels: primary care physicians and neurologists/psychiatrists. Primary endpoint was the proportion of initial valproate prescriptions with at least one medication related to the valproate indications before the valproate initiation date. Results: The proportion of incident valproate prescriptions with previous use of medication related to valproate indications was 78.0% (95% CI, 73.9%; 81.5%), and 78.2% (74.5%; 81.4%) in the main pre-and post-implementation periods in the primary care physician panel. The corresponding figures for women of childbearing potential were 79.6% (73.6%; 84.5%) and 75.5% (69.7%; 80.6%), respectively. The incidence rate of pregnancies exposed to valproate (per 1,000 person-years) in women of childbearing potential decreased from 17.4 the entire pre-implementation to 8.5 in the entire post-implementation periods. Conclusion: After the implementation of risk minimisation measures for valproate in Spain, no meaningful change in prescribing was observed regarding the proportion of valproate initiations preceded by prior medication related to valproate indications. The preventative measures recommended for use of valproate in women of childbearing potential should be considered.(AU)
Assuntos
Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Transtorno Bipolar/tratamento farmacológico , Epilepsia/tratamento farmacológico , Uso de Medicamentos , Ácido Valproico/efeitos adversos , Síndromes Epilépticas/tratamento farmacológico , Prescrições de Medicamentos , Espanha , Neurologia , Doenças do Sistema Nervoso , Neuropsiquiatria , Estudos de Coortes , Reino Unido , Suécia , Alemanha , FrançaRESUMO
Oxidative potential (OP) is related to the organic phase, specifically to its oxygenated organic fraction (OOA). Furthermore, the oxygen content of fuel molecules has significant influence on particulate OP. Thus, this study aimed to explore the actual dependency of the OOA and ROS to the oxygen content of the fuel. In order to reach the goal, different biodiesels blends, with various ranges of oxygen content; have been employed. The compact time of flight aerosol mass spectrometer (c-ToF AMS) enabled better identification of OOA. ROS monitored by using two assays: DTT and BPEA-nit. Despite emitting lower mass, both assays agreed that oxygen content of a biodiesel is directly correlated with its OOA, and highly related to its OP. Hence, the more oxygen included in the considered biodiesels, the higher the OP of PM emissions. This highlights the importance of taking oxygen content into account while assessing emissions from new fuel types, which is relevant from a health effects standpoint.