RESUMEN
Recent reports identify the ratio between absolute neutrophil count (ANC) and absolute lymphocyte count (ALC), called neutrophil to lymphocyte ratio (NLR), as a predictor of progression-free survival (PFS) and overall survival (OS) in various malignancies. We retrospectively examined the NLR in a cohort of 309 newly diagnosed multiple myeloma (MM) patients treated upfront with novel agents. NLR was calculated using data obtained from the complete blood count (CBC) at diagnosis and subsequently correlated with PFS and OS. The median NLR was 1.9 (range 0.4-15.9). Higher NLR was independent of international staging system (ISS) stage, plasma cell infiltration or cytogenetics. The 5-year PFS and OS estimates were, respectively, 18.2 and 36.4 % for patients with NLR ≥ 2 versus 25.5 and 66.6 % in patients with NLR < 2. Among younger patients (age <65 years, N = 179), NLR ≥ 2 had a negative prognostic impact on both PFS and OS, in all ISS stages. By combining ISS stage and NLR in a model limited to young patients, we found that 19 % of the patients were classified as very low risk, 70 % standard risk and 11 % very high risk. The 5-year estimates were 39.3, 19.4 and 10.9 % for PFS and 95.8, 50.9 and 23.6 % for OS for very low, standard-risk and very high-risk groups. We found NLR to be a predictor of PFS and OS in MM patients treated upfront with novel agents. NLR can be combined with ISS staging system to identify patients with dismal outcome. However, larger cohorts and prospective studies are needed to use NLR as additional parameter to personalise MM therapy in the era of novel agents.
Asunto(s)
Drogas en Investigación/administración & dosificación , Quimioterapia de Inducción , Linfocitos/patología , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/patología , Neutrófilos/patología , Adulto , Anciano , Anciano de 80 o más Años , Recuento de Células Sanguíneas , Femenino , Humanos , Quimioterapia de Inducción/métodos , Lenalidomida , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Mieloma Múltiple/sangre , Terapia Neoadyuvante , Estadificación de Neoplasias , Estudios Retrospectivos , Medición de Riesgo , Talidomida/administración & dosificación , Talidomida/análogos & derivadosRESUMEN
Ineffective hematopoiesis is a hallmark of myelodysplastic syndromes (MDS). Hematopoietic alterations in MDS patients strictly correlate with microenvironment dysfunctions, eventually affecting also the mesenchymal stromal cell (MSC) compartment. Stromal cells are indeed epigenetically reprogrammed to cooperate with leukemic cells and propagate the disease as "tumor unit"; therefore, changes in MSC epigenetic profile might contribute to the hematopoietic perturbations typical of MDS. Here, we unveil that the histone variant macroH2A1 (mH2A1) regulates the crosstalk between epigenetics and inflammation in MDS-MSCs, potentially affecting their hematopoietic support ability. We show that the mH2A1 splicing isoform mH2A1.1 accumulates in MDS-MSCs, correlating with the expression of the Toll-like receptor 4 (TLR4), an important pro-tumor activator of MSC phenotype associated to a pro-inflammatory behavior. MH2A1.1-TLR4 axis was further investigated in HS-5 stromal cells after ectopic mH2A1.1 overexpression (mH2A1.1-OE). Proteomic data confirmed the activation of a pro-inflammatory signature associated to TLR4 and nuclear factor kappa B (NFkB) activation. Moreover, mH2A1.1-OE proteomic profile identified several upregulated proteins associated to DNA and histones hypermethylation, including S-adenosylhomocysteine hydrolase, a strong inhibitor of DNA methyltransferase and of the methyl donor S-adenosyl-methionine (SAM). HPLC analysis confirmed higher SAM/SAH ratio along with a metabolic reprogramming. Interestingly, an increased LDHA nuclear localization was detected both in mH2A1.1-OE cells and MDS-MSCs, probably depending on MSC inflammatory phenotype. Finally, coculturing healthy mH2A1.1-OE MSCs with CD34+ cells, we found a significant reduction in the number of CD34+ cells, which was reflected in a decreased number of colony forming units (CFU-Cs). These results suggest a key role of mH2A1.1 in driving the crosstalk between epigenetic signaling, inflammation, and cell metabolism networks in MDS-MSCs.
Asunto(s)
Células Madre Mesenquimatosas , Síndromes Mielodisplásicos , Neoplasias , Humanos , ADN/metabolismo , Epigénesis Genética , Histonas/metabolismo , Inflamación/patología , Células Madre Mesenquimatosas/metabolismo , Síndromes Mielodisplásicos/patología , Neoplasias/patología , Proteómica , Receptor Toll-Like 4/metabolismo , Microambiente TumoralRESUMEN
Fish are sensitive to stressful conditions that affect their innate immune systems and increase their susceptibility to diseases. We examined the social stress of paired gilthead seabream (Sparus aurata). Social hierarchies (dominant/subordinate) were characterised by behavioural changes, such as "aggressiveness" and "feeding order"; hierarchical positions were established within an hour of exposure to social stress and remained unchanged for approximately 1 year. To characterise physiological stress, we measured blood plasma levels of cortisol, glucose, and lactate as well as osmolarity and observed that the levels of these stress markers were higher in subordinate individuals than in dominant ones. The discriminant analysis revealed a separation of the subordinate fish groups, and at 15 days, a significant separation among groups was observed. Moreover, diminished phagocytic and respiratory burst activities revealed that social stress appeared to affect the cellular innate immune response of the subordinate specimens. Finally, to examine the effect of cortisol on phagocytosis, peritoneal cavity cells were treated in vitro, and an inhibitory effect was observed.
Asunto(s)
Jerarquia Social , Cavidad Peritoneal/citología , Fagocitosis/inmunología , Estallido Respiratorio/inmunología , Dorada/inmunología , Estrés Fisiológico/inmunología , Estrés Psicológico/inmunología , Animales , Hidrocortisona/farmacología , Fagocitosis/efectos de los fármacosRESUMEN
Hemocytes from the ascidian Ciona intestinalis exert in vitro Ca²+-dependent cytotoxic activity toward mammalian erythrocytes and K562 cells. To examine the lytic mechanism, hemocyte populations were separated (B1-B6 bands) through a Percoll discontinuous density gradient, the hemocyte cytotoxic activity (HCA) and the lytic activity of the hemocyte lysate supernatant (HLS) were assayed. In addition the separated hemocytes were cultured and the cell-free culture medium (CFM) assayed after 3 h culture. Results support that unilocular refractile hemocytes (URGs), enriched in B5, are cytotoxic. The B5-HLS contains lysins and the activity of B5-CFM shows that lysins can be released into a culture medium. The B5 activity was blocked by D-galactose, α-lactose, lactulose, LacNAc, thiodigalactoside (TDG), L-fucose, D-mannose, D-glucose, sphingomyelin (SM), and soluble phospholipase A2 (sPLA2) inhibitors (dibucain, quinacrine). Accordingly, HLS chemico-physical properties (alkaline medium, high thermostability, Ca²+-dependence, trypsin treatment, protease inhibitors) and SEM observations of the affected targets suggested that sPLA2 could be responsible for changes and large alterations of the target cell membrane. An apoptotic activity, as recorded by a caspase 3, 7 assay, was found by treating K562 cells with very diluted HLS. A lytic mechanism involving sPLA2 and lectins promptly released by URGs and morula cells respectively is suggested, whereas target cell membrane SM could be a modulator of the enzyme activity.
Asunto(s)
Ciona intestinalis/inmunología , Membrana Eritrocítica/inmunología , Hemocitos/inmunología , Lectinas Tipo C/inmunología , Fosfolipasas A2/inmunología , beta-Galactosidasa/inmunología , Animales , Caspasas/inmunología , Ciona intestinalis/citología , Ciona intestinalis/enzimología , Pruebas Inmunológicas de Citotoxicidad , Dibucaína/farmacología , Inhibidores Enzimáticos/farmacología , Membrana Eritrocítica/enzimología , Membrana Eritrocítica/ultraestructura , Hemocitos/citología , Hemocitos/enzimología , Humanos , Células K562 , Microscopía Electrónica de Rastreo , Inhibidores de Fosfolipasa A2 , Quinacrina/farmacología , ConejosRESUMEN
BRIT1 (BRCT-repeat inhibitor of hTERT expression), also known as microcephalin (MCPH1), is a crucial gene in the complex cellular machine that is devoted to DNA repair and acts as a regulator of both the intra-S and G2/M checkpoints. The most important role of BRIT1/MCPH1 in the regulation of cell cycle progression appears to be the G2/M checkpoint. The K562 and peripheral blood cells of chronic myeloid leukemia (CML) patients at diagnosis were found to downregulate BRIT1/MCPH1. However, we could not find any correlation between bcr/abl activity and the BRIT1/MCPH1 level. In order to study the genomic instability of CML cells, we evaluated the ability of these cells to arrest mitotic division after exposure to hydroxyurea, a known genotoxic agent. We showed that CML cells continue to proliferate without the activation of the G2/M cell cycle checkpoint arrest or of the apoptotic mechanism. This behavior may predispose the cells to accumulate genomic defects. In conclusion, we found that CML cells have a low BRIT1/MCPH1 level and show a defective G2/M arrest, confirming that these cells have a constitutive genomic instability.
Asunto(s)
Puntos de Control de la Fase G2 del Ciclo Celular , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Actinas/antagonistas & inhibidores , Adulto , Anciano , Proteínas de Ciclo Celular , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Citocalasina B/toxicidad , Citocinesis/efectos de los fármacos , Proteínas del Citoesqueleto , Femenino , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Inestabilidad Genómica , Humanos , Hidroxiurea/antagonistas & inhibidores , Hidroxiurea/toxicidad , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/sangre , Leucocitos/efectos de los fármacos , Leucocitos/metabolismo , Masculino , Persona de Mediana Edad , Mutágenos/toxicidad , Proteínas de Neoplasias/genética , Proteínas del Tejido Nervioso/genética , ARN Mensajero/metabolismoRESUMEN
AIMS: Staphylococcal biofilm-associated infections are resistant to conventional antibiotics. Consequently, new agents are needed to treat them. With this aim, we focused on the effector cells (coelomocytes) of the sea urchin Paracentrotus lividus immune system. METHODS AND RESULTS: We tested the activity of the 5-kDa peptide fraction of the cytosol from coelomocytes (5-CC) against a group of Gram-positive, Gram-negative bacteria and fungi. We determined minimal inhibitory concentrations (MICs) ranging from 253.7 to 15.8 mg ml(-1). We observed an inhibitory activity and antibiofilm properties of 5-CC against staphylococcal biofilms of reference strains Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213. The antimicrobial efficacy of 5-CC against the biofilms of clinical strain Staph. epidermidis 1457 was also tested using live/dead staining in combination with confocal laser scanning microscopy. At a sub-MIC concentration (31 x 7 mg ml(-1)) of 5-CC the formation of young (6-h old) and mature (24-h old) staphylococcal biofilms was inhibited. CONCLUSIONS: The biological activity of 5-CC could be attributed to three peptides belonging to the sequence segment 9-41 of a beta-thymosin of P. lividus. SIGNIFICANCE AND IMPACT OF THE STUDY: The effector cells of P. lividus represent an interesting source of marine invertebrates-derived antimicrobial agents in the development of new strategies to treat staphylococcal biofilms.
Asunto(s)
Antiinfecciosos , Biopelículas/efectos de los fármacos , Paracentrotus/citología , Paracentrotus/metabolismo , Péptidos/farmacología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Animales , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Fraccionamiento Celular , Citosol/química , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía Confocal , Paracentrotus/inmunología , Péptidos/química , Coloración y Etiquetado , Infecciones Estafilocócicas/prevención & control , Timosina/química , Timosina/genéticaRESUMEN
To understand neutrophil impairment in the progression from MGUS through active MM, we investigated the function of mature, high-density neutrophils (HDNs), isolated from peripheral blood. In 7 MM, 3 MGUS and 3 healthy subjects by gene expression profile, we identified a total of 551 upregulated and 343 downregulated genes in MM-HDN, involved in chemokine signaling pathway and FC-gamma receptor mediated phagocytosis conveying in the activation of STAT proteins. In a series of 60 newly diagnosed MM and 30 MGUS patients, by flow-cytometry we found that HDN from MM, and to a lesser extend MGUS, had an up-regulation of the inducible FcγRI (also known as CD64) and a down-regulation of the constitutive FcγRIIIa (also known as CD16) together with a reduced phagocytic activity and oxidative burst, associated to increased immune-suppression that could be reverted by arginase inhibitors in co-culture with lymphocytes. In 43 consecutive newly-diagnosed MM patients, who received first-line treatment based on bortezomib, thalidomide and dexamethasone, high CD64 could identify at diagnosis patients with inferior median overall survival (39.5 versus 86.7 months, p = 0.04). Thus, HDNs are significantly different among healthy, MGUS and MM subjects. In both MGUS and MM neutrophils may play a role in supporting both the increased susceptibility to infection and the immunological dysfunction that leads to tumor progression.
Asunto(s)
Susceptibilidad a Enfermedades/inmunología , Gammopatía Monoclonal de Relevancia Indeterminada/inmunología , Mieloma Múltiple/inmunología , Neutrófilos/inmunología , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/inmunología , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Estudios de Casos y Controles , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Gammopatía Monoclonal de Relevancia Indeterminada/tratamiento farmacológico , Gammopatía Monoclonal de Relevancia Indeterminada/genética , Gammopatía Monoclonal de Relevancia Indeterminada/mortalidad , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Mieloma Múltiple/mortalidad , Neutrófilos/metabolismo , Fagocitosis/genética , Fagocitosis/inmunología , Transducción de Señal/genética , Escape del Tumor/genéticaRESUMEN
Random amplified polymorphic DNA (RAPD) analysis was performed to assess genetic markers of Paracentrotus lividus populations living in stressing environment in the Amvrakikos Gulf (Western Greece, Ionian Sea) where two populations distinguishable in body size, smaller than the open sea ones, were detected. The UPGMA dendrogram, constructed from pairwise. Phi(st) values among population nuclear DNA markers, revealed that the small and medium-sized populations living inside the Amvrakikos presented a lower polymorphism, and form a cluster that shows the genetic distance with normal-sized populations (Ionian and Tyrrhenian Seas) living in open sea. AMOVA analysis indicated a genetic distance among the sea urchin populations from the Tyrrhenian sea and Ionian sea.
Asunto(s)
Paracentrotus/genética , Polimorfismo Genético , Animales , Marcadores Genéticos/genética , Genética de Población/métodos , Grecia , Océanos y Mares , Técnica del ADN Polimorfo Amplificado Aleatorio/métodosRESUMEN
Since glucocorticoids have a role in maintaining the homeostatic status in fish, in the present paper mRNA expression (in situ hybridization) and tissue immunohistochemical localization of a glucocorticoid receptor (DlGR1) in several Dicentrarchus labrax organs are reported. Riboprobe and specific antibodies were prepared by using the DlGR1 that has been previously cloned and sequenced from peritoneal cavity leukocytes. Both mRNA and receptor were identified in head kidney, spleen, gills, intestine, heart and liver tissues. The functional roles of DlGR1 localization are discussed.
Asunto(s)
Lubina/metabolismo , Proteínas de Peces/metabolismo , Receptores de Glucocorticoides/metabolismo , Animales , Lubina/genética , Western Blotting , Proteínas de Peces/genética , Expresión Génica , Inmunohistoquímica , Hibridación in Situ , ARN Mensajero/análisis , Receptores de Glucocorticoides/genéticaRESUMEN
A lectin specific for fucose and galactose was isolated by affinity chromatography on Sepharose CL-6B from the serum of Dicentrarchus labrax. The hemagglutinating activity against rabbit erythrocytes was calcium-independent, and reached its maximum at 37 degrees C. Two protein components were found in the hemagglutinating fractions eluted from the Sepharose column. Only the 34 kDa component (DLL2) eluted from the polyacrylamide gels (SDS-PAGE) showed agglutinating activity against rabbit erythrocytes. SDS-PAGE, in non-reducing conditions, revealed a single 66 kDa protein that reacted with antibodies to the 34 kDa component. Therefore, a dimeric structure stabilized by disulfide bonds can be proposed. The Ca(2+)-independent fucose-binding specificity, a significant amino acid sequence homology of the N-terminal trait, and cross-reaction of eel fucolectin with antibodies to DLL2 suggest that this lectin may be included in the recently identified fucolectin family.
Asunto(s)
Lubina/metabolismo , Lectinas/sangre , Animales , Lubina/sangre , Carbohidratos/farmacología , Centrifugación , Electroforesis en Gel de Poliacrilamida , Pruebas de Hemaglutinación , Immunoblotting , Lectinas/química , Lectinas/aislamiento & purificaciónRESUMEN
The cytotoxic activity against rabbit erythrocytes (RE) and human K562 tumor cells by Styela plicata hemocytes was significantly related to the phenoloxidase (PO) which converts phenols to quinone and initiates the melanogenic pathway. The effector hemocyte population, separated in a Percoll density gradient band, enriched in a granulocyte type named "morula cells", was examined with RE in a hemocyte cytotoxic assay and plaque forming cell assay. Inhibition experiments with the copper chelating agents 1-phenyl-2-thiourea and tropolone, the substrate analogue sodium benzoate and sodium ascorbate support the notion that hemocyte cytotoxic activity is a PO-dependent mechanism. Treatments of hemocytes with the antioxidant enzymes, superoxide dismutase and catalase rule out oxy radicals produced by the melanogenic process as responsible of erythrolysis. Such a result suggests that quinone compounds derived from the melanogenic pathway might be the cytotoxic molecules. The PO-dependent anti-RE activity was also shown in a plaque forming assay in which "morula cells", containing polyphenols and PO, were identified as cytotoxic.
Asunto(s)
Eritrocitos , Hemocitos/fisiología , Monofenol Monooxigenasa/metabolismo , Urocordados/enzimología , Animales , Fraccionamiento Celular , Centrifugación por Gradiente de Densidad , Hemocitos/enzimología , Humanos , Peróxido de Hidrógeno/metabolismo , Óxido Nítrico/metabolismo , Feniltiourea/farmacología , Conejos , Especies Reactivas de Oxígeno/metabolismo , Tropolona/farmacología , Células Tumorales CultivadasRESUMEN
Sea urchin vitellogenin is a high molecular weight glycoprotein, which is the precursor of the major yolk protein present in the unfertilized egg. Vitellogenin processing into the major yolk protein and its further enzymatic cleavage during sea urchin embryonic development, has been extensively described, and the adhesive properties of the processed molecule have been studied. The function of vitellogenin in the adult, where it has been found in the coelomic fluid of both male and female individuals, is still unknown, although its role on promoting the adhesion of embryonic cells has been shown. In this report we describe the detection of vitellogenin in lysates of whole circulating coelomocytes of both male and female sea urchins of the species Paracentrotus lividus. By metrizoic acid gradients we purified total coelomocytes into six subpopulations that were tested for the occurrence of the molecule using vitellogenin-specific polyclonal antibodies. We detected vitellogenin only in the coelomocyte subpopulation called colorless spherule cells, packed in kidney-shaped granules located around the nucleus. We also showed that coelomocytes respond to stress conditions by discharging vitellogenin into the medium. This result together with previous observations on the adhesive properties of the molecule suggest a role for vitellogenin in the clotting phenomenon occurring after host invasion.
Asunto(s)
Erizos de Mar/química , Vitelogeninas/análisis , Animales , Líquidos Corporales/química , Femenino , Masculino , Erizos de Mar/citología , Estrés Mecánico , Fracciones Subcelulares/químicaRESUMEN
Cellular lectins (CLs) of Phallusia mamillata were demonstrated in protein preparations obtained by salt fractionation from hemocytes sonicated in a suitable medium. Since the lectins from the precipitated fraction bind sugars containing D-galactosyl groups, they were purified by affinity chromatography on Sepharose. SDS-PAGE under reducing conditions showed that CLs are formed of two components of apparent MWs approximately 36,900 and 35,090 and thus differ from serum lectins (SLs) (MW about 62,200). The "shrinkage" observed when SLs were examined under nonreducing conditions suggest the presence of intrachain disulphide bonds which can affect the molecular structure of the SLs. CL-SL differences were also revealed by the nonidentity reaction of the immuno-precipitate in immunodiffusion using an anti-SL immune serum. The capacity of hemocytes to form rosettes or clumps with erythrocytes demonstrated that they possess alpha-lactose specific CLs on their surfaces.
Asunto(s)
Células Sanguíneas/análisis , Hemocitos/análisis , Lectinas/aislamiento & purificación , Urocordados/análisis , Animales , Membrana Celular/análisis , Cromatografía de Afinidad , Pruebas de Inhibición de Hemaglutinación , Hemocitos/ultraestructura , Lactosa/metabolismo , Lectinas/inmunología , Peso MolecularRESUMEN
The carbohydrate specificities of Ascidia malaca serum hemagglutinins were determined by hemagglutination inhibition tests. Analysis of agglutinins against rabbit and human A, B, O erythrocytes suggests that the size of the combining site corresponds to a disaccharide with a specificity for saccharides containing a D-galacto configuration (D-melibiose, D-raffinose, D-galactose, alpha-lactose, lactulose, L-arabinose). No anomeric specificity was observed with oligosaccharides. Hydroxyl groups probably involved in hydrogen-bond formation with agglutinin binding site, were identified as carbons C2, C4, C5 and C6 of D-galactose. Absorption experiments showed that two distinct agglutinins with similar sugar specificity ranges were responsible for rabbit and human erythrocyte agglutination. The D-galactose specificity of the agglutinins allowed the isolation, by biospecific affinity chromatography of the serum, of a protein fraction demonstrated by polyacrylamide gel electrophoresis.
Asunto(s)
Metabolismo de los Hidratos de Carbono , Hemaglutininas/aislamiento & purificación , Urocordados/inmunología , Animales , Formación de Anticuerpos , Sitios de Unión , Cromatografía de Afinidad , Eritrocitos/metabolismo , Galactosa/metabolismo , Pruebas de Inhibición de Hemaglutinación , Pruebas de Hemaglutinación , Hemaglutininas/metabolismo , Humanos , Melibiosa/metabolismo , Conejos , Rafinosa/metabolismo , Especificidad de la EspecieRESUMEN
D-galactose specific lectins purified from Ascidia malaca serum contain a major protein component with an apparent molecular weight of about 58,000 daltons, which moves more rapidly under non-reducing conditions. Intramolecular disulfide linkages can explain this behaviour, suggesting a compact protein structure. Membrane lectins have been demonstrated on the surface of about 34% hemocytes by immunofluorescent methods using a rabbit antiserum against the isolated serum lectins. Small, medium and large hemocytes can be positive, as also shown by binding on Sepharose spherules or by rosette formation with sheep and rabbit erythrocytes. Binding is inhibited by the same sugars specific for the serum lectins. Finally, antibodies to the serum lectins specifically agglutinate the hemocytes. This evidence supports the hypothesis that a lectin with the same specificity and certain structural similarities can be found free in the serum and present on hemocyte surfaces.
Asunto(s)
Células Sanguíneas/inmunología , Hemaglutininas/aislamiento & purificación , Hemocitos/inmunología , Urocordados/inmunología , Animales , Sitios de Unión , Unión Competitiva , Membrana Celular/inmunología , Galectinas , Formación de RosetaRESUMEN
The hemolytic activity of coelomic fluid from Holothuria polii is specifically inhibited by sphingomyelin. This phospholipid is the constituent of the membrane which probably interacts with the hemolysin thereby leading to the lysis.
Asunto(s)
Equinodermos/inmunología , Hemólisis/efectos de los fármacos , Pepinos de Mar/inmunología , Animales , Bacterias/inmunología , Líquidos Corporales/inmunología , Colesterol , Proteínas Inactivadoras de Complemento/farmacología , Eritrocitos/inmunología , Fosfolípidos/farmacología , Esfingomielina Fosfodiesterasa/metabolismo , Esfingomielinas/farmacologíaRESUMEN
alpha-Lactose specific lectins are released from Phallusia mamillata hemocytes during short-term cultures. The molecular weight of the subunits, the immunological cross-reaction and the sugar specificity suggest that the released lectins are similar to those isolated from the sonicated hemocytes. Because lectin release appears to take place independently of active protein synthesis, the possibility exists that lectins are pre-formed, stored in hemocytes and released when in vitro conditions stimulate the cells.
Asunto(s)
Hemocitos/metabolismo , Lectinas/metabolismo , Urocordados/metabolismo , Amanitinas/farmacología , Animales , Células Cultivadas , Medios de Cultivo , Cicloheximida/farmacología , Dactinomicina/farmacología , Hemocitos/efectos de los fármacos , Lectinas/aislamiento & purificación , Tasa de Secreción/efectos de los fármacosRESUMEN
Hemocytes from the ascidian, Ciona intestinalis, are capable of lysing erythrocytes in vitro following cell membrane contact. With the aim of examining the mechanism of cytotoxicity, we performed inhibition experiments with lipid components of erythrocyte membranes. Cholesterol is not an inhibitor, whereas, among the phospholipids tested, (sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine) sphingomyelin inhibits the hemolytic activity of hemocytes. However, thin layer chromatography showed that sphingomyelinase activity was not contained in the chloroform-methanol extracts from hemocyte debris. The inhibition capacity of the components ceramide and phosphorylcholine suggests that the entire sphingomyelin molecule is involved in binding cytolysins. The lysin-lipid interactions probably cause changes in erythrocyte membrane permeability, leading to lysis.