RESUMEN
Although the mechanisms by which schistosomes grow and develop in humans are poorly defined, their unique outer tegument layer, which interfaces with host blood, is considered vital to homeostasis of the parasite. Here, we investigated the importance of tegument lipid rafts to the biology of Schistosoma mansoni in the context of host-parasite interactions. We demonstrate the temporal clustering of lipid rafts in response to human epidermal growth factor (EGF) during early somule development, concomitant with the localization of anteriorly orientated EGF receptors (EGFRs) and insulin receptors, mapped using fluorescent EGF/insulin ligand. Methyl-ß-cyclodextrin (MßCD)-mediated depletion of cholesterol from lipid rafts abrogated the EGFR/IR binding at the parasite surface and led to modulation of protein kinase C, extracellular signal-regulated kinase, p38 mitogen-activated protein kinase and Akt signalling pathways within the parasite. Furthermore, MßCD-mediated lipid raft disruption, and blockade of EGFRs using canertinib, profoundly reduced somule motility and survival, and attenuated stem cell proliferation and somule growth and development particularly to the fast-growing liver stage. These findings provide a novel paradigm for schistosome development and vitality in the host, driven through host-parasite interactions at the tegument, that might be exploitable for developing innovative therapeutic approaches to combat human schistosomiasis.
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Factor de Crecimiento Epidérmico , Schistosoma mansoni , Humanos , Animales , Transducción de Señal , Quinasas MAP Reguladas por Señal Extracelular , Proliferación CelularRESUMEN
Adult male and female schistosomes in copula dwell within human blood vessels and lay eggs that cause the major Neglected Tropical Disease human schistosomiasis. How males and females communicate to each other is poorly understood; however, male-female physical interaction is known to be important. Here, we investigate whether excretory-secretory products (ESPs), released into the external milieu by mature Schistosoma mansoni, might induce responses in the opposite sex. We demonstrate that ESPs adhere to the surface of opposite sex worms inducing the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK) pathways, particularly in the parasite tegument. Furthermore, we show that mature worms stimulated signalling in juvenile worms. Strikingly, we demonstrate that ESPs from the opposite sex promote stem cell proliferation, in an ERK- and p38 MAPK-dependent manner, in the tegument and within the testes of males, and the ovaries and vitellaria of females. Hyperkinesia also occurs following opposite sex ESP exposure. Our findings support the hypothesis that male and female schistosomes may communicate over distance to modulate key processes underlying worm development and disease progression, opening unique avenues for schistosomiasis control.
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Hipercinesia , Schistosoma mansoni , Adulto , Humanos , Animales , Femenino , Masculino , Transducción de Señal , Transporte Biológico , Quinasas MAP Reguladas por Señal Extracelular , Proliferación CelularRESUMEN
BACKGROUND: Despite successful control efforts in China over the past 60 years, zoonotic schistosomiasis caused by Schistosoma japonicum remains a threat with transmission ongoing and the risk of localised resurgences prompting calls for a novel integrated control strategy, with an anti-schistosome vaccine as a core element. Anti-schistosome vaccine development and immunisation attempts in non-human mammalian host species, intended to interrupt transmission, and utilising various antigen targets, have yielded mixed success, with some studies highlighting variation in schistosome antigen coding genes (ACGs) as possible confounders of vaccine efficacy. Thus, robust selection of target ACGs, including assessment of their genetic diversity and antigenic variability, is paramount. Tetraspanins (TSPs), a family of tegument-surface antigens in schistosomes, interact directly with the host's immune system and are promising vaccine candidates. Here, for the first time to our knowledge, diversity in S. japonicum TSPs (SjTSPs) and the impact of diversifying selection and sequence variation on immunogenicity in these protiens were evaluated. METHODS: SjTSP sequences, representing parasite populations from seven provinces across China, were gathered by baiting published short-read NGS data and were analysed using in silico methods to measure sequence variation and selection pressures and predict the impact of selection on variation in antigen protein structure, function and antigenic propensity. RESULTS: Here, 27 SjTSPs were identified across three subfamilies, highlighting the diversity of TSPs in S. japonicum. Considerable variation was demonstrated for several SjTSPs between geographical regions/provinces, revealing that episodic, diversifying positive selection pressures promote amino acid variation/variability in the large extracellular loop (LEL) domain of certain SjTSPs. Accumulating polymorphisms in the LEL domain of SjTSP-2, -8 and -23 led to altered structural, functional and antibody binding characteristics, which are predicted to impact antibody recognition and possibly blunt the host's ability to respond to infection. Such changes, therefore, appear to represent a mechanism utilised by S. japonicum to evade the host's immune system. CONCLUSION: Whilst the genetic and antigenic geographic variability observed amongst certain SjTSPs could present challenges to vaccine development, here we demonstrate conservation amongst SjTSP-1, -13 and -14, revealing their likely improved utility as efficacious vaccine candidates. Importantly, our data highlight that robust evaluation of vaccine target variability in natural parasite populations should be a prerequisite for anti-schistosome vaccine development.
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Schistosoma japonicum , Esquistosomiasis Japónica , Esquistosomiasis , Vacunas , Animales , Humanos , Proteínas del Helminto/metabolismo , Tetraspaninas/genética , Tetraspaninas/metabolismo , Esquistosomiasis Japónica/prevención & control , Esquistosomiasis Japónica/parasitología , MamíferosRESUMEN
Echinostoma revolutum (sensu stricto) is a widely distributed member of the Echinostomatidae, a cosmopolitan family of digenetic trematodes with complex life cycles involving a wide range of definitive hosts, particularly aquatic birds. Integrative taxonomic studies, notably those utilising nad1 barcoding, have been essential in discrimination of E. revolutum (s.s.) within the 'Echinostoma revolutum' species complex and investigation of its molecular diversity. No studies, however, have focussed on factors affecting population genetic structure and connectivity of E. revolutum (s.s.) in Eurasia. Here, we used morphology combined with nad1 and cox1 barcoding to determine the occurrence of E. revolutum (s.s.) and its lymnaeid hosts in England for the first time, in addition to other echinostomatid species Echinoparyphium aconiatum, Echinoparyphium recurvatum and Hypoderaeum conoideum. Analysis of genetic diversity in E. revolutum (s.s.) populations across Eurasia demonstrated haplotype sharing and gene flow, probably facilitated by migratory bird hosts. Neutrality and mismatch distribution analyses support possible recent demographic expansion of the Asian population of E. revolutum (s.s.) (nad1 sequences from Bangladesh and Thailand) and stability in European (nad1 sequences from this study, Iceland and continental Europe) and Eurasian (combined data sets from Europe and Asia) populations with evidence of sub-population structure and selection processes. This study provides new molecular evidence for a panmictic population of E. revolutum (s.s.) in Eurasia and phylogeographically expands the nad1 database for identification of echinostomatids.
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Echinostoma , Trematodos , Animales , Echinostoma/genética , Echinostoma/anatomía & histología , Filogenia , Aves , TailandiaRESUMEN
Calcium/calmodulin dependant protein kinase II (CaMKII), an important transducer of Ca2+ signals, orchestrates multiple cellular functions in animals. Here we investigated the importance of CaMKII to Schistosoma mansoni, a blood parasite that causes human schistosomiasis. We demonstrate that phosphorylated (activated) CaMKII is present in cercariae, schistosomula and adult worms, and show that striking activation occurs in the nervous tissue of these parasite life-stages; CaMKII was also activated in the tegument and muscles of adult worms and the vitellaria of females. Exposure of worms to the anti-schistosomal drug praziquantel (PZQ) induced significant CaMKII activation and depletion of CaMKII protein/activation in adult worms resulted in hypokinesia, reduced vitality and death. At medium confidence (global score ≥ 0.40), S. mansoni CaMKII was predicted to interact with 51 proteins, with many containing CaMKII phosphorylation sites and nine mapped to phosphoproteome data including sites within a ryanodine receptor. The CaMKII network was functionally enriched with mitogen-activated protein kinase, Wnt, and notch pathways, and ion-transport and voltage-dependent channel protein domains. Collectively, these data highlight the intricacies of CaMKII signalling in S. mansoni, show CaMKII to be an active player in the PZQ-mediated response of schistosomes and highlight CaMKII as a possible target for the development of novel anti-schistosome therapeutics.
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Antihelmínticos , Schistosoma mansoni , Humanos , Animales , Femenino , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Antihelmínticos/farmacología , Praziquantel/farmacología , Señalización del CalcioRESUMEN
BACKGROUND: Heat shock proteins (HSPs) are evolutionarily conserved proteins, produced by cells in response to hostile environmental conditions, that are vital to organism homeostasis. Here, we undertook the first detailed molecular bioinformatic analysis of these important proteins and mapped their tissue expression in the human parasitic blood fluke, Schistosoma mansoni, one of the causative agents of the neglected tropical disease human schistosomiasis. METHODS: Using bioinformatic tools we classified and phylogenetically analysed HSP family members in schistosomes, and performed transcriptomic, phosphoproteomic, and interactomic analysis of the S. mansoni HSPs. In addition, S. mansoni HSP protein expression was mapped in intact parasites using immunofluorescence. RESULTS: Fifty-five HSPs were identified in S. mansoni across five HSP families; high conservation of HSP sequences were apparent across S. mansoni, Schistosoma haematobium and Schistosoma japonicum, with S. haematobium HSPs showing greater similarity to S. mansoni than those of S. japonicum. For S. mansoni, differential HSP gene expression was evident across the various parasite life stages, supporting varying roles for the HSPs in the different stages, and suggesting that they might confer some degree of protection during life stage transitions. Protein expression patterns of HSPs were visualised in intact S. mansoni cercariae, 3 h and 24 h somules, and adult male and female worms, revealing HSPs in the tegument, cephalic ganglia, tubercles, testes, ovaries as well as other important organs. Analysis of putative HSP protein-protein associations highlighted proteins that are involved in transcription, modification, stability, and ubiquitination; functional enrichment analysis revealed functions for HSP networks in S. mansoni including protein export for HSP 40/70, and FOXO/mTOR signalling for HSP90 networks. Finally, a total of 76 phosphorylation sites were discovered within 17 of the 55 HSPs, with 30 phosphorylation sites being conserved with those of human HSPs, highlighting their likely core functional significance. CONCLUSIONS: This analysis highlights the fascinating biology of S. mansoni HSPs and their likely importance to schistosome function, offering a valuable and novel framework for future physiological investigations into the roles of HSPs in schistosomes, particularly in the context of survival in the host and with the aim of developing novel anti-schistosome therapeutics.
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Parásitos , Schistosoma mansoni , Animales , Femenino , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Humanos , Masculino , Schistosoma haematobium , Schistosoma mansoni/fisiología , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Cervical cancer is one of the most frequently diagnosed cancers in women worldwide. While cervical cancer is caused by human papillomavirus (HPV), not all females infected with HPV develop the disease, suggesting that other factors might facilitate its progression. Growing evidence supports the involvement of the fibroblast growth factor receptor (FGFR) axis in several cancers, including gynecological. However, for cervical cancer, the molecular mechanisms that underpin the disease remain poorly understood, including the role of FGFR signaling. The aim of this study was to investigate FGF(R) signaling in cervical cancer through bioinformatic analysis of cell line and patient data and through detailed expression profiling, manipulation of the FGFR axis, and downstream phenotypic analysis in cell lines (HeLa, SiHa, and CaSki). Expression (protein and mRNA) analysis demonstrated that FGFR1b/c, FGFR2b/c, FGFR4, FGF2, FGF4, and FGF7 were expressed in all three lines. Interestingly, FGFR1 and 2 localized to the nucleus, supporting that nuclear FGFRs could act as transcription factors. Importantly, 2D and 3D cell cultures demonstrated that FGFR activation can facilitate cell functions correlated with invasive disease. Collectively, this study supports an association between FGFR signaling and cervical cancer progression, laying the foundations for the development of therapeutic approaches targeting FGFR in this disease.
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Factores de Crecimiento de Fibroblastos , Receptores de Factores de Crecimiento de Fibroblastos , Neoplasias del Cuello Uterino , Femenino , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/metabolismo , Humanos , Infecciones por Papillomavirus , Procesamiento Proteico-Postraduccional , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos/genética , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Transducción de Señal , Neoplasias del Cuello Uterino/genéticaRESUMEN
Schistosomules of the human parasite Schistosoma mansoni are vital for research focusing on the fundamental functional/developmental biology of schistosomes and many anti-schistosomal drug discovery programmes. Through the further evaluation and validation of a recently tested media, HybridoMed Diff 1000 (HM), for the cell-free culture of juvenile schistosomules, we show that while Basch medium was superior to HM for the survival/development of schistosomules, HM represents a viable and attractive alternative for somule culture, particularly to the early liver stage. Adoption of HM for schistosomule culture could facilitate more standardised approaches, which for drug screening should enable improved multi-centre target-hit evaluation.
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Técnicas de Cultivo de Célula , Schistosoma mansoni , Animales , Descubrimiento de Drogas , Evaluación Preclínica de Medicamentos , HumanosRESUMEN
When scanning across a scene, luminance can vary by up to 100,000-to-1 (high dynamic range, HDR), requiring multiple normalizing mechanisms spanning from the retina to the cortex to support visual acuity and recognition. Vision models based on standard dynamic range (SDR) luminance contrast ratios below 100-to-1 have limited ability to generalize to real-world scenes with HDR luminance. To characterize how orientation and luminance are linked in brain mechanisms for luminance normalization, we measured orientation discrimination of Gabor targets under HDR luminance dynamics. We report a novel phenomenon, that abrupt 10- to 100-fold darkening engages contextual facilitation, distorting the apparent orientation of a high-contrast central target. Surprisingly, facilitation was influenced by grouping by luminance similarity, as well as by the degree of luminance variability in the surround. These results challenge vision models based solely on activity normalization and raise new questions that will lead to models that perform better in real-world scenes.
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Sensibilidad de Contraste/fisiología , Adaptación a la Oscuridad/fisiología , Luz , Orientación Espacial/fisiología , Adolescente , Adulto , Anciano , Movimientos Oculares/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reconocimiento en Psicología , Agudeza Visual/fisiología , Adulto JovenRESUMEN
BACKGROUND: Real-world illumination challenges both autonomous sensing and displays, because scene luminance can vary by up to 109-to-1, whereas vision models have limited ability to generalize beyond 100-to-1 luminance contrast. Brain mechanisms automatically normalize the visual input based on feature context, but they remain poorly understood because of the limitations of commercially available displays. NEW METHOD: Here, we describe procedures for setup, calibration, and precision check of an HDR display system, based on a JVC DLA-RS600U reference projector, with over 100,000-to-1 luminance dynamic range (636-0.006055â¯cd/m2), pseudo 11 bit grayscale precision, and 3â¯ms temporal precision in the MATLAB/Psychtoolbox software environment. The setup is synchronized with electroencephalography (EEG) and infrared eye-tracking measurements. RESULTS: We show display metrics including light scatter versus average display luminance (ADL), spatial uniformity, and spatial uniformity at high spatial frequency. We also show a luminance normalization phenomenon, contextual facilitation of a high contrast target, whose discovery required HDR display. COMPARISON WITH EXISTING METHODS: This system provides 100-fold greater dynamic range than standard 1000-to-1 contrast displays and increases the number of gray levels from 256 or 1024 (8 or 10 bits) to 2048 (pseudo 11 bits), enabling the study of mesopic-to-photopic vision, at the expense of spatial non-uniformities. CONCLUSIONS: This HDR research capability opens new questions of how visual perception is resilient to real-world luminance dynamics and will lead to improved visual modeling of dense urban and forest environments and of mixed indoor-outdoor environments such as cockpits and augmented reality. Our display metrics code can be found at https://github.com/USArmyResearchLab/ARL-Display-Metrics-and-Average-Display-Luminance.
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Visión de Colores , Programas Informáticos , Iluminación , Estimulación Luminosa , Percepción VisualRESUMEN
Although helminth parasites cause enormous suffering worldwide we know little of how protein phosphorylation, one of the most important post-translational modifications used for molecular signalling, regulates their homeostasis and function. This is particularly the case for schistosomes. Herein, we report a deep phosphoproteome exploration of adult Schistosoma mansoni, providing one of the richest phosphoprotein resources for any parasite so far, and employ the data to build the first parasite-specific kinomic array. Complementary phosphopeptide enrichment strategies were used to detect 15,844 unique phosphopeptides mapping to 3,176 proteins. The phosphoproteins were predicted to be involved in a wide range of biological processes and phosphoprotein interactome analysis revealed 55 highly interconnected clusters including those enriched with ribosome, proteasome, phagosome, spliceosome, glycolysis, and signalling proteins. 93 distinct phosphorylation motifs were identified, with 67 providing a 'footprint' of protein kinase activity; CaMKII, PKA and CK1/2 were highly represented supporting their central importance to schistosome function. Within the kinome, 808 phosphorylation sites were matched to 136 protein kinases, and 68 sites within 37 activation loops were discovered. Analysis of putative protein kinase-phosphoprotein interactions revealed canonical networks but also novel interactions between signalling partners. Kinomic array analysis of male and female adult worm extracts revealed high phosphorylation of transformation:transcription domain associated protein by both sexes, and CDK and AMPK peptides by females. Moreover, eight peptides including protein phosphatase 2C gamma, Akt, Rho2 GTPase, SmTK4, and the insulin receptor were more highly phosphorylated by female extracts, highlighting their possible importance to female worm function. We envision that these findings, tools and methodology will help drive new research into the functional biology of schistosomes and other helminth parasites, and support efforts to develop new therapeutics for their control.
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Proteínas del Helminto/metabolismo , Fosfoproteínas/metabolismo , Proteoma/análisis , Schistosoma mansoni/metabolismo , Secuencia de Aminoácidos , Animales , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Femenino , Proteínas del Helminto/genética , Masculino , Péptidos/metabolismo , Fosforilación , Mapas de Interacción de Proteínas , Proteínas Quinasas , Procesamiento Proteico-Postraduccional , Schistosoma mansoni/genética , Transducción de SeñalRESUMEN
Schistosoma spindale and Schistosoma indicum are ruminant-infecting trematodes of the Schistosoma indicum group that are widespread across Southeast Asia. Though neglected, these parasites can cause major pathology and mortality to livestock leading to significant welfare and socio-economic issues, predominantly amongst poor subsistence farmers and their families. Here we used mitogenomic analysis to determine the relationships between these two sympatric species of schistosome and to characterise S. spindale diversity in order to identify possible cryptic speciation. The mitochondrial genomes of S. spindale and S. indicum were assembled and genetic analyses revealed high levels of diversity within the S. indicum group. Evidence of functional changes in mitochondrial genes indicated adaptation to environmental change associated with speciation events in S. spindale around 2.5 million years ago. We discuss our results in terms of their theoretical and applied implications.
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Evolución Molecular , Genoma de los Helmintos , Genoma Mitocondrial , Schistosoma/genética , Animales , Especiación Genética , Schistosoma/clasificación , SimpatríaRESUMEN
Monoclonal antibody (mAb) technology is an excellent tool for the discovery of overexpressed cell surface tumour antigens and the development of targeting agents. Here, we report the development of two novel mAbs against CFPAC-1 human pancreatic cancer cells. Using ELISA, flow cytometry, immunoprecipitation, mass spectrometry, Western blot and immunohistochemistry, we found that the target antigens recognised by the two novel mAbs KU44.22B and KU44.13A, are integrin α3 and CD26 respectively, with high levels of expression in human pancreatic and other cancer cell lines and human pancreatic cancer tissue microarrays. Treatment with naked anti-CD26 mAb KU44.13A did not have any effect on the growth and migration of cancer cells nor did it induce receptor downregulation. In contrast, treatment with anti-integrin α3 mAb KU44.22B inhibited growth in vitro of Capan-2 cells, increased migration of BxPC-3 and CFPAC-1 cells and induced antibody internalisation. Both novel mAbs are capable of detecting their target antigens by immunohistochemistry but not by Western blot. These antibodies are excellent tools for studying the role of integrin α3 and CD26 in the complex biology of pancreatic cancer, their prognostic and predictive values and the therapeutic potential of their humanised and/or conjugated versions in patients whose tumours overexpress integrin α3 or CD26.
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Anticuerpos Monoclonales/inmunología , Dipeptidil Peptidasa 4/inmunología , Dipeptidil Peptidasa 4/metabolismo , Regulación Neoplásica de la Expresión Génica , Integrina alfa3/inmunología , Integrina alfa3/metabolismo , Neoplasias Pancreáticas/metabolismo , Animales , Línea Celular Tumoral , Progresión de la Enfermedad , Humanos , Ratones , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/patologíaRESUMEN
Lymnaea stagnalis is a common freshwater gastropod. Importantly, the snail serves as the intermediate host for more than one hundred species of digenetic trematodes, including the avian schistosome Trichobilharzia szidati, a causative agent of cercarial dermatitis in humans. Infection of L. stagnalis by T. szidati initiates a dynamic confrontation between the host and the parasite that culminates in immunocompatibility ensuring survival and development of larvae. Unfortunately, the molecular mechanisms determining this immunocompatibility remain poorly characterised. By employing a variety of immune elicitors, including chemical compounds, PAMPs and bacteria, research in the last two decades has elucidated some of the molecular processes that regulate the snail internal defence response such as haemocyte signalling pathways. These discoveries provide a framework for future studies of molecular interactions between T. szidati and L. stagnalis to help elucidate factors and mechanisms enabling transmission of schistosome parasites. Moreover, support from recently available next generation sequence data and CRISPR-enabled functional genomics should further enable L. stagnalis as an important model for comparative immunology and contribute to a more comprehensive understanding of immune functions in gastropod molluscs.
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Lymnaea/inmunología , Lymnaea/parasitología , Schistosomatidae/fisiología , Animales , Hemocitos/inmunología , Hemocitos/parasitología , Interacciones Huésped-Parásitos/inmunología , Humanos , Inmunomodulación , Estadios del Ciclo de Vida , Transducción de Señal/inmunología , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/transmisiónRESUMEN
When adult schistosome worm pairs are transferred from experimental hosts to in vitro culture they cease producing viable eggs within a few days. Female worms in unisexual infections fail to mature, and when mature adult females are separated from male partners they regress sexually. Worms cultured from the larval stage are also permanently reproductively defective. The cytokine transforming growth factor beta derived from the mammalian host is considered important in stimulating schistosome female worm maturation and maintenance of fecundity. The means by which schistosomes acquire TGF-ß have not been elucidated, but direct uptake in vivo seems unlikely as the concentration of free, biologically active cytokine in host blood is very low. Here we review the complexities of schistosome development and male-female interactions, and we speculate about two possibilities on how worms obtain the TGF-ß they are assumed to need: (i) worms may have mechanisms to free active cytokine from the latency-inducing complex of proteins in which it is associated, and/or (ii) they may obtain the cytokine from alpha 2-macroglobulin, a blood-borne protease inhibitor to which TGF-ß can bind. These ideas are experimentally testable.
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Schistosoma/fisiología , Factor de Crecimiento Transformador beta/metabolismo , Animales , Femenino , Fertilidad/fisiología , Interacciones Huésped-Parásitos , Masculino , Preferencia en el Apareamiento Animal/fisiología , Ratones , Oviposición/fisiología , alfa 2-Macroglobulinas Asociadas al Embarazo/metabolismo , alfa 2-Macroglobulinas Asociadas al Embarazo/fisiología , Conejos , Schistosoma/inmunología , Maduración Sexual/fisiologíaRESUMEN
Pancreatic cancer is one of the most aggressive and lethal types of cancer, and more effective therapeutic agents are urgently needed. Overexpressed cell surface antigens are ideal targets for therapy with monoclonal antibody (mAb)-based drugs, but none have been approved for the treatment of pancreatic cancer. Here, we report development of two novel mouse mAbs, KU42.33C and KU43.13A, against the human pancreatic cancer cell line BxPC-3. Using ELISA, flow cytometry, competitive assay and immunoprecipitation followed by mass spectrometry, we discovered that these two mAbs target two distinct epitopes on the external domain of CD109 that are overexpressed by varying amounts in human pancreatic cancer cell lines. Treatment with these two naked antibodies alone did not affect tumour cell growth or migration in vitro. Of the two mAbs, only KU42.33C was useful in determining the expression of CD109 in tumour cells by Western blot and immunohistochemistry. Interestingly, immunohistochemistry of human pancreatic carcinoma tissue arrays with mAb KU42.33C showed that 94% of the 65 human pancreatic adenocarcinoma cases were CD109 positive, with no expression in normal pancreatic tissues. Our results suggest that these two novel mAbs are excellent tools for determining the expression level of CD109 in the tumour specimens and sera of patients with a wide range of cancers, in particular pancreatic cancer, and for investigating its diagnostic, prognostic and predictive value. Further research is warranted and should aim to unravel the therapeutic potential of the humanised forms or conjugated versions of such antibodies in patients whose tumours overexpress CD109 antigen.
RESUMEN
Background: In Schistosoma mansoni, the facilitated glucose transporter SGTP4, which is expressed uniquely in the apical surface tegumental membranes of the parasite, imports glucose from host blood to support its growth, development, and reproduction. However, the molecular mechanisms that underpin glucose uptake in this blood fluke are not understood. Methods: In this study we employed techniques including Western blotting, immunolocalization, confocal laser scanning microscopy, pharmacological assays, and RNA interference to functionally characterize and map activated Akt in S mansoni. Results: We find that Akt, which could be activated by host insulin and l-arginine, was active in the tegument layer of both schistosomules and adult worms. Blockade of Akt attenuated the expression and evolution of SGTP4 at the surface of the host-invading larval parasite life-stage, and suppressed SGTP4 expression at the tegument in adults; concomitant glucose uptake by the parasite was also attenuated in both scenarios. Conclusions: These findings shed light on crucial mechanistic signaling processes that underpin the energetics of glucose uptake in schistosomes, which may open up novel avenues for antischistosome drug development.
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Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Glucosa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Schistosoma mansoni/metabolismo , Transducción de Señal , Animales , Femenino , MasculinoRESUMEN
The discovery that mammalian neutrophils generate extracellular chromatin fibers that entrap/kill bacteria supported a new paradigm for innate immunity in animals. Similar findings in other models across diverse taxa have led to the hypothesis that the phenomenon is ancient and evolutionary conserved. Here, using a variety of synthetic (e.g. peptidoglycan) and biological (e.g. trematode larvae) components to investigate extracellular trap-like (ET-like) fiber production in vitro by haemocytes of Lymnaea stagnalis, Radix lagotis and Planorbarius corneus snails, ET-like fibers were rarely observed. We suggest, therefore, that ET-like fibers play a marginal role in defence of these snail species and thus the fiber production may not be a critical process underpinning immunity in all invertebrate species.
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Trampas Extracelulares , Hemocitos/inmunología , Neutrófilos/inmunología , Caracoles/inmunología , Trematodos/fisiología , Infecciones por Trematodos/inmunología , Animales , Antígenos Helmínticos/inmunología , Evolución Biológica , Células Cultivadas , Inmunidad Innata , Larva , Mamíferos/inmunología , Peptidoglicano/inmunologíaRESUMEN
Lecithodendrium linstowi is one of the most prevalent and abundant trematodes of bats, but the larval stages and intermediate hosts have not been identified. We present the first molecular and morphological characterization of the cercariae of L. linstowi based on a phylogenetic analysis of partial fragments of LSU and ITS2 rDNA. The first intermediate host was incriminated as Radix balthica by DNA barcoding using cox1 and ITS2 sequences, although the snail morphologically resembled Radix peregra, emphasizing the requirement for molecular identification of lymnaeids as important intermediate hosts of medical and veterinary impact. The application of molecular data in this study has enabled linkage of life cycle stages and accurate incrimination of the first intermediate host.