The Experts below are selected from a list of 2424 Experts worldwide ranked by ideXlab platform
Alex Loukas - One of the best experts on this subject based on the ideXlab platform.
-
vaccination with schistosoma mansoni cholinesterases reduces the parasite burden and egg viability in a mouse model of Schistosomiasis
Vaccine, 2020Co-Authors: Bemnet Amare Tedla, Alex Loukas, Darren Pickering, Luke Becker, Mark S. PearsonAbstract:Schistosomiasis is a neglected tropical disease caused by parasitic blood flukes of the genus Schistosoma, which kills 300,000 people every year in developing countries, and there is no Vaccine. Recently, we have shown that cholinesterases (ChEs)—enzymes that regulate neurotransmission—from Schistosoma mansoni are expressed on the outer tegument surface and present in the excretory/secretory products of larval schistosomula and adult worms, and are essential for parasite survival in the definitive host, highlighting their utility as potential Schistosomiasis Vaccine targets. When treated in vitro with anti-schistosome cholinesterase (SmChE) IgG, both schistosomula and adult worms displayed significantly decreased ChE activity, which eventually resulted in parasite death. Vaccination with individual SmChEs, or a combination of all three SmChEs, significantly reduced worm burdens in two independent trials compared to controls. Average adult worm numbers and liver egg burdens were significantly decreased for all vaccinated mice across both trials, with values of 29–39% and 13–46%, respectively, except for those vaccinated with SmAChE1 in trial 1. Egg viability, as determined by egg hatching from liver homogenates, was significantly reduced in the groups vaccinated with the SmChE cocktail (40%) and SmAChE2 (46%). Furthermore, surviving worms from each vaccinated group were significantly stunted and depleted of glycogen stores, compared to controls. These results suggest that SmChEs could be incorporated into a Vaccine against Schistosomiasis to reduce the pathology and transmission of this debilitating disease.
-
vaccination with schistosoma mansoni cholinesterases reduces parasite burden and egg viability in a mouse model of Schistosomiasis
bioRxiv, 2020Co-Authors: Mark S. Pearson, Darren Pickering, Bemnet Amare Tedla, Luke Becker, Alex LoukasAbstract:Schistosomiasis is a neglected tropical disease which kills 300,000 people every year in developing countries and there is no Vaccine. Recently, we have shown that cholinesterases (ChEs) - enzymes that regulate neurotransmission - from Schistosoma mansoni are expressed on the tegument and present in the excretory/secretory products of schistosomula and adult worms, and are essential for parasite survival in the definitive host, highlighting their utility as potential Schistosomiasis Vaccine targets. When treated in vitro with anti- Sm ChE IgG, both schistosomula and adult worms displayed significantly decreased ChE activity, which eventually resulted in parasite death. Vaccination with individual SmChEs, or a combination of all three SmChEs, significantly reduced worm burdens in two independent trials compared to controls. Liver egg burdens were significantly decreased for all vaccinated mice across both trials (13% - 46%) except for those vaccinated with Sm AChE1 in trial 1. Egg viability, as determined by egg hatching from liver homogenates, was significantly reduced in the groups vaccinated with the Sm ChE cocktail (40%) and Sm AChE2 (46%). Further, surviving worms from each vaccinated group were significantly stunted and depleted of glycogen stores, compared to controls. These results suggest that Sm ChEs could be incorporated into a Vaccine against Schistosomiasis to reduce the pathology and transmission of this debilitating disease.
-
lipid core peptide targeting the cathepsin d hemoglobinase of schistosoma mansoni as a component of a Schistosomiasis Vaccine
Human Vaccines & Immunotherapeutics, 2014Co-Authors: Annette M Dougall, Istvan Toth, Mariusz Skwarczynski, Makan Khoshnejad, Saranya Chandrudu, Norelle L Daly, Alex LoukasAbstract:The self-adjuvanting lipid core peptide (LCP) system offers a safe alternative Vaccine delivery strategy, eliminating the need for additional adjuvants such as CpG Alum. In this study, we adopted the LCP as a scaffold for an epitope located on the surface of the cathepsin D hemoglobinase (Sm-CatD) of the human blood fluke Schistosoma mansoni. Sm-CatD plays a pivotal role in digestion of the fluke’s bloodmeal and has been shown to be efficacious as a subunit Vaccine in a murine model of human Schistosomiasis. Using molecular modeling we showed that S. mansoni cathepsin D possesses a predicted surface exposed α-helix (A263K) that corresponds to an immunodominant helix and target of enzyme–neutralizing antibodies against Necator americanus APR-1 (Na-APR-1), the orthologous protease and Vaccine antigen from blood-feeding hookworms. The A263K epitope was engineered as two peptide variants, one of which was flanked at both termini with a coil maintaining sequence, thereby promoting the helical characteristics o...
-
REVIEW Open Access
2013Co-Authors: Patrick Driguez, Phillip L Felgner, Alex Loukas, Denise L. Doolan, Donald P McmanusAbstract:The recent publication of the Schistosoma japonicum and S. mansoni genomes has expanded greatly the opportunities for post-genomic Schistosomiasis Vaccine research. Immunomics protein microarrays provide an excellent application of this new schistosome sequence information, having been utilised successfully for Vaccine antigen discovery with a range of bacterial and viral pathogens, and malaria. Accordingly, we have designed and manufactured a Schistosoma immunomics protein microarray as a Vaccine discovery tool. The microarray protein selection combined previously published data and in silico screening of available sequences for potential immunogens based on protein location, homology to known protective antigens, and high specificity to schistosome species. Following cloning, selected sequences were expressed cell-free and contact-printed onto nitrocellulose microarrays. The reactivity of microarray proteins with antisera from Schistosomiasisexposed/resistant animals or human patients can be measured with labelled secondary antibodies and a laser microarray scanner; highly reactive proteins can be further assessed as putative Vaccines. This highly innovative technology has the potential to transform Vaccine research for Schistosomiasis and other parasitic diseases of humans and animals. Revie
-
Enhanced Protective Efficacy of a Chimeric Form of the Schistosomiasis Vaccine Antigen Sm-TSP-2
2013Co-Authors: Mark S. Pearson, Annette M Dougall, Darren A. Pickering, Henry J. Mcsorley, Jeffrey M. Bethony, Leon Tribolet, Peter J. Hotez, Alex LoukasAbstract:The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund’s adjuvants, has been shown to be an efficacious Vaccine against murine Schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG1 and IgG3 from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubility enhancing fusion partner. We also expressed in E. coli a chimera called Sm-TSP-2/5B, which consisted of Sm-TSP-2 fused to the immunogenic 5B region of the hookworm aspartic protease and Vaccine antigen, Na-APR-1. Sm-TSP-2 formulated with alum/CpG showed significant reductions in adult worm and liver egg burdens in two separate murine Schistosomiasis challenge studies. Sm-TSP-2/5B afforded significantly greater protection than Sm-TSP-2 alone when both antigens were formulated with alum/CpG. The enhanced protection obtained with the chimeric fusion protein was associated with increased production of anti-Sm-TSP-2 antibodies and IL-4, IL-10 and IFN-c from spleen cells of vaccinated animals. Sera from 666 individuals from Brazil who were infected with S. mansoni were screened for potentially deleterious IgE responses to Sm-TSP-2. Anti-Sm-TSP-2 IgE to this protein was not detected (also shown previously for Na-APR-1), suggesting that the chimeric antigen Sm-TSP-2/5B could be used to safely and effectively vaccinate people in areas wher
Malcolm K Jones - One of the best experts on this subject based on the ideXlab platform.
-
molecular characterization of a tetraspanin from the human liver fluke opisthorchis viverrini
PLOS Neglected Tropical Diseases, 2012Co-Authors: Supawadee Piratae, Banchob Sripa, Smarn Tesana, Malcolm K Jones, Erica Lovas, Veerachai Eursitthichai, Sirikanda ThanasuwanAbstract:Background The human liver fluke, Opisthorchis viverrini, is designated as a group 1 carcinogen, and is the major risk factor for cholangiocarcinoma in endemic countries throughout Southeast Asia. Proteins in the excretory-secretory products and tegumental surface membranes of the fluke have been proposed to play pivotal roles in parasite survival in the host, and subsequent pathogenesis. These macromolecules are therefore valid targets for the development of Vaccines and new drugs to control the infection. Tetraspanins (TSP) are prominent components of the tegument of blood flukes where they are essential for tegument formation, are directly exposed to the immune system, and are major targets for a Schistosomiasis Vaccine. We propose that similar molecules in the surface membranes of O. viverrini are integral to tegument biogenesis and will be efficacious Vaccine antigens. Methodology/Principal Findings The cDNA sequence encoding O. viverrini tetraspanin-1 (Ov-TSP-1) was identified and cloned. The Ov-tsp-1gene was isolated from a cDNA library. Ov-tsp-1 mRNA was expressed most highly in metacercariae and eggs, and to a lesser extent in juvenile and adult worms. Immunolocalization with adult flukes confirmed that Ov-TSP-1 was expressed in the tegument and eggs in utero. Western blot analysis of rOv-TSP-1 probed with sera from O. viverrini-infected humans and hamsters indicated that both hosts raise antibody responses against the native TSP. Using RNA interference we silenced the expression level of Ov-tsp-1 mRNA in adult flukes by up to 72% by 10 days after delivery of dsRNA. Ultrastructural morphology of adult worms treated with Ov-tsp-1 dsRNA displayed a distinctly vacuolated and thinner tegument compared with controls. Conclusions/Significance This is the first report of a tetraspanin from the tegument of a liver fluke. Our data imply that tetraspanins play important structural roles in the development of the tegument in the adult fluke. Potential uses of O. viverrini tetraspanins as novel interventions are discussed.
-
the secreted and surface proteomes of the adult stage of the carcinogenic human liver fluke opisthorchis viverrini
Proteomics, 2010Co-Authors: Jason Mulvenna, Banchob Sripa, Malcolm K Jones, Paul J Brindley, Jeffrey J Gorman, Michelle L Colgrave, Alun Jones, Sujeevi Nawaratna, Thewarach LahaAbstract:Infection with the human liver fluke, Opisthorchis viverrini, is a serious public health problem in Thailand, Laos and nearby locations in Southeast Asia. Both experimental and epidemiological evidence strongly implicate liver fluke infection in the etiology of one of the liver cancer subtypes, cholangiocarcinoma (CCA). To identify parasite proteins critical for liver fluke survival and the etiology of CCA, OFFGEL electrophoresis and multiple reaction monitoring were employed to characterize 300 parasite proteins from the O. viverrini excretory/secretory products and, utilizing selective labeling and sequential solubilization, from the host-exposed tegument. The excretory/secretory included a complex mixture of proteins that have been associated with cancers, including proteases of different mechanistic classes and orthologues of mammalian growth factors and anti-apoptotic proteins. Also identified was a cysteine protease inhibitor which, in other helminth pathogens, induces nitric oxide production by macrophages, and, hence may contribute to malignant transformation of inflamed cells. More than 160 tegumental proteins were identified using sequential solubilization of isolated teguments, and a subset of these was localized to the surface membrane of the tegument by labeling living flukes with biotin and confirming surface localization with fluorescence microscopy. These included annexins, which are potential immuno-modulators, and orthologues of the Schistosomiasis Vaccine antigens Sm29 and tetraspanin-2. Novel roles in pathogenesis were suggested for the tegument-host interface since more than ten surface proteins had no homologues in the public databases. The O. viverrini proteins identified here provide an extensive catalogue of novel leads for research on the pathogenesis of opisthorchiasis and the development of novel interventions for this disease and CCA, as well as providing a scaffold for sequencing the genome of this fluke.
Mark S. Pearson - One of the best experts on this subject based on the ideXlab platform.
-
vaccination with schistosoma mansoni cholinesterases reduces the parasite burden and egg viability in a mouse model of Schistosomiasis
Vaccine, 2020Co-Authors: Bemnet Amare Tedla, Alex Loukas, Darren Pickering, Luke Becker, Mark S. PearsonAbstract:Schistosomiasis is a neglected tropical disease caused by parasitic blood flukes of the genus Schistosoma, which kills 300,000 people every year in developing countries, and there is no Vaccine. Recently, we have shown that cholinesterases (ChEs)—enzymes that regulate neurotransmission—from Schistosoma mansoni are expressed on the outer tegument surface and present in the excretory/secretory products of larval schistosomula and adult worms, and are essential for parasite survival in the definitive host, highlighting their utility as potential Schistosomiasis Vaccine targets. When treated in vitro with anti-schistosome cholinesterase (SmChE) IgG, both schistosomula and adult worms displayed significantly decreased ChE activity, which eventually resulted in parasite death. Vaccination with individual SmChEs, or a combination of all three SmChEs, significantly reduced worm burdens in two independent trials compared to controls. Average adult worm numbers and liver egg burdens were significantly decreased for all vaccinated mice across both trials, with values of 29–39% and 13–46%, respectively, except for those vaccinated with SmAChE1 in trial 1. Egg viability, as determined by egg hatching from liver homogenates, was significantly reduced in the groups vaccinated with the SmChE cocktail (40%) and SmAChE2 (46%). Furthermore, surviving worms from each vaccinated group were significantly stunted and depleted of glycogen stores, compared to controls. These results suggest that SmChEs could be incorporated into a Vaccine against Schistosomiasis to reduce the pathology and transmission of this debilitating disease.
-
vaccination with schistosoma mansoni cholinesterases reduces parasite burden and egg viability in a mouse model of Schistosomiasis
bioRxiv, 2020Co-Authors: Mark S. Pearson, Darren Pickering, Bemnet Amare Tedla, Luke Becker, Alex LoukasAbstract:Schistosomiasis is a neglected tropical disease which kills 300,000 people every year in developing countries and there is no Vaccine. Recently, we have shown that cholinesterases (ChEs) - enzymes that regulate neurotransmission - from Schistosoma mansoni are expressed on the tegument and present in the excretory/secretory products of schistosomula and adult worms, and are essential for parasite survival in the definitive host, highlighting their utility as potential Schistosomiasis Vaccine targets. When treated in vitro with anti- Sm ChE IgG, both schistosomula and adult worms displayed significantly decreased ChE activity, which eventually resulted in parasite death. Vaccination with individual SmChEs, or a combination of all three SmChEs, significantly reduced worm burdens in two independent trials compared to controls. Liver egg burdens were significantly decreased for all vaccinated mice across both trials (13% - 46%) except for those vaccinated with Sm AChE1 in trial 1. Egg viability, as determined by egg hatching from liver homogenates, was significantly reduced in the groups vaccinated with the Sm ChE cocktail (40%) and Sm AChE2 (46%). Further, surviving worms from each vaccinated group were significantly stunted and depleted of glycogen stores, compared to controls. These results suggest that Sm ChEs could be incorporated into a Vaccine against Schistosomiasis to reduce the pathology and transmission of this debilitating disease.
-
An Immunomics Approach to Schistosome Antigen Discovery: Antibody Signatures of Naturally Resistant and Chronically Infected Individuals from Endemic Areas
2016Co-Authors: Soraya Gaze, Patrick Driguez, Donald P Mcmanus, Denise L. Doolan, Mark S. Pearson, Tiago Mendes, Angela Trieu, Geoffrey N. Gobert, Maria Victoria Periago, Rodrigo Correa OliveiraAbstract:Schistosomiasis is a neglected tropical disease that is responsible for almost 300,000 deaths annually. Mass drug administration (MDA) is used worldwide for the control of Schistosomiasis, but chemotherapy fails to prevent reinfection with schistosomes, so MDA alone is not sufficient to eliminate the disease, and a prophylactic Vaccine is required. Herein, we take advantage of recent advances in systems biology and longitudinal studies in Schistosomiasis endemic areas in Brazil to pilot an immunomics approach to the discovery of Schistosomiasis Vaccine antigens. We selected mostly surface-derived proteins, produced them using an in vitro rapid translation system and then printed them to generate the first protein microarray for a multi-cellular pathogen. Using well-established Brazilian cohorts of putatively resistant (PR) and chronically infected (CI) individuals stratified by the intensity of their S. mansoni infection, we probed arrays for IgG subclass and IgE responses to these antigens to detect antibody signatures that were reflective of protective vs. non-protective immun
-
an immunomics approach to schistosome antigen discovery antibody signatures of naturally resistant and chronically infected individuals from endemic areas
PLOS Pathogens, 2014Co-Authors: Soraya Gaze, Patrick Driguez, Donald P Mcmanus, Denise L. Doolan, Mark S. Pearson, Angela Trieu, Geoffrey N. Gobert, Maria Victoria Periago, Tiago Antonio De Oliveira Mendes, Rodrigo Correa OliveiraAbstract:Schistosomiasis is a neglected tropical disease that is responsible for almost 300,000 deaths annually. Mass drug administration (MDA) is used worldwide for the control of Schistosomiasis, but chemotherapy fails to prevent reinfection with schistosomes, so MDA alone is not sufficient to eliminate the disease, and a prophylactic Vaccine is required. Herein, we take advantage of recent advances in systems biology and longitudinal studies in Schistosomiasis endemic areas in Brazil to pilot an immunomics approach to the discovery of Schistosomiasis Vaccine antigens. We selected mostly surface-derived proteins, produced them using an in vitro rapid translation system and then printed them to generate the first protein microarray for a multi-cellular pathogen. Using well-established Brazilian cohorts of putatively resistant (PR) and chronically infected (CI) individuals stratified by the intensity of their S. mansoni infection, we probed arrays for IgG subclass and IgE responses to these antigens to detect antibody signatures that were reflective of protective vs. non-protective immune responses. Moreover, probing for IgE responses allowed us to identify antigens that might induce potentially deleterious hypersensitivity responses if used as subunit Vaccines in endemic populations. Using multi-dimensional cluster analysis we showed that PR individuals mounted a distinct and robust IgG1 response to a small set of newly discovered and well-characterized surface (tegument) antigens in contrast to CI individuals who mounted strong IgE and IgG4 responses to many antigens. Herein, we show the utility of a vaccinomics approach that profiles antibody responses of resistant individuals in a high-throughput multiplex approach for the identification of several potentially protective and safe Schistosomiasis Vaccine antigens.
-
Enhanced Protective Efficacy of a Chimeric Form of the Schistosomiasis Vaccine Antigen Sm-TSP-2
2013Co-Authors: Mark S. Pearson, Annette M Dougall, Darren A. Pickering, Henry J. Mcsorley, Jeffrey M. Bethony, Leon Tribolet, Peter J. Hotez, Alex LoukasAbstract:The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund’s adjuvants, has been shown to be an efficacious Vaccine against murine Schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG1 and IgG3 from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubility enhancing fusion partner. We also expressed in E. coli a chimera called Sm-TSP-2/5B, which consisted of Sm-TSP-2 fused to the immunogenic 5B region of the hookworm aspartic protease and Vaccine antigen, Na-APR-1. Sm-TSP-2 formulated with alum/CpG showed significant reductions in adult worm and liver egg burdens in two separate murine Schistosomiasis challenge studies. Sm-TSP-2/5B afforded significantly greater protection than Sm-TSP-2 alone when both antigens were formulated with alum/CpG. The enhanced protection obtained with the chimeric fusion protein was associated with increased production of anti-Sm-TSP-2 antibodies and IL-4, IL-10 and IFN-c from spleen cells of vaccinated animals. Sera from 666 individuals from Brazil who were infected with S. mansoni were screened for potentially deleterious IgE responses to Sm-TSP-2. Anti-Sm-TSP-2 IgE to this protein was not detected (also shown previously for Na-APR-1), suggesting that the chimeric antigen Sm-TSP-2/5B could be used to safely and effectively vaccinate people in areas wher
Banchob Sripa - One of the best experts on this subject based on the ideXlab platform.
-
molecular characterization of a tetraspanin from the human liver fluke opisthorchis viverrini
PLOS Neglected Tropical Diseases, 2012Co-Authors: Supawadee Piratae, Banchob Sripa, Smarn Tesana, Malcolm K Jones, Erica Lovas, Veerachai Eursitthichai, Sirikanda ThanasuwanAbstract:Background The human liver fluke, Opisthorchis viverrini, is designated as a group 1 carcinogen, and is the major risk factor for cholangiocarcinoma in endemic countries throughout Southeast Asia. Proteins in the excretory-secretory products and tegumental surface membranes of the fluke have been proposed to play pivotal roles in parasite survival in the host, and subsequent pathogenesis. These macromolecules are therefore valid targets for the development of Vaccines and new drugs to control the infection. Tetraspanins (TSP) are prominent components of the tegument of blood flukes where they are essential for tegument formation, are directly exposed to the immune system, and are major targets for a Schistosomiasis Vaccine. We propose that similar molecules in the surface membranes of O. viverrini are integral to tegument biogenesis and will be efficacious Vaccine antigens. Methodology/Principal Findings The cDNA sequence encoding O. viverrini tetraspanin-1 (Ov-TSP-1) was identified and cloned. The Ov-tsp-1gene was isolated from a cDNA library. Ov-tsp-1 mRNA was expressed most highly in metacercariae and eggs, and to a lesser extent in juvenile and adult worms. Immunolocalization with adult flukes confirmed that Ov-TSP-1 was expressed in the tegument and eggs in utero. Western blot analysis of rOv-TSP-1 probed with sera from O. viverrini-infected humans and hamsters indicated that both hosts raise antibody responses against the native TSP. Using RNA interference we silenced the expression level of Ov-tsp-1 mRNA in adult flukes by up to 72% by 10 days after delivery of dsRNA. Ultrastructural morphology of adult worms treated with Ov-tsp-1 dsRNA displayed a distinctly vacuolated and thinner tegument compared with controls. Conclusions/Significance This is the first report of a tetraspanin from the tegument of a liver fluke. Our data imply that tetraspanins play important structural roles in the development of the tegument in the adult fluke. Potential uses of O. viverrini tetraspanins as novel interventions are discussed.
-
the secreted and surface proteomes of the adult stage of the carcinogenic human liver fluke opisthorchis viverrini
Proteomics, 2010Co-Authors: Jason Mulvenna, Banchob Sripa, Malcolm K Jones, Paul J Brindley, Jeffrey J Gorman, Michelle L Colgrave, Alun Jones, Sujeevi Nawaratna, Thewarach LahaAbstract:Infection with the human liver fluke, Opisthorchis viverrini, is a serious public health problem in Thailand, Laos and nearby locations in Southeast Asia. Both experimental and epidemiological evidence strongly implicate liver fluke infection in the etiology of one of the liver cancer subtypes, cholangiocarcinoma (CCA). To identify parasite proteins critical for liver fluke survival and the etiology of CCA, OFFGEL electrophoresis and multiple reaction monitoring were employed to characterize 300 parasite proteins from the O. viverrini excretory/secretory products and, utilizing selective labeling and sequential solubilization, from the host-exposed tegument. The excretory/secretory included a complex mixture of proteins that have been associated with cancers, including proteases of different mechanistic classes and orthologues of mammalian growth factors and anti-apoptotic proteins. Also identified was a cysteine protease inhibitor which, in other helminth pathogens, induces nitric oxide production by macrophages, and, hence may contribute to malignant transformation of inflamed cells. More than 160 tegumental proteins were identified using sequential solubilization of isolated teguments, and a subset of these was localized to the surface membrane of the tegument by labeling living flukes with biotin and confirming surface localization with fluorescence microscopy. These included annexins, which are potential immuno-modulators, and orthologues of the Schistosomiasis Vaccine antigens Sm29 and tetraspanin-2. Novel roles in pathogenesis were suggested for the tegument-host interface since more than ten surface proteins had no homologues in the public databases. The O. viverrini proteins identified here provide an extensive catalogue of novel leads for research on the pathogenesis of opisthorchiasis and the development of novel interventions for this disease and CCA, as well as providing a scaffold for sequencing the genome of this fluke.
Thewarach Laha - One of the best experts on this subject based on the ideXlab platform.
-
the secreted and surface proteomes of the adult stage of the carcinogenic human liver fluke opisthorchis viverrini
Proteomics, 2010Co-Authors: Jason Mulvenna, Banchob Sripa, Malcolm K Jones, Paul J Brindley, Jeffrey J Gorman, Michelle L Colgrave, Alun Jones, Sujeevi Nawaratna, Thewarach LahaAbstract:Infection with the human liver fluke, Opisthorchis viverrini, is a serious public health problem in Thailand, Laos and nearby locations in Southeast Asia. Both experimental and epidemiological evidence strongly implicate liver fluke infection in the etiology of one of the liver cancer subtypes, cholangiocarcinoma (CCA). To identify parasite proteins critical for liver fluke survival and the etiology of CCA, OFFGEL electrophoresis and multiple reaction monitoring were employed to characterize 300 parasite proteins from the O. viverrini excretory/secretory products and, utilizing selective labeling and sequential solubilization, from the host-exposed tegument. The excretory/secretory included a complex mixture of proteins that have been associated with cancers, including proteases of different mechanistic classes and orthologues of mammalian growth factors and anti-apoptotic proteins. Also identified was a cysteine protease inhibitor which, in other helminth pathogens, induces nitric oxide production by macrophages, and, hence may contribute to malignant transformation of inflamed cells. More than 160 tegumental proteins were identified using sequential solubilization of isolated teguments, and a subset of these was localized to the surface membrane of the tegument by labeling living flukes with biotin and confirming surface localization with fluorescence microscopy. These included annexins, which are potential immuno-modulators, and orthologues of the Schistosomiasis Vaccine antigens Sm29 and tetraspanin-2. Novel roles in pathogenesis were suggested for the tegument-host interface since more than ten surface proteins had no homologues in the public databases. The O. viverrini proteins identified here provide an extensive catalogue of novel leads for research on the pathogenesis of opisthorchiasis and the development of novel interventions for this disease and CCA, as well as providing a scaffold for sequencing the genome of this fluke.
