Gigantocotyle Explanatum Research Articles

Affinity purification, identification, and biochemical characterization of Gamma-glutamyl transpeptidase, a membrane anchored enzyme of Gigantocotyle explanatum.

Gamma-glutamyl transpeptidase is an enzyme that facilitates the transfer of glutamyl groups from glutamyl peptides to other peptides or water. Additionally, it also participates in important processes such as amino acid transport, cellular redox control, drug detoxification, apoptosis, and DNA fragmentation in a various organism. In the present study, GGT activity in Gigantocotyle explanatum was examined in order to characterize the enzyme in the helminth system. GGT is isolated using membrane solubilization and purified through affinity column chromatography (Con-A Sepharose column). Km and Vmax values, as well as the optimal pH, optimal temperature, and incubation period, are also determined using enzyme kinetics. The hetero-dimeric property of the enzyme is demonstrated by the purified GGT, which yielded two subunits of 65.5 and 55kDa. The optimal pH and temperature are found to be 8.0 and 37°C, respectively. While assessing the optimal incubation time of the enzyme, it was observed that the purified GGT not only retained its functional integrity up to 15min but also reflected considerable thermostability at higher temperatures, by retaining 78% and 25% of its initial activities at 50°C and 60°C, respectively. One millimolar concentration of 6-Diazo-5-Oxo Nor-isoleucine (DON), a specific inhibitor of GGT, completely abolished GGT activity. These results suggest that GGT in these worms is a catalytically active enzyme with distinguishing characteristics that can be used for further study to comprehend its function in amphistome biology and in host-parasite relationships, especially since the potential therapeutic candidacy of the GGT enzyme has already been indicated in these groups of organisms.

Antihelminthic effect of thymoquinone against biliary amphistome, Gigantocotyleexplanatum

Recent research on the emergence of parasitic resistance to commonly prescribed anthelmintics has sparked a greater interest in finding novel therapeutic molecules, including those derived from plants. The use of medicinal plants and their derivatives has been viewed as an alternative source of anti-parasitic compounds and as being safe in comparison to synthetic medications due to the absence of adverse effects, ease of accessibility, and little to no expense.Consequently, in the current study, thymoquinone (TQ), an active component of Nigella sativa (Black cumin), has been tested to see their effect on the activity of some important parameters of Gigantocotyle explanatum worms, including Gamma-glutamyl Transpeptidase (GGT), glutathione (GSH), Glutathione-S-Transferase (GST), Superoxide dismutase (NO). Additionally, various other survival indicators are also used, such as assays for motility, tegument damage, and DNA fragmentation.G. explanatum adult flukes were in vitro treated to thymoquinone at various concentrations for 3 h at 37 °C. Even though all of the worms were still alive after 3 h of exposure, there was a substantial (p < 0.05) reduction in worm motility at a concentration of 90 M. There were pronounced tegumental disturbances, a loss of surface annulations, and erosion in the papillae posterior region and around the acetabulum. A significant (p < 0.05) decrease in glutathione-S-transferase and superoxide dismutase activity and reduced glutathione (GSH) level was observed. A significant inhibition of Gamma-glutamyl Transpeptidase (GGT) in thymoquinone treated worms was also evident. Thymoquinone and GGT also displayed a high interaction during in silico molecular docking, suggesting that this combination may be more effective at inhibiting the antioxidant enzymes of G. explanatum. The present findings suggest that thymoquinone would reduce the worm capacity for detoxification, while GGT inhibition would have a major impact on their ability to transport amino acids across the tegument. Thymoquinone thus seemed to be a promising anthelmintic compound for future investigations.

Serological diagnostic potential of the 38-72 kDa somatic antigen of Gastrothylax crumenifer in buffaloes using the Indirect Enzyme-Linked Immunosorbent Assay

Paramphistomosis, caused by digenetic trematodes of the superfamily Paramphistomoidea, causes heavy economic losses in terms of reduced fertility, milk and meat production in the livestock industry. In the present study, somatic and excretory secretory antigens isolated from 500 live Gastrothylax crumenifer were assessed for their diagnostic potential by using an antibody detection enzyme immunoassay. Prior to the enzyme immunoassay, the somatic and excretory/secretory (ES) antigens of G. crumenifer were subjected to SDS-PAGE and Western blot (WB) for the detection of immunogenic proteins. Indirect ELISA analysis was performed on sera from buffaloes naturally infected with G. crumenifer, with control sera of buffaloes infected with Gigantocotyle explanatum, Fasciola spp., Cotylophoron /Paramphistomum spp. The SDS-PAGE results of the somatic products of G. crumenifer identified proteins were between 10-123 kDa, showing a maximum abundance of 10, 15, 25-28, 36, 38-72, 95-123 kDa proteins. The most abundant proteins recorded in ES product were ≥95, 72, 55 and 40 kDa. The antigenic analysis of somatic proteins using WB revealed reactive polypeptides of a size between 55-70 kDa, while metabolic extracts did not show reactivity with naturally infected buffalo sera. The sensitivity and specificity of the ELISA test for 38-72 kDa somatic antigens were 85.71% and 89.74%, respectively. The cross-reactivity with other trematode sera was 16-20%. Antibodies were tested against the 38-72 kDa somatic antigens, and 19.69% (39/198) of buffaloes were found positive, while 12.1% (24/198) presented infection in the fecal/postmortem examination. The study confirmed that ELISA established for the 38-72 kDa somatic antigens of G. crumenifer had diagnostic potential against paramphistome infections.

Morphological, histopathological and secondary structure analysis of second internal transcribed spacer (ITS-2) region of Gigantocotyle explanatum (Trematoda: Paramphistomidae) in buffaloes of Pakistan

Liver infections due to amphistomes in buffaloes cause significant economic losses in livestock sector. The present study investigated the classical morphological features of adult amphistomes combined with histopathology and molecular identity in slaughtered buffaloes from Khyber Pakhtunkhwa, Pakistan. Adult amphistome were collected and morphologically characterized as Gigantocotyle explanatum. Morphometric measurement (n=50) were obtained with 12.05±1.68 mm in length and 5.77±0.81 mm in width, and the values of sagittal section was 6.35±1.03 x 2.98±0.50 mm in size. Severe bile duct pathology was observed with fibrosis of the duct wall with an irregular epithelial border, hyperplasia and inflammatory response with numerous neutrophils and eosinophils. The molecular identity of G. explanatum within Paramphistomidae was confirmed by ITS-2 rDNA sequences phylogenetic analysis based on maximum likelihood method. The genetic data based on ITS-2 secondary structure of G. explanatum consisted of four helix, Helix I, II and IV were conserved as compared with other closely related reference taxa of family Paramphistomidae and Gastrothylacidae. Helix III expressed some variations. The study concluded that rDNA ITS-2 and secondary structure information provides a guide for other researchers to determine the molecular taxonomic position of Paramphistomidae trematodes, data will support future clinical studies and control measures to reduce the amphistomiasis in buffaloes.

Antihelminthic Effect of Thymoquinone Leads to GGT/GSH Imbalance and Apoptotic Like Events in the Biliary Amphistome, Gigantocotyle Explanatum

Antihelminthic Effect of Thymoquinone Leads to GGT/GSH Imbalance and Apoptotic Like Events in the Biliary Amphistome, Gigantocotyle Explanatum

Affinity Purification, Identification and Biochemical Characterization of Gamma-Glutamyl Transpeptidase, a Membrane Anchored Enzyme of Gigantocotyle Explanatum

Affinity Purification, Identification and Biochemical Characterization of Gamma-Glutamyl Transpeptidase, a Membrane Anchored Enzyme of Gigantocotyle Explanatum

Glutathione-S-transferase: an important diagnostic antigen of liver amphistome Gigantocotyle explanatum, infecting the Indian water buffalo

The foodborne trematodiases pose a significant health problem to the animals as well as the human population living in close proximities with the livestock and are still considered as the neglected tropical diseases by the World Health Organisation. The digenetic trematode, Gigantocotyle explanatum infecting the liver of Indian water buffalo, Bubalus bubalis, has been identified as one of the most common helminth parasite responsible for the disease, amphistomosis, in livestock. Despite huge abattoir prevalence, the epidemiological data and the actual economic losses incurred due to this parasite alone are yet to be established probably due to the limitations of routinely used diagnostic tests. The gold standard for the confirmation of such infections under field conditions is still the fecal egg count (FEC). However, the poor sensitivity and cumbersome nature of these tests necessitates the development of a more sensitive, reliable and easy to perform workflow/method. Immunological diagnosis of helminthic infections is still considered as an alternative to the FEC. Therefore, efforts have been made to utilize glutathione-S-transferase (GST), a vitally significant molecule of the adult G. explanatum, for the serodiagnosis of amphistomosis under both laboratory and field conditions.The GST antigen was first affinity purified from the somatic extract of the adult worms since its highest level was recorded in the somatic extracts followed by eggs and the excretory/secretory products. A five-fold affinity purified native GST antigen of about 25 kDa was found to be highly immunogenic as evident from high titre (1:25,600) of the polyclonal antibodies raised in the rabbits. The immunoblotting results revealed differential presence of GST in the adult worms, their eggs and excretory/secretory products. The immunolocalization studies revealed that the vitelline glands are the major source of GST in liver amphistome. Further, we were able to successfully screen animals naturally infected with G. explanatum using anti GST polyclonal antibodies in dot blot assay. High levels of both circulating GST antigen and anti GST antibodies were detected in the serum of the animals naturally infected with G. explanatum, while no cross reactivity was observed with the tropical liver fluke, F. gigantica which often infects the buffalo liver concurrently. The findings of the present study indicate that GST could be used as an important antigen for the diagnosis of G. explanatum infection in Indian water buffaloes.

Monoclonal antibody against Fasciola gigantica glutathione peroxidase and their immunodiagnosis potential for fasciolosis

Glutathione peroxidases (GPx), major antioxidant enzymes, secreted by Fasciola spp., are important for the parasite evasion and protection against the host’s immune responses. In the present study, a monoclonal antibody (MoAb) against recombinant F. gigantica glutathione peroxidase (rFgGPx) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with rFgGPx. This MoAb (named 7B8) is IgG1 with κ light chains, and it reacted specifically with rFgGPx at a molecular weight 19 kDa as shown by immunoblotting, and reacted with the native FgGPx in the extracts of whole body (WB), metacercariae, newly excysted juveniles (NEJs), 4 week-old juveniles and adult F. gigantica as shown by indirect ELISA. It did not cross react with antigens in WB fractions from other adult trematodes, including Fischoederius cobboldi, Paramphistomum cervi, Setaria labiato-papillosa, Eurytrema pancreaticum, Gastrothylax crumenifer and Gigantocotyle explanatum. By immunolocalization, MoAb against rFgGPx reacted with the native protein in the tegument, vitelline cells, and eggs of adult F. gigantica. In addition, the sera from mice experimentally infected with F. gigantica were tested positive by this indirect sandwich ELISA. This result indicated that FgGPx is an abundantly expressed parasite protein that is secreted into the tegumental antigens (TA), therefore, FgGPx and its MoAb may be used for immunodiagnosis of both early and late fasciolosis gigantica in animals and humans.

In vitro anthelmintic effect of biologically synthesized silver nanoparticles on liver amphistome, Gigantocotyle explanatum

In order to ensure global food security a rationale approach is required to control all those factors which directly or indirectly affect the food productivity. The neglected helminthic diseases alone are responsible for huge economic losses to the agrarian stakeholders. The problem is further compounded by the emerging drug resistance in flukes against the commonly used anthelmintics like triclabendazole. Therefore, the search for alternatives including the nano-based approaches has become a necessity to develop future control strategies. In the present study the effect of biologically synthesized silver nanoparticles (AgNPs) was investigated on an economically important amphistome parasite, Gigantocotyle explanatum, obtained from the infected liver of the Indian water buffaloes, Bubalus bubalis. In vitro treatment of the adult worms with different doses of AgNPs severely affected the worm motility and caused ROS mediated damages in the treated flukes. The antioxidant system and the detoxification ability of the worms appeared to be disrupted along with pronounced DNA damage in the treated worms as compared to the controls. Following the treatment of worms with different concentrations of AgNPs there was a significant (p < 0.05) increase in lipid peroxidation and protein carbonylation levels which are the key oxidative stress markers. The tegumental surface which is metabolically active, was severely damaged as evident from the loss of papillae, severe blebbing, shearing and erosion of the surface structures. Such topographical disruptions would facilitate the penetration of the nanoparticles deep within the tissues that might greatly reduce the invasive potential of the flukes as evident from the decreased motility. Taken together our findings suggest that the AgNPs posses great anthelmintic potential and could be further exploited for the development of anthelmintic formulations which may be tested in vivo.

The anthelmintic activity of 1,10-phenanthroline, a metalloenzyme inhibitor

Paramphistomosis is a chronic, debilitating parasitic disease of livestock prevalent in the tropical and sub-tropical countries. Globally there is a heavy reliance on anthelmintics but concerns over drug resistance encourage the search for new leads. Metalloproteinases play a significant role in the biology and life cycle of parasitic helminths. The efficacy of metalloproteinase inhibitor, 1,10-Phenanthroline (1,10-phe) which is commonly used as a specific enzyme inhibitor in biochemical assays, was tested in vitro on Gigantocotyle explanatum tegument as a marker of anthelmintic action. The scanning electron microscopy revealed that the tegumental surface exhibited considerable changes in the worms treated with the metalloenzyme inhibitor, 1,10-phe. The untreated control worms appeared normal showing smooth tegumental surface with abundant dome shaped papillae in the anterior to mid region, while their density was less around the acetabulum which serves as a hold-fast organ helping the worms to remain attached in biliary passage. The 1,10-phe produced significant tegumental damage when the liver amphistomes were in vitro exposed to this compound at 12.5 µM concentration. The surface changes appeared in the form of edematous ridges with prominent furrows and erosion of the dome shaped papillae with rosette shaped deep lesions as a result of which deep parenchymatous tissues were exposed. The collapse of sensory bulbs as well as sloughing of tegument, particularly in the anterior-mid region was observed. The nature of damage could be comparable to various anthelmintics used in previous studies. To the best of our knowledge this is the first report of direct exposure of amphistome worms to zinc metallo-enzyme inhibitor, however, further in vivo studies are required to ascertain the anthelmintic efficacy of 1,10-phe.

Genetic Characterization of Gigantocotyle explanatum from Buffaloes in Northwestern Pakistan

Genetic Characterization of Gigantocotyle explanatum from Buffaloes in Northwestern Pakistan

Immunolocalization and immunodetection of the excretory/secretory (ES) antigens of Fasciola gigantica.

The digenetic trematode Fasciola gigantica is a parasite of great agricultural and economic importance. Along with Fasciola hepatica, F. gigantica incurs huge economic losses to the agricultural sector. Because of unavailability of an effective and commercial vaccine, the earliest diagnosis of the disease is the only way to control the disease. The conventional coprological techniques are able to detect the disease only after the parasites get matured and starts releasing their eggs with the faeces of host, therefore prepatent infection remain undiagnosed. The alternative method is by serological tests that uses circulatory antigens. Despite high sensitivity, their reliability is quite low because of the common antigens shared between different helminth parasites. To overcome this, investigation was shifted to identify the copro-antigens which could be more sensitive and reliable. In the present study, we tried to identify some of the immunodominant proteins from the Excretory Secretory (ES) product of F. gigantica which can be further characterized and used for early detection of infection and also as drug and vaccine candidates. The ES products of F. gigantica were collected and used for raising the polyclonal antibody in rabbit. The polypeptide profile was generated as well as immunogenic polypeptides were identified. The Source of ES antigen was immunolocalized using confocal microscopy and dot blot assay was performed to diagnose field infection. The polypeptide profile of ES products revealed a total of 24 polypeptides out of which 12 immunogenic polypeptides were identified by western blotting. Confocal micrographs showed the immunolocalization of antigens in the intestinal caecae, vitalline glands, gonads as well as in the tegument of the worm. The dot blot assay confirmed the utility of ES products for the detection of field infection. Subsequently, cross reactivity was found negative with Gigantocotyle explanatum; an amphitome parasite of same habitat. However, the cross reactivity with other helminths needs to be worked out.

In vitro effect of metrifonate on the indices of oxidative stress in Gigantocotyle explanatum

Helminth infections in general and digenetic trematodes in particular cause a huge economic loss globally to our livestock. Gigantocotyle explanatum is a digenetic amphistome that infects the bile ducts of water buffalo and are highly prevalent in tropical and sub-tropical countries. In the present study, effects of an organophosphate compound, Metrifonate (MF) in three doses, viz., 9.4 × 10−5 M (Dose I), 14.4 × 10−5 M (Dose II), and 19.4 × 10−5 M (Dose III), have been studied in vitro, on the motility and on some enzymatic and non-enzymatic oxidative stress indices in G. explanatum. The worm's motility and their non-enzymatic oxidative stress biomarkers like lipid peroxides measured as thiobarbituric acid-reactive substances (TBARS) and reduced glutathione (GSH) were disrupted significantly in a dose-dependent manner. However, the enzymatic oxidative stress biomarkers like glutathione-S-transferase (GST) and superoxide dismutase (SOD) were affected by MF treatment in a biphasic manner. Exposure to Dose I significantly stimulated the activities of both GST and SOD, whereas exposure to Doses II and III resulted into significant inhibition in a dose-dependent manner. Our findings suggest that MF has potential to be a strong and effective anthelmintic, however, further studies in vitro as well as in vivo are needed to explore further these observations and understand the exact mode of MF action in G. explanatum and other trematodes of veterinary economic importance.

Phenotyping of Amphistomes, and Pathological, Hematological and Bile Biochemical Response to Gigantocotyle explanatum Infection in Buffaloes

Phenotyping of Amphistomes, and Pathological, Hematological and Bile Biochemical Response to Gigantocotyle explanatum Infection in Buffaloes

Production and characterization of a monoclonal antibody specific to 16kDa antigen of Paramphistomum gracile.

A number of monoclonal antibodies (MoAbs) against the 16kDa antigen of Paramphistomum gracile (16kDaAgPg) were produced in vitro by hybridoma technique. Reactivity and specificity of these MoAbs were evaluated by ELISA and immunoblotting assays. Seven MoAb clones were selected from the stable hybridoma clones, namely 1D10, 2D7, 3B10, 3D9, 4F1, 4G4, and 5G12. It was found to be IgM and kappa light chain isotypes. By immunoblotting and ELISA, all MoAbs reacted with purified 16kDaAgPg at molecular weight (MW) of 16kDa and with the native 16kDa antigen at MW of 16kDa in the whole body (WB) and excretory-secretory (ES) fractions, but not with tegumental antigens (TA) of adult fluke. All of these MoAbs showed no cross-reactions with antigens of other parasites commonly found in ruminants, including Eurytrema pancreaticum, Gigantocotyle explanatum, Schistosoma spindale, Moniezia benedeni, Avitellina centripunctata, Haemonchus placei, Trichuris sp., and Setaria labiato-papillosa. Localization and distribution of the native 16kDaAg in adult P. gracile by immunohistochemistry, using MoAbs as probes, showed that the native 16kDaAg was present in high concentration in the cytoplasm of vitelline cells, eggshell globules, and the shells of eggs, but not in the tegument, muscle, parenchymal cells, and cecum of adult fluke. This finding indicated that the 16kDaAg is a copiously expressed parasite protein that is released into the ES; thus, 16kDaAg and its MoAb could be a good candidate for immunodiagnosis of paramphistomosis in ruminants.

Anthelmintic Effect of Biocompatible Zinc Oxide Nanoparticles (ZnO NPs) on Gigantocotyle explanatum, a Neglected Parasite of Indian Water Buffalo.

Helminth parasites of veterinary importance cause huge revenue losses to agrarian economy worldwide. With the emergence of drug resistance against the current formulations, there is a need to focus on the alternative approaches in order to control this menace. In the present study, biocompatible zinc oxide nanoparticles (ZnO NPs) were used to see their in vitro effect on the biliary amphistomes, Gigantocotyle explanatum, infecting Bubalus bubalis because these nanoparticles are involved in generation of free radicals that induce oxidative stress, resulting in disruption of cellular machinery. The ZnO NPs were synthesized by using egg albumin as a biotemplate and subsequently characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction and Spectrophotometrical, which showed that ZnO NPs were highly purified wurtzite type polycrystals, with a mean size of 16.7 nm. When the parasites were treated with lower concentrations (0.004% and 0.008%) of the ZnO NPs, the worms mounted a protective response by stimulating the antioxidant system but the treatment of G. explanatum with 0.012% ZnO NPs produced significant inhibition of the antioxidant enzymes like superoxide dismutase (SOD) (p< 0.05) and glutathione S- transferase (GST) (p<0.01), while the level of malondialdehyde (MDA), a lipid peroxidation marker, was significantly (p< 0.01) elevated. SEM and histopathology revealed pronounced tegumental damage showing the disruption of surface papillae and the annulations, particularly in the posterior region near acetabulum. The under expression of a number of polypeptides, loss of worm motility in a time dependent manner, further reflect strong anthelmintic potential of ZnO NPs. It can be concluded that the anthelmintic effect might be due to the production of reactive oxygen species that target a variety of macromolecules such as nucleic acid, protein and lipids which are involved in different cellular processes.

Somatic antigens of tropical liver flukes ameliorate collagen-induced arthritis in wistar rats.

Parasitic helminths polarize immune response of their vertebrate hosts towards anti-inflammatory Th2 type and therefore it is hypothesized that they may suppress the inflammatory conditions in autoimmune disorders. The present study was undertaken to investigate in vivo immunomodulatory and therapeutic potential of somatic antigens (Ag) of liver infecting digenetic trematodes [Fasciola gigantica (Fg) and Gigantocotyle explanatum (Ge)] in collagen-induced arthritic (CIA) Wistar rats. The CIA rats were administered subcutaneously with different doses (50 μg, 100 μg and 150 μg) of somatic antigens of Fg and Ge, daily for 21 days, the time period required to establish infection in natural host (Bubalus bubalis). Thereafter, the control, diseased and treated rats were compared for different parameters viz. hind paw thickness; serum interleukins, IL-4 and IL-10, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ); expression level of matrix metalloproteinases (MMPs) -2, -9, -13 and nitric oxide (NO) in knee joints and patellar morphology. The CIA rats treated with different antigens, Fg-Ag and Ge-Ag, show significant amelioration of the disease by down regulation of serum TNF-α and IFN-γ (p< 0.05) and upregulation of IL-4 and IL-10 cytokines (p< 0.05); inhibition (p< 0.05) of MMPs (-2,-9,-13) and NO in knee joints and improved patellar morphology with decreased synovial hypertrophy and reduced infiltration of ploymorphonuclear cells. The activity of pro as well as active MMPs (-2 and -9) and active MMP-13 in knee joints of CIA rats was very high compared to the control and treatment groups, suggesting the extent of collagen degradation in CIA rats. Interestingly, the highest dose (150 μg) of Ge-Ag almost wiped out MMP-13 expression. The overall findings suggest that the somatic proteins of Ge-Ag appeared to be therapeutically more effective than Fg-Ag, reflecting interspecific molecular differences which could contribute to the ability of these worms to successfully ameliorate the pathology of CIA.

Protection against Fasciola gigantica infection in mice by vaccination with recombinant juvenile-specific cathepsin L

Fasciola gigantica cathepsin L1H (FgCatL1H) is one of the major cathepsin L released by juveniles of F. gigantica to aid in the invasion of host's tissues. Due to its high sequence similarity with other cathepsin L (CatL) isoforms of late stage F. gigantica, it was considered to be a good vaccine candidate that can block all CatL-mediated protease activities and affect juveniles as well as adult parasites. In this study, recombinant proFgCatL1H protein expressed in yeast, Pichia pastoris, system was mixed with Freund's adjuvants and used to subcutaneously immunize mice that were later challenged with metacercariae of F. gigantica. The percentage of worm protection in the rproFgCatL1H-vaccinated mice compared to the non-immunized and adjuvant control mice were approximately 62.7% and 66.1%, respectively. Anti-rproFgCatL1H antisera collected from vaccinated mice reacted specifically with rproFgCatL1H and other cathepsin L isoforms of F. gigantica, but the antibodies did not cross react with antigens from other trematode and nematode parasites, including Eurytrema pancreaticum, Opisthorchis viverrini, Fischoederius cobboldi, Cotylophoron cotylophorum, Gigantocotyle explanatum, Paramphistomum cervi, and Setaria labiato-papillosa. The levels of IgG1 and IgG2a in mouse sera increased significantly at two weeks after immunization and were highest during the sixth to eighth weeks after immunization. The IgG1 level was higher than IgG2a at all periods of immunization, implicating the dominance of the Th2 response. The levels of IgG1 and IgG2a in the immune sera were shown to be strongly correlated with the numbers of worm recovery, and the correlation coefficient was higher for IgG1. The levels of serum aspartate aminotransferase and alanine transaminase were significantly lower in the sera of rproFgCatL1H-vaccinated mice than in the infected control mice indicating a lower degree of liver damage. This study demonstrated a high potential of FgCatL1H vaccine, and its efficacy is currently being studied in the larger economic animals.

2D-PAGE analysis of the soluble proteins of the tropical liver fluke, Fasciola gigantica and biliary amphistome, Gigantocotyle explanatum, concurrently infecting Bubalus bubalis.

The digenetic trematodes, Fasciola gigantica and Gigantocotyle explanatum, belonging to the family Fasciolidae and Paramphistomidae respectively, have been often found to concurrently infect the liver of Indian water buffalo Bubalus bubalis, causing serious pathological damage to the vital organ, incurring huge economic losses. In the present study the soluble gene products of both F. gigantica and G. explanatum were analyzed by 2 dimensional polyacrylamide gel electrophoresis. The soluble proteomic profile revealed considerable similarity as well as differences in the size, distribution pattern, total number, the isoelectric point (pI) and molecular weight (Mr) of the resolved polypeptide spots. The maximum number of polypeptide spots with a molecular weight range of >10 to 160kDa were recorded with a pI range of 7-9 followed by pI range of 5-7, 9-10 and 3-5 in both the parasites. However, considerable variation was recorded in the Mr of the polypeptides belonging to each pI range. The genetic heterogeneity could be an obvious contributing factor for such differences but some polypeptides appeared to be conserved in the two species. The molecular similarities and the habitat preference by these worms may be a consequence of microenvironmental cues that guide these flukes to reach their habitat through different routes and establish a successful host-parasite relationship.

Monoclonal antibody against recombinant Fasciola gigantica cathepsin L1H could detect juvenile and adult cathepsin Ls of Fasciola gigantica.

Cathepsin Ls (CatLs), the major cysteine protease secreted by Fasciola spp., are important for parasite digestion and tissue invasion. Fasciola gigantica cathepsin L1H (FgCatL1H) is the isotype expressed in the early stages for migration and invasion. In the present study, a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1H (rFgCatL1H) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with recombinant proFgCatL1H (rproFgCatL1H). This MoAb is an immunoglobulin (Ig)G1 with κ light chain isotype. The MoAb reacted specifically with rproFgCatL1H, the native FgCatL1H at a molecular weight (MW) 38 to 48 kDa in the extract of whole body (WB) of metacercariae and newly excysted juvenile (NEJ) and cross-reacted with rFgCatL1 and native FgCatLs at MW 25 to 28 kDa in WB of 2- and 4-week-old juveniles, adult, and adult excretory-secretory (ES) fractions by immunoblotting and indirect ELISA. It did not cross-react with antigens in WB fractions from other parasites, including Gigantocotyle explanatum, Paramphistomum cervi, Gastrothylax crumenifer, Eurytrema pancreaticum, Setaria labiato-papillosa, and Fischoederius cobboldi. By immunolocalization, MoAb against rFgCatL1H reacted with the native protein in the gut of metacercariae and NEJ and also cross-reacted with CatL1 in 2- and 4-week-old juveniles and adult F. gigantica. Therefore, FgCatL1H and its MoAb may be used for immunodiagnosis of both early and late fasciolosis in ruminants and humans.