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McManus DP. The Search for a Schistosomiasis Vaccine: Australia's Contribution. Vaccines (Basel) 2021; 9:vaccines9080872. [PMID: 34451997 PMCID: PMC8402410 DOI: 10.3390/vaccines9080872] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/05/2021] [Accepted: 08/05/2021] [Indexed: 01/10/2023] Open
Abstract
Schistosomiasis, a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, results in considerable human morbidity in sub-Saharan Africa, in particular, but also parts of the Middle East, South America, and Southeast Asia. The anti-schistosome drug praziquantel is efficacious and safe against the adult parasites of all Schistosoma species infecting humans; however, it does not prevent reinfection and the development of drug resistance is a constant concern. The need to develop an effective vaccine is of great importance if the health of many in the developing world is to be improved. Indeed, vaccination, in combination with other public health measures, can provide an invaluable tool to achieve lasting control, leading to schistosomiasis elimination. Australia has played a leading role in schistosomiasis vaccine research over many years and this review presents an overview of some of the significant contributions made by Australian scientists in this important area.
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Affiliation(s)
- Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
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Wilson MS, Cheever AW, White SD, Thompson RW, Wynn TA. IL-10 blocks the development of resistance to re-infection with Schistosoma mansoni. PLoS Pathog 2011; 7:e1002171. [PMID: 21829367 PMCID: PMC3150278 DOI: 10.1371/journal.ppat.1002171] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 06/03/2011] [Indexed: 01/26/2023] Open
Abstract
Despite effective chemotherapy to treat schistosome infections, re-infection rates are extremely high. Resistance to reinfection can develop, however it typically takes several years following numerous rounds of treatment and re-infection, and often develops in only a small cohort of individuals. Using a well-established and highly permissive mouse model, we investigated whether immunoregulatory mechanisms influence the development of resistance. Following Praziquantel (PZQ) treatment of S. mansoni infected mice we observed a significant and mixed anti-worm response, characterized by Th1, Th2 and Th17 responses. Despite the elevated anti-worm response in PBMC's, liver, spleen and mesenteric lymph nodes, this did not confer any protection from a secondary challenge infection. Because a significant increase in IL-10-producing CD4+CD44+CD25+GITR+ lymphocytes was observed, we hypothesised that IL-10 was obstructing the development of resistance. Blockade of IL-10 combined with PZQ treatment afforded a greater than 50% reduction in parasite establishment during reinfection, compared to PZQ treatment alone, indicating that IL-10 obstructs the development of acquired resistance. Markedly enhanced Th1, Th2 and Th17 responses, worm-specific IgG1, IgG2b and IgE and circulating eosinophils characterized the protection. This study demonstrates that blocking IL-10 signalling during PZQ treatment can facilitate the development of protective immunity and provide a highly effective strategy to protect against reinfection with S. mansoni. Schistosomes are zoonotic parasitic helminths that infect hundreds of millions of people worldwide. Despite effective chemotherapy, schistosomiasis- the disease caused by these parasites, still plagues tropical regions of the world. This is due, in part, to poor resistance to reinfection resulting in high re-infection rates following treatment. This lack of resistance is intriguing, as effective treatment relies upon drug-induced parasite damage combined with host immune mediated killing. Furthermore, it has been widely reported that post-treatment, individuals develop and retain elevated levels of anti-parasite immune responses. We therefore asked why resistance to re-infection is so poor, despite the development of significant anti-worm responses post-treatment. It is essential that immune responses are controlled by various immunosuppressive mechanisms to prevent immune-mediated pathologies. However, a robust immunoregulatory response may obstruct the development of protective immunity. Thus, a balanced immune response providing a non-pathogenic yet effective immune response may be required for the development of effective resistance to reinfection. Understanding the immunological mechanisms of resistance to re-infection and the role of effector and regulatory responses may aid in the development of more effective vaccines and treatment strategies for schistosomaisis. This study suggests that combining chemotherapy with drugs that block IL-10 might provide an improved strategy to elicit acquired immunity to this parasite.
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Affiliation(s)
- Mark S Wilson
- Immunopathogensis Section, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Marlyand, United States of America.
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Is there reduced susceptibility to praziquantel in Schistosoma japonicum? Evidence from China. Parasitology 2011; 137:1905-12. [PMID: 20810006 DOI: 10.1017/s0031182010001204] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Praziquantel is widely used for the treatment of human schistosomiasis. However, in recent years, there has been increasing concern about the resistance of Schistosoma species to praziquantel. The study described here was designed to evaluate the current susceptibility to praziquantel in S. japonicum in China. During the non-transmission period of schistosomiasis, a random sample of 4760 subjects from the main endemic foci of China were examined using parasitological stool examination. In total, 584 subjects were identified as being infected with S. japonicum, with a prevalence rate of 12.27%. Among them, 565 stool-egg-positive subjects were treated with praziquantel in a single oral dose of 40 mg/kg. Six weeks post-treatment, among the 505 villagers re-examined, 480 (95.05%) had no detectable S. japonicum eggs. Twenty-one subjects still excreting eggs after the first treatment were treated with praziquantel for the second time. All stool samples, including those from those participants with second treatment were re-examined 6 weeks after the second treatment, and no stool-egg-positives were found. The results indicate that the current efficacy of praziquantel against S. japonicum is still high and has not changed after more than 2 decades of repeated, expanded chemotherapy in the main endemic areas of China. It is suggested that no evidence of tolerance or resistance to praziquantel in S. japonicum was detected in China.
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Determination of Schistosoma japonicum circulating antigens in dilution serum by piezoelectric immunosensor and S/N enhancement. Biosens Bioelectron 2008; 24:136-40. [PMID: 18490150 DOI: 10.1016/j.bios.2008.03.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 03/02/2008] [Accepted: 03/19/2008] [Indexed: 11/24/2022]
Abstract
A piezoelectric immunosensor assay was developed with immobilizing immunoglobulin G (IgG) as a probe to detect Schistosoma japonicum circulating antigens (SjCAg). Analytical strategy utilizes the polyclonal antibodies with broad-spectrum recognition to a complex target with high specificity. The immobilized antibodies were purified from immunized rabbit's sera (im-S) and infected rabbit's sera (inf-S) by S. japonicum. The detection capacities of antibodies were compared between the sera of different phenotypes and purified fractions. The sample dilution ratios were also evaluated and optimized. Additionally, the sera with a variety of infection degrees for validation could be discriminated quantitatively. The linear dose-response relationship indicates that the systematic sensitivity of this method is below 150 Hz and the lowest limit of detectable range is above 500 cercariae of S. japonicum infection for 2 weeks. The novel immunosensor technique is well potential to determine the SjCAg in serum samples for clinical diagnosis of parasitosis in early stage.
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Jolly ER, Chin CS, Miller S, Bahgat MM, Lim KC, DeRisi J, McKerrow JH. Gene expression patterns during adaptation of a helminth parasite to different environmental niches. Genome Biol 2007; 8:R65. [PMID: 17456242 PMCID: PMC1896014 DOI: 10.1186/gb-2007-8-4-r65] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 01/29/2007] [Accepted: 04/24/2007] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Schistosome bloodflukes are complex trematodes responsible for 200 million cases of schistosomiasis worldwide. Their life cycle is characterized by a series of remarkable morphological and biochemical transitions between an invertebrate host, an aquatic environment, and a mammalian host. We report a global transcriptional analysis of how this parasite alters gene regulation to adapt to three distinct environments. RESULTS Utilizing a genomic microarray made of 12,000 45-50-mer oligonucleotides based on expressed sequence tags, three different developmental stages of the schistosome parasite were analyzed by pair-wise comparisons of transcript hybridization signals. This analysis resulted in the identification of 1,154 developmentally enriched transcripts. CONCLUSION This study expands the repertoire of schistosome genes analyzed for stage-specific expression to over 70% of the predicted genome. Among the new associations identified are the roles of robust protein synthesis and programmed cell death in development of cercariae in the sporocyst stages, the relative paucity of cercarial gene expression outside of energy production, and the remarkable diversity of adult gene expression programs that reflect adaptation to the host bloodstream and an average lifespan that may approach 10 years.
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Affiliation(s)
- Emmitt R Jolly
- California Institute for Quantitative Biomedical Research (QB3) of the University of California, San Francisco, 4th Street, San Francisco, CA 94158 USA
| | - Chen-Shan Chin
- California Institute for Quantitative Biomedical Research (QB3) of the University of California, San Francisco, 4th Street, San Francisco, CA 94158 USA
| | - Steve Miller
- California Institute for Quantitative Biomedical Research (QB3) of the University of California, San Francisco, 4th Street, San Francisco, CA 94158 USA
| | - Mahmoud M Bahgat
- Theraputic Chemistry Department, Infectious Diseases and Immunology Laboratory, the Road to Nobel Project, the National Research Center, Dokki, 12311 Cairo, Egypt
| | - KC Lim
- California Institute for Quantitative Biomedical Research (QB3) of the University of California, San Francisco, 4th Street, San Francisco, CA 94158 USA
| | - Joseph DeRisi
- California Institute for Quantitative Biomedical Research (QB3) of the University of California, San Francisco, 4th Street, San Francisco, CA 94158 USA
| | - James H McKerrow
- California Institute for Quantitative Biomedical Research (QB3) of the University of California, San Francisco, 4th Street, San Francisco, CA 94158 USA
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Scott JC, McManus DP. Molecular cloning and enzymatic expression of the 28-kDa glutathione S-transferase of Schistosoma japonicum: evidence for sequence variation but lack of consistent vaccine efficacy in the murine host. Parasitol Int 2000; 49:289-300. [PMID: 11077263 DOI: 10.1016/s1383-5769(00)00058-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Glutathione S-transferases (GSTs) have long been regarded as attractive vaccine (and drug) targets in schistosomes due to their suspected role in detoxification processes. Indeed, the 28-kDa GST of Schistosoma mansoni (SmGST28) has proven efficacy as an antigen for protective immunity reducing worm burden, female fecundity and egg viability. In contrast, the vaccinating effects of the bacterial expressed homologue of Philippine S. japonicum (SjpGST28) have proved disappointing, possibly because this recombinant form was an incomplete sequence, lacking five N-terminal amino acids which may have affected its vaccination efficacy. Here we describe the cloning and functional enzymatic expression of a complete cDNA encoding SjpGST28. We report also on the immunogenicity and vaccine efficacy of this molecule as a purified recombinant protein and as a DNA plasmid vaccine in the murine model. We further describe the cloning of several complete cDNAs encoding the Chinese homologue of SjpGST28 and the identification of 3 SjcGST28 sequence variants which are probably encoded by distinct alleles.
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Affiliation(s)
- J C Scott
- Molecular Parasitology Unit, Australian Centre for International and Tropical Health and Nutrition, The University of Queensland, Post Office Royal Brisbane Hospital, Herston, Queensland 4029, Brisbane, Australia
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Production and characterization of glutathione-S-transferase fused with a poly-histidine tag. Enzyme Microb Technol 2000; 27:219-226. [PMID: 10899546 DOI: 10.1016/s0141-0229(00)00215-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Schistosoma japonicum glutathione-S-transferase (SjGST) was genetically engineered with a poly-histidine tag at the C-terminus and highly expressed in Escherichia coli. Both SjGST and the tagged protein, SjGST/His, were purified with glutathione Sepharose 4B gels and subsequently studied for their activities, antibody-binding abilities, and metal affinities. The production level of active SjGST/His was higher than that of SjGST. Both proteins had similar specific catalytic activities and binding abilities with anti-SjGST antibody, while the antibody against poly-histidine recognized only SjGST/His. Proteolytic degradation was occasionally observed in aged dialyzed SjGST/His preparation. Under a native condition, the Co(2+)-chelated TANOL gel (Co-TANOL) had a better binding specificity to the tagged protein than did the Ni(2+)-chelated nitriloacetic acid (Ni-NTA) agarose gel. However, the binding capacity of the Ni-NTA gel for SjGST/His was 2-fold higher than that of the Co-TANOL one. To increase the native binding specificity of the Ni-NTA gel, 20 mM imidazole had to be added to the washing solution. In a denatured state, both gels could only capture SjGST/His, and the binding capacity of the Ni-NTA gel was nearly 2-fold higher than that of the Co-TANOL gel. The binding association constants of both gels with SjGST/His did not differ greatly under either condition. The study demonstrated that the C-terminal addition of the poly-histidine tag to SjGST increased the metal affinity of the enzyme to the Co-TANOL gel under both native and denaturing conditions and to the Ni-NTA gel under denaturing conditions, whereas the enzymatic activity and antibody-binding ability were not affected.
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Zhang Y, Taylor MG, Bickle QD, Wang H, Ge J. Vaccination of mice with gamma-irradiated Schistosoma japonicum cercariae. Parasite Immunol 1999; 21:111-7. [PMID: 10101721 DOI: 10.1046/j.1365-3024.1999.00208.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
gamma-irradiated cercarial vaccines induce high levels of protection in mice against Schistosoma mansoni infection, however, the same has not been well established for S. japonicum. Here we describe vaccination studies in mice with gamma-irradiated S. japonicum cercariae testing the effectiveness of different irradiation doses, number of vaccinations, and mouse strains. In CBA/Ca mice, a single percutaneous exposure to 500 S. japonicum cercariae previously attenuated by 10, 20, 30, 40 or 50 krad gamma-irradiation induced significant, but comparable levels of protection (34-46%) against challenge infection. In a repeat experiment in C57Bl/6 mice, only groups vaccinated with 10 or 20 krad gamma-irradiated cercariae showed statistically significant, but lower levels of resistance (20-24%). Multiple vaccination of CBA/Ca mice with 500 20 krad gamma-irradiated cercariae did not improve the resistance level (40%). Analysis of IgG responses showed no clear correlation between antibody levels and levels of protection. Western blot analysis suggested that recognition of a 200-kDa antigen might be correlated with protection, that antigens of 42 and 50 kDa may be involved in the protection induced by single vaccination, but that different antigens might be protective in single vs multiple vaccinations. Sera from mice vaccinated with gamma-irradiated cercariae recognized many fewer antigens than more protective sera from mice vaccinated with UV-attenuated cercariae. These results suggest that the mouse may not be a suitable host for studies involving gamma-irradiated S. japonicum vaccines.
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Affiliation(s)
- Y Zhang
- Department of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, UK
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Abstract
Praziquantel is a synthetic drug with a remarkable activity against parasites, particularly treamatodes and cestodes. Initial genotoxicity tests used a spectrum of endpoints including tests in bacteria, yeasts, mammalian cells and Drosophila and each one gave negative results. Effects on reproductive cells of mice were negative as well. However, host mediated studies in mice and humans were contradictory and a comutagenic effect with several mutagens and carcinogens was found. Later studies, including monitoring in humans and pigs have shown that Praziquantel induces a greater frequency of hyperploid lymphocytes as well as structural chromosomal aberrations, but not in all the individuals treated. In vitro studies have demonstrated that Praziquantel can induce micronuclei in syrian hamster embryonic (SHE) cells and in lymphocytes of some individuals. The same was found about structural chromosomal aberrations. Fetal death and fetal resorption were found when Praziquantel was administered in high doses to pregnant rats between the 6th and 10th day of gestation. Due to its efficiency as a parasiticide, Praziquantel is in use in Latin-American, Asiatic, African and East-European countries where infections by trematodes and cestodes are frequent. However, the extensive use of Praziquantel in multiple reinfections, in non-infected and non-diagnosed individuals for prevention, in higher doses or repeated doses for cysticercosis treatment and in individuals exposed to environmental mutagens, in conjunction with new findings about its metabolism and genotoxic properties, make it necessary to further evaluate the potential of this drug not only to be mutagenic per se, but to contribute in the development of neoplasm.
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Affiliation(s)
- R Montero
- Departamento de Genética y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, UNAM, Mexico.
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Kalinna BH, McManus DP. A vaccine against the Asian schistosome, Schistosoma japonicum: an update on paramyosin as a target of protective immunity. Int J Parasitol 1997; 27:1213-9. [PMID: 9394192 DOI: 10.1016/s0020-7519(97)00119-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Paramyosin from parasitic worms of the genus Schistosoma has shown promise as a vaccine target and it is one of the candidates selected by WHO for the development of a vaccine against schistosomiasis. Here we discuss the literature of the past decade and report on different recombinant paramyosin constructs we are using in our laboratory to develop a vaccine against the Asian schistosoma, Schistosoma japonicum.
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Affiliation(s)
- B H Kalinna
- Molecular Parasitology Unit, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research, Bancroft Centre, Royal Brisbane Hospital, Australia.
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Yang W, Gobert GN, McManus DP. Oral vaccination of mice with recombinant Schistosoma japonicum proteins induces specific anti-parasite antibodies and damage to adult worms after a challenge infection. Int J Parasitol 1997; 27:843-53. [PMID: 9279589 DOI: 10.1016/s0020-7519(97)00053-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mucosal immunisation by the oral route represents a cheap and simple method for delivering protective antigens to a host against gastrointestinal and respiratory pathogens. In the case of schistosome (bloodfluke) worms, 2 life-cycle stages may be exposed to the host's mucosa; the larval schistosomulum is exposed to the respiratory mucosa and, depending on the species, the egg may come into contact with the intestinal or urinogenital mucosa. Both IgA and some Isotypes of IgG have been implicated in protective immunity against schistosomiasis in humans and in experimental animal models. We have used a novel approach to determine whether schistosome-specific antibodies and protective immunity could be generated in mice by oral administration of bacterial lysates containing recombinant Schistosoma japonicum proteins. The mice produced specific antibodies to paramyosin and GST26, 2 important vaccine candidates for schistosomiasis, but there was no significant reduction in worm burdens in groups of mice immunised with either protein. Significantly, however, transmission electron microscopy revealed damage to the teguments of adult female and male S. japonicum worms obtained from mice vaccinated with recombinant paramyosin; there was also extensive damage to the tegument of male worms recovered from mice vaccinated with recombinant GST26. Our observations that oral vaccination with bacterial lysates containing recombinant proteins induced particular classes and subclasses of circulating antibodies with resultant damage to the surface of adult worms may have important implications for the future development of oral vaccines against a systemic infection such as schistosomiasis.
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Affiliation(s)
- W Yang
- Molecular Parasitology Unit, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research, Herston, Brisbane, Australia
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Hope M, Duke M, McManus DP. A biological and immunological comparison of Chinese and Philippine Schistosoma japonicum. Int J Parasitol 1996; 26:325-32. [PMID: 8786224 DOI: 10.1016/0020-7519(95)00133-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A comparison was made of the host (BALB/c mice)-parasite relationship of a Chinese mainland (Anhui) strain and Philippine (Sorsogon) strain of Schistosoma japonicum. Differences in fecundity, infectivity, prepatency, host survival and susceptibility to praziquantel were examined. The mean percentage of worms establishing was 40.0 and 34.4% for Chinese and Philippine S. japonicum, respectively. Egg laying commenced on days 26 and 28 after infection with the Chinese or Philippine strain, respectively. Significant differences in the total number of eggs and number of eggs per worm pair laid were observed. In terms of the number of eggs per worm pair and host survival, the Chinese strain was more virulent than the Philippine in BALB/c mice. Praziquantel treatment reduced worm burdens by 80-90% in both strains. No significant differences were observed in murine antibody responses against the 2 strains. Irradiated Chinese cercarial vaccines were protective only against homologous challenge; irradiated Philippine cercarial vaccines were not protective, confirming earlier findings that this strain is neither able to induce nor able to act as a target of irradiated cercariae-mediated vaccination. Antibody responses and immunoblot profiles in vaccinated mice were similar, regardless of the strain of parasite used.
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Affiliation(s)
- M Hope
- Molecular Parasitology Unit, Queensland Institute of Medical Research, Brisbane, Australia
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Liu SX, Song GC, Xu YX, Yang W, McManus DP. Anti-fecundity immunity induced in pigs vaccinated with recombinant Schistosoma japonicum 26kDa glutathione-S-transferase. Parasite Immunol 1995; 17:355-40. [PMID: 8552408 DOI: 10.1111/j.1365-3024.1995.tb00900.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have recently reported (Liu et al. 1995) that immunization of mice with recombinant 26kDa GST (reSjc26GST) induces a pronounced anti-fecundity effect after experimental infection with Chinese Schistosoma japonicum. A similar vaccination trial was thus carried out on pigs, important reservoirs for schistosomiasis japonica, using purified, reSjc26GST and reSjp26GST from Schistosoma japonicum with alum as adjuvant; in general, similar results were obtained with the two sources of recombinant 26kDa GST. Some protection in terms of worm reduction, significant with males, against challenge infection was observed in vaccinated pigs. Moreover, prior to challenge, levels of specific anti-re26GST antibodies in the vaccinated pigs were significantly higher than in non-vaccinated pigs as determined by GST-ELISA. The most striking feature of the vaccine trial was the significant reduction in the number of eggs, especially mature eggs, in the livers of vaccinated animals. The results indicate that immunization with recombinant Sj26GST can provide some reduction in worm burden following exposure of pigs to reinfection with S. japonicum. In addition, reSj26GST can induce an anti-fecundity effect, thereby reducing pathology, coupled with a delay or interruption of the development of immature to mature eggs in the liver. As a consequence, vaccination with Sj26GST would also prove useful in affecting the transmission of schistosomiasis japonica.
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Affiliation(s)
- S X Liu
- Department of Immunology, Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine, Shanghai, People's Republic of China
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Pillai S, Dermody K, Metcalf B. Immunogenicity of genetically engineered glutathione S-transferase fusion proteins containing a T-cell epitope from diphtheria toxin. Infect Immun 1995; 63:1535-40. [PMID: 7534277 PMCID: PMC173186 DOI: 10.1128/iai.63.4.1535-1540.1995] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Glutathione S-transferase (GST) has been shown to induce a marginal antibody response in experimental animals as well as partial protection against a number of parasitic worms, including Schistosoma and Fasciola species. The objective of our study was to increase the immunogenicity of GST by adding heterologous T-cell epitopes at the carboxy terminus of the protein. We generated recombinant GST proteins by attaching one or three tandem repeats of a T-cell epitope of CRM197, a nontoxic variant of diphtheria toxin. This T-cell epitope encoding the region of amino acids 366 to 383 of CRM197, when contained in a GST fusion protein and/or after purification as a recombinant peptide, retained the ability to induce a CRM197-specific T-cell response. The fusion protein containing a single T-cell epitope induced a strong T-cell proliferative response to GST and also enhanced anti-GST antibody production in mice. The addition of three repeats of the epitope did not augment the responses when compared with the responses of GST itself. The results suggest that the addition of a single T-cell epitope to a larger protein like GST increases the immunogenicity of the protein.
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Affiliation(s)
- S Pillai
- Department of Immunology, Lederle-Praxis Biologicals Division, West Henrietta, New York 14586
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Yang W, Waine GJ, Becker M, Liu SX, McManus DP. The 26-kDa glutathione-S-transferases from Chinese and Philippine Schistosoma japonicum are identical. Acta Trop 1994; 57:345-9. [PMID: 7810392 DOI: 10.1016/0001-706x(94)90082-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- W Yang
- Molecular Parasitology Unit, Queensland Institute of Medical Research, Brisbane, Australia
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Dettman CD, Higgins-Opitz SB. The infection characteristics of the antelope schistosomes, Schistosoma margrebowiei and S. leiperi, in inbred BALB/c mice and in Mastomys coucha. J Helminthol 1994; 68:19-33. [PMID: 8006380 DOI: 10.1017/s0022149x00013420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Detailed studies were carried out to assess the infection characteristics of the antelope schistosomes in BALB/c mice and Mastomys coucha. Both schistosome species reached sexual maturity in these hosts. However, they differed markedly in terms of egg production rates and preferred sites of tissue egg deposition. Tissue egg deposition commenced between 4 and 5 weeks in the case of Schistosoma margrebowiei and between 6 and 7 weeks in the case of S. leiperi. Tissue egg accumulation rates of S. leiperi were calculated to be 334 and 311 eggs/gravid worm pair/day in mice and M. coucha, respectively. The fecundity of S. margrebowiei was found to be substantially greater (approximately 5 times; daily output ranging from 1600-1900 eggs/gravid worm pair). While S. leiperi infections remained relatively stable in both hosts during the study period (i.e. up to 15 weeks after onset of egg laying), S. margrebowiei infections were observed to deteriorate rapidly in M. coucha.
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Affiliation(s)
- C D Dettman
- Department of Biology, University of Natal, Durban, Republic of South Africa
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Akhiani AA, Nilsson LA, Ouchterlony O. Effect of cholera toxin on vaccine-induced immunity and infection in murine schistosomiasis mansoni. Infect Immun 1993; 61:4919-24. [PMID: 8406897 PMCID: PMC281257 DOI: 10.1128/iai.61.11.4919-4924.1993] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Intradermal vaccination of mice with soluble adult worm antigen (SWAP) in combination with Mycobacterium bovis BCG (Swedish strain) induced significant protection against subsequent infection with Schistosoma mansoni cercariae. When cholera toxin (CT) was used as an adjuvant in combination with SWAP or fraction A, no significant protection was observed. However, intradermal vaccination in combination with CT triggered a strong anti-SWAP antibody response and induced a strong delayed-type hypersensitivity response to schistosome antigens (SWAP or fraction A), one significantly higher than that in the SWAP-BCG group. In addition, vaccinating mice intranasally with SWAP or cercarial antigen together with CT as adjuvant failed to induce any significant protection. Surprisingly, mice given CT alone intranasally revealed a significantly enhanced worm burden. These findings suggest that mucosal application of CT may modulate the host-parasite relationship in favor of parasite survival.
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Affiliation(s)
- A A Akhiani
- Department of Medical Microbiology and Immunology, University of Göteborg, Sweden
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18
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Abstract
It is now recognised that intraspecific variation is widespread in the human schistosome species. This review evaluates recent advances in the detection and characterisation of variants within the human schistosomes and the implications of this variation in terms of infectivity and development in intermediate and definitive hosts, drug responsiveness, pathogenicity and immunogenicity. It also examines advances in the methods used to detect variation and highlights the use of genetic approaches, notably enzyme electrophoresis and, especially, the recent application of DNA methods. Molecular techniques, such as restriction fragment length polymorphism (RFLP) analysis, polymerase chain reaction (PCR) and DNA sequencing are now proving invaluable for distinguishing species and strains of schistosomes and recent progress in this remarkably dynamic area is emphasised.
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Affiliation(s)
- D P McManus
- Molecular Helminthology Laboratory, Queensland Institute of Medical Research, Brisbane, Australia
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19
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Affiliation(s)
- N C Smith
- Institut für Parasitologie, Universität Zürich, Switzerland
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