1
|
Specific Antibodies and Arachidonic Acid Mediate the Protection Induced by the Schistosoma mansoni Cysteine Peptidase-Based Vaccine in Mice. Vaccines (Basel) 2020; 8:vaccines8040682. [PMID: 33207535 PMCID: PMC7712720 DOI: 10.3390/vaccines8040682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/29/2020] [Accepted: 11/04/2020] [Indexed: 12/20/2022] Open
Abstract
Several reports have documented the reproducible and considerable efficacy of the cysteine peptidase-based schistosomiasis vaccine in the protection of mice and hamsters against infection with Schistosoma mansoni and Schistosomahaematobium, respectively. Here, we attempt to identify and define the protection mechanism(s) of the vaccine in the outbred CD-1 mice-S. mansoni model. Mice were percutaneously exposed to S. mansoni cercariae following immunization twice with 0 or 10 μg S. mansoni recombinant cathepsin B1 (SmCB1) or L3 (SmCL3). They were examined at specified intervals post infection (pi) for the level of serum antibodies, uric acid, which amplifies type 2 immune responses and is an anti-oxidant, lipids, in particular, arachidonic acid (ARA), which is an endoschistosomicide and ovocide, as well as uric acid and ARA in the lung and liver. Memory IgG1, IgG2a, and IgG2b antibodies to the cysteine peptidase immunogen were detectable at and following day 17 pi. Serum, lung, and liver uric acid levels in immunized mice were higher than in naïve and unimmunized mice, likely as a consequence of cysteine peptidase-mediated catabolic activity. Increased circulating uric acid in cysteine peptidase-immunized mice was associated with elevation in the amount of ARA in lung and liver at every test interval, and in serum starting at day 17 pi. Together, the results suggest the collaboration of humoral antibodies and ARA schistosomicidal potential in the attrition of challenge S. mansoni (p < 0.0005) at the liver stage, and ARA direct parasite egg killing (p < 0.005). The anti-oxidant and reactive oxygen species-scavenger properties of uric acid may be responsible for the cysteine peptidase vaccine protection ceiling. This article represents a step towards clarifying the protection mechanism of the cysteine peptidase-based schistosomiasis vaccine.
Collapse
|
2
|
Liu C, Zhang YS, Chen F, Wu XY, Zhang BB, Wu ZD, Lei JX. Immunopathology in schistosomiasis is regulated by TLR2,4- and IFN-γ-activated MSC through modulating Th1/Th2 responses. Stem Cell Res Ther 2020; 11:217. [PMID: 32503644 PMCID: PMC7275460 DOI: 10.1186/s13287-020-01735-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 05/02/2020] [Accepted: 05/18/2020] [Indexed: 01/14/2023] Open
Abstract
Background and aims A marked egg-induced CD4+ T cell programmed inflammation and subsequent hepatic fibrosis characterize the pathogenesis of schistosomiasis. Mesenchymal stem cell (MSC) has been extensively studied for the treatment of schistosomiasis. However, the mechanism by which MSCs modulate the pathogenesis of schistosomiasis has not been clarified. Furthermore, the local inflammatory milieu may greatly influence the immunoregulatory properties of MSCs, and our early experiments demonstrated that Toll-like receptor (TLR)2/TLR4 agonist effected immune modulation of MSC. Here, we further investigated their modulation on the pathogenesis of schistosomiasis. Methods Adult BALB/c male mice were percutaneously infected with 16 ± 2 pairs S. japonicum cercariae and received intravenously pretreated MSC at 1 week and 3 weeks post-infection, respectively. At 8 weeks post-infection, effects of MSC on liver histology were shown by hematoxylin and eosin (H&E) staining and Masson staining and quantitatively compared by the hepatic hydroxyproline content; α-smooth muscle actin (α-SMA), collagen type I(Col-1), transforming growth factor β (TGF-β), and tumor necrosis factor-α (TNF-α) gene expression in the liver were assessed by semi-quantitative polymerase chain reaction (PCR); the Th1/Th2 dominance among different groups was compared by analyzing CD4+ interferon-γ (IFN-γ)+ and CD4+interleukin-4 (IL-4)+T cells in the liver by flow cytometry and serum level of IFN-γ and IL-5 using enzyme-linked immunosorbent assay (ELISA). Effects of different kinds of MSC were further evaluated in vitro by the coculture system. Results Results showed TLR4- and IFN-γ-activated MSC alleviated liver fibrosis in infected mice, without a significant increase of mortality, and unpretreated MSC showed no clear improvement; however, TLR2- and IFN-γ-activated MSC displayed aggravated immunopathology. In accord with the pathological results, TLR4- and IFN-γ-activated MSC groups showed moderate enhancement of Th1 response in vitro and clear Th1 dominance in vivo without leading to extreme inflammation, whereas TLR2- and IFN-γ-activated MSC not only induced Th1 response, but also triggered excessive inflammation as evidenced by atrophy of the thymus and higher TNF level in the coculture system. Conclusions This study demonstrates that TLR4 combined with IFN-γ can activate the MSC group with positive effects on the pathology of schistosomiasis by modulating Th subsets at some degree. This result suggests that when MSC is being used to treat different immuno-disturbance complications, subtle pretreatment methods should be seriously considered.
Collapse
Affiliation(s)
- Chao Liu
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yi-Shu Zhang
- Department of Parasitology of Guilin Medical University, Guilin, China
| | - Fang Chen
- School of Medicine, South China University of Technology, Guangzhou, China
| | - Xiao-Ying Wu
- The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Bei-Bei Zhang
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Zhong-Dao Wu
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jun-Xia Lei
- School of Medicine, South China University of Technology, Guangzhou, China.
| |
Collapse
|
3
|
Mbanefo EC, Fu CL, Ho CP, Le L, Ishida K, Hammam O, Hsieh MH. Interleukin-4 Signaling Plays a Major Role in Urogenital Schistosomiasis-Associated Bladder Pathogenesis. Infect Immun 2020; 88:e00669-19. [PMID: 31843965 PMCID: PMC7035943 DOI: 10.1128/iai.00669-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 11/26/2019] [Indexed: 11/20/2022] Open
Abstract
Interleukin-4 (IL-4) is crucial in many helminth infections, but its role in urogenital schistosomiasis, infection with Schistosoma haematobium worms, remains poorly understood due to a historical lack of animal models. The bladder pathology of urogenital schistosomiasis is caused by immune responses to eggs deposited in the bladder wall. A range of pathology occurs, including urothelial hyperplasia and cancer, but associated mechanisms and links to IL-4 are largely unknown. We modeled urogenital schistosomiasis by injecting the bladder walls of IL-4 receptor-alpha knockout (Il4ra-/- ) and wild-type mice with S. haematobium eggs. Readouts included bladder histology and ex vivo assessments of urothelial proliferation, cell cycle, and ploidy status. We also quantified the effects of exogenous IL-4 on urothelial cell proliferation in vitro, including cell cycle status and phosphorylation patterns of major downstream regulators in the IL-4 signaling pathway. There was a significant decrease in the intensity of granulomatous responses to bladder-wall-injected S. haematobium eggs in Il4ra-/- versus wild-type mice. S. haematobium egg injection triggered significant urothelial proliferation, including evidence of urothelial hyper-diploidy and cell cycle skewing in wild-type but not Il4ra-/- mice. Urothelial exposure to IL-4 in vitro led to cell cycle polarization and increased phosphorylation of AKT. Our results show that IL-4 signaling is required for key pathogenic features of urogenital schistosomiasis and that particular aspects of this signaling pathway may exert these effects directly on the urothelium. These findings point to potential mechanisms by which urogenital schistosomiasis promotes bladder carcinogenesis.
Collapse
Affiliation(s)
- Evaristus C Mbanefo
- Division of Urology, Children's National Medical Center, Washington, DC, USA
- Bladder Immunology Group, Biomedical Research Institute, Rockville, Maryland, USA
| | - Chi-Ling Fu
- Stanford University School of Medicine, Stanford, California, USA
| | - Christina P Ho
- Division of Urology, Children's National Medical Center, Washington, DC, USA
| | - Loc Le
- Bladder Immunology Group, Biomedical Research Institute, Rockville, Maryland, USA
- Center for Tropical Medicine and Infectious Diseases, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Kenji Ishida
- Bladder Immunology Group, Biomedical Research Institute, Rockville, Maryland, USA
| | | | - Michael H Hsieh
- Division of Urology, Children's National Medical Center, Washington, DC, USA
- Bladder Immunology Group, Biomedical Research Institute, Rockville, Maryland, USA
- Department of Urology, The George Washington University, Washington, DC, USA
| |
Collapse
|
4
|
Tebeje BM, Harvie M, You H, Loukas A, McManus DP. Schistosomiasis vaccines: where do we stand? Parasit Vectors 2016; 9:528. [PMID: 27716365 PMCID: PMC5045607 DOI: 10.1186/s13071-016-1799-4] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/14/2016] [Indexed: 12/20/2022] Open
Abstract
Schistosomiasis, caused mainly by S. mansoni, S. haematobium and S. japonicum, continues to be a serious tropical disease and public health problem resulting in an unacceptably high level of morbidity in countries where it is endemic. Praziquantel, the only drug currently available for treatment, is unable to kill developing schistosomes, it does not prevent re-infection and its continued extensive use may result in the future emergence of drug-resistant parasites. This scenario provides impetus for the development and deployment of anti-schistosome vaccines to be used as part of an integrated approach for the prevention, control and eventual elimination of schistosomiasis. This review considers the present status of candidate vaccines for schistosomiasis, and provides some insight on future vaccine discovery and design.
Collapse
Affiliation(s)
- Biniam Mathewos Tebeje
- QIMR Berghofer Medical Research Institute, Brisbane, Australia. .,School of Public Health, University of Queensland, Brisbane, Australia. .,Department of Immunology and Molecular Biology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
| | - Marina Harvie
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Hong You
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | | |
Collapse
|
5
|
Nawaratna SSK, Gobert GN, Willis C, Mulvenna J, Hofmann A, McManus DP, Jones MK. Lysosome-associated membrane glycoprotein (LAMP)--preliminary study on a hidden antigen target for vaccination against schistosomiasis. Sci Rep 2015; 5:15069. [PMID: 26472258 PMCID: PMC4607944 DOI: 10.1038/srep15069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 08/13/2015] [Indexed: 12/12/2022] Open
Abstract
Our previously reported gene atlasing of schistosome tissues revealed transcripts that were highly enriched in the digestive tract of Schistosoma mansoni. From these, we selected two candidates, Sm-LAMP and Sm-NPC2 for testing as vaccine targets. The two molecules were selected on the basis of relatively high expression in the gastrodermis, their potentially important biological function, divergence from homologous molecules of the host and possible apical membrane expression in the gastrodermis. Bacterially expressed recombinant peptides corresponding to regions excluding trans-membrane domains of the selected vaccine targets were used in blinded vaccine trials in CBA mice using alum-CpG as adjuvant. Vaccine trials using the recombinant insoluble Sm-LAMP protein showed 16-25% significant reduction in total worm burden. Faecal egg count reduction was 52% and 60% in two trials, respectively, with similar results for the solubly expressed protein. Liver egg burden was reduced significantly (20% and 38%) with an insoluble recombinant Sm-LAMP in two trials, but not with the soluble recombinant form. Parasite fecundity was not affected by either Sm-LAMP protein preparations in the trials. It is concluded that Sm-LAMP may provide limited protection towards S. mansoni infections but could be used in combination with other vaccine candidates, to provide more comprehensive protection.
Collapse
Affiliation(s)
- Sujeevi S. K. Nawaratna
- School of Veterinary Sciences, The University of Queensland, Gatton Campus, Gatton Qld, 4343, Australia
- QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Qld, 4006, Australia
| | - Geoffrey N. Gobert
- QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Qld, 4006, Australia
| | - Charlene Willis
- QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Qld, 4006, Australia
| | - Jason Mulvenna
- QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Qld, 4006, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Qld 4111, Australia
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Donald P. McManus
- QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Qld, 4006, Australia
| | - Malcolm K. Jones
- School of Veterinary Sciences, The University of Queensland, Gatton Campus, Gatton Qld, 4343, Australia
- QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Qld, 4006, Australia
| |
Collapse
|
6
|
Gong W, Huang F, Ma Y, Bai H, Yin L, Li J, Chen C, Xu X, Chen XP. Protective immunity against Schistosoma japonicum infection can be provided by IgG antibodies towards periodate-sensitive or periodate-resistant glycans. Parasit Vectors 2015; 8:234. [PMID: 25907161 PMCID: PMC4408597 DOI: 10.1186/s13071-015-0842-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/03/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It has been well accepted that glycans present in schistosomes are highly antigenic. However, it is not clear what kind of worm glycans can affect the infected host to mount IgG responses and whether mounted anti-glycan IgG responses are protective. METHODS The contribution of antigenicity by glycans was measured by using competitive ELISA assay in sera from infected mice and humans. Monoclonal antibodies towards soluble Schistosoma japonicum egg antigens (SjEA) were generated from SjEA immunizated mice. The expression of glycans on surfaces of cercaria or young worm and their distributions were examined by immunofluorescence assay. The protective roles of glycans-specific mAbs were assayed by determination of the worm and egg burden in infected mice. RESULTS Both periodate-resistant glycans and periodate-sensitive glycans are antigenic in schistosome infections. When monoclonal antibodies against either periodate-sensitive or periodate-resistant glycans were administered prior to schistosome infections in mice, both kinds of anti-glycan antibodies were found to successfully provide protective immunity to infected mice. CONCLUSIONS Both periodate-resistant and periodate-sensitive glycans are antigenic, and dominant anti-glycan IgG responses can play important roles in protective immunity in schistosome infected hosts.
Collapse
Affiliation(s)
- Wenci Gong
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Fengjuan Huang
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Yilei Ma
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Hongmei Bai
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Lan Yin
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Jun Li
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Chunxia Chen
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| | - Xindong Xu
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China.
| | - Xiao-Ping Chen
- Department of Immunology, Tongji University School of Medicine, Shanghai, China.
| |
Collapse
|
7
|
Mbanefo EC, Kumagai T, Kodama Y, Kurosaki T, Furushima-Shimogawara R, Cherif MS, Mizukami S, Kikuchi M, Huy NT, Ohta N, Sasaki H, Hirayama K. Immunogenicity and anti-fecundity effect of nanoparticle coated glutathione S-transferase (SjGST) DNA vaccine against murine Schistosoma japonicum infection. Parasitol Int 2015; 64:24-31. [PMID: 25603531 DOI: 10.1016/j.parint.2015.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/10/2014] [Accepted: 01/11/2015] [Indexed: 01/10/2023]
Abstract
There is still urgent need for a vaccine against schistosomiasis, especially in Schistosoma japonicum endemic areas where even a vaccine that will interrupt zoonotic transmission will be potentially effective as an intervention tool. We had developed a novel nanoparticle gene delivery system, which has proven efficacious in gene transfection to target immune cells with complementary adjuvant effect and high protective efficacy in several diseases. Here, we applied this nanoparticle system in combination with S. japonicum glutathione S-transferase (SjGST) DNA vaccine to show the immunogenicity and anti-fecundity effect of the nanoparticle coated vaccine formulation against murine schistosomiasis. The nanoparticle-coated DNA vaccine formulation induced desired immune responses. In comparison with the nanoparticle coated empty vector, it produced significantly increased antigen-specific humoral response, T-helper 1 polarized cytokine environment, higher proportion of IFN-γ producing CD4(+) T-cells and the concomitant decrease in IL-4 producing CD4(+) T-cells. Although there was no effect on worm burden, we recorded a marked reduction in tissue egg burden. There was up to 71.3% decrease in tissue egg burden and 55% reduction in the fecundity of female adult worms. Our data showed that SjGST DNA vaccine, delivered using the nanoparticle gene delivery system, produced anti-fecundity effect on female adult schistosomes as previously described by using conventional subunit vaccine with adjuvant, proving this DNA vaccine formulation as a promising candidate for anti-pathology and transmission blocking application.
Collapse
Affiliation(s)
- Evaristus Chibunna Mbanefo
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN) and Global COE Program, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Department of Parasitology and Entomology, Faculty of Bioscience, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Nigeria
| | - Takashi Kumagai
- Section of Environmental Parasitology, Tokyo Medical and Dental University Graduate School of Medical and Dental Science, 113-8519, Japan
| | - Yukinobu Kodama
- Department of Hospital Pharmacy, Nagasaki University Hospital, 1-7-1 Sakamoto, 852-8501, Japan
| | - Tomoaki Kurosaki
- Department of Hospital Pharmacy, Nagasaki University Hospital, 1-7-1 Sakamoto, 852-8501, Japan
| | - Rieko Furushima-Shimogawara
- Section of Environmental Parasitology, Tokyo Medical and Dental University Graduate School of Medical and Dental Science, 113-8519, Japan
| | - Mahamoud Sama Cherif
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN) and Global COE Program, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan
| | - Shusaku Mizukami
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN) and Global COE Program, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan
| | - Mihoko Kikuchi
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN) and Global COE Program, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan
| | - Nguyen Tien Huy
- Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Department of Clinical Product Development, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan
| | - Nobuo Ohta
- Section of Environmental Parasitology, Tokyo Medical and Dental University Graduate School of Medical and Dental Science, 113-8519, Japan
| | - Hitoshi Sasaki
- Department of Hospital Pharmacy, Nagasaki University Hospital, 1-7-1 Sakamoto, 852-8501, Japan
| | - Kenji Hirayama
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN) and Global COE Program, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan; Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, 852-8523, Japan.
| |
Collapse
|
8
|
Mbanefo EC, Huy NT, Wadagni AA, Eneanya CI, Nwaorgu O, Hirayama K. Host determinants of reinfection with schistosomes in humans: a systematic review and meta-analysis. PLoS Negl Trop Dis 2014; 8:e3164. [PMID: 25211227 PMCID: PMC4161334 DOI: 10.1371/journal.pntd.0003164] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 08/04/2014] [Indexed: 12/12/2022] Open
Abstract
Background Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel) for this disease, reinfection occurs rapidly after mass drug administration (MDA). Because the entire population do not get reinfected at the same rate, it is possible that host factors may play a dominant role in determining resistance or susceptibility to reinfection with schistosomes. Here, we systematically reviewed and meta-analyzed studies that reported associations between reinfection with the principal human-infecting species (S. mansoni, S. japonicum and S. haematobium) and host socio-demographic, epidemiological, immunological and genetic factors. Methodology/Principal Findings PubMed, Scopus, Google Scholar, Cochrane Review Library and African Journals Online public databases were searched in October 2013 to retrieve studies assessing association of host factors with reinfection with schistosomes. Meta-analysis was performed to generate pooled odds ratios and standardized mean differences as overall effect estimates for dichotomous and continuous variables, respectively. Quality assessment of included studies, heterogeneity between studies and publication bias were also assessed. Out of the initial 2739 records, 109 studies were included in the analyses, of which only 32 studies with 37 data sets were eligible for quantitative data synthesis. Among several host factors identified, strong positive association was found with age and pre-treatment intensity, and only slightly for gender. These factors are major determinants of exposure and disease transmission. Significant positive association was found with anti-SWA IgG4 level, and a negative overall effect for association with IgE levels. This reconfirmed the concept that IgE/IgG4 balance is a major determinant of protective immunity against schistosomiasis. Other identified determinants were reported by a small number of studies to enable interpretation. Conclusions Our data contribute to the understanding of host-parasite interaction as it affects reinfection, and is a potential tool to guide planning and tailoring of community interventions to target high-risk groups. One of the major challenges of schistosomiasis control is that disease prevalence reverts to baseline levels after mass drug administration due to high rate of reinfection. Host factors play a major role in determining resistance or susceptibility to reinfection with schistosomiasis and other diseases. We systematically searched and analyzed studies that identified potential host determinants of reinfection with schistosomes. Among demographic variables, age but not gender was strongly associated with reinfection with schistosomes. Pretreatment infection intensity was also identified as a major determinant of reinfection. Positive association with IgG4 levels and negative association with IgE levels reconfirmed the notion that IgE/IgG4 balance is the major factor controlling protective immunity against schistosomiasis. Other factors were reported by few studies to allow correct inferences. These results contribute to our understanding of host-parasite relationship as it affects reinfection, and will be useful for planning and targeting the limited resources for intervention on high-risk groups.
Collapse
Affiliation(s)
- Evaristus Chibunna Mbanefo
- Department of Parasitology and Entomology, Faculty of Bioscience, Nnamdi Azikiwe University, Awka, Nigeria
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
- * E-mail: ,
| | - Nguyen Tien Huy
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Anita Akpeedje Wadagni
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Christine Ifeoma Eneanya
- Department of Parasitology and Entomology, Faculty of Bioscience, Nnamdi Azikiwe University, Awka, Nigeria
| | - Obioma Nwaorgu
- Department of Parasitology and Entomology, Faculty of Bioscience, Nnamdi Azikiwe University, Awka, Nigeria
| | - Kenji Hirayama
- Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| |
Collapse
|
9
|
Stephenson R, You H, McManus DP, Toth I. Schistosome Vaccine Adjuvants in Preclinical and Clinical Research. Vaccines (Basel) 2014; 2:654-85. [PMID: 26344751 PMCID: PMC4494218 DOI: 10.3390/vaccines2030654] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/08/2014] [Accepted: 08/15/2014] [Indexed: 12/16/2022] Open
Abstract
There is currently no vaccine available for human use for any parasitic infections, including the helminth disease, schistosomiasis. Despite many researchers working towards this goal, one of the focuses has been on identifying new antigenic targets. The bar to achieve protective efficacy in humans was set at a consistent induction of 40% protection or better by the World Health Organisation (WHO), and although this is a modest goal, it is yet to be reached with the six most promising schistosomiasis vaccine candidates (Sm28GST, IrV5, Sm14, paramyosin, TPI, and Sm23). Adjuvant selection has a large impact on the effectiveness of the vaccine, and the use of adjuvants to aid in the stimulation of the immune system is a critical step and a major variable affecting vaccine development. In addition to a comprehensive understanding of the immune system, level of protection and the desired immune response required, there is also a need for a standardised and effective adjuvant formulation. This review summarises the status of adjuvants that have been or are being employed in schistosomiasis vaccine development focusing on immunisation outcomes at preclinical and clinical stages.
Collapse
Affiliation(s)
- Rachel Stephenson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
| | - Hong You
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Queensland Q4006, Australia.
| | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Queensland Q4006, Australia.
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia.
| |
Collapse
|
10
|
El Ridi R, Tallima H, Dalton JP, Donnelly S. Induction of protective immune responses against schistosomiasis using functionally active cysteine peptidases. Front Genet 2014; 5:119. [PMID: 24847355 PMCID: PMC4021144 DOI: 10.3389/fgene.2014.00119] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 04/17/2014] [Indexed: 01/08/2023] Open
Abstract
Each year schistosomiasis afflicts up to 600 million people in 74 tropical and sub-tropical countries, predominantly in the developing world. Yet we depend on a single drug, praziquantel, for its treatment and control. There is no vaccine available but one is urgently needed especially since praziquantel-resistant parasites are likely to emerge at some time in the future. The disease is caused by several worm species of the genus Schistosoma. These express several classes of papain-like cysteine peptidases, cathepsins B and L, in various tissues but particularly in their gastrodermis where they employ them as digestive enzymes. We have shown that sub-cutaneous injection of recombinant and functionally active Schistosoma mansoni cathepsin B1 (SmCB1), or a cathepsin L from a related parasite Fasciola hepatica (FhCL1), elicits highly significant protection (up to 73%) against an experimental challenge worm infection in murine models of schistosomiasis. The immune modulating properties of this subcutaneous injection can boost protection levels (up to 83%) when combined with other S. mansoni vaccine candidates, glyceraldehyde 3-phosphate dehydrogenase (SG3PDH) and peroxiredoxin (PRX-MAP). Here, we discuss these data in the context of the parasite's biology and development, and provide putative mechanism by which the native-like cysteine peptidase induce protective immune responses.
Collapse
Affiliation(s)
- Rashika El Ridi
- Zoology Department, Faculty of Science, Cairo University Cairo, Egypt
| | - Hatem Tallima
- Zoology Department, Faculty of Science, Cairo University Cairo, Egypt
| | - John P Dalton
- Medical Biology Centre, School of Biological Sciences, Queen's University Belfast Belfast, Northern Ireland
| | - Sheila Donnelly
- The i-three Institute, University of Technology at Sydney Ultimo, Sydney, NSW, Australia
| |
Collapse
|
11
|
Cruz LJ, Rueda F, Simón L, Cordobilla B, Albericio F, Domingo JC. Liposomes containing NY-ESO-1/tetanus toxoid and adjuvant peptides targeted to human dendritic cells via the Fc receptor for cancer vaccines. Nanomedicine (Lond) 2014; 9:435-49. [DOI: 10.2217/nnm.13.66] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Aim: To improve the immunological response against tumors, a vaccine based on nanoliposomes targeted to the Fcγ-receptor was developed to enhance the immunogenicity of tumor-associated antigens (TAAs). Materials & methods: Using human dendritic cells in vitro, a fragment of the TAA NY-ESO-1 combined with a T-helper peptide from the tetanus toxoid encapsulated in nanoliposomes was evaluated. In addition, peptides Palm-IL-1 and MAP-IFN-γwere coadministered as adjuvants to enhance the immunological response. Results: Coadministration of Palm-IL-1 or MAP-IFN-γpeptide adjuvants and the hybrid NY-ESO-1-tetanus toxoid (soluble or encapsulated in nanoliposomes without targeting) increased immunogenicity. However, the most potent immunological response was obtained when the peptide adjuvants were encapsulated in liposomes targeted to human dendritic cells via the Fc receptor. Conclusion: This targeted vaccine strategy is a promising tool to activate and deliver antigens to dendritic cells, thus improving immunotherapeutic response in situations in which the immune system is frequently compromised, as in advanced cancers.
Collapse
Affiliation(s)
- Luis J Cruz
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials & Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Felix Rueda
- Department of Biochemistry & Molecular Biology, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain
| | - Lorena Simón
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials & Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Begoña Cordobilla
- Department of Biochemistry & Molecular Biology, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain
| | - Fernando Albericio
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials & Nanomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Organic Chemistry, University of Barcelona, Marti i Franques 1, 08028-Barcelona, Spain
- School of Chemistry, University of KwaZulu Natal, Durban, Kwa-Zulu Natal, 4000, South Africa
| | - Joan C Domingo
- Department of Biochemistry & Molecular Biology, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain
| |
Collapse
|
12
|
Tu Y, Hu Y, Fan G, Chen Z, Liu L, Man D, Liu S, Tang C, Zhang Y, Dai W. Protective effects of membrane-anchored and secreted DNA vaccines encoding fatty acid-binding protein and glutathione S-transferase against Schistosoma japonicum. PLoS One 2014; 9:e86575. [PMID: 24466157 PMCID: PMC3900569 DOI: 10.1371/journal.pone.0086575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 12/12/2013] [Indexed: 01/09/2023] Open
Abstract
In order to explore the high performance bivalent DNA-based vaccine against schistosomes, SjFABP and Sj26GST were selected and used to construct a vaccine. Two strategies were used to construct the bivalent DNA vaccine. In the first strategy, a plasmid encoding antigen in the secreted form was used, while in the other, a plasmid encoding a truncated form of SjFABP and Sj26GST targeted to the cell surface was used. Various parameters, including antibody and cytokine response, proliferation, histopathological examination, and characterization of T cell subsets were used to evaluate the type of immune response and the level of protection against challenge infection. Injection with secreted pIRES-sjFABP-sj26GST significantly increased the levels of antibody, splenocyte proliferation, and production of IFN-γ, compared with membrane-anchored groups. Analysis of splenic T cell subsets showed that the secreted vaccine significantly increased the percentage of CD3+CD4+ and CD3+CD8+ T cells. Liver immunopathology (size of liver granulomas) was significantly reduced in the secreted group compared with the membrane-anchored groups. Moreover, challenge experiments showed that the worm and egg burdens were significantly reduced in animals immunized with recombinant vaccines. Most importantly, secreted Sj26GST-SjFABP markedly enhanced protection, by reducing worm and egg burdens by 31.8% and 24.78%, respectively, while the membrane-anchored group decreased worm and egg burdens by 24.80% and 18.80%, respectively. Taken together, these findings suggest that the secretory vaccine is more promising than the membrane-anchored vaccine, and provides support for the development and application of this vaccine.
Collapse
Affiliation(s)
- Yaqin Tu
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yang Hu
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- * E-mail: (WD); (YH)
| | - Guorun Fan
- Department of Otorhinolaryngology, Union Hospital of Tongji Medical College, Huazhong Science and Technology University, Wuhan, Hubei, China
| | - Zhihao Chen
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lin Liu
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Dandan Man
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shuojie Liu
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Chengwu Tang
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yin Zhang
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Wuxing Dai
- Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- * E-mail: (WD); (YH)
| |
Collapse
|
13
|
Cysteine peptidases as schistosomiasis vaccines with inbuilt adjuvanticity. PLoS One 2014; 9:e85401. [PMID: 24465551 PMCID: PMC3897446 DOI: 10.1371/journal.pone.0085401] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 12/04/2013] [Indexed: 01/03/2023] Open
Abstract
Schistosomiasis is caused by several worm species of the genus Schistosoma and afflicts up to 600 million people in 74 tropical and sub-tropical countries in the developing world. Present disease control depends on treatment with the only available drug praziquantel. No vaccine exists despite the intense search for molecular candidates and adjuvant formulations over the last three decades. Cysteine peptidases such as papain and Der p 1 are well known environmental allergens that sensitize the immune system driving potent Th2-responses. Recently, we showed that the administration of active papain to mice induced significant protection (P<0.02, 50%) against an experimental challenge infection with Schistosoma mansoni. Since schistosomes express and secrete papain-like cysteine peptidases we reasoned that these could be employed as vaccines with inbuilt adjuvanticity to protect against these parasites. Here we demonstrate that sub-cutaneous injection of functionally active S. mansoni cathepsin B1 (SmCB1), or a cathepsin L from a related parasite Fasciola hepatica (FhCL1), elicits highly significant (P<0.0001) protection (up to 73%) against an experimental challenge worm infection. Protection and reduction in worm egg burden were further increased (up to 83%) when the cysteine peptidases were combined with other S. mansoni vaccine candidates, glyceraldehyde 3-phosphate dehydrogenase (SG3PDH) and peroxiredoxin (PRX-MAP), without the need to add chemical adjuvants. These studies demonstrate the capacity of helminth cysteine peptidases to behave simultaneously as immunogens and adjuvants, and offer an innovative approach towards developing schistosomiasis vaccines
Collapse
|
14
|
Li J, Zhuang W, Cong L, Shi W, Cai X, Huang F, Liao Y, Liu Y, Li J, Chen C, Chen XP. Cyclophilin A from Schistosoma japonicum promotes a Th2 response in mice. Parasit Vectors 2013; 6:330. [PMID: 24238088 PMCID: PMC3843525 DOI: 10.1186/1756-3305-6-330] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 11/14/2013] [Indexed: 12/30/2022] Open
Abstract
Background Schistosomiasis is a chronic infection, where the host immune response to the parasite changes from a predominantly Th1 to Th2 phenotype, when parasite enters the egg stage, restraining the host inflammatory immune responses to achieve a longer survival in the host. On the other hand, the development of Th2 responses causes immunopathological changes such as liver fibrosis. Therefore identification of schistosome-derived Th2 inducing molecules is important in the understanding of pathogenesis of schistosomiasis. A cyclophilin A homologue of Schistosoma japonicum was reported to be an egg-stage specific antigen, but its immunogenicity and immunoregulatory activities remain unknown. Methods We cloned and expressed the gene of cyclophilin A from Schistosoma japonicum (AY814078), named as SjCyP18 based on its molecular weight. The expression profiles in different stages of S. japonicum were examined by RT-PCR and immunofluorescence assay. The immunogenicity of SjCyP18 was measured by the presence of IgG in the sera from S. japonicum infected patients and animals, and the Th2-promting activities were examined by the subclass of immunoglobulins against SjCyP18 and by the IL-4 induction in T cells following footpad injection of SjCyP18. Results The cloned SjCyP18 has 65% homology with human or mouse cyclophilin A at the amino acid level. In contrast to reports as an egg-stage specific antigen, the gene was found to be expressed in all stages of S. japonicum. IgG responses against SjCyP18 were found in some S. japonicum infected patients and were significantly induced when infection become patent and produce eggs in infected mice. Furthermore, the Th2-promoting subclass of IgG1 was the predominant isotype in S. japonicum infected mice. More importantly, footpad injection of SjCyP18 induced a greater production of IL-4 than that of IFN-γ by lymphocytes compared to responses from PBS injection controls. Conclusion The cyclophilin A homologue found in S. japonicum is immunogenic and promotes Th2 responses in vivo which may contribute to the establishment of chronic infection by schistosomes.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Xiao-Ping Chen
- Department of Immunology, Tongji University School of Medicine, Shanghai 200092, China.
| |
Collapse
|
15
|
Protective immunity to Schistosoma haematobium infection is primarily an anti-fecundity response stimulated by the death of adult worms. Proc Natl Acad Sci U S A 2012; 109:13347-52. [PMID: 22847410 DOI: 10.1073/pnas.1121051109] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Protective immunity against human schistosome infection develops slowly, for reasons that are not yet fully understood. For many decades, researchers have attempted to infer properties of the immune response from epidemiological studies, with mathematical models frequently being used to bridge the gap between immunological theory and population-level data on schistosome infection and immune responses. Here, building upon earlier model findings, stochastic individual-based models were used to identify model structures consistent with observed field patterns of Schistosoma haematobium infection and antibody responses, including their distributions in cross-sectional surveys, and the observed treatment-induced antibody switch. We found that the observed patterns of infection and antibody were most consistent with models in which a long-lived protective antibody response is stimulated by the death of adult S. haematobium worms and reduces worm fecundity. These findings are discussed with regard to current understanding of human immune responses to schistosome infection.
Collapse
|
16
|
Xu X, Sun J, Zhang J, Wellems D, Qing X, McCutchan T, Pan W. Having a pair: the key to immune evasion for the diploid pathogen Schistosoma japonicum. Sci Rep 2012; 2:346. [PMID: 22468230 PMCID: PMC3315692 DOI: 10.1038/srep00346] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 03/02/2012] [Indexed: 01/02/2023] Open
Abstract
Schistosomes, unlike malaria parasites, are in their diploid stage when targeted by the human immune system. Diploids can be either homozygous or heterozygous. The difference has profound significance for developing immunity and yet has not previously been addressed. We examined the implications of zygosity on immunity to a diploid pathogen, Schistosoma japonicum and showed that the diploid state, and its associated heterozygous advantage, significantly affects the outcome of attack by the immune system and the accumulation of antigenic diversity in the parasite population. We demonstrate here that diploidy provides a novel means of immune evasion for diploid pathogens.
Collapse
Affiliation(s)
- Xindong Xu
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, PR China
| | | | | | | | | | | | | |
Collapse
|
17
|
Vaccine potential of hemocyanin from Oncomelania hupensis against Schistosoma Japonicum. Parasitol Int 2011; 60:242-6. [DOI: 10.1016/j.parint.2011.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 02/21/2011] [Accepted: 03/19/2011] [Indexed: 11/24/2022]
|
18
|
Zhang M, Han Y, Zhu Z, Li D, Hong Y, Wu X, Fu Z, Lin J. Cloning, expression, and characterization of Schistosoma japonicum tegument protein phosphodiesterase-5. Parasitol Res 2011; 110:775-86. [PMID: 21779860 DOI: 10.1007/s00436-011-2552-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 07/06/2011] [Indexed: 12/27/2022]
Abstract
The tegument proteins of schistosomes are regarded as potential vaccine candidates and drug targets to control schistosomiasis. Nucleotide pyrophosphatase/phosphodiesterase-5 (NPP-5), which belongs to a multigene family of nucleotide pyrophosphatase/phosphodiesterases (NPPs), is important in the hydrolysis of pyrophosphate or phosphodiester bonds in nucleotides and their derivatives. In the present study, SjNPP-5, identified as one of the tegument proteins of Schistosoma japonicum in our previous proteomic studies, was cloned on a fragment of 1,371 bp and expressed as a recombinant protein of 69 kDa. Real-time RT-PCR analysis showed that SjNPP-5 was up-regulated at 21-42 days, and the expression level in 42-day-old male worms was almost nine times higher than that in females. Western blot analysis revealed that rSjNPP-5 had good antigenicity. Immunofluorescence analysis found that SjNPP-5 was a membrane-associated antigen mainly distributed on the surface of the male adult worm of S. japonicum. BALB/c mice vaccinated with rSjNPP-5 three times showed a 29.90% worm reduction (P < 0.05) and a 26.21% egg count reduction (P > 0.05). Immunization with rSjNPP-5 induced a mixed Th1/Th2 response in which Th1 was dominant. The response was characterized by a reduced IgG1/IgG2a ratio and elevated production of cytokines IFN-γ and IL-4. This study suggested that SjNPP-5 may be important in schistosome development, and further investigations are required to fully understand the function of this molecule.
Collapse
Affiliation(s)
- Min Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology, Ministry of Agriculture, 518 Ziyue road, Minhang, Shanghai 200241, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Hamed MA, Ali SA, Aly HF, El-Rigal NS, Rizk MZ. Biomphalaria alexandrina snails as immunogens against Schistosoma mansoni infection in mice. Mem Inst Oswaldo Cruz 2010; 105:879-88. [PMID: 21120357 DOI: 10.1590/s0074-02762010000700007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Accepted: 08/12/2010] [Indexed: 11/22/2022] Open
|
20
|
Schistosomiasis in the People's Republic of China: the era of the Three Gorges Dam. Clin Microbiol Rev 2010; 23:442-66. [PMID: 20375361 DOI: 10.1128/cmr.00044-09] [Citation(s) in RCA: 166] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The potential impact of the Three Gorges Dam (TGD) on schistosomiasis transmission in China has invoked considerable global concern. The TGD will result in changes in the water level and silt deposition downstream, favoring the reproduction of Oncomelania snails. Combined with blockages of the Yangtze River's tributaries, these changes will increase the schistosomiasis transmission season within the marshlands along the middle and lower reaches of the Yangtze River. The changing schistosome transmission dynamics necessitate a comprehensive strategy to control schistosomiasis. This review discusses aspects of the epidemiology and transmission of Schistosoma japonicum in China and considers the pathology, clinical outcomes, diagnosis, treatment, immunobiology, and genetics of schistosomiasis japonica together with an overview of current progress in vaccine development, all of which will have an impact on future control efforts. The use of synchronous praziquantel (PZQ) chemotherapy for humans and domestic animals is only temporarily effective, as schistosome reinfection occurs rapidly. Drug delivery requires a substantial infrastructure to regularly cover all parts of an area of endemicity. This makes chemotherapy expensive and, as compliance is often low, a less than satisfactory control option. There is increasing disquiet about the possibility that PZQ-resistant schistosomes will develop. Consequently, as mathematical modeling predicts, vaccine strategies represent an essential component in the future control of schistosomiasis in China. With the inclusion of focal mollusciciding, improvements in sanitation, and health education into the control scenario, China's target of reducing the level of schistosome infection to less than 1% by 2015 may be achievable.
Collapse
|