Retroviral transduction of cultured schistosomes offers a potential means to establish transgenic lines of schistosomes and thereby to facilitate the elucidation of parasite gene function and expression. This is the long term objective of our studies. We propose to modify the Moloney murine leukemia retroviral (MMLV) vector pLNHX to incorporate luciferase and other reporter genes under control of endogenous schistosome gene promoters. pLNHX constructs and a plasmid encoding vesicular stomatitis virus glycoprotein (VSVG) will be used to transfect GP2-293 cells to produce replication incompetent retrovirus particles pseudo-typed with VSVG.
In Aim 1, the capacity of MMLV-VSVG retrovirus to transduce Schistosoma mansoni will be investigated. Developmental stages of schistosomes, including sporocysts, schistosomula and adults will be exposed to the retrovirus. Retroviral transduction of schistosomes will be facilitated by incubation with polybrene, phosphatidylserine and/or by centrifugation. The early stages of binding and uptake of virus to the tegument will be investigated by the immunofluorescence co-localization of VSVG and retroviral capsid proteins, and ultrastructural techniques. Downstream events, including integration of the pro-viral form of the retroviral transgene into schistosome chromosomes, transcription from integrated reporter genes, and activity of translated reporter proteins, will be investigated by Southern hybridization analysis, inverse PCR and related procedures, immunoblotting, and reporter proteins assays.
In Aim 2, we will transduce schistosomes with MMLV-VSVG virions modified with a transgene cassette encoding gene-specific, double stranded RNA (rather than a reporter gene such as luciferase, as in Aim 1). We will investigate whether this transduction is heritable and whether it leads to knockdown of gene transcription of a model target gene (i.e., cathepsin B, a gut-localized, hemoglobin-digesting enzyme);conventional RNAi targeting cathepsin B is known to deliver a visible phenotype - stunting of growth of schistosomula.
Aim 2 employs the retroviral transgenesis approach of Aim 1, i.e. gene """"""""knock-in"""""""", but is designed to establish heritable gene """"""""knock-out"""""""". Together, Aims 1 and 2 will investigate """"""""knock-in, knock-out"""""""" transgenesis for S. mansoni. In terms of public health, this investigation seeks to establish innovative methods to determine the importance of schistosome genes to aid the development of new therapies to treat and control schistosomiasis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI072773-04
Application #
7745520
Study Section
Pathogenic Eukaryotes Study Section (PTHE)
Program Officer
Mcgugan, Glen C
Project Start
2007-01-15
Project End
2011-12-31
Budget Start
2010-01-01
Budget End
2010-12-31
Support Year
4
Fiscal Year
2010
Total Cost
$540,978
Indirect Cost
Name
George Washington University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
043990498
City
Washington
State
DC
Country
United States
Zip Code
20052
Botelho, Monica C; Alves, Helena; Richter, Joachim (2016) Estrogen metabolites for the diagnosis of schistosomiasis associated urinary bladder cancer. SM Trop Med J 1:
Rinaldi, Gabriel; Loukas, Alex; Brindley, Paul J et al. (2015) Viability of developmental stages of Schistosoma mansoni quantified with xCELLigence worm real-time motility assay (xWORM). Int J Parasitol Drugs Drug Resist 5:141-8
Rinaldi, Gabriel; Yan, Hongbin; Nacif-Pimenta, Rafael et al. (2015) Cytometric analysis, genetic manipulation and antibiotic selection of the snail embryonic cell line Bge from Biomphalaria glabrata, the intermediate host of Schistosoma mansoni. Int J Parasitol 45:527-35
Botelho, Monica C; Figueiredo, Jacinta; Alves, Helena (2015) Bladder cancer and urinary Schistosomiasis in Angola. J Nephrol Res 1:22-24
Rinaldi, Gabriel; Young, Neil D; Honeycutt, Jared D et al. (2015) New research tools for urogenital schistosomiasis. J Infect Dis 211:861-9
Mann, Victoria H; Suttiprapa, Sutas; Skinner, Danielle E et al. (2014) Pseudotyped murine leukemia virus for schistosome transgenesis: approaches, methods and perspectives. Transgenic Res 23:539-56
Skinner, Danielle E; Rinaldi, Gabriel; Koziol, Uriel et al. (2014) How might flukes and tapeworms maintain genome integrity without a canonical piRNA pathway? Trends Parasitol 30:123-9
Botelho, Mónica C; Veiga, Isabel; Oliveira, Paula A et al. (2013) Carcinogenic ability of Schistosoma haematobium possibly through oncogenic mutation of KRAS gene. Adv Cancer Res Treat 2013:
Skinner, Danielle E; Rinaldi, Gabriel; Suttiprapa, Sutas et al. (2012) Vasa-Like DEAD-Box RNA Helicases of Schistosoma mansoni. PLoS Negl Trop Dis 6:e1686
Suttiprapa, Sutas; Rinaldi, Gabriel; Brindley, Paul J (2012) Genetic manipulation of schistosomes--progress with integration competent vectors. Parasitology 139:641-50

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