Broad objectives of our research are to understand the cellular and molecular mechanisms which result in transmission of the human blood fluke Schistosoma mansoni in certain individual host snails (Biomphalaria glabrata), and the failure of transmission in others. This requires knowledge of the events which culminate in compatibility and those that result in incompatibility. Specifically we seek to identify parasite-borne characters which modulate infectivity and host-borne characters which determine susceptibility or resistance. In order to describe molecular events involved in parasite recognition by the intermediate host snail, the complex sporocyst- hemocyte system which occurs in vitro will be simplified for experimental analysis. Sporocyst surface components will be placed on activated beads. Hemocyte recognition of these sporocyst- labelled beads will be assessed by association of the two in vitro. Association indices will be obtained for hemocytes from snails which are susceptible to the schistosome and those from snails which are resistant. Hemocytes from naive and from parasite- exposed snails will be compared. The influence of snail plasma will be evaluated in experiments where the sporocyst-labelled beads are exposed to plasma before they are offered to hemocytes. Plasma will be derived from both susceptible and resistant snail strains, and from naive parasite-exposed individuals. Recognition factors on hemocyte surfaces and those from the plasma will be studied for their influence on the outcome of hemocyte- sporocyst encounters using a well tried cytotoxicity assay system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Unknown (R22)
Project #
2R22AI016137-07
Application #
3565452
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1981-09-30
Project End
1991-11-30
Budget Start
1988-12-01
Budget End
1989-11-30
Support Year
7
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Oregon State University
Department
Type
DUNS #
053599908
City
Corvallis
State
OR
Country
United States
Zip Code
97339
Tavalire, Hannah F; Blouin, Michael S; Steinauer, Michelle L (2016) Genotypic variation in host response to infection affects parasite reproductive rate. Int J Parasitol 46:123-31
Tennessen, Jacob A; Bonner, Kaitlin M; Bollmann, Stephanie R et al. (2015) Genome-Wide Scan and Test of Candidate Genes in the Snail Biomphalaria glabrata Reveal New Locus Influencing Resistance to Schistosoma mansoni. PLoS Negl Trop Dis 9:e0004077
Tennessen, Jacob A; Théron, André; Marine, Melanie et al. (2015) Hyperdiverse gene cluster in snail host conveys resistance to human schistosome parasites. PLoS Genet 11:e1005067
Larson, Maureen K; Bender, Randal C; Bayne, Christopher J (2014) Resistance of Biomphalaria glabrata 13-16-R1 snails to Schistosoma mansoni PR1 is a function of haemocyte abundance and constitutive levels of specific transcripts in haemocytes. Int J Parasitol 44:343-53
Hoffmann, Christopher J; Ledwaba, Johanna; Li, Jin-Fen et al. (2013) Resistance to tenofovir-based regimens during treatment failure of subtype C HIV-1 in South Africa. Antivir Ther 18:915-20
Duwell, Monique M; Knowlton, Amy R; Nachega, Jean B et al. (2013) Patient-nominated, community-based HIV treatment supporters: patient perspectives, feasibility, challenges, and factors for success in HIV-infected South African adults. AIDS Patient Care STDS 27:96-102
Svensson, Elin; van der Walt, Jan-Stefan; Barnes, Karen I et al. (2012) Integration of data from multiple sources for simultaneous modelling analysis: experience from nevirapine population pharmacokinetics. Br J Clin Pharmacol 74:465-76
Bonner, Kaitlin M; Bayne, Christopher J; Larson, Maureen K et al. (2012) Effects of Cu/Zn superoxide dismutase (sod1) genotype and genetic background on growth, reproduction and defense in Biomphalaria glabrata. PLoS Negl Trop Dis 6:e1701
Steinauer, Michelle L; Bonner, Kaitlin M (2012) Host susceptibility is altered by light intensity after exposure to parasites. J Parasitol 98:1052-4
Hoffmann, Christopher J; Fielding, Katherine L; Johnston, Victoria et al. (2011) Changing predictors of mortality over time from cART start: implications for care. J Acquir Immune Defic Syndr 58:269-76

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