ps Abstract): Encystation in the human parasite Entamoeba histolytica cannot be studied in vitro. The related reptilian parasite, E. invadens, will encyst in vitro and can be used as model system to study encystation in Entamoeba. Two sugars inhibit the amebic encystation process. Galactose prevents the aggregation of ameba, which precedes encystation while N acetyl glucosamine allows aggregation to occur but still prevents the formation of osmotically resistant cysts. This proposal will study the role of galactose ligands and their receptor in the encystment process. An ortholog of the light subunit of the GalNAc lectin of E. histolytica has been cloned from E. invadens. The E. invadens gene product binds galactose and mucin, appears to be found on the surface of the ameba and likely mediates the initial cellular aggregation step. Gal-terminated glycoconjugates stimulate encystation in a concentration-dependent manner and suggest a role for the lectin in parasite differentiation. The structure of the lectin and a proposed mechanism of regulating encystation will be examined in this proposal.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI044893-01A2
Application #
6127297
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Program Officer
Fairfield, Alexandra
Project Start
2000-03-01
Project End
2004-02-29
Budget Start
2000-03-01
Budget End
2001-02-28
Support Year
1
Fiscal Year
2000
Total Cost
$371,250
Indirect Cost
Name
New York University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
City
New York
State
NY
Country
United States
Zip Code
10016
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