Trichomonas vaginalis, causes one of the most common sexually transmitted disease in humans, trichomoniasis. Trichomoniasis is a serious disease that causes flagrant vaginitis and has been linked to infertility, preterm delivery, low birth weight infants, cervical cancer and markedly increased susceptibility to HIV. Cell surface glycoconjugates appear to mediate parasite binding to host cells. An in vitro culture system of human vaginal epithelial cells (HVECs), which exhibits parasite-host specificity, has been developed. Exposure of HVECs to parasites results in destruction of HVECs within 30 h. Periodate treated parasites do not damage HVECs. T. vaginalis possesses a cell surface glycoconjugate, lipophosphoglycan (LPG), which displaces parasites binding to HVECs, implying a specific receptor-ligand interaction. A related water soluble glycan (TV-SG), released by parasites, has also been purified. The long term goal of this proposal is to elucidate the mechanism(s) of T. vaginalis pathobiology on a molecular and cellular level.
The specific aims are: 1) to utilize the HVEC culture system and an 35S-methionine-labeled-parasite binding-displacement assay to study the role of LPG in host-parasite adhesion, and to identify and purify """"""""receptor"""""""" molecules on the HVEC surface that bind parasites. 2) to complete the structural characterization of LPG and study its relationship to TV-SG; with the expectation that structural analysis will be correlated with bioactivity. The binding assay will also be employed to assay portions of the LPG molecule derived by chemical and enzymatic treatments. 3) Parasite cytotoxicity toward HVECs will be studied by quantitative assays and contact-dependent and contact-independent mechanisms will be evaluated. HVEC destruction will be assayed for necrosis vs. apoptosis using an ELISA assay. Receptor purification will be based on either a panning technique to search for radiolabeled HVEC surface molecules that bind to LPG or an affinity column approach with immobilized LPG. LPG structure will be characterized using a variety of techniques, including HPLC, Glyko-FACE, MALDI-TOF MS and NMR. These studies will help to define the mechanisms of T. vaginalis pathogenicity, which will ultimately lead to better treatments for trichomoniasis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI047334-02
Application #
6362451
Study Section
Pathobiochemistry Study Section (PBC)
Program Officer
Quackenbush, Robert L
Project Start
2000-03-15
Project End
2003-02-28
Budget Start
2001-03-01
Budget End
2002-02-28
Support Year
2
Fiscal Year
2001
Total Cost
$264,775
Indirect Cost
Name
Upstate Medical University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
058889106
City
Syracuse
State
NY
Country
United States
Zip Code
13210
Kummer, Shelley; Hayes, Gary R; Gilbert, Robert O et al. (2008) Induction of human host cell apoptosis by Trichomonas vaginalis cysteine proteases is modulated by parasite exposure to iron. Microb Pathog 44:197-203
Fichorova, Raina N; Trifonova, Radiana T; Gilbert, Robert O et al. (2006) Trichomonas vaginalis lipophosphoglycan triggers a selective upregulation of cytokines by human female reproductive tract epithelial cells. Infect Immun 74:5773-9
Sommer, Ulf; Costello, Catherine E; Hayes, Gary R et al. (2005) Identification of Trichomonas vaginalis cysteine proteases that induce apoptosis in human vaginal epithelial cells. J Biol Chem 280:23853-60
Singh, Bibhuti N; Hayes, Gary R; Lucas, John J et al. (2005) In vitro cytopathic effects of a cysteine protease of Tritrichomonas foetus on cultured bovine uterine epithelial cells. Am J Vet Res 66:1181-6
Singh, B N; Lucas, J J; Hayes, G R et al. (2004) Tritrichomonas foetus induces apoptotic cell death in bovine vaginal epithelial cells. Infect Immun 72:4151-8