: Hookworm infection is a leading cause of malnutrition and anemia in the developing world. More than one billion people are infected with these bloodfeeding nematode parasites, which attach to the intestinal mucosa and feed from lacerated capillaries. Hookworms may survive for years within the intestine, despite the presence of a host inflammatory response. To date, little is known about the mechanisms by which adult hookworms block components of the innate and acquired host immune responses in order to survive. A eDNA corresponding to a homologue of the mammalian cytokine Macrophage Migration Inhibitory Factor (MIF) has recently been cloned from the human hookworm Ancylostoma ceylanicum. Preliminary data suggest that the recombinant A. ceylanicum MIF (rAceMIF) is enzymatically active and competes with the human protein for binding to the recently identified MIF receptor CD74. We hypothesize that the hookworm MIF homologue effectively modulates the host immune response in order to facilitate parasite survival at the mucosal surface.
The aim of this project is to characterize the role of MIF in the pathogenesis of hookworm infection and disease. The mechanism of action of AceMIF will be characterized using in vitro studies of MIF function, including tautomerase activity, macrophage migration, and pro-inflammatory cell signaling. The kinetics of rAceMIF binding to CD74 will be characterized, and its three dimensional structure will be elucidated using X-ray crystallography. AceMIF gene expression will be characterized in vivo in order to document its stage specificity, and the source of AceMIF production within the adult hookworm will be characterized by immunohistochemistry. Parallel studies will analyze tissue specific expression of host MIF in response to hookworm infection using a fully permissive animal model of A. ceylanicum. The role of AceMIF in the pathogenesis of hookworm anemia and growth delay will also be characterized using both vaccine and targeted gene silencing approaches. The response to immunization will be monitored by ELISA, and the degree to which antibodies directed at AceMIF protect against hookworm anemia and growth delay will be assessed using clinical parameters and worm burden measurements. These studies will characterize this novel helminth homologue of a multi functional human cytokine, ultimately determining the role of MIF in the pathogenesis of hookworm disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI058980-03
Application #
7156995
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Program Officer
Wali, Tonu M
Project Start
2005-01-15
Project End
2009-12-31
Budget Start
2007-01-01
Budget End
2007-12-31
Support Year
3
Fiscal Year
2007
Total Cost
$387,569
Indirect Cost
Name
Yale University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
06520
Fairfax, Keke C; Harrison, Lisa M; Cappello, Michael (2014) Molecular cloning and characterization of a nematode polyprotein antigen/allergen from the human and animal hookworm Ancylostoma ceylanicum. Mol Biochem Parasitol 198:37-44
Cho, Yoonsang; Vermeire, Jon J; Merkel, Jane S et al. (2011) Drug repositioning and pharmacophore identification in the discovery of hookworm MIF inhibitors. Chem Biol 18:1089-101
Kucera, Kaury; Harrison, Lisa M; Cappello, Michael et al. (2011) Ancylostoma ceylanicum excretory-secretory protein 2 adopts a netrin-like fold and defines a novel family of nematode proteins. J Mol Biol 408:9-17
Dondji, B; Sun, T; Bungiro, R D et al. (2010) CD4 T cells mediate mucosal and systemic immune responses to experimental hookworm infection. Parasite Immunol 32:406-13
Espitia, Claudia M; Zhao, Weiguo; Saldarriaga, Omar et al. (2010) Duplex real-time reverse transcriptase PCR to determine cytokine mRNA expression in a hamster model of New World cutaneous leishmaniasis. BMC Immunol 11:31
Fairfax, Keke C; Vermeire, Jon J; Harrison, Lisa M et al. (2009) Characterisation of a fatty acid and retinol binding protein orthologue from the hookworm Ancylostoma ceylanicum. Int J Parasitol 39:1561-71
Vermeire, Jon J; Cho, Yoonsang; Lolis, Elias et al. (2008) Orthologs of macrophage migration inhibitory factor from parasitic nematodes. Trends Parasitol 24:355-63
Dondji, Blaise; Bungiro, Richard D; Harrison, Lisa M et al. (2008) Role for nitric oxide in hookworm-associated immune suppression. Infect Immun 76:2560-7
Reiss, Daniel; Harrison, Lisa M; Bungiro, Richard et al. (2007) Short report: an agar plate method for culturing hookworm larvae: analysis of growth kinetics and infectivity compared with standard coproculture techniques. Am J Trop Med Hyg 77:1087-90
Cho, Yoonsang; Jones, Brian F; Vermeire, Jon J et al. (2007) Structural and functional characterization of a secreted hookworm Macrophage Migration Inhibitory Factor (MIF) that interacts with the human MIF receptor CD74. J Biol Chem 282:23447-56