We study a range of parasitic species, according to the scientific question being addressed. Our primary interest revolves around long-lived helminth parasites, which includes human pathogens such as Brugia malayi, as well as zoonotic organisms (eg Echinococcus granulosus and Toxocara canis) and model system nematodes (eg Heligmosomoides polygyrus, Litomosoides sigmodontis and Nippostrongylus brasiliensis). In addition, transfection studies have been designed to use the protozoa Leishmania as a tool to express transgenes from parasitic helminths.
Features of each system in brief :
Human parasite, can be maintained in laboratory; extensive data on immune response in patients and model system hosts; detailed characterisation of antigens at molecular level; draft genome sequence reported by Ghedin et al (2007) Science 317: 1756-1760.
Cestode (tapeworm) parasites of canids which can cause serious disease in humans. Our work on this parasite focuses on molecular biology and gene discovery (see Fernandez et al 2002 Mol Biochem Parasitol 122:171-180) ; the Sanger Institute is sequencing this species and the related parasite E. multilocularis.
A model system gastrointestinal nematode, naturally infective to murine species, which can establish long-term chronic infection and down-modulates immune responsiveness in multiple settings including allergy, autoimmunity and colitis; the key immunological features of the infection have recently been reviewed by our laboratory (Maizels et al 2011, Experimental Parasitology in press).. The parasite can readily be maintained in the laboratory and is widely used in immunology and parasitology research.
A newly developed system in which the entire filarial life cycle can be completed in the laboratory model context (Hoffmann et al 2000 Parasitol Today 16:387-389). This species has allowed, for the first time, the components of protective immunity against tissue-dwelling filariae to be defined, and we have used it to demonstrate that interference with regulatory T cells in vivo curtails survival of the parasites.
The most commonly studied nematode parasite in the laboratory. It completes a rapid life cycle (~7-10 days) in rodents, and generates a powerful and protective Th2 response in vivo. Can be cultivated in vitro, and the secreted antigens have been found to themselves drive Th2 responses, in part through the activation of dendritic cells into a Th2-inducing phenotype (Holland et al 2000 Eur J Immunol 30: 1977-1987).
A zoonotic infection of humans, particularly of children and those at risk of ingesting infective eggs from contaminated soil. Infective to a remarkable range of mammalian hosts, and able to survive for years in a state of arrested development. In vitro cultivation is also possible, and the released antigens from tissue culture contain important immunomodulatory molecules (Maizels et al 2000 Int J Parasitol 30: 495-508).
Human parasite, can only be maintained outside humans in leaf monkeys, but where comparisons have been possible has been shown to be extremely similar to B. malayi (for example, Morgan et al 1986Parasitology 93: 559-569). Further information available on the NGO Amaury Coutinho website in Recife, Brazil. A small number of ESTs are reported on the nematode.net website.