The major pseudocoelomic proteins of the giant kidney worm and what they can tell us about other Clade 1 nematodes

MALCOLM W. KENNEDY; DOMINIK R. LAETSCH; NILDA E. RADMAN; LUCAS L. MALDONADO; MARK BLAXTER; BETINA CÓRSICO; A. NAHILI GIORELLO; LAURA KAMENETZKY; MARCOS J. BUTTI; FRANCHINI, GISELA RAQUEL

Hydra

Congreso; Molecular and Cellular Biology of Helminths XIII; 2019

The giant kidney worm, Dioctophyme renale, is a Clade I nematode that includes pathogens such as Trichuris, Trichinella, and Capillaria. The latter parasites are small and studying their proteins without resorting to recombinant methods can be difficult. D. renale is a very large nematode that infects and destroys typically the host?s right kidney, and is usually found in ectopic sites. It is circumglobally distributed, mainly in dogs, and is increasingly regarded as a threat to wildlife, domestic animals, and humans. We are investigating the soluble proteins of body wall, intestine, gonads and pseudocelomic fluid (PCF) of adult D. renale, which have already been found to be different from a similarly-sized Clade III worm, Ascaris. Two D. renale proteins stand out. P44 is closely related to the cysteine- and histidine-rich protein of Trichinella, and the ?immunologically silent? and potentially immunomodulatory p43 of Trichuris, the biological activity of neither of which is known. We present new information on the ligand-binding activity of P44. P17 accounts for the intense red colour of the parasites and we show that P17 is a haem-containing member of the nemoglobins that are widespread in other nematode Clades. Hence, while nemoglobins appear to have evolved before the split in nematode clades, P44-types may be a specialism for Clade I in substituting bulk lipid transport inside the parasites and potentially interacting with host tissues.