Exploring low molecular weight molecules produced by hookworms (Ancylostoma caninum) and their use as anti-inflammatory agents

Abstract

The dog hookworm, Ancylostoma caninum is an experimental model for human hookworm. Relying on the ancient association of hookworms and their host and guided by the observations of the Old friend's Theory these parasites may be a valuable source for therapeutic discovery. This thesis is designed to study the small molecules produced by the adult hookworm with particular emphasis on identifying molecules with anti-inflammatory potential using experimental techniques not applied to any helminth previously. To achieve this primary, aim the small molecular component of hookworm excretory/secretory fluid was extracted and separated. These fractions were separated using the small molecule techniques commonly employed in the study of ethnobotanicals. These extracts were tested in a mouse chemical colitis model known to exhibit Th1/Th17 responses, Th2 type hypertrophy, and innate immune response. This model is employed here as a broad-based bioactivity screen for immunomodulatory potential. Using these combined techniques, it was possible to identify several small molecule fractions exhibit a protective effect in TNBS mouse model of intestinal inflammation. These fractions have the potential to reveal therapeutic candidates for inflammatory disease. During this study it was also possible to characterise the small molecule secretome of A. caninum using gas chromatography/ mass spectroscopy. This characterisation has been able to describe over 300 features never described for A. caninum. The majority of the molecules have no currently described immunomodulatory activity. This includes low-molecular weight molecules hereto undescribed. In addition to this, a number of metabolites were identified, and these could be assigned to the described pathways of the human hookworm Necator americanus. It was possible to demonstrate that the small molecule milieu produced by adult dog hookworm is complex. Dog hookworm excretory/secretory material contains small molecule components that when administered to mice can prevent chemical colitis. These molecules present a novel pool of small molecules that have the potential to be used to treat inflammatory disease.