Hookworm-Derived Metabolites Suppress Pathology in a Mouse Model of Colitis and Inhibit Secretion of Key Inflammatory Cytokines in Primary Human Leukocytes

• Published in: Infection and immunity 2019-04, Vol.87 (4)
• Main Authors: Wangchuk, Phurpa, Shepherd, Catherine, Constantinoiu, Constantin, Ryan, Rachael Y M, Kouremenos, Konstantinos A, Becker, Luke, Jones, Linda, Buitrago, Geraldine, Giacomin, Paul, Wilson, David, Daly, Norelle, McConville, Malcolm J, Miles, John J, Loukas, Alex
• Format: Article
• Language: English
• Subjects: Ancylostoma - chemistry; Ancylostoma - metabolism; Animals; Anti-Inflammatory Agents - administration & dosage; Anti-Inflammatory Agents - chemistry; Anti-Inflammatory Agents - metabolism; Biological Therapy; Colitis - genetics; Colitis - immunology; Colitis - therapy; Cytokines - genetics; Cytokines - immunology; Disease Models, Animal; Fatty Acids - administration & dosage; Fatty Acids - chemistry; Fatty Acids - metabolism; Female; Fungal and Parasitic Infections; Humans; Leukocytes, Mononuclear - immunology; Male; Mice; Mice, Inbred BALB C
• ISSN: 0019-9567; 1098-5522
• DOI: 10.1128/IAI.00851-18

Iatrogenic hookworm therapy shows promise for treating disorders that result from a dysregulated immune system, including inflammatory bowel disease (IBD). Using a murine model of trinitrobenzenesulfonic acid-induced colitis and human peripheral blood mononuclear cells, we demonstrated that low-molecular-weight metabolites derived from both somatic extracts (LMWM-SE) and excretory-secretory products (LMWM-ESP) of the hookworm, , display anti-inflammatory properties. Administration to mice of LMWM-ESP as well as sequentially extracted fractions of LMWM-SE using both methanol (SE-MeOH) and hexane-dichloromethane-acetonitrile (SE-HDA) resulted in significant protection against T cell-mediated immunopathology, clinical signs of colitis, and impaired histological colon architecture. To assess bioactivity in human cells, we stimulated primary human leukocytes with lipopolysaccharide in the presence of hookworm extracts and showed that SE-HDA suppressed production of inflammatory cytokines. Gas chromatography-mass spectrometry (MS) and liquid chromatography-MS analyses revealed the presence of 46 polar metabolites, 22 fatty acids, and five short-chain fatty acids (SCFAs) in the LMWM-SE fraction and 29 polar metabolites, 13 fatty acids, and six SCFAs in the LMWM-ESP fraction. Several of these small metabolites, notably the SCFAs, have been previously reported to have anti-inflammatory properties in various disease settings, including IBD. This is the first report showing that hookworms secrete small molecules with both and anti-inflammatory bioactivity, and this warrants further exploration as a novel approach to the development of anti-inflammatory drugs inspired by coevolution of gut-dwelling hookworms with their vertebrate hosts.