Hookworm-derived small molecule extracts suppress pathology in a mouse model of colitis and inhibit secretion of key inflammatory cytokines in primary human leukocytes

Abstract

Iatrogenic hookworm therapy shows promise for treating disorders that result from 27 a dysregulated immune system, including inflammatory bowel disease (IBD). Here we use a 28 metabolomics approach to characterize the non-protein small molecule complement of 29 hookworms. Gas chromatography-mass spectrometry and liquid chromatography-mass 30 spectrometry analyses of somatic tissue extracts revealed the presence of 52 polar metabolites 31 and 22 non-polar components including short chain fatty acids (SCFA). Several of these small 32 metabolites, notably the SCFA, have been shown to have anti-inflammatory properties in various 33 diseases, including IBD. Using a murine model of colitis and human peripheral blood 34 mononuclear cells, we demonstrate that somatic tissue extracts of the hookworm Ancylostoma 35 caninum contain small molecules with anti-inflammatory activities. Of the five extracts tested, 36 two of them significantly protected mice against T cell-mediated immunopathology and weight 37 loss in a chemically-induced colitis model. Moreover, one of the anti-colitic extracts suppressed 38 ex vivo production of inflammatory cytokines from primary human leukocytes. While the origin 39 of the SCFA (parasite or host microbiota-derived) present in the hookworm somatic tissue 40 extracts cannot be ascertained from this study, it is possible that A. caninum may be actively 41 promoting an anti-inflammatory host microbiome by facilitating immune crosstalk through SCFA 42 production. 43 44 Short chain fatty acids; GC-MS; Metabolome 46 47 48 49 50 3 51 52Inflammatory Bowel Disease (IBD) is associated with chronic inflammation of the 53 digestive tract, and primarily includes ulcerative colitis (UC) and Crohn's disease (CD). The 54 etiology of IBD is not well established but it is usually characterized by inflammation, loss of 55 appetite and weight, chronic diarrhea, bloody stools, fever, rectal bleeding, abdominal pain, 56 fatigue, and anemia (1-3). IBD has been linked to many extra-intestinal manifestations (4) and 57 implicated with mental health problems (5). Current treatments for IBD include, 5-58 aminosalicylates, glucocorticosteroids, immunomodulators and biologics, and proctocolectomy 59 as a last resort when drug treatment fails. Many of these drugs are often associated with side-60 effects and various postoperative complications (6, 7). Frontline biologics such as treatment with 61 anti-TNF monoclonal antibodies are only efficacious in some patients and treatment does not 62 result in long term cure (8). Failure of these frontline treatments is associated with elevated risk 63 of colon cancer, and can result in the need for surgical removal of the colon (partial or full). 64There is therefore an urgent need for new and effective anti-inflammatory drugs to treat IBD. 65Guided by millennia of host-parasite co-evolution, we (9-13) and others (14-16) have 66 demonstrated the therapeutic properties of experimental hookworm infection to treat 67 gastrointestinal (GI) inflammatory diseases. Hookworms resident in ...

A netrin domain-containing protein secreted by the human hookworm Necator americanus protects against CD4 T cell transfer colitis

“…The identification of binding partners and the characterisation of the pharmacokinetics involved in Na-AIP-1 metabolism are fundamental in the determination of its potential for development as a novel biologic. Future work should further explore the impact of Na-AIP-1 on human tissues ex vivo, including APCs from gut biopsies of IBD patients.Whilst several studies have been published detailing the potential of hookwormderived products in the TNBS and DSS models of murine colitis,26,50,51 this is the first report of the prophylactic efficacy of a helminth-secreted protein in the robust murine T cell transfer model of colitis, which closely resembles human disease.Further, the discovery of a potential anti-inflammatory therapeutic from an anthropophilic parasite like the human hookworm N. americanus, as well as ex vivo bioactivity with a human macrophage cell line, may favour a greater safety profile if eventually translated to humans as a maintenance or preventative therapy. As such the studies contained within represent an exciting progression in development of helminth ES products as human biologics.…”

Natural strongyle infection reduces relative abundance of inflammation-inducingPrevotellain wild primates

“…Helminths may alter microbiota through competition for nutrients [15,37], or through excretory/secretory products (ESP) that alter the intestinal microbial habitat and/or protect the gut from inflammation [37]. Various helminths have been long known to secrete and/or excrete short chain fatty acids (SCFA) [38,39] and small molecules [39][40][41]. Many of these small molecules appear to have anti-inflammatory and other pharmacological properties [39][40][41].…”

“…Various helminths have been long known to secrete and/or excrete short chain fatty acids (SCFA) [38,39] and small molecules [39][40][41]. Many of these small molecules appear to have anti-inflammatory and other pharmacological properties [39][40][41]. SCFA have long been known to increase colonocyte proliferation, aid colonocyte function, promote adaptive gut responses to intestinal disturbances and injury, increase gut blood flow and motility, and decrease GI auto-immune pathology by inducing antiinflammatory cytokine secretion and enhancing local regulatory T cell numbers and function [42][43][44].…”

Peptides derived from hookworm anti-inflammatory proteins suppress inducible colitis in mice and inflammatory cytokine production by human cells

“…The excretory/secretory (ES) products of hookworms are a diverse source of molecules with potential in the treatment of inflammatory diseases such as IBD and asthma (5,(11)(12)(13). The ES products comprise a complex mixture of extracellular vesicles, proteins, carbohydrates, small molecules, metabolites and lipids secreted by the parasite (14).…”