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Background and Aims To demonstrate that administration of 7500 Trichuris suis ova [TSO] every second week over 24 weeks would reduce the intestinal inflammation in moderate ulcerative colitis. Methods A single-centre, randomised, double-blinded, placebo-controlled, phase 2b clinical trial of 7500 Trichuris suis ova every 2 weeks for 24 weeks compared with placebo in moderate activity of ulcerative colitis [Mayo score 6–10] were performed. Primary outcome: clinical remission; secondary outcomes: clinical response at 24 weeks, complete corticosteroid-free clinical remission, endoscopic remission, symptomatic remission at 12 and 24 weeks, and partial Mayo score over time. Results In all, 119 patients were randomised to Trichuris suis ova [n = 60] or placebo [n = 59]. At Week 24, clinical remission was achieved in 30% of Trichuris suis ova-treated vs 34% of placebo-treated (risk ratio [RR] = 0.89; 95% confidence interval [CI]: 0.52–1.50; p = 0.80, intention to treat). No difference was found in clinical response in any of the clinical response subgroups. However, in patients who did not need treatment with corticosteroids during the trial, a temporary effect of TSO was seen in the analysis of symptomatic remission at Week 12 [p = 0.01] and the partial Mayo score at Week 14 and Week 18 [p < 0.05 and p = 0.02]. Conclusions Compared with placebo, Trichuris suis ova administration was not superior in achieving clinical remission at Week 24 in ulcerative colitis or in achieving clinical Mayo score reduction, complete corticosteroid-free clinical remission, or endoscopic remission. However, Trichuris suis ova treatment induced symptomatic temporary remission at Week 12.

Clinical trials have shown that administration of the nematode Trichuris suis can be beneficial in treating various immune disorders. To provide insight into the mechanisms by which this worm suppresses inflammatory responses, an active component was purified from T. suis soluble products (TsSPs) that suppress---- TNF and IL-12 secretion from LPS-activated human dendritic cells (DCs). Analysis by liquid chromatography tandem mass spectrometry identified this compound as prostaglandin (PG)E2. The purified compound showed similar properties compared with TsSPs and commercial PGE2 in modulating LPS-induced expression of many cytokines and chemokines and in modulating Rab7B and P2RX7 expression in human DCs. Furthermore, the TsSP-induced reduction of TNF secretion from DCs is reversed by receptor antagonists for EP2 and EP4, indicating PGE2 action. T. suis secretes extremely high amounts of PGE2 (45-90 ng/mg protein) within their excretory/secretory products but few related lipid mediators as established by metabololipidomic analysis. Culture of T. suis with several cyclooxygenase (COX) inhibitors that inhibit mammalian prostaglandin synthesis affected the worm's motility but did not inhibit PGE2 secretion, suggesting that the worms can synthesize PGE2 via a COX-independent pathway. We conclude that T. suis secretes PGE2 to suppress proinflammatory responses in human DCs, thereby modulating the host's immune response.-Laan, L. C., Williams, A. R., Stavenhagen, K., Giera, M., Kooij, G., Vlasakov, I., Kalay, H., Kringel, H., Nejsum, P., Thamsborg, S. M., Wuhrer, M., Dijkstra, C. D., Cummings, R. D., van Die, I. The whipworm (Trichuris suis) secretes prostaglandin E2 to suppress proinflammatory properties in human dendritic cells.

Oesophagostomum infections in pigs persist for months. We hypothesized that feeding fructans (dried chicory roots) may improve immunity and facilitate worm expulsion. We therefore examined the effects of long-term chicory on O. dentatum population dynamics and host immune responses. Methods: Seventy-two pigs were allocated to four groups in a 2-factorial design. Group O was fed regular feed and trickle inoculated with 15 O. dentatum L3/kg/day 0-12 weeks post-infection (pi.) start. Group OC was also trickle inoculated but switched to a chicory-rich diet (12% inulin in DM) weeks 3-12 pi. Group C was uninfected but switched to chicory diet while Group Ctr remained uninfected on regular feed. Six pigs per group were necropsied 5, 9 and 12 weeks pi. for worm counts and qRT-PCR for gene expression in the gut. Faecal egg counts (FEC) and specific antibody levels were assessed regularly. Results: When group OC switched to chicory diet, FECs dropped within 3-4 days and remained very low. Worm counts were reduced 50-65% by chicory feeding (Group OC versus O; p<0.001) and was accompanied by a 2-fold higher O. dentatum-specific IgG1 response. In group O, a build-up of a typical Th2-type immune response was seen but leveled out later and worm counts remained stable. Group C had a down-regulated Th1-type response and thus an anti-inflammatory effect in colon. Conclusions: We found little evidence that chicory feeding improved host protective immunity against Oesophagostomum. It seems more likely, as previously suggested, that physico-chemical changes in caeco-colon are responsible for the observed anthelmintic effects.

It has been shown that carbohydrates that are resistant to digestion in the small intestine but fermentable in the caecum and colon (prebiotics) may be adverse to Oesophagostomum detatum establishment in pigs and have a severe negative effect on egg production. However, there is some evidence that O.dentatum may adapt to the presence of chicory in the feed over time, and is Thus very relevant to examine the long-term effect on the parasite.

BACKGROUND: Eggs of the porcine whipworm Trichuris suis are currently explored in human clinical trials as a treatment of immune-mediated diseases. In this context, only the infective, embryonated eggs, constitute the Active Pharmaceutical Ingredient (API). The rodent whipworm, Trichuris muris is commonly used as a laboratory model to study Trichuris biology. The embryonated eggs (containing a fully developed larva) are biologically active and will invade the large intestinal mucosa of the host. This study aims to assess the in vitro hatching of T. muris and T. suis eggs in various bacterial cultures as a measure for their biological activity.METHODS: Eggs of T. muris and T. suis were incubated with Escherichia coli strain (BL-21) at three concentrations in a slightly modified in vitro egg hatching assay previously developed for T. muris. Additionally, E. coli strains (M15, SG13009, PMC103, JM109, TUNER, DH5alpha, TOP10) and five Gram-positive bacteria (Enterococcus caccae, Streptococcus hyointestinalis, Lactobacillus amylovorus, L. murinus, and L. reuteri) were tested as a hatching stimulus for T. muris and T. suis eggs.RESULTS: Whereas T. muris eggs hatched, T. suis did not, even when exposed to different concentrations and strains of E. coli after 4 and 24-hour incubation. When incubated with Gram-positive bacteria, only T. muris eggs showed noticeable hatching after 20 h, although with high variability.CONCLUSIONS: The observed difference in hatching of T. muris and T. suis eggs incubated with selected bacteria, indicate significant biological differences which may reflect specific adaptation to different host-specific gut microbiota.

A humoral immune response following helminth infection in pigs is well documented. However, it has been difficult to confirm the existence of antibody mediated resistance against the large roundworm, Ascaris suum, and whipworm, Trichuris suis, in experimental settings by correlating worm burdens or egg excretion with specific antibody levels. We set out to investigate the association between worm load and T. suis and A. suum specific serum antibody levels (IgG1, IgG2 and IgA) against excretory-secretory products of adults and third stage larvae, respectively, measured at 0, 7 and 14 weeks p.i. in a trickle-infected F1-resource-population of crossbred pigs (n=195). Furthermore, we wanted to determine the heritability of these antibody isotypes during the course of infection. Most pigs remained infected with A. suum throughout the experiment while they expelled T. suis between 7 and 14 weeks post infection (p.i.). Parasite specific IgG1 and IgA were significantly (P<0.001) elevated after 7 and 14 weeks of infection, whereas parasite specific IgG2 levels only changed slightly at 14 weeks p.i.. However, the observed association between specific antibody isotype levels and faecal egg counts and macroscopic worm load was weak. The relative heritabilities of the different parasite specific isotypes were assessed and resulted in significant heritability estimates for parasite specific IgG1 and IgA. The highest heritabilities were found for A. suum specific IgG1 (h(2)=0.41 and 0.46 at 7 and 14 weeks p.i., respectively). Thus, the present study demonstrates that host genetic factors influence the IgG1 and IgA antibody isotype responses specific to two of the most common gastrointestinal nematodes of swine whereas specific antibody levels were poorly associated with egg excretion and the presence of macroscopic worms.

The administration of helminths is considered a promising strategy for the treatment of autoimmune diseases due to their immunomodulatory properties. Currently, the application of the helminth Trichuris suis as a treatment for Crohn's disease is being studied in large multi-center clinical trials. The intestinal epithelium forms an efficient barrier between the intestinal lumen containing the microbial flora and helminths, and dendritic cells (DCs) present in the lamina propria that determine the TH response. Here, we investigated how excreted/secreted (E/S) products of T. suis affect the barrier function of intestinal epithelial cells (IECs) in order to reach the DCs and modulate the immune response. We show that T. suis E/S products reduce the barrier function and the expression of the tight junction proteins EMP-1 and claudin-4 in IEC CMT93/69 monolayers in a glycan-dependent manner. This resulted in an increased passage of soluble compounds to the basolateral side that affected DC function. In addition, T. suis E/S suppressed LPS-induced pro-inflammatory cytokine production by CMT93/69 cells, whereas the production of the TH2 response-inducing cytokine thymic stromal lymphopoietin (TSLP) was induced. Our studies indicate that T. suis E/S glycans affect the function of the intestinal epithelium in order to modulate DC function. Identification of the T. suis E/S glycans that modulate IEC and DC function may lead to a strategy to reduce symptoms of autoimmune and allergic immune diseases by orally administrated helminth-derived factors without the need of infection with live helminths.

Parasitism has been noted as the most successful way of life and organisms that are not parasites are usually hosts. Some of the most debilitating diseases in humans and animals are caused by parasitic nematodes. Among these are Trichuris spp., also referred to as whipworms, that causes infections in a wide range of host species. The disease is associated with heavy infections can lead to severe pathology and has occasionally deadly outcomes. An important source to the parasites’ success is their ability to evade host immune responses. However, knowledge of the exact molecules and mechanisms involved in these events is scarce. The human whipworm, Trichuris trichiura, infects over 400 million people worldwide and are often associated with lifelong chronic infections. Infections with the porcine whipworm, Trichuris suis, in pigs can, in high-prevalence areas, be a serious threat to animal welfare an may result in great economic losses for farmers due to reduced growth rates of the pigs. Although T. suis infections in pigs can have devastating consequences, T. suis infections in humans may be beneficial, as this parasite has been shown to have ameliorating effects on a range of autoimmune diseases, that are otherwise extraordinary difficult to treat. Although, not entirely clear, immunological processes, induced by the parasites in the host, have been suggested to play a role in the therapeutic effects. microRNAs are molecules that have been found to be involved in post-transcriptional regulation of genes associated with a wide range of biological processes and a distinctive miRNA profile has been obtained for various diseases. miRNAs show a remarkable stability as they often gain protection from ribonucleases in the blood by being transported inside vesicular structures, such as exosomes and microvesicles, that have been shown to be secreted by many different cell types and by some parasites. The aim of the present thesis was to detect miRNAs associ