Does the parasitic worm product ES-62 resolve aberrant chronic inflammation by sensing and normalising the gut microbiome and intestinal integrity?

People are now living much longer, mainly due to better disease control, greater access to food, and improved sanitation such that by 2050, 25% of the UK population will be over 65. However, our increasing lifespan is causing major socio-economic issues, because it is not accompanied by an equivalent extension of well-being ("healthspan"). Although this disconnect reflects natural "wear and tear" on our bodies, current life-styles, combining a high calorie diet (HCD) with sedentary behavior, are promoting alarming increases in age-associated ailments such as obesity, type-2 diabetes, stroke and heart disease. In addition, obesity is a reciprocal risk factor for development of autoimmunity, a group of diseases including, for example, rheumatoid arthritis (RA) that arise when the body's immune system, which normally protects against infectious agents, begins to attack its own tissues.

Increasing evidence suggests that development of both ageing-associated conditions and autoimmunity can be avoided by infection with parasitic worms or products that they secrete. Indeed, using mice in which the conditions can be modelled, we showed that an anti-inflammatory worm product called ES-62 was highly effective in suppressing development of a range of diseases including both atherosclerosis and RA. Furthermore, we have found that administering ES-62 weekly throughout the life of HCD-fed mice improves multiple aspects of their health and even makes male mice live longer. While attempting to discover ES-62's mechanism of action, a key observation to emerge from both our ageing and RA studies was that the worm product maintains gut health, which is disrupted by both HCD and arthritis. Specifically, ES-62 reduces damage to the gut barrier that protects against infection and prevents changes in the composition of bacteria (the microbiome) in the bowel, meaning that species that promote good health are maintained.

The normal maintenance of gut health and consequently, immune responses that target infectious agents rather than host tissues relies on a complex network of different cells of the immune system, located within the gut microenvironment to coordinate bidirectional interactions with the microbiome. Our previous studies indicate that ES-62 can directly modify the activities of some of these cell types when isolated from other organs in the mouse, e.g., B cells recovered from the spleen. We therefore now wish to determine whether effects on any of these cell types present within the intestinal microenvironment are responsible for maintaining gut health, thereby in turn preventing inflammation and promoting wellbeing. Thus, we plan to:

1. Comprehensively examine the effect of ES-62 on gut health, focusing on the different cells in the local environment. Based on supportive data from previous studies, we particularly anticipate a role for ES-62 targeting of interactions between two types, called CD1d+ regulatory B cells and invariant NKT cells, in countering inflammation and normalising the composition of the microbiome.
2. Identify how key target cells of ES-62 are modified to effect protection and examine whether their transfer into recipient mice functionally recapitulates the actions of ES-62.
3. Define whether in addition to ES-62 acting directly on target cells, it has any indirect effects, e.g., by promoting enrichment of bacteria species that produce molecules such as butyrate that are known to support a healthy gut.

To achieve our objectives, we plan to employ a combination of approaches, first exploiting tissue from biobanks that we generated during our recently completed obesity-accelerated ageing and arthritis experiments and then undertaking new studies making use of our mouse models of HCD-induced ageing and RA.

During parasitism, helminths secrete molecules to modulate host inflammatory responses. Consistent with the potential for employing such molecules therapeutically, we have reported that ES-62, a phosphorylcholine (PC)-containing glycoprotein secreted by Acanthocheilonema viteae, protects mice against both collagen-induced arthritis (CIA) and ill health associated with life-long consumption of a high calorie diet (HCD). In both models of inflammation-driven morbidity, ES-62-protection correlates with its ability to normalise disease-induced changes in the microbiome, maintain gut homeostasis and via restoration of IL-10+ regulatory B cells, reset immunoregulatory networks. Our aim is thus to establish how ES-62 resolves chronic inflammatory responses by sensing and normalising the gut microbiome and promoting gut barrier integrity.

The gut has evolved a complex cellular network, comprising epithelial cells, B cells, dendritic cells, gammadelta T cells, innate lymphoid cells and NKT cells, that coordinates bidirectional signalling with the microbiota to train immune responses and maintain gut homeostasis. This becomes defective during infection, autoimmunity, obesity and ageing and we specifically plan to elucidate how ES-62 counters this. In particular, we will define which cell types ES-62 targets in promoting gut health, establish how they are reprogrammed, and validate their health-endorsing roles by investigating whether their transfer to recipient mice functionally recapitulates ES-62-actions. We will also assess whether in addition to directly rewiring these cells, ES-62 fosters gut health indirectly, via induction of immunomodulatory anti-PC antibodies or enrichment of microbiota metabolites such as butyrate that support barrier integrity. To achieve these objectives, we will exploit biobanked tissue from completed HCD-accelerated ageing and CIA studies in addition to undertaking further experiments employing these two models of chronic inflammation.

The research to be undertaken could have academic impact on:

1. Young researcher development: the post-doctoral research assistant (PDRA), Dr Felicity Lumb, will receive further multidisciplinary research training focusing on the impact of ES-62 on microbiome dysbiosis and failure of gut barrier integrity driving the chronic inflammation underpinning the debilitating conditions associated with ageing. This will additionally allow her to increase her skills in assessment of potential targets for therapeutic intervention for future ES-62-based drug development. At the same time, she will further expand her expertise in both project management of collaborative research and oral and written presentation, all of which will promote her development as an independent scientist, thereby facilitating future employability.

2. Knowledge exchange: in addition to providing added value to related ES-62 projects on countering inflammatory disease, microbiota-host interactions and the impact of dietary restriction on heath- and lifespan, our unique ageing biobank and data set resources will benefit collaborators and the wider research community working on the biology of ageing and microbiome-regulated inflammatory disease. Moreover, greater understanding of the mechanism of action of ES-62 will interest scientists considering the broad therapeutic potential of helminth-derived molecules that modulate the immune response as well as those working on immune system evasion and anthelmintic therapies. With respect to the latter, helminths infect around one quarter of the global population and also represent a huge economic burden on animal and plant farming.

Impacts could also relate to:
1. Fostering the economic competitiveness of the UK and global biopharma industry: The proposal seeks to increase our fundamental understanding of how ES-62 impacts on the gut sensory mechanisms bidirectionally regulating the microbiota and shaping of immune responses across the lifecourse. As ageing-associated dysfunction of these processes underlies susceptibility to infection and drives development of the autoimmune, metabolic and cardiovascular complications that are accelerated by the chronic inflammation resulting from obesity, our data could also identify potential novel sites of therapeutic intervention. Given the global major health challenges presented by our ageing and increasingly obese population, these could be exploited by Biopharma. Moreover, as we have already patent-protected small molecule analogues (SMAs) that mimic the immunomodulatory actions of ES-62, these new studies could help facilitate their development as novel drugs. Any licensing agreement/spin-out company arising out of the IP generated by the project would raise the global profile and economy of our universities.

2. Public Services and Policy: Identification of biomarkers, novel sites of intervention and the development of ES-62-based SMAs as drugs could ultimately impact on regulatory bodies such as the Medicines and Healthcare Products Regulatory Agency and the National Institute for Biological Standards and Control in the UK and also globally, for example, via the USA Federal Drug Agency in terms of drug licensing and patient treatment guidelines.

3. Patients: Autoimmunity, age- and life style-associated disorders are of dramatically increasing prevalence and currently, there are no entirely effective therapeutic strategies. Of note, as our already generated SMAs exhibit good ADMET/pharmacokinetic properties, their successful development could be short/mid- rather than long-term. This could have potential major socio-economic impacts for these ageing-associated inflammatory conditions, which pose a daunting scenario, not only of large-scale poor quality of life and disability but also of consequent reduced economic performance and dramatically increased health costs.