Microbiome- and Host Inflammasome-Targeting Inhibitor Nanoligomers Are Therapeutic in the Murine Colitis Model

Abstract

Autoimmune and autoinflammatory diseases account for more than 80 chronic conditions affecting more than 24 million people in the US. Among these autoinflammatory diseases, noninfectious chronic inflammation of the gastrointestinal (GI) tract causes inflammatory bowel diseases (IBDs), primarily Crohn’s and ulcerative colitis (UC). IBD is a complex disease, and one hypothesis is that these are either caused or worsened by compounds produced by bacteria in the gut. While traditional approaches have focused on pan immunosuppressive techniques (e.g., steroids), low remission rates, prolonged illnesses, and an increased frequency of surgical procedures have prompted the search for more targeted and precision therapeutic approaches. IBD is a complex disease resulting from both genetic and environmental factors, but several recent studies have highlighted the potential pivotal contribution of gut microbiota dysbiosis. Gut microbiota are known to modulate the immune status of the gut by producing metabolites that are encoded in biosynthetic gene clusters (BGCs) of the bacterial genome. Here, we show a targeted and high-throughput screening of more than 90 biosynthetic genes in 41 gut anaerobes, through downselection using available bioinformatics tools, targeted gene manipulation in these genetically intractable organisms using the Nanoligomer platform, and identification and synthesis of top microbiome targets as a Nanoligomer BGC cocktail (SB_BGC_CK1, abbreviated as CK1) as a feasible precision therapeutic approach. Further, we used a host-directed immune target screening to identify the NF-κB and NLRP3 cocktail SB_NI_112 (or NI112 for short) as a targeted inflammasome inhibitor. We used these top two microbe- and host-targeted Nanoligomer cocktails in acute and chronic dextran sulfate sodium (DSS) mouse colitis and in TNF^ΔARE/+ transgenic mice that develop spontaneous Crohn’s like ileitis. The mouse microbiome was humanized to replicate that in human IBD through antibiotic treatment, followed by mixed fecal gavage from 10 human donors and spiked with IBD-inducing microbial species. Following colonization, colitis was induced in mice using 1 week of 3% DSS (acute) or 6 weeks of 3 rounds of 2.5% DSS induction for a week followed by 1 week of no DSS (chronic colitis model). Both Nanoligomer cocktails (CK1 and NI112) showed a strong reduction in disease severity, significant improvement in disease histopathology, and profound downregulation of disease biomarkers in colon tissue, as assessed by multiplexed ELISA. Further, we used two different formulations of intraperitoneal injections (IP) and Nanoligomer pills in the chronic DSS colitis model. Although both formulations were highly effective, the oral pill formulation demonstrated a greater reduction in biochemical markers compared to IP. A similar therapeutic effect was observed in the TNF^ΔARE/+ model. Overall, these results point to the potential for further development and testing of this inflammasome-targeting host-directed therapy (NI112) and more personalized microbiome cocktails (CK1) for patients with recalcitrant IBD.