Presenting Author:

Matthew Bury

Principal Investigator:

Arun Sharma

Department:

Urology

Keywords:

Crohn's disease, ileitis, inflammation, nanomolecules, peptide amphiphilies, innate immune cells, adaptive immune cells

Location:

Third Floor, Feinberg Pavilion, Northwestern Memorial Hospital

B180 - Basic Science

Anti-inflammatory Nanomolecules to Modulate Inflammation in Crohn's Disease

Background: Crohn’s disease (CD) is in-part due to a highly pro-inflammatory lesion microenvironment whose progression is accompanied by numerous clinical complications. Current treatment options for CD patients include biologic/pharmacologic anti-inflammatory therapies that are associated with deleterious side effects. Patients refractory to therapeutic treatment typically require surgical intervention and approximately 70% of patients with CD will require surgery during their lifetime. We propose the direct injection of supramolecular nanofibers in the form of anti-inflammatory peptide amphiphiles (AIF-PA) into developing lesions in an established mouse model of ileitis capable of mimicking human CD that will positively modulate the inflammatory microenvironment. Methods: PAs expressing an anti-inflammatory peptide (AIF-PA1) or scrambled peptide sequence control (AIF-PAC) were synthesized and characterized. SAMP1/YitFcsJ mice (n=4 female animals; 10 weeks old) underwent surgery to expose inflammatory lesions on the ileum. Lesions (4 lesions/animal) were independently injected once (100µl) with either saline (SAL), AIF-PA1, or AIF-PAC (2 weight % for AIF-PAs). Lesion size pre/post-injections were evaluated. Animals were sacrificed at 15 weeks and intestinal tissue was harvested. Subsequent tissue sections were single-stained with immunofluorescent antibodies for inflammatory cells CD68 (macrophages), MCT (mast cells), CD4 (T-cells), and cytokines TNFα, IFNγ, IL1β, IL-13, and IL-10. Quantitative morphometric analyses were performed on stained tissue sections using ImageJ (n=3 images/lesion). Results: Quantified morphometric data represented as percent positive cell or cytokine marker derived from tissue staining experiments demonstrated significant decreases in key inflammatory events under SAL vs AIF-PAC vs AIF-PA1 conditions. Specifically: CD68 (88.5±2.6 vs 85.3±1.7 vs 32.6±1.0); MCT (14.4±2.3 vs 13.8±0.7 vs 3.8±0.6); CD4 (34.0±2.3 vs 30.7±1.4 vs 11.6±0.4); TNFα (94.4±0.5 vs 94.2±1.4 vs 62.3±1.8); IFNγ (92.2±1.3 vs 88.7±1.4 vs 56.1±2.9); IL1β (73.3±2.0 vs 70.1±1.4 vs 58.3±3.6); IL-13 (90.3±2.8 vs 89.4±0.7 vs 72.6±2.8). This was accompanied by an increase in IL-10 expression (0.4±0.2 vs 1.2±0.3 vs 5.2±0.7) and a decrease in lesion size (1.50±0.07 mm2 vs 1.42±0.05 mm2 vs 0.74±0.02 mm2). Conclusion: Chronic intestinal exposure to inflammatory factors exhibited in CD contribute to tissue destruction and impair tissue wound healing. Within the context of our study, we demonstrate that a novel AIF-PA can significantly decreases the presence of and down-regulate the expression of pro-inflammatory related cells and cytokines, respectively, in vivo. AIF-PAs may provide a non-toxic, alternative option for those with CD as treatment also reduces lesion size and promotes wound healing via the upregulation of the pro-regenerative cytokine IL-10.