OP23 Neutrophil Niches and Therapy Resistance in Ulcerative Colitis: Spatial Atlas Insights

Abstract Background Resistance to tumor necrosis factor inhibitor (TNFi) therapy remains a major obstacle in managing ulcerative colitis (UC), affecting up to 50% of patients.1 The complex interplay of immune cells and their spatial organization in the gut mucosa is poorly understood but likely contributes to therapeutic outcomes.1,2 This study utilized advanced multiplexed imaging to construct a spatial atlas of UC, providing insights into cellular interactions driving TNFi resistance. Novel spatial omic technologies show to be able to add additional thus far unknown insights to this question. Methods A total of 42 tissue regions from 29 UC patients and 5 healthy controls were analyzed using CODEX multiplexed imaging. Spatially resolved single-cell data, encompassing over 1.7 million cells, were used to identify distinct cell types and map cellular neighborhoods (CNs). Pairwise cell-cell contacts and CN-level functional states were analyzed in TNFi-treated and untreated patients, correlating findings with clinical outcomes. Results TNFi therapy led to normalization of adaptive immune CNs, such as lymphoid aggregates, with reductions in T-cell frequencies and associated contacts. However, innate immune CNs, including neutrophil-enriched granulocyte niches and inflamed stroma, remained unchanged despite treatment. Notably, neutrophil-dominated CNs exhibited persistent expression of pro-inflammatory markers, such as TNFR2 and CD137, implicating these niches in sustaining mucosal inflammation and therapy resistance. Additionally, sex-dependent differences were observed, with higher TNFi responsiveness in females potentially linked to adaptive immune modulation.3 Conclusion Neutrophil-dominated inflammatory niches represent a potential mechanism of TNFi resistance in UC.3,4 These findings highlight the importance of targeting innate immune pathways alongside TNFi therapy to improve outcomes. By integrating spatial insights with functional data, this study paves the way for precision medicine approaches in UC management. References 1.R. Ungaro, S. Mehandru, P. B. Allen, L. Peyrin-Biroulet, J.-F. Colombel, Ulcerative colitis.Lancet 389, 1756–1770 (2017). 2.R. Gaujoux, E. Starosvetsky, N. Maimon, F. Vallania, H. Bar-Yoseph, S. Pressman, R. Weisshof,I. Goren, K. Rabinowitz, M. Waterman, H. Yanai, I. Dotan, E. Sabo, Y. Chowers, P. Khatri,S. S. Shen-Orr; Israeli IBD research Network (IIRN), Cell-centred meta-analysis revealsbaseline predictors of anti-TNFα non-response in biopsy and blood of patients with IBD.Gut 68, 604–614 (2019). 3.A.T. Mayer, D.R. Holman, A. Sood, U. Tandon, S. S. Bhate, S. Bodapati, G. L. Barlow, J. Chang, S. Black, E. C. Crenshaw, A. N. Koron, S. E. Streett, S. S. Gambhir SS, W. J. Sandborn, B. S. Boland, T. Hastie, R. Tibshirani, J. T. Chang, G. P. Nolan, C. M. Schürch, S. Rogalla “A tissue atlas of ulcerative colitis revealing evidence of sex-dependent differences in disease-driving inflammatory cell types and resistance to TNF inhibitor therapy” Sci Adv. 2023 Jan 20;9(3):eadd1166. doi: 10.1126/sciadv.add1166. Epub 2023 Jan 20. 4.S. T. Eshghi, J. M. Gubatan, P. Mazrooei, L. Quintanilla, A. Nguyen, A. Au-Yeung, D. R. Holman, C. Takashi, C. Schiffman, B. O’Gorman, M. Keir, S. Ramanujan, S. Rogalla, J. A. Hackney, J. M McBride “Molecular characterization of response to Etrolizumab and anti-TNF reveals treatment resistance in ulcerative colitis is associated with abundance of residual neutrophil subsets and inflammatory fibroblast populations” https://doi.org/10.1101/2024.07.02.601267