DOP068αvβ6 autoantibodies define a myeloid cell enriched, T cell activated, IgG-skewed mucosal phenotype in colonic Inflammatory Bowel Disease

Abstract Background Integrin αvβ6 is an epithelial-specific heterodimer that activates latent TGF-β and maintains mucosal homeostasis. Recent studies have identified anti-αvβ6 autoantibodies (αvβ6-aAbs) in ulcerative colitis (UC) and colonic Crohn’s disease (CD). In patients with UC, αvβ6-aAbs associate with disease activity, complications, and therapy resistance. However, the mucosal immune signatures accompanying αvβ6-aAbs remain undefined. Methods αvβ6-aAbs were quantified by an in-house ELISA in 39 prospectively recruited patients with colonic IBD (cIBD: 18 UC, 11 colonic L2 CD, 10 ileocolonic L3 CD). Seropositivity was defined as log-transformed mean absorbance + 2 standard deviations of healthy controls. Single-cell suspensions from fresh colonic biopsies were analyzed by multiparameter flow cytometry to profile innate and adaptive immune populations. Data were analyzed using Mann-Whitney U and Spearman correlation tests. Results Overall, in patients with cIBD αvβ6-aAb seropositivity was 44% (17/39; UC 61%, CD 29%). When compared to αvβ6 aAb− patients, αvβ6 aAb+ patients demonstrated increased mucosal infiltration by CD66b+CD16+ neutrophils (P = 0.049) and CD14+CD16− monocytes (P = 0.039). Frequencies of activated (CD38+) CD4+ (P = 0.0017) and CD8+ (P = 0.0041) T cells were elevated in αvβ6-aAb+ versus αvβ6-aAb− cIBD, whereas mature (CD27+) B cells were reduced (P = 0.028). Notably, αvβ6-aAb+ patients exhibited an increased IgG+:IgA+ ratio among mature (P = 0.037) and switched-memory (IgD⁻IgM⁻) B cells (P = 0.013). Serum αvβ6-aAb titers correlated positively with mucosal activated CD4+ (ρ = 0.44, P = 0.036) and CD8+ T cells (ρ = 0.44, P = 0.038), as well as with IgG+:IgA+ ratios in mature (ρ = 0.55, P = 0.011) and switched-memory B cells (ρ = 0.58, P = 0.0064), suggesting a link between αvβ6-aAbs, T-cell activation, and IgG-class-switched humoral immunity. Conclusion αvβ6-aAb mark a distinct immunopathologic subset of IBD characterised by enhanced myeloid cell presence, activated T-cell responses and IgG-skewed B-cell responses in the colonic mucosa. These findings provide mechanistic insight into how αvβ6-directed autoimmunity may disrupt epithelial-immune crosstalk, amplify mucosal inflammation, and underlie the adverse clinical outcomes previously linked to αvβ6-aAbs. Conflict of interest: Ceulemans, Matthias: No conflict of interest Acharya, Akanksha: No conflict of interest Tankelevich, Michael: No conflict of interest Jha, Divya: No conflict of interest Kethidi, Nikhit: No conflict of interest Makwana, Katha: No conflict of interest Mercurio, Alana: No conflict of interest Helmus, Drew: No conflict of interest Prasad, Medha: No conflict of interest Cutler, Molly: No conflict of interest Lewis, Kristen: No conflict of interest Marion, James: No conflict of interest Sands, Bruce E: Grant: Janssen Personal Fees: Abivax SA Abbvie Adiso Therapeutics Agomab Therapeutics Alimentiv Amgen AnaptysBio AstraZeneca Biora Therapeutics Boehringer-Ingeleim Bristol Myers Squibb Celltrion, Inc. ClostraBio Cytoki Pharma EcoR1 Capital Eli Lilly and Company Enthera Equilium, Inc. Ensho Therapeutics Evommune Ferring Galapagos Genentech, Inc. Gilead Sciences GlaxoSmithKline Gossamer Bio Imhotex Immunyx Pharma Ltd. Index Pharmaceuticals Innovation Pharmaceuticals Janssen Janssen Biotech Janssen Pharmaceutica NV Janssen Research & Development, LLC Janssen Scientific Affairs, LLC Janssen-Cilag PTY, Ltd. Johnson & Johnson Kaleido Kallyope Kyowa Kirin, Inc. Merck & Co. Microba Microbiotica Limited Mirador Therapeutics Morphic Therapeutic MRM Health NV Palisade Therapeutics Pfizer, Inc. Prometheus Biosciences Prometheus Laboratories Protagonist Therapeutics, Inc. Q32 Bio Sanofi Sorriso Therapeutics Surrozen Takeda Target RWE Teva TLL Pharmaceutical Tr1x Union Therapeutics Ventyx Biosciences Non-financial Support: Janssen, Pfizer, Lilly, Takeda, Bristol Myers Squibb Other: Stock/Stock Options from Ventyx Biosciences Ungaro, Ryan: Personal Fees: AbbVie, Bristol Myers Squibb, Genentech, Lilly, Pfizer, Janssen, Takeda Colombel, Jean-Frédéric: Grant: AbbVie, Janssen Pharmaceuticals, Takeda, Prometheus and Bristol Myers Squibb Lectures from: AbbVie, Roche and Takeda Other: AbbVie, Amgen, AnaptysBio, Allergan, Apini, Arena Pharmaceuticals, Astellas, Boehringer Ingelheim, Bristol Myers Squibb, candidrx Celgene, Celltrion, Clearview Curogen, Eli Lilly, Envision Pharma Ferring Pharmaceuticals, Galmed Research, Glaxo Smith Kline, Roche, Janssen Pharmaceuticals, Kaleido Biosciences, Immunic, Iterative Scopes, Landos, Microba Life Science, Merck, Mirador, Novartis, Otsuka Pharmaceutical, Owkin, Pfizer, Protagonist Therapeutics, Sanofi, Sun Pharma, Takeda, Teva, TiGenix, and is holding stock options in Intestinal Biotech Development Livanos, Alexandra: No conflict of interest Mehandru, Saurabh: Grant: Genentech, Brystol Myers Squib (BMS) Personal Fees: AbbVie, Adacyte, Alimentiv, Atticus, Brystol Myers Squib (BMS), Cabaletta, Georgia Immune, Merck, Novartis