Reviewed by Sarah Alter, Ph.D. — Scientific Affairs, OrganaBio. 15 years of immunology research spanning autoimmunity, cancer, and infectious disease. University of Miami Miller School of Medicine. Registered Patent Agent.
Ulcerative colitis (UC) is an inflammatory bowel disease restricted to the colonic mucosa, driven by a predominantly Th2 and IL-13-mediated immune axis that distinguishes it from the transmural Th1/Th17 pathology of Crohn’s disease. Peripheral blood from UC donors reflects this mucosal immune activation, with elevated circulating Th2 and Th17 populations, altered ILC2 frequencies, and memory T cell populations primed toward colonic homing that are relevant to biologics targeting IL-13, IL-23, integrin α4β7, and JAK pathways.
Immune Basis of UC Relevant to Drug Discovery
The IL-13/STAT6 axis drives mucosal barrier disruption in UC, with ILC2s and Th2 cells as primary sources. IL-23-driven Th17 expansion is also prominent, making anti-IL-23p19 agents (risankizumab, mirikizumab, guselkumab) active in UC. The integrin α4β7 pathway governs T cell and plasma cell trafficking to the gut mucosa; vedolizumab blocks this and produces a gut-selective anti-inflammatory effect measurable through circulating α4β7+ T cell changes. JAK inhibition (tofacitinib, upadacitinib, filgotinib) reduces global cytokine signaling in a treatment-sensitive manner that is detectable in PBMC cytokine profiles.
OrganaBio UC Donor Catalog
| Attribute | Available |
|---|---|
| Disease activity | Active disease and remission donors documented |
| Treatment status | Biologic-naïve, anti-TNF, vedolizumab, and JAK inhibitor-treated |
| Disease extent | Proctitis, left-sided, extensive/pancolitis on select lots |
| PBMC format | Cryopreserved; fresh on scheduled collection |
| Lot documentation | CoA, diagnosis, Mayo score where available, medications, flow cytometry |
Key Cell Populations for UC Research
- ILC2s (Lin–/CRTH2+): Elevated in active UC; primary source of IL-13 driving epithelial barrier dysfunction and goblet cell loss
- Th2 cells (CD4+/GATA3+): IL-13, IL-4, IL-5 secretion; elevated relative to Crohn’s; target of anti-IL-13 approaches
- Th17 cells (CD4+/RORγt+): IL-17A and IL-22 production; co-elevated in moderate-to-severe UC; anti-IL-23 therapy target
- α4β7+ T cells: Gut-homing integrin expression; pharmacodynamic marker for vedolizumab; frequency shifts with anti-integrin treatment
- Regulatory T cells: Impaired mucosal Treg function in active UC; peripheral Treg frequency measurable as treatment response marker
- Memory B cells and IgA+ plasmablasts: Elevated mucosal IgA production in active UC; peripheral plasmablast frequency reflects disease activity
Research Applications
- Pharmacodynamic assay development for anti-IL-13 (cendakimab, tralokinumab in IBD contexts) and anti-IL-23p19 (mirikizumab, risankizumab) biologics
- α4β7 integrin occupancy and T cell trafficking studies for vedolizumab and next-generation anti-integrin programs
- JAK inhibitor target engagement: STAT1/STAT3 phosphorylation in stimulated UC PBMCs pre- and post-treatment
- ILC2 biology and IL-13 pathway activation assays
- Mucosal immunity modeling with UC-derived T cell populations co-cultured with epithelial organoids
- Biomarker discovery: fecal calprotectin correlation with peripheral immune activation markers