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.
Atopic dermatitis (AD) is the most common chronic inflammatory skin disease, characterized by a Th2/ILC2-dominant immune axis that has become a template for understanding type 2 inflammation across atopic conditions including asthma, eosinophilic esophagitis, and chronic rhinosinusitis with nasal polyps. The approval of dupilumab (anti-IL-4Rα), tralokinumab (anti-IL-13), and subsequent IL-31, IL-33, and TSLP pathway inhibitors has established AD as a highly active indication for biologic development. Peripheral blood PBMCs from AD donors carry the circulating counterpart of the type 2 skewed skin immune response, providing ILC2-enriched, Th2-elevated, and Treg-suppressed profiles relevant to the full spectrum of atopic disease biologics.
Type 2 Immune Axis in AD and Therapeutic Implications
TSLP and IL-33 from keratinocytes activate ILC2s and Th2 cells to produce IL-4, IL-13, and IL-31. IL-4 and IL-13 signal through shared IL-4Rα, driving IgE class switching in B cells, barrier disruption, and itch sensitization. IL-31 directly activates itch neurons. The systemic atopic march (AD → allergic asthma → food allergy) reflects shared type 2 immune activation, and PBMCs from AD donors carry the circulating ILC2, Th2, and IgE-class-switched B cell populations that underlie this systemic phenotype.
OrganaBio Atopic Dermatitis Donor Catalog
| Attribute | Available |
|---|---|
| Disease severity | Mild, moderate, severe (IGA/EASI score documented on select lots) |
| Total IgE | ✓ Documented per lot; IgE-high and IgE-low AD selectable |
| Atopic comorbidities | Asthma, allergic rhinitis, food allergy co-occurrence documented |
| Treatment status | Dupilumab, tralokinumab, JAK inhibitor-treated, and biologic-naive documented |
| PBMC format | Cryopreserved; fresh on scheduled collection |
| Lot documentation | CoA, total IgE, severity score, comorbidities, treatment, flow cytometry |
Key Cell Populations for AD Research
- ILC2s (Lin–/CRTH2+/ST2+): Primary IL-4, IL-5, IL-13 producers activated by TSLP and IL-33; elevated in peripheral blood of AD donors; primary target of anti-TSLP (tezepelumab in atopic march context), anti-IL-33 (itepekimab)
- Th2 cells (CD4+/GATA3+): Expanded in AD; IL-4, IL-13, IL-5 producers; dupilumab target (IL-4Rα blocks both IL-4 and IL-13 signaling)
- IgE-class-switched B cells and plasmablasts: Elevated total and allergen-specific IgE; IgE-FcεRI crosslinking on mast cells drives late-phase reactions; B cell target of anti-IL-4Rα therapies through disrupted IL-4-mediated class switching
- Eosinophils (in circulation): Elevated in moderate-to-severe AD and atopic comorbidities; IL-5 and eotaxin-mediated; relevant to anti-IL-5 programs and eosinophilic overlap phenotypes
- Regulatory T cells: Numerically present but suppressive function impaired in active AD; Treg restoration is a pharmacodynamic endpoint for several pipeline candidates
Research Applications
- IL-4Rα blockade pharmacodynamics: dupilumab effect on ILC2, Th2, and IgE-class-switched B cells in AD PBMCs
- Anti-IL-13 (tralokinumab, cendakimab) and anti-IL-31 (nemolizumab) mechanistic assays in AD PBMCs
- TSLP and IL-33 pathway activation: ILC2 and Th2 response to epithelial cytokine stimulation in AD vs. healthy donor PBMCs
- JAK inhibitor (upadacitinib, abrocitinib, ruxolitinib cream) target engagement: STAT6/STAT3 phosphorylation and type 2 cytokine suppression in AD PBMCs
- Total IgE-stratified immune profiling for IgE-high vs. IgE-low phenotypic differences in effector cell responses
- Atopic march modeling: PBMCs from donors with AD plus asthma or food allergy comorbidities for multi-indication type 2 biology