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Olyntho, V. M.

Publications and source records attributed to Olyntho, V. M..

2 recordsLinked to original sources

Eosinophil-epithelial interactions mediate protective intestinal remodeling during food allergy

Food allergies are associated with progressive gastrointestinal symptoms driven by exacerbated mucosal type-2 immunity. Here, we investigated whether cellular interactions between the gut epithelium and innate immune cells regulate the severity of allergic symptoms in mice. Using the BALB/c OVA-alum food allergy model, we observed that repeated oral allergen challenges remodel the gut epithelium, expanding tuft cells, while shifting the intestinal stem cell niche toward a fetal-like repair state. Using uLIPSTIC, we systematically characterized in vivo immune-epithelial interactions and found that eosinophils and mast cells directly interact with intestinal epithelial cells (iECs) in an allergen challenge-dependent manner. Epithelial subset-specific uLIPSTIC provided further resolution and revealed that eosinophils and mast cells contact enteroendocrine cells and Paneth cells in a regionally compartmentalized manner. Allergic challenge was associated with rapid eosinophil migration towards the crypts and modulation of iEC differentiation. Depletion of eosinophils using two independent approaches reversed key markers of food allergy-associated epithelial remodeling, while exacerbating allergic diarrhea and mortality from anaphylactic shock. These findings establish eosinophils as orchestrators of protective epithelial remodeling in food allergies.

immunology↗

Immune cells adapt to distinct stem cell niches to govern tissue homeostasis

Summary ParagraphIn adult tissues, epithelial stem cells exist within distinct residences, each endowing them with exclusive instructions for regenerative fitness under homeostasis and stress. Key components of these niches are immune cells, which classically protect the host against external and internal threats. Whether and how stem cell:immune cell crosstalk contributes to normal tissue biology remains less clear. Here, we discover functional adaptation of resident lymphocytes within two distinct skin stem cell niches and show that through this communication, each niche adjusts to meet diverse tissue demands. In the upper hair follicle, where microbial load is high, T cells express lymphotoxin-{beta} and stimulate adjacent receptor-positive epithelial stem cells to form an immune-competent niche that controls microbial expansion. By contrast, in the epidermis, these T cells produce amphiregulin to maintain continuous stem cell reconstitution of the skins barrier. Concomitantly, they express the immune checkpoint protein LAG-3, which autorestricts lymphocyte numbers, and hence amphiregulin levels, thereby preventing over-proliferative responses. Finally, when epidermal T cells are absent, dermal lymphocytes restore the imbalance by colonizing and adapting to their new niche. Our findings unveil functional specialization and homeostatic resilience of immune-stem cell niches, each tailored to suit the demands of distinct tissue microenvironments.

immunology↗