Biology subjects

Itan, M.

Publications and source records attributed to Itan, M..

3 recordsLinked to original sources

bioRxiv2026

Dynamic Regulation of CD300b, and CD300f on Myeloid Cells in Oral Immunotherapy

IntroductionOral immunotherapy (OIT) induces desensitization in IgE-mediated food allergy, yet the role of myeloid cells in acquisition of tolerance is unclear. CD300 receptors regulate activation of myeloid cells, with CD300f acting as an inhibitory receptor and CD300b as an activating receptor. Their modulation during OIT may reflect effector cell reprogramming and serve as biomarkers of treatment response. MethodsThirty-five patients undergoing OIT were prospectively enrolled. Peripheral blood was collected at baseline and first 3 months of up-dosing; 19 patients completed sampling upon reaching maintenance. CD300b and CD300f expression in eosinophils, monocytes, and neutrophils was analyzed by flow cytometry. Allergen-specific IgE and IgG4 were measured by ImmunoCAP. Associations with clinical parameters were assessed using logistic regression. Results. Baseline CD300b was higher in patients with lower starting doses (p[≤]0.05). CD300f expression was lower in those with atopic dermatitis or multiple food allergies (p[≤]0.03). A significant downregulation of CD300b expression in the surface of eosinophils, monocytes, and neutrophils, was noted early in treatment (p[≤]0.05). Expression of CD300f was slightly but non-significantly increased. Longitudinally, the expression of CD300f increased on eosinophils, whereas CD300b expression decreased on the surface of monocytes and neutrophils. Specific IgE reduction correlated with downregulation of CD300b expression in monocytes (R=0.51, p=0.02) and higher CD300f expression in eosinophils (R=-0.45, p=0.05). ConclusionsDownregulation of CD300b and upregulation of CD300f during OIT suggests myeloid cell reprogramming toward a less inflammatory phenotype. These dynamic changes in expression and their correlation with serologic markers of desensitization, suggest CD300b and CD300f as candidate biomarkers for understanding and monitoring OIT response. Key MessageO_LIOIT is associated with downregulation of the activating receptor CD300b and upregulation of the inhibitory receptor CD300f on myeloid cells. C_LIO_LIMyeloid cell reprogramming accompanies OIT, extending immune tolerance beyond adaptive regulatory mechanisms. C_LIO_LICD300b and CD300f expression dynamics correlate with clinical dosing and serologic markers of OIT response. C_LI

immunology↗

bioRxiv2026

Differential roles for IL-4Rα and IL-13Rα1in immune cell infiltration and epithelial remodeling in experimental eosinophilic gastritis

RationaleEosinophilic gastritis (EoG) is a chronic inflammatory disease characterized by infiltration of eosinophils and mast cells, epithelial remodeling, and fibrosis. Although EoG is increasingly recognized as a distinct type 2 inflammatory disease, the cellular and molecular events that drive disease pathogenesis remain poorly understood. This is due in part to the absence of robust and physiologically relevant experimental models that recapitulate human disease. MethodsExperimental EoG was induced in wild type and Il13ra1-/-mice by repeated intragastric oxazolone challenges in skin-sensitized mice. IL-4R1 was neutralized using antibodies. Gastric histopathology was determined by H&E, anti-Ki67, chloroacetate esterase and anti-MBP staining. Gastric RNA was subjected to RNA sequencing. ResultsExperimental EoG resulted in robust gastric eosinophilia, mastocytosis, epithelial remodeling, and subepithelial fibrosis. Transcriptomic profiling of gastric tissue revealed broad upregulation of type 2 cytokine and epithelial-remodeling genes, including Il4ra, Il4i1, Ccl5, Muc4, Mmp10, Mcpt1/2, Areg, Pparg and Tff2. The transcriptome profile of experimental EoG was markedly distinct from that of experimental EoE despite both models being initiated by oxazolone, suggesting that identical inflammatory triggers elicit tissue-specific and context-dependent transcriptional programs. Blockade of IL-4R signaling abrogated both eosinophil and mast cell infiltration and attenuated epithelial remodeling, whereas genetic deletion of Il13ra1 selectively suppressed epithelial remodeling without affecting inflammatory cell recruitment. ConclusionThese findings establish experimental EoG as a robust model for dissecting the cellular and molecular mechanisms driving gastric type 2 inflammation. They further define receptor-specific roles for IL-4R and IL-13R1 in coordinating immune infiltration and epithelial remodeling in EoG.

immunology↗

bioRxiv2025

Distinct roles for thymic stromal lymphopoietin (TSLP) and IL-33 in experimental eosinophilic esophagitis

RationaleThymic stromal lymphopoietin (TSLP) and IL-33 are alarmins implicated in EoE pathogenesis by activating multiple cells including mast cells (MCs). Whether TSLP or IL-33 have a role in EoE and whether their activities are distinct requires further investigation. MethodsExperimental EoE was induced in wild type (WT) Il33-/-and Crlf2-/- mice. TSLP or IL-5 were neutralized using antibodies. Esophageal histopathology was determined by H&E, anti-Ki67, anti-CD31 and anti-MBP staining. Esophageal RNA was subjected to RNA sequencing. Bone marrow-derived MCs were activated with TSLP and IL-13 was determined (ELISA) ResultsTSLP and IL-33 were overexpressed in human and experimental EoE. Human and mouse esophageal MCs displayed the highest level of Crlf2 (TSLPR) compared to other immune cells. Crlf2-/- mice were nearly-completely protected from EoE, and TSLP neutralization resulted in decreased basal cell proliferation, eosinophilia, lamina propria thickening and vascularization. Induction of experimental EoE in Il33-/- mice resulted in reduced eosinophilia but no alterations in tissue remodeling were observed compared to WT mice. RNA sequencing revealed that TSLP regulates the expression of key genes associated with human EoE (e.g. eotaxins, Il19, Klk5, Flg, Il36rn, Il1r2) and suggest a role for TSLP in regulating IL-1 signaling, barrier integrity and epithelial cell differentiation. Experimental EoE was characterized by a MC-associated gene signature and elevated MCs. Activation of MCs with TSLP resulted in secretion of IL-13. ConclusionTSLP and IL-33 have non-redundant functions in experimental EoE. This study highlights TSLP as an upstream regulator of IL-13 and a potential therapeutic target for EoE.

immunology↗