Aryl hydrocarbon receptor controls murine mast cell homeostasis.

We propose that the aryl hydrocarbon receptor (AhR), a unique chemical sensor, is critical in controlling mast cell differentiation, growth, and function in vitro and in vivo. In antigen-stimulated mast cells, exposure to AhR ligands resulted in a calcium- and reactive oxygen species (ROS)-dependent increase of reversible oxidation in and reduced activity of SHP-2 phosphatase, leading to enhanced mast cell signaling, degranulation, and mediator and cytokine release, as well as the in vivo anaphylactic response. Surprisingly, significant mast cell deficiency was noted in AhR-null mice due to defective calcium signaling and mitochondrial function, concomitant with reduced expression of c-kit and cytosolic STAT proteins, as well as enhanced intracellular ROS and apoptosis.

Oral tolerance to food-induced systemic anaphylaxis mediated by the C-type lectin SIGNR1.

We propose that a C-type lectin receptor, SIGNR-1 (also called Cd209b), helps to condition dendritic cells (DCs) in the gastrointestinal lamina propria (LPDCs) for the induction of oral tolerance in a model of food-induced anaphylaxis. Oral delivery of BSA bearing 51 molecules of mannoside (Man(51)-BSA) substantially reduced the BSA-induced anaphylactic response. Man(51)-BSA selectively targeted LPDCs that expressed SIGNR1 and induced the expression of interleukin-10 (IL-10), but not IL-6 or IL-12 p70.

Functional interaction of common allergens and a C-type lectin receptor, dendritic cell-specific ICAM3-grabbing non-integrin (DC-SIGN), on human dendritic cells.

Fucosylated glycans on pathogens are known to shape the immune response through their interaction with pattern recognition receptors, such as C-type lectin receptors (CLRs), on dendritic cells (DCs). Similar fucosylated structures are also commonly found in a variety of allergens, but their functional significance remains unclear. To test a hypothesis that allergen-associated glycans serve as the molecular patterns in functional interaction with CLRs, an enzyme-linked immunosorbent assay-based binding assay was performed to determine the binding activity of purified allergens and allergen extracts.

Shortening of the induction period of allergic asthma in cynomolgus monkeys by Ascaris suum and house dust mite.

The development of non-human primate models of asthma requires a period of time (e.g., 0.

Antigen coupled with Lewis-x trisaccharides elicits potent immune responses in mice.

Background: Glycoproteins containing Lewis-x (Le(x)) trisaccharides are often associated with the host's adaptive T(H)2-type immunity, but the mechanisms underlying the T(H)2-biased response are at present unclear.

Objective: The modulatory effect of Le(x) or its glycoconjugates on IgE/T(H)2 responses was investigated.

Methods: The levels of serum antibodies and cytokines were analyzed by means of ELISA, RT-PCR, or both.