Okadaic acid inhibits secretion from mast cells, suggesting a regulatory role for protein Ser/Thr phosphatases type I (PP1) and/or 2A (PP2A) in the secretory process. In unstimulated RBL-2H3 cells, okadaic acid pretreatment inhibited PP2A activity in both cytosol and membrane fractions, but inhibition of secretion correlated with inhibition of membrane-bound rather than cytosolic PP2A activity....

This study aimed to evaluate the anti-allergic potential of Echium plantagineum L. bee pollen and to characterize its primary metabolites. The activity of E. plantagineum hydromethanolic extract, devoid of alkaloids, was tested against β-hexosaminidase release in rat basophilic leukemic cells (RBL-2H3). Two different stimuli were used: calcium ionophore A23187 and IgE/antigen. Lipoxygenase inhi...

Although the level of serum amyloid A has been reported to be up-regulated during inflammatory response, the role of serum amyloid A on the regulation of inflammation and immune response has not been elucidated. We found that serum amyloid A stimulated the production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10, which are proinflammatory and anti-inflammatory cytokines, respecti...

AIMS Glucosamine has been used safely to relieve osteoarthritis in humans, but the precise mechanism underlying its efficacy is still unclear. In this study, we investigated the direct effects of glucosamine and related compounds on mast cell mediated inflammation using cultured mast cells and an animal model. MAIN METHODS Dinitrophenyl (DNP)-IgE-sensitized rat basophilic leukemia RBL-2H3 cel...

Mast cells are traditionally considered as key effector cells in IgE-mediated allergic diseases. However, the roles of mast cells have also been implicated in diverse physiological and pathological processes. Mast cells are distributed in various organs and tissues of various species. Some of the organs and tissues, such as testis, skin, and the upper part of the respiratory tract, have a tempe...

Investigations of the actions and interactions of the immunophilin ligands FK506, cyclosporin A (CsA), rapamycin, and 506BD suggest that complexes of FK506 with an FK506-binding protein or of CsA with a cyclophilin (CsA-binding protein) inhibit the T-cell receptor-mediated signal transduction that results in the transcription of interleukin 2. Now we report an identical spectrum of activities o...

CD69 and CD23 are leukocyte receptors with distinctive pattern of cell expression and functional features that belong to different C-type lectin receptor subfamilies. To assess the functional equivalence of different domains of these structurally related proteins, a series of CD69/CD23 chimeras exchanging the carbohydrate recognition domain, the neck region, and the transmembrane and cytoplasmi...

Increases in asthma worldwide have been associated epidemiologically with expanding urban air pollution. The mechanistic relationship between airway hyper-responsiveness, inflammation, and ambient airborne triggers remains ambiguous. Acrolein, a ubiquitous aldehyde pollutant, is a product of incomplete combustion reactions. Acrolein is abundant in cigarette smoke, effluent from industrial smoke...

Aspirin is the oldest non-steroidal anti-inflammatory drug (NSAID), and it sometimes causes asthma-like symptoms known as aspirin-exacerbated respiratory disease (AERD), which can be serious. Unwanted effects of aspirin (aspirin intolerance) are also observed in patients with food-dependent exercise-induced anaphylaxis, a type I allergy disease, and aspirin-induced urticaria (AIU). However the ...

We have determined the membrane topography of the high-affinity IgE receptor, FcstraightepsilonRI, and its associated tyrosine kinases, Lyn and Syk, by immunogold labeling and transmission electron microscopic (TEM) analysis of membrane sheets prepared from RBL-2H3 mast cells. The method of Sanan and Anderson (Sanan, D.A., and R.G.W. Anderson. 1991. J. Histochem. Cytochem. 39:1017-1024) was mod...