A monoclonal antibody (mAb), AD1, was isolated that recognized a cell surface protein on rat basophilic leukemia cells (RBL-2H3). At high concentration, this antibody inhibited IgE-mediated but not calcium ionophore-induced histamine release (49% inhibition at 100 micrograms/ml). The mAb AD1 did not inhibit the binding of IgE or of several antibodies directed to the high affinity IgE receptor (...

Asthma is a manifestation of bronchial hyperreactivity (BHR) and forms part of the spectrum of atopic disease. Some pedigree studies of atopy have suggested linkage with the high-affinity IgE receptor (Fc epsilon RI beta) gene on chromosome 11q13, but others find no linkage. The molecular genetics of asthma and BHR have not been studied in the general population. We examined the genetic linkage...

BACKGROUND Fc epsilon RI plays a central role in atopy, thus genetic variants of Fc epsilon RI-beta may alter receptor function to enhance atopic responses and may manifest as a more severe atopic phenotype and more symptomatic atopic disease. The immunological and clinical features of atopy in children with and without the Leu 181 variant of Fc epsilon RI-beta were compared. METHODS Sixty Br...

Aggregation of the receptor with high affinity for IgE (Fc epsilon RI) on the surface of mast cells and basophils stimulates phosphorylation of protein tyrosines, a process in which p53/56lyn kinase has been implicated. We measured the association between Fc epsilon RI and the kinase, using chemical crosslinking to stabilize their interaction. In the rat basophilic leukemia mast cell line, 3-4%...

The binding of immunoglobulin E (IgE) to high affinity IgE receptors (Fc(epsilon)RI) expressed on the surface of mast cells primes these cells to secrete, upon subsequent exposure to specific antigen, a panel of proinflammatory mediators, which includes cytokines that can also have immunoregulatory activities. This IgE- and antigen-specific mast cell activation and mediator production is though...

The high affinity immunoglobulin G (IgG) receptor Fc gamma RI (CD64) is expressed constitutively on monocytes and macrophages, and is inducible on neutrophils. Fc gamma RI has recently been shown to be associated with the signal transducing gamma subunit of the high-affinity IgE receptor (Fc epsilon RI gamma). Induction of cytoplasmic protein tyrosine phosphorylation by Fc gamma RI cross-linkin...

Immediate hypersensitivity is due to the release of mediators from mast cells and basophils after the crosslinking of Fc epsilon RI. The appearance of such receptors was examined during differentiation of human and mouse bone marrow cells cultured in the presence of IL-3. As already reported, mouse bone marrow yield cultures of greater than 95% mast cells by 3 wk, whereas human bone marrow deve...

Cultivation of CD4-CD8- double negative (DN) mouse thymocytes and splenocytes with recombinant interleukin 2 (IL2) in the absence of other stimulation results in the generation of DN-CD3/TCR+CD16+NK1.1+B220+ large granular lymphocytes (LGL). Purified DN alpha-beta TCR+ thymocytes and splenocytes are CD16+IL2R alpha-IL2R beta+NK1.1+B220-CD5high. These cells are unique in that they express both C...

In addition to their well characterized high affinity immunoglobulin E (IgE) receptors (Fc epsilon RI) mast cells have long been suspected to express undefined Fc receptors capable of binding IgE with low affinity. In this paper, we show that Fc gamma RII and Fc gamma RIII, but not Mac-2, on mouse mast cells and macrophages bind IgE-immune complexes. This binding is efficiently competed by 2.4G...

Engagement of the high affinity IgE receptor (FcepsilonRI) in mast cells elicits a series of intracellular signalling events including cytoskeletal reorganization and granule exocytosis. To analyze the coupling of receptor activation to specific cytoskeletal responses, we expressed dominant negative mutant forms of the Rho GTPases CDC42 and Rac1 in rat RBL-2H3 tumor mast cells. We show here tha...