Cells of the mucosal mast cell line, RBL-2H3, are normally stimulated to degranulate after aggregation of high affinity receptors for IgE (Fc epsilon RI) by soluble cross-linking ligands. This cellular degranulation process requires sustained elevation of cytoplasmic Ca2+. In this study, we investigated the response of RBL-2H3 cells to 6-micron beads coated with IgE-specific ligands. These liga...

Cytokines, IL-2, IL-4, IL-6, IL-7, IL-12, and IL-15 are key regulators of human peripheral blood T and NK cell activation and differentiation but the precise mechanisms that give rise to their differential activities within these cells are not clear. Recent studies reveal that a family of transcription factors, signal transducers and activators of transcription (STATs) directly mediate many cyt...

The genetic linkage of atopy to chromosome 11q13 through maternally derived alleles has been previously reported. Linkage analysis in Japanese families did not confirm the existence of a major gene for atopy at this locus under the model of autosomal dominant inheritance. However, we observed a significant association between serum total IgE levels and genetic markers at this locus both in 14 J...

Expression of the Fc receptor for IgE (Fc epsilon R) was analyzed on alveolar macrophages (AM) in 10 patients with extrinsic allergic alveolitis (EAA) compared with 10 patients with sarcoidosis and to 6 apparently healthy controls. By using the anti-Fc epsilon RII mAb M-L25 in immunocytochemistry experiments, we found that greater than 60% of AM in 10 of 10 patients with EAA were strongly posit...

Immunoglobulin E (IgE) plays a central role in the pathogenesis of immediate hypersensitivity reactions because of its capacity to bind specifically to high-affinity IgE receptors on mast cells or basophiles by the alpha chain of Fc epsilon receptor type I (Fc-epsilon RI-α).1 In addition to its ability to activate mast calls and basophiles, IgE can bind to the low-affinity IgE receptor (CD23, o...

The dual function of eosinophils has been evidenced in protective immunity against parasites as well as in pathological manifestations during allergic disorders. We have demonstrated that a new class of IgE receptors, Fc epsilon RII/CD23, was involved in the functional duality of eosinophils and other proinflammatory cells. More recently, we have shown that Fc epsilon RI, the high affinity IgE ...

Human rIL-4 and human rIFN-gamma are able to induce the expression of the low affinity receptor for IgE (Fc epsilon R2/CD23) on normal human epidermal Langerhans cells, whereas IL-2 and PMA have no effect. A synergistic effect is observed when both cytokines are combined. These receptors are synthesized de novo by the LC since cycloheximide completely inhibits the appearance of Fc epsilon R2/CD...

To show that macrophages can be effectively targeted against malignant B cells, bispecific antibodies (BsAb) were constructed from two antibodies having specificity for the high-affinity Fc receptor for IgG (Fc gamma RI/CD64) and the B-cell differentiation antigens CD19 and CD37. Using a flow cytometry-based assay and confocal imaging, we show that these constructs mediated significant phagocyt...