Human neutrophils express the high-affinity receptor for immunoglobulin E (FcεRI): role in asthma

Abstract

Polymorphonuclear neutrophils (PMNs) are important effector cells in host defense and the inflammatory response to antigen. The involvement of PMNs in inflammation is mediated mainly by the Fc receptor family, including IgE receptors. Recently, PMNs were shown to express two IgE receptors (CD23/Fc epsilon RII and galectin-3). In allergic diseases, the dominant role of IgE has been mainly ascribed to its high-affinity receptor, Fc epsilon RI. We have examined the expression of Fc epsilon RI by PMNS: mRNA and cell surface expression of Fc epsilon RI alpha chain was identified on PMNs from asthmatic subjects. Furthermore, preincubation with human IgE Fc fragment blocks completely the binding of anti-Fc epsilon RI alpha chain (mAb15--1) to human PMNS: Conversely, preincubation of PMNs with mAb15--1 inhibits significantly the binding of IgE Fc fragment to PMNs, indicating that IgE bound to the cell surface of PMNs mainly via the Fc epsilon RI. Peripheral blood and bronchoalveolar lavage (BAL) PMNs from asthmatic subjects also express intracellular Fc epsilon RI alpha and beta chain immunoreactivity. Engagement of Fc epsilon RI induces the release of IL-8 by PMNS: Collectively, these observations provide new evidence that PMNs express the Fc epsilon RI and suggest that these cells may play a role in allergic inflammation through an IgE-dependent activation mechanism.

15-Deoxy-Δ12,1412,14-PGJ2 Induces IL-8 Production in Human T Cells by a Mitogen-Activated Protein Kinase Pathway

“…This increased IL-8 then induces the chemotaxis and subsequent activation of cells such as neutrophils. Neutrophils play a major role in allergic inflammation (46). In fact, the level of neutrophil-mediated inflammation in bronchoalveolar lavage fluid often reflects the severity of asthma in the patient (44).…”

Mouse and human neutrophils induce anaphylaxis

“…All of them express another activating IgG receptor, FcγRIIA. Mast cells and basophils also express the high-affinity IgE receptor FcεRI in normal individuals as well as neutrophils in atopic patients (41). These 3 cell types can produce PAF upon activation, especially neutrophils (21).…”

The high-affinity IgE receptor (FcεRI): a critical regulator of airway smooth muscle cells?

“…For instance, in human antigen-presenting cells, Fc⑀RI is expressed as a trimeric (␣␥ 2 ) complex (8, 74 -76, 81, 107) and as a tetramer (␣␤␥ 2 ) in mast cells (29). However, in the case of human eosinophils (36, 98), platelets (53), and neutrophils (35), although both mRNA and protein for the ␤-chain have been detected, the existence of a functional ␣␥ 2 complex could not be ruled out.…”