S. Lantero et al., Stimulation of eosinophil IgE low-affinity receptor leads to increased adhesion molecule expression and cell migration, EUR RESP J, 16(5), 2000, pp. 940-946
Immunoglobulin binding on eosinophil surface receptors results in activatio
n of these cells. Evaluating blood eosinophils from atopic subjects, it was
investigated whether ligation of immunoglobulin E low-affinity receptor (F
c epsilon RII/CD23) with specific monoclonal antibodies (Mabs) resulted in
enhanced eosinophil migration and adhesion molecule expression.
Eosinophils from 20 subjects with allergic asthma (atopic individuals) and
nine nonatopic normal individuals (controls) were purified using Percoll gr
adients. The effect of antihuman CD23 Mabs on: 1) eosinophil migration thro
ugh human umbilical vein endothelial cells (HUVECs); and 2) eosinophil expr
ession of the adhesion molecules leukocyte function-associated antigen-1 (L
FA-1, CD11a/CD18), macrophage antigen-1 (Mac-1, CD11b/CD18) and very late a
ctivation antigen-1 (VLA-1, CD49d/CD29) was evaluated by specific Mab stain
ing and flow cytometric analysis.
As compared to controls, freshly isolated eosinophils from atopic individua
ls showed enhanced migration through HUVECs (p<0.05) and increased LFA-1 ex
pression (p<0.01), but similar Mac-1 and VLA-4 expression (p>0.1 for both).
In both controls and atopic individuals, eosinophil incubation,vith antihu
man CD23 Mabs induced a dose-dependent increase in cell migration through H
UVECs, significant at antihuman CD23 Mab concentrations of 5 mug.mL(-1) (p>
0.05 for all). Similarly, incubation of the cells with antihuman CD23 Mabs
induced dose-dependent upregulation of LFA-1 and Mac-1 expression, whereas
no changes in VLA-4 expression were observed (p>0.1). Finally, the enhanced
eosinophil migration induced by antihuman CD23 Mab stimulation was signifi
cantly inhibited by antihuman LFA-1 (84+/-14% (mean+/-SEM); p<0.01) and VLA
-4 Mabs (47+/-15%; p<0.05) but not by antihuman Mac-1 Mabs (p>0.1).
In both atopic and control subjects, immunoglobulin E, low-affinity recepto
r stimulation induces functional changes in eosinophils characterized by in
creased eosinophil migration associated with enhanced late function antigen
-1 and Mac-1 expression.