IgE receptor on human eosinophils (FcERII). Comparison with B cell CD23 and association with an adhesion molecule.
IgE FcR (FcERII) on human eosinophils was characterized and compared with FcERII present on B cells (CD23). Two mAb, BB10 (anti-eosinophil FcERII) and 135 (anti-CD23), bound to the major component of FcERII at 45,000 to 50,000 Mr, both on purified hypodense eosinophils and on a B cell line (WIL-2WT). The specific ligand, human myeloma IgE, was able to bind to the molecules immunoprecipitated by BB10. A cross-reactivity between BB10 and a mAb anti-Leishmania gp63, which is a "fibronectin (Fn)-like" molecule, containing the L-arginine-L-glycyl-L-aspartyl (RGD) cell attachment domain indicated the presence of such a sequence in the common structure present on eosinophil and B cell FcERII. The synthetic tetrapeptide RGDS as well as its inverted sequence (SDGR) reduced the binding of BB10 and anti-Fn mAb to eosinophils and B cells. Flow microfluorometry analysis revealed a variable binding of BB10 and anti-Fn mAb to eosinophils purified from different patients, results compatible with recent findings on the inducibility of FcERIIb. The significant inhibition of IgE-dependent cytotoxicity against parasite targets by preincubation of eosinophils with BB10, anti-Fn and anti-CD23 mAb, with anti-RGDS polyclonal antibodies or with the SDGR peptide suggested the requirement of this cell adhesion sequence for the function of low affinity FcERII. The presence of such a sequence in the C-terminal domain of B cell FcERII raised the possibility of its role in B cell adhesion or B cell growth.
Grangette
C
C
Centre d'Immunologie et de Biologie Parasitaire, Institut Pasteur Lille, France.
Gruart
V
V
Ouaissi
M A
MA
Rizvi
F
F
Delespesse
G
G
Capron
A
A
Capron
M
M
D000595:Amino Acid Sequence; D000944:Antigens, Differentiation, B-Lymphocyte; D001402:B-Lymphocytes / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000032:analysis*; D002460:Cell Line; D004804:Eosinophils / Q000378:metabolism*; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000302:isolation & purification / Q000502:physiology; D011961:Receptors, Fc / Q000032:analysis*; D017455:Receptors, IgE
D000944:Antigens, Differentiation, B-Lymphocyte; D015815:Cell Adhesion Molecules; D009842:Oligopeptides; D011961:Receptors, Fc; D017455:Receptors, IgE; D007073:Immunoglobulin E; C046617:arginyl-glycyl-aspartyl-serine