Soluble fragments of the low-affinity IgE receptor (CD23) inhibit the spontaneous migration of U937 monocytic cells: neutralization of MIF-activity by a CD23 antibody.
U937 monocytic cells were found to respond by diminished spontaneous migration when confronted with affinity-purified soluble fragments of the low-affinity receptor for IgE (FcER2/CD23). Unlike B lymphoma cells, U937 cells could not be activated to respond with enhanced DNA synthesis through their membrane-bound CD23 antigen by MHM6, a monoclonal antibody within the CD23 cluster. MHM6 did, however, effectively neutralize the U937-directed MIF (migration inhibition factor) activity contained within the soluble CD23 preparations. The findings not only suggest a role for soluble CD23 as a novel cytokine at sites of inflammation but also indicate different functions for the membrane-bound forms expressed on B cells and monocytes.
Flores-Romo
L
L
Department of Immunology, University of Birmingham, U.K.
Cairns
J A
JA
Millsum
M J
MJ
Gordon
J
J
D000911:Antibodies, Monoclonal / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology*; D002464:Cell Migration Inhibition; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007961:Leukocyte Migration-Inhibitory Factors / Q000037:antagonists & inhibitors*; D008222:Lymphokines / Q000037:antagonists & inhibitors*; D009000:Monocytes / Q000502:physiology*; D010446:Peptide Fragments / Q000276:immunology; D011961:Receptors, Fc / Q000276:immunology*; D017455:Receptors, IgE; D012995:Solubility
D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D007961:Leukocyte Migration-Inhibitory Factors; D008222:Lymphokines; D010446:Peptide Fragments; D011961:Receptors, Fc; D017455:Receptors, IgE; D007073:Immunoglobulin E