Expression of Fc(epsilon)-receptors by human acute myelogenous leukemia (AML) blasts: studies of high- and low- (CD23) affinity receptor expression and the effects of IgE-mediated receptor ligation on functional AML blast characteristics.
Acute myelogenous leukemia (AML) blasts derived from 20 patients were examined for expression of high- (Fc(epsilon)RI) and low-affinity (Fc(epsilon)RII, CD23) IgE Fc(epsilon)-receptors. Fc(epsilon)RI expression was not detected for any patient. In contrast, expression of CD23 (at least 15% of the blasts stained positive) was detected for 6 out of the 20 patients. Acute lymphoblastic leukemia (ALL) blasts derived from 12 patients did not express CD23 (<1% positive cells for all patients). The functional effects of Fc(epsilon)R-receptor ligation were also examined for 20 patients, including the five patients with highest CD23 expression (30-55% positive cells) and five patients with verified low CD23 expression (<or=7% positive cells). The presence of IgE during in vitro culture altered the functional characteristics (spontaneous and cytokine-dependent proliferation, colony formation, cytokine secretion, or spontaneous in vitro apoptosis) of AML blasts for a subset of both CD23-positive patients and certain patients with very low CD23 expression. This last observation suggests that Fc(epsilon)R are either expressed at a very low level or receptors are expressed only by a minor cell subset for these patients. We conclude that functional Fc(epsilon)R can be expressed by human AML cells.
Bruserud
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Division for Hematology, Medical Department, The Gade Institute, Haukeland University Hospital, University of Bergen, N-5021 Bergen, Norway. oystein.bruserud@haukeland.no
Gjertsen
B T
BT
Ulvestad
E
E
D017209:Apoptosis; D001752:Blast Crisis / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007073:Immunoglobulin E / Q000494:pharmacology*; D015470:Leukemia, Myeloid, Acute / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D018365:Neoplasm, Residual; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism; D017455:Receptors, IgE / Q000032:analysis*
D017455:Receptors, IgE; D007073:Immunoglobulin E