Differential recruitment of accessory molecules by Fc gamma RI during monocyte differentiation

Cameron, AJM Harnett, MM Allen, JM

Ajm. Cameron et al., Differential recruitment of accessory molecules by Fc gamma RI during monocyte differentiation, EUR J IMMUN, 31(9), 2001, pp. 2718-2725

26

INGLESE

Article

Immunology

EUROPEAN JOURNAL OF IMMUNOLOGY

0014-2980 → ACNP

31

9

2001

2718 - 2725

ISI

0014-2980(200109)31:9<2718:DROAMB>2.0.ZU;2-2

Aggregation of the human high-affinity receptor for immunoglobulin G, Fc ga mma RI, results in initiation of intracellular signaling cascades. However, as the receptor contains no known signaling motif, it is required to recru it an accessory molecule. The gamma chain has been proposed to fulfil this role. Here, we show that in U937 cells differentiated to a more macrophage- like phenotype with dibutyryl cAMP Fc gamma RI no longer signals through th e gamma chain but rather uses Fc gamma IIa to initiate tyrosine phosphoryla tion. Expression of the gamma chain is, however, increased in the dbcAMP-in duced cells, but here the gamma chain specifically associates with the IgA receptor, Fc alpha RI Recruitment of the gamma chain either by Fc gamma RI in cytokine-primed cells or by Fc alpha RI in dbcAMP-induced cells couples ligand binding to the activation of phosphatidyl choline-specific phospholi pase D.