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A novel subset of NK cells expressing high levels of inhibitory FcγRIIB modulating antibody‐dependent function
Author(s) -
Dutertre CharlesAntoine,
BonninGélizé Emmanuelle,
Pulford Karen,
Bourel Dominique,
Fridman WolfHerman,
Teillaud Jean-Luc
Publication year - 2008
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.0608343
Subject(s) - biology , inhibitory postsynaptic potential , function (biology) , antibody , microbiology and biotechnology , immunology , neuroscience
NK cells can kill antibody‐coated target cells following engagement of FcγRIIIA, the major activating FcγR expressed by these cells. The presence of FcγRIIC (CD32C) has also been reported, but its contribution to the FcγR‐dependent effector functions of NK cells remains debated. We demonstrate here that inhibitory FcγRIIB is also expressed by a small subset of CD56 + /NKp46 + NK cells and can efficiently down‐modulate their FcγR‐dependent effector function. Immunofluorescence analyses of NK cells from 52 healthy donors showed the presence of CD56 bright /FcγRII − (5.2%±3.4), CD56 dim /FcγRII lo/‐ (94.1%±3.4), and CD56 dim /FcγRII bright (0.64%±0.72) cells. QRT‐PCR and protein analyses performed on isolated FcγRII bright NK cells indicated that FcγRIIB is strongly expressed by these cells but not by FcγRII lo/‐ cells. In addition, FcγRII bright cells showed a weaker antibody‐dependent degranulation when incubated with IgG‐coated target cells compared with FcγRII lo/‐ NK cells, although a strong FcγRIIIA expression was detected in both cells. Furthermore, the addition of anti‐FcγRII Fab paralleled a higher degranulation of FcγRII bright NK cells, indicating a direct role for FcγRIIB in this down‐modulating effect. Thus, it is proposed that FcγRIIB bright NK cells represent a new NK cell compartment able to down‐modulate NK cell functions triggered by the engagement of activating FcγR.