N. Kawata et al., SIGNAL-TRANSDUCTION BY IGG RECEPTORS INDUCES CALCIUM MOBILIZATION, BUT NOT HISTAMINE-RELEASE, IN THE HUMAN BASOPHILIC CELL-LINE KU812F, International archives of allergy and immunology, 109(1), 1996, pp. 27-34
Human blood basophils selectively express Fc gamma RII (CDw32) among I
gG receptor subtypes, but its functional role in allergic reactions re
mains unknown. Using the human basophilic leukemia cell line KU812F as
a model system, we investigated cellular signaling events mediated th
rough IgG receptor stimulation. KU812F cells express Fc gamma RII on t
heir surface. mRNAs for both Fc gamma RIIA and IIB subtypes were detec
ted by reverse transcriptase-PCR analysis. In this cell line, Fc gamma
RII stimulation induced mobilization of free intracellular calcium an
d actin polymerization. Yet, no significant histamine release was obse
rved, nor did blood basophils stimulated by anti-Fc gamma RII monoclon
al antibody IV.3 and by a secondary antibody release histamine. These
data indicate that Fc gamma RII stimulation induces cellular signaling
events such as calcium mobilization in human basophils. However, thes
e events do not lead to histamine release.