Premium
Cytoplasmic Calcium Fluxes Induced in Cytotoxic Effector Cells by Engagement of Fcγ Receptors I, II, and III
Author(s) -
CURNOW S. J.,
GLENNIE M. J.,
STEVENSON G. T.
Publication year - 1992
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1992.tb03094.x
Subject(s) - cytotoxic t cell , receptor , effector , antibody , cytotoxicity , microbiology and biotechnology , intracellular , monoclonal antibody , biology , fc receptor , cytoplasm , chemistry , immunology , biochemistry , in vitro
Changes in the intracellular calcium ion concentration ([Ca 2+ ] i ) of monocytes. granulocytes. and NK eells have been studied following either (1) independent cross‐linking of Fcγ receptors (FcγR) I, H, or III, with F(abγ') 2 fragments of monoclonal antibodies: or (2) linking ofa selected FcγR to a tumour cell target with bispecilic F(ab'γ) 2 antibodies. Upon cross‐linking each FcγR with antibody an increase in the ([Ca 2+ ] i ), was observed, although all receptors apart from FcγRIII on NK cells required additional cross‐linking with an anti‐mouse Fab', These results indicale that each type of receptor can transduce signals to the cell independently, Bispecific antibodies (anti‐FcyR X anti‐target) linking cytotoxic FcyR‐bearing effector cells to tumour target cells also mediated increases in ([Ca 2+ ] i ) for all FcγR tested except for FcγRIII on granulocytes. The failure to transduce a signal via ihis receptor may be related to the GPI link, which is in contrast to the transmembrane link of Fcγ RIII on NK cells. Significant lysis of tumour cell targets occurred when bispecific antibodies recruited NK cells or monocytes. bul not granulocytes, via FcγR. Chelation of intracellular Ca 2+ i in the effector cells redueed the observed lysis, suggesting a role for Ca 2+ i in the pathways leading to cytotoxicity.