B. Fadeel et al., ANTI-FAS IGG1 ANTIBODIES RECOGNIZING THE SAME EPITOPE OF FAS APO-1 MEDIATE DIFFERENT BIOLOGICAL EFFECTS IN-VITRO/, International immunology, 9(2), 1997, pp. 201-209
Fas/APO-1 is a cell surface glycoprotein that mediates programmed cell
death or apoptosis when cross-linked with agonistic anti-fas or anti-
APO-1 mAb or the endogenous Fas/APO-1 ligand, In this report, we exami
ned the in vitro biological properties of a panel of anti-human Fas mA
b of IgG1 subclass (ZB4, VB3, WB3 and CBE), We found that anti-fas clo
ne VB3 induced marked apoptotic cell death in Fas/APO-1-expressing Jur
kat cells, although this cell killing was delayed when compared to the
cytolytic effect mediated by the prototypic anti-fas antibody of IgM
subclass (clone CH-11), The ZB4 antibody, on the other hand, efficient
ly blocked apoptosis induced by CH-11. The WB3 and CBE clones neither
induced or inhibited apoptosis, These antibodies were all found to rec
ognize one and the same linear site on the Fas/APO-1 molecule, despite
their different biological effects, The ability of these anti-fas mAb
to induce or inhibit apoptosis appeared to correlate with their relat
ive affinity for the Fas/APO-1 molecule, These results provide further
evidence for the potential of anti-fas antibodies of the IgG1 subclas
s to elicit signals via the Fas/APO-1 molecule.