|
||
J. Exp. Med.,
Volume 188, Number 12, December 21, 1998 2375-2380
By
From the Jefferson Medical College, Department of Microbiology and Immunology, Kimmel Cancer
Institute, Philadelphia, Pennsylvania 19107
Mature natural killer (NK) cells use Ca2+-dependent granule exocytosis and release of cytotoxic proteins, Fas ligand (FasL), and membrane-bound or secreted cytokines (tumor necrosis
factor [TNF]-
) to induce target cell death. Fas belongs to the TNF receptor family of molecules, containing a conserved intracytoplasmic "death domain" that indirectly activates the
caspase enzymatic cascade and ultimately apoptotic mechanisms in numerous cell types. Two additional members of this family, DR4 and DR5, transduce apoptotic signals upon binding
soluble TNF-related apoptosis-inducing ligand (TRAIL) that, like FasL, belongs to the growing TNF family of molecules. Here, we report that TRAIL produced or expressed by different
populations of primary human NK cells is functional, and represents a marker of differentiation
or activation of these, and possibly other, cytotoxic leukocytes. During differentiation NK
cells, sequentially and differentially, use distinct members of the TNF family or granule exocytosis to mediate target cell death. Phenotypically immature CD161+/CD56
NK cells mediate
TRAIL-dependent but not FasL- or granule release-dependent cytotoxicity, whereas mature
CD56+ NK cells mediate the latter two.
This article has been cited by other articles:
| TABLE OF CONTENTS |
|