In:
The Journal of Immunology, The American Association of Immunologists, Vol. 172, No. 12 ( 2004-06-15), p. 7721-7725
Abstract:
Constitutive expression of the pro-molecule of IL-16 has been found in T cells, mast cells, eosinophils, epithelial cells, fibroblasts, and dendritic cells. Here we show that IL-16 is also constitutively present in & gt;98% of freshly isolated human CD14-positive peripheral blood monocytes when analyzed by flow cytometry. Because pro-IL-16 is cleaved to its bioactive mature form by caspase-3, and caspase-3 is also the pivotal effector of apoptosis in monocytes, we asked whether IL-16 release occurs in monocytes that undergo spontaneous apoptosis. As expected, freshly isolated, unstimulated monocytes underwent spontaneous caspase-3 activation. This apoptosis was paralleled by the loss of intracellular IL-16, as detected by flow cytometry, and the concurrent release of IL-16, as detected by ELISA. In contrast, stimulation with bacterial LPS inhibited caspase-3 activation and significantly inhibited the release of IL-16. As a specificity control, IL-1β and IL-8 were not released during spontaneous monocyte apoptosis. In summary, our data demonstrate that monocytes contain IL-16 that is released during spontaneous apoptosis.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.172.12.7721
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2004
detail.hit.zdb_id:
1475085-5
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