The CD27 Ag is expressed by the majority of resting T lymphocytes and appears to play a crucial role in T cell activation. We found that some resting peripheral blood NK cells also express CD27. Furthermore, CD27 expression was up-regulated on NK cells stimulated by IL-2. The cytolytic activity of IL-2-activated, but not resting, NK cells was inhibited by an anti-CD27 mAb (anti-1A4). However, anti-1A4 did not affect conjugate formation between IL-2-activated NK cells and tumor cell targets. In contrast, anti-1A4 inhibited CD2-mediated calcium mobilization and the serine esterase activity of NK cell granules. These inhibitory effects could be mediated in part by increase in intracellular cAMP levels induced by anti- 1A4. Our results suggest that the CD27 Ag plays an important role in the regulation of activated NK cells.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1992|
ASJC Scopus subject areas
- Immunology and Allergy