Surface expression of TRAIL/Apo-2 ligand in activated mouse T and B cells

✍ Scribed by Sara M. Mariani; Peter H. Krammer

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 133 KB
• Volume: 28
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/(sici)1521-4141(199805)28:05<1492::aid-immu1492>3.0.co;2-x

✦ Synopsis

Like other members of the TNF family, TRAIL/Apo-2 ligand induces apoptosis in sensitive target cells in a caspase-dependent fashion. We recently found that TRAIL may be constitutively expressed on the surface of mouse and human tumor cells of T and B origin. To define the pattern of TRAIL expression in normal immune cells, freshly isolated splenocytes, Concanavalin A/IL-2-activated T cells and lipopolysaccharide-activated B cells were analyzed by surface staining with or without secondary stimulation. Activated, but not resting, CD3+ cells expressed TRAIL in an activation-dependent fashion. Conversely, freshly isolated B220+ cells displayed surface TRAIL and CD95L that were retained following activation. Restimulation with the protein kinase C activator phorbol 12-myristate 13-acetate and the calcium ionophore ionomycin or an agonistic anti-CD3 monoclonal antibody induced significant up-regulation of surface TRAIL and CD95L in CD3+, TCRalphabeta cells with CD4+ or CD8+ phenotype. Similarly to CD95L, TRAIL up-regulation was protein synthesis dependent and cyclosporin A sensitive. These results indicate that both TRAIL and CD95L are displayed on the cell surface of activated immune cells and may thus represent complementary effector pathways in the regulatory functions of T and B cells.