TY - JOUR T1 - Induction of Apoptosis in a Macrophage Cell Line RAW 264.7 By Acemannan, a β-(1,4)-Acetylated Mannan JF - Molecular Pharmacology JO - Mol Pharmacol SP - 415 LP - 421 DO - 10.1124/mol.53.3.415 VL - 53 IS - 3 AU - Lalitha Ramamoorthy AU - Ian R. Tizard Y1 - 1998/03/01 UR - http://molpharm.aspetjournals.org/content/53/3/415.abstract N2 - Acemannan is a polydispersed β-(1,4)-linked acetylated mannan with antiviral properties. It is an immunomodulator, and studies in our laboratory have shown that it causes activation of macrophages. In the presence of IFNγ, acemannan induced apoptosis in RAW 264.7 cells. These cells exhibited chromatin condensation, DNA fragmentation, and laddering characteristic of apoptosis. The induction of apoptosis by acemannan and IFNγ does not seem to be mediated by nitric oxide, since N-nitro-l-arginine methyl ester, the nitric oxide inhibitor, had no effect. Acemannan in the presence of IFNγ also inhibited the expression of bcl-2. These results suggest that acemannan in the presence of IFNγ induces apoptosis in RAW 264.7 cells through a mechanism involving the inhibition ofbcl-2 expression. ER -