Induction of apoptosis in a macrophage cell line RAW 264.7 by acemannan, a beta-(1,4)-acetylated mannan.
Acemannan is a polydispersed beta-(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 IFNgamma, 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 IFNgamma 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 IFNgamma also inhibited the expression of bcl-2. These results suggest that acemannan in the presence of IFNgamma induces apoptosis in RAW 264.7 cells through a mechanism involving the inhibition of bcl-2 expression.
Ramamoorthy
L
L
Department of Veterinary Pathobiology, Texas A & M University, College Station, Texas 77843, USA. l0r7859@nigel.tamu.edu
Tizard
I R
IR
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D007371:Interferon-gamma / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology; D008351:Mannans / Q000494:pharmacology*; D051379:Mice; D009569:Nitric Oxide / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis
D000998:Antiviral Agents; D008351:Mannans; D019253:Proto-Oncogene Proteins c-bcl-2; D009569:Nitric Oxide; D007371:Interferon-gamma; C058414:acemannan