title: Enhanced apoptotic action of trichosanthin in HIV-1 infected cells.
abstract: Trichosanthin (TCS) is a type 1 ribosome-inactivating protein (RIP) effective against HIV-1 replication. The mechanism is not clear. Present results suggested that the antiviral action may be partly mediated through enhanced apoptosis on infected cells. TCS induced apoptosis in normal H9 cells and this action was more potent in those infected with HIV-1. In flow cytometry study, TCS induced larger population of apoptotic H9 cells chronically infected with HIV-1 in a dose-dependent manner. At TCS concentration of 25 microg/ml, 8.4% of normal H9 cells were found to be apoptotic whereas the same concentration induced 24.5% in HIV-1 chronically infected cells. Such difference was not found in the control experiments without TCS treatment. Two other studies supported this action. Cytotoxic study showed that cell viability was always lower in HIV-1 infected cells after TCS treatment, and DNA fragmentation study confirmed more laddering in infected cells. The mechanism of TCS induced apoptosis in normal or infected H9 cells is not clear. Results in this study demonstrated that TCS is more effective in inducing apoptosis in HIV-1 infected cells. This may explain in part the antiviral action of TCS.
authors.affiliation: Laboratory of Molecular Immunopharmacology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Wang
authors.forename: Dong-Yun
authors.initials: DY
authors.lastname: Ouyang
authors.forename: Hai
authors.initials: H
authors.lastname: Huang
authors.forename: Herman
authors.initials: H
authors.lastname: Chan
authors.forename: Siu-Cheung
authors.initials: SC
authors.lastname: Tam
authors.forename: Yong-Tang
authors.initials: YT
authors.lastname: Zheng
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D005434:Flow Cytometry; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D015978:Trichosanthin / Q000494:pharmacology*
chemical_list: D015978:Trichosanthin