Li Y, Zhang T, Douglas SD, Ho WZ; Conference on Retroviruses and Opportunistic Infections.

Abstr 10th Conf Retrovir Oppor Infect Feb 10 14 2003 Hynes Conv Cent Boston Mass USA Conf Retrovir Oppor Infect 10th 2003 Boston Mass. 2003 Feb 10-14; 10: abstract no. 158.

Children's Hosp of Philadelphia, Univ of Pennsylvania Sch of Med, PA

BACKGROUND: Although injection drug users (IDUs) are the single largest risk factor for Hepatitis C Virus (HCV) transmission, there is little information available regarding whether substance abuse enhances HCV replication and promotes HCV disease progression. Therefore, we investigated whether morphine alters HCV mRNA expression in a HCV replicon-containing cell clone (Huh.8) that derived from human hepatoma cells (Huh7).METHODS: RT-PCR and Western blotting were used to determine the expression of mu-opioid receptor at mRNA and protein levels, respectively. HCV RNA copy numbers in the Huh.8 cells were quantified by real-time RT-PCR. pNF-kappaB-Luc, a plasmid containing NF-kappaB promoter linked with a luciferase gene, was transfected into Huh7 cells to study the effect of morphine on the NF-kappaB activity. CD8+ T lymphocytes were purified from PBMC isolated from whole blood of HCV-infected adult subjects using MACS CD8 Microbeads.RESULTS: Both Huh.8 and Huh7 cells express mu-opioid receptor. The addition of morphine to the Huh.8 cell cultures resulted in significant increase of HCV mRNA expression. Morphine diminished the anti-HCV effect of IFN-alpha in Huh.8 cells. This stimulatory effect of morphine on HCV mRNA expression was abolished by naltrexone (an opioid receptor antagonist) or beta-funaltrexamine (a specific mu-opioid receptor antagonist). Investigation of the mechanisms responsible for morphine action revealed that morphine activated NF-kappaB promoter and caffeic acid phenethyl ester (CAPE), a potent and specific inhibitor of activation of NF-kappaB, abolished morphine-activated HCV RNA expression in Huh.8 cells. In addition, culture supernatants from the activated CD8+ T-lymphocytes isolated from HCV-infected adult subjects, when added to Huh.8 cell cultures, significantly inhibited HCV RNA expression. This CD8+ T-cell-mediated anti-HCV effect was partially reversed by the addition of morphine to Huh.8 cell cultures.CONCLUSIONS: Our data indicate that morphine may play an important role as a positive regulator of HCV replication in human liver cells in vivo. This enhancing effect of morphine on HCV RNA expression may compromise IFN-alpha therapy as well as CD8+ T-cell-mediated immunity against HCV infection.

Publication Types:

• Meeting Abstracts

Keywords:

• Adult
• Carcinoma, Hepatocellular
• Gene Expression
• Hepacivirus
• Hepatocytes
• Humans
• Interferon-alpha
• Morphine
• NF-kappa B
• Naltrexone
• Narcotic Antagonists
• Promoter Regions (Genetics)
• RNA, Messenger
• Receptors, Opioid, mu
• Replicon
• Transcription Factor RelA
• Transcription, Genetic
• beta-funaltrexamine
• genetics

Other ID:

• GWAIDS0021108

UI: 102260194

From Meeting Abstracts