SERGERIE Y, BOIVIN G; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. V-283.

CHUQ-CHUL (Laval University), Quebec, PQ, Canada.

BACKGROUND: HHV-8, the etiologic agent of Kaposi's sarcoma, poorly replicates in most cell lines. Some authors have evaluated drug susceptibility profiles for HHV-8 although the methods used were cumbersome and only one infected cell line was evaluated. Here, we report on a new in vitro system based on real-time PCR for evaluation of HHV-8 susceptibility to antiviral agents. Such assay was then evaluated using two different cell lines latently infected by HHV-8. METHODS: The primary effusion lymphoma cell lines JSC-1 and BCBL-1 (harboring episomal HHV-8 latent genomes) were exposed to serial antiviral concentrations and induced to lytic replication using 20 ng/ml of TPA. Supernatant viral DNA was quantified by real-time PCR in a LightCycler instrument and compared to a TPA-induced control without drug. The antiviral concentration that reduces viral DNA synthesis by 50% (IC[50)] was determined for each drug in the two cell lines. RESULTS: In both cell lines, cidofovir had the greatest inhibitory activity against HHV-8 (IC[50]: 0.43 micro-M/BCBL-1 and 0.14 micro-M/JSC-1) followed by ganciclovir (IC[50]: 2.61 micro-M/BCBL-1 and 3.54 micro-M/JSC-1). Intermediate concentrations of adefovir (IC[50]: 18.00 micro-M/BCBL-1 and 6.00 micro-M/JSC-1) and foscarnet (IC[50]: 34.15 micro-M/BCBL-1 and 26.00 micro-M/JSC-1) were required to block HHV-8 DNA replication by 50%. JSC-1 derived HHV-8 was ten-fold more sensitive to acyclovir (IC[50]: 3.34 micro-M) than BCBL-1 derived HHV-8 (IC[50]: 31.00 micro-M). Considering achievable serum drug concentrations, the therapeutic ratio (peak serum concentration/drug IC[50)] using the BCBL-1 cell line was highest for cidofovir (167) followed by foscarnet (22), ganciclovir (12), acyclovir (3), and adefovir (0.004). CONCLUSIONS: Our new rapid susceptibility method confirmed the excellent in vitro activity of cidofovir against two HHV-8 isolates. Furthermore, we showed that acyclovir IC[50] values could vary considerably possibly due to viral and/or cellular factors.

Publication Types:

• Meeting Abstracts

Keywords:

• Acyclovir
• Adenine
• Antiviral Agents
• Cell Line
• Cytosine
• DNA, Viral
• Disease Susceptibility
• Foscarnet
• Ganciclovir
• Herpesvirus 8, Human
• Humans
• In Vitro
• Phosphonic Acids
• Polymerase Chain Reaction
• Sarcoma, Kaposi
• adefovir
• cidofovir
• methods

Other ID:

• GWAIDS0024979

UI: 102264603

From Meeting Abstracts