title: Dissecting the mode of action of various HIV-inhibitor classes in a stable cellular system.
abstract: We describe a stable and sensitive HIV evaluation system, which discriminates HIV-specific membrane fusion and early transcription events and is suitable for high-throughput inhibitor screening. A human lymphocytic line, constitutively producing infectious HIV-1, serves as Env-positive donor. A second indicator cell line carries a silent HIV-1 LTR lacZ reporter plasmid. A bicellular cocultivation setup allows titration and standardization of "fusion-induced gene stimulation (FIGS)" events. With few manipulations aspects of fusion and/or LTR induction can be distinguished and simultaneously assayed. Anti-Env-V3 antibodies prevent fusion and subsequent lacZ induction, and a Tat-specific inhibitor blocks only lacZ induction in a dose dependent manner without affecting membrane fusion. The LTR reporter is readily activated by Tat from HIV-1, HIV-2, or SIV and it responds to exogenous Tat protein. The reporter system is sensitive enough to detect single infection events on pre-seeded layers of indicator cells, which renders it potentially useful for direct virus quantification in patients' material. Moreover, our system allows to control and normalize DNA transfection efficiencies of HIV-derived plasmids. This aspect is particularly valuable for studies of RT- and protease-inhibitors and resistances, where p24 or supernatant reverse transcriptase, otherwise standard virus readouts, can be directly affected by inhibitors or mutations.
authors.affiliation: Novartis Pharma, Inc., Basel, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Klimkait
authors.forename: F
authors.initials: F
authors.lastname: Stauffer
authors.forename: E
authors.initials: E
authors.lastname: Lupo
authors.forename: C
authors.initials: C
authors.lastname: Sonderegger-Rubli
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D002460:Cell Line; D018920:Coculture Techniques; D004352:Drug Resistance, Microbial; D017930:Genes, Reporter; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D015498:HIV-2 / Q000187:drug effects / Q000254:growth & development; D006367:HeLa Cells; D006801:Humans; D015302:Simian Immunodeficiency Virus / Q000187:drug effects / Q000254:growth & development; D014162:Transfection; D014775:Virus Activation
chemical_list: D019380:Anti-HIV Agents