High-level expression of active HIV-1 integrase from a synthetic gene in human cells

A synthetic gene encoding for HIV-1 integase was designed to circumvent the intrinsic instability and the repressor elements present in the wild-type gene. High-level expression of HIV-1 integrase was obtained in various huma n cell lines independently of viral accessory proteins. A human 293T cell l ine was selected that stably expresses HIV-1 integrase and has growth kinet ics comparable to the parental cell line. The enzyme was localized in the n ucleus and remained stably associated with the chromosomes during mitosis. Lentiviral vector particles carrying the inactivating D64V mutation in the integase gene were capable of stably transducing 293T cells when complement ed in the producer cells with integrase expressed from the synthetic gene. When the cell line that stably expresses integase was infected with the def ective viral particles, complementation of integrase activity was detected as well. Expression of active HIV-1 integase in human cells will facilitate the study of the interplay between host and viral factors during integatio n.