Somatic cell genetic analyses to identify HIV-1 host restriction factors

Cellular proteins are critically involved in all steps of the human immunodeficiency virus type 1 HIV-1) life cycle. Disruption of host functions essential for virus replication or discovery of new proteins that block viral replication may provide novel antiviral approaches. In recent years, genetic selections for and against genes carried by retroviral vectors have become increasingly powerful, allowing for the isolation of cells with altered susceptibility to virus infection. Screening complementary DNA libraries for clones able to induce resistance to infection by recombinant HIV-1 genomes, has proved to be an excellent tool to identify new interfering factors. The restriction factors TRIM5alpha1, the Zinc Finger Antiviral Protein ZAP) 2 as well as the dominant negative factor N-86-HnRNPU 3 have all been discovered by means of such genetic screens. Here we report the strategy and techniques to prepare a library and isolate HIV antiviral genes, using the identification of N-86-HnRNPU as an example.