Zinc finger nucleases (ZFNs) that cleave HIV pol were developed as antiviral agents.
ZFNs could inhibit production of HIV virions and infectious HIV in vitro.
An infectious and ZFN-resistant HIV provirus was identified in treated cells.
ZFN-resistance HIV remained susceptible to NRTi and NNRTi drugs.
Secondary mutations rendered the ZFN-resistance virus replication incompetent.