Generation and validation of a highly sensitive bioluminescent HIV-1 reporter vector that simplifies measurement of virus release

Kirui, James; Freed, Eric O.

BACKGROUND: The continued persistence of HIV-1 as a public health concern due to the lack of a cure calls for the development of new tools for studying replication of the virus. Here, we used NanoLuc, a small and extremely bright luciferase protein, to develop an HIV-1 bioluminescent reporter virus that simplifies functional measurement of virus particle production. RESULTS: The reporter virus encodes a Gag protein containing NanoLuc inserted between the matrix (MA) and capsid (CA) domains of Gag, thereby generating virus particles that package high levels of the NanoLuc reporter. We observe that inserting the NanoLuc protein within HIV-1 Gag has minimal impact on Gag expression and virus particle release. We show that the reporter virus recapitulates inhibition of HIV-1 particle release by Gag mutations, the restriction factor tetherin, and the small-molecule inhibitor amphotericin-B methyl ester. CONCLUSION: These results demonstrate that this vector will provide a simple and rapid tool for functional studies of virus particle assembly and release and high-throughput screening for cellular factors and small molecules that promote or inhibit HIV-1 particle production.