Effects of vpu start-codon mutations on human immunodeficiency virus type 1 replication in macrophages
Graduate School of Biomedical Sciences; Program in Molecular Medicine
Life Sciences | Medicine and Health Sciences
The human immunodeficiency virus type 1 (HIV-1) vpu protein increases the release of virus particles from infected cells. Mutations that abrogate vpu function have a profound effect on HIV-1 replication in primary macrophage cultures. About 1.24 % of primary isolates in the HIV databases have vpu start-codon mutations. In addition, the envelope of the AD8 isolate was reported to compensate for the lack of vpu, whilst the YU-2 virus (cloned directly from the brain tissue of an infected individual) is macrophage-tropic, despite having a vpu start-codon mutation. These observations raise the possibility that envelopes evolve to compensate for the loss of vpu function in vivo. Chimeric vpu+ and vpu- replication-competent clones were constructed that contained the envelopes of SF162, AD8 or YU-2. Macrophages were infected with these chimeras and virus release was measured over time by a reverse transcriptase ELISA. It was found that vpu-deficient chimeras carrying AD8 and YU-2 envelopes were consistently released at lower levels than their wild-type (wt) vpu counterparts, indicating that these envelopes did not compensate for the lack of vpu. Non-chimeric vpu+ and vpu- AD8 and YU-2 followed similar patterns, although replication by vpu-deficient AD8 was variable, with virion release reaching 60 % of that recorded for AD8 with a wt vpu. In summary, no evidence was found that the AD8 or YU-2 envelopes can compensate for the lack of vpu for replication in macrophages.
DOI of Published Version
J Gen Virol. 2007 Oct;88(Pt 10):2780-92. Link to article on publisher's site
The Journal of general virology
Richards KH, Clapham PR. (2007). Effects of vpu start-codon mutations on human immunodeficiency virus type 1 replication in macrophages. Morningside Graduate School of Biomedical Sciences Student Publications. https://doi.org/10.1099/vir.0.83120-0. Retrieved from https://escholarship.umassmed.edu/gsbs_sp/373