Highly purified human immunodeficiency virus type 1 reveals a virtual absence of Vif in virions

Markus Dettenhofer, Xiao Fang Yu

Research output: Contribution to journalArticle


The vif gene of human immunodeficiency virus type 1 (HIV-1) is essential for the productive infection of primary blood-derived lymphocytes, macrophages, and certain human T-cell lines. It has been shown that Vif is associated with HIV-1 virions purified by sucrose density-equilibrium gradient analysis. However, the specificity of Vif incorporation into virions has not been determined. Moreover, recent studies have demonstrated that standard HIV-1 particle preparations created with sucrose density-equilibrium gradients are contaminated with cell-derived microvesicles. Here we demonstrate, as previously reported, that Vif cosediments with HIV-1 particles in sucrose density-equilibrium gradient analysis. However, we also found that, when Vif was expressed in the absence of all other HIV-l-encoded gene products and then isolated by sucrose density-equilibrium gradient centrifugation from extracellular supernatants, its sedimentation pattern was largely unaltered, suggesting that Vif can be secreted from cells. Using a newly developed OptiPrep velocity gradient method, we were able to physically separate most of the extracellular Vif from the HIV-1 virions without disrupting the infectivity of the virus. By titrating serial dilutions of purified Vif and Gag against the viral peak fraction in the OptiPrep gradient, we demonstrate that

Original languageEnglish (US)
Pages (from-to)1460-1467
Number of pages8
JournalJournal of Virology
Issue number2
Publication statusPublished - 1999


ASJC Scopus subject areas

  • Immunology

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