728 AIDS RESEARCH AND HUMAN RETROVIRUSES Volume 21, Number 8, 2005, pp. 728–733 © Mary Ann Liebert, Inc. Sequence Note Evidence for Host-Driven Selection of the HIV Type 1 vpr Gene in Vivo during HIV Disease Progression in a Transfusion-Acquired Cohort LEON CALI, 1 BIN WANG, 2 MERIET MIKHAIL, 2 MICHAEL J. GILL, 3 BRENDA BECKTHOLD, 3 MARCO SALEMI, 4 DAVID A. JANS, 1 SABINE C. PILLER, 5 and NITIN K. SAKSENA 2 ABSTRACT An epidemiologically linked HIV-1-infected cohort, in which a nonprogressor donor infected two recipients who progressed to AIDS, was examined. Sequence analysis, over time, of HIV-1 vpr gene quasispecies from uncultured peripheral blood cells revealed an insertion of arginine at position 90 altering a highly conserved C-terminal motif, believed to play a role in Vpr nuclear targeting. Full genome analysis from each patient showed no gene defects in other gene regions, implying that the mutational selection was unique to the vpr gene. A detailed analysis of the vpr quasispecies showed very little amino acid diversity in the nonprogress- ing donor, whereas, following viral transmission, the amino acid diversity increased dramatically over time in tandem with disease progression in the two recipients. Although the R insertion at position 90 was present in all three individuals, the variable degree of additional amino acid changes over time may have influenced HIV disease in the nonprogressor donor and the two progressing recipients. These data provide the first ev- idence in favor of vpr gene evolution over time, which was host-driven. The status of the nonprogressing donor was consistent with a highly protective B-57 HLA type, which was absent in the two progressing recipients, implying a role for host HLA type and other immunologic selective pressures in vpr gene selection in vivo. INTRODUCTION T HE HUMAN IMMUNODEFICIENCY VIRUS TYPE-1 (HIV-1) ac- cessory gene product-viral protein R (Vpr) is primarily lo- calized in the nucleus of infected cells. It is incorporated into the virion, consistent with its role during infection 1,2 in impor- tation of the viral preintegration complex into the nucleus of nondividing cells. 3 Vpr also appears to have the ability to en- hance viral replication in macrophages, 4 and most remarkably is able to prevent T cell proliferation by causing them to accu- mulate in the G 2 /M phase of the cell cycle. 5–7 Although the vpr gene is known to increase the rate of viral replication and ac- celerate the cytopathic effect of HIV-1 in T cell lines, growing evidence suggests vpr participation in productive macrophage infection. 8 Recently, mutated Vpr has been implicated in read- ily establishing long-term chronic infection of T cells, whereas normal Vpr is known to increase the rate of viral replication and cytopathic effects of the virus in cell culture. 7 We showed previously that the asymptomatic survival of a chronically infected mother–child pair was due to vpr gene de- fects at the C-terminus, 9 which were seen in 71% of vpr gene clones screened from both plasma and peripheral blood 1 Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Monash, VIC 3800, Australia. 2 Retroviral Genetics Laboratory, Centre for Virus Research, Westmead Millennium Institutes, Westmead Hospital, Westmead NSW 2145, Sydney, Australia. 3 Department of Medicine, University of Calgary, Calgary, Alberta Canada T2N 4N1. 4 College of Medicine, University of Florida, Gainesville, Florida 32610. 5 HIV Protein Functions and Interactions Group, Centre for Virus Research, Westmead Millennium Institutes, Westmead Hospital, Westmead NSW 2145, Sydney, Australia.