Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2005 Sep;79(18):11580-7.
doi: 10.1128/JVI.79.18.11580-11587.2005.

Differential restriction of human immunodeficiency virus type 2 and simian immunodeficiency virus SIVmac by TRIM5alpha alleles

Laura M J Ylinen  1 , Zuzana Keckesova, Sam J Wilson, Srinika Ranasinghe, Greg J Towers
Affiliations
Comparative Study

Differential restriction of human immunodeficiency virus type 2 and simian immunodeficiency virus SIVmac by TRIM5alpha alleles

Laura M J Ylinen et al. J Virol. 2005 Sep.

Abstract

Primate lentiviruses have narrow host ranges, due in part to their sensitivities to mammalian intracellular antiviral factors such as APOBEC3G and TRIM5alpha. Despite the protection provided by this innate immune system, retroviruses are able to transfer between species where they can cause disease. This is true for sooty mangabey simian immunodeficiency virus, which has transferred to humans as HIV-2 and to rhesus macaques as SIVmac, where it causes AIDS. Here we examine the sensitivities of the closely related HIV-2 and SIVmac to restriction by TRIM5alpha. We show that rhesus TRIM5alpha can restrict HIV-2 but not the closely related SIVmac. SIVmac has not completely escaped TRIM5alpha, as shown by its sensitivity to distantly related TRIM5alpha from the New World squirrel monkey. Squirrel monkey TRIM5alpha blocks SIVmac infection after DNA synthesis and is not saturable with restriction-sensitive virus-like particles. We map the determinant for TRIM5alpha sensitivity to the structure in the capsid protein that recruits CypA into HIV-1 virions. We also make an SIV, mutated at this site, which bypasses restriction in all cells tested.

PubMed Disclaimer

Figures

FIG. 1.
FIG. 1.
Titration of HIV-2 and SIVmac-GFP onto cells from cat, rhesus macaque, squirrel monkey, and human. Threefold serial dilutions of HIV-2 GFP (•) and SIVmac GFP (▴) were titrated onto cells, and GFP expression was measured 48 h later. Virus doses were measured by reverse transcriptase ELISA. Results are representative of three repetitions.
FIG. 2.
FIG. 2.
TRIM5-specific siRNA rescues infectivity of restricted virus in rhesus, squirrel monkey, and human cells. Rhesus macaque FRhK4 cells, squirrel monkey pindak cells, or human TE671 cells were left untreated (striped bars) or were mock treated (open bars) or treated with siRNA to TRIM5 (solid bars). Forty-eight h later, cells were infected with equal doses (determined by RT ELISA) of HIV-2 GFP or SIVmac GFP as shown. Doses were chosen such that the percentages of infected cells were between 0.5 and 2%. Errors are standard errors of the mean of two independent infections by two independent virus preparations. Viral titers, in infectious units per nanogram of reverse transcriptase (Titer i.u./ng RT), were measured by ELISA.
FIG.3.
FIG.3.
Expression of rhesus, squirrel monkey, or human TRIM5α in permissive feline cells renders them nonpermissive for restricted retrovirus. (A) Human (Hu), rhesus (Rh), and squirrel monkey (SM) TRIM5α sequences are aligned. (B) Cat cells were left untransduced as a control or were transduced with retroviral vector encoding rhesus macaque TRIM5α, squirrel monkey TRIM5α, or human TRIM5α, and TRIM5α-positive clones were isolated by limiting dilution. Serial dilutions of HIV-2 GFP (•) or SIVmac GFP (▴) were then titrated onto the TRIM5α-positive cells and the percent infected cells determined by FACS. Viral doses were measured by RT ELISA. Results are representative of three repetitions.
FIG. 4.
FIG. 4.
Restriction by squirrel monkey TRIM5α is after DNA synthesis and is not saturable with restriction-sensitive virus-like particles. (A) Cells from species indicated, i.e., cat CRFK, rhesus FRhK4, squirrel (Sq.) monkey pindak, or cat CRFK expressing squirrel monkey TRIM5α (CRFK PDKT5), were infected with equal doses of SIVmac GFP (open bars) and HIV-2 (solid bars) determined by RT ELISA. Six h postinfection, total DNA was purified and 100 ng subjected to quantitative PCR for the GFP target. This experiment was repeated as described above, except that infections were performed on (B) rhesus macaque FRhK4 cells or (C) squirrel monkey pindak cells, and DNA was purified from parallel samples at the time points indicated. Errors are standard errors of the mean of two independent infections performed in parallel, and data are representative of two repetitions using independent virus preparations. (D) A fixed dose of HIV-2 GFP (filled symbols) or SIVmac GFP (open symbols) was used to infect rhesus macaque FRhK4 cells in the presence or absence of a serial dilution of HIV-1 VLP. SIVmac GFP was used to infect squirrel monkey pindak cells in the presence or absence of a serial dilution of SIVmac VLP. The n-fold increase in viral titer in the presence of the VLP is plotted as a function of VLP dose as measured by RT ELISA. The fixed doses of GFP-encoding viruses were chosen to infect between 0.5 and 2% of the target cells.
FIG. 5.
FIG. 5.
Mutational analysis reveals that TRIM5α sensitivity determinants lie in the capsid region equivalent to the cyclophilin A binding loop of HIV-1. (A) Partial capsid sequences of HIV-1, HIV-2, SIVmac, and SIVmac mutants. CA residue numbers are marked, mutated residues are in bold, and alignment symbols refer to SIVmac and HIV-2. The G-P motif responsible for recruiting CypA into HIV-1 cores is underlined. (B) Titers of SIVmac, HIV-2, SIVmac encoding HIV-2 CA residues 78 to 98 (SIV H2L), and SIVmac containing HIV-2 residues 89 to 91 (SIVmac QQ LPA) were determined on human TE671 cells, rhesus macaque FRhK4 cells, and squirrel monkey pindak cells. Errors are standard errors of the mean from two independent experiments performed with two independent virus prepara-tions. Virus doses to determine titer infected between 1 and 15% of target cells. Also shown are titrations of SIVmac GFP (filled symbols) and SIVmac QQ-LPA (open symbols) on feline CRFK cells. (C) Serial dilutions of wild-type HIV-2 GFP (filled symbols) and HIV-2 G87A (open symbols) GFP were titrated onto human TE671 cells, squirrel monkey pindak cells, feline CRFK cells, and feline CRFK cells expressing squirrel monkey TRIM5. Viral doses were determined by RT ELISA. Plots are representative of two independent experiments performed with two independent viral preparations. Viral titers, in infectious units per nanogram of reverse transcriptase (Titer i.u./ng RT), were measured by ELISA.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Bainbridge, J. W., C. Stephens, K. Parsley, C. Demaison, A. Halfyard, A. J. Thrasher, and R. R. Ali. 2001. In vivo gene transfer to the mouse eye using an HIV-based lentiviral vector; efficient long-term transduction of corneal endothelium and retinal pigment epithelium. Gene. Ther. 8:1665-1668. - PubMed
    1. Besnier, C., Y. Takeuchi, and G. Towers. 2002. Restriction of lentivirus in monkeys. Proc. Natl. Acad. Sci. USA 99:11920-11925. - PMC - PubMed
    1. Bieniasz, P. D. 2004. Intrinsic immunity: a front-line defense against viral attack. Nat. Immunol. 5:1109-1115. - PubMed
    1. Bock, M., K. Bishop, G. Towers, and J. P. Stoye. 2000. Use of a transient assay for studying the genetic determinants of Fv1 restriction. J. Virol. 74:7422-7430. - PMC - PubMed
    1. Braaten, D., E. K. Franke, and J. Luban. 1996. Cyclophilin A is required for the replication of group M human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus SIV(CPZ)GAB but not group O HIV-1 or other primate immunodeficiency viruses. J. Virol. 70:4220-4227. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources

-