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HIV-1 Vpr triggers natural killer cell-mediated lysis of infected cells through activation of the ATR-mediated DNA damage response.

Ward J, Davis Z, DeHart J, Zimmerman E, Bosque A, Brunetta E, Mavilio D, Planelles V, Barker E - PLoS Pathog. (2009)

Bottom Line: The presence of ULBP-1 and ULBP-2 on HIV-1 infected cells is dependent on the ability of Vpr to associate with a protein complex know as Cullin 4a (Cul4a)/damaged DNA binding protein 1 (DDB1) and Cul4a-associated factor-1(DCAF-1) E3 ubiquitin ligase (Cul4a(DCAF-1)).When T-cell blasts are infected with a vpr-deficient HIV-1, NK cells are impaired in killing the infected cells.Thus, HIV-1 Vpr actively triggers the expression of the ligands to the NK cell activation receptor.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, State University of New York, Upstate Medical University, Syracuse, New York, United States of America.

ABSTRACT
Natural killer (NK) cells are stimulated by ligands on virus-infected cells. We have recently demonstrated that NK cells respond to human immunodeficiency virus type-1 (HIV-1)-infected autologous T-cells, in part, through the recognition of ligands for the NK cell activating receptor NKG2D on the surface of the infected cells. Uninfected primary CD4(pos) T-cell blasts express little, if any, NKG2D ligands. In the present study we determined the mechanism through which ligands for NKG2D are induced on HIV-1-infected cells. Our studies reveal that expression of vpr is necessary and sufficient to elicit the expression of NKG2D ligands in the context of HIV-1 infection. Vpr specifically induces surface expression of the unique-long 16 binding proteins (ULBP)-1 and ULBP-2, but not ULBP-3, MHC class I-related chain molecules (MIC)-A or MIC-B. In these studies we also demonstrated that Vpr increases the level of ULBP-1 and ULBP-2 mRNA in primary CD4(pos) T-cell blasts. The presence of ULBP-1 and ULBP-2 on HIV-1 infected cells is dependent on the ability of Vpr to associate with a protein complex know as Cullin 4a (Cul4a)/damaged DNA binding protein 1 (DDB1) and Cul4a-associated factor-1(DCAF-1) E3 ubiquitin ligase (Cul4a(DCAF-1)). ULBP-1 and -2 expression by Vpr is also dependent on activation of the DNA damage sensor, ataxia telangiectasia and rad-3-related kinase (ATR). When T-cell blasts are infected with a vpr-deficient HIV-1, NK cells are impaired in killing the infected cells. Thus, HIV-1 Vpr actively triggers the expression of the ligands to the NK cell activation receptor.

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Vpr alone is capable of inducing NKG2D ligands surface expression.Primary CD4pos T-cell blasts were transduced with a lentivirus vector (pPR-Vip) coexpressing Vpr and GFP (red line). As a control the same cells were infected with a lentivirus vector expressing GFP only (green line). Following transduction cells were stained with a fusion protein of human NKG2D and the Fc portion of human IgG1 along with fluorochrome-conjugated goat anti-human IgG1. Histograms were derived following acquisition on a flow cytometer of either 104 viable cells [(for untransduced cells) blue line] or 104 viable GFPpos cells (green and red line). The figure is representative data from two separate experiments.
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ppat-1000613-g003: Vpr alone is capable of inducing NKG2D ligands surface expression.Primary CD4pos T-cell blasts were transduced with a lentivirus vector (pPR-Vip) coexpressing Vpr and GFP (red line). As a control the same cells were infected with a lentivirus vector expressing GFP only (green line). Following transduction cells were stained with a fusion protein of human NKG2D and the Fc portion of human IgG1 along with fluorochrome-conjugated goat anti-human IgG1. Histograms were derived following acquisition on a flow cytometer of either 104 viable cells [(for untransduced cells) blue line] or 104 viable GFPpos cells (green and red line). The figure is representative data from two separate experiments.

Mentions: To determine whether Vpr expression is sufficient to induce NKG2D ligands, we resorted to a lentiviral vector that encodes HIV-1 Vpr and GFP but no other viral gene (pPR-VIP). As a control, we used a similar lentiviral vector encoding only GFP. We observed that Vpr alone, but not the control lentiviral vector, was able to induce NKG2D ligands on CD4pos T-cells (Figure 3). Therefore, Vpr is sufficient for HIV-1 to induce NKG2D ligands on the infected cell surface.


HIV-1 Vpr triggers natural killer cell-mediated lysis of infected cells through activation of the ATR-mediated DNA damage response.

Ward J, Davis Z, DeHart J, Zimmerman E, Bosque A, Brunetta E, Mavilio D, Planelles V, Barker E - PLoS Pathog. (2009)

Vpr alone is capable of inducing NKG2D ligands surface expression.Primary CD4pos T-cell blasts were transduced with a lentivirus vector (pPR-Vip) coexpressing Vpr and GFP (red line). As a control the same cells were infected with a lentivirus vector expressing GFP only (green line). Following transduction cells were stained with a fusion protein of human NKG2D and the Fc portion of human IgG1 along with fluorochrome-conjugated goat anti-human IgG1. Histograms were derived following acquisition on a flow cytometer of either 104 viable cells [(for untransduced cells) blue line] or 104 viable GFPpos cells (green and red line). The figure is representative data from two separate experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2747015&req=5

ppat-1000613-g003: Vpr alone is capable of inducing NKG2D ligands surface expression.Primary CD4pos T-cell blasts were transduced with a lentivirus vector (pPR-Vip) coexpressing Vpr and GFP (red line). As a control the same cells were infected with a lentivirus vector expressing GFP only (green line). Following transduction cells were stained with a fusion protein of human NKG2D and the Fc portion of human IgG1 along with fluorochrome-conjugated goat anti-human IgG1. Histograms were derived following acquisition on a flow cytometer of either 104 viable cells [(for untransduced cells) blue line] or 104 viable GFPpos cells (green and red line). The figure is representative data from two separate experiments.
Mentions: To determine whether Vpr expression is sufficient to induce NKG2D ligands, we resorted to a lentiviral vector that encodes HIV-1 Vpr and GFP but no other viral gene (pPR-VIP). As a control, we used a similar lentiviral vector encoding only GFP. We observed that Vpr alone, but not the control lentiviral vector, was able to induce NKG2D ligands on CD4pos T-cells (Figure 3). Therefore, Vpr is sufficient for HIV-1 to induce NKG2D ligands on the infected cell surface.

Bottom Line: The presence of ULBP-1 and ULBP-2 on HIV-1 infected cells is dependent on the ability of Vpr to associate with a protein complex know as Cullin 4a (Cul4a)/damaged DNA binding protein 1 (DDB1) and Cul4a-associated factor-1(DCAF-1) E3 ubiquitin ligase (Cul4a(DCAF-1)).When T-cell blasts are infected with a vpr-deficient HIV-1, NK cells are impaired in killing the infected cells.Thus, HIV-1 Vpr actively triggers the expression of the ligands to the NK cell activation receptor.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, State University of New York, Upstate Medical University, Syracuse, New York, United States of America.

ABSTRACT
Natural killer (NK) cells are stimulated by ligands on virus-infected cells. We have recently demonstrated that NK cells respond to human immunodeficiency virus type-1 (HIV-1)-infected autologous T-cells, in part, through the recognition of ligands for the NK cell activating receptor NKG2D on the surface of the infected cells. Uninfected primary CD4(pos) T-cell blasts express little, if any, NKG2D ligands. In the present study we determined the mechanism through which ligands for NKG2D are induced on HIV-1-infected cells. Our studies reveal that expression of vpr is necessary and sufficient to elicit the expression of NKG2D ligands in the context of HIV-1 infection. Vpr specifically induces surface expression of the unique-long 16 binding proteins (ULBP)-1 and ULBP-2, but not ULBP-3, MHC class I-related chain molecules (MIC)-A or MIC-B. In these studies we also demonstrated that Vpr increases the level of ULBP-1 and ULBP-2 mRNA in primary CD4(pos) T-cell blasts. The presence of ULBP-1 and ULBP-2 on HIV-1 infected cells is dependent on the ability of Vpr to associate with a protein complex know as Cullin 4a (Cul4a)/damaged DNA binding protein 1 (DDB1) and Cul4a-associated factor-1(DCAF-1) E3 ubiquitin ligase (Cul4a(DCAF-1)). ULBP-1 and -2 expression by Vpr is also dependent on activation of the DNA damage sensor, ataxia telangiectasia and rad-3-related kinase (ATR). When T-cell blasts are infected with a vpr-deficient HIV-1, NK cells are impaired in killing the infected cells. Thus, HIV-1 Vpr actively triggers the expression of the ligands to the NK cell activation receptor.

Show MeSH
Related in: MedlinePlus