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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 is more likely to induce surface expression of ULBP-1 and ULBP-2 than ULBP-3, MIC-A or MIC-B on infected cells.Primary CD4pos T-cell blasts were infected with wild-type (WT) HIV-1. As a control, the same cells were infected with HIV-1 that was deficient in expression of Vpr (ΔVpr). As an additional control we evaluated uninfected CD4pos T-cells for expression of individual NKG2D ligands (blue lines). Following infection, cells were surface stained using fluorochrome-conjugated mAb specific for: CD4 (A-J), ULBP-1 (A–B), ULBP-2 (C–D), ULBP-3 (E–F), MIC-A (G–H) or MIC-B (I–J). The cells were then intracellularly stained for HIV-1 p24 antigen. Histograms were derived following acquisition of 104 viable uninfected CD4pos cells (blue line) or 104 viable CD4neg and HIV-1 p24 Agpos infected cells (red line). Green line represents the histogram of staining controls (isotype controls). The figure is representative data from two separate experiments.
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ppat-1000613-g004: Vpr is more likely to induce surface expression of ULBP-1 and ULBP-2 than ULBP-3, MIC-A or MIC-B on infected cells.Primary CD4pos T-cell blasts were infected with wild-type (WT) HIV-1. As a control, the same cells were infected with HIV-1 that was deficient in expression of Vpr (ΔVpr). As an additional control we evaluated uninfected CD4pos T-cells for expression of individual NKG2D ligands (blue lines). Following infection, cells were surface stained using fluorochrome-conjugated mAb specific for: CD4 (A-J), ULBP-1 (A–B), ULBP-2 (C–D), ULBP-3 (E–F), MIC-A (G–H) or MIC-B (I–J). The cells were then intracellularly stained for HIV-1 p24 antigen. Histograms were derived following acquisition of 104 viable uninfected CD4pos cells (blue line) or 104 viable CD4neg and HIV-1 p24 Agpos infected cells (red line). Green line represents the histogram of staining controls (isotype controls). The figure is representative data from two separate experiments.

Mentions: The studies illustrated in Figures 1–3 utilized a soluble NKG2D construct that is unable to distinguish between the various ligands. Hence, we wished to determine which of the NKG2D ligands were specifically induced by Vpr. For this purpose, we compared the expression of ULBP-1, ULBP-2, ULBP-3, MIC-A and MIC-B on DHIV-infected cells. In the studies shown in Figure 4, we demonstrate that WT virus induced ULBP-1 (Figure 4A; MFI = 483 for WT virus-infected cells compared with MFI = 167 for uninfected cells) and ULBP-2 (Figure 4C; MFI = 539 for WT virus-infected cells compared with MFI = 131 for uninfected cells). In contrast, little or no induction of ULBP-3 (Figure 4E; MFI = 150 for WT virus-infected cells compared with MFI = 134 for uninfected cells), MIC-A (Figure 4G; MFI = 187 for WT virus-infected cells compared with MFI = 106 for uninfected cells) or MIC-B (Figure 4I; MFI = 99.8 for WT virus-infected cells compared with MFI = 90.5 for uninfected cells) was detected.


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 is more likely to induce surface expression of ULBP-1 and ULBP-2 than ULBP-3, MIC-A or MIC-B on infected cells.Primary CD4pos T-cell blasts were infected with wild-type (WT) HIV-1. As a control, the same cells were infected with HIV-1 that was deficient in expression of Vpr (ΔVpr). As an additional control we evaluated uninfected CD4pos T-cells for expression of individual NKG2D ligands (blue lines). Following infection, cells were surface stained using fluorochrome-conjugated mAb specific for: CD4 (A-J), ULBP-1 (A–B), ULBP-2 (C–D), ULBP-3 (E–F), MIC-A (G–H) or MIC-B (I–J). The cells were then intracellularly stained for HIV-1 p24 antigen. Histograms were derived following acquisition of 104 viable uninfected CD4pos cells (blue line) or 104 viable CD4neg and HIV-1 p24 Agpos infected cells (red line). Green line represents the histogram of staining controls (isotype controls). The figure is representative data from two separate experiments.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2747015&req=5

ppat-1000613-g004: Vpr is more likely to induce surface expression of ULBP-1 and ULBP-2 than ULBP-3, MIC-A or MIC-B on infected cells.Primary CD4pos T-cell blasts were infected with wild-type (WT) HIV-1. As a control, the same cells were infected with HIV-1 that was deficient in expression of Vpr (ΔVpr). As an additional control we evaluated uninfected CD4pos T-cells for expression of individual NKG2D ligands (blue lines). Following infection, cells were surface stained using fluorochrome-conjugated mAb specific for: CD4 (A-J), ULBP-1 (A–B), ULBP-2 (C–D), ULBP-3 (E–F), MIC-A (G–H) or MIC-B (I–J). The cells were then intracellularly stained for HIV-1 p24 antigen. Histograms were derived following acquisition of 104 viable uninfected CD4pos cells (blue line) or 104 viable CD4neg and HIV-1 p24 Agpos infected cells (red line). Green line represents the histogram of staining controls (isotype controls). The figure is representative data from two separate experiments.
Mentions: The studies illustrated in Figures 1–3 utilized a soluble NKG2D construct that is unable to distinguish between the various ligands. Hence, we wished to determine which of the NKG2D ligands were specifically induced by Vpr. For this purpose, we compared the expression of ULBP-1, ULBP-2, ULBP-3, MIC-A and MIC-B on DHIV-infected cells. In the studies shown in Figure 4, we demonstrate that WT virus induced ULBP-1 (Figure 4A; MFI = 483 for WT virus-infected cells compared with MFI = 167 for uninfected cells) and ULBP-2 (Figure 4C; MFI = 539 for WT virus-infected cells compared with MFI = 131 for uninfected cells). In contrast, little or no induction of ULBP-3 (Figure 4E; MFI = 150 for WT virus-infected cells compared with MFI = 134 for uninfected cells), MIC-A (Figure 4G; MFI = 187 for WT virus-infected cells compared with MFI = 106 for uninfected cells) or MIC-B (Figure 4I; MFI = 99.8 for WT virus-infected cells compared with MFI = 90.5 for uninfected cells) was detected.

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