Kaposi's Sarcoma-Associated Herpesvirus ORF54/dUTPase Downregulates a Ligand for the NK Activating Receptor NKp44

ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV) establishes long-term latent infection in humans and can cause cancers in endothelial and B cells. A functioning immune system is vital for restricting viral proliferation and preventing KSHV-dependent neoplasms. While natural killer (NK) lymphocytes are known to target virus-infected cells for destruction, their importance in the anti-KSHV immune response is not currently understood. Activating receptors on NK cells recognize ligands on target cells, including the uncharacterized ligand(s) for NKp44, termed NKp44L. Here we demonstrate that several NK ligands are affected when KSHV-infected cells are induced to enter the lytic program. We performed a screen of most of the known KSHV genes and found that the product of the ORF54 gene could downregulate NKp44L. The ORF54-encoded protein is a dUTPase; however, dUTPase activity is neither necessary nor sufficient for the downregulation of NKp44L. In addition, we find that ORF54 can also target proteins of the cytokine receptor family and the mechanism of downregulation involves perturbation of membrane protein trafficking. The ORF54-related proteins of other human herpesviruses do not possess this activity, suggesting that the KSHV homolog has evolved a novel immunoregulatory function and that the NKp44-NKp44L signaling pathway contributes to antiviral immunity.

[1]  R. Sun,et al.  The Anti-interferon Activity of Conserved Viral dUTPase ORF54 is Essential for an Effective MHV-68 Infection , 2011, PLoS pathogens.

[2]  D. Ganem,et al.  Generation of a doxycycline-inducible KSHV producer cell line of endothelial origin: maintenance of tight latency with efficient reactivation upon induction. , 2011, Journal of virological methods.

[3]  E. Campbell,et al.  Degranulation of natural killer cells following interaction with HIV-1-infected cells is hindered by downmodulation of NTB-A by Vpu. , 2010, Cell host & microbe.

[4]  A. Moses,et al.  Molecular Mechanism of BST2/Tetherin Downregulation by K5/MIR2 of Kaposi's Sarcoma-Associated Herpesvirus , 2009, Journal of Virology.

[5]  H. Agut,et al.  HIV escape from natural killer cytotoxicity: nef inhibits NKp44L expression on CD4+ T cells , 2009, AIDS.

[6]  G. Carpenter,et al.  Trafficking of receptor tyrosine kinases to the nucleus. , 2009, Experimental cell research.

[7]  Noam Stern-Ginossar,et al.  Diverse herpesvirus microRNAs target the stress-induced immune ligand MICB to escape recognition by natural killer cells. , 2009, Cell host & microbe.

[8]  D. Ganem,et al.  A Kaposi's Sarcoma-Associated Herpesvirus Protein That Forms Inhibitory Complexes with Type I Interferon Receptor Subunits, Jak and STAT Proteins, and Blocks Interferon-Mediated Signal Transduction , 2009, Journal of Virology.

[9]  Mair E. M. Thomas,et al.  Down-regulation of NKG2D and NKp80 ligands by Kaposi's sarcoma-associated herpesvirus K5 protects against NK cell cytotoxicity , 2008, Proceedings of the National Academy of Sciences.

[10]  M. Jarahian,et al.  Expression Analysis of the Ligands for the Natural Killer Cell Receptors NKp30 and NKp44 , 2007, PloS one.

[11]  A. Carbone,et al.  KSHV/HHV8‐associated lymphomas , 2007, British journal of haematology.

[12]  G. Carpenter,et al.  Role of the Sec61 translocon in EGF receptor trafficking to the nucleus and gene expression. , 2007, Molecular biology of the cell.

[13]  H. Šimić,et al.  The herpesviral Fc receptor fcr-1 down-regulates the NKG2D ligands MULT-1 and H60 , 2006, The Journal of experimental medicine.

[14]  D. Cosman,et al.  Down-regulation of the NKG2D ligand MICA by the human cytomegalovirus glycoprotein UL142. , 2006, Biochemical and biophysical research communications.

[15]  Roberta Castriconi,et al.  Surface NK receptors and their ligands on tumor cells. , 2006, Seminars in immunology.

[16]  D. Ganem,et al.  KSHV infection and the pathogenesis of Kaposi's sarcoma. , 2006, Annual review of pathology.

[17]  A. Davison,et al.  New Genes from Old: Redeployment of dUTPase by Herpesviruses , 2005, Journal of Virology.

[18]  H. Ploegh,et al.  Viral modulation of antigen presentation: manipulation of cellular targets in the ER and beyond , 2005, Immunological reviews.

[19]  S. Cusack,et al.  The monomeric dUTPase from Epstein-Barr virus mimics trimeric dUTPases. , 2005, Structure.

[20]  D. Ganem,et al.  RNAs in the Virion of Kaposi's Sarcoma-Associated Herpesvirus , 2005, Journal of Virology.

[21]  P. Tomasec,et al.  Downregulation of natural killer cell–activating ligand CD155 by human cytomegalovirus UL141 , 2005, Nature Immunology.

[22]  L. Lanier,et al.  The Cytomegalovirus m155 Gene Product Subverts Natural Killer Cell Antiviral Protection by Disruption of H60–NKG2D Interactions , 2004, The Journal of experimental medicine.

[23]  M. Wilmanns,et al.  Structural Insights into the Catalytic Mechanism of Phosphate Ester Hydrolysis by dUTPase*♦ , 2004, Journal of Biological Chemistry.

[24]  J. Vieira,et al.  Use of the red fluorescent protein as a marker of Kaposi's sarcoma-associated herpesvirus lytic gene expression. , 2004, Virology.

[25]  P. Caposio,et al.  Evidence that the human cytomegalovirus 46-kDa UL72 protein is not an active dUTPase but a late protein dispensable for replication in fibroblasts. , 2004, Virology.

[26]  B. Chandran,et al.  Concurrent Expression of Latent and a Limited Number of Lytic Genes with Immune Modulation and Antiapoptotic Function by Kaposi's Sarcoma-Associated Herpesvirus Early during Infection of Primary Endothelial and Fibroblast Cells and Subsequent Decline of Lytic Gene Expression , 2004, Journal of Virology.

[27]  D. Ganem,et al.  Lytic KSHV infection inhibits host gene expression by accelerating global mRNA turnover. , 2004, Molecular cell.

[28]  L. Moretta,et al.  Unravelling natural killer cell function: triggering and inhibitory human NK receptors , 2004, The EMBO journal.

[29]  D. Ganem,et al.  Host Range of Kaposi's Sarcoma-Associated Herpesvirus in Cultured Cells , 2003, Journal of Virology.

[30]  L. Lanier,et al.  NKG2D-mediated Natural Killer Cell Protection Against Cytomegalovirus Is Impaired by Viral gp40 Modulation of Retinoic Acid Early Inducible 1 Gene Molecules , 2003, The Journal of experimental medicine.

[31]  D. Ganem,et al.  A novel class of herpesvirus-encoded membrane-bound E3 ubiquitin ligases regulates endocytosis of proteins involved in immune recognition , 2001, The Journal of cell biology.

[32]  K. Makino,et al.  Nuclear localization of EGF receptor and its potential new role as a transcription factor , 2001, Nature Cell Biology.

[33]  W. Fanslow,et al.  ULBP1, 2, 3: novel MHC class I‐related molecules that bind to human cytomegalovirus glycoprotein UL16, activate NK cells , 2001, European journal of immunology.

[34]  R. Armitage,et al.  ULBPs, novel MHC class I-related molecules, bind to CMV glycoprotein UL16 and stimulate NK cytotoxicity through the NKG2D receptor. , 2001, Immunity.

[35]  R. Johnson,et al.  Inhibition of natural killer cell-mediated cytotoxicity by Kaposi's sarcoma-associated herpesvirus K5 protein. , 2000, Immunity.

[36]  D. Ganem,et al.  Kaposi's sarcoma-associated herpesvirus encodes two proteins that block cell surface display of MHC class I chains by enhancing their endocytosis. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[37]  Jae U. Jung,et al.  Downregulation of Major Histocompatibility Complex Class I Molecules by Kaposi's Sarcoma-Associated Herpesvirus K3 and K5 Proteins , 2000, Journal of Virology.

[38]  E. Kremmer,et al.  Kaposi's sarcoma-associated herpesvirus (human herpesvirus-8) ORF54 encodes a functional dUTPase expressed in the lytic replication cycle. , 1999, The Journal of general virology.

[39]  G. Muscat,et al.  Structure/function analysis of a dUTPase: catalytic mechanism of a potential chemotherapeutic target. , 1999, Journal of molecular biology.

[40]  R. Biassoni,et al.  NKp44, A Triggering Receptor Involved in Tumor Cell Lysis by Activated Human Natural Killer Cells, Is a Novel Member of the Immunoglobulin Superfamily , 1999, The Journal of experimental medicine.

[41]  D. Ganem,et al.  Reactivation of Kaposi's sarcoma-associated herpesvirus infection from latency by expression of the ORF 50 transactivator, a homolog of the EBV R protein. , 1998, Virology.

[42]  P. Nyman,et al.  Kinetic properties and stereospecificity of the monomeric dUTPase from herpes simplex virus type 1 , 1998, FEBS letters.

[43]  R. Sun,et al.  A viral gene that activates lytic cycle expression of Kaposi's sarcoma-associated herpesvirus. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[44]  L. Moretta,et al.  NKp44, a Novel Triggering Surface Molecule Specifically Expressed by Activated Natural Killer Cells, Is Involved in Non–Major Histocompatibility Complex–restricted Tumor Cell Lysis , 1998, The Journal of experimental medicine.

[45]  J. Ambroziak,et al.  Herpes-like sequences in HIV-infected and uninfected Kaposi's sarcoma patients. , 1995, Science.

[46]  I. Lehman,et al.  dUTPase from herpes simplex virus type 1; purification from infected green monkey kidney (Vero) cells and from an overproducing Escherichia coli strain. , 1993, Protein expression and purification.

[47]  J. Orange,et al.  Natural killer cells in human health and disease. , 2006, Clinical immunology.

[48]  L. Lanier,et al.  Viral modulation of NK cell immunity , 2005, Nature Reviews Microbiology.