title: Design and analysis of rhesus cytomegalovirus IL-10 mutants as a model for novel vaccines against human cytomegalovirus.
abstract: BACKGROUND
  Human cytomegalovirus (HCMV) expresses a viral ortholog (CMVIL-10) of human cellular interleukin-10 (cIL-10). Despite only ∼26% amino acid sequence identity, CMVIL-10 exhibits comparable immunosuppressive activity with cIL-10, attenuates HCMV antiviral immune responses, and contributes to lifelong persistence within infected hosts. The low sequence identity between CMVIL-10 and cIL-10 suggests vaccination with CMVIL-10 may generate antibodies that specifically neutralize CMVIL-10 biological activity, but not the cellular cytokine, cIL-10. However, immunization with functional CMVIL-10 might be detrimental to the host because of its immunosuppressive properties.
  
  
  RESULTS
  Structural biology was used to engineer biologically inactive mutants of CMVIL-10 that would, upon vaccination, elicit a potent immune response to the wild-type viral cytokine. To test the designed proteins, the mutations were incorporated into the rhesus cytomegalovirus (RhCMV) ortholog of CMVIL-10 (RhCMVIL-10) and used to vaccinate RhCMV-infected rhesus macaques. Immunization with the inactive RhCMVIL-10 mutants stimulated antibodies against wild-type RhCMVIL-10 that neutralized its biological activity, but did not cross-react with rhesus cellular IL-10.
  
  
  CONCLUSIONS
  This study demonstrates an immunization strategy to neutralize RhCMVIL-10 biological activity using non-functional RhCMVIL-10 antigens. The results provide the methodology for targeting CMVIL-10 in vaccine, and therapeutic strategies, to nullify HCMV's ability to (1) skew innate and adaptive immunity, (2) disseminate from the site of primary mucosal infection, and (3) establish a lifelong persistent infection.
authors: Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors: Naomi J
authors: NJ
authors: Logsdon
authors: Meghan K
authors: MK
authors: Eberhardt
authors: Christopher E
authors: CE
authors: Allen
authors: Peter A
authors: PA
authors: Barry
authors: Mark R
authors: MR
authors: Walter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D049109:Cell Proliferation; D003429:Cross Reactions / Q000276:immunology; D003587:Cytomegalovirus / Q000276:immunology*; D022482:Cytomegalovirus Vaccines / Q000276:immunology*; D015195:Drug Design; D006801:Humans; D007114:Immunization; D016753:Interleukin-10 / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D053709:Interleukin-10 Receptor alpha Subunit / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008253:Macaca mulatta / Q000097:blood / Q000276:immunology*; D018448:Models, Immunological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D017354:Point Mutation / Q000235:genetics; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D020349:Surface Plasmon Resonance
chemical_list: D057134:Antibodies, Neutralizing; D022482:Cytomegalovirus Vaccines; D053709:Interleukin-10 Receptor alpha Subunit; D050505:Mutant Proteins; D016753:Interleukin-10; D018664:Interleukin-12