title: Antigen-specific T cell responses induced by Towne cytomegalovirus (CMV) vaccine in CMV-seronegative vaccine recipients.
abstract: BACKGROUND
  Towne cytomegalovirus (CMV) vaccine is safe and immunogenic, though its protective efficacy has yet to be optimized.
  
  
  OBJECTIVE
  Describe antigen-specific T cell responses to Towne vaccination.
  
  
  METHODS
  3000 pfu Towne CMV vaccine were given to 12 CMV-seronegative volunteers. CMV-specific CD4+ and CD8+ T cell proliferation and IFNgamma expression were measured by flow cytometry after stimulation with CMV lysate or peptides.
  
  
  RESULTS
  All vaccinees developed CD4+ and CD8+ T cell proliferation and CD4+ T cell IFNgamma responses to multiple CMV antigens, but their CD8+ T cells had low or undetectable IFNgamma responses to pp65 peptide pool. The seven HLA-A2+ subjects had higher CD8+ T cell proliferation and IFNgamma responses to IE than pp65, and two never developed CD8+ T cell IFNgamma responses to pp65. Peak CD4+ T cell IFNgamma responses to CMV lysate were lower than values observed in natural CMV seropositives. Initial CD4+ and CD8+ T cell responses to lysate and pp65 waned after 12 months to levels that were lower than those in healthy CMV seropositives, while vaccinees' CD8+ T cell responses to IE were robust and prolonged.
  
  
  CONCLUSIONS
  Correlating CMV antigen-specific T cell responses with clinical protective efficacy may facilitate future CMV vaccine development.
authors.affiliation: Positive Health Program, Department of Medicine, University of California San Francisco, 4th Floor, 995 Potrero, San Francisco, CA 94110, USA. mjacobson@php.ucsf.edu
authors.forename: Mark A
authors.initials: MA
authors.lastname: Jacobson
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Sinclair
authors.forename: Barry
authors.initials: B
authors.lastname: Bredt
authors.forename: Laurie
authors.initials: L
authors.lastname: Agrillo
authors.forename: Douglas
authors.initials: D
authors.lastname: Black
authors.forename: C Lorrie
authors.initials: CL
authors.lastname: Epling
authors.forename: Alexander
authors.initials: A
authors.lastname: Carvidi
authors.forename: Terence
authors.initials: T
authors.lastname: Ho
authors.forename: Raji
authors.initials: R
authors.lastname: Bains
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Adler
mesh_terms: D000293:Adolescent; D000328:Adult; D000956:Antigens, Viral / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000517:prevention & control; D022482:Cytomegalovirus Vaccines / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010750:Phosphoproteins / Q000276:immunology; D014763:Viral Matrix Proteins / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D022482:Cytomegalovirus Vaccines; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D007371:Interferon-gamma