title: CMV pp65 and IE-1 T cell epitopes recognized by healthy subjects.
abstract: BACKGROUND
  Adoptive immune and vaccine therapies have been used to prevent cytomegalovirus (CMV) disease in recipients of hematopoietic progenitor cell transplants, but the nature of T cell responses to CMV have not been completely characterized.
  
  
  METHODS
  Peptide pools and individual peptides derived from the immune-dominant CMV proteins pp65 and IE-1 and antigen-specific, cytokine flow cytometry were used to characterize the prevalence and frequency of CD4+ and CD8+ memory T cells in 20 healthy CMV-seropositive subjects.
  
  
  RESULTS
  CD8+ T cell responses to pp65 were detected in 35% of subjects and to IE-1 in 40% of subjects. CD4+ T cell responses to pp65 were detected in 50% of subjects, but none were detected to IE-1. Several new IE-1 HLA class I epitopes were identified, including 4 restricted to HLA-C antigens. One region of IE-1 spanning amino acids 300 to 327 was rich in class I epitopes. The HLA class I restrictions of IE-1 peptides were more promiscuous than those of pp65 peptides.
  
  
  CONCLUSIONS
  Since naturally occurring CD4+ and CD8+ T cell responses to pp65 were detectable in many subjects, but only CD8+ T cell responses to IE-1 were detected, pp65 may be better than IE-1 for use in vaccine and adoptive immune therapies.
authors: Department of Transfusion Medicine, Warren G Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA. sslezak@cc.nih.gov
authors: Stefanie L
authors: SL
authors: Slezak
authors: Maria
authors: M
authors: Bettinotti
authors: Silvia
authors: S
authors: Selleri
authors: Sharon
authors: S
authors: Adams
authors: Francesco M
authors: FM
authors: Marincola
authors: David F
authors: DF
authors: Stroncek
mesh_terms: D000293:Adolescent; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology; D003587:Cytomegalovirus / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D006680:HLA Antigens / Q000235:genetics; D006262:Health; D006801:Humans; D017874:Immediate-Early Proteins / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D019151:Peptide Library; D010455:Peptides / Q000276:immunology; D010750:Phosphoproteins / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000276:immunology*; D055815:Young Adult
chemical_list: D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; C088645:IE1 protein, cytomegalovirus; D017874:Immediate-Early Proteins; D019151:Peptide Library; D010455:Peptides; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D007371:Interferon-gamma