title: Cytomegalovirus (CMV) phosphoprotein 65 makes a large contribution to shaping the T cell repertoire in CMV-exposed individuals.
abstract: Antigen-specific, cytokine flow cytometry was used to analyze the prevalence and frequency of CD4 and CD8 memory T cells specific for the abundantly expressed cytomegalovirus (CMV) phosphoprotein 65 (pp65) in healthy CMV IgG-seropositive individuals. Stimulation of peripheral blood mononuclear cells with peptide pools and individual peptides derived from the pp65 amino acid sequence in 40 donors revealed that 63% of donors had a detectable CD4 T cell response and that 83% of donors had a detectable CD8 T cell response against this protein. The overall frequencies of T cells directed against pp65 were analyzed for 20 donors by stimulation with peptide pools covering the complete pp65 protein and were as high as 2 in 1000 and 9 in 1000 (median) peripheral blood CD4 and CD8 T cells, respectively. In addition, a comparison between CD4 responses to a CMV lysate containing various CMV proteins and pp65-specific responses in 9 donors indicated that pp65 was a dominant target of the CMV-specific CD4 T cell response in some, but not all, donors. Several new T cell epitopes were identified.
authors.affiliation: Institut für Medizinische Immunologie der Charité, Campus Mitte, 10098 Berlin, Germany. florian.kern@charite.de
authors.forename: Florian
authors.initials: F
authors.lastname: Kern
authors.forename: Torsten
authors.initials: T
authors.lastname: Bunde
authors.forename: Nicole
authors.initials: N
authors.lastname: Faulhaber
authors.forename: Felix
authors.initials: F
authors.lastname: Kiecker
authors.forename: Elham
authors.initials: E
authors.lastname: Khatamzas
authors.forename: Ina-Maria
authors.initials: IM
authors.lastname: Rudawski
authors.forename: Axel
authors.initials: A
authors.lastname: Pruss
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Gratama
authors.forename: Rudolf
authors.initials: R
authors.lastname: Volkmer-Engert
authors.forename: Ralf
authors.initials: R
authors.lastname: Ewert
authors.forename: Petra
authors.initials: P
authors.lastname: Reinke
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Volk
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Picker
mesh_terms: D000595:Amino Acid Sequence; 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; D006801:Humans; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000276:immunology*
chemical_list: D018984:Epitopes, T-Lymphocyte; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa