Cytomegalovirus (CMV) phosphoprotein 65 makes a large contribution to shaping the T cell repertoire in CMV-exposed individuals.
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.
Kern
Florian
F
Institut für Medizinische Immunologie der Charité, Campus Mitte, 10098 Berlin, Germany. florian.kern@charite.de
Bunde
Torsten
T
Faulhaber
Nicole
N
Kiecker
Felix
F
Khatamzas
Elham
E
Rudawski
Ina-Maria
IM
Pruss
Axel
A
Gratama
Jan-Willem
JW
Volkmer-Engert
Rudolf
R
Ewert
Ralf
R
Reinke
Petra
P
Volk
Hans-Dieter
HD
Picker
Louis J
LJ
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*
D018984:Epitopes, T-Lymphocyte; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa