Cytomegalovirus (CMV) IE1- and pp65-specific CD8+ T cell responses broaden over time after primary CMV infection in infants.
Cytomegalovirus (CMV) infection remains a significant cause of morbidity and mortality in young children. We have previously shown that CD8+ T cell responses to CMV pp65 or IE1 protein were readily detectable in children with congenital or postnatal CMV infection. Here, we have further characterized the evolution of the peptide specificity of these responses in 7 infants<6 months of age at the start of the study. Thirteen pp65 and 15 IE1 peptides (median, 5 peptides/infant) were targeted, and most (61%) represented sequences not previously reported. Peptide specificity remained stable or broadened over time despite the clearance of CMV viremia. Loss of peptide recognition was not observed. Responses with the highest functional peptide avidity were not necessarily detected earliest. These data provide additional evidence that young infants can generate diverse CMV-specific CD8+ T cell responses but show that early responses may exhibit relatively focused peptide specificity and lower peptide avidity.
Gibson
Laura
L
Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA 01605, and Department of Pediatrics, Baystate Children's Hospital, Springfield, USA. laura.gibson@umassmed.edu
Dooley
Sheryl
S
Trzmielina
Sonia
S
Somasundaran
Mohan
M
Fisher
Donna
D
Revello
Maria Grazia
MG
Luzuriaga
Katherine
K
D000483:Alleles; D000595:Amino Acid Sequence; D000956:Antigens, Viral / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002460:Cell Line; D015331:Cohort Studies; D003587:Cytomegalovirus / Q000276:immunology* / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000097:blood / Q000151:congenital / Q000276:immunology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000276:immunology* / Q000378:metabolism; D007223:Infant; D007963:Leukocytes, Mononuclear / Q000276:immunology; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000276:immunology* / Q000378:metabolism; D013997:Time Factors; D019562:Viral Load; D014763:Viral Matrix Proteins / Q000276:immunology* / Q000378:metabolism; D014764:Viral Proteins / Q000276:immunology* / Q000378:metabolism
D000956:Antigens, Viral; C088645:IE1 protein, cytomegalovirus; D017874:Immediate-Early Proteins; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; D014764:Viral Proteins; C065418:cytomegalovirus matrix protein 65kDa