title: Maintenance of large subpopulations of differentiated CD8 T-cells two years after cytomegalovirus infection in Gambian infants.
abstract: BACKGROUND
  In a previously published study, we found that large differentiated subpopulations of CD8 T-cells emerged rapidly after CMV infection in young infants and persisted throughout the following year. Here we describe a follow-up study conducted on the same infants to establish whether the differentiated subpopulations continued through the second year post-infection.
  CMV-specific cells identified using tetramers remained more activated and differentiated than the overall CD8 population. The large subpopulation of differentiated cytotoxic (CD28(-)CD62L(-)Bcl-2(low)CD95(+)perforin(+)) cells that emerged rapidly after infection remained stable after two years. No similar subpopulation was found in CMV-uninfected infants indicating that two years after infection, CMV remained a major factor in driving CD8 T-cell differentiation. Although markers of activation (CD45R0 and HLA-D) declined throughout the first year, HLA-D expression continued to decline during the second year and CD45R0 expression increased slightly. The age-related increase in IFNgamma response observed during the first year continued but was non-significant during the second year, indicating that the rate of functional improvement had slowed substantially. CONCLUSIONS / SIGNIFICANCE: The large differentiated subpopulations of CD8 T-cells that had emerged immediately after CMV infection persisted through the second year post-infection, while levels of activation and functional capacity remained fairly constant.
authors.affiliation: MRC Laboratories Gambia, Banjul, The Gambia. djcm1@liverpool.ac.uk
authors.forename: David J C
authors.initials: DJ
authors.lastname: Miles
authors.forename: Marianne
authors.initials: M
authors.lastname: van der Sande
authors.forename: David
authors.initials: D
authors.lastname: Jeffries
authors.forename: Steve
authors.initials: S
authors.lastname: Kaye
authors.forename: Olubukola
authors.initials: O
authors.lastname: Ojuola
authors.forename: Mariama
authors.initials: M
authors.lastname: Sanneh
authors.forename: Momodou
authors.initials: M
authors.lastname: Cox
authors.forename: Melba S
authors.initials: MS
authors.lastname: Palmero
authors.forename: Ebrima S
authors.initials: ES
authors.lastname: Touray
authors.forename: Pauline
authors.initials: P
authors.lastname: Waight
authors.forename: Sarah
authors.initials: S
authors.lastname: Rowland-Jones
authors.forename: Hilton
authors.initials: H
authors.lastname: Whittle
authors.forename: Arnaud
authors.initials: A
authors.lastname: Marchant
mesh_terms: D001724:Birth Weight; D018414:CD8-Positive T-Lymphocytes; D002675:Child, Preschool; D015331:Cohort Studies; D003586:Cytomegalovirus Infections / Q000175:diagnosis / Q000276:immunology*; D005500:Follow-Up Studies; D005714:Gambia; D006801:Humans; D007223:Infant; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D013997:Time Factors