title: Terminally differentiated CD8 cells in HIV-infected children: HIV-GAG/POL specificity and IFN-γ production.
abstract: BACKGROUND
  CD8 cells are key to antiviral immunity and can be divided by phenotype into early (CD28+ CD27+), intermediate (CD28-CD27+) and terminally differentiated subsets (CD28- CD27-). Despite effective HAART there is an unexplained expansion of CD8+CD28-CD27-T cells in HIV-infected children. The cytokine production and specificity of this terminally differentiated CD8 T cell subset in chronic virus infection is unclear. PATIENTS, METHODS & RESULTS: In a cohort of 26 HIV-infected children the cytokine production of terminally differentiated CD8 cells was analyzed by intracellular staining and FACS analysis and was compared to children with chronic hepatitis B infection and to healthy children. The specificity of CD8 subsets was analyzed by staining with Gag/Pol tetramers in a cohort of 13 patients. We show that an increased production of interferon-γ in terminally and early/intermediate differentiated CD8 cell subsets after stimulation is specific for HIV-infection. The expanded population of terminally differentiated CD8+CD28-CD27- T cells does include HIV Gag/Pol specific T cells in adults but not in children.
  
  
  CONCLUSIONS
  The expansion of terminally differentiated CD8 cells might be important for immunomodulation but in children it does not appear to play a role in HIV Gag and Pol specific immunity.
authors.affiliation: Centre for Pediatric and Adolescent Medicine, HELIOS Klinikum Krefeld, Lutherplatz 40, Krefeld, Germany. daniel.delbeck@helios-kliniken.de
authors.forename: D
authors.initials: D
authors.lastname: Delbeck
authors.forename: M
authors.initials: M
authors.lastname: Siepermann
authors.forename: O
authors.initials: O
authors.lastname: Feyen
authors.forename: S
authors.initials: S
authors.lastname: Wirth
authors.forename: U
authors.initials: U
authors.lastname: Baumann
authors.forename: U
authors.initials: U
authors.lastname: Wintergerst
authors.forename: M
authors.initials: M
authors.lastname: Oette
authors.forename: R
authors.initials: R
authors.lastname: Adam
authors.forename: M
authors.initials: M
authors.lastname: Jetzek-Zader
authors.forename: T
authors.initials: T
authors.lastname: Niehues
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000918:Antibody Specificity / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D019694:Hepatitis B, Chronic / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D055815:Young Adult; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000276:immunology*; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000276:immunology*
chemical_list: D054301:gag Gene Products, Human Immunodeficiency Virus; D054302:pol Gene Products, Human Immunodeficiency Virus; D007371:Interferon-gamma