title: C1.7 antigen expression on CD8+ T cells is activation dependent: increased proportion of C1.7+CD8+ T cells in HIV-1-infected patients with progressing disease.
abstract: The C1.7 Ag is a surface marker previously shown to be expressed on all NK cells and on a subset of CD8+ T cells. We report in this study that C1.7 Ag expression on peripheral blood-derived CD8+ T cells overlaps with activation markers S6F1high and CD29high and is reciprocally expressed with CD62L. C1.7 Ag expression can be induced in vitro on CD8+ T cells by anti-CD3 cross-linking, suggesting that C1.7 Ag is activation dependent. In contrast to NK cells, C1.7 Ag does not signal on CD8+ T cells, nor does it induce redirected lysis upon ligation. The proportion of C1.7 Ag+CD8+ T cells is increased in HIV-infected patients compared with healthy donors. In 69 HIV-infected patients, we observed a significant inverse correlation between the percentage of C1.7 Ag-expressing CD8+ T cells and the absolute CD4+ T cell count. Two-year clinical follow-up of patients with initial CD4+ T cell count of >400 cells/mm3 and a normal proportion of C1.7 Ag+CD8+ T cells revealed that these patients were clinically stable with minimal HIV-associated symptoms. In contrast, 10 of 12 patients with CD4+ T cell counts of >400 cells/mm3 and an elevated proportion of C1.7 Ag+CD8+ T cells were symptomatic. ANOVA analysis of patients indicates that C1.7 Ag is a better predictor of disease progression than CD4 count. Overall, our findings indicate that C1.7 Ag is the first described marker for activated/memory CD8+ T cells and a useful parameter for evaluating the level of CD8+ T cell activation in vivo.
authors.affiliation: The Wistar Institute, Philadelphia, PA 19104, USA.
authors.forename: D
authors.initials: D
authors.lastname: Peritt
authors.forename: D A
authors.initials: DA
authors.lastname: Sesok-Pizzini
authors.forename: R
authors.initials: R
authors.lastname: Schretzenmair
authors.forename: R R
authors.initials: RR
authors.lastname: Macgregor
authors.forename: N M
authors.initials: NM
authors.lastname: Valiante
authors.forename: X
authors.initials: X
authors.lastname: Tu
authors.forename: G
authors.initials: G
authors.lastname: Trinchieri
authors.forename: M
authors.initials: M
authors.lastname: Kamoun
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis* / Q000097:blood; D017252:CD3 Complex / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D003601:Cytotoxicity Tests, Immunologic; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008297:Male; D016853:Muromonab-CD3 / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D016853:Muromonab-CD3