title: Recent thymic emigrants and subsets of naive and memory T cells in the circulation of patients with head and neck cancer.
abstract: Apoptosis of circulating CD8+ T lymphocytes is a frequent finding in patients with cancer. T-cell output by the thymus or antigen-driven expansion of circulating T cells could compensate for apoptosis and thus normalize their homeostasis. We studied the frequency of recent thymic emigrants (RTE) identified by T-cell receptor excision circles (TREC) and of naive and memory T-cell subsets in peripheral blood samples obtained from 39 patients with head and neck cancer (HNC) and 33 age-matched controls (NC). TREC numbers were determined by real-time quantitative PCR, and CD8+CD45RO-CD27+ or CD4+CD45RO-CD27+ T-cell subsets were quantified by flow cytometry. Age-associated decreases in TREC numbers and proportions of naive CD8+ and CD4+ T-cell subsets were significantly greater in cancer patients than NC. In contrast, the memory compartment was expanded, with increased proportions of CD4+CD45RO+ but not CD8+CD45RO+ T cells, in cancer patients vs. NC. These alterations did not normalize in patients who were NED. The data suggest that lower thymic output combined with rapid turnover of naive CD8+ T cells account for altered lymphocyte homeostasis in HNC patients. The defect persists long after curative treatments and may contribute to immune cell dysregulation in patients with cancer.
authors.affiliation: University of Pittsburgh Cancer Institute, PA 15213-1863, USA.
authors.forename: Iris
authors.initials: I
authors.lastname: Kuss
authors.forename: Carsten
authors.initials: C
authors.lastname: Schaefer
authors.forename: Tony E
authors.initials: TE
authors.lastname: Godfrey
authors.forename: Robert L
authors.initials: RL
authors.lastname: Ferris
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Harris
authors.forename: William
authors.initials: W
authors.lastname: Gooding
authors.forename: Theresa L
authors.initials: TL
authors.lastname: Whiteside
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D002465:Cell Movement / Q000276:immunology; D005260:Female; D006258:Head and Neck Neoplasms / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000473:pathology; D013950:Thymus Gland / Q000276:immunology* / Q000473:pathology
chemical_list: D011948:Receptors, Antigen, T-Cell