title: Immune activation status of CD8+ T cells infiltrating non-small cell lung cancer.
abstract: In a variety of human cancers, the presence of tumor-infiltrating T lymphocytes (TILs) is associated with tumor regression and favorable prognosis. Local interferon (IFN)-gamma secretion from activated T cells is supposed to induce a specific immune response leading to tumor-specific cytotoxicity. Nonetheless, significance and properties of TILs still remains controversial in lung cancer patients. We determined CD8+ T cell counts in 31 patients with non-small cell lung cancer (NSCLC) by immunohistochemistry, and assessed T-cell immune activation status in a subset of patients by measuring IFN-gamma mRNA expression by quantitative PCR (TaqMan). Semi-quantitative immunohistochemical analysis revealed significantly higher CD8+ T cell counts within the tumor as when compared to the invasive margin. CD8+ T cells immune activation status, represented in the IFN-gamma/CD8 mRNA ratio, correlated with the median number of CD8+ T cells presented at the tumor-host interface. Neither tumor histology and grade, nor CD8+ T cell counts and IFN-gamma/CD8 ratio could demonstrate an influence on overall survival in these patients. Our results indicate that CD8+ T cells infiltrating the tumor cell nests may be inadequately activated and thus incapable of mounting an effective anti-tumor immune response.
authors.affiliation: Department of Oncology, University Hospital Zürich, Rämistrasse 100, CH-8091 Zurich, Switzerland. andreas.trojan@usz.ch
authors.forename: Andreas
authors.initials: A
authors.lastname: Trojan
authors.forename: Mirjana
authors.initials: M
authors.lastname: Urosevic
authors.forename: Reinhard
authors.initials: R
authors.lastname: Dummer
authors.forename: Robin
authors.initials: R
authors.lastname: Giger
authors.forename: Walter
authors.initials: W
authors.lastname: Weder
authors.forename: Rolf A
authors.initials: RA
authors.lastname: Stahel
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology*; D016207:Cytokines / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000276:immunology*; D008213:Lymphocyte Activation; D009367:Neoplasm Staging; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis
chemical_list: D016207:Cytokines