title: Increased populations of regulatory T cells in peripheral blood of patients with hepatocellular carcinoma.
abstract: Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide with a poor prognosis and one for which immunotherapy remains a viable option. Experimental tumor models have shown that regulatory T cells, a functionally unique subset of T cells, can suppress effective antitumor immune responses. This suppression might explain the poor outcome of some of the immunotherapy protocols currently being used. A better understanding of the role of regulatory T cells in HCC is important for design of future immunotherapy-based clinical protocols. We have studied regulatory T cells from 84 patients with HCC and 74 controls, including healthy donors, patients with chronic hepatitis B virus and hepatitis C virus infection and nonviral liver cirrhosis. Regulatory T cells were identified by fluorescence-activated cell sorting using a panel of antibodies and by real-time PCR analysis for Foxp3 expression. Functional studies were done to analyze their inhibitory role. Finally, regulatory T cells were analyzed in tumors and ascites from patients with HCC. Patients with HCC have increased numbers of CD4+CD25+ regulatory T cells in their peripheral blood, which express high levels of HLA-DR, GITR, and low or no CD45RA. These cells were anergic toward T-cell receptor stimulation and, when cocultured with activated CD4+CD25- cells, potently suppressed their proliferation and cytokine secretion. There were also high numbers of regulatory T cells in tumor-infiltrating lymphocytes of HCC patients comparable with the increase in their peripheral blood. Our data suggest that the increase in frequency of regulatory T cells might play a role in modulation of the immune response against HCC and could be important in design of immunotherapeutic approaches.
authors.affiliation: Department of Gastroenterology, Hepatology, and Endocrinology, Medizinische Hochschule Hannover, Hannover, Germany.
authors.forename: Lars A
authors.initials: LA
authors.lastname: Ormandy
authors.forename: Tina
authors.initials: T
authors.lastname: Hillemann
authors.forename: Heiner
authors.initials: H
authors.lastname: Wedemeyer
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.forename: Tim F
authors.initials: TF
authors.lastname: Greten
authors.forename: Firouzeh
authors.initials: F
authors.lastname: Korangy
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D006528:Carcinoma, Hepatocellular / Q000097:blood / Q000276:immunology*; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D051858:Forkhead Transcription Factors; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D015375:Receptors, Interleukin-2 / Q000276:immunology
chemical_list: D016207:Cytokines; D004268:DNA-Binding Proteins; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2