Phenotypic and functional characteristics of CD4 super(+)CD39 super(+) FOXP3 super(+) and CD4 super(+)CD39 super(+)FOXP 3 super(neg) T-cell subsets in cancer patients

• Published in: European journal of immunology 2012-07, Vol.42 (7), p.1876-1885
• Main Authors: Schuler, Patrick J, Schilling, Bastian, Harasymczuk, Malgorzata, Hoffmann, Thomas K, Johnson, Jonas, Lang, Stephan, Whiteside, Theresa L
• Format: Article
• Language: English
• ISSN: 0014-2980; 1521-4141
• DOI: 10.1002/eji.201142347

Human CD4 super(+)CD39 super(+) regulatory T (Treg) cells hydrolyze exogenous adenosine triphosphate (ATP) and participate in immunosuppressive adenosine production. They contain two T-cell subsets whose role in mediating suppression is not understood. Frequencies of both CD4 super(+)CD39 super(+) subsets were evaluated in peripheral blood lymphocytes of 57 cancer patients and in tumor infiltrating lymphocytes (TILs) of 6 patients. CD4 super(+)CD39 super(+) and CD4 super(+)CD39 super(neg) T cells isolated using immunobeads and cell sorting were cultured under various conditions. Their conversion into CD39 super(+)FOXP3 super(+)CD 25 super(+) or CD39 super(+)FOX super(neg)CD 25 super(neg) cells was monitored by multiparameter flow cytometry. Hydrolysis of exogenous ATP was measured in luminescence assays. Two CD4 super(+)CD39 super(+) cell subsets differing in expression of CD25, FOXP3, CTLA-4, CD121a, PD-1, latency associated peptide (LAP), glycoprotein A repetitions predominant (GARP), and the cytokine profile accumulated with equal frequencies in the blood and tumor tissues of cancer patients. The frequency of both subsets was significantly increased in cancer. CD39 expression levels correlated with the subsets' ability to hydrolyze ATP. Conventional CD4 super(+)CD39 super(neg) T cells incubated with IL-2 + TGF-[beta] expanded to generate CD4 super(+)CD39 super(+)FOXP 3 super(+) Treg cells, while CD4 super(+)CD39 super(+)FOXP 3 super(neg)CD25 super(neg) subset cells stimulated via the TCR and IL-2 converted to FOXP3 super(+)CTLA4 super(+)C D25 super(+) TGF-[beta]-expressing Treg cells. Among CD4 super(+)CD39 super(+) Treg cells, the CD4 super(+)CD39 super(+)FOXP 3 super(neg)CD25 super(neg) subset serves as a reservoir of cells able to convert to Treg cells upon activation by environmental signals.