title: Absence of amplification of CD4+CD25(high) regulatory T cells during in vitro expansion of tumor-infiltrating lymphocytes in melanoma patients.
abstract: The exact role of CD4+CD25(high) regulatory T cells (Treg) in adoptive immunotherapy of melanoma is still to be determined, and an association between an expansion of Treg cells and the expansion of therapeutic tumor-infiltrating lymphocytes (TIL) remains unelucidated. In this context, the aim of our study was to determine whether functional Treg cells were detectable and amplified among in vitro-expanded TIL from 10 metastatic melanoma lymph nodes (LNs). In this study, we investigated the expression of forkhead/winged helix transcription factor 3 (Foxp3) in melanoma-invaded LNs and determined proportion and functionality of Treg cells among TIL extracted from these 10 metastatic melanoma LNs at different steps of their in vitro expansion. We found that metastatic melanoma LNs expressed very heterogeneous levels of Foxp3 and that CD4+CD25(high) Treg cells extracted from these LNs were detectable at each step of the in vitro culture of TIL but decreasing during the culture. In addition, functional assays demonstrated that these CD4+CD25(high) T cells were capable of suppressing autologous CD8+ and CD4+CD25- T cell proliferation. These cells were indeed Treg cells as they expressed Foxp3. In conclusion, our work suggests that CD4+CD25(high) Foxp3 expressing T cells are not expanded during in vitro amplification of TIL obtained from melanoma-invaded LNs.
authors.affiliation: INSERM, U601, 9 Quai Moncousu Nantes Cedex 01, France.
authors.forename: Anne Chantal
authors.initials: AC
authors.lastname: Knol
authors.forename: Fabrice
authors.initials: F
authors.lastname: Lemaître
authors.forename: Marie Christine
authors.initials: MC
authors.lastname: Pandolfino
authors.forename: Christelle
authors.initials: C
authors.lastname: Volteau
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Quéreux
authors.forename: Soraya
authors.initials: S
authors.lastname: Saiagh
authors.forename: Amir
authors.initials: A
authors.lastname: Khammari
authors.forename: Manuelle
authors.initials: M
authors.lastname: Viguier
authors.forename: Brigette
authors.initials: B
authors.lastname: Dréno
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D016219:Immunotherapy, Adoptive; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D008198:Lymph Nodes / Q000276:immunology / Q000473:pathology; D008207:Lymphatic Metastasis; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology* / Q000378:metabolism; D008545:Melanoma / Q000276:immunology* / Q000556:secondary; D012878:Skin Neoplasms / Q000276:immunology* / Q000473:pathology; D018709:Statistics, Nonparametric; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
chemical_list: D016207:Cytokines; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit