title: A short CD3/CD28 costimulation combined with IL-21 enhance the generation of human memory stem T cells for adoptive immunotherapy.
abstract: Immunotherapy based on the adoptive transfer of gene modified T cells is an emerging approach for the induction of tumor-specific immune responses. Memory stem T cells, due to their enhanced antitumor and self-renewal capacity, have become potential candidate for adoptive T cell therapy of cancer. Methods to generate memory stem T cells ex vivo rely on CD3/CD28 costimulation and the use of cytokines such as IL-7 and IL-15 during the entire culture period. However, a strong costimulation may induce differentiation of memory stem T cells to effector memory T cells. Here we show that manipulation of the length of the costimulation and addition of IL-21 enhance the ex vivo expansion of memory stem T cells.
  
  
  
  Purified naïve T cells from healthy donors were cultured in the presence of anti-CD3/CD28 coated beads, IL-7, IL-15 and/or IL-21 (25 ng/ml). T cells phenotype from the different memory and effector subpopulations were analyzed by multiparametric flow cytometry.
  
  
  
  A short anti-CD3/CD28 costimulation of naïve T cells, combined with IL-7 and IL-15 significantly increased the frequencies of CD4(+) and CD8(+) memory stem T cells ex vivo, compared to a prolonged costimulation (34.6 ± 4.4 % vs 15.6 ± 4.24 % in CD4(+); p = 0.008, and 20.5 ± 4.00 % vs 7.7 ± 2.53 % in CD8(+); p = 0.02). Moreover, the addition of IL-21 to this condition further enhanced the enrichment and expansion of CD4(+) and CD8(+) memory stem T cells with an increase in the absolute numbers (0.7 × 10(6) ± 0.1 vs 0.26 × 10(6) ± 0.1 cells for CD4(+); p = 0.002 and 1.1 × 10(6) ± 0.1 vs 0.27 × 10(6) ± 0.1 cells for CD8(+); p = 0.0002; short + IL-21 vs long).
  
  
  
  These new in vitro conditions increase the frequencies and expansion of memory stem T cells and may have relevant clinical implications for the generation of this memory T cell subset for adoptive cell therapy of patients with cancer.
authors.affiliation: Hematology Service, Hospital de la Santa Creu i Sant Pau, Mas Casanovas 90, 08041, Barcelona, Spain.|Autonomous University, Barcelona, Spain.|Laboratory of Experimental Hematology-IIB, Institut Recerca Hospital de la Santa Creu I Sant Pau, Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Alvarez-Fernández
authors.affiliation: Hematology Service, Hospital de la Santa Creu i Sant Pau, Mas Casanovas 90, 08041, Barcelona, Spain.|Autonomous University, Barcelona, Spain.|Laboratory of Experimental Hematology-IIB, Institut Recerca Hospital de la Santa Creu I Sant Pau, Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Escribà-Garcia
authors.affiliation: Autonomous University, Barcelona, Spain.|IIB-Institut Recerca Hospital de la Santa Creu I Sant Pau, Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Vidal
authors.affiliation: Hematology Service, Hospital de la Santa Creu i Sant Pau, Mas Casanovas 90, 08041, Barcelona, Spain.|Autonomous University, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sierra
authors.affiliation: Hematology Service, Hospital de la Santa Creu i Sant Pau, Mas Casanovas 90, 08041, Barcelona, Spain. jbriones@santpau.cat.|Autonomous University, Barcelona, Spain. jbriones@santpau.cat.
authors.forename: J
authors.initials: J
authors.lastname: Briones
mesh_terms: D018106:CD28 Antigens / Q000378:metabolism*; D017252:CD3 Complex / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D005822:Genetic Vectors / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects*; D016219:Immunotherapy, Adoptive; D007378:Interleukins / Q000494:pharmacology*; D016086:Lentivirus / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology*; D014019:Tissue Donors; D014161:Transduction, Genetic; D000098546:Interleukin-21
chemical_list: D018106:CD28 Antigens; D017252:CD3 Complex; D007378:Interleukins; D049452:Green Fluorescent Proteins; D000098546:Interleukin-21
keywords: IL-21; Immunotherapy; Memory stem T cell