title: Addition of interleukin-21 for expansion of T-cells for adoptive immunotherapy of murine melanoma.
abstract: We previously demonstrated that interleukin (IL)-7/15 was superior to IL-2 for expansion of T cells in vitro for adoptive immunotherapy. We sought to ascertain whether IL-21 would further improve yield and therapeutic efficacy of T cells in culture. Naïve T cell receptor (TcR) transgenic splenocytes or antigen-sensitized lymph node cells were harvested from PMEL-1 mice and exposed to bryostatin-1 and ionomycin (B/I) for 18 h. Cells were then cultured in IL-2, IL-21, IL-7/15 or IL-7/15/21 for six days. Harvested cells were analyzed by flow cytometry and used to treat C57Bl/6 mice injected intravenously with B16 melanoma. Lungs were harvested and metastases counted 14 days after treatment. Culturing lymphocytes in IL-7/15/21 increased expansion compared to IL-2 or IL-7/15. IL-21 and IL-7/15/21 increased CD8+ cells compared to IL-2 or IL-7/15. IL-21 preferentially expanded a CD8+CD44-CD62L+ T "naïve" population, whereas IL-7/15/21 increased CD8+CD44+CD62Lhigh central-memory T cells. T cells grown in IL-7/15/21 were more effective at reducing metastases than IL-2. The addition of IL-21 to IL-7/15 induced greater expansion of lymphocytes in culture and increased the yield of CD8+ T central-memory cells vs. IL-7/15 alone. This may have significant impact on future clinical trials of adoptive immunotherapy, particularly for generating adequate numbers of lymphocytes for treatment.
authors.affiliation: Department of Surgery, Virginia Commonwealth University Health System, Richmond, VA 23298, USA. ckzoon@comcast.net.
authors.forename: Christine Kathryn
authors.initials: CK
authors.lastname: Zoon
authors.affiliation: Department of Biostatistics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA. wwan@vcu.edu.
authors.forename: Wen
authors.initials: W
authors.lastname: Wan
authors.affiliation: Division of Surgical Oncology, Virginia Commonwealth University Massey Cancer Center, Richmond, VA 23298, USA. lgraham2@mcvh-vcu.edu.
authors.forename: Laura
authors.initials: L
authors.lastname: Graham
authors.affiliation: Division of Surgical Oncology, Virginia Commonwealth University Massey Cancer Center, Richmond, VA 23298, USA. hdbear@vcu.edu.
authors.forename: Harry D
authors.initials: HD
authors.lastname: Bear
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D003520:Cyclophosphamide / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016219:Immunotherapy, Adoptive; D007371:Interferon-gamma / Q000378:metabolism; D007378:Interleukins / Q000502:physiology*; D008175:Lung Neoplasms / Q000556:secondary / Q000628:therapy*; D008546:Melanoma, Experimental / Q000473:pathology / Q000628:therapy*; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D013601:T-Lymphocytes / Q000502:physiology*; D000098546:Interleukin-21
chemical_list: D007166:Immunosuppressive Agents; D007378:Interleukins; D007371:Interferon-gamma; D003520:Cyclophosphamide; D000098546:Interleukin-21