1Department of Medical Oncology, Medical School Hospital of Qingdao University, Qingdao 266003, China 2Department of Hematology, Medical School Hospital of Qingdao University, Qingdao 266003, China 3Department of Medical Cardiology, Zibo Central Hospital, Zibo 255000, China
Abstract. Aim: L615 leukemia cell line is a transplantable acute lymphocytic leukemia model with the CD4 positive phenotype. In this study, we explored whether tumor response specific T cells can be separated from the live leukemia mice or not. Methods: The mutant HGPRT- L615 cell line was first established. The splenocytes from HGPRT- L615 leukemia mice were cultured and expanded in mixed tumor-lymphocytes culture manner. The expanded T cells were sorted with FACScan. Then their killing capacity, IFN-g release as well as antitumor capacity in adoptive transfer experiments were analyzed. Results: The expanded response T cells are mostly CD4 positive. The CD4 positive T cells showed high release of IFN-g upon stimulation but lacked significant cytotoxicity. In immunochemotherapy model, these CD4 positive T cells can cure most leukemia mice. Conclusions: We demonstrated the feasibility of separation of tumor response specific CD4+ T cells from CD4+ L615 leukemia mice. These CD4+ T cells can cure leukemia mice upon adoptive transfer in combination with cyclophosphamide pretreatment.
Key Words:leukemia, immunotherapy, helper T cells.
