Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
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To control severe GvHD while maintaining strong GvL effects in the context of allo-stem cell transplantation (allo-SCT), a phase I/II clinical trial of infusions of donor lymphocytes transduced with the herpes simplex virus thymidine kinase (TK-DLI) started at the Tsukuba University Hospital. To date, five (2 AML, 2 ALL, and 1 MDS) out of eight patients enrolled in the trial received approximately 7x107 transduced cells per kilogram of body weight and four patients showed some clinical responses such inhibition of the leukemic cell proliferation or mitigation of lymph node swelling. Especially, one MDS patient achieved complete remission and has remained in CR for 2 years after the treatment. GvHD developed in two patients (1 acute and 1 chronic) and the acute (grade III) was successfully controlled by administration of ganciclovir without any immunosuppressive drugs. Since HSV-TK as a strong antigen induced CTLs against transduced cells in patients, however, TK-DLI is expected to provide a more effective adoptive immune cell therapy by performance just after allo-SCT where the patient's immune function is severely damaged.