anti-leukemia activity of in vitro-expanded human gamma delta t cells in a xenogeneic ph+ leukemia model抗白血病活性vitro-expanded人类异种的ph值+γδt细胞白血病模型.pdfVIP

Anti-Leukemia Activity of In Vitro-Expanded Human Gamma Delta T Cells in a Xenogeneic Ph+ Leukemia Model 1 2 1 1 1 Gabrielle M. Siegers *, Tania C. Felizardo , A. Mark Mathieson , Yoko Kosaka , Xing-Hua Wang , Jeffrey A. Medin2, Armand Keating1 1 Cell Therapy Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada, 2 Ontario Cancer Institute, Toronto, Ontario, Canada Abstract Gamma delta T cells (GDTc) lyse a variety of hematological and solid tumour cells in vitro and in vivo, and are thus promising candidates for cellular immunotherapy. We have developed a protocol to expand human GDTc in vitro, yielding highly cytotoxic Vgamma9/Vdelta2 CD27/CD45RA double negative effector memory cells. These cells express CD16, CD45RO, CD56, CD95 and NKG2D. Flow cytometric, clonogenic, and chromium release assays confirmed their specific cytotoxicity against Ph+ cell lines in vitro. We have generated a fluorescent and bioluminescent Ph+ cell line, EM-2eGFPluc, and established a novel xenogeneic leukemia model. Intravenous injection of EM-2eGFPluc into NOD.Cg-Prkdcscid Il2rgtm1Wjl/ SzJ (NSG) mice resulted in significant dose-dependent bone marrow engraftment; lower levels engrafted in blood, lung, liver and spleen. In vitro-expanded human GDTc injected intraperitoneally were found at higher levels in blood and organs compared to those injected intravenously; GDTc survived at least 33 days post-injection. In therapy experiments, we documented decreased bone marrow leukemia burden in mice treated with GDTc. Live GDTc were found in spleen and bone marrow at endpoi