To evaluate a combined cellular and humoral immunotherapy regimen in a mouse model of disseminated human neuroblastoma. We tested combinations of clinical-grade, isolated human gammadelta T cells with the humanized anti-GD2 antibody hu14.18 and a novel fusion cytokine, Fc-IL7.
gammadelta T cells were large-scale enriched from leukapheresis product obtained from granulocyte colony-stimulating factor-mobilized donors. gammadelta T cell cytotoxicity was tested in a europium-TDA release assay. The effect of Fc-IL7 on gammadelta T-cell survival in vitro was assessed by flow cytometry. NOD.CB17-Prkdc(scid)/J mice received 1 x 10(6) NB-1691 neuroblastoma cells via the tail vein 5 to 6 days before therapy began. Treatment, for five consecutive weeks, consisted of injections of 1 x 10(6) gammadelta T cells weekly, 1 x 10(6) gammadelta T cells weekly, and 20 microg hu14.18 antibody four times per week, or 1 x 10(6) gammadelta T cells weekly with 20 microg hu14.18 antibody four times per week, and 20 mug Fc-IL7 once weekly.
The natural cytotoxicity of gammadelta T cells to NB-1691 cells in vitro was dramatically enhanced by hu14.18 antibody. Fc-IL7 effectively kept cultured gammadelta T cells viable. Combination therapy with gammadelta T cells and hu14.18 antibody significantly enhanced survival (P = 0.001), as did treatment with gammadelta T cells, hu14.18 antibody, and Fc-IL7 (P = 0.005). Inclusion of Fc-IL7 offered an additional survival benefit (P=0.04).
We have shown a new and promising immunotherapy regimen for neuroblastoma that requires clinical evaluation. Our approach might also serve as a therapeutic model for other malignancies.
"The isolated cells were cytotoxic against a neuroblastoma cell line and an erythroleukemic line in vitro. With this process Otto and colleagues  combined gamma delta T cells with humoral immunotherapy in a mouse model of disseminated neuroblastoma. Anti-GD2 is a monoclonal antibody that binds to disialoganglioside GD-2, which is expressed by most neuroblastoma cells . "
[Show abstract][Hide abstract] ABSTRACT: The field of allogeneic transplantation has made vast improvements since its inception in 1968. Improvements in supportive care have greatly improved survival. Delayed immune reconstitution, graft versus host disease, and relapse of disease still pose great obstacles. This article has highlighted novel strategies for using cellular therapy in conjunction with hematopoietic cell transplantation (HCT) that potentially may lead to improved clinical outcomes for patients undergoing HCT in the future.
Pediatric Clinics of North America 09/2006; 53(4):685-98. DOI:10.1016/j.pcl.2006.05.007 · 2.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gammadelta T cells are a unique and minor T-cell subset that differs from conventional alphabeta T cells by virtue of their tissue localization and antigen processing requirements. We have previously shown that ex vivo-activated gammadelta T cells are able to prevent graft rejection without causing clinically significant graft-versus-host disease (GVHD). In the present study, we examined how gammadelta T cells facilitate alloengraftment and to what extent mechanisms used by conventional alphabeta T cells are also used by gammadelta T cells. We observed that, unlike alphabeta T cells, for which CD8(+) T cells are primarily responsible for facilitating engraftment, purified CD8(+)gammadelta(+) T cells administered at the same fractional dose as for the unseparated activated gammadelta T-cell population were insufficient to prevent graft rejection. Furthermore, the ability to prevent graft rejection was not affected by the absence of fully functional fas ligand or perforin cytotoxic pathways, nor was it contingent on the ability of gammadelta T cells to recognize recipient major histocompatibility process alloantigens. Repetitive infusions of a suboptimal dose of gammadelta T cells however were able to rescue mice from graft rejection, suggesting that the persistence of these cells in vivo was critical in facilitating alloengraftment. These studies demonstrate that gammadelta T cells do not use mechanisms used by conventional nontolerant alphabeta T cells to prevent graft rejection. The ability of these cells to promote engraftment without causing GVHD further distinguishes these cells from alphabeta T cells and may be an attribute that can be exploited in the clinical transplantation setting.
Biology of Blood and Marrow Transplantation 12/2006; 12(11):1125-34. DOI:10.1016/j.bbmt.2006.08.033 · 3.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human Vγ2Vδ2 T cells play important roles in mediating immunity against microbial pathogens and have potent anti-tumor activity. Vγ2Vδ2 T cells recognize the pyrophosphorylated isoprenoid intermediates (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), an intermediate in the foreign 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway, and isopentenyl pyrophosphate (IPP), an intermediate in the self-mevalonate pathway. Infection with bacteria and protozoa using the MEP pathway leads to the rapid expansion of Vγ2Vδ2 T cells to very high numbers through preferential recognition of HMBPP. Activated Vγ2Vδ2 T cells produce proinflammatory cytokines and chemokines, kill infected cells, secrete growth factors for epithelial cells, and present antigens to αβ T cells. Vγ2Vδ2 T cells can also recognize high levels of IPP in certain tumors and in cells treated with pharmacological agents, such as bisphosphonates and alkylamines, that block farnesyl pyrophosphate synthase. Activated Vγ2Vδ2 T cells are able to kill most tumor cells because of recognition by T-cell receptor and natural killer receptors. The ubiquitous nature of the antigens converts essentially all Vγ2Vδ2 T cells to memory cells at an early age. Thus, primary infections with HMBPP-producing bacteria are perceived by Vγ2Vδ2 T cells as a repeat infection. Extensive efforts are underway to harness these cells to treat a variety of cancers and to provide microbial immunity.
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