Retroviral transfer of T-cell receptors (TCR) to peripheral blood-derived T cells generates large numbers of T cells with the same antigen specificity, potentially useful for adoptive immunotherapy. One drawback of this procedure is the formation of mixed TCR dimers with unknown specificities due to pairing of endogenous and introduced TCR chains. We investigated whether ;D T cells can be an alternative effector population for TCR gene transfer because the ;DTCR is not able to form dimers with the ABTCR. Peripheral bloodderived ;D T cells were transduced with human leukocyte antigen (HLA) class I-or HLA class II-restricted minor histocompatibility antigen (mHag) or virus-specific TCRs. Because most ;D T cells do not express CD4 and CD8, we subsequently transferred these coreceptors. The TCR-transduced ;D T cells exerted high levels of antigen-specific cytotoxicity and produced IFN-; and IL-4, particularly in the presence of the relevant coreceptor. ;D T cells transferred with a TCR specific for the hematopoiesis-specific mHag HA-2 in combination with CD8 displayed high antileukemic reactivity against HA-2-expressing leukemic cells. These data show that transfer of ABTCRs to ;D T cells generated potent effector cells for immunotherapy of leukemia, without the expression of potentially hazardous mixed TCR dimers. (Cancer Res 2006; 66(6): 3331-7)
IntroductionCellular immunotherapy is a promising strategy for the treatment of cancer (1). However, adoptive transfer of sufficient numbers of antigen-specific T cells requires complex isolation methods and laborious and time-consuming tissue culture procedures. An alternative method to obtain large numbers of T cells with a defined antigen specificity is the retroviral transfer of a T-cell receptor (TCR). Because T-cell specificity is exclusively determined by the TCR, T-cell specificity can be functionally transferred to other T lymphocytes by retroviral TCR gene transfer. We and others have shown that transfer of human leukocyte antigen (HLA) class I-and HLA class II-restricted TCRs to CD8 + and CD4 + T cells, respectively, generated T cells with converted antigen-specific cytolytic activity and cytokine production (2-10).The potential in vivo efficacy of TCR-transferred T cells was shown in mouse models (8,9). The TCR-transferred T cells were activated in vivo, homed to effector sites, and contributed to tumor clearance.A potential disadvantage of TCR gene transfer to other ah T cells is the formation of mixed TCR dimers. Chains of the introduced TCR can pair with the endogenous TCR chains naturally expressed by the TCR-transferred T cells. The specificity of these mixed TCR dimers is unknown and, therefore, autoreactivity cannot be excluded. To limit the number of T cells with different TCR chains and thus the chance to generate autoreactive T cells, T cells with defined antigen specificity and, therefore, with a limited TCR repertoire can be selected as host cells for TCR gene transfer. We previously showed the reprogramming of cytomegalovirus (CMV)-specifi...