Osman Y, Takahashi M, Zheng Z, Koike T, Toba K, Liu A, Furukawa T, Aoki S, Aizawa Y
First Department of Internal Medicine, School of Medicine, Niigata University, Japan.
Leukemia. 1999 Feb;13(2):166-74. doi: 10.1038/sj.leu.2401311.
Dendritic cells (DC), the most potent 'professional' antigen-presenting cells, hold promise for improving the immunotherapy of cancer. In this study, we investigated the ability of normal donor DC pulsed ex vivo with 12 mer bcr-abl (b3a2) peptide to generate b3a2-specific autologous or HLA-identical sibling donor's cytotoxic T-lymphocytes (CTL). DC that were grown from normal peripheral blood adherent cells or purified DC precursors in the presence of GM-CSF and IL-4, were pulsed with b3a2-peptide then were induced to become mature and functional cells by the addition of TNF-alpha. These peptide-pulsed mature DC elicited a potent b3a2-specific CTL response in vitro. The b3a2-peptide pulsed DC-primed peripheral blood lymphocytes (PBL) displayed significantly higher cytotoxic activity compared with peptide non-pulsed DC-primed PBL against target cells, which are b3a2 positive marrow cells derived from HLA-identical sibling chronic myelogenous leukemia (CML) patient, or peptide-pulsed autologous macrophages (P < 0.001). In addition, the b3a2 peptide-pulsed DC-primed and non-pulsed DC-primed PBL showed no cytotoxic response against peptide non-pulsed autologous macrophages. These findings revealed that normal donor PBL pre-immunized with b3a2-peptide pulsed autologous DC could increase the graft-versus-leukemia effect without exaggerating graft-versus-host-disease. Both CD8+ and CD4+ T lymphocytes were shown to be involved in the effector cell populations. The b3a2 peptide-pulsed DC-primed T cells were significantly superior in their production of GM-CSF and TNF-alpha compared with peptide non-pulsed DC-primed T cells. These intriguing preclinical results imply the feasibility of developing b3a2 peptide-DC based protocol for in vitro sensitization of normal donor leukocytes before donor leukocyte transfusions for patients with CML, who relapsed after HLA-matched sibling bone marrow transplantation.
树突状细胞（DC）是最强大的“专职”抗原呈递细胞，有望改善癌症免疫治疗。在本研究中，我们调查了用12聚体bcr-abl（b3a2）肽在体外脉冲处理的正常供体DC产生b3a2特异性自体或HLA相同同胞供体细胞毒性T淋巴细胞（CTL）的能力。从正常外周血贴壁细胞或在GM-CSF和IL-4存在下纯化的DC前体培养而来的DC，用b3a2肽脉冲处理，然后通过添加TNF-α诱导成为成熟且有功能的细胞。这些肽脉冲处理的成熟DC在体外引发了强大的b3a2特异性CTL反应。与未用肽脉冲处理的DC引发的外周血淋巴细胞（PBL）相比，用b3a2肽脉冲处理的DC引发的PBL对靶细胞（来自HLA相同同胞慢性粒细胞白血病（CML）患者的b3a2阳性骨髓细胞或肽脉冲处理的自体巨噬细胞）显示出显著更高的细胞毒性活性（P < 0.001）。此外，用b3a2肽脉冲处理的DC引发的和未用肽脉冲处理的DC引发的PBL对未用肽脉冲处理的自体巨噬细胞均未显示出细胞毒性反应。这些发现表明，用b3a2肽脉冲处理的自体DC预先免疫的正常供体PBL可以增强移植物抗白血病效应，而不会加剧移植物抗宿主病。CD8 +和CD4 + T淋巴细胞均显示参与效应细胞群体。与未用肽脉冲处理的DC引发的T细胞相比，用b3a2肽脉冲处理的DC引发的T细胞在GM-CSF和TNF-α的产生方面明显更优。这些有趣的临床前结果表明，对于在HLA匹配的同胞骨髓移植后复发的CML患者，在进行供体白细胞输注之前，开发基于b3a2肽-DC的方案用于体外致敏正常供体白细胞是可行的。
