Takahashi Yoshiyuki, McCoy J Philip, Carvallo Cristian, Rivera Candido, Igarashi Takehito, Srinivasan Ramaprasad, Young Neal S, Childs Richard W
Hematology Branch and Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892-1652, USA.
Blood. 2004 Feb 15;103(4):1383-90. doi: 10.1182/blood-2003-04-1281. Epub 2003 Oct 2.
It has been proposed that paroxysmal nocturnal hemoglobinuria (PNH) cells may proliferate through their intrinsic resistance to immune attack. To evaluate this hypothesis, we examined the impact of alloimmune pressure on PNH and normal cells in the clinical setting of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT). Five patients with severe PNH underwent HCT from an HLA-matched family donor after conditioning with cyclophosphamide and fludarabine. PNH neutrophils (CD15(+)/CD66b(-)/CD16(-)) were detected in all patients at engraftment, but they subsequently declined to undetectable levels in all cases by 4 months after transplantation. To test for differences in susceptibility to immune pressure, minor histocompatibility antigen (mHa)-specific T-cell lines or clones were targeted against glycosylphosphatidylinositol (GPI)-negative and GPI-positive monocyte and B-cell fractions purified by flow cytometry sorting. Equivalent amounts of interferon-gamma (IFN-gamma) were secreted following coculture with GPI-negative and GPI-positive targets. Furthermore, mHa-specific T-cell lines and CD8(+) T-cell clones showed similar cytotoxicity against both GPI-positive and GPI-negative B cells. Presently, all 5 patients survive without evidence of PNH 5 to 39 months after transplantation. These in vitro and in vivo studies show PNH cells can be immunologically eradicated following nonmyeloablative HCT. Relative to normal cells, no evidence for a decreased sensitivity of PNH cells to T-cell-mediated immunity was observed.
有人提出，阵发性夜间血红蛋白尿（PNH）细胞可能因其对免疫攻击的固有抗性而增殖。为了评估这一假设，我们在非清髓性异基因造血细胞移植（HCT）的临床环境中，研究了同种免疫压力对PNH细胞和正常细胞的影响。5例严重PNH患者在接受环磷酰胺和氟达拉滨预处理后，接受了来自HLA匹配的家族供体的HCT。在植入时，所有患者均检测到PNH中性粒细胞（CD15(+)/CD66b(-)/CD16(-)），但在移植后4个月时，所有病例中的这些细胞随后均降至检测不到的水平。为了测试对免疫压力敏感性的差异，将次要组织相容性抗原（mHa）特异性T细胞系或克隆靶向通过流式细胞术分选纯化的糖基磷脂酰肌醇（GPI）阴性和GPI阳性单核细胞及B细胞组分。与GPI阴性和GPI阳性靶细胞共培养后，分泌的γ干扰素（IFN-γ）量相当。此外，mHa特异性T细胞系和CD8(+) T细胞克隆对GPI阳性和GPI阴性B细胞均表现出相似的细胞毒性。目前，所有5例患者在移植后5至39个月均存活，无PNH迹象。这些体外和体内研究表明，非清髓性HCT后PNH细胞可被免疫清除。相对于正常细胞，未观察到PNH细胞对T细胞介导免疫的敏感性降低的证据。
