Transplant Immunology Laboratory, Cedars-Sinai Medical Center/UCLA School of Medicine, 8723 Alden Dr., Steven Spielberg Bldg., Los Angeles, CA 90048, USA.
Transpl Immunol. 2012 Mar;26(2-3):107-12. doi: 10.1016/j.trim.2011.11.001. Epub 2011 Nov 10.
Using a novel cytokine flow cytometry test (allo-CFC), we have previously shown that incubation of allogeneic cells with peripheral blood from highly-HLA sensitized (HS) patients results in reproducible gamma-interferon (IFNγ production in CD3(-) cells, and high (+) allo-CFC levels correlated with risk for antibody-mediated rejection (AMR). Here we report on identification of the cells and mechanisms responsible. The allo-CFC with/without modification was performed using blood from HS or normal individuals. IFNγ producing cells were CD3(-)/CD19(-), but CD3(-)/CD56(+). In vitro and in vivo B cell-depletion did not affect IFNγ production, demonstrating NK cells as the cells responsible for IFNγ production. NK cells from allo-CFC(+) or (-) individuals released significant amounts of IFNγ against target cells treated with serum from allo-CFC(+) individuals, but not allo-CFC(-) individuals. IFNγ release was abrogated by protein A/G treatment of the pretreated target cells, suggesting mediation by antibodies via FcγRIIIa (CD16). In conclusion, NK cell IFNγ release after allo-antigen exposure is mediated primarily through antibody-dependent cellular cytotoxicity (ADCC)-like mechanisms, suggesting that NK cells may be partially responsible for graft injury during AMR including C4d(-) AMR via ADCC, and could be a potential target for modification of this process.
利用一种新型细胞因子流式细胞术检测（allo-CFC），我们之前已经证明，将同种异体细胞与高度 HLA 致敏（HS）患者的外周血孵育，会导致 CD3(-) 细胞中重现γ干扰素（IFNγ）的产生，并且高水平的 allo-CFC 与抗体介导的排斥反应（AMR）的风险相关。在这里，我们报告了鉴定相关细胞和机制的研究结果。采用 HS 或正常个体的血液进行 allo-CFC 检测。产生 IFNγ 的细胞为 CD3(-)/CD19(-)，但为 CD3(-)/CD56(+)。体外和体内 B 细胞耗竭均不影响 IFNγ 的产生，表明 NK 细胞是产生 IFNγ 的细胞。来自 allo-CFC(+)或(-)个体的 NK 细胞在体外针对用 allo-CFC(+)个体血清处理的靶细胞释放大量 IFNγ，但针对 allo-CFC(-)个体的血清处理的靶细胞则不释放 IFNγ。经预处理的靶细胞用蛋白 A/G 处理可阻断 IFNγ 的释放，表明该过程是通过 FcγRIIIa（CD16）介导的抗体依赖性细胞毒性（ADCC）样机制。总之，NK 细胞在同种抗原暴露后释放 IFNγ 主要通过抗体依赖性细胞毒性（ADCC）样机制介导，表明 NK 细胞可能通过 ADCC 部分负责 AMR 期间的移植物损伤，包括 C4d(-) AMR，并且可能是该过程修饰的潜在靶点。
