HLA monomers as a tool to monitor indirect allorecognition.
HLA monomers as a tool to monitor indirect allorecognition.
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DOI：
10.1097/tp.0000000000000113
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发表时间：
2014-06-15
期刊：
影响因子：
6.2
通讯作者：
van Kooten C
中科院分区：
文献类型：
--
作者：
Breman E;van Miert PP;van der Steen DM;Heemskerk MH;Doxiadis II;Roelen D;Claas FH;van Kooten C
供体抗原的识别可以通过两种不同的途径发生：直接途径（供体细胞上的非自身HLA）和间接途径（供体衍生肽在受体细胞上的自我限制呈递）。间接异体识别在体液性排斥反应的发展中起重要作用；因此，人们对间接同种异体反应t细胞的监测越来越感兴趣。我们使用体外模型来确定间接呈递的最佳要求，并评估该系统中半直接呈递的风险。hla型单核细胞来源的树突状细胞（moDCs）与细胞碎片或坏死细胞孵育，并与间接或直接同种异体反应性t细胞克隆孵育。通过增殖或细胞因子分泌来测定t细胞的反应性。HLA型moDC、单核细胞或pbmc与HLA I类单体一起培养，并与直接或间接的t细胞克隆结合。虽然两者都被有效地吸收，但当使用细胞时，同种异体CD4（间接）和CD8 t细胞克隆（直接）测量的同种异体反应性仅限于半直接途径。相比之下，HLA-A2单体不仅被hla型moDC、单核细胞和pbmc有效地吸收，而且还被加工和呈递。CD4 t细胞克隆对IFN-γ产生和增殖的剂量依赖性诱导显示了活化。当单体在t细胞存在下培养较长时间（24-48小时）时，抗原呈递效率最高。使用这种方法，CD8 t细胞克隆未观察到反应性，证实没有半直接的同种异体反应性。我们已经开发了一个系统，可以用来监测间接同种异体反应t细胞。
Recognition of donor antigens can occur through two separate pathways: the direct pathway (non-self HLA on donor cells) and the indirect pathway (self-restricted presentation of donor derived peptides on recipient cells). Indirect allorecognition is important in the development of humoral rejection; therefore, there is an increasing interest in the monitoring of indirect alloreactive T-cells. We have used an in vitro model to determine the optimal requirements for indirect presentation and assessed the risk for semidirect presentation in this system. HLA-typed monocyte-derived dendritic cells (moDCs) were incubated with cellular fragments or necrotic cells and incubated with either indirect or direct alloreactive T-cell clones. T-cell reactivity was measured through proliferation or cytokine secretion. HLA-typed moDC, monocytes, or PBMCs were incubated with HLA class I monomers, in combination with either direct/indirect T-cell clones. Although both were efficiently taken up, alloreactivity was limited to the semi-direct pathway, as measured by allospecific CD4 (indirect) and CD8 T-cell clones (direct) when cells were used. In contrast, HLA-A2 monomers were not only efficiently taken up but also processed and presented by HLA-typed moDC, monocytes, and PBMCs. Activation was shown by a dose-dependent induction of IFN-γ production and proliferation by the CD4 T-cell clone. Antigen presentation was most efficient when the monomers were cultured for longer periods (24–48 hr) in the presence of the T-cells. Using this method, no reactivity was observed by the CD8 T-cell clone, confirming no semidirect alloreactivity. We have developed a system that could be used to monitor indirect alloreactive T-cells.