Development of the new monitoring system for acute rejection in clinicallung and lung-heart transplantation, focusing on the cytotoxicity specific to the major histocompatibility complex class I antigens of the donor organ.

本研究旨在建立临床肺、心肺移植急性排斥反应监测系统。为此目的，检测了来自受体的淋巴细胞的细胞毒性。从支气管肺泡灌洗（BAL）中分离淋巴细胞，并以一系列b淋巴母细胞样细胞系（LCL）为靶，作为标准细胞介导的淋巴细胞溶解（CML）试验的效应细胞。在没有巨细胞病毒（CMV）感染的急性排斥反应中，LCL靶点的平均溶解率（即细胞毒性）明显高于没有巨细胞病毒或巨细胞病毒感染的急性排斥反应，当这些靶点共享一种或多种HLA I类致敏供体同种抗原（“I类相关靶点”）时。特别是在急性排斥反应的早期，病理工作公式将其分类为“A1”。在没有排斥反应的CMV感染期间，LCL目标的平均裂解率没有显著差异。本研究提供了一种功能性的体外实验，以进一步支持LTX和HLTX患者急性排斥反应的临床和组织学诊断。然后通过检测肺实质细胞的特性来探讨LTX急性排斥反应的机制。采用人气道上皮细胞系与异体淋巴细胞体外混合培养的方法模拟气道上皮细胞凋亡。在混合淋巴细胞-气道上皮细胞系（ML-AECL）中，细胞毒性淋巴细胞（CTL）未被诱导。我们发现，在AECL的刺激下，淋巴细胞分泌白介素-10。IL-2培养ML-AECL可产生CTL活性。该CTL对AECL具有mhc - i类特异性细胞毒性。提示在炎性细胞因子作用下，肺实质细胞是抗原提呈细胞的候选细胞。

This research aimed to establish the monitoring system for acute rejection in cliniacal lung and heart-lung transplantation (LTX and HLTX). For this purpose, cytotoxicity of the lymphocytes derived from the recipients were examined. Lymphocytes were isolated from bronchoalveolar lavage (BAL) and used as effector cells in standard cell-mediated lymphocytolysis (CML) assays using a series of B-lymphoblastoid cell lines (LCL) as targets. Mean percent lysis (i. e. Cytotoxicity) of LCL targets was significantly higher during acute rejection without cytomegaloviral (CMV) infection compared to no rejection or CMV infection when these targets shared one or more of the HLA class I sensitizing donor alloantigens ("class I-relevant targets"). Especially it is significantly higher in the early phase of acute rejection classified as "A1" by the pathological working formulation. There was no significant difference in mean percent lysis of LCL targets during CMV infection without rejection. This study provides a functional in vitro assay to further support the clinical and histological diagnosis of acute rejection in the LTX and HLTX patients.The properties of lung parenchymal cells were then examined to investigate the mechanisms of acute rejection in LTX.In vitro mixed culture of an immortal human airway epithelial cell line and allogeneic lymphocytes was made up to simulate the LTX.In mixed lymphocyte-airway epithelial cell line (ML-AECL), cytotoxic lymphocytes (CTL) were not elicited. We found that interleukin (IL)-10 was secreted from the lymphocytes with the stimulation of the AECL.CTL activity was generated when the ML-AECL was cultured with IL-2. This CTL showed the MHC-class I-specific cytotoxicity against the AECL.It is therefore suggested that lung parenchymal cells were candidates for antigen-presenting cells in the circumstance of inflammatory cytokines.