Li Y, Li N, Li Y, Wu B, Li J
Research Institute of General Surgery, Nanjing Military Area General Hospital of PLA, Nanjing 210002, China.
Chin Med J (Engl). 2001 Oct;114(10):1089-94.
To investigate the kinetics and the magnitude of intragraft gene expression of interleukin-2 (IL-2), interferon-gamma (IFN-gamma), perforin and granzyme B, and intragraft expression of interleukin-2 receptor (IL-2R) and intercellular adhesion molecule-1 (ICAM-1) during acute rejection episodes, and to analyze the changes in apoptosis in small intestinal allograft rejection.
Heterotopic small intestine transplantation was performed with inbred rats F344/N (RT1l) and Wistar/A (RT1-Ak, RT1-Ed). All recipients were divided into four groups: group 1: Wistar, native control; group 2: Wistar-->Wistar; group 3: F344-->Wistar and group 4: F344-->Wistar + cyclosporine A (6 mg.kg-1.d-1 i.m.). The grafts were harvested on postoperative days (PODs) 3, 5 and 7. All samples were examined pathologically. Intragraft mRNA expression of IL-2, IFN-gamma, perforin and granzyme B were detected with reverse transcriptase polymerase chain reaction (RT-PCR) and intragraft expression of IL-2R and ICAM-1 were stained using immunohistochemistry. We also analyzed the change in apoptosis rejection with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).
Mild acute rejection occurred on POD 3 in the allograft group, moderate acute rejection on POD 5, and severe acute rejection on POD 7, while none of the isografts had histological evidence of acute rejection. Cyclosporine A could effectively control rejection. Gene expression was virtually negative in the native control. Only on POD 5 was IL-2 mRNA expression of allografts significantly higher than that of isografts (P < 0.05). IFN-gamma mRNA expression was significantly higher than that of the control groups (P < 0.01) on PODs 3, 5 and 7, and the level of perforin and granzyme B mRNA expression reached significantly higher levels than in the other two control groups on POD 5 and POD 7. Intragraft IL-2R expression of the allograft was significantly higher than that of the other three control groups. Only on POD 3 was intragraft ICAM-1 expression of allografts significantly higher than isografts. The number of apoptotic cells per crypt of allografts was significantly higher than that of the other three control groups on POD 3 and POD 5 (P < 0.01).
Transcription of IL-2, IFN-gamma, perforin and granzyme B, and expression of IL-2R and ICAM-1 as well as apoptosis of epithelial cells of the grafts play an important role in small intestine allograft rejection. Intragraft gene expression of IFN-gamma and intragraft expression of IL-2R as well as apoptotic epithelial cells may become a specific and sensitive diagnostic method of clinical value. Furthermore, therapeutic strategies to alter these molecules in small intestine transplantation may improve the outcome of current antirejection therapy.
研究急性排斥反应期间移植物中白细胞介素-2（IL-2）、干扰素-γ（IFN-γ）、穿孔素和颗粒酶B的基因表达动力学及表达量，以及白细胞介素-2受体（IL-2R）和细胞间黏附分子-1（ICAM-1）的移植物内表达，并分析小肠同种异体移植排斥反应中细胞凋亡的变化。
采用近交系大鼠F344/N（RT1l）和Wistar/A（RT1-Ak，RT1-Ed）进行异位小肠移植。所有受体分为四组：第1组：Wistar，自体对照；第2组：Wistar→Wistar；第3组：F344→Wistar；第4组：F344→Wistar + 环孢素A（6 mg·kg-1·d-1，肌肉注射）。在术后第3、5和7天采集移植物。所有样本进行病理检查。采用逆转录聚合酶链反应（RT-PCR）检测移植物中IL-2、IFN-γ、穿孔素和颗粒酶B的mRNA表达，采用免疫组织化学法检测移植物中IL-2R和ICAM-1的表达。我们还采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）分析排斥反应中细胞凋亡的变化。
同种异体移植组在术后第3天发生轻度急性排斥反应，第5天发生中度急性排斥反应，第7天发生重度急性排斥反应，而异种同基因移植组均无急性排斥反应的组织学证据。环孢素A可有效控制排斥反应。自体对照组基因表达几乎为阴性。仅在术后第5天，同种异体移植物的IL-2 mRNA表达显著高于异种同基因移植物（P < 0.05）。术后第3、5和7天，IFN-γ mRNA表达显著高于对照组（P < 0.01），穿孔素和颗粒酶B mRNA表达水平在术后第5天和第7天显著高于其他两个对照组。同种异体移植物的移植物内IL-2R表达显著高于其他三个对照组。仅在术后第3天，同种异体移植物的移植物内ICAM-1表达显著高于异种同基因移植物。术后第3天和第5天，同种异体移植物每个隐窝的凋亡细胞数显著高于其他三个对照组（P < 0.01）。
IL-2、IFN-γ、穿孔素和颗粒酶B的转录，以及IL-2R和ICAM-1的表达以及移植物上皮细胞的凋亡在小肠同种异体移植排斥反应中起重要作用。移植物内IFN-γ基因表达、移植物内IL-2R表达以及凋亡上皮细胞可能成为具有临床价值的特异性和敏感性诊断方法。此外，在小肠移植中改变这些分子的治疗策略可能改善当前抗排斥治疗的效果。
