内源性 CRF 对小鼠肠系膜淋巴结树突状细胞的生物表型的影响

Effects of the endogenous CRF on the biological phenotypes of mouse mesenteric lymph nodes den-dritic cells

目的：检测小鼠肠系膜淋巴结树突状细胞（ MLNDC）上促肾上腺皮质激素释放因子（CRF）及其受体CRFR1、CRFR2的表达，探讨CRF及其受体对MLNDC的表型改变的影响。方法采用磁珠分选技术分离C57BL／6小鼠的MLNDC，以流式标记CD11c鉴定DC分选纯度，获得高纯度MLNDC后，RT-PCR检测其CRF、CRFR1与CRFR2的转录水平，免疫荧光双染法明确MLNDC表面CRFR1及CRFR2的表达。将MLNDC体外培养，予以CRF受体相应拮抗剂干预，流式细胞术观察DC表面分子变化。结果流式细胞术检测显示经磁珠分选后， CD11 c标记的树突状细胞阳性率为（80．12±6．34）％，锥虫蓝染色显示细胞活性＞90％，MLNDC存在CRF、CRFR1与CRFR2 mRNA的表达，免疫荧光提示其表面存在CRFR1及CRFR2的表达，CRFR1拮抗剂Antalarmin（10 nmol／L）可以下调MLNDC表面共刺激分子CD86，而CRFR2拮抗剂Astressin 2B（10 nmol／L）可以上调MLNDC表面共刺激分子CD86。结论体外分离的C57 BL／6小鼠MLNDC自身存在CRF 及其受体CRFR1和CRFR2的表达，并且该两种受体对MLNDC表型具有相反的作用。

Objective To investigate the expression of corticotropin-releasing factor （CRF） and its receptors including CRFR1 and CRFR2 on mouse mesenteric lymph nodes dendritic cells （MLNDC）, and to analyze their effects on the biological phenotypes of intestinal dendritic cells .Methods The MLNDCs were isolated from C57BL/6 mice by using magnetic bead sorting .The purity of CD11c^＋DCs was identified by flow cytometry .The double-labeling immunofluorescence and the reverse transcriptase-polymerase chain reaction （RT-PCR） were performed to detect the expression of CRF , CRFR1 and CRFR2 on MLNDCs.The MLNDCs were exposed to CRF with or without the interference of CRFR 1 and CRFR2 antagonists .Flow cy-tometry was used to measure the changes of surface molecules （ MHCⅠ and MHCⅡ） and co-stimulatory molecules （CD80 and CD86）.Results The CD11c^＋DCs accounted for （80.12±6.34）% of the isolate cells with a high cell viability of more than 90%.The expression of CRF , CRFR1 and CRFR2 at mRNA lev-el were detected in MLNDCs by RT-PCR.Results of the immunofluorescent staining assay indicated that both CRFR1 and CRFR2 were expressed on the surface of MLNDCs .The expression of CD86 on MLNDCs was inhibited by the treatment of MLNDCs with CRFR 1 antagonist , but enhanced by the treatment with CRFR2 antagonist .Conclusion Both CRF and CRFRs were detected in the MLNDCs isolated from the C57BL/6 mice.The CRF could alter the biological phenotypes of MLNDCs through binding to different CRFRs （CRFR1 and CRFR2）, which affected the phenotypes of MLNDCs in opposite ways .