RESEARCH ON HUMAN AIRWAY EPITHELIUM ACTING AS ALLOANTIGEN-PRESENTING CELLS

在肺移植中，循环中的白细胞和血管内皮细胞被认为是抗原提呈细胞(APC)。在本研究中，我们首先确定了呼吸道上皮细胞是否具有APC的功能。将BEAS-2B(B2B，1×10^5个/ml)不朽的人上皮细胞株BEAS-2B(B2B，1×10^5个/ml)与其表面的共刺激分子ICAM-1、LFA-3和B7一起结构性地表达HLAI类和II类抗原，并将其转移到来自健康志愿者的同种异体人外周血淋巴细胞(PBL)的10ml完全培养液中(1*10^6个/ml)。混合淋巴细胞-上皮细胞系(ML-AECL)培养3d，收获。另设单向混合淋巴细胞培养(MLC)作为对照研究。用EASIA法测定上清液中IL-10的浓度。MLC组IL-10浓度未见明显升高(正负11.8pg/ml，N=5)，但显著降低…。更多的是ML-AECL(128pg/ml，N=5，p=0.043)。B2B刺激诱导同种异体淋巴细胞群增殖并分泌IL-10。据报道，Th2是辅助性T细胞的一个亚群，它分泌IL-10，而IL-10反过来抑制Th1和细胞毒性T细胞(CTL)的增殖和激活。其次，我们研究了共刺激分子在B2B中的作用。B2B用抗HLAI类、抗HLAII类、抗ICAM-1、抗LFA-3或抗B7单抗处理B2B，然后培养ML-AECL并收获。采用四甲基偶氮唑蓝(四甲基偶氮唑蓝)法检测细胞增殖。掩蔽B2B细胞表面的HLAI、II类或LFA-3后，MTT值(相对于对照组的百分比)明显低于对照组。在B2B细胞和同种异体淋巴细胞的混合培养中，淋巴细胞识别BEAS-2B上表达的MHC-I和II类抗原，BEAS-2B上的LFA-3也有助于激活淋巴细胞的同种异体反应。较少

In lung allotransplantation, circulating leukocytes and vascular endothelial cells have been considered to be antigen-presenting cells (APCs). First in this research, we determined whether airway epithelial cells function as APCs.An immortal human epithelial cell line, BEAS-2B (B2B,1*10^5 cells/ml), which constitutively expresses both HLA-class I and class II antigens along with costimulatory molecules, ICAM-1, LFA-3, and B7 on its surface, was irradiated (50Gy) and transferred to 10ml of complete culture medium with allogeneic human peripheral blood lymphocyte (PBL) (1*10^6 cells/ml) from a healthy volunteer. The mixed lymphocyte-epithelial cell line culture (ML-AECL) was then incubated for 3 days, and harvested. As a control study, a one-way mixed lymphocyte culture (MLC) was also made up. Concentration of interleukin (IL) -10 in each supeynatant were assayd using an EASIA method. The concentration of IL-10 was not elevatedin MLC (9.3<plus-minus>11.8pg/ml, N=5) but significantly elev … More atedin ML-AECL (128<plus-minus>110pg/ml, N=5, p=0.043). Stimulation of B2B induceda population of allogeneic lymphocytes to proliferate and secrete IL-10. It has been reported that Th2, a subset of helper-T cells, secretes IL-10, which in turn inhibits both Th1 and cytotoxic T cells (CTLs) from proliferating and becoming active. We suggest that airway epithelial cells stimulate Th2, and, as a result, may play a role is suppressiing the allospecific reaction in acute rejection.Second, we investigated the role of costimulatory molecules on B2B.B2B were pretreated with either anti-HLA class I,anti-HLA class II,anti : ICAM-1, anti-LFA-3, or anti-B7 monoclonal antibody, Then the ML-AECL culture was then incubated, and harvested. Cell proliferation assay was performed using the colorimetric (MTT) assay. The MTT indeces (percentages relative to the control) were found to be significantly lower than the control when HLA class I,class II or LFA-3 on B2B was masked. In mixed culture consisting of B2B cells as stimulators and allogeneic lymphocytes, the lymphocytes recognized MHC-class I and II antigens expressed on the BEAS-2B.LFA-3 on BEAS-2B also contributed to the activation of lymphocyte alloreactivity. Less