Enzmann V, Kaufmann A, Hollborn M, Wiedemann P, Gemsa D, Kohen L
Department of Ophthalmology, Faculty of Medicine, University of Leipzig, Germany.
Transpl Immunol. 1999 Mar;7(1):9-14. doi: 10.1016/s0966-3274(99)80013-6.
In the rejection of transplanted retinal pigment epithelium (RPE) cells, an activation of allografts is probably the pivotal point for long-term success. The detailed immunological interactions involved in the rejection after RPE transplantation are still unknown. The aim of this study is to evaluate the interactions of pro-inflammatory cytokines and chemokines in this activation process in vitro.
Human RPE cells (2 x 10(5)/ml) were therefore activated through a pre-treatment with different concentrations of interferon (IFN)-gamma (100 or 1000 U/ml), tumour necrosis factor (TNF)-alpha (1 or 10 ng/ml) or combinations of both, or employed in a nonactivated form. Afterwards, the RPE cells were tested by enzyme-linked immunosorbant assay (ELISA) and ribonuclease protection assays (RPA) for the secretion and mRNA content of the different chemokines (RANTES, MCP-1 and IL-8) and cytokines (IL-6) at various time points up to 48 h.
HRPE cells secrete the investigated cytokines in response to pro-inflammatory activation. This could be demonstrated at both the mRNA (RPA) and the protein levels (ELISA). The secretion was time and dose dependent, and significantly upregulated in comparison to that observed with nonactivated cells.
This study demonstrates that RPE cells efficiently secrete such cytokines as RANTES, MCP-1, IL-6, and IL-8, and have an accountable neutrophil and monocyte chemotactic activity. Thus, it could be indicated that the investigated cytokines play a central role in the activation cascade of RPE and in RPE rejection as well.
在移植视网膜色素上皮（RPE）细胞的排斥反应中，同种异体移植物的激活可能是长期成功的关键点。RPE移植后排斥反应中涉及的详细免疫相互作用仍不清楚。本研究的目的是在体外评估促炎细胞因子和趋化因子在这一激活过程中的相互作用。
因此，将人RPE细胞（2×10⁵/ml）用不同浓度的干扰素（IFN）-γ（100或1000 U/ml）、肿瘤坏死因子（TNF）-α（1或10 ng/ml）或两者组合进行预处理来激活，或以未激活形式使用。之后，通过酶联免疫吸附测定（ELISA）和核糖核酸酶保护测定（RPA）检测RPE细胞在长达48小时的不同时间点分泌的不同趋化因子（RANTES、MCP-1和IL-8）和细胞因子（IL-6）及其mRNA含量。
人RPE细胞在促炎激活后分泌所研究的细胞因子。这在mRNA（RPA）和蛋白质水平（ELISA）上均得到证实。分泌呈时间和剂量依赖性，与未激活细胞相比显著上调。
本研究表明，RPE细胞能有效分泌RANTES、MCP-1、IL-6和IL-8等细胞因子，并具有可计数的中性粒细胞和单核细胞趋化活性。因此，可以表明所研究的细胞因子在RPE的激活级联反应以及RPE排斥反应中均起核心作用。
