Transfection,overexpression and clinical application of human 60 kDa Ro/SSA autoantigens in HEp-2 cells  

作　　者：吕良敬 陈顺乐 顾越英 沈南 鲍春德 王元 薛峰 叶萍 俞翀曌 

机构地区：[1]Shanghai Rheumatology Institute, and Department of Rheumatology, Renji Hospital of Shanghai Second Medical University, Shanghai 200001, China

出　　处：《Chinese Medical Journal》2003年第3期31-34,共4页中华医学杂志（英文版）

基　　金：ThisstudywassupportedbyShanghaiScienceCommitteeFoundationofChina (No 9844 190 73 )

摘　　要：Objective To develop an improved substrate for indirect immunofluorescence test (IIF) for detecting anti-Ro60/Sjogren's syndrome A (Ro/SSA) autoantibodies.Methods 60-kDa Ro/SSA autoantigens (Ro60) cDNAs were obtained from human placental cDNA library using polymerase chain reaction (PCR) and were cloned into the mammalian expression vector-pEGFP-C1. Then, the recombinant plasmids were transfected into HEp-2 cells. We confirmed the overexpression, localization and antigenicity of fusion proteins in transfected cells by means of immunoblotting, confocal fluorescence microscopy and IIF. HEp-2 and HEp-Ro60 were analyzed by IIF using a panel of 10 precipitin-positive anti-Ro human sera simultaneously.Results Stable expression of Ro60-green fluorescent protein (Ro60-GFP) fusion proteins were maintained ten more generations. Ro60-GFP kept the antigenicity of Ro while demonstrating its own characteristic immunofluorescent pattern in HEp-Ro60 cells. The transfectants dramatically increased the sensitivity of IIF testing (a mean increase of 6.7-fold in endpoint titer). Eight overten (8/10) positive anti-Ro sera showed characteristic immunofluorescent patterns for HEp-Ro60, including two sera that were anti-nuclear antibodies (ANA) negative for untransfected HEp-2. IIF-ANA in all healthy sera was negative for HEp-Ro60. Conclusions As a new substrate for IIF, the Ro60 transfectants can be used to detect anti-Ro antibodies. In addition, transfected HEp-2 cells keep the immunofluorescent properties of HEp-2 cells in IIF-ANA tests and can be employed as a substrate for routine IIF-ANA detection.Objective To develop an improved substrate for indirect immunofluorescence test (IIF) for detecting anti-Ro60/Sjogren's syndrome A (Ro/SSA) autoantibodies.Methods 60-kDa Ro/SSA autoantigens (Ro60) cDNAs were obtained from human placental cDNA library using polymerase chain reaction (PCR) and were cloned into the mammalian expression vector-pEGFP-C1. Then, the recombinant plasmids were transfected into HEp-2 cells. We confirmed the overexpression, localization and antigenicity of fusion proteins in transfected cells by means of immunoblotting, confocal fluorescence microscopy and IIF. HEp-2 and HEp-Ro60 were analyzed by IIF using a panel of 10 precipitin-positive anti-Ro human sera simultaneously.Results Stable expression of Ro60-green fluorescent protein (Ro60-GFP) fusion proteins were maintained ten more generations. Ro60-GFP kept the antigenicity of Ro while demonstrating its own characteristic immunofluorescent pattern in HEp-Ro60 cells. The transfectants dramatically increased the sensitivity of IIF testing (a mean increase of 6.7-fold in endpoint titer). Eight overten (8/10) positive anti-Ro sera showed characteristic immunofluorescent patterns for HEp-Ro60, including two sera that were anti-nuclear antibodies (ANA) negative for untransfected HEp-2. IIF-ANA in all healthy sera was negative for HEp-Ro60. Conclusions As a new substrate for IIF, the Ro60 transfectants can be used to detect anti-Ro antibodies. In addition, transfected HEp-2 cells keep the immunofluorescent properties of HEp-2 cells in IIF-ANA tests and can be employed as a substrate for routine IIF-ANA detection.

关 键 词：Ro60/Sjogren's syndrome A TRANSFECTION HEp-2 cell 

分 类 号：R446.6[医药卫生—诊断学]