[Frontiers in Bioscience 17, 1648-1658, January 1, 2012]

Cross-reactivity of autoreactive T cells with MBP and viral antigens in patients with MS

Weizhi Cheng1, Yanhui Ma1, Fang Gong1, Chaoying Hu1, Liu Qian1, Qiuyu Huang1, Qiwen Yu1, Jiying Zhang1, Shengdi Chen2, Zhengguo Liu3, Xuehua Chen2, Tong Zhou2, Dongqing Zhang1

1Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, 227 South Chongqing Road, Shanghai 200025, China, 2Shanghai JiaoTong University School of Medicine, Ruijin Hospital, 197 Ruijin Er road, Shanghai 200025, China, 3Shanghai JiaoTong University School of Medicine, Xinhua Hospital, 1669 Kongjiang Road, Shanghai 200092, China


1. Abstract
2. Introduction
3. Materials and methods
3.1. Patients and specimens
3.2. Reagents and peptides
3.3. HLA genotyping
3.4. Detection of HHV-6 DNA in serum and cell-free CSF
3.5. Determination of BV gene usage in CSF and in blood T cells by real-time PCR analysis
3.6. Quantitative measurement of MBP
3.7. The detection of HHV-6 IgG antibody
3.8. Epstein-barr virus VCA IgM (mu)-capture ELISA
3.9. Epstein-barr virus EBNA-1/ VCA IgG ELISA
3.10. Precursor frequency analysis of CD4+/CD8+ T cells recognizing MBP and HHV-6 peptides
3.11. Estimation of the frequency of specific T cells
3.12. The reactivity pattern of resulting T cell lines
3.13. Cytotoxic activity was measured in a standard 51Cr-release assay
3.14. The phenotypic expression of the representative CD8+ cross-reactive T cell lines
4. Results
4.1. Characteristics of cell-free serum/CSF HHV-6 DNA and HLA-DR genotypes in Chinese MS patients
4.2. The association between anti-HHV-6/EBV antibody and MBP in Chinese MS patients
4.3. Cross-reactivity of CD4+/CD8+ autoreactive T cells between HHV-6 and MBP
4.4. The reactivity pattern and TCR V gene usage of cross-reactive T cells
4.5. Cross-reactivity of CD8+ cytotoxic T cells between HHV-6 and MBP
4.6. Phenotypes of the representative cross-reactive CD8+T cell lines
5. Discussion
6. Acknowledgements
7. References


In this study, we detected the viral DNA of Human Herpes Virus 6 (HHV-6) in the sera and cell-free cerebrospinal fluid (CSF) of Chinese multiple sclerosis (MS) patients. The results revealed that the copy numbers of serum HHV-6 viral DNA were higher in MS than in normal subjects (NS) or in other neurologic diseases (OND). We also found that in the MS subjects, most T cells recognizing myelin basic protein (MBP) were cross-reactive and could be activated by a synthetic peptide corresponding to residues of HHV-6 or EBV. The estimated precursor frequency of these cross-reactive T cells recognizing both peptides, MBP and HHV-6 or EBV, was significantly elevated in MS compared with that in controls. More significant was the presence of CD8+ cytotoxic cross-reactive T cells, as they could directly induce injury to oligodendrocytes that are known to express both MBP and MHC class I molecules. The study provides important evidence for understanding the potential role of HHV-6 or EBV infection in the pathogenesis of MS.