title: [Over-expression of CCL21 up-regulates the antigen presentation-related genes of CK8/18 positive thymic epithelial cells in patients with myasthenia gravis].
abstract: OBJECTIVE
  To identify the distribution of chemokine (C-C motif) ligand 21 (CCL21) in the thymus of patients with myasthenia gravis (MG) and explore the effects of up-regulation of CCL21 on the expressions of antigen presentation-related genes in cytokeratin 8/18 (CK8/18) positive thymic epithelial cells (TECs) after transfected with CCL21 genes.
  
  
  METHODS
  The expressions and distributions of CK8/18 and CCL21 in the thymus tissue of MG patients were detected by immunohistochemistry. The mRNA levels of CCL21, CCL19 and their receptor chemokine (C-C motif) receptor 7 (CCR7) in the thymus tissue of MG patients were determined by real-time quantitative PCR (qRT-PCR). Primary cultured CK8/18⁺ TECs were transfected with pCMV-CCL21, and the relative mRNA expressions of function-associated genes (CD80, ICAM-1, CD86, HLA-DR, HLA-A) in CK8/18⁺ TECs before and after the transfection were investigated by qRT-PCR.
  
  
  RESULTS
  Immunohistochemical results showed that the number of CK8/18 positive cells in the hyperplastic thymus tissues of MG patients was significantly more than that in the normal controls, and the protein expression of CCL21 was also much higher in the hyperplastic thymus tissues. The qRT-PCR showed that the expressions of CCL21 and CCR7 mRNA increased significantly in hyperplastic thymus tissues of MG patients compared with those in normal controls, while there was no difference in the expression of CCL19. Furthermore, CK8/18 positive cells were found mainly located in cortico-medullary junction and medulla area. The relative mRNA expression levels of HLA-A, HLA-DR, ICAM and CD80 rose significantly in CK8/18⁺ TECs after transfected with pCMV-CCL21.
  
  
  CONCLUSIONS
  The over-expression of CCL21 could increased the expressions of antigen presentation-related genes in CK8/18⁺ TECs in MG patients.
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiac Surgery, Seventh People's Hospital of Zhengzhou City, Zhengzhou 450016, China.
authors.forename: Juntao
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Zhengkun
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Pharmacy, Zhengzhou Municipal Central Hospital, Zhengzhou University, Zhengzhou 450007, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Yin
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Xuan
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Qianru
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: DU
mesh_terms: D000293:Adolescent; D000328:Adult; D017951:Antigen Presentation / Q000235:genetics*; D018122:B7-1 Antigen / Q000235:genetics; D054421:Chemokine CCL21 / Q000235:genetics*; D002648:Child; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D015234:HLA-A Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics; D006801:Humans; D053538:Keratin-18 / Q000378:metabolism; D053533:Keratin-8 / Q000378:metabolism; D008297:Male; D009157:Myasthenia Gravis / Q000235:genetics* / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D054400:Receptors, CCR7 / Q000235:genetics; D013950:Thymus Gland / Q000276:immunology*; D014162:Transfection; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D018122:B7-1 Antigen; C515370:CCR7 protein, human; D054421:Chemokine CCL21; D015234:HLA-A Antigens; D006684:HLA-DR Antigens; D053538:Keratin-18; D053533:Keratin-8; D012333:RNA, Messenger; D054400:Receptors, CCR7