Tea Polyphenol Inhibits Allostimulation in Mixed Lymphocyte Culture

Cell Transplantation

Article

Tatsuo Kina¹  Suong-Hyu Hyon²  Jong-Yoon Kim²  Kazuaki Matsumura²  Yasuhiro Iwanaga³  Hirofumi Noguchi³ 

[1] Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606–8507, Japan;Department of Simulation Medical Engineering, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606–8507, Japan;Department of Transplantation Immunology, Kyoto University Hospital, Kyoto 606–8507, Japan;

关键词: Costimulatory signals;    Allorecognition;    Polyphenol;    EGCG;   

DOI  :  10.3727/000000007783464515

 received in 2006-06-28, accepted in 2006-10-06,  发布年份 2007

来源: Sage Journals

【 摘 要 】

Green tea polyphenols are known to protect allogenic donor tissues from acute rejection by their recipients. This immunosuppressive effect may be generated by a unique chemical property of the major component, epigallocatechin-o-gallate (EGCG), which can block specific cell surface molecules of the donor tissues. To test this hypothesis, we examined the effects of EGCG on the murine mixed lymphocyte reactions. EGCG treatment of stimulator cells significantly attenuated the proliferation of responder T cells. The proliferation did not recover upon the secondary stimulations by fresh untreated cells or exogenous IL-2. Flow cytometric analyses showed that EGCG treatment decreased the staining intensities of various cell surface molecules including MHC II, which plays a major role in antigen presentation, and B7.1, B7.2, and their ligand, CD28, which are required for costimulatory signals in T-cell activation. These results suggest that an anergic state of alloreactive T cells may be induced by either weakening of antigen signaling or blockage of costimulatory signals with EGCG. Other possible mechanisms behind the immunosuppressive effect and a potential use of EGCG treatment of donor tissues in transplantation medicine are discussed.

【 授权许可】

Unknown   
© 2007 Cognizant Comm. Corp.