November, 2010 -- Researchers at RTC have recently identified a new immune cell. The new immune cell, named CD8+AT2R+ T cell, mediates protective actions against inflammation-induced heart damage.
The research, led by Dr. Jun Li, a group leader at RTC was published in The Journal of Immunology in the November 15th issue and is among the top 10% of findings published in the journal (featured in ‘In This Issue’). The neurohormone angiotensin II induces vasoconstriction and increased blood salt levels mainly via AT1 receptor (R); thus AT1R blockers are used clinically to treat high blood pressure and cardiac failure. Less is known about the functions of AT2R. In recent years, however, there has been growing evidence that increased levels of AT2R in the heart correlate with cardioprotection following acute myocardial infarction (MI). To better understand the role of AT2R, Dr. Jun Li and his colleagues discovered the CD8+AT2R+ T cells and studied their functional role following acute MI. Seven days after MI, the numbers of CD8+AT2R+ T cells were increased significantly in the hearts and spleens of MI rats, compared with sham-operated rats. Unlike CD8+AT2R- T cells, postinfarct CD8+AT2R+ T cells did not exhibit cytotoxicity toward cardiomyocytes in coculture and were instead found to secrete cardioprotective IL-10 in response to AT2R-mediated stimulation. In vivo treatment of rats with an AT2R agonist, compound 21, was found to increase the numbers of IL-10–expressing CD8+AT2R+ T cells in the infarcted myocardium relative to untreated rats. Furthermore, the transplantation of postinfarct splenic CD8+AT2R+ T cells into rats immediately following MI significantly reduced the infarct size, compared with rats that had received CD8+AT2R- T cells. As CD8+AT2R+ T cells were also found in healthy human donors, these results have important implications for AT2R-based clinical treatments of acute MI. The discovery of CD8+AT2R+ T cell allows the researchers at RTC to further define the orchestration of neurohormore and immune cell and to open completely new avenues for future cell therapy in treating patients with inflammatory organ damage including acute heart attack.
The article entitled “Identification of Noncytotoxic and IL-10–Producing CD8+AT2R+ T Cell Population in Response to Ischemic Heart Injury” can be found on The Journal of Immunology web site http://www.jimmunol.org/.
Publikation: Curato C, Slavic S, Dong J, Skorska A, Altarche-Xifró W, Miteva K, Kaschina E, Thiel A, Imboden H, Wang J, Steckelings U, Steinhoff G, Unger T, Li J. Identification of non-cytotoxic and IL-10-producing CD8+AT2R+ T cell population in response to ischemic heart injury. J Immunol. 2010;185:6286-6293
