Anemia Research Today is a free monthly online journal that collates and summarizes the latest research about Anemia, including details on symptoms, diagnosis, diet, treatment, causes.

T-bet, a Th1 transcription factor, is up-regulated in T cells from patients with aplastic anemia.

Solomou EE, Keyvanfar K, Young NS

Hematology Branch, National Heart, Lung, and Blood Institute/NIH, Bldg 10, CRC, Rm 3E5216, 10 Center Drive, Bethesda, MD 20892, USA. solomoue@nhlbi.nih.gov

In aplastic anemia, immune destruction of hematopoietic cells results in bone marrow failure. Type 1 cytokines, especially IFN-gamma, have been implicated in the pathophysiology of T-cell-mediated, Fas-mediated stem cell apoptosis of hematopoietic cells. Here, we show that the transcription factor T-bet (T-box expressed in T cells) is increased in T cells from patients with aplastic anemia. Patients' T-bet bound directly to the proximal site of the IFN-gamma promoter without any prior stimulation, in contrast to healthy controls. Increased levels of Itk kinase participated in T-bet up-regulation and active transcription of the IFN-gamma gene observed in these patients. Blocking PKC-, a kinase that lies downstream of Itk kinase, decreased T-bet protein and IFN-gamma intracellular levels. These data suggest that the increased IFN-gamma levels observed in aplastic anemia patients are the result of active transcription of the IFN-gamma gene by T-bet. Blocking the transcription of the IFN-gamma gene with kinase inhibitors might lead to the development of novel therapeutic agents for patients with aplastic anemia and other autoimmune diseases.

Published 4 May 2006 in Blood, 107(10): 3983-91.
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