Expression of the Thymosin p 4 Gene During Differentiation of Hematopoietic Cells

Thymosin 8, (TB,) was originally isolated as a thymic hormone. Its functional properties remain obscure; however, the N-terminal peptidic sequence could have a regulatory function on hematopoietic stem cell proliferation. To investigate the mechanism of TB, expression, we studied TB, gene expression in various leukemic cells and in established cell lines. Among leukemic cell samples obtained from leukemia patients, the TO, gene was highly expressed in a lymphoid lineage, especially in adult T-cell leukemia (ATL) cells, rather than in a granulocyte lineage. The TB, gene was more transcriptionally active in chronic B-cell leukemia than in acute B-cell leukemia, while it was inactive in plasma cell leukemia. We also found that cells