Terminal Deoxynucleotidyl Transferase in type B Acute Lymphoblastic Leukemia.

Abstract

Terminal deoxynucleotidyl transferase (TdT or DNTT) is a nuclear enzyme whose expression is restricted to normal tissue (thymus and bone marrow) and to lymphoid precursors of the B and T cell. TdT catalyzes the addition of deoxynucleotides independently of the template in the 3¿-terminal hydroxyl end of the oligonucleotide primers. In addition, it plays a crucial role in the insertion of N regions during the rearrangement of immunoglobulin genes and receptor T and B cells (TCR and BCR) at the DJ binding sites and variable (V) diversity (D) binding (J). This mechanism of the diversity of the binding is essential for the development of a repertoire of immunoglobulin¿s and B and T cell receptors.