Terminal Deoxynucleotidyl Transferase (TdT) Inhibition of Cord Blood Derived B and T Cells Expansion

Introduction Terminal deoxynucleotidyl transferase (TdT) is a nuclear enzyme in one unique parcel of the pol X family of DNA polymerase.1,2 In human, TdT activity is present in the immature fraction of thymocytes and bone marrow cells.3,4 TdT plays a vital role in the development and variation of the immune system in vertebrates.5-7 TdT contributes to the variation of antigen receptors by random addition of nucleotides to single-stranded DNA at the junctions recombination of immunoglobulin heavy-chain genes in B and T cells development.8-11 V(D)J recombination creates diversity of antigen receptors in immune system.12 TdT is responsible for inserting nucleotides to the junctions of gene segment during V (D) J recombination.13-15 TdT gene is present in pre-B and pre-T cells and increases in some human leukemia's.9,16 For this reason, TdT is an effective biochemical marker for classifying leukemia's.17 TdT has been identified in childhood and adult acute lymphoblastic leukemia (ALL) and often appear in chronic myelogeneos leukemia (CML), acute nonlymphocytic leukemia (ANLL) and acute myeloid leukemia (AML). [...]it could probably be applicable in combination of TdT inhibition for leukemia treatment. The aim of this study is to evaluate TdT expression in cord blood mononuclear cells using different key immune cell cytokines like IL-2, IL7, and IL15. [...]it is to indicate the influence of TdT inhibition by genistin on the generation of B and T cells. [...]TdT is a factor that interacts and influenced by cytokines, and also could effect on the rate of apoptosis and proliferation to balance B and T cell development.