Study On The Regulation Of B7 Molecule Expression On Primary Acute Leukemic Cells And Gene Transfer

Objective: It is a central role in the regulation of the T cell immune response that the costimulatory molecules, such as B7 molecules that contain B7-1 and B7-2, interact with CD28 expressed on the surface of T cell. One of mechanisms that have been implicated for the escape of tumor cells from immune surveillances is the lack expression of B7 molecules by the most of the tumor cells. Intense research has shown that B7 molecules are usually absent or expressed at low intensity on acute leukemic cells. B7-1-transduced acute myeloid leukemia (AML) cells and B7-1-transduced acute lymphocytic leukemia (ALL) cells can provide the high expression of B7-1 on the transduced cells ex vivo. The vaccines of B7-1-transduced acute leukemia (AL) cells result in long-lasting T cells immunity against subsequent challenge with wild-type leukemic cells in animal models. Thus, the gene transfer of B7 molecules is the important pathway of enhancing the immunogenicity of leukemic cells. Further studies have to focus on enhancing of transfer efficiency of gene and searching for the new vector used to B7-1 and B7-2 gene transfer for leukemic cells.