Regulation of MHC class II expression in human T-cell malignancies

An epigenetic silencing mechanism has been implicated in leukaemia of T-cells of the immune system.

Major Histocompatability Complex (MHC) class II proteins are an important part of the defense mechanism of the immune response, and are often lacking in tumorous cells. These MHC class II proteins require a transactivator, encoded by a gene called MHC2TA.

A promoter region upstream of this gene regulates production of the transactivator, and has been shown to be hypermethylated in leukaemic T-cells. Demethylating the DNA of these cells resulted in a re-expression of MHC class II defense antigens. This implies an important role for epigenetic factors in leukaemic T-cells.

Carl Morrow