HLA-G expression is induced in Epstein-Barr virus-transformed B-cell lines by culture conditions

Human leukocyte antigen-G (HLA-G) belongs to the nonclassical HLA class I family of genes presently designated as class Ib genes. It was found to be expressed mainly in placental tissue and in the thymus. Expression of HLA-G is induced by lymphokines such as interleukin-10 and has been associated with the escape of tumor cells from immune surveillance or with inhibition of graft rejection. In this report, Epstein-Barr virus-transformed B-cell lines established from peripheral blood lymphocytes from healthy volunteers were studied. Our results show that EBV-transformed B-cell lines, but not freshly separated peripheral blood lymphocytes, can be induced to express HLA-G either by subjecting the cultures to nutrient deficiency to hypoxia or to both, however, not all cell lines responded equally to stress conditions. The association of HLA-G with certain cancer transformations may suggest that the resistance to HLA-G expression could be related to susceptibility to the development of malignancy.