HLA-G in the human placenta: expression and potential functions

HLA-G is a non-classical class I molecule specifically expressed in the pla centa, suggesting that it might have a physiological function at the matern o-foetal interface. The structural characteristics of HLA-G, the placental pattern of expression and the functional properties of this class Ib glycop rotein in vitro are described and evaluated in the context of pregnancy. Th e possible anti-viral function of HLA-G, its modulatory role of natural kil ler cell activity and its likely nonimmunological functions are discussed.