GENERATION OF AN ANTIBODY TO HLA-G IN TRANSGENIC MICE AND DEMONSTRATION OF THE TISSUE REACTIVITY OF THIS ANTIBODY

A method was devised to generate antibodies against the non-classical class I HLA-G antigen. This consisted of immunising HLA-A2/beta(2)m double transgenic mice with HLA-G transfected into mouse Ltk(-) cells. A polyclonal antibody was obtained which appears to be specific for HLA-G. The staining pattern of this antibody was restricted solely to all populations of extravillous trophoblast. No fetal tissues reacted with this antibody, including those where HLA-G mRNA has been demonstrated, such as fetal eye, thymus and liver. This study confirms that HLA-G is a trophoblast-specific protein, although it remains a possibility that the technique of immunohistology is not sufficiently sensitive to detect low level HLA-G antigen expression in non-trophoblast tissues.