Differential tissue expression of epitopes of the tetraspanin CD151 recognised by monoclonal antibodies

CD151, a member of the tetraspanin family of cell membrane proteins, is wid ely expressed in epithelial, endothelial and muscle cells as well as platel ets and megakaryocytes. Several monoclonal antibodies recognising CD151 in transfected cells and immunoprecipitating typical bands of 28 and 32 kDa fr om cell lysates have been produced. Surprisingly, these antibodies show dif ferent patterns of staining on tissue sections and on haemopoietic cells. H ere we show that these differences are at least in part due to masking of c ertain epitopes in integrin/CD151 complexes. These data have have important implications for the use of monoclonal antibodies in studies a. of the dis tribution and function of CD151. Of six monoclonal antibodies from four lab oratories, 11B1 was found to be the most reliable for detection of CD151 in different cell and tissue contexts.