Murine M phi scavenger receptor: adhesion function and expression.

In the absence of divalent cations M phi lose their spread morphology but remain adherent to tissue culture treated plastic. We have exploited this property of M phi adhesion in vitro, to isolate a rat monoclonal 2F8, which totally inhibits the divalent cation-independent adhesion of M phi to tissue culture treated plastic and is partly responsible for the trypsin-resistant adhesion of M phi to the same substratum. Immunoprecipitation from macrophages and stably transfected Chinese Hamster Ovary Cells revealed that the antigen recognised by monoclonal antibody 2F8 is identical to the murine macrophage scavenger receptor. Macrophage scavenger receptors are trimeric integral membrane glycoproteins which have been implicated in various macrophage functions including uptake of oxidised lipoprotein and the formation of foam cells in atherosclerotic lesions. We have used monoclonal antibody 2F8 to explore the expression of murine macrophage scavenger receptor in lymphoid and non-lymphoid organs of the normal adult mouse and to examine the contribution of macrophage scavenger receptor to macrophage adhesion within tissues.