Mannose receptor and scavenger receptor: two macrophage pattern recognition receptors with diverse functions in tissue homeostasis and host defense.

In this report we have reviewed our recent data which suggest a new function for MR in antigen delivery in lymphoid organs, together with highlighting three recent discoveries from our laboratory concerning the role of SR-A in adhesion, phagocytosis of apoptotic cells and protection from endotoxic shock in mice. The diversity of functions mediated by each receptor demonstrates there is much yet to be discovered about how macrophages use their cell surface receptors to 'see' the external environment, and yet perform a wide range of strictly regulated functions.