Receptors for unopsonized particles: the role of alveolar macrophage scavenger receptors

• Published in: Current molecular medicine Vol. 1; no. 5; p. 589
• Main Authors: Palecanda, A, Kobzik, L
• Format: Journal Article
• Language: English
• Published: Netherlands 01-11-2001
• Subjects: Animals; Antigens, CD - physiology; Asialoglycoprotein Receptor; CD18 Antigens - physiology; CD48 Antigen; Cricetinae; Flow Cytometry; Humans; In Vitro Techniques; Lectins, C-Type; Macrophages, Alveolar - physiology; Mannose-Binding Lectins; Membrane Proteins; Mice; Receptors, Cell Surface - physiology; Receptors, Immunologic - classification; Receptors, Immunologic - physiology; Receptors, Lipoprotein; Receptors, Scavenger; Receptors, Vitronectin - physiology; Scavenger Receptors, Class B
• ISSN: 1566-5240
• DOI: 10.2174/1566524013363384

The lung is constantly exposed to potentially pathogenic particles and microorganisms. Alveolar macrophage (AM) binding of inhaled environmental particles is a critical first step in phagocytosis and clearance, and must be accomplished without the benefit of opsonization by specific antibodies. Opsonin-independent phagocytosis is initiated by direct recognition of phagocytic target. The identities of receptors on AMs that mediate unopsonized particle binding were, until recently, not known. Using flow cytometry, monoclonal antibody and expression cloning techniques we have found a major role for the scavenger receptor, MARCO in AM binding of particles and bacteria. In this review we will discuss the role of scavenger receptors in AM binding of unopsonized particles and the use of flow cytomety in analyzing AM-particle interaction. We will also discuss other non-scavenger receptors involved in opsonin-independent phagocytosis.