Investigations of the scavenger receptor class A and complement receptor 3 - Two pattern recognition receptors

Abstract

One of the fundamental aspects of innate immunity is the ability of immune cells, particularly antigen-presenting cells (APCs) such as macrophages and dendritic cells(DCs), to detect and respond to potential microbial pathogens or even endogeneous molecules that have become altered and pose a threat to the system. These cells employ an array of pattern recognition receptors (PRRs) that can recognize these pathogens or altered endogeneous molecules either directly by binding to pathogen associated molecular patterns (PAMPs) found on the microbial cell surfaces or indirectly via opsonins such as complement components and immunoglobulins which have deposited on the surfaces of cellular or molecular targets. In this study, we focused on two major PRRs found on APCs, the opsonic complement receptor 3 (CR3) and non-opsonic scavenger receptor class A (SR-A). We will attempt to investigate certain aspects of their ligand binding properties and delineate downstream signaling pathways upon ligand engagement.