MARCO, an innate activation marker of macrophages, is a class A scavenger receptor for Neisseria meningitidis

S Mukhopadhyay, Y Chen, M Sankala… - European journal of …, 2006 - Wiley Online Library
S Mukhopadhyay, Y Chen, M Sankala, L Peiser, T Pikkarainen, G Kraal, K Tryggvason
European journal of immunology, 2006Wiley Online Library
The scavenger receptor‐AI/II (SR‐A) and macrophage receptor with collagenous domain
(MARCO) share a common domain organisation and ligand repertoire, including selected
polyanions and gram‐positive and‐negative organisms, but differ in fine specificity of ligand
binding, tissue distribution and regulation. Neisseria meningitidis (NM) is a selective ligand
for SR‐A, but there is evidence for an additional SR‐A‐independent, polyanion‐sensitive
component for NM recognition. We therefore studied the relative contribution of MARCO and …
Abstract
The scavenger receptor‐A I/II (SR‐A) and macrophage receptor with collagenous domain (MARCO) share a common domain organisation and ligand repertoire, including selected polyanions and gram‐positive and ‐negative organisms, but differ in fine specificity of ligand binding, tissue distribution and regulation. Neisseria meningitidis (NM) is a selective ligand for SR‐A, but there is evidence for an additional SR‐A‐independent, polyanion‐sensitive component for NM recognition. We therefore studied the relative contribution of MARCO and SR‐A to binding of NM by resident and elicited peritoneal macrophages obtained from MARCO–/–, SR‐A–/– and SR‐A‐MARCO–/– mice. Results confirmed that both mouse and human MARCO are able to bind NM independently of NM LPS. MARCO and SR‐A contributed independently to NM binding, correlating with their expression levels in different cell populations, but neither of these two molecules was required for release of TNF‐α and nitric oxide. We propose that the TLR‐dependent induction of MARCO by innate immune stimulation enhances recognition and uptake of pathogenic organisms such as NM, thus contributing to host defence against infection.
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