| Literature DB >> 17362929 |
Eyal Amiel1, Susan Nicholson-Dykstra, Julie Jo Walters, Henry Higgs, Brent Berwin.
Abstract
Class-A scavenger receptors (SR-A) are cellular pattern recognition receptors that bind and traffic a variety of endogenous and microbial ligands. However, despite an emerging role for SR-A as a contributor to the innate immune system, little is known of the regulation or function of SR-A on dendritic cells (DCs). Here we show that SR-A expression is upregulated during murine DC differentiation and that SR-A expression levels correlate with the expression of the murine DC marker CD11c. Using bone marrow-derived DCs (BMDCs) from SR-A knockout (SR-A(-/-)) mice, we investigated the contribution of SR-A to BMDC particulate phagocytosis. Functional analyses demonstrated that SR-A is a critical phagocytic receptor for BMDC internalization of the gram-negative bacteria E. coli. SR-A(-/-) BMDCs were impaired in their ability to phagocytose bacteria, and this deficit varied with the bacteria:BMDC cell ratio. Microscopic and biochemical analyses revealed that SR-A is broadly distributed on the surface of BMDCs and is not physically associated with lipid rafts. However, cholesterol depletion demonstrated dependence of SR-A-mediated phagocytosis upon lipid rafts. These data demonstrate a functional contribution for SR-A in the BMDC phagocytic pathway.Entities:
Mesh：
Substances：
Year: 2007 PMID： 17362929 PMCID： PMC1905149 DOI： 10.1016/j.yexcr.2007.02.011
Source DB: PubMed Journal: Exp Cell Res ISSN： 0014-4827 Impact factor: 3.905