Journal
JOURNAL OF LEUKOCYTE BIOLOGY
Volume 73, Issue 6, Pages 802-814Publisher
WILEY
DOI: 10.1189/jlb.0602319
Keywords
macrophage-stimulating protein; complement receptor 3; intercellular adhesion molecule-1
Categories
Funding
- NIAID NIH HHS [AI43367] Funding Source: Medline
Ask authors/readers for more resources
Macrophage-stimulating protein (MSP) promotes the phagocytosis of C3bi-coated erythrocytes by resident peritoneal macrophages, although the mechanism by which this occurs is largely unknown. We show that MSP-induced complement-mediated phagocytosis requires the RON receptor tyrosine kinase and the alphaMbeta2 integrin, as evidenced by the inability of RON-/- and alphaM-/-peritoneal macrophages to augment phagocytosis of complement-coated sheep erythrocytes in response to MSP. MSP stimulation of macrophages results in tyrosine phosphorylation and AKT activation, and inhibitor studies demonstrate a phagocytic requirement for tyrosine kinase and phosphatidylinositol 3-kinase (PI-3K) activity as well as activity of the atypical protein kinase C (PKC) isoform, which localizes to MSP-induced phagosomes containing complement-coated beads. Additionally, MSP augments the ability of peritoneal macrophages to bind to intercellular adhesion molecule-1 (ICAM-1) via the alphaMbeta2 integrin. MSP-induced ICAM-1 adhesion is also dependent on tyrosine kinase activity, PI-3K, and PKC xi, indicating that these signaling requirements are upstream of complement receptor 3 activation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available