Interaction of Bartonella henselae with endothelial cells promotes monocyte/macrophage chemoattractant protein 1 gene expression and protein production and triggers monocyte migration.
Bacillary angiomatosis (BA), one of the many clinical manifestations resulting from infection with the facultative intracellular bacterium Bartonella henselae, is characterized by angiogenic lesions. Macrophages have been identified as important effector cells contributing to the angiogenic process during B. henselae infection by infiltrating BA lesions and secreting vascular endothelial growth factor. Monocyte-macrophage chemoattractant protein 1 (MCP-1) recruits macrophages to sites of inflammation. In this study, we investigated the ability of B. henselae to upregulate MCP-1 gene expression and protein production in the human microvascular endothelial cell line HMEC-1. MCP-1 mRNA was induced at 6 and 24 h after treatment with bacteria, whereas protein production was elevated at 6, 24, and 48 h. This induction was not dependent on the presence of bacterial lipopolysaccharide or endothelial cell toll-like receptor 4. However, MCP-1 production was dependent on NF-kappaB activity. Outer membrane proteins of low molecular weight were able to upregulate MCP-1 production. Furthermore, supernatants from B. henselae-infected HMEC-1 were able to induce chemotaxis of THP-1 monocytes. These data suggest a mechanism by which the macrophage effector cell is recruited to the endothelium during B. henselae infection and then contributes to bacterial-induced angiogenesis.
McCord
Amy M
AM
Department of Medical Microbiology and Immunology, College of Medicine, University of South Florida, MDC10, 12901 Bruce B. Downs Blvd., Tampa, FL 33612, USA.
Burgess
Andrew W O
AW
Whaley
Melissa J
MJ
Anderson
Burt E
BE
D001425:Bacterial Outer Membrane Proteins / Q000502:physiology; D018416:Bartonella henselae / Q000502:physiology*; D002450:Cell Communication / Q000276:immunology*; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D018932:Chemokine CCL2 / Q000096:biosynthesis / Q000235:genetics*; D002633:Chemotaxis / Q000502:physiology; D004730:Endothelium, Vascular / Q000382:microbiology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000502:physiology; D009000:Monocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D016328:NF-kappa B / Q000502:physiology; D011956:Receptors, Cell Surface / Q000502:physiology; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors
D001425:Bacterial Outer Membrane Proteins; D018932:Chemokine CCL2; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D011956:Receptors, Cell Surface; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors