LOX-1 supports adhesion of Gram-positive and Gram-negative bacteria.
Adhesion of bacteria to vascular endothelial cells as well as mucosal cells and epithelial cells appears to be one of the initial steps in the process of bacterial infection, including infective endocarditis. We examined whether lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), a member of scavenger receptor family molecules with C-type lectin-like structure, can support adhesion of Gram-positive and Gram-negative bacteria. Chinese hamster ovary-K1 (CHO-K1) cells stably expressing LOX-1 can support binding of FITC-labeled Staphylococcus aureus and Escherichia coli, which was suppressed by poly(I) and an anti-LOX-1 mAb. Adhesion of these bacteria to LOX-1 does not require divalent cations or serum factors and can be supported under both static and nonstatic conditions. Cultured bovine aortic endothelial cells (BAEC) can also support adhesion of FITC-labeled S. aureus, which was similarly suppressed by poly(I) and an anti-LOX-1 mAb. In contrast, binding of FITC-labeled E. coli to BAEC was partially inhibited by the anti-LOX-1 mAb, and poly(I) did not block FITC-labeled E. coli adhesion to BAEC, but, rather, enhanced it under a static condition. TNF-alpha increased LOX-1-dependent adhesion of E. coli, but not that of S. aureus, suggesting that S. aureus adhesion to BAEC may require additional molecules, which cooperate with LOX-1 and suppressed by TNF-alpha. Taken together, LOX-1 can work as a cell surface receptor for Gram-positive and Gram-negative bacteria, such as S. aureus and E. coli, in a mechanism similar to that of class A scavenger receptors; however, other unknown molecules may also be involved in the adhesion of E. coli to BAEC, which is enhanced by poly(I).
Shimaoka
T
T
Institute for Virus Research and Department of Geriatric Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Kume
N
N
Minami
M
M
Hayashida
K
K
Sawamura
T
T
Kita
T
T
Yonehara
S
S
D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D016466:CHO Cells; D019556:COS Cells; D002417:Cattle; D002448:Cell Adhesion / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D006224:Cricetinae; D004730:Endothelium, Vascular / Q000166:cytology / Q000382:microbiology / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D011069:Poly I / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects / Q000276:immunology; D011973:Receptors, LDL / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; D013211:Staphylococcus aureus / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D011973:Receptors, LDL; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; D014409:Tumor Necrosis Factor-alpha; D011069:Poly I