A conformational change of C-reactive protein in burn wounds unmasks its proinflammatory properties.
Tissue damage in burn injury leads to a rapid increase of leukocytes and acute phase reactants. Plasma levels of C-reactive protein (CRP) rise within hours after the insult. No deficiency of this protein has been reported in humans, suggesting it plays a pivotal role in innate immunity. CRP in circulation is composed of five identical subunits [pentameric CRP (pCRP)]. Recently, deposits of structurally modified CRP (mCRP) have been found in inflammatory diseases. Little is known about this structural change and how it affects CRP functions. We analyzed CRP deposits in burn wounds and serum by immunohistochemistry, western blot and dot blot analysis. CRP was deposited in necrotic and inflamed tissue, but not in adjacent healthy tissue. Tissue deposited CRP was detected by mCRP-specific antibodies and structurally different from serum pCRP. mCRP but not pCRP induced reactive oxygen species production by monocytes and facilitated uptake of necrotic Jurkat cells by macrophages. In addition, it accelerated migration of keratinocytes in a scratch wound assay. The structural changes that occur in pCRP upon localization to damaged and inflamed tissue in burn wounds result in a functionally altered protein with distinct functions. mCRP exhibits opsonic, proinflammatory and promigratory properties which modulate wound healing.
Department of Plastic and Hand Surgery, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
David
D
Braig
Department of Plastic and Hand Surgery, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
Benedict
B
Kaiser
Department of Plastic and Hand Surgery, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
Jan R
JR
Thiele
Department of Plastic and Hand Surgery, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
Holger
H
Bannasch
Atherothrombosis and Vascular Biology Laboratory, Baker IDI Heart and Diabetes Institute, 74 Commercial Road, Melbourne, Victoria 3004, Australia.
Karlheinz
K
Peter
Department of Plastic and Hand Surgery, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
G Björn
GB
Stark
Institute for Biochemistry and Molecular Biology, Stefan-Meier-Str. 17, 79104 Freiburg, Germany.
Hans-Georg
HG
Koch
Department of Plastic and Hand Surgery, Medical Center - University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
Steffen U
SU
Eisenhardt
D017209:Apoptosis; D002056:Burns / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002097:C-Reactive Protein / Q000737:chemistry* / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000378:metabolism; D015603:Keratinocytes / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D011487:Protein Conformation; D017382:Reactive Oxygen Species / Q000378:metabolism; D012867:Skin / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014945:Wound Healing
D017382:Reactive Oxygen Species; D002097:C-Reactive Protein
acute phase reactants; burn injury; inflammation; innate immunity; wound healing