Characteristics and Biological Variations of M-Ficolin, a Pattern Recognition Molecule, in Plasma
2009; Karger Publishers; Volume: 2; Issue: 2 Linguagem: Inglês
10.1159/000218324
ISSN1662-8128
AutoresThomas R. Wittenborn, Steffen Thiel, Lisbeth Jensen, Hans Jørgen Nielsen, Jens C. Jensenius,
Tópico(s)Immune Cell Function and Interaction
ResumoThe three human ficolins, H-ficolin, L-ficolin and M-ficolin, are pattern recognition molecules of the innate immune system. All three ficolins can activate the lectin pathway of the complement system after binding to pathogens. H- and L-ficolin are serum proteins with an average concentration of 18 and 3 µg/ml, respectively. M-ficolin has been described as a membrane-associated pattern recognition receptor of monocytes, being also present in granulocytes; recently, minuscule amounts of M-ficolin have been found in serum, too. No assay specific for M-ficolin has yet been described and biological variations are unknown. We have raised specific monoclonal anti-human M-ficolin antibodies and have developed a quantitative assay for M-ficolin. M-ficolin elutes as a large, 900-kDa protein upon gel permeation chromatography of serum. Analysis of M-ficolin levels in serum samples of 350 blood donors reveals a mean concentration of 1.07 µg/ml, ranging from 0.28 to 4.05 µg/ml. Analyses of consecutive acute phase serum samples from major surgery patients indicated a complex response. Ontogeny was investigated through cord blood samples from healthy full-term babies, which showed adult levels, with sequential samples showing no increase from birth to 1 year of age. We suggest that M-ficolin should also be considered as a humoral pattern recognition molecule.
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