The role of gamma globulin, complement component 1q, factor B, properdin, body temperature, C-reactive protein and serum amyloid alpha to the activity and the function of the human complement system and its pathways.

Autor: Atosuo J; Laboratory of Immunochemistry, Department of Life Technologies, Faculty of Technology, University of Turku, 20140, Finland. Electronic address: janato@utu.fi., Karhuvaara O; Laboratory of Immunochemistry, Department of Life Technologies, Faculty of Technology, University of Turku, 20140, Finland. Electronic address: outkar@utu.fi., Suominen E; Laboratory of Immunochemistry, Department of Life Technologies, Faculty of Technology, University of Turku, 20140, Finland. Electronic address: ensuom@utu.fi., Virtanen J; Laboratory of Immunochemistry, Department of Life Technologies, Faculty of Technology, University of Turku, 20140, Finland., Vilén L; Department of Occupational Medicine, Clinical Department, Faculty of Medicine, 20140, University of Turku, Finland. Electronic address: liisa.k.vilen@utu.fi., Nuutila J; Laboratory of Immunochemistry, Department of Life Technologies, Faculty of Technology, University of Turku, 20140, Finland. Electronic address: jarnuu@utu.fi.
Jazyk: angličtina
Zdroj: Journal of immunological methods [J Immunol Methods] 2024 Aug; Vol. 531, pp. 113709. Date of Electronic Publication: 2024 Jun 09.
DOI: 10.1016/j.jim.2024.113709
Abstrakt: The complement system plays a crucial role in orchestrating the activation and regulation of inflammation within the human immune system. Three distinct activation pathways-classical, lectin, and alternative-converge to form the common lytic pathway, culminating in the formation of the membrane-attacking complex that disrupts the structure of pathogens. Dysregulated complement system activity can lead to tissue damage, autoimmune diseases, or immune deficiencies. In this study, the antimicrobial activity of human serum was investigated by using a bioluminescent microbe probe, Escherichia coli (pEGFPluxABCDEamp). This probe has previously been used to determine the antimicrobial activity of complement system and the polymorphonuclear neutrophils. In this study, blocking antibodies against key serum activators and components, including IgG, complement component 1q, factor B, and properdin, were utilized. The influence of body temperature and acute phase proteins, such as C reactive protein (CRP) and serum amyloid alpha (SAA), on the complement system was also examined. The study reveals the critical factors influencing complement system activity and pathway function. Alongside crucial factors like C1q and IgG, alternative pathway components factor B and properdin played pivotal roles. Results indicated that the alternative pathway accounted for approximately one third of the overall serum antimicrobial activity, and blocking this pathway disrupted the entire complement system. Contrary to expectations, elevated body temperature during inflammation did not enhance the antimicrobial activity of human serum. CRP demonstrated complement activation properties, but at higher physiological concentrations, it exhibited antagonistic tendencies, dampening the response. On the other hand, SAA enhanced the serum's activity. Overall, this study sheds a light on the critical factors affecting both complement system activity and pathway functionality, emphasizing the importance of a balanced immune response.
Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare.
(Copyright © 2023. Published by Elsevier B.V.)
Databáze: MEDLINE
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