Bakos T, Kozma GT, Szebeni J, Szénási G. Eculizumab suppresses zymosan-induced release of inflammatory cytokines IL-1α, IL-1β, IFN-γ and IL-2 in autologous serum-substituted PBMC cultures: Relevance to cytokine storm in Covid-19.
Biomed Pharmacother 2023;
166:115294. [PMID:
37567071 DOI:
10.1016/j.biopha.2023.115294]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND AND OBJECTIVE
Cytokine storm (CS) is a major contributor to the fatal outcome of severe infectious diseases, including Covid-19. Treatment with the complement (C) C5 inhibitor eculizumab was beneficial in end-stage Covid-19, however, the mechanism of this effect is unknown. To clarify this, we analyzed the relationship between C activation and production of pro-inflammatory cytokines in a PBMC model.
METHODS
Human PBMC with or without 20 % autologous serum was incubated with C3a, C5a, zymosan or zymosan-pre-activated serum (ZAS) for 24 h with or without eculizumab or the C5a receptor antagonist, DF2593A. C activation (sC5b-9) and 9 inflammatory cytokines were measured by ELISA.
RESULTS
In serum-free unstimulated PBMC only IL-8 release could be measured during incubation. Addition of C5a increased IL-8 secretion only, ZAS induced both IL-2 and IL-8, while zymosan led to significant production of all cytokines, most abundantly IL-8. In the presence of serum the above effects were greatly enhanced, and the zymosan-induced rises of IL-1α, IL-1β IFN-γ and IL-2 were significantly attenuated by eculizumab but not by DF2593a.
CONCLUSIONS
These data highlight the complexity of interrelationships between C activation and cytokine secretion under different experimental conditions. The clinically relevant findings include the abundant formation of the chemokine IL-8, which was stimulated by C5a, and the suppression of numerous inflammatory cytokines by eculizumab, which explains its therapeutic efficacy in severe Covid-19. These data strengthen the clinical relevance of the applied PBMC model for drug screening against CS, enabling the separation of complex innate immune cross-talks.
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