RESUMO
Objective: To establish the stable methodology for screening antagonists of CD88, one of C5a receptors. Methods: Whole blood from volunteers was collected and then stimulated by C5a with different concentration for 10-30 min in the presence or absence of PMX-53 and LPS. Flow cytometry was used to detect the expression of CD11b which on the surface of neutrophil. Other functions of nentrophil, including lysozyme release, oxidative burst and interleukin (IL)-8 production, were also examined respectively. Finally, western blotting was used to detect the content of total and phosphorylated ERK and AKT. Thus, the effects about C5a receptor stimulant and the positive medicine PMX-53 on biochemical indicators were investigated. Results: The C5a stimulation actively up-regulated CD11b expression, evoked lysozyme and reactive oxygen species release, increased the IL-8 production and the contents of total and phosphorylated ERK/AKT. While the positive medicine PMX-53 significantly blocked these effects. Conclusion: The methodology in vitro for screening C5a receptor antagonists inhuman whole blood is successfully established.
RESUMO
As one of the most important products of complement activation, C5a, after binding to ts receptors (C5aR), has been considered to be involved n the pathology of numerous inflammatory diseases, such as acute ung njury, sepsis, rheumatoid arthritis and glomerular nephritis. Therefore, the focus of current studies on how to block C5a and C5aR signal transduction for dampening the inflammatory reaction. Recently, several antagonists of C5a and C5aR were reported, including C5a antibody, small molecule human C5aR antagonists, C5a antisense peptide, C5a mutant and the complex of chemotaxis inhibitory protein of Staphylococcus aureus with C5aR. In this review, the structure and function of C5a and C5aR, and the advances n the research on their antagonists are summarized.