Purified complement C3b triggers phagocytosis and activation of human neutrophils via complement receptor 1.

ABSTRACT: The complement system provides vital immune protection against infectious agents by labeling them with complement fragments that enhance phagocytosis by immune cells. Many details of complement-mediated phagocytosis remain elusive, partly because it is difficult to study the role of individual complement proteins on target surfaces. Here, we employ serum-free methods to couple purified complement C3b onto E. coli bacteria and beads and then expose human neutrophils to these C3b-coated targets. We examine the neutrophil response using a combination of flow cytometry, confocal microscopy, luminometry, single-live-cell/single-target manipulation, and dynamic analysis of neutrophil spreading on opsonin-coated surfaces. We show that purified C3b can potently trigger phagocytosis and killing of

SUBMITTER: Boero E 

PROVIDER: S-EPMC9822988 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature