Calcium requirements for vitronectin-mediated phagocytosis of Staphylococcus aureus by human neutrophils
(English)Manuscript (preprint) (Other academic)
In this paper we have shown that the intracellular free calcium concentration ([Ca2+]i) in human neutrophils regulates phagocytosis of Staphylococcus aureus adherent to vitronectin-coated surfaces. When neutrophils were allowed to phagocytose bacteria bound to vitronectin- or albumin-coated surfaces in tbe presence of Ca2+, there were no obvious differences in the phagocytic activity. Ca2+-depleted neut:ropbils showed a reduced phagocytic activity on vitronectin-coated surfaces. However, the phagocytosis on albumin-coated surfaces was unaffected. Adding extracellularly Ca2+ restored the reduced phagocytic activity in Ca2+-depleted neutrophils on vitronectincoated surfaces. Similarly, using a GRGDSP-peptide to block tbe RGDmediated integrin attachment of tbe neutrophils to vitronectin restored tbe reduced phagocytic activity in Ca2+-depleted cells. Studying phagocytosis in non-migrating neutrophils adherent to vitronectin showed that ingestion of S. aureus occurred independently of Ca2+. This indicate that Ca2+ regulate the phagocytic activity of neutrophils on vitronectin-coated surfaces by regulating integrin-dependent cell directed motility.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-79588OAI: oai:DiVA.org:liu-79588DiVA: diva2:543861