Abstract
Neutrophils play a key role in the human immune response to Staphylococcus aureus infections. These professional phagocytes rapidly migrate to the site of infection to engulf bacteria and destroy them via specialized intracellular killing mechanisms. Here we describe a robust and relatively high-throughput flow cytometry assay to quantify phagocytosis of S. aureus by human neutrophils. We show that effective phagocytic uptake of S. aureus is greatly enhanced by opsonization, i.e. the tagging of microbial surfaces with plasma-derived host proteins like antibodies and complement. Our rapid assay to monitor phagocytosis can be used to study neutrophil deficiencies and bacterial evasion, but also provides a powerful tool to assess the opsonic capacity of antibodies, either in the context of natural immune responses or immune therapies.
Highlights
Staphylococcus aureus is a leading pathogen causing an array of serious and possibly fatal diseases in humans [1]
In our standard assay set up we mix neutrophils with bacteria previously opsonized with pooled serum from healthy donors (normal human serum (NHS)), to enhance the engagement of cell surface receptors
As described in detail in the methods section, we evaluated the outcome of phagocytosis from cell-derived parameters
Summary
Staphylococcus aureus is a leading pathogen causing an array of serious and possibly fatal diseases in humans [1]. Due to its fast acquisition of antibiotic resistance, treatment of S. aureus infections is becoming increasingly difficult [2]. Alternative measures such as vaccine candidates tested so far were unsuccessful [3, 4], new research efforts are urgently required. Patients with compromised neutrophil function are more susceptible to S. aureus infections [5]. This suggests that studying the role of neutrophils in the clearance of different clinical strains of this bacterium could provide us with clues to develop therapies. Neutrophils are the most abundant professional phagocytes of the innate immune system.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
