Taming the neutrophil: Balance between anti‐parasite defence and pathogenesis

The dynamic relationship between the host immune response and an invading parasite is complex and challenging and can sometimes have costly consequences for the host. Well known for their role as first responders to a wide variety of infectious insults, neutrophils are appropriately armed to deal with and help clear invading pathogens through numerous mechanisms such as phagocytosis, degranulation and release of neutrophil extracellular traps (NETs). The production and release of these short-lived cells by the bone marrow is therefore often potently upregulated in response to infection. However, their defensive roles often come as a trade-off for the host, with the potential of neutrophils to contribute to disease pathogenesis if responses are not balanced. Here in this special issue of Parasite Immunology, a series of reviews explore the versatile range of neutrophil functions during parasite infections, uncovering under-appreciated roles in defence against a variety of protozoa and helminth organisms. They highlight technical advances to study neutrophil function and pose key questions that will advance our understanding of how neutrophil function can be balanced in order to help control parasite infections while maintaining host health.