Neutrophils: A critical participator in common diseases of ruminants

Abstract

Neutrophils, pivotal effector cells involved in innate immunity, play a central role in various infectious and inflammatory diseases. Using a powerful phagocytic killing mechanism, these cells protect the host by destroying the invading pathogens. However, these cells can also cause varying degrees of tissue damage if their activation is not finely controlled. In recent years, the involvement of neutrophils in human diseases has been extensively studied, while their roles in ruminant diseases have rarely been investigated. In the present review, we mainly summarize current knowledge regarding the characteristics and functions of neutrophils in ruminants such as goats and cattle. We emphasize the involvement of these cells in several common diseases such as mastitis, Brucellosis, Mycoplasma bovis infection and parasitic infections, among others. We also focus on discussing the relevant mechanisms and signaling pathways underlying these observations. In addition, we compare the phenotypes and functions of neutrophils of different ruminant species. The studies about ruminant neutrophils should help elucidate the pathogenesis of many ruminant diseases and ultimately shed light on the development of novel therapeutics for these diseases.