The Neutrophil: An Underappreciated But Key Player in SLE Pathogenesis

Systemic lupus erythematosus (SLE) is a complex multi-organ autoimmune disease, the pathogenesis of which is still not deciphered. The neutrophil, an innate immune cell critical in controlling infections, has traditionally not been regarded as a contributor to systemic autoimmunity due to its lack of specificity and short lifespan. Many recent findings have instead shown that these cells have a role in regulating the adaptive as well as the innate immune response, and that they may play a key role in the abnormal responses seen in SLE. Neutrophils can secrete various cytokines and cellular mediators that can regulate both innate and adaptive arms of immunity, and may serve as a source of immunogens that may trigger and reinforce autoimmunity. In the present review we will discuss the relevance of neutrophil functions and neutrophil regulation of the immune response in the context of SLE.