Expanding roles of neutrophils in aging hosts

• Neutrophils are increasingly recognized as multi-faceted immune cells.
• In aged hosts, neutrophils show inaccurate chemotaxis and reduced NET formation.
• Neutrophils from aged hosts may induce or protect from tissue damage.
• Increased MDSCs in aged hosts suggest link to increased cancer incidence.
• New findings provide insights on how neutrophils may contribute to aging diseases.

Neutrophils’ role in the clearance of pathogens is well documented, but there is increasing appreciation that neutrophils can participate in the resolution of infection and inflammation. An obvious implication is that alteration of neutrophil functions with old age could significant impact both susceptibility of the host to infection and inflammatory conditions. Advances in recent years suggest additional chinks in the neutrophil antimicrobial arsenals in aged hosts, which render neutrophils less capable of killing pathogens. Moreover there is evidence that changes in neutrophil cross-talk with other immune cells also contribute to poor resolution of inflammation. These advances provide new insight on how these phagocytic cells could contribute to age-related diseases.