Effects of nutrition on neutrophil function in preclinical studies

Although neutrophils are an essential component of natural immunity, their activities must be carefully regulated to prevent detrimental prolonging of inflammation. To resolve inflammation, neutrophil recruitment to the affected tissue must be blocked, and neutrophils in the tissue must be removed by apoptosis and phagocytosis. Polyunsaturated fatty acids (PUFAs) are a major dietary regulator of immune function. N-3 PUFAs and n-6 PUFAs modulate the inflammatory response in neutrophils. N-3 PUFA exhibits anti-inflammatory activities through neutrophils using multiple mechanisms including decreasing neutrophil chemotaxis in response to inflammatory stimuli, reducing neutrophil adhesion to the vascular endothelium and neutrophil transmigration across the endothelium and into the affected tissue, and promotes the synthesis of resolvins and protectins, inflammation-resolving lipids that promote neutrophil apoptosis and phagocytosis. Sepsis and acute respiratory distress syndrome, common conditions in critical care patients, are both a result of dysregulated or excessive inflammation. Preclinical data obtained from rodent models and cell culture studies support a role in nutritional immunomodulation using n-3 PUFAs or their derivatives in patients with sepsis or acute lung injury.