Influence of Lifestyle Factors on Neutrophil Migration Pilot Study

This study will investigate how external factors implicated in immunity such as exercise, caffeine ingestion, ethanol, glucose, and glucose and caffeine ingestion influence neutrophil migration.

Neutrophils are the most prominent immune cell in human blood and are involved in a complex equilibrium of immune protection and autoimmune damage. Their recruitment to an inflammatory or wounding site is controlled by the sensing and directed migration to a concentration gradient of attractant molecules, a process called chemotaxis. Immune cells are also implicated in many diseases including cancer. The ability to measure the amplitude of a response over time for a specific patient, and the variation of this response when the patient engages in certain activities or consumes certain substances will improve understanding of how certain lifestyle factors impact the immune response. Traditional assays require large volumes of blood and a long purification process, which may affect neutrophil function and strictly limits the number of draws possible from a single patient. The novel microfluidic assay proposed limits these drawbacks as it has the capability to purify neutrophils from a 3 µL drop of blood in less than 5 minutes and measure their chemotaxis in a gradient of chemokines. Critically, the proposed studies will begin to fill a gap in current understanding of immune response as previous studies focused on single endpoints likely missing early events in the response to external stimulus. Understanding this temporal response may have implications in the development of new treatments as well as improvements in diagnosis of improper immune response.

The KOALA (Kit On A Lid Assay) approach was developed in Professor Dave Beebe's lab and has been validated in a mouse model and in human asthmatic patients. In a collaboration with Dr. Anna Huttenlocher, it has been shown that, in contrast to traditional neutrophil purification, KOALA can be performed with small volumes of blood, and a much quicker purification time.

Due to its unique qualities, KOALA allows for repeated evaluation of neutrophil adhesion and chemotaxis properties, thus making it an attractive method for studying dynamic neutrophil changes that may occur as a result of an external factor.

Using traditional macrobiology tools, researchers have identified several factors that may play important roles in reducing neutrophil responsiveness and migration ability. Lifestyle and diet factors, amongst others, have been shown to impact neutrophil count, migration and biochemical function. For example, sleep deprivation has been linked with higher neutrophil count, despite a known immuno-depressive effect. Physical exercise results in increased neutrophil counts and increased neutrophil degranulation. Dietary factors, such as caffeine and ethanol have been shown to impact immune function.