Judith D. Ochrietor, Blake T Bizzell
Dr. Judith D. Ochrietor | College of Arts and Sciences | Department of Biology
The innate immune system is the body’s first line of defense against foreign molecules. When white blood cells like monocytes encounter a foreign molecule, they initiate an immune response to eliminate that molecule and further infection. Metabolism is the biochemical reactions that happen inside a cell. Typically, cell metabolism increases in active cells. It would therefore be thought that metabolic processes would increase in monocytes that have become activated through the innate immune response. A study conducted by this laboratory, however, indicated that transporter proteins responsible for delivering metabolic substrates to cells were decreased in expression in response to an immune challenge. Therefore, the purpose of the present study was to determine if activated monocytes rely on substrates already found within the cell by using a process known as autophagy or “self-eating.” It was hypothesized that proteins involved in autophagy would increase in expression during an immune response as compared to normal, non-treated conditions. The RAW 264.7 cell line was treated with 1 g/mL lipopolysaccharide (LPS), which is a component of Gram-negative bacteria or with saline. After 24 hours, RAW 264.7 cellular proteins were isolated and the expression of four proteins known to be involved in various events in the autophagy process were analyzed via an ELISA. It was determined that no significant difference in expression was observed for the autophagy-specific proteins in the LPS-treated cells when compared to those treated with saline. The data indicate that activated monocytes do not undergo autophagy to support their metabolic needs.