Discipline: Biological Sciences
Subcategory: Physiology and Health
Jelonia Rumph - Florida Memorial University
Co-Author(s): Frank Harris, Emory Children's Center, Atlanta, GA; Lou Ann Brown, Emory School of Medicine, Atlanta, GA.
Background: Anthrax is an infection caused by Bacillus anthracis. The clinical forms include: cutaneous, ingestion, injection and inhalation. There have been 24 documented cases of inhalation anthrax since the mid-20th century. 15 out of 24 patients died; 10 out of those 15 had an underlying chronic disease associated with oxidative stress. During inhalation anthrax, alveolar macrophages (AM) coordinate the immune responses. However, recent studies have shown that AM phagocytic index (PI), an indicator of microbe clearance, is decreased when they are exposed to oxidative stress.
Aims/Hypothesis: We aimed to investigate the role of oxidative stress in the susceptibility to anthrax. We hypothesized: AM exposed to oxidative stress will have a significantly decreased PI than control AM, but if oxidative stress AM are treated with arginine then their PI will improve.
Methods/Results: Using alcohol abuse as a model of oxidant stress, MH-S cell lines were cultured for 3 days in MH-S media, MH-S media/ethanol, MH-S media/arginine, or MH-S media/ethanol/arginine. Samples were exposed to Bacillus cereus spores and the PI was calculated and statistically analyzed. There was a significant difference between the MH-S media and the MH-S media/ethanol group. The P value calculated from the difference between these groups was 0.036269.
Conclusion: Oxidative stress decreases the PI of AM, hence increasing anthrax susceptibility. Arginine treatment provides a supply of precursors for antioxidant synthesis and improves the PI of oxidative stress AM. Future studies will include use of the Sterne strain of Bacillus anthracis.
Funder Acknowledgement(s): Project IMHOTEP, Center's for Disease Control CUPS
Faculty Advisor: Lou Ann Brown, PhD., firstname.lastname@example.org
Role: While conducting this research I was responsible for spiting and plating the cell lines. I was also responsible for synthesizing the MH-S media required for the Alveolar Macrophages. Once the cell were plated I exposed to Alveolar Macrophages to oxidative stress daily, using a ethanol/MH-S media solution, over a period of three days. I then exposed the cells to Bacillus cereus spores and incubated the slides for two hours. I then exposed the cells to a fluorescent antibody that tagged the spores and fixed the slides. Once the slides were fixed, I viewed them under the microscope capturing fluorescent and bright field images of various field of views. From the micrographs, I calculated the phagocytic index, and the relative florescent units per cell then ran statistical analyses.