6th Annual Judith Ramaley Celebration of Research and Creative Scholarship
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Poster #38 Histophilus somni Causes Extracellular Trap Formation by Bovine Neutrophils and Macrophages
Katelyn Forsythe
Faculty Mentor: Nicole Aulik
Bovine respiratory disease (BRD) is a fibrinous pleuropneunomonia caused by a combination of bacterial and viral pathogens, also known as shipping fever. One causative agent of BRD is the Gram-negatice coccobacillus Histophilus somni. Recently, bovine neutrophils and macrophages have been found to produce extracellular traps (ETs) in response to certain bacteria. This is a form of cell death, termed ETosis, causes the release of antimicrobial-studded deoxyribonuleic acid (DNA) into the extracellular environment from activated neutrophils. This process occurs without phagocytosis in which bacteria are trapped and killed in the ET complexes. Here, we demonstrate that H. somni causes ET formation from bovine neutrophils and macrophages that trap and destroy H. somni cells. There are two main focal points for our research: to confirm that H. somni causes NET formation and characterize that formation and to determine if H. somni causes macrophage extracellular trap formation, which has only been recently discovered. ETs were quantified using the fluorescent marker PicoGreen, in which we confirmed that H. somni causes ETs from bovine neutrophils and macrophages. Confocal and scanning electron microscopy was also used to visualize the extracellular traps. Neutrophil ETs produced in response to H. somni did trap and kill the bacterial cells. Identification of these ETs in response to H. somni provides us with a better understanding of how the innate immune response interacts with this pathogen. We expect this research will lead us to a better understanding of the role ETs play during an infection with H. somni. |
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