Investigating the Role and Localization of B Cells in the Red-Eared Slider, Trachemys Scripta

Abstract

The immune system of humans has been studied extensively, but very little is known about the immune response in reptiles. Our lab has been working to better understand the immune system of a pond turtle, Trachemys scripta (red-eared slider). Turtles are known for their longevity and their immune system should play an important role in their ability to survive. Our main interest is understanding B cell function and location in slider turtles. B cells are a type of white blood cell that play a vital role in the immune response of humans, with the majority secreting antibodies that mark invading bacterial cells to be destroyed. Some B cells can ingest pathogens directly in order to get rid of them through a process known as phagocytosis. We first confirmed that turtle B cells can survive cell sorting. Next, we investigated the phagocytic properties of turtle B cells. The phagocytic cells were sorted on a flow cytometer. This showed that phagocytic B cells could also survive being sorted. The sorted cells were used to complete an ELISpot assay to see if B cells could produce antibodies after phagocytosis. The results show that the B cells do produce antibodies after phagocytosis. Lastly, we wanted to look at the location of B cells in the intestines of turtle hatchlings. We were able to identify B cell clusters within hatchling intestines by using immunohistochemistry. Knowing the location of B cells helps us understand how reptiles use this tissue to defend against pathogens. KEYWORDS: Turtle, immunity, B cells, phagocytosis, flow cytometry, immunohistochemistry