Cd4+ T cell help as an indirect requirement for the development of functional Cd8+ T cell memory
Open Access
- Author:
- Cheung, Julie Fang
- Area of Honors:
- Immunology and Infectious Disease
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Sorujit Sarkar, Thesis Supervisor
James Endres Howell, Thesis Honors Advisor - Keywords:
- CD4
CD8
T Cell
Memory
Immune system
Immunological memory
Vaccine - Abstract:
- One of the largest contributors towards the success of a vaccine is the ability of the cells in the immune system to produce what is known as immunological memory, a specific characteristic of the adaptive arm in immunity The main effector cells during a vaccine immunization, and bacterial or viral infection are CD8+ T cells that directly combat pathogenic particles and infected cells. Some of these effector cells either die or become memory cells. These memory cells can persist in the body up to the lifetime of an individual and are activated to differentiate into effector cells when they recognize an invasion by the same pathogen. They respond in a stronger, much quicker fashion during this secondary response, and the time to clear infection noticeably decreases. There have been many studies that show that the help provided by CD4+ T cells are absolutely required for the production of functional CD8+ memory T cells using animal models. However a question that remains to be answered is whether or not the presence of CD4+ T cell is required for direct communication with CD8+ T cells. This thesis tests a hypothesis that perhaps the CD4+ T cell merely conditions the environment in some way that allows for the robust functionality of CD8+ memory T cells and thus suggesting an indirect requirement. CD4+ T cell–deficient mice and regular wild-type mice are infected with the Listeria Monocytogenes (LM) bacteria and then tested for their ability to produce functional CD8+ T cell memory. In each group, half are treated with Ampicillin and half remain untreated. The purpose of treatment is to bypass issue of persisting infection, in case CD8+ T cells become functionally exhausted. This otherwise would obscure results if CD8+ T cells result in having poor memory. Results in this experiment show that CD4+ T cell-deficient mice provide similar numbers in CD8+ T cells as wild-type mice. Further experimentation is required to determine whether CD8+ T cell is functional during a secondary recall response.