Gavin Campbell, Sedem Dankwa, Casey Hammett, Noa Schork, Katie Soden, Aren Watt
Faculty Sponsor: Sophia Sarafova
Our group investigation class explored the relationship between the microbiome and the homeostasis of helper CD4+ and killer CD8+ T cells. Previous research at Davidson College has identified a laboratory mouse strain in our facility, B10.A, with a reduced CD4/CD8 ratio in peripheral lymphoid organs and blood, while the parental B10 strain has a normal ratio. Both mouse strains living under Specific Pathogen Free (SPF) conditions exhibit a normal CD4/CD8 ratio. One important difference between SPF and conventional animal facilities is the gut microbiome composition, which directly correlates with immune health. Therefore, we aimed to change the microbiome composition and determine whether there will be a corresponding change in the CD4/CD8 ratio of the two mouse strains. The treatment of choice was a 3-4 week regiment of supplementing with a prebiotic, inulin, in the drinking water. Keeping in mind that there are sex differences in the CD4/CD8 ratio we divided B10 and B10.A mice into eight groups, such that for each strain we had a treated and an untreated group for both sexes. We also kept track of the age, as it can influence the CD4/C8 ratio as well. For each group we collected fecal pellets before and after treatment for future analysis. Also, we measured the anatomical features of the gut and determined the CD4/CD8 ratio in the blood before and after treatment. Finally, we measured the CD4/CD8 ratio in gut-associated lymphoid organs, such as the mesenteric lymph nodes and the Peyer’s Patches, in one mouse for each group. We found some differences in the CD4/CD8 ratio in the presence or absence of prebiotic treatment, but we cannot form any conclusions before the microbiome data analysis is complete.