Bilal Elfayoumi, COL ’26, Williamsport, PA
This summer, I served as a research intern supervised by Dr. Chris Bennett. The Bennett Lab studies the roles of brain-resident immune cells in health and disease. I worked on a variety of projects, accumulating numerous technical and intangible skills along the way.
First, I sought to understand the role of T cells in Krabbe disease (KD). KD is a lysosomal storage disease in which mutations in Galc cause significant demyelination and neuroinflammation. Other lab members found that mouse models of KD (twitcher) had significantly higher numbers of T cells compared to healthy mice (WT) and a recent study found that depleting T cells improved KD pathogenesis. I wondered whether the clinical benefit in settings of T cell depletion was due to reduced neuroinflammation. To test whether depleting T cells reduced neuroinflammation, I depleted T cells from twitcher mice, harvested brains for immunostaining, and measured the intensity of GFAP protein expression in the brain – a common readout of neuroinflammation. I found that T cell depleted twitcher brains had much lower levels of GFAP compared to non-depleted twitcher brains, suggesting that T cells promote neuroinflammation in KD. This process involved learning how to design histology experiments, work with mice, harvest tissues, prepare tissues for immunostaining, staining tissues with fluorescent antibodies, imaging slides, and building analysis pipelines. Learning this entire process helped me obtain a grasp on what being a scientist truly meant. By designing my own experiment and consulting with my mentors on what the best course of action would be I was able to learn so much from this initial experience.
Second, I sought to understand whether macrophages from twitcher mice demonstrated an inability to change inflammatory states. In KD, macrophages are dysfunctional and worsen pathology; however, it is unclear how they are dysfunctional. Key to macrophage function is their ability to transition between proinflammatory (M1) and immunoregulatory (M2) states in response to environmental needs. I wondered whether defective GALC impacted their ability to transition between these inflammatory states. To test this, I stimulated WT and twitcher macrophages with cytokines that polarize cells into an M1 state and measured expression of M1 genes. I found that twitcher macrophages expressed higher levels of M1 genes in response to M1 cytokines compared to WT macrophages, suggesting that twitcher macrophages may be biased to polarize into proinflammatory M1 states. This process involved learning how to do cell culture, design qPCR experiments, validate qPCR primers, assess reference gene stability, and perform delta delta Ct gene expression analyses. This entire process came with a lot of conflicts, as qPCR was new to myself and the lab so I had no real solid framework to base myself off of. I would constantly be reading over different protocols that other labs had tried in addition to researching the necessary conditions for a successful qPCR assay only to find myself failing again and again. However with persistence I was able to successfully create my own qPCR protocol thanks to the countless trials I attempted over the past few months, and I must say it was a very good feeling. Overall these past few months within the Bennett lab have helped solidify my interests in immunology and neuroscience, while simultaneously aiding me in learning countless technical lab skills in addition to being able to think as a scientist. I want to thank Career Services for providing me with this invaluable opportunity. After this summer’s experience I can now say with full confidence I wish to become a Physician-Scientist, with the goal of continuing to study neuroimmunology.
This is part of a series of posts by recipients of the 2023 Career Services Summer Funding Grant. We’ve asked funding recipients to reflect on their summer experiences and talk about the industries in which they spent their summer. You can read the entire series here
