Daniel is currently pursuing a degree in biology with a focus on neurobiology at North Carolina State University (NCSU). However, Daniel’s journey to the 2013 SRF Summer Internship Program is quite unique. He began his research career in 2004 exploring the genomic basis of fungal resistance in melons with Dr. Tarek Joober at NCSU. While pursuing a degree in psychology at the University of North Carolina-Chapel Hill (UNC), Daniel used EEG, fMRI and eye-tracking paradigms to study the effects of memory on attentional control under the supervision of Dr. Joseph Hopfinger. After studying cognitive science for two years at the University of Cincinnati, Daniel decided a “bottom-up” approach was more amenable to his research interests and enrolled at NCSU where he is currently attempting to develop a zebrafish model of trait-level anxiety under the mentorship of Dr. John Godwin.
For his 2013 SRF Summer Internship, Daniel joined ongoing SRF-supported work at Dr. John Jackson’s laboratory at the Wake Forest Institute of Regenerative Medicine, where he attempted to develop a method for growing thymus tissue ex vivo.
Generation of thymus ex vivo
The thymus is an essential component of the immune system, which configures T-cells to meet novel threats. An individual without a thymus would have a severely compromised immune response. Unlike most organs, the thymus reaches its maximum size and functionality around the onset of puberty after which it atrophies, leading to a decline in the immune system’s ability to respond to new threats. If it were possible to prolong the viability of the thymus, or even revitalize it later in life, we might be able to bolster the body’s defences against threats such as viruses, autoimmune diseases, and even cancer.
Our goal was to develop a method for growing a transplantable thymus, using donor thymus cells to colonize a scaffold containing an extracellular matrix, the mesh of tissue components found between cells. This entailed a number of intermediary steps, including harvesting thymic tissue from porcine donors, the decellularization of those tissues (i.e. reducing the tissue to an extracellular matrix), the harvesting of epithelial cells from murine donors, and finally the culturing of potential donor thymus tissue. Although these procedures have been successfully implemented in the past for a number of other organs and tissues, the precise protocols are only partly applicable for work with the thymus. Thus, a new protocol needed to be developed and optimized.
Figure 1. Pig thymus after 2-9 days of Triton X-100 washing (H&Estain).
From left to right, top to bottom: wash days 2-9, 1% Triton x-100, 200x
I performed a number of quantitative assessments to measure the optimization of the decellularization process and growth of thymic epithelial cell populations in vitro. Additionally, I also characterized the microphysical and biological features of the newly decellularized material. Our initial results have been promising and, as my internship was coming to a close, the lab was preparing to begin transplantation experiments in a live mouse model.
Daniel plans to graduate from North Carolina State University in the spring of 2015 with a bachelor’s degree in biology as well as minors in genetics and mathematics. After graduation, he hopes to enrol in a computational neuroscience program and continue his pursuit to understand the how the mind works.