(4ca) Analyzing and Manipulating Endoplasmic Reticulum Stress and the Unfolded Protein Response in Various Cell Types

My research experience focuses on analyzing and engineering proteins, protein secretion, and ER stress across cell types, with a specialization in mammalian cells. As an undergraduate, I worked to measure enzyme activity of a Polymer Conjugated Enzyme (PCE) system designed to assist in metabolizing liver toxins in vivo. Early in my graduate career, I worked on projects focused on characterizing and engineering various yeast species for growth in ionic liquids and expression of lignin-degrading enzymes. These experiences jumpstarted my interests in genetic and protein engineering and therapeutic drug development and delivery. My dissertation work followed suit with characterizing the events and subsequent signaling leading to Chinese hamster ovary (CHO) cells undergoing stress during biomanufacturing. These host cells are the most common protein production platforms due to efficient post-translational modification machinery and endoplasmic reticulum (ER) quality control. However, high titers of recombinant proteins pose a burden and lead to an imbalance in ER homeostasis. Cell stress, as a result, can have a significant impact on productivity, product titer, and product quality, which are all of particular importance in production of therapeutics and pharmaceuticals. Accumulation of improperly folded proteins in the ER initiates the unfolded protein response (UPR) to restore ER homeostasis. My work has focused on understanding the dynamics of the UPR in CHO cell lines producing distinct protein products, with the aim to manipulate this signaling response for improving recombinant protein production. The research has given me experience with a wide-variety of techniques, including transcriptomic analysis, and I have been able to model the transient nature of the UPR in different CHO cell lines as well as identify new targets which are hypothesized to enhance protein folding.

Research Interests

Despite the negative connotation of ER stress, the UPR results in increased expression of multiple chaperones, and review of the literature, including my research, suggests highly productive CHO cell lines exhibit increased mRNA and protein levels of ER stress markers. Therefore, I hypothesize CHO cell genomic integration sites can be associated with a high productivity phenotype based on the extent of subsequent ER stress and UPR activation. This could have tremendous impacts for improving efficacious development of stable CHO cell lines. I would also like to extend this rationale to yeast species, since the UPR is a somewhat conserved mechanism in yeast, and these species have relevance in industrial production of a wide-range of products, including therapeutics. It would also be interesting to engineer yeast species to express mammalian chaperones in an attempt to improve protein folding in a host cell platform with more rapid and cheaper growth than CHO cells. My research has progressed through interpreting the results of similar studies involving various cell types such as HeLa cells, HEK293 cells, cancer cells, and various disease models such as prion disease, Parkinson disease, and Alzheimer’s disease. Additionally, many cell and tissue types apply the UPR in a distinct manner. I would like to expand my research to study ER stress and the UPR in other cell types and disease models which could have implications in multiple sectors, including the industrial and biomedical fields.

Teaching Interests

My teaching philosophy centers around teaching through the use of practical application, active and passive learning, and critical thinking. I enjoy having thought-provoking discussions with students with the goal of working towards answers for unique problems. By encouraging students to engage in creative inquiry, they establish an independent and confident research mindset. I believe in a well-rounded curriculum which teaches students the importance of making connections across courses within the chemical engineering curriculum as well as other disciplines. As a student, I experienced successful collaborative projects within my own department. As a graduate mentor, I saw first-hand how progress in research can be made more efficient by incorporating the expertise of individuals with tangential backgrounds. As faculty, I would like to work towards developing collaborative projects both within my given department as well as between my given department and other STEM-related disciplines, with the intention of working towards diversity and inclusivity. This has relevance both in industry and in academia, and would be beneficial for students by providing foundations for their future careers, regardless of track. I would apply my skills in pedagogy towards both undergraduate and graduate courses including, but not limited to, chemical reaction engineering, bioprocess engineering, and biomolecular engineering. While at Clemson University, I enjoyed participating in a course concerning the complexities of the central dogma in both prokaryotic and eukaryotic cells. This course was extremely useful for my research efforts. In order to expound on its concepts, I would like to establish a course specifically focused on protein engineering which would introduce students to the design of new proteins and how the design can impact the molecular properties of the protein’s stability, activity, and folding.

Teaching Experience

I have had a plethora of opportunities during my graduate career to hone my pedagogy skills. I was a teaching assistant in chemical engineering courses focused on mass and energy balances as well as biomolecular engineering. Throughout each academic year, I mentored several undergraduate students with tangential backgrounds who were interested in facilitating therapeutic protein production research. During the summer semesters, I worked to design and mentor projects with a variety of high schoolers participating in a five-week long program. I was awarded a departmental Graduate Assistance in Areas of National Need (GAANN) Fellowship, and I took an Engineering and Science Education course focused on teaching undergraduate engineering. I gained many experiences during the Fall 2020 semester. I worked with my fellow graduate students to initiate and develop a virtual tutoring program within my department. Through the program the collaborative contributions of several tutors, including myself, resulted in over 86 hours of tutoring assistance for middle and high school students. This program provides opportunities for a wide-range of individuals. It is my upmost interest to utilize my knowledge gained from this experience to initiate and develop a similar tutoring program within the department in which I am granted a faculty position. I was also given the opportunity to practice my teaching skills by working with a mentor to plan a virtual course in which I taught a module on recombinant DNA technology as part of a biomolecular engineering course. The module included four lectures, a homework assignment, and a final exam question. As part of the module, I designed teaching materials and assignments, and I evaluated student work for a total of 82 students. I also established a virtual office hour in order to develop a report with students and answer or assist with any questions or assignments. Lastly, I gave an invited lecture in which I taught students about naturally occurring biopolymers.