This summer we’re sponsoring high school interns in stem cell labs throughout California. We asked those students to contribute to our Instagram photos and YouTube videos about life in the lab, and write about their experiences.
Yimin Yang worked in the lab of Drs. Anderson and Sharlie Barclay at the UC Davis Institute for Regenerative Cures.
Hello, my name is Yimin Yang, and I will be a senior at Davis Senior High School this upcoming fall. For the past two months, I have been interning at the UC Davis Institute for Regenerative Cures under the instruction of my mentors Dr. Anderson and Sharlie Barclay. I am currently working on the HIV Team, which seeks to develop an effective treatment for HIV through stem cell gene therapy. Since all the cells that HIV targets come from hematopoietic stem cells (HSCs), stem cell gene therapy could help treat and possibly cure patients with HIV.
For my project, I am testing the efficacy of a triple combination anti-HIV lentiviral vector. The vector is comprised of four parts: a CCR5 shRNA, a chimeric TRIM5α protein, a TAR decoy, and a CD25 pre-selective marker. The CCR5 shRNA binds to the mRNA of CCR5, a co-receptor that HIV needs to fuse its viral envelope with the plasma membrane, and prevents it from being translated into protein. This down-regulates the expression of CCR5 on the cell surface, thus impeding HIV’s entry into the cell. The chimeric TRIM5α targets the pre-integration and post-entry stages of the HIV life cycle, interfering with the process by which the virus uncoats its capsid. The TAR decoys bind to TAT proteins and inhibit the TAT-TAR interactions which play an integral role in effective transcription of HIV. Finally, the CD25 pre-selective marker helps us select for the cells which been transduced.
To test for the efficacy of this vector, my mentors and I challenged transduced macrophages with HIV-1 and measured the levels of P24 at various time points over a period of four weeks. When we compared these results to the control, we found that the transduced macrophages had successfully developed resistance to HIV. We also tested for CCR5 down-regulation in GHOST cells through flow cytometry; this too yielded encouraging results as CCR5 expression was significantly lower in transduced cells as opposed to nontransduced controls.
In addition to the efficacy experiments, I also spent time in the lab helping to produce more of the vector. I made LB broth for bacteria cultures, extracted plasmids, and transfected HEK-293T cells. From performing these protocols, I gained valuable insight into what it is like to work in a professional research facility. I learned how important it is to have good sterile technique and work efficiently. This internship has also opened my eyes to the fascinating world of stem cell research through the BIO225 class that we had to take as a part of the program. Although I had some basic knowledge regarding stem cells, I was still unaware of the wide range of potential applications they had in the medical field. Outside of tissue repair and regenerative medicine, stem cells could also be utilized in gene therapy to treat for genetic and infectious diseases. Overall, this course has not only helped to reinforce my understanding of the topic from my work in the lab, but also introduced me to a variety of new, exciting concepts.
As I had often considered pursuing a career as a research scientist, this experience has certainly cemented my interest in the field and given me a clearer vision of the path I wish to follow in the future.
I would like to thank Dr. Bauer and my mentors, Dr. Anderson and Sharlie Barclay, for all the help and guidance they have given me. I am also incredibly grateful to CIRM, the UC Davis Stem Cell Program, and everyone else who made the Creativity Program possible, as my internship this summer has been completely amazing and utterly unforgettable.