Rachael Workman Sparklin

Just like humans, bacteria utilize immune systems to detect, evade and eliminate infectious elements such as viruses. In Dr. Joshua Modell’s lab, we study many bacterial immune mechanisms, but my research focuses on the prokaryotic adaptive immune system CRISPR-Cas. The quandary that drove my thesis work is how bacteria can balance the benefits of immunity with the inevitable costs of carrying an immune system. We discovered that some bacteria repurpose the immune effector Cas9 to auto-regulate the production of the CRISPR-Cas system components. Furthermore, we found that this auto-regulatory mechanism, although it reduced immunity overall, was ultimately beneficial to the cells in minimizing autoimmune costs. Our work reveals an important mechanism through which bacteria can stably maintain immune systems while providing insights into novel functions of Cas9, as well as insight into regulators that could shape next-generation Cas9 therapeutic applications.

Questions & Answers

Why did you choose Johns Hopkins for your work?

Prior to beginning my Ph.D., I was a technician in the Johns Hopkins biomedical engineering department, developing methods and analysis techniques for long-read sequencing applications in the lab of Dr. Winston Timp. During my technician years, I got to know the broader JHU (Johns Hopkins University) community and collaborated with researchers in many departments. One thing that really stuck with me was how my opinions and insight were valued by P.I.s, postdocs and Ph.D. students throughout the campus, even though I did not have a Ph.D. myself. Overall, I found the collegiality and the resources available at Johns Hopkins to be unparalleled and didn’t want to be anywhere else for my Ph.D. research.

What does receiving this award mean to you personally and professionally? Do you have any connection with the particular award you received?

Receiving this award is incredible validation of the work I have done and continue to do, and it is an honor to be included in the list of Michael A. Shanoff and other Young Investigators’ Day award winners whom I respect and admire.

What contributed to your project’s success?

Beginning my Ph.D. with expertise developing sequencing applications and troubleshooting molecular assays allowed me to hit the ground running with my thesis work. What kept me motivated day to day was the excitement of assembling a molecular puzzle and poring over new data to see how it fit into or reshaped that puzzle. But most importantly, my lab mates and P.I. were all inextricably linked to my project’s success. The world class guidance, insight and mentoring provided by my thesis adviser, Josh Modell, the hard work of lab technicians Teja Pammi and Binh Nguyen, and the unconditional support, humor and baked goods from my friend and bay mate, Marie Stoltzfus, all greatly contributed to my project’s success.

What thoughts do you have about Young Investigators’ Day itself, as a celebration of the roles student and fellows play in research at Johns Hopkins?

Students and fellows are both the backbone and heart of research at Hopkins. Any opportunity to celebrate their dedication, resilience and accomplishments is important, inspirational and motivating to future students and fellows.

What has been your best/most memorable experience while at Johns Hopkins?

Our cohort’s coating ceremony was postponed and virtual because of COVID, so my friends and I had a picnic lunch and did our own white coat photo shoot in Patterson Park near the pagoda. It was wonderful to be able to celebrate this accomplishment together, think about how far we had come, and to get great pictures out of it as well.

What are your plans over the next year or so?

I hope to graduate this year and will be pursuing a research career in industry.

Tell me something interesting about yourself that makes you unique. Do you have any special hobbies, interests or life experiences?

Throughout my time as a Ph.D. student, I have been involved in fostering cats and kittens for the Baltimore Animal Rescue and Care Shelter (BARCS). I have been able to help over 40 animals get out of the animal shelter and into their new homes, several of which are the homes of Hopkins students and P.I.s.