Spencer Lab Staff

John David Spencer, MD
Principal Investigator
John.Spencer@NationwideChildrens.org

John David Spencer, MD, is a physician-scientist and Chief of the Division of Nephrology and Hypertension. Dr. Spencer was raised in Valparaiso, Indiana and received his medical degree from Indiana University School of Medicine. He completed a pediatric residency and chief residency at Le Bonheur Children’s Hospital and the University of Tennessee Health Science Center. Dr. Spencer completed a pediatric nephrology fellowship at Nationwide Children’s Hospital and joined the Nationwide Children’s faculty in 2012. Dr. Spencer is a principal investigator in the Kidney and Urinary Tract Center and serves as co-director of this center. At the Ohio State University College of Medicine, he is a professor of pediatrics with tenure.

Dr. Spencer's National Institutes of Health-funded research program focuses on defining the molecular mechanisms that regulate and prevent infections in the kidney and bladder. His laboratories’ landmark findings demonstrate that small endogenous antimicrobial peptides play a key role in preventing infections and dysregulated production of these peptides may explain why children develop urinary tract infections. In addition, his laboratory has demonstrated that insulin regulates the expression of these peptides. Finally, his laboratory has shown that a rare population of cells within the kidney, called intercalated cells, contribute to defense against urinary tract infections by employing innate immune defenses and secreting antimicrobial peptides into the urine. Dr. Spencer’s research has been supported by the National Institutes of Health for over ten years and he currently is a principal investigator on three R01 awards and co-investigator on added awards. He is the author on more than 75 peer-reviewed publications.

In addition to his clinical nephrology practice and research endeavors, Dr. Spencer directs the Kidney and Urinary Tract Center’s SUPER summer program, which exposes underrepresented undergraduates and medical students to biomedical research and nephrology or urology practices. This program is supported by the National Institutes of Health and Dr. Spencer is the principal investigator for two mechanisms supporting these programs.

Laura Schwartz, PhD
Research Assistant Professor and Principal Investigator
Laura.Schwartz@NationwideChildrens.org

Laura Schwartz is a principal investigator in the Kidney and Urinary Tract Center and member of the Division of Nephrology and Hypertension at Nationwide Children's Hospital, and Research Assistant Professor of pediatrics at The Ohio State University College of Medicine. She was recruited to the Spencer Lab in 2018 as a research scientist and was promoted to faculty in 2023.

Laura graduated from University of Toledo in 2010 with a bachelor of science in Biological Sciences. She then did her doctoral training at Kent State University in the Kent State/Cleveland Clinic Foundation joint PhD program, graduating with a doctorate in Cell and Molecular Biology in 2015. Her doctoral research focused on the TGFb-mediated post-translational modifications to an RNA-binding protein, and its effect on translation of transcripts involved in the epithelial-to-mesenchymal transition. Following graduation, Laura worked as a scientist at CharlestonPharma, LLC, working on drug development of a monoclonal antibody for treatment of hematological and solid cancers. Currently, Laura’s research focus is on the regulation of expression of antimicrobial peptides in the urinary tract. The goal of the research is to identify therapeutic targets for the treatment or prevention of urinary tract infection to ameliorate the need for antibiotics.

Skye Bochter, PhD
Research Associate
Skye.Bochter@NationwideChildrens.org

Skye joined the Spencer Lab in 2020 as a research associate where his work has focused on examining the molecular mechanisms regulating expression of antimicrobial peptides, components of the innate immune system, in the urinary tract and kidney ant their role in preventing and clearing urinary tract infections. Skye received his bachelor's degree in Molecular Genetics from The Ohio State University. Subsequently, he earned his doctorate in Molecular Genetics at The Ohio State University in the MolGen Graduate Program under Dr. Susan E. Cole. His doctoral work was in vertebrate embryonic development and focused on understanding post-translational regulation of the Notch signaling pathway and its role in coordinating oscillatory gene expression during axial skeletal development.

Kristin Salamon
Research Associate
Kristin.Salamon@NationwideChildrens.org

Kristin received her bachelor’s degree in Biochemistry and Chemistry from Capital University in 2017. Her interest in drug discovery and novel therapeutics began early in her undergraduate studies when a family member enrolled into a life-saving clinical trial. Pursuing experience in translational research, Kristin is now a research associate in the Spencer Lab focusing on developing Ribonuclease 7, an antimicrobial peptide, as a therapeutic for urinary tract infections by studying its regulation in vivo.

Aaron Simoni
Research Associate
Aaron.Simoni@NationwideChildrens.org

Aaron received his bachelor's degree in Microbiology with a minor in Molecular Biology from Miami University. He then graduated from the University of Wisconsin – La Crosse with a master's in Clinical Microbiology. Aaron’s graduate work under Dr. Anne Galbraith investigated the mechanism of action for a novel plant-derived compound that exhibited antimicrobial properties using Saccharomyces cerevisiae as a model organism. Aaron joined the Spencer Lab in 2020 as a research assistant where he is interested in using mouse models to investigate the role of the innate immune system and antimicrobial peptides in preventing infections in the urinary tract.

Preeti John, PhD, a postdoctoral scientist in the Spencer lab, is a microbiologist who studies diabetic urinary tract infections (UTI). Dr. John completed her doctorate from the University of Louisiana at Lafayette in 2023. For her doctoral research, she worked on understanding the pathophysiology of Group B Streptococcal urinary tract infection in diabetes. She is continuing her work in diabetic UTI in the Spencer Lab focusing on the effect of aberrant insulin signaling in UTI. Her broader research interests include bacterial virulence, host immunity, and alternative models to understand host-pathogen interactions.

Vidhi Tyagi
Postdoctoral Scientist
Vidhi.Tyagi@NationwideChildrens.org

Guillermo Yepes Junquera
Infectious Disease Fellow
Guillermo.YepesJunquera@NationwideChildrens.org

Guillermo Yepes Junquera, MD, is a pediatrician and Infectious Disease fellow. Dr. Yepes was born and raised in Caracas, Venezuela and received his medical degree from Universidad Central de Venezuela, “Luis Razetti” School of Medicine. He completed a pediatric residency at Nationwide Children’s Hospital and joined the Pediatric Infectious Disease Fellowship program in July 2022 to continue his specialty training.

Dr. Yepes joined Spencer Lab in December 2022 and his main research project focuses on determining if antimicrobial peptides in the urinary tract synergize with commonly used antibiotic to augment their activity against Uropathogenic bacteria. From the clinical research standpoint, Dr. Yepes’ research is centered on understanding if the dysregulation or low concentrations of antimicrobial peptides in the urine serve as a risk factor of recurrent urinary tract infections.