Lab Members


  • Jim Chappell, MD, PhD

    Research Associate Professor
    Pediatric Infectious Disease

    My scientific background broadly encompass the pathogenesis, etiology, epidemiology, and prevention of infectious diseases, with primary emphasis on viral infections of the respiratory and enteric systems. I obtained my formal scientific training in virology with a concentration on the replication and pathogenesis of double-stranded RNA viruses using the mammalian reovirus model system. Subsequently, I studied structure-function relationships within reovirus replication factories that culminate in the production of infectious viral progeny and serve as post-entry determinants of viral host-cell tropism. The basic investigatory research was complemented by a suite of collaborative clinical studies addressing contemporary epidemiology, causation, pathobiology, and vaccine-mediated amelioration of acute respiratory illness and gastroenteritis, focusing particularly on rotavirus and influenza virus.

    My integrated interests in basic and applied virology found a home in the Denison Laboratory, where my recent work has focused on development of vaccines and antivirals against emerging coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Middle East respiratory syndrome coronavirus (MERS-CoV). Related work includes the contemporary pathogen spectrum and genetic diversity, clinical features, immune responses, and vaccine effectiveness associated with acute viral respiratory and gastrointestinal infections.

Research Staff


  • Samantha L Grimes

    Graduate Student
    Pathology, Microbiology and Immunology

    Samantha began her science journey as an NIH summer intern in 2016, where she worked under Dr. Rebekah Feng in the lab of Dr. Leorey Saligan to investigate the role of metabotropic glutamate receptors in Th17 inflammatory response. She then graduated from the University of Pittsburgh in 2019 with a B.S. in microbiology where she worked under Dr. Amanda Poholek to investigate the role of Blimp1 in Th2-mediated asthma. She joined the Vanderbilt IGP and subsequently, the Denison lab in 2020. Samantha's thesis project is defining the role of the coronavirus helicase in replication.

Postdoctoral Fellows