Conserved Immune Response to Sensing Cytosolic DNA
Project Summary/Abstract:
Candidate: Throughout my scientific career I have been involved in the study of host-pathogen interactions,
with an emphasis on bioengineering, microbiology, immunology, and vaccine development. Training in
virology, molecular biology, and computational methods has helped me answer a wide variety of scientific
questions. The project proposed here is designed to bridge my transition from a postdoctoral fellow to an
independent investigator in an academic setting to continue my pursuit of using creative approaches to high-
impact, adventurous research to understand the host response to pathogenic infection.
Research: Innate immunity refers to the body's initial response to curb infection upon exposure to invading
organisms. While the detection of pathogen-associated molecules is an ancient form of host defense, if
dysfunctional, it can cause autoimmune disease, which affects over 20 million Americans. The innate immune
response is the first line of defense to microbial infection, and it is initiated through the activation of receptors
recognizing conserved molecules that are signature of pathogenic infection. Recently, STING (STimulator of
INterferon Genes), an intracellular sensor of cytosolic DNA was discovered. STING is critical to the innate
immune response during viral and bacterial infection, yet animals exhibiting STING hyperactivation at birth
display inflammatory autoimmune disease. While the downstream signaling events occurring after STING
activation are well understood, little is known about the mechanisms responsible for STING activation. To
address this question, I propose an orthogonal approach utilizing Drosophila melanogaster to
investigate STING function and the molecules that stimulate it. This approach will complement the
ongoing studies of STING in a mammalian system. In Aim 1, we will determine how human STING and
Drosophila STING (dSTING) are similar, providing evidence that dSTING is the bone fide ancestor of human
STING. We will assess the capacity of dSTING to bind nucleic acids and characterize the domains of dSTING
to determine which are critical for nucleic acid binding and intracellular localization. In Aim 2, we will create a
dSTING knockout fly to study the role of dSTING in the innate immune response to infection. Gene expression
analyses will be used to functionally determine how the loss of dSTING contributes to an impaired innate
immune response, as compared to that of a genomic rescue fly. Aim 3 will utilize next-generation sequencing
to identify the nucleic acids that bind to dSTING during microbial infection, providing insight to the specificity of
the ligand for STING, a site for potential therapeutic intervention. Together, these studies using the genetically
malleable Drosophila model system will improve our understanding of STING function through the
extrapolation of the results into the mammalian system for further experimentation. The information gained in
this study will have broad-ranging impacts in innate and autoimmunity towards to the development of
therapeutics to treat microbial infection and autoimmune disorders.
Environment: This project complements the ongoing research on innate immunity of my proposed mentor, Dr.
Glen Barber. The work will also setup new collaborations with my co-mentor, Dr. Grace Zhai. Both mentors
will provide invaluable mentorship throughout the K99 phase of the award, giving me the training necessary for
the rise to independence. The University of Miami has superb facilities, equipment, and outstanding faculty
who study microbiology and immunology, through the use of exciting techniques and animal models.