PROJECT SUMMARY
Commensal microbes are indispensable for healthy physiology of their eukaryotic hosts and provide
essential functions required for host survival, including nutrition and colonization resistance, and perform
accessory functions, including immune system development, vascularization, and contribute to behavior.
Composition of the microbiome is shaped by many factors. Some influences are acute, such as diet and
infection, which rapidly change the commensal population, but it returns to its pre-challenge composition. On
the other hand, the genetics of the host have a constant influence on the microbial composition. While
increasing pieces of evidence point to host genetics playing a critical role in shaping the microbiome, how it
does so is adversely understudied. To eliminate the influence of environmental factors and study only the role
of host genetics in shaping the microbiome, a murine model of legacy-independent host-commensal
interactions was developed. This model provided the foundational blueprint establishing that the microbiome is
impacted by host mechanisms, but how they are impacted has to be investigated.
Herein, we describe how we developing this model to dissect the role of host genetics in specific host-
commensal interactions. We have identified that the population of Lactobacillus murinus, a prominent member
of the gut microbiome, is directly shaped by host genetics. Through an interdisciplinary approach spanning
immunology, microbiology, and genetics, we will determine the mechanism directly influencing the intestinal
population of Lactobacilli. The proposed experiments will provide an experimental platform by which any host-
commensal relationship driven by host genetics can be identified and the mechanism can be determined.
Drs. Golovkina and Chervonsky are ideal sponsor and co-sponsor, respectively, for this project. Not
only did they establish the legacy-independent host-commensal model, but they are also experts in the fields of
microbiology, immunology, and genetics. Dr. Golovkina is a mouse geneticist who has built her career on using
inbred mouse strains to identify genes driving phenotypic differences in host-pathogen interactions and co-
established the field of microbiome-virus pathogen interactions. Dr. Chervonsky is a renowned immunologist
and expert in host-commensal interactions and the influence of the microbiome on autoimmunity. He is also
the co-director of the Gnotobiotic Component of the Host-Microbe Core at the University of Chicago. Their
laboratories are uniquely situated to support my efforts to study the gnotobiotic models necessary to delineate
host-commensal interactions through rigorous genetic studies.
They are dedicated mentors to my academic, scientific career at the bench and beyond. All necessary
resources to conduct the proposed experiments are found either in the labs already or on campus at the
University of Chicago. In addition to having many resources available for scientific use, the University of
Chicago is a fantastic training center for postdoctoral trainees.