PROJECT SUMMARY/ABSTRACT
The gut microbiota produces a myriad of metabolites that have been shown to have wide effects on host
biology. Specifically, peptidoglycan (PG) fragments are well established immunomodulators in many health
issues including inflammatory diseases, microbial infections, and cancers and have been shown to be
translationally relevant in immune cell differentiation, insulin processing, and the efficacy of checkpoint inhibitor
immunotherapies. Although the microbiota’s ability to produce PG fragments may provide an underlying
mechanism for host-microbial interactions, it remains difficult to selectively modulate the amount of host-available
PG. Therefore, the development of new tools to upregulate PG fragments in circulation for gain of
function studies are needed to understand certain fundamental host biologies. Previous efforts to decipher
these signaling pathways have focused the phylogenetic relationships of correlated microbes rather than their
shared metabolic outputs; however, these genomic data do not provide information on protein secretion levels,
stability, or activity. Unlike previous work, this proposal will directly assay microbial enzymes through a
chemoproteomic platform to uncover functional PG-degrading enzymes for the development of functionalized
probiotics to control metabolite output in host systems.
It is hypothesized that increased hydrolytic activity in the gut will selectively control PG fragment levels in
circulation. The proposal’s main goals are to identify highly active, secreted, and stable PG-degrading enzymes
(Aim 1) and to genetically engineer tools to upregulate PG metabolites in circulation (Aim 2). This research will
allow for the discovery of high performing microbial enzymes to rationally control circulating glycan metabolites
through gut colonization with engineered tool organisms. The potential discoveries in this proposal could be
translationally applied to alter microbe-human dynamics through the utilization of mechanistically-defined
probiotics.
The Sponsor, Co-Sponsor and PI have developed a fellowship training plan that will enable the PI’s future
goal of becoming an independent researcher through enhancing both her scientific expertise and professional
skills. To accomplish the experimental aims as proposed, the PI will receive training in proteomics, probiotic
genomic engineering, and animal handling. In addition, the training plan outlines key professional development
events that will improve the PI’s scientific communication and writing abilities, which will enable a successful
career trajectory for her. This research plan will ultimately develop the PI’s scientific and professional
proficiencies so that she may obtain a post-doctoral research position, which will lead her toward
becoming an independent scientist. The expertise that will be gained through her experimental work on this
proposal as well as her participation in the didactic and career development activities planned will enable the PI
to accrue the tools needed to have a successful career as a future independent researcher.