Endogenous retroviruses (ERVs) are ubiquitous genomic parasites originating from ancient infectious retroviruses, and constitute 8% of the human genome. Large-scale genomic studies have revealed ERVs as majorsourceoftranscriptionalregulatoryelementsinmammaliancells,suggestiveofanextensiveroleindriving theevolutionofgeneregulatorynetworksinbothhealthanddisease.However,thespecificconsequencesand biologicalsignificanceofERVregulatoryactivityremainscontroversialandnotwellunderstood.Theproposed researchseekstoinvestigateemergingrolesforERVsin(1)theevolutionofimmuneregulatorynetworksand (2) gene dysregulation in cancer. First, we will investigate a potentially fundamental role for ERVs driving regulatory evolution of innate immune responses in mammals, through genome-wide epigenetic and transcriptionalprofilingoftheinterferonresponseincellsderivedfromdiversemammalianspecies.Thisworkis positioned to uncover a recurrent role for ERVs in regulating immune pathways, which may reveal pervasive underappreciated differences in immune responses across species. In a second line of research, we seek to investigatehowtheepigeneticderepressionofERVsincancercontributestopathologicalgeneexpression.The transcriptional reactivation of ERVs is a hallmark of many cancers, but their potential contribution todisease remains poorly understood. We will investigate how reactivated ERVs might cause widespread regulatory dysfunction as a global source of cancer-specific promoters, enhancers, and noncoding RNAs. Focusing on colorectalcancerasamodel,wewillrepurposepooledCRISPRscreeningtoinvestigatehowreactivatedERVs regulate phenotypes contributing to oncogenesis. Our interdisciplinary approach synthesizes functional genomics, genome engineering, evolution, and disease to form a comprehensive platform for deciphering the consequencesofERVsonmammalianbiology.

Public Health Relevance

Endogenousretrovirusesareremnantsofpastretroviralinfectionsandmakeup8%ofourgenomes.Thereis growingevidencethatthereactivationoftheseviralsequencesplaysanimportantroleinmanyhuman diseasesincludingcancerandautoimmunity.Thisproposalwillintegrategenomicanalysisandimmunological approachestoadvanceourunderstandingofhowtheseelementsimpactcellularfunctioninhealthand disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Unknown (R35)
Project #
1R35GM128822-01
Application #
9575487
Study Section
Special Emphasis Panel (ZGM1)
Program Officer
Sledjeski, Darren D
Project Start
2018-08-01
Project End
2023-07-31
Budget Start
2018-08-01
Budget End
2019-07-31
Support Year
1
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of Colorado at Boulder
Department
Miscellaneous
Type
Organized Research Units
DUNS #
007431505
City
Boulder
State
CO
Country
United States
Zip Code
80303