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NIH grant 1K99AG103879-01: Elucidating determinants of LINE-1-mediated inflammaging
Institute: {'code': 'AG', 'abbreviation': 'NIA', 'name': 'National Institute on Aging', 'admin_org_id': '12500002', 'admin_funding_url': ''}. PI: TREVOR VAN EEUWEN. Award: $141210.
Start: 2026-09-11T00:00:00.
PROJECT SUMMARY/ABSTRACT
Retrotransposable elements (RTEs), genetic sequences capable of “copy-and-paste” self-replication, comprise
approximately 40% of the human genome, with Long INterspersed Element 1 (LINE-1/L1) representing the
largest and most active class of RTEs. RTEs are typically suppressed in healthy tissues by several mechanisms
but as cells reach senescence they ultimately lose control over their RTEs which has been correlated with
interferon (IFN) type-I production. I have found that L1 expressed in cells can produce cytoplasmic DNA:RNA
hybrids that have the potential to behave like pathogen-associated molecular patterns (PAMPs) that stimulate
pattern recognition receptors (PRRs) and stimulate innate immune signaling. This is consistent with previous
work that has linked senescence associated L1 de-repression with IFN signaling. These data strongly indicate
that L1 directly stimulates innate immunity in senescent cells by generating cytoplasmic PAMPS and this is a
fundamental process in cellular aging. During the mentored phase of this proposal, I will gain new training in
bioinformatics and the cell biology of aging to address what cell-derived nucleic acids stimulate IFN generation
by L1 in senescent cells. In Aim 1, I will determine the sequence characteristics and identities of PAMPs
generated by L1 in vitro and co-purified with RNPs from cells expressing L1 and cross reference them with
nucleic acids co-purified with PRRs, particularly cGAS, to identify immunostimulatory nucleic acid species. I will
also determine the structure of L1 synthesizing PAMPs through ‘snapback’ priming to determine the structural
adaptations that facilitate this novel activity. In Aim 2, I will establish a direct, causal link between L1 activation,
generation of viral mimicking PAMPs, cGAS/STING activation and IFN response in senescent cells. Additionally,
I will use a candidate gene approach along with genome-wide CRISPR screening to characterize and identify
genes that regulate the L1-mediated IFN response. In Aim 3, I will take full advantage of my K99 training and
determine the how host factors physically interact with cytoplasmic behavior of L1 RNPs stimulate innate
immunity. Specifically, I will use compartment-targeted affinity proteomics, bimolecular fluorescence
complementation and in cellulo structural methods to determine how host factors interact with L1 RNPs and how
this ultimately leads to senescence associated inflammation. In the short term, the proposed new training (Aims
1 and 2) by my expert mentors and mentorship committee, along with complementary formal coursework, will
provide a foundation on which I can continue to investigate in my independent laboratory the (Aim 3). The
exceptional training environment in the Rout & Greenbaum laboratories and at Rockefeller University will greatly
facilitate the mentored research and will endow me with the necessary professional training and experimental
skills to transition to an independent faculty position. The proposed work will establish a mechanistic basis for
the role of RTEs in senescence associated inflammation and its regulators. My ultimate goal is to leverage this
mechanistic understanding to investigate RTEs in age related disease models in my independent lab.document fetched 2026-09-20 02:42