G2 - Immune Targeting and Approaches with Genetically-Modified Cells and Cell Therapies (Including CAR-T, CAR-NK, TCR editing)
186: T-Cell Epigenetic Reprogramming with TGIF2LX-Overexpression Enhances Adoptive Cell Therapy
Type: Oral Abstract Session
Presentation Details
Session Title: CAR T-cell Therapies
Memory T-cells exhibit distinct functional characteristics depending on their location within the body. Recent advancements have unveiled a significant population of memory T-cells residing in non-lymphoid tissues. These resident memory T-cells are critical for combating infections and their abundance has a positive correlation with improved survival rates across many solid tumor types. Motivated by this observation, we aimed to harness the potential of resident memory T-cells for adoptive cell therapy. However, isolating these cells from donor-derived tissues is impractical. Therefore, we focused on epigenetic reprogramming of blood-derived T-cells towards a tissue resident state. We conducted two cDNA overexpression screens, using open reading frames (ORFs) encoding all known transcription factors, in human primary CD8 T-cells to identify genetic regulators of CD103 (a residency marker) and IL7R (a memory marker). The intersection of these screens identified the transcription factor TGIF2LX, capable of upregulating both markers. Interestingly, this transcription factor is only expressed in male reproductive tissues, although other TGIF family members have been implicated in T-cell function. Bulk RNA-sequencing revealed that TGIF2LX overexpression in T-cells leads to widespread transcriptional reprogramming, including activation of genes associated with increased tissue residency programs (e.g. ITGAE, CD69, CXCR6) and decreases in genes associated with circulation programs (e.g. KLF2, S1PR1). We further characterized TGIF2LX-overexpressing T-cells using a multimodal single cell readout, pairing scRNA-seq with a CITE-seq library of 134 unique cell surface markers. This demonstrated a distinct cell state with TGIFL2X-overexpressing T-cells existing in clusters unique from those containing unenhanced cells. Of note, these cells also clustered separately from T-cells overexpressing RUNX3, a transcription factor previously identified to enhance tissue residency and improve tumor control, suggesting a novel axis for controlling tissue residency. We tested the effect of TGIF2LX overexpression in modulating CAR-T efficacy in a human breast cancer xenograft model. HCC1954 breast cancer cells were implanted orthotopically into the mammary fat of NSG mice. After 10 days, HER2-targeting CAR-T cells were administered intravenously at a subcurative dose (5x10^5 cells). TGIF2LX-overexpression dramatically improved tumor control by CAR-T cells relative to unmodified control and RUNX3-overexpressing CAR-Ts. These data provide proof-of-concept of a novel strategy for enhancing adoptive cell therapies for solid tumors.
Tomer Rotstein1, Mike Brown2, Sean McCutcheon3, Charles A. Gersbach4
1Biomedical Engineering, Duke University, Durham, NC,2Neurosurgery, Duke University, Durham, NC,3Duke University, Apex, NC,4Duke University, Durham, NC"
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