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Biology subjects

Corey, D.

Publications and source records attributed to Corey, D..

4 recordsLinked to original sources

Modulation of TTR Gene Expression in the Eye using Modified Duplex RNAs

Small interfering RNAs (siRNAs) are a proven therapeutic approach for controlling gene expression in the liver. Expanding the clinical potential of RNA interference (RNAi) requires developing strategies to enhance delivery to extra-hepatic tissues. In this study we examine inhibiting transthyretin (TRR) gene expression by short interfering RNAs (siRNAs) in the eye. Anti-TTR siRNAs have been developed as successful drugs to treat TTR amyloidosis. When administered systemically, anti-TTR siRNAs alleviate symptoms by blocking TTR expression in the liver. However, TTR amyloidosis also affects the eye, suggesting a need for reducing ocular TTR gene expression. Here, we demonstrate that C5 and 2-O-linked lipid-modified siRNAs formulated in saline can inhibit TTR expression in the eye when administered locally by intravitreal (IVT) injection. Modeling suggests that length and accessibility of the lipid chains contributes to in vivo silencing. GalNAc modified anti-dsRNAs also inhibit TTR expression, albeit less potently. These data support lipid modified siRNAs as an approach to treating the ocular consequences of TTR amyloidosis. Inhibition of TTR expression throughout the eye demonstrates that lipid-siRNA conjugates have the potential to be a versatile platform for ocular drug discovery. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=84 SRC="FIGDIR/small/642595v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@1e9ad27org.highwire.dtl.DTLVardef@67067borg.highwire.dtl.DTLVardef@1da7eadorg.highwire.dtl.DTLVardef@1b2a552_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

Therapeutic Targeting of TIM-4-L With Engineered T Cells for Acute Myeloid Leukemia

Disruption of the lipid asymmetric bilayer is a common feature observed in cancer cells. We utilized the natural immune receptor TIM-4 to interrogate for loss of plasma membrane phospholipid polarity in primary acute myelogenous leukemia (AML) samples. We performed FACs analysis in 33 patients and correlated TIM-4-L expression frequency and intensity with molecular disease characteristics. In normal tissues, TIM-4-L is confined to the internal leaflet of the plasma membrane. By contrast, 86% of untreated AML blasts in our analysis displayed upregulation of cell surface TIM-4-L. These observations were agnostic to AML genetic classification, as samples with mutations in TP53, ASXL1, and RUNX1, also displayed TIM-4-L upregulation similar to that seen in favorable and intermediate subtypes. This TIM-4-L dysregulation was also stably present in both Kasumi-1 and MV-4-11 AML cell lines. To evaluate the potential of upregulated TIM-4-L to serve as a target for adoptive T cell therapy (ACT), we constructed TIM-4-L-directed engineered T cells, which demonstrated potent anti-leukemic effects, effectively eliminating AML cell lines both in vitro and in vivo. This approach led to the eradication of AML cells across a range of endogenous TIM-4-L expression levels. These results highlight TIM-4-L as a highly prevalent and novel target for T cell-based therapy in AML. Further investigations into the role of TIM-4-L in AML pathogenesis and its potential as an anti-leukemic target for clinical development are warranted.

cancer biology↗

Novel engineered chimeric engulfment receptors trigger T-cell effector functions against SIV infected CD4+ T cells

Adoptive therapy with genetically engineered T cells offers potential for infectious disease treatment in immunocompromised persons. HIV/simian immunodeficiency virus (SIV) infected cells express phosphatidylserine (PS) early post-infection. We tested whether chimeric engulfment receptor (CER) T cells designed to recognize PS-expressing cells could eliminate SIV infected cells. Lentiviral CER constructs comprised of the extracellular domain of T-cell immunoglobulin and mucin domain containing 4 (TIM-4), the PS receptor, and engulfment signaling domains were transduced into primary rhesus macaque (RM) T cells. We measured PS binding and T-cell engulfment of RM CD4+ T cells infected with SIV expressing GFP. As chimeric antigen receptor (CAR) T cells induce PS and subsequent TIM-4 binding, we evaluated in vitro killing of CAR and CER T-cell combinations. We found that recombinant TIM-4 bound to SIV infected cells. In vitro, CER CD4+ T cells effectively killed SIV infected cells, which was dependent on TIM-4 binding to PS. Enhanced killing of SIV infected CD4+ T cells by CER and CAR T-cell combinations was observed. This installation of innate immune functions into T cells presents an opportunity to enhance elimination of SIV infected cells and offers potential to augment functional cure of SIV/HIV infection.

immunology↗

Analyzing Presymptomatic Tissue to Gain Insights into the Molecular and Mechanistic Origins of Late-Onset Degenerative Trinucleotide Repeat Disease

How genetic defects trigger the molecular changes that cause late-onset disease is important for understanding disease progression and therapeutic development. Fuchs endothelial corneal dystrophy (FECD) is an RNA-mediated disease caused by a trinucleotide CUG expansion in an intron within the TCF4 gene. The mutant intronic CUG RNA is present at 1-2 copies per cell, posing a challenge to understand how a rare RNA can cause disease. Late-onset FECD is a uniquely advantageous model for studying how RNA triggers disease because; 1) Affected tissue is routinely removed during surgery; 2) The expanded CUG mutation is one of the most prevalent disease-causing mutations, making it possible to obtain pre-symptomatic tissue from eye bank donors to probe how gene expression changes precede disease; and 3) The affected tissue is a homogeneous single cell monolayer, facilitating accurate transcriptome analysis. Here we use RNA sequencing (RNAseq) to compare tissue from individuals who are pre-symptomatic (Pre_S) to tissue from patients with late stage FECD (FECD_REP). The abundance of mutant repeat intronic RNA in Pre_S and FECD_REP tissue is elevated due to increased half-life in a corneal cell-specific manner. In Pre_S tissue, changes in splicing and extracellular matrix gene expression foreshadow the changes observed in advanced disease and predict the activation of the fibrosis pathway and immune system seen in late-stage patients. The absolute magnitude of splicing changes is similar in presymptomatic and late stage tissue. Our data identify gene candidates for early drivers of disease and biomarkers that may represent diagnostic and therapeutic targets for FECD. We conclude that changes in alternative splicing and gene expression are observable decades prior to the diagnosis of late-onset trinucleotide repeat disease.

molecular biology↗