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Walton, C. C.

Publications and source records attributed to Walton, C. C..

6 recordsLinked to original sources

In vitro comparison of Aβ-targeting SNIPR, synNotch, and TRUCK for cell-based drug delivery in Alzheimer's disease.

Pioneering research is adapting chimeric antigen receptors (CARs) from oncology to Alzheimers disease (AD) by targeting amyloid beta (A{beta}). Newer synthetic receptor systems can go beyond, transforming cells into targeted biological drug factories that can couple A{beta} detection to synthesis and secretion of genetically encoded therapeutics. Among candidate systems, T cells Redirected for Universal Cytokine Killing (TRUCK), synthetic Notch (synNotch), and Synthetic Intramembrane Proteolysis Receptors (SNIPR) have shown promise in oncology. Here, we adapt these platforms to AD using a shared A{beta}-targeting binding domain derived from Aducanumab (Aduhelm), coupled to inducible expression cassettes driving identical transgenes: secreted Metridia luciferase (MetLuc) and a Lecanemab (Leqembi)-based chimeric human-mouse antibody (chLecanemab). To validate these systems in vitro, Jurkat clones expressing each receptor were treated with oligomer-enriched A{beta} (A{beta}O) to model AD, and receptor output was quantified by media MetLuc levels and chLecanemab colocalization with A{beta} aggregates. For TRUCK systems, we show the A{beta}-targeting CAR successfully activated Jurkat cells by flow cytometry. We also show that six Nuclear Factor of Activated T-cells (NFAT) tandem repeat response elements (6xNFAT) paired with either minimal interleukin-2, synthetic TATA box, or minimal cytomegalovirus promoters resulted in functional regulatory regions. Despite this, all TRUCK variants failed to significantly upregulate MetLuc in response to A{beta}O. In contrast, both synNotch and SNIPR responded robustly to A{beta}O, with SNIPR outperforming synNotch in both MetLuc and chLecanemab production. These findings establish SNIPR and synNotch as promising platforms for future research on cell-based targeted therapeutic delivery in AD.

neuroscience↗

An Autophagy-Inducing Compound Reduces Tau Pathology, Microglia Reactivity, and Rescues Working Memory in 3xTg AD Mice

BackgroundRecent advancements in Alzheimers disease (AD) therapeutics have validated the use of amyloid beta (A{beta})-clearing antibodies, which reduce A{beta} pathology but leave other disease hallmarks largely unaddressed. Since AD involves multiple pathological processes, additional strategies are needed to target complementary mechanisms. One such target is autophagy, a lysosomal mediated degradation pathway essential for cellular homeostasis that removes toxic protein aggregates and damaged organelles. This process is implicated in AD, as impaired lysosomal function promotes A{beta} and tau accumulation. Our laboratory recently identified a novel natural mitophagy-inducing compound (MIC) that may serve as a therapeutic intervention for AD. MethodsWe evaluated the effects of MIC in aged 3xTgAD mice, a transgenic model displaying both A{beta} and tau pathology. Mice received either standard diet or diet containing MIC beginning at age 4 months until 20 months on alternating weeks. Age-matched non-transgenic (NonTg) controls were included under standard and MIC-supplemented diets to assess compound effects during normal aging. Neuropathological changes were assessed using immunohistochemistry (IHC) for A{beta}, phosphorylated tau (pTau), and microglial reactivity. Cognitive performance was evaluated using the Morris Water Maze (MWM) to assess spatial learning and memory and the Y-maze to measure working memory. ResultsAt 20 months of age, our neuropathological assessment showed that 3xTgAD mice fed an MIC-supplemented diet had a significant reduction in pTau accumulation and microglial reactivity, although A{beta} burden remained unchanged. At 15 months, MIC diet also improved spatial learning and memory in aged NonTg controls but not in 3xTgAD mice. However, in younger 8-month-old 3xTgAD mice, MIC restored working memory performance to NonTg levels, indicating an age-dependent therapeutic response. ConclusionMIC emerges as a potential modulator of tau pathology and neuroinflammation. As a naturally derived compound, MIC offers potential for combination therapy with FDA-approved A{beta}-clearing antibodies, enabling a multimodal approach to AD treatment that addresses amyloid, tau, and microglia-related pathology.

neuroscience↗

Chimeric Antigen Receptors Discriminate Between Tau and Distinct Amyloid-Beta Species

Abstract/SummaryThe lack of a definitive cure for Alzheimers disease (AD) is fueling the search for innovative therapeutic strategies. Having revolutionized cancer immunotherapy, immune cell engineering with chimeric antigen receptors (CAR) is being explored to target AD. Whether CARs can recognize distinct amyloid-{beta} (A{beta}) species and tau neurofibrillary tangles (NFTs)--hallmark pathologies of AD--remains unclear. To investigate this, we engineered CARs based on AD antibodies targeting tau (E2814), A{beta} (Lecanemab and Aducanumab), and truncated pyroglutamate form of A{beta} (A{beta}p3-42; Donanemab and Remternetug). To evaluate CAR function, we established the murine DO11.10 hybridoma T-cell line as a practical and scalable testing platform. Our findings demonstrate that CARs can detect and discriminate between tau preformed fibrils (PFFs), A{beta}1-42, and A{beta}p3-42 aggregates. This highlights the potential of repurposing AD antibodies for CAR-based therapies to selectively target tau NFTs and distinct forms of A{beta} senile plaques.

synthetic biology↗

A Human Neuron Alzheimer's Disease Model Reveals Barriers to Senolytic Translatability

Therapeutic successes in mouse models of Alzheimers disease (AD) largely fail to translate into clinical trials, with experimental drugs rarely validated in human models before being administered to humans. To address this, we developed an accessible method for long-term culture of commercially available primary human neurons and astrocytes, along with an amyloid-beta 1-42 (A{beta})-based in vitro AD model. Using this system, we evaluated two senolytic regimens previously shown to be effective in AD mouse models--Navitoclax and Dasatinib plus Quercetin (DQ)--and the natural killer cell line NK92 for emerging immune-mediated senescent cell ablation therapies. NK92 cells preferentially--but not exclusively--targeted A{beta}-treated neurons and astrocytes with senescent-like phenotypes. DQ demonstrated a safe profile for human neurons, but Navitoclax exhibited non-selective neurotoxicity. These findings highlight risks of Navitoclax and NK-based interventions and underscore the critical need for human-relevant models in the AD drug-development pipeline to improve safety and clinical translatability.

neuroscience↗

Aβ-targeting synNotch Receptor for Alzheimer's Disease: Expanding Applications to Extracellular Protein Aggregates

The synthetic Notch receptor (synNotch) system is a versatile platform that induces gene transcription in response to extracellular signals. However, its application has been largely confined to membrane-bound targets due to specific activation requirements. Whether synNotch can also target extracellular protein aggregates, such as amyloid beta (A{beta}) in Alzheimers disease (AD), is unclear. To address this, we engineered an A{beta}-targeting synNotch receptor controlling the production of chimeric human-mouse versions of Lecanemab (Leqembi(R)) or Aducanumab (Aduhelm(R)), both FDA-approved antibodies for AD. We demonstrate that NIH 3T3 cells expressing this synNotch system detect and respond to extracellular A{beta} aggregates by synthesizing and secreting Aducanumab or Lecanemab. These findings broaden the potential applications of synNotch, extending its targets beyond membrane-bound proteins to extracellular protein aggregates, providing obvious benefits to research in this scientific arena.

synthetic biology↗

Checkpoint signaling abrogation after cell cycle reentry reveals that differentiated neurons are mitotic cells

Mitotic activity associated to neuron cell-death instead of cell-division is reported in neurodegenerative diseases. However, why mitotic activity can take place in supposedly postmitotic neurons and how it is associated to cell-death remains largely unexplained. To address these questions, we have studied the response of primary neurons to oncogenic deregulation using a fusion protein based on truncated Cyclin E and Cdk2. Oncogenic Cyclin E/Cdk2 elicits mitotic checkpoint signaling, resulting in cell-cycle arrest and cell-death. However, as in mitotic cells, checkpoint suppression enables oncogenic cell-cycle progression and neuronal division. Further, neurons actively adapt to the cell-cycle by losing and reforming the axon initial segment, which integrates synaptic inputs to sustain action potentials. We conclude that neurons are mitotic cells in a reversible quiescent-like state, which is falsely portrayed as irreversible by mitotic checkpoints. In extension, neuronal death in lieu of cell-division reflects oncosuppressive checkpoint signaling.

neuroscience↗