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.