IF a GK-NaV multi-valent nanovaccine co-delivering GPNMB extracellular domain peptide and uPAR (PLAUR) extracellular domain peptide at a 1:2 molar ratio (uPAR-biased to prevent GPNMB immunodominance), formulated with R848 (TLR7/8 agonist) and GM-CSF and administered subcutaneously to 18-month-old male and female C57BL/6J mice (3-dose primary series, weeks 0/3/6, plus a single boost at month 3), is co-administered concurrently with a low-dose, intermittent oral senolytic sensitizer targeting Senescent Cell Anti-Apoptotic Pathways (SCAPs — specifically BCL-2/BCL-XL as identified by transcriptomic network analysis),

THEN compared to either the dual-antigen vaccine alone, SCAP inhibition alone, or single-antigen vaccines (GPNMB-only or uPAR-only), the combination arm will demonstrate: (a) ≥50% reduction in GPNMB+ senescent cell burden in visceral adipose and aortic endothelium by IHC at 12 weeks post-vaccination; (b) ≥50% reduction in uPAR+ senescent cell burden in liver (pericentral zone), lung interstitium, and skeletal muscle by IHC; (c) ≥40% reduction in composite SASP plasma panel (IL-6, MMP-3, GDF-15, PAI-1); and (d) statistically significant improvements in grip strength, treadmill endurance, and metabolic parameters (glucose tolerance, body composition) versus all monotherapy controls, measured at 12 and 24 weeks post-treatment initiation,

BECAUSE of the following causal chain:

1. GPNMB+ and uPAR+ senescent cell populations are largely non-overlapping by tissue and induction context. uPAR is broadly induced across senescent cell types linked to ECM remodeling and the coagulation cascade, with eight transcripts fulfilling broad senescence-expression criteria and uPAR prioritized as the highest-confidence candidate surface antigen (uPAR identified as broadly senescence-induced surface protein)[https://doi.org/10.1038/s41586-020-2403-9]. GPNMB, by contrast, is enriched on vascular endothelial and adipose senescent cells as established by the Suda/Minamino GPNMB vaccine work (discussed in Literature Task Output). Because these two populations are largely distinct, a monovalent vaccine targeting either antigen alone leaves a large fraction of the total senescent cell burden intact — a gap that dual-antigen co-delivery is uniquely positioned to address.

2. Multi-valent nanoparticle co-delivery maintains immunogenicity for both antigens. Cancer neoantigen vaccine research demonstrates that co-loading two or more peptide epitopes onto the same nanoparticle ensures simultaneous uptake by a single dendritic cell, preventing antigenic competition (discussed in Literature Task Output, citing Kuai et al., Nature Materials 2017). The uPAR-biased 1:2 ratio is selected because uPAR peptides may be less immunogenic in self-antigen contexts and because GPNMB carries constitutive expression on non-senescent macrophages and melanocytes that could more readily trigger peripheral tolerance, making a higher GPNMB dose counterproductive. [SPECULATIVE —...

SENS category: GlycoSENS

Key references: • doi.org/10.1038/s41586-020-2403-9]. • doi.org/10.1101/2024.05.28.596326]. • doi.org/10.3390/biom11030467]. • doi.org/10.1038/s41586-020-2403-9 • doi.org/10.1101/2024.05.28.596326