Hypothesis

Intermittent, tissue‑specific CRISPR‑activation of the telomerase reverse transcriptase (TERT) promoter, combined with transient, c‑Myc‑free expression of Yamanaka factors (OSK), will improve multiple hallmarks of aging in humans without increasing tumorigenic risk when delivery is limited to non‑integrating AAV vectors and dosing is restricted to quarterly pulses.

Mechanistic Rationale

1. Telomerase activation mitigates replicative senescence – Mice treated with AAV‑TERT show median lifespan extension of ~41% and improved aging biomarkers without observable cancers {1}. Maintaining telomere length reduces DNA‑damage foci at chromosome ends, lowering the activation of the cGAS‑STING pathway and downstream SASP production.

2. Transient epigenetic rejuvenation resets the aging clock – Cyclic expression of OSKM (excluding c‑Myc) reverses epigenetic age markers in mice while avoiding tumorigenesis {2}. The transient nature limits the window during which pluripotency‑associated oncogenic programs could be engaged.

3. Synergy reduces inflammasome activation – Telomere stabilization diminishes cytosolic DNA that can activate NLRP3 inflammasome, while OSK‑mediated chromatin opening enhances expression of antioxidant genes (e.g., SOD2, CAT) {5}. Combined, these effects lower chronic inflammation, a central driver of age‑related pathology.

4. Safety via inducible, non‑integrating delivery – Using AAV vectors with a doxycycline‑inducible promoter allows precise temporal control; the episomal genome diminishes insertional mutagenesis risk, and the 15‑year follow‑up requirement for approved gene therapies {6} provides a framework for long‑term surveillance.

Testable Predictions

• Primary endpoint: After 24 months of quarterly dosing, participants aged 65‑80 will show a statistically significant increase in leukocyte telomere length (≥0.5 kb) compared with placebo {9}.
• Secondary endpoints: Reduction in plasma SASP factors (IL‑6, TNF‑α) by ≥30%; improvement in epigenetic age clocks (e.g., Horvath) by ≥2 years; no increase in clonal hematopoiesis of indeterminate potential (CHIP) variants or incidence of malignancies versus control.
• Safety endpoints: No dose‑limiting toxicities, no anti‑AAV neutralizing antibody titers >1:200 that impede re‑dosing, and no evidence of replication‑competent vector in blood or urine.

Experimental Design (Phase I/II)

• Population: 120 healthy older adults (60 treatment, 60 placebo), stratified by sex and baseline telomere length.
• Intervention: AAV9‑TERT‑dCas9‑VPR (CRISPRa) plus AAV9‑OSK (c‑Myc‑free) under a Tet‑ON system; participants receive doxycycline 100 mg orally for 3 days every 3 months.
• Controls: Placebo AAV vector with same inducible cassette but no active transgenes.
• Follow‑up: Comprehensive assessment at baseline, 3 mo, 6 mo, 12 mo, 18 mo, and 24 mo, including qPCR telomere length, plasma proteomics, epigenetic methylation array, CBC with CHIP screening, MRI for organ toxicity, and adverse event monitoring.

Falsifiability

If, after two years, the treatment group does not demonstrate a significant telomere lengthening or epigenetic age reversal, or if there is a measurable rise in CHIP‑associated mutations or neoplastic events, the hypothesis would be falsified. Conversely, meeting the predefined efficacy and safety thresholds would support the feasibility of controlled, intermittent gene‑based anti‑aging interventions and provide a regulatory pathway distinct from unregulated DIY CRISPR attempts.