Immunosenescence as a modifiable driver of neurodegenerative diseases: Pathways and multidimensional emerging strategies for Alzheimer's and Parkinson's diseases.

Immunosenescence represents a core upstream driver of Alzheimer's disease (AD) and Parkinson's disease (PD), exerting its pathological effects through four mechanistically interconnected cascades: chronic inflammatory imbalance mediated by the senescence-associated secretory phenotype (SASP), oxidative stress arising from immune-metabolic reprogramming, protein homeostasis dysfunction caused by autophagy-lysosomal failure, and disrupted neuro-immune crosstalk secondary to breakdown of central nervous system (CNS) immune privilege. Current clinical practice remains largely constrained to neurotransmitter-based symptomatic management, which can neither arrest upstream pathological progression nor restore lost neuronal populations. Emerging intervention strategies targeting immunosenescence, including senolytic agents, antioxidant and metabolic modulators, autophagy restoration, and precision-targeted nanocarrier delivery, have demonstrated substantial capacity to delay disease progression in preclinical and early clinical investigations. These strategies act through selective clearance of senescent immune cells, remodeling of the neuroinflammatory microenvironment, and restoration of cellular quality-control mechanisms. The multidimensional treatment strategy approaches from the perspectives of artificial intelligence (AI) guided target discovery, nanocarrier engineering, and gut microbiota intervention to simultaneously address multiple nodes in the immunosenescence network, thereby overcoming the inherent limitations of single-target strategies. This review consolidates current mechanistic evidence and translational data to establish immunosenescence as an actionable therapeutic target and to provide a conceptual framework for precision disease-modifying therapy in AD and PD.