This study comprehensively delineates a novel pathological pathway through which somatic mutations mediate Alzheimer's disease (AD) pathology, overturning the conventional understanding that AD is driven solely by the accumulation of single protein species. Age-related decline in hematopoietic stem cell function leads to the accumulation of clonal hematopoiesis‑related cancer driver mutations, such as in TET2 and ASXL1. Peripheral monocytes carrying these mutations can infiltrate the brain parenchyma through the age‑impaired blood–brain barrier and subsequently differentiate into microglia‑like macrophages (MLBMs). These MLBMs serve as the primary cellular reservoirs for the accumulated mutations. Through epigenetic remodeling, the mutations induce MLBMs to transform into a pro‑inflammatory DAM (disease‑associated microglia) phenotype. In synergy with mosaic chromosomal alterations, this transformation further activates a pro‑inflammatory transcriptional program within the cells.

Pathological products in the brain, such as amyloid‑β (Aβ) and hyperphosphorylated tau, exert clonal selection pressure that drives the continuous proliferation and expansion of mutated cells. These expanded mutant cells release large amounts of inflammatory cytokines, triggering a cascade of neuroinflammation that gradually leads to synaptic damage and neuronal apoptosis. These findings firmly link somatic mutations, clonal expansion, and neurodegeneration, and position mutated proteins and activated MLBMs as innovative therapeutic targets for Alzheimer's disease.

MLBMs (microglia‑like brain macrophages) serve as the central hub linking peripheral clonal hematopoiesis with intracerebral neuroinflammation. This study confirms that MLBMs are the primary cellular reservoirs for somatic mutations. Compared with traditional targets such as Aβ and tau, MLBMs offer unique value for drug discovery. Somatic mutations continuously drive MLBMs to maintain an aberrantly activated state, while also inducing metabolic reprogramming and unlimited proliferation. These changes are direct drivers of persistent chronic neuroinflammation. Targeting MLBMs can interrupt the AD pathological cascade at an upstream step, providing a clearer rationale for intervention.

However, the presence of the blood–brain barrier (BBB) greatly complicates the development of brain‑targeting drugs, with poor penetration of large molecules representing a critical bottleneck. As a result, specific antibodies, VHH nanobodies, and targeting peptides have become mainstream research directions. Leveraging its established platforms such as phage display and peptide library screening, Alpha Lifetech offers targeted screening against MLBMs surface markers and intracellular mutant proteins, together with supporting services for recombinant protein production and activity assays. This provides comprehensive technical support for the discovery of AD drug candidates targeting MLBMs.

Phage display is currently a mainstream technology platform for developing AD‑targeting molecules. Its greatest advantage lies in its high‑diversity library systems, which enable the construction of fully human antibody libraries, VHH nanobody libraries, and other types of libraries. This allows efficient recognition of structurally complex and challenging AD targets such as mutant proteins and membrane proteins. The platform employs a high‑throughput in vitro enrichment mode; multiple rounds of panning rapidly enrich specific positive clones, resulting in a short overall development cycle. The obtained antibodies exhibit affinities in the nM to pM range, fully meeting the performance requirements for both research and drug development.

Addressing the challenge of brain delivery in AD, VHH nanobodies selected from the platform are small in size and compact in structure, offering excellent BBB penetration, lower immunogenicity, and better safety profiles for in vivo applications. Alpha Lifetech provides a one‑stop service covering antigen preparation, library panning, positive clone identification, and antibody engineering. Customized screening strategies can be tailored to the physicochemical properties of AD targets, significantly reducing development difficulty and shortening project timelines.

Peptide molecules are widely used in AD research due to their small molecular weight, straightforward synthesis, low immunogenicity, and high tissue penetration. At the basic research level, screening using random or directed peptide libraries can yield specific peptides targeting mutant proteins or activated microglia. These peptides can serve as molecular probes for target tracing, cell labeling, and protein‑protein interaction analysis, thereby facilitating in‑depth dissection of AD pathogenesis. In drug discovery, active peptides obtained from screening can be used directly as lead compounds or as targeted delivery vehicles to help drugs cross the blood–brain barrier and act on brain lesions.

Given the newly identified targets from this study—such as CHIP‑associated mutated genes and DAM cell markers—peptide library screening can rapidly generate a diverse range of candidate molecules. Alpha Lifetech has established a standardized peptide library screening platform that flexibly accommodates both solid‑phase and solution‑phase screening strategies. Combined with comprehensive activity validation assays, we evaluate the specificity and stability of the selected peptides, fully covering the needs of AD basic research, diagnostic reagent development, and innovative drug discovery.

Leveraging the novel targets uncovered in this study—such as somatic mutations and activated MLBMs—a multi‑platform, full‑chain R&D system can be established. At the initial stage, the recombinant protein platform is used to express, purify, and functionally validate target proteins, confirming their druggability potential. Subsequently, a flexible technical route is chosen based on the research goals. The phage display platform is employed to screen antibodies and VHH nanobodies, while peptide library and aptamer screening technologies are used to obtain diverse types of lead molecules, enriching the candidate molecule pool.

After obtaining initially positive hits, molecules undergo sequential evaluation of specificity, affinity, and stability. Molecular engineering is applied to optimize drug‑like properties. Cellular models are then established to validate the effects of the molecules on microglial activation and inflammatory cytokine secretion, completing in vitro pharmacological activity assessment. Alpha Lifetech integrates its suite of technology platforms—recombinant protein production, phage display, peptide library, and aptamer screening—to provide customized end‑to‑end R&D solutions. We streamline the entire workflow from target validation and molecule screening to functional evaluation, efficiently translating discoveries on novel AD targets into preclinical research.