Adeno-associated virus capsid protein (AAV capsid) (AAV capsid)

The adeno-associated virus (AAV) capsid is a proteinaceous shell composed of 60 subunits of three structural proteins (VP1, VP2, and VP3) in a 1:1:10 ratio that encapsulates a single-stranded DNA genome (PMID: 29449657). In the context of biotechnology, the AAV capsid serves as the primary delivery vehicle for gene therapies, engineered to target specific tissues and protect the genetic payload from degradation (PMID: 31515536). Its biological function involves binding to cell surface receptors, such as the AAV receptor (AAVR) or heparan sulfate proteoglycans, and facilitating endosomal escape and nuclear entry (PMID: 26789245). While AAV is non-pathogenic, the capsid is a major target of the human immune system, leading to challenges such as pre-existing neutralizing antibodies that can render treatments ineffective (PMID: 30503243). Therapeutic strategies often involve engineering the capsid to enhance tissue tropism, reduce immunogenicity, or evade neutralizing antibodies (PMID: 31515536). Clinical monitoring of capsid-related safety is critical, as high-dose administration can trigger severe inflammatory responses, hepatotoxicity, or thrombotic microangiopathy (PMID: 33035222).

Other names

AAV VP1/VP2/VP3AAV shellViral protein assemblyAAV structural proteinAdeno-associated virus coat protein

The AAV capsid facilitates the delivery of therapeutic transgenes by binding to specific cellular receptors (such as AAVR), undergoing receptor-mediated endocytosis, and trafficking the genetic payload to the host cell nucleus for episomal expression (PMID: 29449657, PMID: 26789245).