Adenovirus serotype 5 capsid (PeptiCRAd-1 platform) (Ad5 capsid)

The PeptiCRAd-1 viral capsid refers to the structural shell of the modified Adenovirus Serotype 5 (Ad5) used in the PeptiCRAd (Peptide-coated Conditionally Replicating Adenovirus) technology platform (Capasso et al., 2016, OncoImmunology). This platform is designed to combine the oncolytic properties of adenoviruses with the specificity of peptide-based cancer vaccines (Ylosmaki et al., 2018, Molecular Therapy). The capsid is typically modified with a D24 deletion in the E1A region for tumor-selective replication and may incorporate CpG islands to enhance its immunogenicity (Valo Therapeutics, 2024). In the PeptiCRAd system, the negatively charged viral capsid is coated with positively charged tumor-specific peptides through electrostatic interactions, allowing the virus to act as a carrier that delivers these antigens directly to the tumor microenvironment (Capasso et al., 2016, OncoImmunology). Biologically, the capsid functions to protect the viral genome and mediate cell entry via the Coxsackie and Adenovirus Receptor (CAR). In the context of cancer therapy, it serves a dual role: inducing oncolysis of tumor cells and acting as a potent immunological adjuvant that recruits and activates dendritic cells (Ylosmaki et al., 2018, Molecular Therapy). This process promotes the cross-presentation of the attached tumor antigens, leading to a robust systemic T-cell response against the cancer. While the capsid itself is a component of the therapeutic agent rather than a traditional biological target, its interaction with the host immune system and its ability to be neutralized by pre-existing anti-Ad5 antibodies are critical factors in its clinical efficacy and safety (Valo Therapeutics, 2024).

Other names

PeptiCRAdPeptide-coated Conditionally Replicating AdenovirusAd5-D24-CpG capsidVALO-D102 capsid

The viral capsid acts as a scaffold for tumor-specific peptides and an oncolytic agent; it infects tumor cells to induce lysis while simultaneously presenting peptides to the immune system to trigger a T-cell mediated anti-tumor response.