Tumor-associated antigens presented via gp96-Ig (TAA/gp96-Ig)

Tumor-associated antigens (TAAs) presented via the gp96-Ig platform represent a novel immunotherapeutic approach designed to trigger a broad, polyvalent anti-tumor immune response. gp96 (also known as Grp94 or HSP90B1) is an endoplasmic reticulum-resident chaperone that naturally binds to a wide repertoire of intracellular peptides, including those specific to the tumor from which it is derived (UniProt P14625). In this system, gp96 is engineered as a fusion protein with the Fc portion of IgG1 (gp96-Ig), allowing it to be secreted by vaccine cells and effectively carry TAAs to professional antigen-presenting cells (APCs) (Strbo et al., 2013). Upon secretion, the gp96-Ig-peptide complex binds to the CD91 receptor on dendritic cells, facilitating the cross-presentation of antigens on both MHC class I and II molecules (Binder et al., 2000). This process leads to the robust activation and expansion of tumor-specific CD8+ cytotoxic T-lymphocytes (CTLs), which can then target and eliminate cancer cells throughout the body (Fromm et al., 2016). This technology is currently being evaluated in clinical trials, most notably as Viagenpumatucel-L (HS-110), for the treatment of non-small cell lung cancer and other solid tumors (NCT02143466). The platform's ability to present a diverse array of antigens makes it particularly useful for addressing tumor heterogeneity and preventing immune escape. Safety profiles in clinical studies have generally shown the approach to be well-tolerated, with most adverse events being low-grade injection site reactions or systemic immune activation symptoms.

Other names

gp96-Ig vaccine platformHSP90B1-Ig fusion proteinGrp94-IgViagenpumatucel-L antigensTumor-derived chaperone-peptide complexes

The gp96-Ig fusion protein acts as a molecular chaperone that carries tumor-associated antigens to dendritic cells; it binds to the CD91 receptor, triggering antigen cross-presentation and the subsequent activation of a polyvalent CD8+ T-cell response.