Development and characterization of a novel B7-H3 rabbit monoclonal antibody for glioma diagnosis.

BACKGROUND: Glioma is the most common primary brain tumor of the central nervous system and is associated with poor clinical outcomes, particularly in high-grade diease. The immune checkpoint protein B7-H3 (CD276) is significantly overexpressed in glioma and multiple other solid tumors, highlighting its potential as a diagnostic biomarker and therapeutic target. However, the availability of high-performance antibodies suitable for clinic in vitro diagnosis (IVD) applications remains limited. OBJECTIVE: This study aimed to develop a novel rabbit monoclonal antibody (clone 36H7) targeting human B7-H3, and to evaluate its suitability for clinical diagnostic use. METHODS: Rabbits were immunized with recombinant human B7-H3 protein, followed by monoclonal antibody generation and systematic screening. The resulting antibody was assessed for specificity, affinity and stability. Its performance was validated through Western blot, ELISA, surface plasmon resonance (SPR), flow cytometry, immunofluorescence, and immunohistochemistry (IHC). RESULTS: Clone 36H7 demonstrated high specificity and robust stability across multiple assay platforms. In IHC analysis of glioma samples (n = 206), B7-H3 positivity was detected in 97% of cases. In addition, B7-H3 expression was observed in 85.4% of vascular endothelial cells, supporting its strong detection capability in tumor-associated compartments. Tonsil tissue was established as a reliable quality control material to ensure assay consistency and reproducibility. CONCLUSION: The rabbit monoclonal antibody 36H7 exhibits excellent specificity, stability and board applicability across analytical platforams, meeting key requirments for clinical diagnostic development targeting B7-H3 in glioma.