InnoScan 710 microarray scanner: new publication

Affinity Maturation and Characterization of the Novel Monoclonal Antibody (mAb) PB-223 Targeting Cancer-Specific O-Glycans Terminating with α(2,6) Sialic Acids

A novel affinity-matured monoclonal antibody, PB-223, has been reported in  Cancers  by researchers from Precision Biologics. This demonstrates significantly improved binding kinetics and tumor-selective recognition of cancer-associated O-glycans. Through FASEBA-based affinity engineering of the parental clinical antibody NEO-102, the team achieved a 4.55-fold reduction in equilibrium dissociation constant (KD) toward Bovine Submaxillary Mucin, a glycoprotein rich in O-glycans. 

To pinpoint the precise glycan epitope, the researchers employed a 94-component O-glycan microarray and performed fluorescence detection using the  InnoScan 710 Microarray Scanner. Quantitative analysis of the scanning data revealed that PB-223 selectively binds to O-glycans terminating with α(2,6) sialic acids, specifically recognizing core 2 O-glycan structures and sTn antigens—glycan signatures frequently dysregulated in carcinogenesis. 

Flow cytometry and immunohistochemistry on tumor microarrays confirmed that PB-223 recognizes a broader range of carcinoma types with higher staining scores compared to NEO-102, including colorectal, pancreatic, lung, and breast cancers. Critically, no immunoreactivity was observed in healthy brain, liver, lung, colon, or lymph node tissues. Faint staining was detected only in goblet cells adjacent to colorectal tumors and in endocervical glandular cells from one-third of peritumoral cervical normal tissues, suggesting minimal off-target risk. Live-cell internalization assays further demonstrated efficient uptake of PB-223 into antigen-positive OV-90 ovarian cancer cells, providing a strong rationale for antibody-drug conjugate development. 

Notably, the quantitative glycan microarray data acquired via the  InnoScan 710  were instrumental in defining the exact glycan epitope recognized by PB-223, thereby establishing the molecular foundation for its exceptional tumor-selective binding specificity and supporting its translational potential as a targeted therapeutic agent.

Original article: Affinity Maturation and Characterization of the Novel Monoclonal Antibody (mAb) PB-223 Targeting Cancer-Specific O-Glycans Terminating with α(2,6) Sialic Acids

Keywords

• O-glycan microarray
• Affinity maturation
• Tumor-selective antibody
• Antibody-drug conjugate (ADC) 
• Innoscan 710
• MAPIX