Blood group O expression in normal tissues and tumors

Area of Science:

• Immunology
• Biochemistry
• Oncology

Background:

• The H antigen is a precursor to A and B blood groups, found on erythrocytes and other human cells.
• Specific detection of H antigens has been challenging due to a lack of precise reagents.
• Existing detection methods, like Ulex europaeus agglutinin-I (UEA-I), have limitations in specificity.

Purpose of the Study:

• To develop novel, highly specific monoclonal antibodies (mAbs) for detecting H antigens.
• To investigate the expression patterns of H antigens in various human cells and tissues.
• To explore factors influencing H antigen detection, such as sialic acid levels.

Main Methods:

• Generation of monoclonal antibodies (mAbs) by immunizing sea lampreys with human cells.
• Characterization of mAb specificity against H antigens, comparing them to UEA-I.
• Analysis of H antigen expression in mammalian glycoproteins, human cells, and normal/malignant human tissues.
• Evaluation of H antigen detection following enzymatic desialylation or in sialic acid-deficient cells.

Main Results:

• Two specific monoclonal antibodies, Tn4-31L and OmcFL3-02, were successfully generated.
• These mAbs demonstrated high specificity for H antigens, outperforming UEA-I.
• Unexpected H antigen expression was identified in various human carcinomas.
• H antigen detection was significantly enhanced by enzymatic desialylation and in cells lacking sialic acid.

Conclusions:

• The developed mAbs are valuable reagents for accurate H antigen detection in blood testing.
• These antibodies facilitate further exploration of H antigen expression and function in normal and pathological conditions.
• The findings highlight the potential role of H antigens in human carcinomas and the influence of sialic acid on their detection.