Tumor-Associated SLe^a Antigen Production Service at CD BioGlyco

• The role of SLe^a in cancer study

SLe^a is referred to as the CA19-9 antigen, which is identified by murine monoclonal antibody 19-9 (mAb19-9). This antigen is present on the cancer cell surface as a glycolipid and an O-linked glycoprotein. It exhibits elevated expression levels in gastrointestinal epithelial malignancies like colon and pancreatic cancer, as well as in breast and small cell lung cancer. Notably, sLe^a expression is restricted to normal tissues. It serves as a ligand for endothelial cell selectins, implying its involvement in cancer metastasis and adhesion. Due to these characteristics, SLe^a presents itself as a promising target for antibody-based immunotherapies, encompassing monoclonal antibodies and tumor vaccines.

Fig.1 Cell-surface fucosylated antigens. Type I (H1, Le^a, Le^b, and sLe^a) and type II (H2, Le^x, Le^y, and sLe^x). (Blanas, et al., 2018)

• SLe^a production and conjugation service at CD BioGlyco

At CD BioGlyco, based on our mature and professional Glyco™ Vaccine Development Service Platform we provide our clients with custom and advanced Tumor-Associated Carbohydrate Vaccine Development services that help clients study the field of glycobiology. Besides the sLe^a antigen production service, we also provide other Tumor-Associated Lacto-series Antigen Production services such as Le^a Antigen Production Service and Le^b Antigen Production Service. For sLe^a antigen production, we provide the total synthesis and sLe^a-KLH conjugate construction services.

The total synthesis of sLe^a

The total synthesis of sLe^a, a highly complex carbohydrate antigen, presents a formidable challenge due to its intricate structural composition. CD BioGlyco has successfully developed a standardized synthesis pathway for sLe^a, leveraging cutting-edge glycosylation technology and commencing from appropriately protected monosaccharide, disaccharide, and trisaccharide intermediates. At each stage of the synthesis process, rigorous characterization is performed, combining NMR spectroscopy with mass spectrometry analysis. Notably, the ¹H-NMR spectrum of the final sLe^a pentenyl glycoside, being conducted in deuterated water, exhibits a precise alignment with the anticipated sLe^a structure, confirming the accuracy of our synthesis methodology.

Fig.2 General process of the total synthesis of sLe^a. (CD BioGlyco)

SLe^a-KLH conjugate construction

The most successful approach for stimulating antibodies against specific autoantigens, like sLe^a, involves binding the antigen to an immunogenic protein carrier, such as keyhole limpet hemocyanin (KLH). KLH, a highly immunogenic protein sourced from keyhole limpet blood, serves as the platform for pentenyl group conjugation, following a method similar to that depicted in Fig.3. To form the sLe^a-KLH conjugate, we initiate the process with ozonolytic cleavage of the pentenyl double bond. Subsequently, the resulting aldehyde reacts with the hydrazine group of MMCCH in the presence of sodium cyanoborohydride, resulting in the sLe^a-MMCCH compound. Simultaneously, KLH undergoes treatment with 2-iminothiolane, introducing thiol groups through the lysine ε-amino groups and resulting in thiolated KLH. Finally, in a buffered solution, the sLe^a-MMCCH and the thiolated KLH are combined to produce the sLe^a-KLH conjugate.

• The concentration of sLe^a, as well as the sLe^a/KLH epitope ratio within the conjugate, is determined using resorcinol.
• The sialic acid content of both sLe^a and KLH is measured using a dye-binding method.
• The sLe^a-HSA conjugate, intended for ELISA applications, is prepared using a reductive amination method similar to the approach used for the STn-KLH conjugate.

The sLe^a-KLH conjugate is an essential component in vaccine development, particularly for gastrointestinal cancers. In cancer immunotherapy, sLe^a is a critical tumor-associated carbohydrate antigen. The sLe^a-KLH conjugate serves as a vaccine to elicit an immune response against sLe^a-expressing cancer cells, which can be a valuable strategy for cancer treatment. It is a potential immunotherapeutic approach to target gastrointestinal cancers such as pancreatic cancer and other malignancies characterized by sLe^a overexpression.

Fig.3 Preparation of sLe^a-KLH conjugate involves ozone cleavage of sLe^a pentenyl glycoside and use of the heterobifunctional cross-linker 4-(4-N-maleimidomethyl) cyclohexane-1-carboxyl hydrazide (MMCCH). (Ragupathi, et al., 2009)

Applications of Tumor-Associated SLe^a Antigen Production Service

• SLe^a antigen serves as a valuable biomarker for the diagnosis of different cancer types, including pancreatic, colorectal, and lung cancer.
• SLe^a antigen can be employed as a biomarker to detect cancer at its early stages.
• SLe^a antigen can be used as a target for immunotherapy strategies, including the development of monoclonal antibodies and cancer vaccines.
• Researchers can utilize sLe^a antigen in drug development studies to test the effectiveness of new cancer treatments and therapies.

Advantages of Us

• We have a well-equipment vaccine development platform for clients to provide custom-scale sLe^a antigen.
• We employ outstanding lab operators to handle these conjugation and analysis experiments.
• We have an analytical platform that provides a wide range of high-quality, excellent, and suitable custom analysis services for glycochemical analysis.

CD BioGlyco is a leading company in the field of glycobiology research and we provide high-quality and outstanding sLe^a antigen production service. If you would like to know more about our service, please do not hesitate to contact us for more details.

References

1. Blanas, A.; et al. Fucosylated antigens in cancer: an alliance toward tumor progression, metastasis, and resistance to chemotherapy. Frontiers in oncology. 2018, 8: 39.
2. Ragupathi, G.; et al. Synthesis of sialyl Lewis a (sLe^a, CA19-9) and construction of an immunogenic sLe^a vaccine. Cancer immunology, immunotherapy. 2009, 58: 1397-1405.