CD22 Antibodies

Structure of CD22

CD22 is a type I transmembrane glycoprotein with a molecular weight of approximately 95-140 kDa. The difference in molecular weight mainly results from the varying degrees of glycosylation modification.

This protein is composed of 807 amino acids, and its extracellular segment contains 7 immunoglobulin-like domains (among which the N-terminal V-type domain is responsible for binding to α2, 6-sialic acid). The third immunoglobulin domain of CD32 mediates protein dimerization, while the intracellular segment contains three classical immune receptor tyrosine inhibitory motifs (ITIMs), which can recruit SHP-1 phosphatase after phosphorylation. Its ligand binding characteristics depend on sialidase activity, and this unique recognition mechanism enables it to play a key regulatory role in B-cell signal transduction.

Fig. 1 Three-dimensional structure of human CD22.¹

Key structural properties of CD22:

• The extracellular segment contains seven immunoglobulin-like domains (Ig1-Ig7)
• The V-type Ig domain specifically recognizes the α2, 6-linked sialic acid glycosylated ligand
• The transmembrane region forms a co-receptor structure with the BCR complex
• Intracellular section contains three conservative motif to suppress the immune receptor tyrosine kinases (ITIM)
• The 5th and 6Ig domains mediate cis-interactions with CD45RO

Functions of CD22

The main function of CD22 is to act as a negative regulatory factor for B-cell immune responses. However, it is also involved in a variety of immune regulatory processes, including intercellular interactions and signal transduction regulation.

The binding characteristics of CD22 to ligands are characterized by calcium ion-dependent low-affinity interactions (Kd≈200μM). This rapid dissociation kinetics enables it to dynamically scan the glycoylation patterns on the cell surface, thereby regulating the functional status of B cells in real time.

Applications of CD22 and CD22 Antibody in Literature

1. Okuzono, Yuumi, et al. "B-cell immune dysregulation with low soluble CD22 levels in refractory seronegative myasthenia gravis." Frontiers in Immunology 15 (2024): 1382320. https://doi.org/10.3389/fimmu.2024.1382320

This study, through single-cell sequencing and plasma proteomics analysis, found that patients with refractory seronegative myasthenia gravis (MG) had abnormal proliferation of B cells and a reduction in regulatory T cells. The level of soluble CD22 derived from the mature line of B cells in their plasma was significantly decreased and was related to the severity of the disease, suggesting that targeting B cells and CD22 may become a new treatment strategy.

2. Dai, Hanren, et al. "Bispecific CAR-T cells targeting both CD19 and CD22 for therapy of adults with relapsed or refractory B cell acute lymphoblastic leukemia." Journal of hematology & oncology 13.1 (2020): 30. https://doi.org/10.1186/s13045-020-00856-8

This study conducted a Phase I trial of CD19/CD22 bispecific CAR-T treatment for relapsed/refractory B-ALL. The results showed that this therapy could effectively eliminate cancer cells. All six patients achieved MRD-negative complete remission, and no neurotoxicity occurred. However, one patient relapsed accompanied by CD19 deletion and down-regulation of CD22 expression, suggesting that the issue of antigen escape needs further attention.

3. Cordoba, Shaun, et al. "CAR T cells with dual targeting of CD19 and CD22 in pediatric and young adult patients with relapsed or refractory B cell acute lymphoblastic leukemia: a phase 1 trial." Nature medicine 27.10 (2021): 1797-1805. https://doi.org/10.1038/s41591-021-01497-1

This study conducts a Phase I clinical trial of bispecific CAR-T (AUTO3) targeting CD19 and CD22 in children and young patients with relapsed/refractory B-ALL. The results showed that the treatment was safe, with no serious toxic or side effects, and the complete remission rate reached 86% at one month. However, the long-term insufficient persistence of CAR-T cells leads to recurrence, suggesting that the maintenance strategy needs to be improved to exert the therapeutic potential of dual-target therapy.

4. Fergusson, Nathan J., et al. "A systematic review and meta-analysis of CD22 CAR T-cells alone or in combination with CD19 CAR T-cells." Frontiers in Immunology 14 (2023): 1178403. https://doi.org/10.3389/fimmu.2023.1178403

This review analysis shows that CD22 and CD19/CD22 dual-target CAR-T therapies have high response rates in both acute lymphoblastic leukemia (ALL) and lymphoma (NHL), reaching 68% and 90% (ALL) and 64% and 47% (NHL), respectively. Moreover, the incidence of severe toxic and side effects is low, and the safety is good.

5. Spiegel, Jay Y., et al. "CAR T cells with dual targeting of CD19 and CD22 in adult patients with recurrent or refractory B cell malignancies: a phase 1 trial." Nature medicine 27.8 (2021): 1419-1431. https://doi.org/10.1038/s41591-021-01436-0

The article indicates that in response to the issue of easy recurrence after CD19-targeted CAR-T treatment, a Phase I clinical trial for relapsed/refractory B-cell malignant tumors shows that the bispecific CD19-22 CAR-T therapy has good safety and can partially overcome the drug resistance caused by CD19-negative/low expression. However, the targeting efficiency of CD22 and the secretion levels of cytokines still need to be optimized.

Creative Biolabs: CD22 Antibodies for Research

Creative Biolabs specializes in the production of high-quality CD22 antibodies for research and industrial applications. Our portfolio includes monoclonal antibodies tailored for ELISA, Flow Cytometry, Western blot, immunohistochemistry, and other diagnostic methodologies.

• Custom CD22 Antibody Development: Tailor-made solutions to meet specific research requirements.
• Bulk Production: Large-scale antibody manufacturing for industry partners.
• Technical Support: Expert consultation for protocol optimization and troubleshooting.
• Aliquoting Services: Conveniently sized aliquots for long-term storage and consistent experimental outcomes.

For more details on our CD22 antibodies, custom preparations, or technical support, contact us at email.