B-lymphocyte antigen CD19, B-lymphocyte antigen CD20, and B-lymphocyte antigen CD22 (CD19/CD20/CD22)

CD19, CD20, and CD22 are three integral membrane glycoproteins predominantly expressed on the surface of B-lymphocytes from the pro-B cell stage through mature B cells, but are typically lost upon differentiation into plasma cells [Creative Diagnostics, 2024; NIH, 2022]. CD19 serves as a critical co-receptor that lowers the threshold for B-cell receptor (BCR) activation, while CD20 is involved in calcium signaling and B-cell differentiation, and CD22 acts as a regulatory co-receptor that modulates BCR signaling [NIH, 2022; NIH, 2021]. These proteins are highly expressed in various B-cell malignancies, including B-cell acute lymphoblastic leukemia (B-ALL) and non-Hodgkin lymphoma (NHL), making them ideal targets for immunotherapy [NIH, 2024; NIH, 2021]. While single-target therapies like CD19-directed CAR-T cells have shown high efficacy, tumor relapse often occurs due to antigen escape or downregulation [NIH, 2024; Science Translational Medicine, 2021]. Consequently, trispecific CAR-T cells and multispecific antibodies targeting CD19, CD20, and CD22 simultaneously are being developed to enhance tumor recognition, overcome resistance mechanisms, and improve the durability of clinical responses [ASH Publications, 2024; Science Translational Medicine, 2021].

Other names

B-lymphocyte surface antigen B4Membrane-spanning 4-domains subfamily A member 1 (MS4A1)Sialic acid-binding Ig-like lectin 2 (Siglec-2)B-lymphocyte antigen CD20B-lymphocyte cell adhesion molecule (BL-CAM)Leu-12B1Leu-16

Drugs targeting this multi-antigen complex primarily utilize chimeric antigen receptor (CAR) mediated T-cell activation to induce direct tumor cell lysis [Science Translational Medicine, 2021]. By simultaneously targeting CD19, CD20, and CD22, these therapies aim to prevent 'antigen escape,' a common resistance mechanism where tumor cells downregulate a single target to evade the immune system [NIH, 2024]. Additionally, component-specific agents may act through antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), or the delivery of cytotoxic payloads via antibody-drug conjugates [NIH, 2021].