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

B-lymphocyte antigen CD19 and B-lymphocyte antigen CD20 are cell surface proteins predominantly expressed on B-lymphocytes throughout most stages of their differentiation, from pro-B cells to mature B cells (UniProt P15391; UniProt P11836). CD19 functions as a critical co-receptor for B-cell receptor (BCR) signaling, while CD20 is a tetra-spanning transmembrane protein involved in B-cell activation and calcium flux (PubMed: 15661040). These molecules are highly expressed in various B-cell malignancies, including non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL), making them primary targets for immunotherapy (StatPearls: B-cell Lymphoma). Dual targeting of CD19 and CD20 has emerged as a therapeutic strategy to overcome "antigen escape," where tumor cells downregulate a single target antigen to evade immune detection (Nature Medicine: Shah et al., 2020). By utilizing bispecific antibodies or tandem CAR-T cells that recognize both antigens, such as Zamocabtagene autoleucel, clinicians aim to provide more comprehensive B-cell depletion and reduce the likelihood of relapse (NIH: ClinicalTrials.gov).

Other names

CD19/CD20 dual targetCD19+ CD20+ B-cell antigensB-cell surface antigen B4 and B1MS4A1 and CD19

Simultaneous or sequential binding to CD19 and CD20 antigens on B-cells, leading to cell death via antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), or direct T-cell mediated cytotoxicity.