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

B-lymphocyte antigen CD19 and B-lymphocyte antigen CD22 are two critical surface receptors expressed throughout the development of B-lineage cells and on the majority of B-cell malignancies [7, 16]. CD19 functions as a dominant co-receptor that lowers the threshold for B-cell receptor (BCR) signaling, while CD22 is a member of the Siglec family that typically acts as an inhibitory regulator of B-cell activation [7, 11]. The simultaneous targeting of both CD19 and CD22 has emerged as a prominent therapeutic strategy, particularly in the development of bispecific chimeric antigen receptor (CAR) T-cell therapies [1, 3, 5]. This dual-targeting approach is specifically designed to overcome the challenge of antigen escape, where tumor cells evade single-target therapies by downregulating or losing the expression of one antigen, such as CD19 [4, 6, 9]. By requiring the loss of two independent antigens for escape, bispecific therapies aim to achieve more durable clinical remissions in patients with relapsed or refractory B-cell acute lymphoblastic leukemia and non-Hodgkin lymphoma [2, 8, 10]. Clinical studies have shown that these dual-targeted agents maintain high efficacy while exhibiting a safety profile characterized by manageable toxicities like cytokine release syndrome [12, 14, 15].

Other names

B-lymphocyte antigen CD19B-lymphocyte antigen CD22CD19CD22B-cell surface antigen B4Siglec-2BL-CAMSialic acid-binding Ig-like lectin 2Leu-12

Dual-antigen targeting, T-cell mediated cytotoxicity, Prevention of antigen escape, B-cell receptor signaling modulation