B-lymphocyte antigen CD19 (Mus musculus) (CD19)

Murine CD19 (B-lymphocyte antigen CD19) is a 95 kDa type I transmembrane glycoprotein belonging to the immunoglobulin superfamily, expressed specifically on B-lineage cells from the pro-B cell stage through mature B cells, but lost upon differentiation into plasma cells [1, 2]. It acts as a crucial co-receptor for the B-cell receptor (BCR), forming a complex with CD21 and CD81 to lower the threshold for antigen-induced signaling and B-cell activation [1, 3]. In preclinical research, murine CD19 is a primary target for evaluating the safety and efficacy of B-cell-directed therapies, such as Chimeric Antigen Receptor (CAR) T-cells and bispecific T-cell engagers (BiTEs), in syngeneic mouse models [4, 5]. These models allow researchers to study the dynamics of B-cell depletion, cytokine release syndrome (CRS), and long-term immune reconstitution in an immunocompetent setting [5]. While human CD19 is the clinical target for drugs like blinatumomab and tisagenlecleucel, the murine version is indispensable for surrogate testing using antibodies like the 1D3 clone [3, 4]. Targeting murine CD19 typically results in profound B-cell aplasia, which serves as a biomarker for therapeutic activity [5]. Sources: [1] UniProt (P25918); [2] NCBI Gene (12478); [3] Krop et al. (1996) Eur J Immunol; [4] Davila et al. (2013) PLoS ONE; [5] Cheadle et al. (2014) Immunology.

Other names

B-lymphocyte surface antigen B4CD19 moleculeB4CVID3Differentiation antigen CD19

B-cell depletion via antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), or redirected T-cell mediated lysis.