CD19 Products

Description

CD19 (Cluster of Differentiation 19), also known as B-lymphocyte surface antigen B4, is a type 1 transmembrane glycoprotein belonging to immunoglobulin (Ig) subfamily that serves as a biomarker for normal and neoplastic B cells (1,2). CD19 is a co-receptor for the B cell receptor (BCR) signaling complex and has a critical role in regulating B cell signaling and immune response (1,2). The CD19 protein contains an extracellular N-terminus containing two C2 Ig-like domains separated by a helical non-Ig domain, a single pass transmembrane domain, and a highly conserved cytoplasmic C-terminal domain (1,2). The human CD19 protein, encoded by the CD19 gene located on chromosome 16p11.2, is 556 amino acids (aa) in length with a calculated theoretical molecular weight (MW) of 61 kDa and an observed molecular weight of 95 kDa (1-3). CD19 associates with other molecules - CD21, CD81, and CD225 - to form the BCR co-complex, also called the CD19 complex, through CD21 binding to the complement C3d complex (1-3). Complement C3d bridges the BCR with the CD19 complex into lipid rafts of the plasma membrane (1-3). CD19 is capable of modulating B cell development through both BCR-dependent and -independent signaling (1-3). Upon BCR activation, the tyrosine residues of CD19's cytoplasmic tail recruits multiple kinases including Lyn, Vav, and PI3K, amplifying BCR-mediated immune signaling and B cell activation (1-3).

Considering the role of CD19 in BCR signaling and its expression in development from pre-B cells through plasma cells, it is understandable that CD19 dysfunction and abnormal expression is associated with numerous B cell malignancies and autoimmune disorders (1-5). CD19 expression is typically observed at relatively normal levels in B cell acute lymphoblastic leukemia (B-ALL) and chronic lymphoblastic leukemia (CLL) but is often reduced other types of lymphoma including diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL) (1,2). On the other hand, CD19 expression is typically increased in autoimmune disorders such as systemic sclerosis (SSc) and multiple sclerosis (MS) as modeled by experimental autoimmune encephalomyelitis (EAE) (2). CD19 has become a therapeutic molecular target for the treatment of B cell lymphomas and autoimmune disorders using monoclonal antibodies (mAbs), bi-specific T cell engaging (BiTE) antibodies, and CD19-specific chimeric antigen receptor (CAR) T cells (1,2,4-6). Although anti-CD19 CAR T cell therapy has become the standard for the treatment of B cell malignancies, patients may experience relapse due to resistance mechanisms (6). Strategies to improve efficacy and limit relapse include combination of CAR T cell therapy with immune checkpoint inhibitors like anti-PD-1 (4,6).

References

1. Wang K, Wei G, Liu D. CD19: a biomarker for B cell development, lymphoma diagnosis and therapy. Exp Hematol Oncol. 2012;1(1):36. https://doi.org/10.1186/2162-3619-1-36

2. Li X, Ding Y, Zi M, et al. CD19, from bench to bedside. Immunol Lett. 2017;183:86-95. https://doi.org/10.1016/j.imlet.2017.01.010

3. Wentink MWJ, van Zelm MC, van Dongen JJM, Warnatz K, van der Burg M. Deficiencies in the CD19 complex. Clin Immunol. 2018;195:82-87. https://doi.org/10.1016/j.clim.2018.07.017

4. Frigault MJ, Maus MV. State of the art in CAR T cell therapy for CD19+ B cell malignancies. J Clin Invest. 2020;130(4):1586-1594. https://doi.org/10.1172/JCI129208

5. Penack O, Koenecke C. Complications after CD19+ CAR T-Cell Therapy. Cancers (Basel). 2020;12(11):3445. https://doi.org/10.3390/cancers12113445

6. Bouziana S, Bouzianas D. Anti-CD19 CAR-T cells: Digging in the dark side of the golden therapy. Crit Rev Oncol Hematol. 2021;157:103096. https://doi.org/10.1016/j.critrevonc.2020.103096

Bioinformatics

Entrez	12478 Mouse 930 Human
Uniprot	NM_001770 Human NP_001761 Human NP_001761.3 Human P15391 Human
Product By Gene ID	930
Alternate Names	B4 B-lymphocyte antigen CD19 B-lymphocyte surface antigen B4 CD19 antigen CD19 molecule CVID3 Differentiation antigen CD19 MGC12802 T-cell surface antigen Leu-12

Research Areas for CD19

Find related products by research area and learn more about each of the different research areas below.

Adaptive Immunity
CD Markers
Cytokine Research
Immunology
Mesenchymal Stem Cell Markers
Signal Transduction
Stem Cell Lines
Stem Cell Markers

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CD19: An Undoubted Biomarker for B Cells CD19 is a cell surface protein member of the large immunoglobulin superfamily that complexes with CD21, CD81, and CD225 in the membrane of mature B-cells. A major function of CD19 is to assemble with the antigen receptor of B-lymphocytes to decrease t...    Read more.

Harnessing Natural Killer Cell Activity for Anti-Tumor Immunotherapy By Victoria Osinski, PhDWhat’s “Natural” About Natural Killer (NK) Cells?For immunologists, the term cytotoxicity often conjures up images of an army of antigen specific CD8+ T cells deploying to ...    Read more.

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