Anti-hCD19-CD3

Anti-hCD19-CD3 binds to hCD3 on T cells and to hCD19 on B cells

Monoclonal scFv antibody against human CD19 and human CD3

Anti-hCD19-CD3 is a bispecific antibody that recognizes two human cell markers: hCD19, which is expressed on the surface of (malignant) B cells, and hCD3 which is part of the T cell receptor. This antibody features blinatumomab’s single-chain variable fragments (scFv) joined by a glycine-serine linker and a hexahistidine-tag (His6). Blinatumomab was approved by the FDA as the second line treatment of refractory acute lymphocytic leukemia (ALL) [1].

 More details

Key features:

• Reacts with human CD19 and human CD3
• ScFv of clinical relevant bispecific mAb blinatumomab 
• Hexahistidine (His6) tag
• Provided azide-free
• Each lot is functionally tested

Applications:

• Adjustment studies of B cell contact-dependent killing
• Improving T cell activation

InvivoGen also offers an Anti-hBCMA-CD3 bispecific antibody as well as other clinically relevant antibodies and their corresponding isotype controls. 

References:

1. Krishnamurthy A. & Jimeno A., 2017. Bispecific antibodies for cancer therapy: A review. Pharmacol Ther. S0163-7258(17)30293-0.

Figures

Jurkat-Lucia™ NFAT cell activation upon incubation with Raji B cells and Anti-hCD19-CD3.

A. Evaluation of T cell activation. Raji cells were pre-incubated with Anti-hCD19-CD3, or the two bispecific negative controls Anti-β-Gal-hCD3 and Anti-hCD19-β-Gal for 30 minutes before addition of Jurkat-Lucia™ NFAT cells. After 8 hours incubation, T cell activation was determined by measuring the Lucia luciferase activity using QUANTI-Luc™ detection reagent. Results are presented as relative activity expressed as a percentage of Lucia activity in samples with the highest dose of antibody.
B. Target specificity of Anti-hCD19-CD3 was verified upon incubation with Jurkat-Lucia™ NFAT cells and Raji cells as described in (A), with Jurkat-Lucia™ NFAT cells only, or with Raji cells only. T cell activation was determined by measuring the Lucia luciferase activity using QUANTI-Luc™ and expressed as relative light units (RLUs).

Specifications

Clonality: Monoclonal antibody

Clone: HD37 (Anti-hCD19) and L2K-07 (Anti-hCD3)

Specificity: Targets human CD19 and human CD3

Isotype: none (scFv)

Source: CHO (Chinese hamster ovary) cells

Purity: > 90% Purified by HisTrap affinity chromatography

Tested application: FACS, cellular assays

Quality control:

•    Binding to hCD19 and to hCD3 has been confirmed by flow cytometry.
•    Biological activity has been confirmed using cellular assays.
•    The complete sequence of this antibody has been verified.
•    The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.

Contents

10 µg Anti-hCD19-CD3, purified antibody, provided azide-free and lyophilized.

Product is shipped at room temperature.

Store lyophilized antibody at -20°C.

Lyophilized product is stable for at least 1 year.

Details

CD19

The cluster of differentiation 19 (CD19) is a transmembrane protein acting as a co-receptor for the B cell receptor (BCR) modulating B lymphocyte differentiation and activation [1]. CD19 is expressed throughout the entire B cell maturation process and can be found in most lymphoid malignancies including acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL) and Non-Hodgkin lymphoma (NHL). Therefore, CD19 is an interesting target for the development of experimental therapeutic agents in immunotherapy research [2].

In 2014, the first bispecific T-cell engager (BiTE^®) blinatumomab was approved by the FDA as the second line treatment of refractory ALL. By simultaneously binding to hCD3 and hCD19, blinatumomab (AMG103) engages unstimulated T cells to proliferate and exert cytotoxic activity on CD19-positive lymphoma cells [3].
 

CD3

The cluster of differentiation 3 (CD3, formerly named T3) is a multimeric protein complex consisting of four polypeptides (CD3ε, CD3γ, CD3δ, and CD3ζ) that assemble as three dimers (εγ, εδ, and ζζ) [4]. It is a marker of T cells, which recognizes and participates in the elimination of infected cells and tumor cells through the interaction between the TCR (T cell receptor) on T cells and the MHC-peptide complex on antigen-presenting cells [4-5]. Because of its short cytoplasmic tail, the TCR lacks the ability to signal and requires non-covalent association with the CD3. Upon antigen recognition, the TCR/CD3 complex on T cells triggers downstream intracellular signaling and participates in T cell activation [4].

1. Del Nagro et al., 2005. CD 19 function in central and peripheral B-cell development. Immunol Res 31, 119–131 (2005).
2. Katz, Ben-Zion; Herishanu, Yair, 2014. Therapeutic targeting of CD19 in hematological malignancies: past, present, future and beyond. Leukemia & Lymphoma, 55(5), 999–1006.
3. Zinzani, P.L., Minotti, G., 2022.  Anti-CD19 monoclonal antibodies for the treatment of relapsed or refractory B-cell malignancies: a narrative review with focus on diffuse large B-cell lymphoma. J Cancer Res Clin Oncol 148, 177–190.
4. Chetty R. & Gatter K., 1994. CD3: structure, function, and role of immunostaining in clinical practice. J. Pathol. 173(4):303-307.
5. Smith-Garvin J.E. et al., 2009. T Cell Activation. Ann. Rev. Immunol. 27:591-619.3.