Human 4-1BB-expressing Raji Cells

Human 4-1BB-expressing B cells

Raji-h4-1BB cells were developed from the human Raji cell line, a human B lymphocyte-derived cell line, and engineered to stably overexpress the human 4‑1BB gene. Raji cells have been successfully used as target cells in antibody effector studies such as antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) assays with peripheral T cell-derived Jurkat reporter cells.

4-1BB (also known as CD137 or TNFSF9) is a co-stimulatory immune checkpoint (IC) receptor that belongs to the tumor necrosis factor receptor (TNFR)/TNF superfamily. 4-1BB is expressed on a multitude of cells including activated CD8+ and CD4+ T cells [1]. Upon 4-1BB binding to its ligand, 4-1BBL (CD137L), expressed on antigen-presenting cells (APCs), NF‑κB‑dependent signaling is activated within the T cell, powerfully augmenting T cell activation, proliferation, and survival [1]. Notably, activation of 4-1BB has the capacity to mediate strong effector T cell immune responses and thus, makes it an attractive target for cancer immunotherapy [1,2]. Despite 4-1BB agonistic antibodies eliciting potent anti-tumor responses, monotherapy progress has been limited in the clinic  [2]. However, combinational therapies may be promising with a significant synergistic effect observed when used in combination with IC inhibitory antibodies (e.g. Anti-CTLA-4 and Anti-PD-1) [1,2].

Features of Raji-h4-1BB cells:

• Stable overexpression of the human 4-1BB gene
• Characterized by a number of cell-surface expressed markers including the B cell receptor (BCR), CD19, and CD20
• Constitutive expression of various immune checkpoints (ICs) such as CD27, CD70, CD80, PD-L1, and 4-1BBL

Applications for Raji-h4-1BB cells:

• Target cell line for ADCC and ADCP assays using InvivoGen's Jurkat-Lucia™ NFAT-CD16 cells and Jurkat-Lucia™ NFAT-CD32 cells, respectively.
• Target cell line for cell toxicity assays using NK or CAR-T cells
• For use in the development novel human 4-1BB mAbs

Validation of Raji-h4-1BB cells:

• Overexpression of 4-1BB verified by flow cytometry
• Functionally tested as target cells in ADCC assays using anti-human 4-1BB mAbs and Jurkat-Lucia™ NFAT-CD16 cells
• Guaranteed mycoplasma-free

​References:

1. Bartkowiak, T. & Curran, M.A. 2015. 4-1BB Agonists: Multi-Potent Potentiators of Tumor Immunity. Front Oncol 5, 117.
2. Ascierto, P.A. et al. 2010. Clinical experiences with anti-CD137 and anti-PD1 therapeutic antibodies. Semin Oncol 37, 508-516.