Human VISTA-expressing Raji Cells

Human VISTA-expressing B cells

Raji-hVISTA cells were developed from the human Raji cell line, a human B lymphocyte-derived cell line. Raji cells have been successfully used as target cells in human effector studies such as antibody-dependent cellular cytotoxicity (ADCC), either with peripheral blood mononuclear cells, natural killer (NK) cells, or T cell-derived Jurkat reporter cells.

V-domain Ig containing suppressor of T cell activation (VISTA), also known as programmed death-1 homolog (PD-1H), is a member of the CD28/B7 protein superfamily [1].  Similar to other immune checkpoints (ICs), VISTA is found to be heightened on immune cells that infiltrate the tumor microenvironment (TME). It is predominantly expressed on antigen-presenting cells (APCs) and directly suppresses T cell activation and proliferation [1,2]. Additionally, VISTA is expressed on a number of T cells subsets and can thus be considered both as a ligand and a receptor, whereby it transmits both extrinsic and intrinsic inhibitory signals to T cells [2]. PSGL-1 has been identified as a receptor for VISTA and interestingly, its engagement suppresses T cells selectively in an acidic pH, such as that found in the TME [3]. It has been suggested that VISTA and PD-1 suppress T cell function in a synergistic manner, and therefore, combined therapy targeting both ICs has been considered extremely promising [4].

Features of Raji-hVISTA cells:

• Stable overexpression of the human VISTA 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-hVISTA cells:

• Target cell line for ADCC assays using InvivoGen's Jurkat-Lucia™ NFAT-CD16 cells
• Target cell line for cell toxicity assays using NK or CAR-T cells
• For use in the development of other functional assays

Validation of Raji-hVISTA cells:

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

​References:

1. Nowak, E.C. et al. 2017. Immunoregulatory functions of VISTA. Immunol Rev 276, 66-79.
2. Xu, W. et al. 2018. The structure, expression, and multifaceted role of immune-checkpoint protein VISTA as a critical regulator of anti-tumor immunity, autoimmunity, and inflammation. Cell Mol Immunol 15, 438-446.
3. Johnston, R.J. et al. 2019. VISTA is an acidic pH-selective ligand for PSGL-1. Nature 574, 565-570.
4. Liu, J. et al. 2015. Immune-checkpoint proteins VISTA and PD-1 nonredundantly regulate murine T-cell responses. PNAS112:6682–7.