721.221 Human HLA Negative B-Lymphoblastoid Cell Line

The human leukocyte antigen (HLA) gene complex encodes the major histocompatibility complex (MHC) proteins, key regulators of the human immune system. MHC proteins carry antigenic determinants for cell-surface recognition by T cells, and allow for immune autorecognition.1 The diversity of antigens provides a challenge for parsing individual T-cell activators and specific immune responses, and the ability to manipulate specific determinants is a paramount factor for understanding autoimmune diseases that arise from MHC dysfunction.
The 721.221 human HLA-negative B cell lymphoblastoid cell line is a well-established model for immune activation and HLA expression. The absence of class I HLA expression in 721.221 cells allows for functional analysis of individual class I antigens via transformation with individual HLA genes.2 HLA genes are ectopically expressed at quantitatively normal levels in 721.21 cells.2 721.221 cells express the B-cell marker CD19 4 and several NK activator ligands including CD48, CD80, and CD86. 5 The unique characteristics of the 721.221 cell line make it a highly versatile system for immunology research.

Source
The 721.221 cell line was derived from 721 lymphoblastoid cell line exposed to gamma radiation, inducing null mutations in endogenous HLA-A, B, and C class I antigen genes.

References
1. Simpson E. Immunol Suppl. 1988; 1:27-30.
2. Shimizu Y, DeMars R. J Immunol. 1989; 142(9):3320-3328.
3. Lisovsky I, Isitman G, Bruneau J, Bernard NF. J Leukoc Biol 2015; 97(4):761-767.
4. DeBell KE, Simhadri VR, Mariano JL, Borrego F. BMC Immunol 2012; 13:23.
5. Tremblay-McLean A, Coenraads S, Kiani Z, Dupuy FP, Bernard NF. BMC Immunol 2019; 20(1):8

The unique characteristics of the 721.221 cell line make it a highly versatile system for immunology research.

Store in liquid nitrogen. The cells can be cultured for at least 10 passages after initial thawing without significantly affecting the cell marker expression and functionality.

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