The CD160 molecule (BY55 antigen) is a 27-kDa, glycosyl phosphatidylinositol (GPI)-anchored glycoprotein of 181 amino acids, with a single immunoglobulin (Ig)-like domain. The molecule contains two potential sites for N-glycosylation and is rich in cysteine (6 residues in the mature polypeptide), indicating an important capacity for forming intra- and inter-chain disulfide bonds, which likely support the disulfide-linked multimeric (80 kDa) expression at the cell surface. Its expression is highly restricted to circulating cytotoxic T and NK cells, and in tissues, to intestinal intraepithelial lymphocytes, as revealed by CD160 mRNA blot analysis and various phenotyping studies. In peripheral blood, CD160+ cells consist of a majority of CD3– TCRγδ+ NK cells, which is significantly reduced in HIV+ individuals, and of a minority of CD3+ CD8bright T lymphocytes, which is significantly increased in HIV+ individuals. In bone marrow, CD160+ cells, though less abundant than in adult peripheral blood, also consist of the two populations observed in peripheral blood. In cord blood, CD160+ cells consist of a unique CD3– TCR– NK cell population, 80% of these cells being CD56+. CD160 is a ligand for classical and non-classical MHC-class I molecules. The ligation of MHC-class I by CD160 provides a costimulatory signal restricted to peripheral blood activated T cells, suggesting a pathway being additional and/or alternative to the CD28 costimulation mechanism. This pathway may be relevant in memory T cells that lack CD28, such as the intestinal intraepithelial lymphocytes.


Specificity CD160
Form PE
Clone BY55
Flow Product Line IOTest
Clone Description The BY55 antibody was initially reported to react with a protein structure of 80 kDa exclusively expressed by circulating cytotoxic lymphocytes. It does not block the binding of the CD160 molecule to MHC-class I molecules.
Isotype IgM Mouse
Format Liquid
Size 2.00|mL
Target Species Human
Cross Reactivity BY55 cross reacts with: Sooty Mangabey
Other Names BY55, CD160, NK1, NK28
Regulatory Status ASR


The listed regulatory status for products correspond to one of the below:
IVD: In Vitro Diagnostic Products. These products are labeled "For In Vitro Diagnostic Use."
ASR: Analyte Specific Reagents. These reagents are labeled "Analyte Specific Reagents. Analytical and performance characteristics are not established."
CE: Products intended for in vitro diagnostic use and conforming to European Directive (98/79/EC). (Note: Devices may be CE marked to other directives than (98/79/EC)
RUO: Research Use Only. These products are labeled "For Research Use Only. Not for use in diagnostic procedures."
LUO: Laboratory Use Only. These products are labeled "For Laboratory Use Only."
No Regulatory Status: Non-Medical Device or non-regulated articles. Not for use in diagnostic or therapeutic procedures.