Products from Ancell

Human T cell receptor (TCR) is a T cell surface expressed heterodimer of alpha/beta or gamma/delta chains. TCR's recognize antigen peptides bound to MHC molecules forming the basis of antigen specific response by T cells.

Human CD8 is a heterodimeric protein consisting of an alpha and beta chain, each about 33kDa. CD8 is expressed on most thymocytes and on about one third of peripheral blood T cells. CD8 is a co-receptor involved in antigen recognition and binds to the alpha2 and alpha3 domain of MHC Class I molecules.

Expression of human CD25 (the alpha subunit of the IL-2 receptor complex) is dramatically upregulated on activated T cells, B cells, NK cells and macrophages. Antibodies to CD25 are being studied for potential use as an immunodirected therapy to selectively attack (kill) CD25 expressing cells.

Human CD64 is a high affinity receptor for monomeric human IgG1 and IgG3 which is expressed on macrophages, monocytes and gamma-interferon induced neutrophils. CD64 plays an important role in clearance of immune complexes and in antibody dependent cytoxicity.

Human CD74 is expressed intracellularly and on the cell surface of MHC Class II positive cells such as B cells, monocytes, macrophages, Langerhans cells and dendritic cells. CD74 has several important functions relating to antigen presentation by MHC Class II molecules.

The inducible costimulator CD278 (ICOS) is similar to human CD28 (24% homology) and plays an analogous role in the T cell activation process. Secondary signaling through CD28 or CD278 results in discrete cytokine secretion profiles by the activated T cells. CD275 (ICOSL, GL50, B7-H2) has been shown to be the ligand for CD278 (ICOS).

Human CD81 is a member of the tetraspan family of leukocyte cell surface molecules which are involved in signal transduction, cell-cell adhesion and cellular activation. Association of CD81 with integrins appears to be functionally important in the regulation of cell adhesion and activation. Recent work with CD81-null mice indicates CD81 is important for development of...

Human CD105 (endoglin) is a homodimeric membrane glycoprotein virtually restricted to endothelial cells and present on some leukemia cells and minor subsets of bone marrow cells. CD105 binds to TGF-beta1 and beta3 with high affinity.

Human CD106 is an endothelial adhesion molecule that binds to alpha 4 beta 1 and alpha 4 beta 7 integrins (VLA-4) and promotes adhesion of lymphocytes, monocytes, eosinophils and basophils. CD106 is also found on follicular dendritic cells, interdigitating recticulum cells and Kupffer cells.

Human perforin (cytolysin) is believed to be one of the major effector molecules used by cytotoxic T cells and NK cells to mediate targeted cell lysis. Perforin expression is constitutive on NK cells, but increases in resting CD8 cytotoxic cells upon activation.

Human CD40 is a member of the TNF receptor family and is present on all B cells except plasma cells. CD40 is also found on some epithelial cells, carcinomas and lymphoid dendritic cells. CD40 plays an important role in B cell activation and the interaction with its ligand CD154 (CD40 ligand) is essential for isotype switching.

Human CD28 is an important costimulatory molecule found on all CD4 T cells and on about half of the CD8 T cells. T cell activities attributed to CD28 include prevention of anergy, induction of cytokine gene transcription, stabilization of cytokine mRNA and activation of CD8 cytotoxic T lymphocytes. The ligands for CD28 identified as CD80 (B7-1) and CD86 (B7-2) are...