Invitrogen™ CD28 Monoclonal Antibody (5B8), APC, eBioscience™

Description

Description: The 5B8 monoclonal antibody reacts with canine CD28, which is expressed by thymocytes, a majority of T cells, and a subset of NK cells. CD28 is a ligand for CD80 (B7-1) and CD86 (B7-2) and is a potent costimulator of T cells. Signaling through CD28 augments IL-2 and IL-2 receptor expression as well as cytotoxicity of CD3-activated T cells. The 5B8 antibody has been reported to have agonist activity. The 5B8 and 1C6 antibodies recognize different epitopes of canine CD28. Applications Reported: This 5B8 antibody has been reported for use in flow cytometric analysis. Applications Tested: This 5B8 antibody has been pre-titrated and tested by flow cytometric analysis of normal canine peripheral blood cells. This can be used at 5 μL (0.25 μg) per test. A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 μL. Cell number should be determined empirically but can range from 10^5 to 10^8 cells/test. Excitation: 633-647 nm; Emission: 660 nm; Laser: Red Laser. Filtration: 0.2 μm post-manufacturing filtered.

CD28 antigen is a 44 kDa disulfide linked homodimeric T cell specific surface glycoprotein. CD28 is a cell adhesion molecule of the immunoglobulin superfamily which is constitutively expressed on most peripheral blood T lymphocytes. Moreover, CD28 is the critical T cell costimulatory receptor that provides the cell the important second activation signal by binding CD80 and CD86 which are expressed by antigen presenting cells. In addition to its co-stimulation role, CD28 functions by preventing T cells from entering an anergic-hyporesponsive state or from undergoing premature apoptotic cell death. In murine peripheral lymphoid organs and in the blood, all CD4+ and CD8+ T cells express CD28. In the thymus, CD28 expression is highest on immature CD3-, CD8+ and CD4+8+ cells, and on CD4-8- cells that express alpha/beta and gamma/delta TCR. The level of CD28 on mature CD4+ and CD8+ alpha/beta TCR+ thymocytes is two- to fourfold lower than on the immature cells. Diseases associated with CD28 dysfunction include mycosis fungiodes and Sezary's Disease.