Invitrogen™ Human CD28 (aa 180-220) Control Fragment Recombinant Protein

Description

Highest antigen sequence indentity to the following orthologs: Mouse (80%), Rat (80%). This recombinant protein control fragment may be used for blocking experiments with the corresponding antibody, PA5-84832 (PA5-84832. In IHC/ICC and WB experiments, we recommend a 100x molar excess of the protein fragment control based on the concentration and the molecular weight. Pre-incubate the antibody-protein control fragment mixture for 30 min at room temperature.

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.