CD8beta Antibody [EP42] (FITC)

In the chicken, the CD8 molecule is present in two forms - (i) a homodimer of two alpha chains and (ii) a heterodimer of an alpha chain and a beta chain. While the vast majority of CD8+ cells in the thymus, spleen, and blood of adult chickens express both CD8alpha- and CD8beta-chains, a relatively large proportion of the CD8+ TCR-gammadelta cells in the spleens of embryos and young chicks express only the alpha-chain of CD8. Among intestinal epithelial lymphocytes, the major CD8+ T cell populations present in mice are conserved but there is a population of TCR-gammadelta CD8alphabeta cells in the chicken that is not found in rodents. Chicken CD8 is expressed on approximately 80% of thymocytes, 45% of blood mononuclear cells, and 50% of spleen cells but less than 1% of cells in the bursa and bone marrow. The monoclonal antibody EP42 recognizes the CD8beta chain.