CDAntigens

Abstract

CD (clusters of differentiation) antigens are molecules originally defined as being present on the cell surface of leucocytes and recognised by specific antibody molecules, but now including some intracellular molecules and molecules present on cells other than leucocytes. Such molecules are assigned a CD number following a consensus reached at regularly held international workshops. CD antigens include a large number of cell surface receptors, signalling molecules and adhesion molecules. Their identification is helpful in defining different populations and subpopulations of cells, particularly those of the immune system, in health and disease. Analysis of the surface phenotype of cells can be carried out on cell suspensions or using tissue sections. Methods are available for the in vitro enrichment or depletion of cells bearing a particular CD antigen, for example, from a mixed population of peripheral blood cells. CD antigens can be targeted in vivo by monoclonal antibodies for the treatment of tumours and autoimmune disease and to help limit graft rejection following transplantation. Key Concepts CD antigens are molecules that are mostly, but not exclusively, present on cell surfaces. They are defined using panels of monoclonal antibodies. CD designations are assigned at international workshops held every few years. There are over 300 different CD antigens characterised. They are mostly detected for the identification of populations and subpopulations of immune system cells. In some cases, they also have utility in the identification of tumours. Antibodies targeting CD antigens are used clinically in the treatment of tumours and autoimmune diseases and to limit the rejection of transplanted organs.

Quantification and Imaging of Antigens on Cell Surface with Lipid-Encapsulated Fluorescent Nanodiamonds

“…The surface of a cell is covered with various kinds of antigens [1]. These antigens are important molecular markers for the identification of different cell types and specific targets for the treatment of different diseases [2,3,4,5,6]. Red blood cells, for example, are classified as A, B, and O groups according to inherited differences in cell surface antigens composed of carbohydrates [4].…”

“…Red blood cells, for example, are classified as A, B, and O groups according to inherited differences in cell surface antigens composed of carbohydrates [4]. Human leukocyte antigens (or CD antigens), on the other hand, are proteins, and they play a central role in immune response [5]. The significance of these membrane-bound molecules has stimulated the development of an immunoenzymatic technique known as cell-enzyme-linked immunosorbent assay (cell-ELISA) to achieve quantitative analysis of cell surface antigens [7,8,9].…”