General description
Millipore’s FlowCellect Human CD4/CD8 T Cell Assay provides a rapid and simple method to asses the percentage of CD4 and CD8 T cells. The CD8-FITC/CD4-PE/CD3-PECy5 cocktail consists of three anti-human antibodies CD3-PECy5, CD4-PE, and CD8-FITC which enables the researcher to obtain percentages of mature human T lymphocytes (CD3+),helper/inducer (CD3+CD4+) T lymphocytes, and suppressor/cytotoxic (CD3+CD8+)T lymphocytes in erythrocyte-lysed whole blood. The CD3 antibody Anti-CD3, UCHT1, reacts with the ε-chain of the CD3 part of the TCR/CD3 complex. CD3 is a pan-T marker expressed by normal and neoplastic T cells and uniquely allows the identification of all T cell lymphocytes. The CD4 antibody allows the identification of human helper/inducer CD4+ T cell (HLA Class II reactive) and recognizes a 60,000 Da surface antigen. Monocytes also express CD4 but at lower density, and have no co-expression of CD3 and hence can be distinguished away from CD4 T Cells in this kit. The CD8 antibody allows the identification of CD8, a 68 kDa transmembrane glycoprotein expressed by class I major histocompatibility complex restricted, mature suppressor/cytotoxic T cells, the great majority of cortical thymocytes and approximately 30% of medullary thymocytes. In addition a proportion of γδ T cells and NK cells express CD8. Inclusion of the CD3 antibody allows for the unique identification of the CD8 cytotoxic T Cells
The kit can thus distinguish both the CD4 T helper cells as well as the CD8 cytotoxic T Cells. The entire assay can be preformed in 35 minutes in a simple no wash manner thus allowing for percentages and absolute counts simultaneously when using the easyCyte HT System.
T cell lymphocytes (CD3+) constitute more than % of circulating lymphocytes and play a central role in both humoral and cell-mediated immunity. CD3 T cell can be further broadly classified as T helper lymphocytes that are CD3+CD4+ and cytotoxic T lymphocytes that are CD3+CD8+. Identification and enumeration of CD3 T lymphocytes, CD4 T lymphocytes and CD8 T lymphocytes is important in many immunological experiments that involve T cell characterization or study of T cell function. These studies may range from immunophenotyping experiments, studying T cells during development and disease or understanding impacts on T cells on treatment with specific compounds or mitogens or evaluating T cell specific responses. T lymphocytes (T cells) play critical roles in the regulation of immune responses, and are responsible for mediating many of the effector mechanisms of the immune system. Multiple studies have identified the identification and enumeration of CD4 T helper cells to be important in characterizing and monitoring immunodeficiency such as HIV, immunosuppression, and autoimmune diseases. Changes in T cell populations have also been implicated in chronic inflammation associated with the disease states such as cancer and atherosclerosis as well as in viral infection, bacterial infections, parasitic infections, sepsis, tuberculosis, burns, trauma, malnutrition, and stress. Similarly, identification and enumeration of CD3+, CD8+ populations are also useful in characterizing or monitoring autoimmune diseases and immune reactions such as transplant rejection, graft-versus-host disease and systemic lupus erythermatosus. People that have severe combined immunodefiencies or congenital or acquired immune defiencies often have an elevation in their CD8+ subset. A monitoring of both the CD4+ and CD8+ lymphocyte counts has also been be an important factor to predict the clinical prognosis of severe hepatitis patients.