Because white blood cells are so important to the immune system, they are used as a measure of immune system health. A normal white blood cell count is in the range of 4,000 to 11,000 cells per microliter of blood. An article like this one can help you learn more about white blood cells in general and the different types of white blood cells found in your body. In humans these molecules are encoded by several genes all clustered in the same region on chromosome 6. As a result, it is very rare for two individuals to have the same set of MHC molecules, which are collectively called a tissue type.
MHC molecules are important components of the immune response.
They allow cells that have been invaded by an infectious organism to be detected by cells of the immune system called T lymphocytes, or T cells. The T cell recognizes the foreign peptide attached to the MHC molecule and binds to it, an action that stimulates the T cell to either destroy or cure the infected cell. However, if the immune mechanism malfunctions and T cells react against self peptides, an autoimmune disease arises. See this article and this article for additional details. Inc. All rights reserved.