|MadSci Network: Immunology|
Lymphocytes have the same parts as most other cells in our bodies, cell membrane, cytoplasm and nucleus. However, lymphocytes have a very special feature that is important for their function. Lymphocytes are designed to patrol the body looking for things that are not part of the normal self. Some examples are bacteria, viruses, cells infected with viruses, and cancer cells. In order to recognize these things, the lymphocytes have “antigen receptors”, and each lymphocyte can recognize a different antigen. We have millions of lymphocytes so that our immune system can usually recognize these intruders and we usually win the battle. (Not always though, because some viruses and tumor cells are very tricky) There are two major types of lymphocytes, B cells that can make antibody to stop the bacteria and viruses, and T cells that can kill virus infected cells or cancer cells. The antigen receptor on B cells is antibody, and the antigen receptor on T cells is called the T cell receptor. They are shown in the Figure, but the antigen receptors are shown much bigger than they really are compared to the size of the cell. Again, the important thing is that each lymphocyte can have a different antigen receptor so we are protected against most potential problems. Figures are from Immunology 5th Edition, Goldsby et al. Copyright WH Freeman
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