Plasma Cells – A Closer Look at Their Origins, Functioning and Possible Issues
Plasma cells are lymphocytes that produce high levels of antibodies. They originate in the bone marrow and they develop from B cells into plasma cells in lymph nodes. Pending departure from the bone marrow, B cells function as antigen-presenting cells. The antigen is processed by the B cell through endocytosis.
The gathered information transforms the B cell into a specialized plasma cell after it reaches a lymphatic node. As a development stage, a B cell turns into a plasma blast and further develops into a plasma cell. A plasma blast produces fewer antibodies but is capable of dividing rapidly and incorporating antigens. At this stage, it either continues to fuel T cells with information to stimulate other B cells, or it fully matures into a specialized plasmatic cell.
Plasma cells are no longer able to switch between antibody classes and continue to serve and produce high levels of antibodies in the time span of a few weeks to a few months. They are basically produced when an antigen is detected in high enough quantity to warrant the presence of high numbers of lymphocytes to actively correct it.
The actual life span of plasma cells is determined by the continued presence of the antigen they need to respond to. B cells need to encounter the specific antigen and deliver information to other B cells in order to keep the specific plasma flow needed to topple it. When B cells no longer encounter that antigen, they begin to specialize on other antigens, if present, and T cells no longer share the information to produce plasma cells to that specific antigen.
A separate process of stimulating B cells, without T cells functioning as an intermediary, results in short-lived cells that generate IgM antibodies. As a part of the responsive humoral immune system, plasma cells, although limited to a single antigen response, create an abundant flow of antibodies tweaked to their specific antigen.
In the case of multiple myeloma, plasma cells are the original cause, namely it is plasma cells that continue to produce excess antibodies when they are no longer needed by the lymphatic system. The excess antibodies are known as paraproteins, which lead to paraproteinemia. The counterpart of the excess of antibodies is the immunodeficiency that occurs when the plasma cells are not producing the required amounts of antibodies.
To sum it all up, lymphocytes are based on T cells and B cells. B cells serve to gather information on antigens, T cells attack any detected antigens, while requesting a special antibody producing function from the B cells. An antigen is virtually any substance that is foreign to the blood stream. Upon detection, antibodies are produced with a structure that fits the external structure of the antigen to neutralize it. The antibody is a protein, one of the millions present in our bloodstream, that is made to specifically counteract a certain antigen.
Thus, T cells are divided into killer T cells, that are capable to recognize and destroy a certain known pattern of antigens, and helper T cells determine the development and lifespan of the body’s antibody functions. Plasma cells depend on the latter to be directed and created.
The immune system is a complex part of our body, one that functions by rules similar to the wild nature outside, rather than the inner workings of the human body.
The immune system will likely produce high random specialized T cells to counteract antigens that may have never been present in the blood stream, while producing B cells only as a reactive method to an unknown antigen. It will produce auto tolerant proteins but kill or paralyze self-recognizing proteins in the embryonic stage.
The human body does not mind wastefulness and seems to have become aware of these cells’ purposes. Self recognizing antibodies inherited from the father and self recognizing antibodies inherited from the mother would be incompatible. We may think of the random, unneeded proteins produced by the body as wasteful, but the immune system sees them as an efficient method of first defense against antigens.
As plasma cells are proof of, the immune system has innate random responses, just as well as informed responses.