Organ transplant is a common practice in the medical field and can involve the transplant of various types of body organs. Sometimes these organs are rejected by the body when they're transplanted from one person to another.
The reason that these organs are sometimes rejected is because of cytotoxic T cells. This happens because T cells notice that the cells of that organ don't have the proper MHC markers. As a result, the cytotoxic T cells attack and kill the transplanted organ's cells.
MHC markers are markers found on the surface of our cells' plasma membranes. They give the immune system a window to the inside of the cell to make sure our cells are not infected. MHCs also mark the cell as "self," so that our immune system knows not to attack healthy cells. When an organ is transplanted, sometimes those MHC markers won't match; cytotoxic T cells will recognize that and attack the transplanted organ's cells.
MHC markers are specific to each person, but sometimes one person's MHC markers can be similar enough to another person's that the body won't really recognize the difference.
Some steps that are taken before a transplant can be important in making sure that the transplant is accepted:
Post surgery, drugs are generally given to the recipient. These drugs will suppress the immune system so that it does not respond to the new organ. This allows the body to acclimate to this new organ and accept it.
The main concept of immunotherapy is to use the body's own immune mechanisms and manipulate those as treatments for diseases. Immunotherapy uses two common processes:
Cancer occurs when one of our body's own cells mutates and divides uncontrollably. What makes cancer so difficult to combat is the fact that cancerous cells still look our own body's cells to our immune system, and therefore, we don't fight cancer like we do other diseases.
Cytokines will activate B cells and T cells within the body. Cytokines are often used to treat different types of cancers.
Interferons are a type of cytokine that virus-infected cells release. When a cell has been infected by a virus, it will release these interferons into the body. Normal cells will respond to the release of these interferons by producing a substance that won't allow the virus to multiply. These are used commonly in the treatment of hepatitis C and multiple sclerosis.
3b. Monoclonal Antibodies
Monoclonal antibodies are antibodies that are made in a lab by cells that have been cloned from a single plasma cell or B cell
Monoclonal antibodies can recognize and bind to specific antigens. They are used commonly in home pregnancy tests because they can detect small amounts of a certain hormone only produced when a woman is pregnant.
How are commercial antibodies made?
The first step is to recruit an immune system with all its millions of randomly-generate antibody-producing cells. Thus, a mouse is injected with one of a pathogen's many antigens (unique chemical markers), which causes the mouse to select the correct antibody and mass-produce it.
The monoclonal antibody-forming cells will be isolated from the mouse. In some cases, an antibody-forming cell is going to be combined with a tumor cell to form this type of hybrid, which will then produce desired antibodies. Clones will be made of that hybrid; then those antibodies will be isolated.
Sometimes the gene for this antibody can be cloned into a bacteria, which will produce the monoclonal antibody faster and cheaper.
Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND