The immune system consists of a series of mechanisms that protect our bodies from disease and tumors. To protect us, our immune system must be able to distinguish between harmful pathogens and healthy tissues. This task is complex, as many pathogens can have multiple versions and are often difficult to distinguish. Misdirection of the Immune System may occur when one or more types of immune cells fail to respond to a specific pathogen.
The most famous example of misdirection of the immune system is the infection of the human immunodeficiency virus (HIV). The virus affects CD4+ T cells in the immune system, which are equivalent to police sergeants. When the immune system tries to fight off an infection, it attacks the T cells. This is the cause of chronic immune system disorders, such as AIDS. The immune system is a compensatory system that can compensate for the weak or non-functional parts of the body. Misdirection of the immune system can cause autoimmune diseases, where antibodies form against body tissues.
When misdirection of the immune system occurs early in the healing process, the immune system becomes confused and begins attacking its own tissues. Antigen-presenting cells (APC) take debris from the wound to the local lymph node, where they interact with naive T-cells. When the signal is right, these cells become activated and divide rapidly to create more identical T-cells. Ultimately, the immune system destroys the red blood cells, which is what causes IMHA.
The misdirection of the immune system is another cause of psoriatic arthritis. The immune cells mistake the enthesium of the joint for an infection. This point is critical, because even a minor injury to the enthesium can trigger an attack by the immune cells. Therefore, any injury to this region can activate the psoriatic arthritis. The jury, after considering all the evidence, found that psoriatic arthritis is a misdirection of the immune system that interferes with the body's ability to fight infection.
Environmental factors such as pollution and food can affect the development of the immune system. For instance, fetal undernourishment has been linked to lifelong immune system impairment. Furthermore, the immune system is highly susceptible to misdirection of the body's innate immune response, which is designed to recognize safe environmental particles. In some cases, this can result in a life-threatening immune disorder affecting the gastrointestinal tract.
In an effort to avoid detection of non-self-antigens, pathogens hide in host cells and produce compounds to misdirect the immune response. In addition to this, some pathogens form biofilms and create surface proteins that can bind to antibodies. This allows the host immune system to respond more quickly to the antigen when it encounters it again. The immune system can respond to many pathogens, including bacteria.
When a cancer cell faces an attack, it can evolve a ligand called PD-L1 that binds to a PD-1 receptor on a T cell. The T cell then recognizes the ligand and stops attacking. It then self-destructs through apoptosis. This is how cancers control the immune system. PD-L1-ligand-containing cancer cells can misdirect the immune system and kill healthy cells.
Sources: