Humoral immunity is one of two ways the body seeks to protect itself from disease.
Humoral immunity is a means by which the body protects itself from infection by producing antibodies that target foreign material in the bloodstream that is considered potentially dangerous, marking it for destruction. It is part of the adaptive immune system, which is activated in response to a specific threat, as opposed to the innate immune system, which is continuously active but less effective. The other part of the adaptive system is cellular or cell-mediated immunity, in which cells release toxins to kill invaders or attack them directly, without the involvement of antibodies. Together, humoral and cellular immunities are designed to defend the body against a wide variety of threats that can compromise it.
How does it work
Over the years, humoral immunity has helped eradicate smallpox cases around the world.
This form of immunity begins in specialized white blood cells, known as B cells, which are produced by the bone marrow. They recognize antigens, which are certain molecules, such as some proteins, on the surface of a virus or bacteria. There are different types of B cells, each designed to respond to a specific antigen. When one is found, the B cell multiplies, producing a large number of individuals that release antibodies designed to bind to the antigen on the invading organism; they essentially become little antibody factories in the blood, floating around to attack as many invaders as possible. Once marked by these antibodies, the invaders will be destroyed by other immune cells.
A combination of antiretroviral drugs is needed to control HIV, rebuild humoral immunity, and prevent opportunistic infections.
When the invader is removed, many of the B cells produced to counter that particular threat will die, but some will remain, residing in the bone marrow and acting as a kind of “memory” for that attack. People are born with a set of innate immune responses designed to recognize different types of cells and organisms that can pose a threat to the body, but humoral immunity is acquired through exposure to viruses, bacteria, and other harmful substances. Over time, the body accumulates more “memories” from previous attacks by harmful microorganisms.
long term immunity
As flu viruses rapidly evolve, medical researchers must develop new vaccines each season.
The humoral immune response can produce long-lasting immunity to many infectious agents. When the body is attacked by an agent, such as a virus, that it hasn’t encountered before, it must start from scratch, and it usually takes several days to mount an effective immune response. During this time, the virus can multiply uncontrollably, causing an infection that can produce unpleasant and possibly dangerous symptoms. Only when the body has produced a large number of suitable antibodies can it fight the infection. However, if you do run into the virus again, you’ll usually be much better prepared, thanks to the retention of B cells produced in response to the previous attack, and can start working to eliminate the invader right away.
Vaccination
People undergoing chemotherapy must take precautions to avoid germs, since the treatments greatly reduce their immunity.
This immunological “memory” also works like vaccines and immunizations. People can be injected with dead or inactivated forms of a dangerous virus or bacteria that will stimulate a humoral immune response without posing any threat to the body. If, at some point in the future, that person is exposed to the real agent, there must be an immediate immune response to eliminate it before it can cause serious harm.
Without some form of immunity, either natural or artificial, infectious diseases can spread rapidly among family members and others in the community.
Vaccination is more effective for some types of infection than for others. A worldwide vaccination program against the smallpox virus achieved its complete extinction in nature, since it was unable to find a human host that was not immune. Unfortunately, some viruses mutate rapidly, causing changes in the compounds on their surface that the humoral immune system uses to recognize them. That is why new flu vaccines must be continuously developed. People vaccinated against this rapidly mutating virus may not be immune to a new strain that appears the following year because the chemicals on its surface have changed and will not be recognized as antigens by the body’s B cells.
immune system problems
Humoral immunity is a means by which the body protects itself from infection by producing that foreign material in the bloodstream.
When people develop problems with their humoral immunity, they are more susceptible to developing infections and diseases. Conditions like HIV directly attack the immune system to make it less functional. Immunity can also be compromised by the use of certain drugs, such as chemotherapy for cancer treatment and drugs used to prepare people for organ transplants. In people with compromised immune systems, prompt and aggressive treatment of any infection is to prevent the body from being overwhelmed by something it can’t fight off.
Vaccines are one step in creating humoral immunity.
Another problem that can occur with the immune system is autoimmune disease. Normally, the system is capable of chemically distinguishing between substances that are part of the body and those that are not, and will only respond to “foreign” substances. Sometimes, however, the system can mount an immune response to something that is a normal cellular component in the body, treating it in the same way as an invading organism. This results in tissue damage and is responsible for a number of serious diseases such as rheumatoid arthritis, lupus, and celiac disease.
The origin of the term
The term “humoral immunity” comes from the fact that this type of immunity is mediated by cells that float in the blood and lymph, or “humours” of the body. When researchers first began exploring the concept in the 19th century, many of them believed in medical theories dating back to ancient times, which included the idea that the balance of the body was maintained by substances flowing through the body and had various effects. While the humor theory has since been discredited, it persists in medical terminology.