How the Immune System...
Provides an immediate and nonspecific immune response...
The nonspecific or innate immune system is the first line of defense against an foreign invader into your body, and its first response to infection is inflammation. The nonspecific immune system doesn't have a specific defense for different pathogen invaders, rather, it is like a immediate "emergency lock-down" button that always responds quickly and always in the same, generic way. When an invading pathogen damages a cell, the cell releases information to the body and we form a barrier to stop further spread of the infection, and also repair anything damaged. There are many white blood cells present in the innate immune system line of defense...
Some key cells would be phagocytes and macrophages, which envelope pathogens in their endosomes and move them to the lysosome, which has enzymes and acids which will destroy the pathogen.
Dendritic Cells are also very important since they reside at the skin, and stop bacteria from simply waltzing through to your body wrecking havoc.
Mast cells protect against and heal wounds in the body also.
A simple diagram of the macrophage, notice how it has receptors that trigger it to engulf pathogens when it comes in contact with invaders.
A country at War - A Dystopian Short Story By Sean Yang
To think of a real life scenario...Imagine a country that has suddenly been invaded by foreign enemies. The dendritic cells, or the border patrols, in this case, would try to stop as many bad guys as possible. When the enemies broke through and integrated themselves into the ranks of the country, the whole country enters systematic lock-down (inflammation) and the secret police (phagocytes and macrophages) begins to hunt down the invaders and escort them in a van (endosomes) to the execution range where they will be killed (lysosomes). Because the invaders have already destroyed parts of the country, aid groups (mast cells) are sent out to reconstruct the city and heal injured people (cells).
Continued in the next section...
Activates T and B cells in response to an infection
T and B lymphocytes are all made in the bone marrow. B cells simply lie dormant until a antigen attaches to it, which then causes it to trigger and eats the antigen. After the B cell eats its antigen, it leaves parts of the antigen stuck to his MHC (major histocompatibility complex) molecules which are unique to each B cell.
The T cell will then look for B cells that have already digested antigens and have antigen parts. The T cells will then move in to support the B cell by producing cytokines which could help the B cell to become antibodies. The T cells themselves are created from the thymus and also switch forms to have many functions. Some continue to produce cytokine that attract macrophages and other white blood cells, and some track down infected cells.
2 good diagrams that really explains the relationship between T and B cells well
Now...ongoing with my scenario...its a little graphic but it really captures the essence of T and B cells
With the invaders now present in the borders of the country, the government realized that it needs to mobilize the national army. The government sent convoys of troops (B cells) around the country and set up many ambushes to take out the invaders. When a convoy captures a group of invaders (antigens), the troops chop off the invaders' heads (antigen fragments) and stick it on a unique pike (MHC molecules) so that the new eager army recruits (T cells) can see. The new recruits, invigorated by the presence of soldiers who just decapitated the enemy and heads on pikes, start to work double time on creating new weapons (cytokines) for the army. The new weapons (cytokines) will be used to train more recruits (T cells). Experienced recruits also get some field work such as providing support on the war zone to the secret police (macrophages) or track down invaders themselves.
Continued in the next section...
Responds to later exposure to the same infectious agent
A simple graph that illustrates how the white blood cells in your body learn to fight off similar antigens quickly. As you can see above, the second exposure of antigen A received a far more effective antibody response.
When pathogens invade into a body, not all B cells will be triggered by an encounter with an antigen, and so the rest of the excess "naive" B cells will undergo clonal selection to form clusters of cells that are specific for fighting against the antigen. Although most of the cloned B cells will differentiate, some become important memory B cells which can survive for ten years. The memory B cells have a specific amino acid sequence that binds well to the antigen called the paratope. So when the same antigen invades again, the memory B cells with the accustomed paratopes will kill the antigens much much faster than the first encounter. Memory T cells also work this way and could be used to fight cancer; if they are able to recognize foreign invaders such as cancer cells, they will head out and kill them.
A picture showing the naive B cell becoming a memory B cell
The war is over, the country is devastated, but intact. Remaining soldiers that have not been deployed or encountered enemies (B cells) are put through a special training program (clonal selection) to become skilled, experienced and specialized fighters (memory B cells) to counter a possible future invasion. The government have also developed special weapons (paratope) for the special forces that causes immense harm to the enemy should they come again. Leftover recruits can also attend this intense training regimen (T memory cells). The government has also staged multiple harmless drills that simulate an invasion (vaccines) in order to get the army prepared for a possible future invasion.
Distinguishes Self From Non-self
Our antibodies belong to our body, and they know that also. To prevent our own cells from starting an outright civil war with each other, our cells have distinctive epitopes (shapes) that causes the cells to identify with each other. When pathogens invade, the antigens all have different epitopes and therefore our white blood cells are able to determine that they are of a foreign source and begin to attack. When a foreign antigen is discovered, a antibody latches itself onto it and activates the phargocytes to eat it. Allergy is a result of the body's immune system reacting to a seeming harmless substance, such as the smell of a freshly printed Biology test or cat hair. When allergy happens, there aren't any antigens; rather, they are called allergens.
A picture showing antibodies (the Y shapes) attaching themselves to specific epitopes.
With the numerous cases of friendly fire and the mistreatment of citizens by the army during the war, the government has issued flags to everyone belonging to the country and also told all the people (cells) to raise their flags when in contact with others. There has still been numerous cases of friendly fire when soldiers accidentally set their flags on fire when attempting to light their cigarettes.
The End
Provides an immediate and nonspecific immune response...
The nonspecific or innate immune system is the first line of defense against an foreign invader into your body, and its first response to infection is inflammation. The nonspecific immune system doesn't have a specific defense for different pathogen invaders, rather, it is like a immediate "emergency lock-down" button that always responds quickly and always in the same, generic way. When an invading pathogen damages a cell, the cell releases information to the body and we form a barrier to stop further spread of the infection, and also repair anything damaged. There are many white blood cells present in the innate immune system line of defense...
Some key cells would be phagocytes and macrophages, which envelope pathogens in their endosomes and move them to the lysosome, which has enzymes and acids which will destroy the pathogen.
Dendritic Cells are also very important since they reside at the skin, and stop bacteria from simply waltzing through to your body wrecking havoc.
Mast cells protect against and heal wounds in the body also.
A simple diagram of the macrophage, notice how it has receptors that trigger it to engulf pathogens when it comes in contact with invaders.
A country at War - A Dystopian Short Story By Sean Yang
To think of a real life scenario...Imagine a country that has suddenly been invaded by foreign enemies. The dendritic cells, or the border patrols, in this case, would try to stop as many bad guys as possible. When the enemies broke through and integrated themselves into the ranks of the country, the whole country enters systematic lock-down (inflammation) and the secret police (phagocytes and macrophages) begins to hunt down the invaders and escort them in a van (endosomes) to the execution range where they will be killed (lysosomes). Because the invaders have already destroyed parts of the country, aid groups (mast cells) are sent out to reconstruct the city and heal injured people (cells).
Continued in the next section...
Activates T and B cells in response to an infection
T and B lymphocytes are all made in the bone marrow. B cells simply lie dormant until a antigen attaches to it, which then causes it to trigger and eats the antigen. After the B cell eats its antigen, it leaves parts of the antigen stuck to his MHC (major histocompatibility complex) molecules which are unique to each B cell.
The T cell will then look for B cells that have already digested antigens and have antigen parts. The T cells will then move in to support the B cell by producing cytokines which could help the B cell to become antibodies. The T cells themselves are created from the thymus and also switch forms to have many functions. Some continue to produce cytokine that attract macrophages and other white blood cells, and some track down infected cells.
2 good diagrams that really explains the relationship between T and B cells well
Now...ongoing with my scenario...its a little graphic but it really captures the essence of T and B cells
With the invaders now present in the borders of the country, the government realized that it needs to mobilize the national army. The government sent convoys of troops (B cells) around the country and set up many ambushes to take out the invaders. When a convoy captures a group of invaders (antigens), the troops chop off the invaders' heads (antigen fragments) and stick it on a unique pike (MHC molecules) so that the new eager army recruits (T cells) can see. The new recruits, invigorated by the presence of soldiers who just decapitated the enemy and heads on pikes, start to work double time on creating new weapons (cytokines) for the army. The new weapons (cytokines) will be used to train more recruits (T cells). Experienced recruits also get some field work such as providing support on the war zone to the secret police (macrophages) or track down invaders themselves.
Continued in the next section...
Responds to later exposure to the same infectious agent
A simple graph that illustrates how the white blood cells in your body learn to fight off similar antigens quickly. As you can see above, the second exposure of antigen A received a far more effective antibody response.
When pathogens invade into a body, not all B cells will be triggered by an encounter with an antigen, and so the rest of the excess "naive" B cells will undergo clonal selection to form clusters of cells that are specific for fighting against the antigen. Although most of the cloned B cells will differentiate, some become important memory B cells which can survive for ten years. The memory B cells have a specific amino acid sequence that binds well to the antigen called the paratope. So when the same antigen invades again, the memory B cells with the accustomed paratopes will kill the antigens much much faster than the first encounter. Memory T cells also work this way and could be used to fight cancer; if they are able to recognize foreign invaders such as cancer cells, they will head out and kill them.
A picture showing the naive B cell becoming a memory B cell
The war is over, the country is devastated, but intact. Remaining soldiers that have not been deployed or encountered enemies (B cells) are put through a special training program (clonal selection) to become skilled, experienced and specialized fighters (memory B cells) to counter a possible future invasion. The government have also developed special weapons (paratope) for the special forces that causes immense harm to the enemy should they come again. Leftover recruits can also attend this intense training regimen (T memory cells). The government has also staged multiple harmless drills that simulate an invasion (vaccines) in order to get the army prepared for a possible future invasion.
Distinguishes Self From Non-self
Our antibodies belong to our body, and they know that also. To prevent our own cells from starting an outright civil war with each other, our cells have distinctive epitopes (shapes) that causes the cells to identify with each other. When pathogens invade, the antigens all have different epitopes and therefore our white blood cells are able to determine that they are of a foreign source and begin to attack. When a foreign antigen is discovered, a antibody latches itself onto it and activates the phargocytes to eat it. Allergy is a result of the body's immune system reacting to a seeming harmless substance, such as the smell of a freshly printed Biology test or cat hair. When allergy happens, there aren't any antigens; rather, they are called allergens.
A picture showing antibodies (the Y shapes) attaching themselves to specific epitopes.
With the numerous cases of friendly fire and the mistreatment of citizens by the army during the war, the government has issued flags to everyone belonging to the country and also told all the people (cells) to raise their flags when in contact with others. There has still been numerous cases of friendly fire when soldiers accidentally set their flags on fire when attempting to light their cigarettes.
The End
