Adaptive immunity saves our lives from dangerous infections!
Any kind of severe defective immune system will increase the morbidity of a person. An immunocompromised person needs protection from bacteria, viruses, fungi and lots of other parasites.
Adaptive immunity is a more sophisticated defense mechanism than the innate immunity, though they are interlinked in a way that, they work together in a finely tuned routine. Innate response is the trigger for the adaptive immunity to become active and come to our defense.
Some important characteristics of Adaptive immunity are:
1. It is highly specific. Meaning, it has specific receptors and responses tuned a particular pathogen.
2. Adaptive immunity is characterized by having memory. That is once a person recovers from an illness that person is provide with (arguable) a life time protection against the disease. For example, chicken pox, measles and so on.
3. It is characterized by having a large diversity. This is due to recombination of genes that produces the antibodies.
4. Adaptive immunity, just like innate immunity has some kinds of barriers, these barriers provide interim protection from the pathogen if they somehow managed o enter the body. For example, cutaneous and mucosal immune barriers, also secrete antibodies that roam in the blood stream trying to eliminate pathogens.
5. The adaptive immune system has Lymohocytes ( B cells and T cells ) that carry out the cell mediated attack on harmful pathogens in the body.
6. This immune system is also conditioned to recognize Self from Non Self. That is the T cells and B cells have the capability to recognize the cells of the body against those that have arrived from outside.
7. The adaptive immunity is also called acquired immunity. It works in three stages : the recognition stage, the activation stage and the effector stage.
8. The adaptive immune system takes time to get fully activated. That is this time is utilized to multiply the required cells for the process of elimination.
9. It also has the property of clonality- this is the process where the when a particular lymphocyte recognizes a pathogen, that particular lymphocyte is selectively amplified. This amplification helps in mounting a greater and specific attack on the pathogen.
The responses of adaptive immunity is often destructive, that is the reason for the responses to recognize self from non-self / foreign. Other reactions that happens when the immune system encounters a foreign entity are allergic conditions like hay fever, boils, asthma or they can even mount a inflammatory responses. Innate immune system helps the adaptive system to distinguish between different classes of pathogens and then recruit an effective response against the pathogen by the adaptive immunity. This system of co-operation is called Pathogen associated immunostimulants.
Antigen is the name given to any foreign entity that cause a reaction from the adaptive immune system. It is short for Antibody generator. The process of introducing an antigen inside the body to generate a adaptive immune response is called Immunization, this is the principle behind vaccinations.
Adaptive immunity can choose to react via the
(1) Cell mediated response that is the T cells, which is divided into Helper T cells and Cytotoxic T cells.
(2) Antibody mediated response— these are generated by the B cells , the b cells produces antibodies, immunoglobulins, which circulate the bloodstream and even cross barriers like the mucous or cutaneous.
They bind to the foreign entity and signals the other cells and elements of the immune system to mount a heavy attack on the foreign body. They also facilitate the macrophages, phagocytic cells to ingest the pathogen. Some examples of antibodies are – IgA, IgM, IgG, IgE and IgD.
