The adaptive immune system has two major ways it reacts and these can be grouped as follows:
- Humoral – involves antibodies and used outside the cells (bodily fluids)
- Cell mediated – involves cells and used for protection inside tissue
Which approach is used mainly depends on the location and the type of invader. And though these approaches are distinct, they do work together and complement one another.
This section provides a brief examination of the main functions of each approach.
The immune system learns
Adaptive immunity is most effective if the immune system has previous knowledge of the pathogen. If a pathogen is met for the first time, the outcome of the encounter is recorded for future reference.
Humoral Immune Response
The humoral response is considered as the more simple of the two approaches. It is mainly driven by the activity of B Cells and co-ordinated by cytokines (inflammatory cells).
At any given time, there is a large variety of these cells traveling through our bodies.
Each individual B Cell is designed to act only against a specific foreign substance/invader (antigen). And they are are indirectly responsible for the production of antibodies.
If a specific B Cell encounters a matching antigen, it begins to multiply and develop into plasma cells (basically antibody production factories).
These plasma cells are then directly responsible for the rapid production of antibodies.
Antibodies are produced from protein and their job is to destroy and neutralize specific antigens (pathogens). But since they are produced as the result of the B Cells original encounter, they are only effective against the specific antigen first encountered by the B Cell.
Cell Mediated Immune Response
The cell mediated immune response is typically considered as the more advanced approach. It is driven by an immense variety of T Cells (T Lymphocytes), which perform a unique set of functions.
Similar to B Cells, individual T Cells travel through our bodies scouting for antigens that fit a specific description. And if an antigen is matched, the T Cell activates and goes to work.
It starts by quickly multiplying and sending signals to other parts of the immune system. During it’s multiplication, the original T Cell actually develops into the following:
- Helper T Cells – send signals and coordinate the immune response
- Killer T Cells – directly fight against the antigens
- Memory T Cells – record events for future reference
- Regulatory T Cells – control the process from getting out of control
This process results in an army of T Cells specifically created to fight against the encountered antigen. And overall, their approach is much more head-on than that of B Cells (which relies on antigens).
This section briefly examined the two major ways the adaptive immune system combats pathogens. Key points include:
- The adaptive immune response can be separated into two major approaches: humoral and cell mediated immunity
- Though the approaches are mainly used together, one typically dominates; which depends on the location and type of threat
- The humoral response primarily relies on B Cells and the production of antibodies to neutralize the discovered antigens
- The cell mediated approach primarily depends on T Cells and their ability to co-ordinate a direct fight against the antigens