Which is the cell actively participate during allergy?
Answers
The innate immune system regulates the body’s initial response to pathogen exposure and is responsible for catalysing the sensitisation process which leads to allergic reactions. This is a non-specific response which involves recognition of molecules entering the body that are shared by a group of pathogens. The immune system recognises these molecules because they are not found in the cells of the human body. This type of immune reaction is distinct from the reactions which occur in recognition of specific pathogens such as salmonella.
Innate immunity is developed in the human body at birth and does not adapt or improve with ageing, unlike acquired immunity which develops throughout life as a result of pathogen exposure. For example, the skin and mucosa are tough, intact anatomical barriers which provide innate immunity and are in place at birth, as are mechanisms for mechanical removal of pathogens (e.g. sneezing and coughing, vomiting, mucus removal). On the other hand, antibodies to pathogens like salmonella only develop upon exposure to those pathogens, for example when an individual eats food contaminated with salmonella.
While anatomical barriers of the innate immune system can be seen with the naked eye, the innate immune system also functions at the cellular and molecular level. Important cells and molecules involved in innate immune responses include:
Phagocytic cells which are white blood cells and include neutrophils, eosinophils and macrophages. These cells are attracted to foreign pathogens in the body by inflammation and remove harmful pathogens in the blood by ingesting them;
Inflammatory mediators including basophils and mast cells. These cells regulate the body’s inflammatory responses and signal the body to mount an inflammatory response if a foreign particle invades. The inflammatory response catalyses other immune responses, such as activation of phagocytic cells;
Natural killer cells which are also involved in adaptive immune processes. In the innate immune system these cells recognise cells under stress or invasion from pathogens and binds to them. The natural killer cells are capable of inducing apoptosis (death, or the last phase of the cell cycle) in the stressed cells and the pathogens they contain; and
Molecules including complement proteins and cytokines. Molecules are produced by the cells of the human body but also influence responses of the immune system. For example, cytokines are pro-inflammatory, meaning that they stimulate inflammatory processes
Answer:
Explanation:
Secreted IgE circulates in the blood and binds to an IgE-specific receptor (a kind of Fc receptor called FcεRI) on the surface of other kinds of immune cells called mast cells and basophils, which are both involved in the acute inflammatory response. The IgE-coated cells, at this stage, are sensitized to the allergen.