type 2 immune response

Definition

Target type: biologicalprocess

An immune response which is associated with resistance to extracellular organisms such as helminths and pathological conditions such as allergy, which is orchestrated by the production of particular cytokines, most notably IL-4, IL-5, IL-10, and IL-13, by any of a variety of cell types including T-helper 2 cells, eosinophils, basophils, mast cells, and nuocytes, resulting in enhanced production of certain antibody isotypes and other effects. [GOC:add, ISBN:0781735149, PMID:18000958, PMID:18007680, PMID:20065995, PMID:20200518]

Type 2 immune responses are a critical component of the host defense against a variety of pathogens, particularly helminth parasites and certain allergens. These responses are characterized by the activation of specific immune cells and the production of distinct cytokines that orchestrate a multifaceted protective mechanism.

The initiation of type 2 immune responses begins with the recognition of specific antigens, such as those associated with helminths or allergens, by specialized immune cells called dendritic cells (DCs). These DCs, upon antigen capture, migrate to lymph nodes, where they present the antigen to naive T lymphocytes.

The presentation of antigen by DCs in the context of specific costimulatory molecules and cytokines, particularly IL-4, skews the differentiation of naive T cells into T helper 2 (Th2) cells. Th2 cells are the central orchestrators of type 2 immune responses. They produce a characteristic suite of cytokines, including IL-4, IL-5, and IL-13.

IL-4 plays a pivotal role in promoting the differentiation of naive T cells into Th2 cells. It also stimulates the production of IgE antibodies by B cells. IgE antibodies bind to mast cells and basophils, which are effector cells crucial for type 2 immune responses.

IL-5 acts as a growth and differentiation factor for eosinophils, a type of white blood cell that plays a central role in eliminating helminths. Eosinophils are recruited to the site of infection by IL-5 and release cytotoxic granules containing proteins that damage and kill helminths.

IL-13, along with IL-4, promotes the production of mucus, which can trap and expel pathogens from the body. IL-13 also contributes to tissue remodeling and repair, which is important for restoring tissue integrity after an infection.

In addition to their direct effects on immune cells, type 2 cytokines also influence the activity of other cells and tissues. For example, IL-4 and IL-13 can modulate the activity of epithelial cells, smooth muscle cells, and fibroblasts.

Type 2 immune responses are essential for protecting the host from a variety of pathogens. However, these responses can also be dysregulated, leading to allergic diseases such as asthma, eczema, and food allergies. In these cases, the immune system mounts an inappropriate response to otherwise harmless allergens, resulting in tissue damage and inflammation.

Therefore, understanding the intricate mechanisms of type 2 immune responses is crucial for developing novel therapies to combat infectious diseases and allergic disorders.'
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Proteins (2)

Compounds (4)