Dictionary > Immune response

Immune response

Immune response definition

Immune response
n., ɪˈmjuːn ɹɪˈspɒns
A reaction of the body in response to the presence of a foreign substance (i.e. antigen)

Immune Response Definition

An immune response is defined as the reaction of the body in response to the presence of a foreign substance (i.e. antigen).


An immune response pertains to any of the body’s response to a foreign substance, such as an antigen. (Ref. 1) The response intends to protect the body from disease-causing viruses, fungi, bacteria, and parasites. A transplanted organ may also incite an immune response when it is identified as non-self. (Ref. 2)

In vertebrates, including humans, an immune response may be in the form of antibody production, induction of cell-mediated immunity, complement activation, or development of immunological tolerance. (Ref. 3)

Referred to as humoral immune response, this form of response is characterized by the formation of humoral antibodies following an antigenic challenge. (Ref.4) B cells produce antibodies that are specific to antigens so that the next time these antigens are present in the body the antibodies will be able to recognize them and eventually neutralize them. In
In cell-mediated immunity, the response of the body against antigens involves the activation of macrophages and NK cells, the production of cytotoxic T cells that are antigen-specific, and the release of cytokines. (Ref. 5)

A lack of an effective immune response may lead to disorders. One of them is autoimmunity where the body mistakes its own substances and tissues as antigens. This condition leads to autoimmune diseases, e.g. Celiac disease, systemic lupus erythematosus, and diabetes mellitus type 1. Another is gammopathy. Gammopathy is an immune disorder characterized by an abnormal proliferation of cells producing immunoglobulins. (Ref.6)

See Also


  1. antigen | Definition, Function, Types, & Facts | Britannica. (2020). In Encyclopædia Britannica. https://www.britannica.com/science/antigen
  2. | British Society for Immunology. (2015). Immunology.Org. https://www.immunology.org/policy-and-public-affairs/briefings-and-position-statements/transplant-immunology
  3. Lackie, J. (2007). The dictionary of cell and molecular biology. Amsterdam Boston: Elsevier. p.213.
  4. Janeway, C. A., Travers, P., Walport, M., & Shlomchik, M. J. (2016). The Humoral Immune Response. Nih.Gov; Garland Science. https://www.ncbi.nlm.nih.gov/books/NBK10752/
  5. Kaiser, G. (2019). Cell-mediated immunity – an overview. In Bio.Libretexts.org. https://bio.libretexts.org/Bookshelves/Microbiology/Book%3A_Microbiology_(Kaiser)/Unit_6%3A_Adaptive_Immunity/14%3A_Cell-Mediated_Immunity/14.1%3A_Cell-Mediated_Immunity_-_An_Overview
  6. Rison, R. A., & Beydoun, S. R. (2016). Paraproteinemic neuropathy: a practical review. BMC Neurology, 16(1). https://doi.org/10.1186/s12883-016-0532-4

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