Immunity to Infection

Anders Elm Pedersen, University of Copenhagen, Copenhagen, Denmark

Published online: September 2007

DOI: 10.1002/9780470015902.a0000478.pub2

The immune system comprises innate and adaptive immune responses coordinated to prevent infection. Innate immune responses are early responses based on preformed cells and effector molecules with a limited repertoire of antigen receptors. In contrast, adaptive immune responses take several days to mount, but take advantage of a very large repertoire of antigen receptors and comprises memory. The immune system must constantly face pathogen invasion strategies and at the same time avoid destruction of non-infected host tissue. In the following review the role of the various components of the immune system and their role in immunity to infections is described.

Keywords: infection; innate immune response; acquired immune response; humoral immune response; cellular immune response

Figure 1. Innate and adaptive immune responses. Macrophages, neutrophils and natural killer cells are attracted to the site of pathogen entry. Dendritic cells take up antigen and migrate to regional lymph nodes. Here antigen presentation to T cells take place, and these differentiate into helper T cells (TH1 or TH2 CD4 T cells) and cytotoxic T cells (CD8 T cells). Activation of B cells and immunoglobulin production are also initiated.
Figure 2. Major histocompatibility complex molecules. MHC class I molecules present peptides derived from intracellular antigens to CD8 T cells. Also the presence of MHC-I molecules on the cell surface prevents attack by natural killer cells. In contrast, MHC class II molecules present peptides from extracellular antigens and present these to CD4 T cells.
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 Further Reading
    Cresswell P (1995) Assembly transport and function of MHC class II molecules. Annual Review of Immunology 12: 259–293.
    book Janeway CA and Travers P (2005) Immunobiology, 6th edn. New York: Garland.
    book Murray PR, Rosenthal KS, Kobayashi GS and Pfaller MA (1998) Medical Microbiology, 3rd edn. St Louis, MO: Mosby Year-book.
    book Paul WE (2003) Fundamental Immunology, 5th edn. New York: Lippincott-Raven.
    Ploegh HL (1998) Viral strategies of immune evasion. Science 280: 248–253.

Related Sub-Topics:

Infection | Acquired (Adaptive) Immunity | Innate Immunity | Medical Microbiology
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Article Title: Immunity to Infection
 
How to Cite close
Pedersen, Anders Elm(Sep 2007) Immunity to Infection. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0000478.pub2]