Definition
noun, plural: antigenic variations
(immunology) The changing of surface proteins by an infectious agent to evade a host immune response
Supplement
Antigenic variation is one of the ways by which an infectious agent evades a host immune response. For example, a pathogenic bacterium could alter its surface proteins and carbohydrates so as to circumvent the immune response of the host.
Antigenic variation makes the pathogen evade detection of the immune cells by altering their surface antigens. This gives the pathogen the advantage of repeatedly infecting the same host (re-infection) and therefore prolongs its stay within the host. It also increases the chance of being transmitted to a new host.
One of the immune responses of the host is to detect the surface antigens of the pathogen. Once detected, the immune cells would target the pathogen and destroy it. Some immune cells, such as B cells, produce antibodies that could detect and incite destruction of pathogens that bear similar antigens in case of re-exposure. However, certain pathogens are capable of antigenic variation and therefore would render the antibodies ineffective against them.
Some of the mechanisms employed to enable antigenic variation are gene conversion, site-specific DNA inversions, and hypermutation.
See also:
Dictionary > Antigenic variation
You will also like...
Fruits, Flowers, and Seeds
This tutorial deals with the structure and function of flowers, fruits, and seeds. Also included here are the types of f..
Adaptive Radiation
The diversification of several new species from a recent ancestral source, each adapted to utilize or occupy a vacant ad..
Examples of Natural Selection
Darwin's Finches are an example of natural selection in action. They are an excellent example of the way species' gene p..
Physical Development in Humans
This tutorial elaborates on the physical development of humans, particularly from puberty to adulthood. Read this tutori..
A Balanced Diet – Minerals and Proteins
Proteins and minerals can be derived from various dietary sources. They are essential for the proper growth and developm..
Homeostasis of Organism Water Regulation
Osmoregulation is the regulation of water concentrations in the bloodstream, effectively controlling the amount of water..