Antigenic variation

Antigenic variation

Antigenic variation is the process by which an infectious organism alters its surface proteins in order to evade a host immune response. This change in antigenic profile may occur as the pathogen passes through a host population (also called "antigenic diversity") or may take place in the originally infected host. The strategy is particularly important for organisms that target long-lived hosts, repeatedly infect a single host, and are easily transmitted. Pathogens that express these characteristics and undergo antigenic variation have a selective advantage over their more genetically stable counterparts.

Antigenic variation can occur through three broadly defined genetic processes: gene mutation, recombination, and switching. In all cases, antigenic variation results in pathogens that are immunologically distinct from the parental strains.

One possible consequence of antigenic variation is antigenic escape.

References

* Barbour AG, Dai Q, Restrepo BI, Stoenner HG, Frank SA., "Pathogen escape from host immunity by a genome program for antigenic variation", Proc Natl Acad Sci U S A. 2006 Nov 13;
* Barbour AG, Restrepo BI., "Antigenic variation in vector-borne pathogens."Emerg Infect Dis. 2000 Sep-Oct;6(5):449-57. Review.


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