antigenic variation


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antigenic variation

successive changes in the surface ANTIGENS of certain MICROORGANISMS, resulting in a range of antigenically different forms. This can help a PATHOGEN, such as influenza virus, to avoid the host's immune defence system. See IMMUNITY.
References in periodicals archive ?
Mechanisms and molecular pathways underlying antigenic variation of Borreliahermsii variable major lipoprotein (Vmp) and B.
Molecular basis of antigenic variation between the glycoproteins C of respiratory bovine herpesvirus 1 (BHV-1) and neurovirulent BHV-5.
These multigene families are responsible for the antigenic variation of the parasite in natural infections which enables it to escape the host immune response for its survival resulting in prolonged chronic infections.
McCulloch, "Molecular mechanisms underlying the control of antigenic variation in African trypanosomes," Current Opinion in Microbiology, vol.
Focusing on five of the six genera of Rickettsiales (excluding Wolbachia), they discuss the human disease manifestations, the evolution of treatment for infections, challenges for treatment and management, and treatment failures or persistent complaints; epidemiology and public health in the US, as well as the global impact; phylogeny and comparative genomics; the cell biology involved in host invasion; stages of intracellular infection; physiology and metabolism; innate immune response and inflammation in pathogenesis and protection; adaptive immune responses to infection and opportunities for vaccine development; persistence and antigenic variation; transmission; and improving genetic systems.
3) Studies on the antigenic variation of influenza viruses have indicated that they have been continuing to undergo evolutionary changes.
Influenza outbreaks are recorded virtually every year, but the most extensive and severe cases are caused by influenza A viruses, because of periodic antigenic variation. Minor variations are called antigenic drifts and cause epidemics on average, each year.
No vaccine is currently available due largely to the ability of the pathogen to undergo antigenic variation. The work to be presented represents basic research designed to identify potential drug therapy targets for African trypanosomiasis.
The chapters discuss genetic recombination in the tritrypanosomes, genome architecture, atypical chromosome types in trypanosome genomes, gene transcription and post- transcriptional regulation, intracellular transport systems, trypanosome specialized surface molecules, and the process of antigenic variation. Distributed in the US by Taylor & Francis.
Antigenic variation of varicella zoster virus Fc receptor gE: loss of a major B cell epitope in the ectodomain.
The process by which an influenza virus mutates to evade immune systems is called antigenic variation. Every few years, there is an antigenic drift, which causes influenza epidemics.
TABLE 1 Hemagglutination-inhibition titers of influenza B viruses [*] -- United States and worldwide, May-September 25, 2001 Antisera B/Sichuan/ B/Victoria/ B/Hong Kong/ Viral antigen 379/99 504/2000 6/2001 B/Yamagata/16/88 group viruses B/Sichuan/379/99 320 2560 20 B/Victoria/504/2000 320 2560 10 B/Victoria/2/87 group viruses B/Hong Kong/6/2001 [less than]10 20 1280 B/Hong Kong/22/2001 [less than]10 10 640 B/Hong Kong/ Viral antigen 22/2001 B/Yamagata/16/88 group viruses B/Sichuan/379/99 10 B/Victoria/504/2000 [less than]10 B/Victoria/2/87 group viruses B/Hong Kong/6/2001 640 B/Hong Kong/22/2001 640 (*)A fourfold difference in hemagglutination-inhibition titer betwen two viruses usually indicates antigenic variation between viruses.