Definitions for antigenic variation
anti·genic vari·a·tion

WikidataRate this definition:0.0 / 0 votes

1. Antigenic variation

   Antigenic variation refers to the mechanism by which an infectious organism such as a protozoan, bacterium or virus alters its surface proteins in order to evade a host immune response. Immune evasion is particularly important for organisms that target long-lived hosts, repeatedly infect a single host and are easily transmittable. Antigenic variation not only enables immune evasion by the pathogen, but also allows the microbes to cause re-infection, as their antigens are no longer recognized by the host's immune system. When an organism is exposed to a particular antigen an immune response is stimulated and antibodies are generated to target that specific antigen. The immune system will then "remember" that particular antigen, and defenses aimed at that antigen become part of the immune system’s acquired immune response. If the same pathogen tries to re-infect the same host the antibodies will act rapidly to target the pathogen for destruction. However, if the pathogen can alter its surface antigens, it can evade the host's acquired immune system. This will allow the pathogen to re-infect the host while the immune system generates new antibodies to target the newly identified antigen. Antigenic variation can occur by altering a variety of surface molecules including proteins and carbohydrates. There are many molecular mechanisms behind antigenic variation, including gene conversion, site-specific DNA inversions, hypermutation, as well as recombination of sequence cassettes. In all cases, antigenic variation and phase variation, a type of antigenic variation, result in a heterogenic phenotype of a clonal population. Individual cells either express the phase-variable protein or express one of multiple antigenic forms of the protein. This form of regulation has been identified mainly, but not exclusively, for a wide variety of surface structures in pathogens and is implicated as a virulence strategy.

U.S. National Library of MedicineRate this definition:0.0 / 0 votes

1. Antigenic Variation

   Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)

How to pronounce antigenic variation?

1. Alex

   US English

   David

   US English

   Mark

   US English

   Daniel

   British

   Libby

   British

   Mia

   British

   Karen

   Australian

   Hayley

   Australian

   Natasha

   Australian

   Veena

   Indian

   Priya

   Indian

   Neerja

   Indian

   Zira

   US English

   Oliver

   British

   Wendy

   British

   Fred

   US English

   Tessa

   South African

How to say antigenic variation in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of antigenic variation in Chaldean Numerology is: 2

2. Pythagorean Numerology

   The numerical value of antigenic variation in Pythagorean Numerology is: 2

Examples of antigenic variation in a Sentence

1. Anthony Fauci:

   What we now know from this study, namely the JJ and the Novavax study, that antigenic variation, i.e. mutations that lead to different lineage, do have clinical consequences because as you can see, even though the long-range effect in the sense of severe disease is still handled reasonably well by the vaccines, this is a wakeup call to all of us that we will be dealing, as the virus uses its devices to evade pressure, particularly immunological pressure, that we will continue to see the evolution of mutants.

References

1. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=antigenic variation