Evolution of Antigenic Variation
نویسنده
چکیده
processes that shape genetic variability and evolutionary change.The causes of variability and change provide the basis for understanding why simple vaccines work well against some viruses, whereas complex vaccine strategies achieve only limited success against other viruses. The battle between host and parasite often comes down to the rates at which attacker and defender molecules bind or evade each other. The biochemical details of binding and recognition set the rules of engagement that shape the pace, scale, and pattern of diversity and the nature of evolutionary change [45]. The first section of this chapter lists the different ways in which parasites can gain by varying their antigenic molecules. The parasites may, for example, extend their time of infection within a particular host by changing their antigenic molecules to evade the specific recognition built up by the host immune system. Or the parasites may vary to attack hosts that had been exposed previously and had built up specific recognition against prior antigenic molecules. The second section focuses on the nature of binding and recognition between host and parasite molecules. I summarize the different ways in which parasites generate new variants in order to escape molecular recognition. The third section builds up the individual molecular interactions into the dynamics of a single infection within a host. The parasites spread in the host, triggering immune attack against dominant antigens.The battle within the host develops through changes in population numbers – the numbers of parasites with particular antigens and the numbers of immune cells that specifically bind to particular antigens. The fourth and fifth sections discuss how the successes and failures of different parasite antigens within each host determine the rise and fall of parasite variants over space and time. The distribution of parasite variants sets the immune memory profiles of different hosts, which in turn
منابع مشابه
Antigenic Variation of the Haemagglutinin Gene of the Influenza A (H1N1) pdm09 Virus Circulating in Shiraz, February-April 2013
Background: A new pandemic influenza A (H1N1) emerged in April 2009, causing considerable morbidity and mortality. Since mutations in the haemagglutinin (HA) may influence the antigenicity and pathogenicity of the virus, continued epidemiological and molecular characterization for the effective control of pandemic flu and developing of more appropriate vaccine is crucial. Objective: To monitor ...
متن کاملAntigenic variation between rabies virus strains and its relevance in vaccine production and potency testing
متن کامل
Mini-review: Strategies for Variation and Evolution of Bacterial Antigens
Across the eubacteria, antigenic variation has emerged as a strategy to evade host immunity. However, phenotypic variation in some of these antigens also allows the bacteria to exploit variable host niches as well. The specific mechanisms are not shared-derived characters although there is considerable convergent evolution and numerous commonalities reflecting considerations of natural selectio...
متن کاملVirus dynamics: the effect of target cell limitation and immune responses on virus evolution.
Earlier models of virus evolution during single infections do not include target cell limitation. Here we extend the basic mathematical framework of these theories and study the effect of target cell limitation on the evolution of antigenic variation, increasing replication rates and increasing virus load. We find that target cell limitation provides a selection pressure against antigenic diver...
متن کاملPotentially conflicting selective forces that shape the vls antigenic variation system in Borrelia burgdorferi.
Changing environmental conditions present an evolutionary challenge for all organisms. The environment of microbial pathogens, including the adaptive immune responses of the infected host, changes rapidly and is lethal to the pathogen lineages that cannot quickly adapt. The dynamic immune environment creates strong selective pressures favoring microbial pathogen lineages with antigenic variatio...
متن کاملAntigenic variation in vector-borne pathogens.
Several pathogens of humans and domestic animals depend on hematophagous arthropods to transmit them from one vertebrate reservoir host to another and maintain them in an environment. These pathogens use antigenic variation to prolong their circulation in the blood and thus increase the likelihood of transmission. By convergent evolution, bacterial and protozoal vector-borne pathogens have acqu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007