Trypanosome antigenic variation
WebAntigenic variation belongs to the general survival strategy of enhanced phenotypic variation, where a subset of 'contingency' genes of viruses, bacteria and parasites … WebAfrican trypanosomes evade the mammalian host immune response by antigenic variation, the continual switching of their variant surface ... In the metacyclic stage, a specific subset (<28; 1 to 2%) of VSG genes, located at the telomeres of the largest trypanosome chromosomes, are activated by a system very different from that used for ...
Trypanosome antigenic variation
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WebJun 5, 1978 · Abstract. The several species of African trypanosomes pathogenic to man and domestic livestock may evade the immune response through a process of antigenic … WebFeb 13, 2012 · The antigenic variation phenotype is observed in all African trypanosomes, and it is assumed that this reflects a common physiological model, which has been defined in T. brucei.The aim of this study is to identify the evolutionary processes that have created contemporary VSG diversity and reveal any significant differences in how trypanosome …
WebAug 4, 2024 · - My Ph.D. thesis was to identify and evaluate the role of a telomere protein in antigenic variation in protozoan parasite T. brucei. ... has been identified in multiple organisms including Trypanosoma brucei, a protozoan parasite that causes human African trypanosomiasis. T. brucei regularly switches its major surface antigen ... WebJul 29, 2008 · The T. brucei genome contains >1,000 VSG genes [ 4 ], dwarfing the number of variant antigen genes found in other organisms. For instance, antigenic variation in …
WebMar 1, 2004 · Antigenic variation is central to the success of African trypanosomes and other eukaryotic, bacterial and viral pathogens. Our understanding of the control and execution of this immune evasion strategy in trypanosomes is incomplete, despite the molecular basis of antigenic variation being first described over 20 years ago. Recent … WebApr 6, 2009 · Rates at which Trypanosoma brucei rhodesiense trypanosomes switch from expression of one variable antigen type (VAT) to that of another have been determined in cloned populations that have been recently tsetse-fly transmitted. Switching rates have been determined between several, specific pairs of VATs in each population. High rates of …
WebOct 7, 2024 · Antigenic variation has evolved remarkable mechanistic complexity in Trypanosoma brucei, with switching of the VSG coat executed by either transcriptional or recombination reactions. In the former, a single T. brucei cell selectively transcribes one telomeric VSG transcription site, termed the expression site (ES), from a pool of around 15.
WebThe antigenic repertoire of a trypanosome clone or species is so far undetermined and the genetic basis of antigenic variation is unexplored. Structural studies indicate that the … binder post screws brassWebTrypanosoma brucei has developed the most elaborate capacity for antigenic variation. Trypanosomes branched early during eukaryotic evolution. They are characterized by many aberrations, ranging from the unusual compartmentation of metabolic pathways to the heresy of RNA editing. cysticercosis case definitionWebNational Center for Biotechnology Information binder pipe anchorWebJul 1, 2013 · Mosaic VSGs and the Scale of Trypanosoma brucei Antigenic Variation. James P. J. Hall, Huanhuan Wang, J. Barry. Published 1 July 2013. Biology. PLoS Pathogens. A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic … cysticercosis antibody iggWebMay 8, 2007 · Nevertheless, trypanosome antigenic variation differs from that of other pathogens in its likely scale, the repertoire consisting of up to 2,000 VSG genes, the majority of which are pseudogenes. In contrast, the silent MSP2 archive of the bacterium Anaplasma marginale comprises just five pseudogenes ( 6 ), whereas the P. falciparum var archive … cysticercosis csfWebOct 10, 2024 · The protozoan parasite Trypanosoma brucei, a causative agent of human and animal trypanosomiasis, lives extracellularly within its host and evades host immunity through antigenic variation of its ... cysticercosis cdphWebA number of mechanisms have been described by which African trypanosomes undergo the genetic switches that differentially activate their variant surface glycoprotein genes (VSGs) and bring about antigenic variation. These mechanisms have been observed mainly in trypanosome lines adapted, by rapid syringe passaging, to laboratory conditions. cysticercosis blood test