title: Trypanosomal immune evasion, chronicity and transmission: an elegant balancing act.
abstract: During their life cycle, trypanosomes must overcome conflicting demands to ensure their survival and transmission. First, they must evade immunity without overwhelming the host. Second, they must generate and maintain transmission stages at sufficient levels to allow passage into their tsetse vector. Finally, they must rapidly commit to onward development when they enter the tsetse fly. On the basis of recent quantification and modelling of Trypanosoma brucei infection dynamics, we propose that the interplay between immune evasion and development achieves both infection chronicity and transmissibility. Moreover, we suggest that a novel form of bistable regulation ensures developmental commitment on entry into the tsetse fly midgut.
authors.affiliation: Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh                 EH9 3JT, United Kingdom.
authors.forename: Paula
authors.initials: P
authors.lastname: MacGregor
authors.forename: Balazs
authors.initials: B
authors.lastname: Szöőr
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Savill
authors.forename: Keith R
authors.initials: KR
authors.lastname: Matthews
mesh_terms: D000818:Animals; D002908:Chronic Disease; D006801:Humans; D057131:Immune Evasion; D008288:Malaria / Q000635:transmission*; D014346:Trypanosoma brucei brucei / Q000276:immunology / Q000472:pathogenicity*; D014370:Tsetse Flies / Q000469:parasitology