title: Schistosoma mansoni Larvae Do Not Expand or Activate Foxp3+ Regulatory T Cells during Their Migratory Phase.
abstract: Foxp3(+) regulatory T (Treg) cells play a key role in suppression of immune responses during parasitic helminth infection, both by controlling damaging immunopathology and by inhibiting protective immunity. During the patent phase of Schistosoma mansoni infection, Foxp3(+) Treg cells are activated and suppress egg-elicited Th2 responses, but little is known of their induction and role during the early prepatent larval stage of infection. We quantified Foxp3(+) Treg cell responses during the first 3 weeks of murine S. mansoni infection in C57BL/6 mice, a time when larval parasites migrate from the skin and transit the lungs en route to the hepatic and mesenteric vasculature. In contrast to other helminth infections, S. mansoni did not elicit a Foxp3(+) Treg cell response during this early phase of infection. We found that the numbers and proportions of Foxp3(+) Treg cells remained unchanged in the lungs, draining lymph nodes, and spleens of infected mice. There was no increase in the activation status of Foxp3(+) Treg cells upon infection as assessed by their expression of CD25, Foxp3, and Helios. Furthermore, infection failed to induce Foxp3(+) Treg cells to produce the suppressive cytokine interleukin 10 (IL-10). Instead, only CD4(+) Foxp3(-) IL-4(+) Th2 cells showed increased IL-10 production upon infection. These data indicate that Foxp3(+) Treg cells do not play a prominent role in regulating immunity to S. mansoni larvae and that the character of the initial immune response invoked by S. mansoni parasites contrasts with the responses to other parasitic helminth infections that promote rapid Foxp3(+) Treg cell responses.
authors.affiliation: Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Redpath
authors.affiliation: Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Nienke
authors.initials: N
authors.lastname: van der Werf
authors.affiliation: Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: MacDonald
authors.affiliation: Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Rick M
authors.initials: RM
authors.lastname: Maizels
authors.affiliation: Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom Matthew.Taylor@ed.ac.uk.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Taylor
mesh_terms: D000818:Animals; D002465:Cell Movement; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics / Q000276:immunology; D015847:Interleukin-4 / Q000235:genetics / Q000276:immunology; D007814:Larva / Q000276:immunology / Q000502:physiology; D008168:Lung / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D012550:Schistosoma mansoni / Q000276:immunology* / Q000502:physiology; D012555:Schistosomiasis mansoni / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D013154:Spleen / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000469:parasitology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D016753:Interleukin-10; D015847:Interleukin-4