title: CD154 plays a central role in regulating dendritic cell activation during infections that induce Th1 or Th2 responses.
abstract: We compared splenic DC activation during infection with either the Th2 response-inducing parasite Schistosoma mansoni or with the Th1 response-inducing parasite Toxoplasma gondii. CD8alpha(+) DC from schistosome-infected mice exhibited a 2- to 3-fold increase in the expression of MHC class II, CD80, and CD40 (but not CD86) compared with DC from uninfected control animals, while CD8alpha(-) DC exhibited a 2- to 3-fold increase in the expression of MHC class II and CD80 and no alteration, compared with DC from uninfected mice, in the expression of CD86 or CD40. Intracellular staining revealed that DC did not produce IL-12 during infection with S. mansoni. In contrast, infection with T. gondii resulted in a more pronounced increase in the expression of activation-associated molecules (MHC class II, CD80, CD86, and CD40) on both CD8alpha(-) and CD8alpha(+) splenic DC and promoted elevated IL-12 production by DC. Analysis of MHC class I and of additional costimulatory molecules (ICOSL, ICAM-1, OX40L, 4-1BBL, and B7-DC) revealed a generally similar pattern, with greater indication of activation in T. gondii-infected mice compared with S. mansoni-infected animals. Strikingly, the activation of DC observed during infection with either parasite was not apparent in DC from infected CD154(-/-) mice, indicating that CD40/CD154 interactions are essential for maintaining DC activation during infection regardless of whether the outcome is a Th1 or a Th2 response. However, the ability of this activation pathway to induce IL-12 production by DC is restrained in S. mansoni-infected, but not T. gondii-infected, mice by Ag-responsive CD11c(-) cells.
authors.affiliation: Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia 19104, USA.
authors.forename: Amy D
authors.initials: AD
authors.lastname: Straw
authors.forename: Andrew S
authors.initials: AS
authors.lastname: MacDonald
authors.forename: Eric Y
authors.initials: EY
authors.lastname: Denkers
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Pearce
mesh_terms: D000818:Animals; D019013:CD40 Antigens / Q000276:immunology / Q000378:metabolism; D023201:CD40 Ligand / Q000502:physiology*; D016827:CD8 Antigens / Q000032:analysis / Q000096:biosynthesis; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D016130:Immunophenotyping; D018664:Interleukin-12 / Q000096:biosynthesis; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012555:Schistosomiasis mansoni / Q000276:immunology* / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D014124:Toxoplasmosis, Animal / Q000276:immunology* / Q000378:metabolism
chemical_list: D019013:CD40 Antigens; D016827:CD8 Antigens; C431698:CD8alpha antigen; D023201:CD40 Ligand; D018664:Interleukin-12