title: A constitutively active aryl hydrocarbon receptor causes loss of peritoneal B1 cells.
abstract: The dioxin/aryl hydrocarbon (Ah) receptor functions as a ligand-activated transcription factor that mediates toxicity of dioxins and related environmental pollutants. We have developed a transgenic mouse model that expresses a constitutively active Ah receptor. The immune system is one of the most sensitive target organs for dioxin toxicity and we have therefore investigated alterations of different lymphocyte populations in these mice. The population of mature bone-marrow derived B cells was enlarged, consistent with previous findings in dioxin exposed mice. In contrast, the peritoneal population of CD5-expressing B cells (B1 cells) was significantly diminished. This is the first study that demonstrates the effect of an activated Ah receptor on B1 cells. Since these cells are important mediators of innate immunity against pathogens such as Influenza virus, these results may explain the decreased resistance against infections that has been documented after dioxin exposure.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. patrik.andersson@imm.ki.se
authors.forename: Patrik
authors.initials: P
authors.lastname: Andersson
authors.forename: Anna
authors.initials: A
authors.lastname: Ridderstad
authors.forename: Jacqueline
authors.initials: J
authors.lastname: McGuire
authors.forename: Sven
authors.initials: S
authors.lastname: Pettersson
authors.forename: Lorenz
authors.initials: L
authors.lastname: Poellinger
authors.forename: Annika
authors.initials: A
authors.lastname: Hanberg
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000502:physiology*
chemical_list: D018336:Receptors, Aryl Hydrocarbon; D019363:Cytochrome P-450 CYP1A1