title: Adjuvants determine the contribution of basophils to antigen sensitization in vivo.
abstract: OBJECTIVE
  Basophils expressing FcɛRIα, the alpha chain of the total IgE high affinity receptor, appear to play a role in antigen (Ag) sensitization, although dendritic cells (DCs) are the principal Ag-presenting cells (APCs). To investigate whether these two types of APCs are involved differentially in Ag-sensitization when distinct types of adjuvants are utilized.
  
  
  METHODS
  To investigate whether basophils and DCs serve as APCs in vitro, whole splenocytes, FcɛRIα(+) basophil-depleted splenocytes, and CD11c(+) DC-depleted splenocytes from naïve DO11.10 mice were stimulated in vitro with ovalbumin (OVA) or OVA peptide 323-339 to evaluate Ag-induced proliferation. To investigate whether basophils function as APCs in vivo, BALB/c mice were actively immunized with ragweed (RW) emulsified in alum or Complete Freund's Adjuvant (CFA) followed by an RW challenge in eye drops. An anti-FcɛRIα antibody (Ab) or a control Ab was injected intraperitoneally during the sensitization phase. Twenty-four hours after the RW challenge, conjunctivas and spleens were harvested for histological analysis to evaluate conjunctival eosinophilia and cytokine production, respectively.
  
  
  RESULTS
  Depletion of basophils or DCs from naïve DO11.10 splenocytes significantly suppressed proliferative responses to either OVA or OVA peptide. Treatment with the anti-FcɛRIα Ab suppressed the conjunctival eosinophilia when alum, but not CFA, was utilized as the adjuvant. Similarly, the anti-FcɛRIα Ab inhibited cytokine production by splenocytes when alum was used as the adjuvant.
  
  
  CONCLUSIONS
  Adjuvants determine which APCs are utilized in Ag-sensitization.
authors.affiliation: Department of Ophthalmology, Kochi Medical School, Kohasu, Oko-cho, Nankoku-City 783-8505, Japan.
authors.forename: Waka
authors.initials: W
authors.lastname: Ishida
authors.forename: Ken
authors.initials: K
authors.lastname: Fukuda
authors.forename: Tamaki
authors.initials: T
authors.lastname: Sumi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ebihara
authors.forename: Mina
authors.initials: M
authors.lastname: Kajisako
authors.forename: Hironori
authors.initials: H
authors.lastname: Matsuda
authors.forename: Hideo
authors.initials: H
authors.lastname: Yagita
authors.forename: Atsuki
authors.initials: A
authors.lastname: Fukushima
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D001491:Basophils / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D005620:Freund's Adjuvant / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D000276:Adjuvants, Immunologic; D000941:Antigens; D005620:Freund's Adjuvant