title: Trogocytosis of peptide-MHC class II complexes from dendritic cells confers antigen-presenting ability on basophils.
abstract: Th2 immunity plays important roles in both protective and allergic responses. Nevertheless, the nature of antigen-presenting cells responsible for Th2 cell differentiation remains ill-defined compared with the nature of the cells responsible for Th1 and Th17 cell differentiation. Basophils have attracted attention as a producer of Th2-inducing cytokine IL-4, whereas their MHC class II (MHC-II) expression and function as antigen-presenting cells are matters of considerable controversy. Here we revisited the MHC-II expression on basophils and explored its functional relevance in Th2 cell differentiation. Basophils generated in vitro from bone marrow cells in culture with IL-3 plus GM-CSF displayed MHC-II on the cell surface, whereas those generated in culture with IL-3 alone did not. Of note, these MHC-II-expressing basophils showed little or no transcription of the corresponding MHC-II gene. The GM-CSF addition to culture expanded dendritic cells (DCs) other than basophils. Coculture of basophils and DCs revealed that basophils acquired peptide-MHC-II complexes from DCs via cell contact-dependent trogocytosis. The acquired complexes, together with CD86, enabled basophils to stimulate peptide-specific T cells, leading to their proliferation and IL-4 production, indicating that basophils can function as antigen-presenting cells for Th2 cell differentiation. Transfer of MHC-II from DCs to basophils was also detected in draining lymph nodes of mice with atopic dermatitis-like skin inflammation. Thus, the present study defined the mechanism by which basophils display MHC-II on the cell surface and appears to reconcile some discrepancies observed in previous studies.
authors.affiliation: Department of Immune Regulation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Miyake
authors.affiliation: Department of Immune Regulation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Shiozawa
authors.affiliation: Department of Immune Regulation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan.
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Nagao
authors.affiliation: Department of Immune Regulation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Yoshikawa
authors.affiliation: Department of Immune Regulation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Yamanishi
authors.affiliation: Department of Immune Regulation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan karasuyama.mbch@tmd.ac.jp.
authors.forename: Hajime
authors.initials: H
authors.lastname: Karasuyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001491:Basophils / Q000276:immunology*; D002117:Calcitriol / Q000031:analogs & derivatives / Q000633:toxicity; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000494:pharmacology; D003713:Dendritic Cells / Q000276:immunology*; D003877:Dermatitis, Contact / Q000276:immunology / Q000473:pathology; D005802:Genes, MHC Class II / Q000187:drug effects; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D054992:Immunological Synapses / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D018418:Th2 Cells / Q000276:immunology; D053802:Tryptases / Q000235:genetics
chemical_list: D016207:Cytokines; D000949:Histocompatibility Antigens Class II; C474482:I-A(b) antigen, mouse; C024138:I-E-antigen; D010446:Peptide Fragments; C055085:calcipotriene; C512639:Mcpt8 protein, mouse; D053802:Tryptases; D002117:Calcitriol
keywords: MHC class II; basophil; dendritic cell; trogocytosis