title: A novel regulatory role of gp49B on dendritic cells in T-cell priming.
abstract: Dendritic cells (DC) play pivotal roles in the induction and regulation of both innate and acquired immunity. DC express several cell-surface immune inhibitory receptors. However, little is known about their potential immunoregulatory functions in the context of T-cell activation. Here we report that murine gp49B, a member of the immunoglobulin superfamily, harboring immunoreceptor tyrosine-based inhibitory motifs, is expressed on DC and downregulates cellular activity to prevent the excessive activation of T cells in vitro and in vivo. Bone marrow-derived DC (BMDC) from newly generated gp49B-deficient (gp49B(-/-)) mice induced enhanced proliferation and IL-2 release of antigen-specific CD4(+) and CD8(+) T cells compared with BMDC from wild-type mice, in a cell-cell contact manner. The enhanced proliferation by gp49B(-/-) BMDC was also observed in allogeneic CD4(+) and CD8(+) T cells. Moreover, the transfer of allogeneic BALB/c splenocytes into C57BL/6 gp49B(-/-) mice induced severe acute graft-versus-host disease with an augmented upregulation of CD86 on CD11c(+) splenic gp49B(-/-) DC, while transfer of C57BL/6 gp49B(-/-) splenocytes into BALB/c mice did not, suggesting the exacerbation of the disease was due, at least in part, to augmented activation of recipient gp49B(-/-) DC. These findings demonstrate a novel regulatory role of gp49B in the function of DC.
authors.affiliation: Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kasai
authors.forename: Masanori
authors.initials: M
authors.lastname: Inui
authors.forename: Kyohei
authors.initials: K
authors.lastname: Nakamura
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kakizaki
authors.forename: Shota
authors.initials: S
authors.lastname: Endo
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamura
authors.forename: Sadayoshi
authors.initials: S
authors.lastname: Ito
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takai
mesh_terms: D000818:Animals; D016207:Cytokines / Q000276:immunology* / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D006086:Graft vs Host Disease / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism
chemical_list: D016207:Cytokines; C489448:Lilrb4 protein, mouse; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic