title: Induction of cytotoxic T lymphocyte responses by cholera toxin-treated bone marrow-derived dendritic cells.
abstract: Cholera toxin (CT), a powerful mucosal adjuvant, is a potent inducer of Th2-type responses via activation of co-stimulatory molecules for the induction of IgA antibody responses. Less appreciated is the ability of CT to induce and regulate cytotoxic T lymphocyte (CTL) responses. In order to help for clarifying mechanisms underlying the CTL-inducing ability of CT, we have examined the effects of CT on dendritic cells (DCs) that could lead to the induction of cytotoxic CD8(+) T cells. When bone marrow-derived DCs (BM-DCs) were cultured with CT in vitro, B7-1 but not B7-2 molecules were significantly enhanced and allogenic CTL responses were induced. Also, increased numbers of IFN-gamma-secreting CD8(+) T cells were elicited when CT-treated BM-DCs were co-cultured with allogenic CD8(+) CTLs. Antibody blockade of B7-1 on CT-treated BM-DCs suppressed allogenic CTL responses, further indicating the importance of CT-induced B7-1 molecules on DCs for the acquisition of cytolytic function by CTL precursors. CD40 signaling was proven not necessary for the CT-induced CTL response since CT-treated CD40(-/-) BM-DCs developed CTL responses equivalent to those detected in CT-treated BM-DCs derived from normal mice. Our results suggest that CT-treated DCs are effective inducers of CD8(+) CTL, and this induction is mediated through CT's ability to enhance B7-1 expression on DCs.
authors.affiliation: Department of Mucosal Immunology, Research Institute for Microbial Diseases, Osaka University, 565-0871, Osaka, Japan.
authors.forename: Myoung Ho
authors.initials: MH
authors.lastname: Jang
authors.forename: Mi Na
authors.initials: MN
authors.lastname: Kweon
authors.forename: Takachika
authors.initials: T
authors.lastname: Hiroi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyono
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D001854:Bone Marrow Cells / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology*; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D002772:Cholera Toxin