title: Selective serotonin reuptake inhibitors attenuate the antigen presentation from dendritic cells to effector T lymphocytes.
abstract: Fluoxetine, one of the selective serotonin reuptake inhibitors (SSRIs), has been found to possess immune modulation effects, in addition to its antidepressant effects. However, it remains unclear whether SSRIs can suppress the antigen-presenting function of dendritic cells (DCs). Therefore, Fluoxetine was applied to a co-culture of Aggregatibacter actinomycetemcomitans (Aa)-reactive T cells (×Aa-T) isolated from Aa-immunized mice and DCs. This resulted in the suppressed proliferation of ×Aa-T stimulated with Aa-antigen presentation by DCs. Specifically, Fluoxetine increased the extracellular 5-hydroxytryptamine (5-HT) in the ×Aa-T/DC co-culture, whereas exogenously applied 5-HT promoted T-cell proliferation in the ×Aa-T/DC co-culture, indicating that Fluoxetine-mediated suppression of ×Aa-T/DC responses cannot be attributed to extracellular 5-HT. Instead, Fluoxetine remarkably suppressed the expression of costimulatory molecule ICOS-L on DCs. Fluoxetine also promoted a greater proportion of CD86(Low) immature DCs than CD86(High) mature DCs, while maintaining the expression levels of CD80, MHC-class-II and PD-L1. These results suggested that Fluoxetine suppressed the ability of DCs to present bacterial antigens to T cells, and the resulting T-cell proliferation, in a SERT/5-HT-independent manner and that diminished expression of ICOS-L on DCs and increase of CD86(Low) immature DCs caused by Fluoxetine might be partially associated with Fluoxetine-mediated suppression of DC/T-cell responses.
authors.affiliation: Department of Physiological Sciences, Piracicaba Dental School, University of Campinas, SP, Brazil.
authors.forename: Luciana S
authors.initials: LS
authors.lastname: Branco-de-Almeida
authors.forename: Mikihito
authors.initials: M
authors.lastname: Kajiya
authors.forename: Cristina R
authors.initials: CR
authors.lastname: Cardoso
authors.forename: Marcelo J B
authors.initials: MJ
authors.lastname: Silva
authors.forename: Kouji
authors.initials: K
authors.lastname: Ohta
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Rosalen
authors.forename: Gilson C N
authors.initials: GC
authors.lastname: Franco
authors.forename: Xiaozhe
authors.initials: X
authors.lastname: Han
authors.forename: Martin A
authors.initials: MA
authors.lastname: Taubman
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kawai
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects*; D051940:B7-2 Antigen; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D016207:Cytokines / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology*; D003891:Desipramine / Q000494:pharmacology; D005473:Fluoxetine / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012701:Serotonin / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology*
chemical_list: D051940:B7-2 Antigen; D016207:Cytokines; D003891:Desipramine; D005473:Fluoxetine; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors; C497965:Cd86 protein, mouse