BACKGROUND: A unique type of CD11c(pos) dendritic cells (DC) is abundant in inflamed tissue, for example, in chronic inflammatory skin diseases. Due to their remarkable production of tumor necrosis factor (TNF)-α and inducible NO synthase (iNOS), these cells have been referred to as TNF and iNOS-producing DC (Tip-DC). While Tip-DC have been mainly characterized in murine models of infection, functional data about their human counterpart are lacking. OBJECTIVES: We sought to generate human Tip-DC in vitro und thus provide a new model for the investigation of their phenotype and function. METHODS: We generated human Tip-DC from monocytic precursor cells of healthy individuals, atopic and psoriatic patients using human serum. Resting and stimulated cells were analyzed by flow cytometry, real-time PCR, and by ELISA. INOS activity was measured by fluorometric detection of NO. RESULTS: Tip-DC closely resembled their in vivo counterparts by expressing CD11c, CD86, and CD40 while lacking CD1a, CD1c, or CD207/Langerin. Bacterial stimulation of Tip-DC from healthy donors, atopic dermatitis, or psoriasis patients resulted in a similar increase in iNOS activity and TNF-α production. In kinetic experiments, TNF-α, a putative activator of Tip-DC, could not induce NOS2. Upon bacterial stimulation, TNFA, IL6, IL12B, and IL23A mRNA appeared in a first wave, while IL12A and NOS2 mRNA were up-regulated later on but not blocked by anti-TNF-α agents, implying a biphasic pro-inflammatory response. CONCLUSIONS: We developed a new model for the study of human Tip-DC and provide the first evidence of their pro-inflammatory capacity.
BACKGROUND: A unique type of CD11c(pos) dendritic cells (DC) is abundant in inflamed tissue, for example, in chronic inflammatory skin diseases. Due to their remarkable production of tumor necrosis factor (TNF)-α and inducible NO synthase (iNOS), these cells have been referred to as TNF and iNOS-producing DC (Tip-DC). While Tip-DC have been mainly characterized in murine models of infection, functional data about their human counterpart are lacking. OBJECTIVES: We sought to generate human Tip-DC in vitro und thus provide a new model for the investigation of their phenotype and function. METHODS: We generated human Tip-DC from monocytic precursor cells of healthy individuals, atopic and psoriaticpatients using human serum. Resting and stimulated cells were analyzed by flow cytometry, real-time PCR, and by ELISA. INOS activity was measured by fluorometric detection of NO. RESULTS: Tip-DC closely resembled their in vivo counterparts by expressing CD11c, CD86, and CD40 while lacking CD1a, CD1c, or CD207/Langerin. Bacterial stimulation of Tip-DC from healthy donors, atopic dermatitis, or psoriasispatients resulted in a similar increase in iNOS activity and TNF-α production. In kinetic experiments, TNF-α, a putative activator of Tip-DC, could not induce NOS2. Upon bacterial stimulation, TNFA, IL6, IL12B, and IL23A mRNA appeared in a first wave, while IL12A and NOS2 mRNA were up-regulated later on but not blocked by anti-TNF-α agents, implying a biphasic pro-inflammatory response. CONCLUSIONS: We developed a new model for the study of human Tip-DC and provide the first evidence of their pro-inflammatory capacity.
Authors: Julia P Snyder; Soyeon K Gullickson; Roxana Del Rio-Guerra; Andrea Sweezy; Bay Vagher; Tyler C Hogan; Karolyn G Lahue; Julie A Reisz; Angelo D'Alessandro; Dimitry N Krementsov; Eyal Amiel Journal: J Immunol Date: 2021-12-06 Impact factor: 5.426
Authors: Jianghong Zhong; Tatjana Scholz; Anthony C Y Yau; Simon Guerard; Ulrike Hüffmeier; Harald Burkhardt; Rikard Holmdahl Journal: Sci Adv Date: 2018-05-16 Impact factor: 14.136