Cigarette Smoke Condensate affects Dendritic Cell (DC) Maturation by Modulating DC-Epithelial Cell Cross-talk

Abstract

RationaleCigarette smoke suppresses dendritic cell (DC) function and also affects cytokine expression in epithelial cell (EC) cultures. Since smoke affects these cells simultaneously in vivo, it was reasoned that the smoke effects on DC may be modulated by its effects on ECs. Therefore, the role of cigarette smoke condensate (CSC) induced phenotypic and functional changes in DC and DC-EC cultures were compared.MethodsConfluent, monolayer EC were cultured in the presence or absence of 10 μg/ml (low) or 50 μg/ml (high) CSC for 12 hours and poly I:C stimulated. Monocyte-derived immature dendritic cells (iDC) were then added to the EC culture or cultured alone in the presence or absence of CSC and Poly I:C for 24 hours. CSC-exposed iDC were stained for viability, surface maturation markers and analyzed by flow cytometry. Cytokine levels were examined by a 14-plex bead array and endocytosis was evaluated by FITC-dextran uptake.ResultsCSC exposure in both DC and EC-DC cultures have minimal effects on viability. Both doses of CSC reduce CD80, CD83, CD86 maturation markers, including CD54 (ICAM-1). DC cultures exhibit an increase in endocytosis while the EC-DC cultures show a significant decrease in endocytosis. Analysis of the cytokine profiles shows that the expression of IL1-beta, IL-6, IL-10, IL-12p40 and IL-13 increase in EC-DC cultures as compared to DC alone. When pre-stimulated with poly I:C, CSC enhances expression of IL-10, IL-12p40 and decreases expression of IL-13 in EC-DC co-cultures.ConclusionCSC modulates EC-DC cross-talk by inducing production of cytokines that do not affect DC maturation but affect their function. RationaleCigarette smoke suppresses dendritic cell (DC) function and also affects cytokine expression in epithelial cell (EC) cultures. Since smoke affects these cells simultaneously in vivo, it was reasoned that the smoke effects on DC may be modulated by its effects on ECs. Therefore, the role of cigarette smoke condensate (CSC) induced phenotypic and functional changes in DC and DC-EC cultures were compared. Cigarette smoke suppresses dendritic cell (DC) function and also affects cytokine expression in epithelial cell (EC) cultures. Since smoke affects these cells simultaneously in vivo, it was reasoned that the smoke effects on DC may be modulated by its effects on ECs. Therefore, the role of cigarette smoke condensate (CSC) induced phenotypic and functional changes in DC and DC-EC cultures were compared. MethodsConfluent, monolayer EC were cultured in the presence or absence of 10 μg/ml (low) or 50 μg/ml (high) CSC for 12 hours and poly I:C stimulated. Monocyte-derived immature dendritic cells (iDC) were then added to the EC culture or cultured alone in the presence or absence of CSC and Poly I:C for 24 hours. CSC-exposed iDC were stained for viability, surface maturation markers and analyzed by flow cytometry. Cytokine levels were examined by a 14-plex bead array and endocytosis was evaluated by FITC-dextran uptake. Confluent, monolayer EC were cultured in the presence or absence of 10 μg/ml (low) or 50 μg/ml (high) CSC for 12 hours and poly I:C stimulated. Monocyte-derived immature dendritic cells (iDC) were then added to the EC culture or cultured alone in the presence or absence of CSC and Poly I:C for 24 hours. CSC-exposed iDC were stained for viability, surface maturation markers and analyzed by flow cytometry. Cytokine levels were examined by a 14-plex bead array and endocytosis was evaluated by FITC-dextran uptake. ResultsCSC exposure in both DC and EC-DC cultures have minimal effects on viability. Both doses of CSC reduce CD80, CD83, CD86 maturation markers, including CD54 (ICAM-1). DC cultures exhibit an increase in endocytosis while the EC-DC cultures show a significant decrease in endocytosis. Analysis of the cytokine profiles shows that the expression of IL1-beta, IL-6, IL-10, IL-12p40 and IL-13 increase in EC-DC cultures as compared to DC alone. When pre-stimulated with poly I:C, CSC enhances expression of IL-10, IL-12p40 and decreases expression of IL-13 in EC-DC co-cultures. CSC exposure in both DC and EC-DC cultures have minimal effects on viability. Both doses of CSC reduce CD80, CD83, CD86 maturation markers, including CD54 (ICAM-1). DC cultures exhibit an increase in endocytosis while the EC-DC cultures show a significant decrease in endocytosis. Analysis of the cytokine profiles shows that the expression of IL1-beta, IL-6, IL-10, IL-12p40 and IL-13 increase in EC-DC cultures as compared to DC alone. When pre-stimulated with poly I:C, CSC enhances expression of IL-10, IL-12p40 and decreases expression of IL-13 in EC-DC co-cultures. ConclusionCSC modulates EC-DC cross-talk by inducing production of cytokines that do not affect DC maturation but affect their function. CSC modulates EC-DC cross-talk by inducing production of cytokines that do not affect DC maturation but affect their function.