Volume 132, Issue 2, Pages 698-708 (February 2007) Chronic Ethanol Consumption Impairs Cellular Immune Responses Against HCV NS5 Protein Due to Dendritic Cell Dysfunction  Costica Aloman, Stephan Gehring, Philip Wintermeyer, Noriyoshi Kuzushita, Jack R. Wands  Gastroenterology  Volume 132, Issue 2, Pages 698-708 (February 2007) DOI: 10.1053/j.gastro.2006.11.016 Copyright © 2007 AGA Institute Terms and Conditions

Figure 1 The effect of long-term ethanol feeding on splenic weight, number of cells, and number of DCs. (A) There were significant differences compared with the isocaloric pair-fed controls in the ethanol-fed group. *P < .01. (B) The measurement of the endocytic capacity of DCs isolated from the spleens of ethanol-fed and isocaloric pair-fed control mice. There was a statistically significant decrease in FITC-dextran phagocytosis by DCs derived from ethanol-fed mice at 20 minutes. However, this difference was not sustained. There were 5 animals in each group for both A and B. *P < .05. Gastroenterology 2007 132, 698-708DOI: (10.1053/j.gastro.2006.11.016) Copyright © 2007 AGA Institute Terms and Conditions

Figure 2 A characterization of DC populations derived from the spleens of ethanol and isocaloric pair-fed control animals. (A) Cells were analyzed by 2-color flow cytometry. There was an increase in the CD11c+, CD11b+, myeloid DC population in the ethanol-fed mice. There was a corresponding decrease in the lymphocytoid population as shown in the right panels. (B) Two-color flow cytometry demonstrating no change in the expression of MHC class I and class II antigens on DCs derived from control and ethanol-fed mice. (C) Flow cytometry analysis of DCs expressing CD40, CD80, and CD86 costimulatory molecules before maturation. The majority of the DCs are immature, and there was a reduction in CD40 and CD86 antigen expression in DCs derived from ethanol-fed mice. No difference was observed with respect to CD80 expression. Experiments were repeated 3 times with similar results. Gastroenterology 2007 132, 698-708DOI: (10.1053/j.gastro.2006.11.016) Copyright © 2007 AGA Institute Terms and Conditions

Figure 3 Flow cytometry analysis of DCs expressing (A) CD40, (B) CD80, and (C) CD86 costimulatory molecules after 24 hours of maturation with LPS. No difference was observed with respect to expression of all 3 cell surface markers when comparing both groups. Experiments were repeated 3 times with similar results. Gastroenterology 2007 132, 698-708DOI: (10.1053/j.gastro.2006.11.016) Copyright © 2007 AGA Institute Terms and Conditions

Figure 4 Allostimulatory activity of splenic DCs derived from Balb/c mice was analyzed before and after maturation induced by LPS. At baseline, there was no difference observed between DCs isolated from both groups. After LPS stimulation, a significant difference (P < .01) in 3H-thymidine incorporation between DCs isolated in ethanol-fed mice compared with the control group was noted, indicating a reduced allostimulatory capacity produced by long-term ethanol feeding. The data are representative of 3 separate experiments. Gastroenterology 2007 132, 698-708DOI: (10.1053/j.gastro.2006.11.016) Copyright © 2007 AGA Institute Terms and Conditions

Figure 5 Comparison of cytokine profiles between DCs isolated from ethanol-fed as compared with isocaloric pair-fed controls following poly I:C and LPS stimulation. (A) There was an increase in IL-1β secretion from DCs stimulated with both poly I:C and LPS and in DCs isolated from ethanol-fed mice. *P < .05. (B) IL-6 secretion by DCs isolated from ethanol as compared with control-fed mice. There was enhanced secretion of IL-6 following poly I:C and LPS stimulation. *P < .001. (C) There was a striking increase in TNF-α secretion in controls as compared with ethanol-fed mice following LPS stimulation as well as IFN-γ in both poly I:C– and LPS-stimulated cells. *P < .01. (D) Pattern of IL-12 and IL-10 secretion in DCs. (E and F) There was reduced secretion of IL-12 and enhanced secretion of IL-10 in DCs isolated from ethanol-fed mice under LPS stimulation. *P < .001. There were 5 animals in the ethanol-fed and pair-fed control groups. Gastroenterology 2007 132, 698-708DOI: (10.1053/j.gastro.2006.11.016) Copyright © 2007 AGA Institute Terms and Conditions

Figure 6 Impaired CTL responses are corrected by syngeneic transfer of DCs derived from control animals but not from ethanol-fed mice. CTL assay at various lymphocyte to target cell ratios from 8 different groups fed either ethanol or an isocaloric pair-fed control diet and then immunized with empty plasmid DNA (pAp031) or an expression plasmid containing NS5 (pAp031-NS5) with or without DC transfer. Note that long-term ethanol feeding completely suppresses CTL activity against NS5 to levels seen following immunization with an empty plasmid. The syngeneic transfer of control DCs at the time of DNA-based immunization using the NS5-expressing plasmid completely corrects the defect in CTL activity in ethanol-fed animals. Also note that augmentation of DCs generated in mice fed ethanol does not increase CTL activity when isolated from ethanol-fed animals, indicating that the low level of CTL activity is not due to a reduced number of DCs. DCs isolated from spleens of ethanol-fed mice induce tolerance to generation of CTL activity against NS5 in animals receiving an isocaloric pair-fed control diet with a presumably normal T-cell network. Gastroenterology 2007 132, 698-708DOI: (10.1053/j.gastro.2006.11.016) Copyright © 2007 AGA Institute Terms and Conditions