In a study reported in the February 2007 issue of Gastroenterology,
researchers analyzed the effect of ethanol on HCV-specific immune responses in
mice, focusing on dendritic cells (DCs) as a mechanism for reduced CD8 cytotoxic
T-lymphocyte (CTL) activity in response to the HCV NS5 non-structural protein.
Mice were fed an ethanol-containing or normal control diet for 8 weeks.
DCs were then isolated from the spleen and evaluated for endocytosis properties,
cell surface markers, allostimulatory activity, and cytokine production.
Results
•
Long-term ethanol exposure resulted in a reduced number of DCs in the spleen,
but did not alter the cells' endocytosis capacity.
•
The myeloid population
of DC cells was increased, while the lymphoid DC population was reduced.
•
Ethanol reduced expression
of CD40 and CD86 co-stimulatory molecules on resting DCs, which was corrected
following stimulation with lipopolysaccharide or poly I:C.
•
DCs in the ethanol-exposed
mice had impaired allostimulatory activity.
•
Cytokine profiles of
DCs isolated from ethanol-exposed mice demonstrated:
•
Impaired CTL responses
to NS5 were corrected by introducing DCs from the control mice.
Conclusion
In
conclusion, the authors wrote, "Altered DC function is one of the major changes
induced by long-term ethanol consumption, which subsequently impairs the cellular
immune response necessary for viral clearance."
Liver Research
Center, Rhode Island Hospital and Brown Medical School, Providence, RI.
03/30/07
References C
Aloman, S Gehring, P Wintermeyer, and others. Chronic Ethanol Consumption Impairs
Cellular Immune Responses Against HCV NS5 Protein Due to Dendritic Cell Dysfunction.
Gastroenterology 132(2): 698-708. February 2007.
It
is well known that 
