A new research has revealed that alcohol changes the anti-viral and inflammatory functions of monocytes and that prolonged alcohol consumption has a double negative effect of reducing the anti-viral effect of Type 1 interferon (IFN) while increasing inflammation through the pro-inflammatory cytokine TNFa.
Researchers from the University of Massachusetts Medical School led by Prof Gyongyi Szabo looked at the effect of alcohol on monocytes collected from the blood of healthy volunteers and focussed specifically on two disease related pathways - Toll-like receptor 8 - TLR8 stimulated by single strand RNA viral attack and TLR4 involved in recognising bacteria.
The results of the study showed that activation of these pathways resulted in an increase in the levels of the anti-viral cytokine IFN, which was reduced by treatment with alcohol equivalent to four or five drinks a day for seven days.
The study also found that stimulation of these pathways resulted in an increase in the levels of the pro-inflammatory cytokine TNFa.
A single treatment with alcohol decreased the amount of TNFa, whereas prolonged treatment increased levels of inflammation.
"Alcohol has a profound effect of inhibiting IFN production in monocytes regardless of whether the danger signal is intracellular (TLR8) or surface-derived (TLR4). Such a reduction would impair the body's ability to fight off infection," Prof Szabo said
"Additionally, the fact that Type I IFN production is depressed despite increased levels of the pro-inflammatory cytokine, TNFa, due to chronic alcohol exposure suggests that prolonged alcohol must change the immune balance of monocyte activation and impair host response to single-stranded virus infection like hepatitis C," he added.
The findings of the research have been published in BioMed Central's open access journal BMC Immunology.