Medical professionals have known for years that alcohol consumption and alcohol use disorders – the disease of alcoholism for example – impair a drinker's immune system. A new University of Iowa study pinpoints a specific influenza-fighting T cell as being “exquisitely sensitive to alcohol.” Results were published Aug. 26 online in an “Early View”of the journal Alcoholism: Clinical & Experimental Research.
Previous research had demonstrated an increase in the severity of flu virus infections was due, in part, to a failure to mount a robust T cell response. T cells find and kill infected cells. The new rodent study further examines chronic drinking's damage to CD8 T cells, finding that some functions of CD8 T cells become limited or reduced. “It is well known that chronic alcohol consumption compromises the human immune system," explained lead researcher Kevin Legge in a news release. “Alcohol attacks the CD8 T cell immune response on two separate levels: limiting the number of cells that can fight the infection, and limiting the ability of the remaining cells to fight."
University of California Riverside biomedical sciences associate professor, Ilhem Messaoudi, commented on the finding: "It has also been known since the 1800's that alcohol use disorders are associated with increased susceptibility to lung infection – both viral and bacterial – including community acquired pneumonia, tuberculosis, acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD). Understanding the mechanisms underlying the increased susceptibility to lung infection and injury in individuals with alcohol use disorder is extremely important."
The Iowa researchers spiked the drinking water of mice with alcohol for eight or 12 weeks. Mice were infected with the flu and the research team charted the activation of the CD8 T cells in both the lung-draining lymph nodes and lungs.
"T cells utilize multiple tools – called effector functions – to limit and control pathogens," said Legge. “We show that alcohol may have distinct effects on the effector ability of CD8 T cells, limiting or reducing some functions while leaving other effector functions intact. It is known that triggering of each specific effector pathway requires precise signals. Therefore, further mapping of which effector functions are altered, coupled with examination of pertinent molecules, could yield promising drug targets for reversal of the effects of alcohol on this important adaptive immune cell population."
For instance, new vaccines, more efficient at eliciting CD8 T cell responses, could be developed specifically for drinkers, especially those with the disease of alcoholism.