Figure 2. Alcohol impairs innate and adaptive immunity.
Acute and chronic alcohol has broad immunoregulatory effects. Cells of the innate immune system (macrophages, monocytes, dendritic cells, NK cells) are modulated by alcohol in their capacity to respond to pathogens. Inflammatory cell responses including production of pro-inflammatory cytokines (IL-1, TNFa) and NF-kB activation are inhibited by acute alcohol exposure while chronic alcohol augments these pro-inflammatory responses. The antigen presenting function of both monocytes and dendritic cells is impaired by both acute and chronic alcohol and this contributes to impaired induction of adaptive immune responses. Both acute and chronic alcohol inhibits T cell functions and IL-12 production and results in alterations in Th1 (IFNg) and Th2 (IL-10) cytokine production. These alcohol-induced abnormalities then collectively contribute to impaired pathogen elimination and reduced adaptive immune responses in the alcohol-exposed host.