IL-10 is a potent anti-inflammatory cytokine important in the resolution of infection. IL-10 helps to moderate excessive inflammation associated with microbial infections and tips the balance of the immune response towards TH2.
However, IL-10 has been shown to be a critical component of many bacterial, viral, and protozoan infection strategies. Duell et al. (below) reviews the strategies used by microbes that utilize IL-10 to avoid immune clearance. Within this review Duell et al. demonstrates that IL-10 can inhibit antimicrobial actions in antigen presenting cells through the downregulation of INFγ (which would restrict tryptophan) and inhibits the fusion of vacuoles with lysozyme which may allow intracellular infections (such as coccidiosis) to persist. IL-10 regulation in the early and mid-stage of infection are important to understand and it would seem that this regulation determines whether an infection persists or is cleared.IL-10-and-infection-review