Figure 1. A model on the direct roles of TLR stimulation on Treg function.

This model is based on the following conditions and predictions (stimulatory, inhibitory): (i) functional outcome is dictated by the nature of PAMPs; (ii) acute sepsis is more often associated with bacterial and fungal but not viral infection; (iii) viral nucleic acids-sensing TLRs block Treg to amplify adaptive immunity, whereas bacterium/fungus-sensing TLRs enhance it to curtail acute sepsis.