TLR9 and ischemia: Interestingly, the treatment of germ-free mice with LPS, LTA or CpG (TLR9 agonist) is enough to transiently switch the systemic immune response from anti-inflammatory into a pro-inflammatory response during a model of intestinal ischemia/reperfusion injury and induce protection against pulmonary infection by Klebsiella pneumoniae (85).