TLR2 and Klebsiella Infections: A small number of studies have investigated the contribution of NLR signalling to defence against Klebsiella. NLRP3−/− mice demonstrate an increase in mortality following Klebsiella infection albeit the protective role of NLRP3 is not as important as those of TLR4 and TLR2, and any of the TLR adaptors (Willingham et al.2009).