In our current report, we have clearly demonstrated that TLR2 and TLR4 are critical to clearance of Brucella infection from the lung, although less prominently than MyD88. This contrasts significantly with the clearance profile for the spleen and liver and may arise as a result of differences in the TLR expression pattern or levels reported for different tissues (Nishimura and Naito, 2005) . It should be noted that based on results of previous studies Frontiers in Cellular and Infection Microbiology www.frontiersin.org September 2012 | Volume 2 | Article 115 | 8 following i.p. inoculation in which only the spleens were examined, it was concluded that Brucella infection was unaffected by the loss of TLR2, however, bacterial load in the lungs and livers were not determined in these studies. (Campos et al., 2004; Weiss et al., 2005; Copin et al., 2007; Macedo et al., 2008) . In agreement with previous studies, the results confirm MyD88 as a critical factor in the control of Brucella infection in the spleen (Campos et al., 2004; Weiss et al., 2005; Barquero-Calvo et al., 2007; Copin et al., 2007; Macedo et al., 2008) . However, caution is warranted in interpretation of the significance of host factors based on the analysis of a single tissue. Recent results in our laboratory indicate that Brucella may be recovered from the lung following i.p. inoculation, indicating a need to consider persistence in this tissue irrespective of the route of infection.