Breeding pairs of TLR2 −/− , TLR4 −/− , and MyD88 −/− mice were obtained from Dr. S. Akira (Osaka University, Osaka, Japan) via Dr. Michael Berton (University of Texas at San Antonio, San Antonio, TX) and colonies maintained by Comparative Medicine Program (CMP) personnel at TAMU. C57BL/6 control mice were purchased from Jackson Laboratory. All mice were housed in BSL-3 suite in the CMP at Texas A&M University. Mice of both sexes between 8 and 12 weeks old were used in the experiments. Euthanasia was performed using carbon dioxide inhalation. All personnel working with animals received training in rodent handling and euthanasia via the CMP. All animal work was performed in compliance with the Public Health Service (PHS) Policy on Humane Care and Use of Laboratory Animals as described by the National Research Council's Institute for Laboratory Animal Research (ILAR) Guide for the Care and Use of Laboratory Animals.