Four to eight month old, male and female C57BL10SnJ mice (wild type, WT) and C57BL10ScN mice homozygous for deletion of TLR4 (dTLR4) were obtained from the Jackson Laboratory, Bar Harbor, Maine. These mice do not express the IL-12Rb2 mutation that was originally described for this strain [35] . Mice of each sex and age were used randomly in each of the various protocols. Mice were housed in a temperature-controlled environment (2262uC; 5565% relative humidity), 12/12 light/dark cycle, and fed standard chow. Experiments were approved by the Institutional Animal Care and Use Committee, Mayo Clinic, Rochester, MN.