Levels of TLR1, TLR2, and TLR9 mRNA increase in response to infection while TLR6 mRNA levels decrease during sublethal infection with S. enterica serovar Typhimurium M525P. TLR1 (A), TLR2 (B), TLR9 (C), and TLR6 (D) mRNA in spleens and livers from C57BL/6 mice were quantified at various times postinfection after intravenous inoculation of 103 CFU of S. enterica serovar Typhimurium M525P. Cycle threshold (Ct) values are expressed subtracted from 40 (the negative endpoint); higher values represent higher levels of mRNA. The mRNA levels were standardized to 18S rRNA levels in spleens and livers from infected and control mice. The data for times at which there is a significant difference between mock-infected and Salmonella infected organs are also expressed as fold changes in mRNA levels compared to the mock-infected control (striped bars), calculated as follows: 2[(40 − Ct for infected mice) − (40 − Ct for control mice)]. Two asterisks indicate that the P value is <0.01, and three asterisks indicate that the P value is <0.001. PBS, phosphate-buffered saline; p.i., postinfection.