Up-regulated TLR2 and TLR4 expressions in liver and spleen during acute murine T. gondii infection

Toll-like receptors (TLRs) play a central role in the pathogen clearance and pathological processes. The liver is an important innate immune organ, in which Kupffer cells and hepatocytes are important innate immune cells. However, the role of TLR2 and TLR4 in the liver caused by Toxoplasma gondii infection remains less clear. In this study, mice were infected with T. gondii RH strain and the grades of liver and spleen injuries were histopathologically evaluated. TLR2+ and TLR4+ cells in the livers and spleens were detected by immunohistochemistry, and their messenger RNA (mRNA) expressions were detected using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). The pathological severities in the livers and spleens were increased with time in T. gondii-infected mice. Compared with uninfected controls, obvious TLR2+ and TLR4+ cells were observed in the livers and spleens infected with T. gondii at 8 days post-infection, accompanied with significantly over-expressed mRNA levels of TLR2 and TLR4 in the livers and spleens after infection. Our data indicated that increased levels of TLR2 and TLR4 in the liver and spleen may play an important role during acute T. gondii infection.