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IL-1R/TLRs play an important role in the inflammatory responses. Their signaling pathway is tightly regulated to keep inflammation under control. The regulation involves both extracellular and intracellular mechanisms. TIR8, also known as SIGIRR (Single Immunoglobulin IL-1R-Related molecule), is an orphan receptor belonging to the IL-1R/TLRs super-family. Recent studies suggest its role in modulating the inflammatory response in the gastrointestinal tract in mice, acting as an IL-1 receptor family antagonist. We identified the sequence and analyzed the expression of TIR8 in a wide panel of organs and tissues in different animals. There was high homology of the cDNA sequence among human, mouse and the domestic species (74-85%). The pattern of expression of this receptor was similar in all the species examined (high levels in kidney and gastrointestinal tract) and similar to the human. These results demonstrate that TIR8 is conserved, in evolutionary terms, both with regard to sequence and pattern of expression, a finding consistent with a key function of this molecule in modulating inflammation in the gastrointestinal tract.

Fetal cells and DNA have been detected in the maternal circulation during and after pregnancy in a few mammalian species. The incidence of similar microchimerism in cattle could have repercussion for the application of modern biotechnologies such as the transfer of transgenic embryos. To determine if feto-maternal leakage can occur in pregnant cows, we have analyzed maternal blood samples for the presence of fetal DNA during gestation and post-partum periods. Y chromosome-specific DNA was detected in up to 73% of blood samples from naturally mated heifers carrying conventional bull calves and a transgene-specific sequence in up to 50% of recipient cows carrying transgenic fetuses. These findings document for the first time that transplacental leakage of fetal DNA into the maternal circulation can occur in cattle despite the epitheliochorial placenta of ruminants, with potential implications for the utilization of recipient cows in the food chain.