"They hypothesised that these general TLR families are continually present due to the inability of microbes to easily mutate or change the components they recognise."
Or that the parasites have co-evolved to raise a modest immune response, so that the host will survive the infection long enough to pass it along.
Taking that line of thought even further, it would be interesting to know if any commensal organisms had inflammation receptors to avoid accidentally invading the host.
Do you think toll like receptors are subject to contrained diffusional motion within the cell membrane? That is, do you think the motion of TLRs are hindered significantly by interactions with the cellular cytoskeleton?
Daniel: It is believed that commensal bacteria do have a role in immunoregulation. For example, lactobaccilli in yoghurt have been implicated in reducing inflammation that occurs in several intestinal disorders (like Crohn's disease).
Vavoom: It's possible as they need to interact with a wide variety of molecules including one another. Due to the complexity of their signalling domains it wouldn't surprise me if this was the case.
Commenting by HaloScan
