Sensory neurons with MHC-like peptide binding properties: disease consequences

Patricia R. Slev1, Adam C. Nelson2 and Wayne K Potts2, E-mail The Corresponding Author
1Department of Pathology, University of Utah, 30 N. 1900 E., Salt Lake, Utah 84132, USA
2Department of Biology, University of Utah, 257 S. 1400 E., Salt Lake, Utah 84112, USA

Available online 1 August 2006.

The recent discovery of specialized sensory neurons that bind peptides in an MHC-like fashion has revealed the long-sought odorants used to recognize the MHC genotype and phenotype of other individuals. The odorants are the same MHC peptides used during immune recognition, which provides the molecular logic linking selection acting on MHC-mediated behaviors with selection acting on immune recognition; both processes influence the evolving peptide binding properties of MHC molecules. The primary function of these chemosensory mechanisms for detecting MHC-mediated odors appears to be mating preferences (observed in humans and many vertebrates) that preferentially produce offspring more resistant to both infectious and genetic disease. Recent experiments are beginning to discriminate the relative importance of these different disease-reducing mechanisms.


---MHC, is Major Histocompatibility Complex, and it is expressed to tag cells as 'Not Self', which then results in specialised immune cells comming along to wipe them out.

We are finding that the brains neurons has co-opted the system, and in this case, perhaps gone even further, likely using this immune-brain communication to ascertain if the offspring combining different individuals genes would result in cells that attacked its own body or were attacked by the mother. One simple process is that immune cells are mobile and get into the fetus , thus the mother sends in mature cells into the infant. These could trigger auto-immune attack, so it would help obviously that the father does not have an incompatibility which may be passed onto the child. We already suspect that maternal immune cells trigger morphological changes in target tissues based on immune responses in the mothers organs, so that lung inflammation is triggered in the infant as well, for example, showing that immune functions have profound effects and a lot of screening is desired.

This is potentially disasterous, as some women dont bother to screen their childrens fathers for immune compatibility if they are ordering sperm through a company. It may also help explain many unexplained early stage natural miscarriages.


It also supports an earlier suggestion by myself - that the brain evolved out of the immune system.

This in turn would support the notion that an early role for evolving neurons might have been to control and direct tissue organisation, which would lead onto some interesting things.