Immunosuppressive factor from milk-teeth

Shimojima C, Takeuchi H, Jin S, Parajuli B, Hattori H, Suzumura A, Hibi H, Ueda M, Yamamoto A. Conditioned Medium from the Stem Cells of Human Exfoliated Deciduous Teeth Ameliorates Experimental Autoimmune Encephalomyelitis. J Immunol. 2016 Apr 6. pii: 1501457. [Epub ahead of print]

Multiple sclerosis (MS) is a major neuroinflammatory demyelinating disease of the CNS. Current MS treatments, including immunomodulators and immunosuppressants, do not result in complete remission. Stem cells from human exfoliated deciduous teeth (SHEDs) are mesenchymal stem cells derived from dental pulp. Both SHED and SHED-conditioned medium (SHED-CM) exhibit immunomodulatory and regenerative activities and have the potential to treat various diseases. In this study, we investigated the efficacy of SHED-CM in treating experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. EAE mice treated with a single injection of SHED-CM exhibited significantly improved disease scores, reduced demyelination and axonal injury, and reduced inflammatory cell infiltration and proinflammatory cytokine expression in the spinal cord, which was associated with a shift in the microglia/macrophage phenotype from M1 to M2. SHED-CM also inhibited the proliferation of myelin oligodendrocyte glycoprotein-specific CD4+T cells, as well as their production of proinflammatory cytokines in vitro. Treatment of EAE mice with the secreted ectodomain of sialic acid-binding Ig-like lectin-9, a major component of SHED-CM, recapitulated the effects of SHED-CM treatment. Our data suggest that SHED-CM and secreted ectodomain of sialic acid-binding Ig-like lectin-9 may be novel therapeutic treatments for autoimmune diseases, such as MS.

I picked this paper for the title. Its bonkers......stem cells from milk teeth what next?  Here they take the stem cells  into culture and find that a molecule produced inhibit auto immunity, This is sialic acid-binding Ig-like lectin-9. This inhibits EAE. However this is the inference you get when you read the paper.

But let's look at the real data.

So as you can see there is an inhibitory effect and it promotes better recovery because it blocks the accumulation of damage. So you get infiltrates, myelin and nerve loss. Looking at the histology presented there is limited damage to be seen in the the stem cell media treated animals, so nothing needed for repair:-) and the data shows if you can find the factor doing the work you don't need stem cells just the factor. 

Maybe the cells need to go in after the damage has been done and then lets see what happens

We are spending millions on trials with stem cells. The mesenchymal stem cells must be ready for prime time I have heard people saying the trials show that the procedure is safe,but do they work. The same effect can be achieved with an immunomodulatory drugs