>> Richard, I must admit to not knowing as much as I should about the status of immune response systems within the CNS.<<
That makes two of us, so let's keep talking until an expert drops in.
I'm used to seeing surprises when testing is extended to humans or to a larger sample of humans in expanded trials. Thus the basic skepticism.
I come from a camp that says that anti-viral immune responses in the brain can do more damage than an unchecked virus, from old Michael Oldstone-like observations. That's a pretty old camp. Also, I come from a stance that certain diseases such as MS involve an inflammatory component that does not involve exogenous insult.
I'm just throwing out "show me" questions. If the answers are firmly in-hand, then we can turn to other questions..... the competitive benefit relative to projects such as those at GLFD/AMGN and VRTX, for example.
This is neuro stuff. I'm just skimming, out of my league, asking questions. If someone can provide simple answers that will make me a devout believer, then I'll get rich at the expense of being a public idiot. Tisk, tisk.
If this is all open-and-shut given (1) the preclinical and clinical data that is already in-hand, and (2) the methods that exist for isolation and expansion of the donor cells, then a simple "letter to the shareholders" from CTII should boost the market cap to about $1 billion, overnight. Could you please have them draft that document and send it to me for editing, one day before release? One trading day, that is.
So.... yeah, there's lots of data out there that indicates that primary immune responses are difficult to initiate in the brain. I'm extremely interested in this concept, and would love to see CTII carry it forward with success. Just saying that, from my perspective, there are lots of outstanding questions. For example, is there a "stroma-like" microenvironment that is optimal for success? Have there been other cell types in the fetal transplants, apart from the stem cells, that have "enabled" the stem cells?
BTW..... some would say that the success of embryonic neural transplants as a treatment for patients with Parkinson's disease has been limited.
For women who believe that men think with their balls.......
Nat Biotechnol 1996 Dec;14(13):1692-5
Testis-derived Sertoli cells survive and provide localized
immunoprotection for xenografts in rat brain.
Sanberg PR, Borlongan CV, Saporta S, Cameron DF
Department of Surgery, University of South Florida College of Medicine, Tampa 33612, USA. psanberg@com1.med.usf.edu
Transplantation of neural tissue into the mammalian central nervous system has become an alternative treatment for
neurodegenerative disorders such as Parkinson's disease. Logistical and ethical problems in the clinical use of human fetal neural
grafts as a source of dopamine for Parkinson's disease patients has hastened a search for successful ways to use animal
dopaminergic cells for human transplantation. The present study demonstrates that transplanted testis-derived Sertoli cells into
adult rat brains survive. Furthermore, when cotransplanted with bovine adrenal chromaffin cells (xenograft), Sertoli cells
produce localized immunoprotection, suppress microglial response and allow the bovine cells to survive in the rat brain without
continuous systemic immunosuppressive drugs. These novel features support Sertoli cells as a viable graft source for facilitating
the use of xenotransplantation for Parkinson's disease and suggest their use as facilitators, (i.e., localized immunosuppression)
for cell transplantation in general. |
