Wednesday June 11, 2003
Boston Cure Project for Multiple Sclerosis
"A team of Japanese scientists recently discovered a critical step in the process through which oligodendrocyte precursor cells (OPCs) mature to become oligodendrocytes and start producing myelin. By studying oligo development in newborn mice, they found that a molecule involved in the activation of various immune responses, the common gamma chain of immunoglobulin Fc receptors (FcRgamma), plays a critical role. This receptor is expressed by OPCs, and when it is stimulated, the OPCs begin to adopt the shape of oligodendrocytes, express myelin basic protein, and extend myelin processes. Mice that are born lacking this receptor or other molecules involved in the pathway are unable to produce adequate myelination in their central nervous system.
According to the study, it is not yet known what stimulates FcRgamma to induce these changes in OPCs. However, one possible candidate is the antibody class IgG, which can interact with FcRGamma. IgG from the mother may be present in the neonatal brain, and perhaps this is what stimulates FcRgamma in the initial myelination of the CNS. After maturation, IgG is barred from the CNS by the blood-brain barrier, but lapses in this barrier may admit access to IgG during periods of inflammation. Does or could IgG help stimulate remyelination in diseases like MS? That's not known yet either, but it represents a potentially useful line of inquiry in the field of neuroregeneration."
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