Autoimmune T-Cell Reactivity to Myelin Proteolipids and Glycolipids in Multiple Sclerosis

Table 1

Some of the constituents of myelin and their relative distribution (assembled from information in [2, 48, 170–175]).

Constituent	CNS myelin	PNS myelin
Myelin proteins (make up 20–30% w/w of myelin)
Myelin proteolipid protein (PLP)/DM20	>50%*; (PLP > DM20)	0.05%; (DM20 > PLP)^†
Myelin basic protein (MBP, also known as P1)	30%	5–15%^††
Oligodendrocyte-specific protein (OSP)	7%	Not detected
2′,3′-Cyclic-nucleotide 3′-phosphodiesterase (CNPase)	2–4%	0.2%
Myelin associated glycoprotein (MAG)	1%	0.1%
Myelin oligodendrocyte glycoprotein (MOG)	0.01–0.05%	Not detected
P0 (glycoprotein)	Not detected	50%
P2	<0.01%	5–10%^††
PMP22	<0.01%	5–10%^††
Myelin lipids (make up 70–80% of total dry weight of myelin)
Galactocerebroside (GalC)	23%	~10%
Sulphatide	4%	~2%
Gangliosides	0.1–0.3%	~0.1%¶

∗Percentages represent the proportion of the molecule within the whole class of molecule; for example, >50% of the total protein fraction is PLP
^†PLP and DM20, the alternatively spliced isoform of PLP, are present at very low concentrations in Schwann cells, but are not inserted into the PNS myelin membrane.
^††Amounts vary depending on the peripheral nerves used as a source of tissue.
¶One of the most abundant gangliosides in human PNS myelin is LM1, which is not present in CNS myelin.