C3 necessary for 'maximal' EAE

[TwistedHelix]

Complement is part of the immune system. C3b is an Opsonin, (helps white blood cells to bind to foreign tissue), and it sounds to me as if C3b mistakenly binds to self-tissue, thus bonding it to white blood cells, which then destroy it.
C3a also can trigger the release of histamine, which may play a part in some forms of MS:

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