The role of complement in immunological demyelination of the mammalian spinal cord.
METHODS
Specificity of serum complement component to elicit immunological demyelination.


OBJECTIVE
To assess the role of complement components and pathways in experimental immunological demyelination of the adult rat spinal cord.


METHODS
ICORD, University of British Columbia, Vancouver, Canada.


METHODS
We used 32 adult male Sprague-Dawley rats, of approximately 220 g weight.


METHODS
Rats received intraspinal infusions of demyelinating reagents, delivered by osmotic minipump, for a 7-day infusion at 0.5 microl/h. Reagents consisted of a polyclonal antibody to galactocerebroside and human serum complement. Complement sera deficient for a single component were used to assess the role of the alternative pathway, the classical pathway, and the membrane attack complex. Demyelination was assessed, at 7 days, ultrastructurally.


RESULTS
Removal of C3 protein, common to classical and alternative complement pathways, or C4 protein, a classical pathway protein, resulted in no demyelination. However, complement deficient in Factor B, an alternative pathway protein, produced effective demyelination. Upon removal of C5 or C6, membrane attack complex proteins, demyelination was also observed.


CONCLUSIONS
This suggests that the classical pathway is sufficient for the protocol to demyelinate the adult rat spinal cord, and that the membrane attack complex is also not required.
Dyer
J K
JK
International Collaboration on Repair Discoveries (ICORD), University of British Columbia and Vancouver Hospital, Vancouver, BC, Canada.
Bourque
J A
JA
Steeves
J D
JD
D000818:Animals; D001369:Axons / Q000276:immunology* / Q000473:pathology*; D003167:Complement Activation / Q000276:immunology*; D003165:Complement System Proteins / Q000276:immunology*; D003711:Demyelinating Diseases / Q000276:immunology* / Q000473:pathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000276:immunology* / Q000473:pathology*
D003165:Complement System Proteins