Table 7.2.

Possible mechanisms of virus-induced demyelination

Direct viral effects

Virus infection of oligodendrocytes causing demyelination through cell lysis or an alteration in cell metabolism

Myelin membrane destruction by viral proteins

Virus-induced immune-mediated reactions

Antibody or cell-mediated reactions to viral antigens on cell membranes

Sensitization of host to myelin antigens (epitope spreading)

Breakdown of myelin by infection with release into the circulation

Incorporation of myelin antigens into virus envelope

Modification of antigenicity of myelin membranes

Cross-reacting antigens between virus and myelin proteins (molecular mimickry)

Cytokine or protease demyelination (bystander effect)

Viral disruption of regulatory mechanisms of the immune system

Modified from Johnson (1985).