CD40 and disease arising from reactivation of latent virus: APCs from C57Bl/6 mice infected with γHV-68 AC-RTA express CD40, during the antigen presentation phase of EAE at levels comparable to naïve EAE mice (Fig. 4) rather than the increased expression observed in γHV-68 latently infected mice (Fig. 4) thereby associating latent infection with increased CD40 surface expression and likely co-stimulation.