Tubulovesicular structures (TVS): virus-like particles specific for all subacute spongiform virus...

Tubulovesicular structures (TVS) are virus-like particles specific for all the subacute spongiform virus encephalopathies (SSVE). I report here the presence of TVS in the highest range of naturally occurring and experimentally induced SSVE studied so far: natural and experimental Creutzfeld-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome, natural bovine spongiform encephalopathy (BSE) and BSE transmitted to pigs and four models of experimental scrapie in hamsters. TVS are spherical particles, approximately 30 nm in diameter. They are observed at both sides of synaptic cleft (i.e. in dendrites and axonal preterminals and terminals). By the ultrastructural criteria, TVS are easily differentiated from other spherical or tubular elements of the nervous system: microtubules, synaptic vesicles, multivesicular bodies and glycogen granules. The number of affected processes roughly correlates with infectivity titre. Their significance is unknown!