The Anterograde Transport of Rabies Virus in Rat Sensory Dorsal Root Ganglia Neurons

Abstract

SUMMARYWe have previously described the capacity of neurites extending from cultured rat sensory dorsal root ganglia (DRG) neurons to transport rabies virus through axoplasm in the retrograde direction. Here we report the infection of cultured neurons derived from the DRG and the subsequent anterograde transport of rabies virus from the infected cell somas through the extending neurites to its release into the culture supernatant. Viral transport was monitored by titration of the virus yield in the external compartment. Both early and late transport mechanisms of rabies virions were identified. The first one occurred a few hours post-infection and was undetectable 6 h later, before the initiation of viral replication. The velocity of this first wave of infective virions was in the range of 100 to 400 mm/day. The early viral transport was probably the result of a direct translocation of infective virions from the somatic site of entry to the neuritic extensions and subsequent release into the culture medium without replication in the cellular perikaryon. The second virus transport peak was detected 48 h post-infection. In this case, the virions detected in the neuritic compartment were presumably the progeny of the inoculated virus which had replicated in the perikaryon before the viral transport occurs. Using a four-compartment culture device we were able to demonstrate, simultaneously, retrograde and anterograde transport of the virus. The presence of antirabies serum in contact with the exposed neurites did not inhibit either the retrograde or the anterograde transport mechanisms. The viral release from the neuritic extensions after the fast anterograde transport was evaluated to be in the range of 150 to 300 infectious virions per bundle of neurites per day.

Identifying local and descending inputs for primary sensory neurons

“…Previous tracing studies using rabies virus consistently demonstrated that peripheral uptake of rabies virus typically occurs at motor terminals and propagates retrogradely via exclusive trans-synaptic transfer into presynaptic neurons (23,33,55). However, in animal species such as mice, which have a particular affinity for fixed rabies strains (due to their passage history), the virus can enter into peripheral terminals of sensory neurons and move in an anterograde manner (24)(25)(26). The question is whether the spread of rabies to other neurons from infected primary sensory neurons happens primarily with presynaptic partners or nonselectively to any nearby neurons.…”

“…Consequently, through intraganglion spreading of the replicated viruses, more DRG neurons were labeled in Avil-Cre RΦGT mice (~3,600) than in Trpv1-Cre RΦGT mice (~2,300). the commonly used "fixed" strains of rabies virus could infect mouse primary sensory neurons from axon terminals, could be transported anterogradely in these neurons, and could be released from their axon terminals (24)(25)(26). We have previously developed a mouse line that enables Cre-dependent complementation of the deficient rabies virus (RΦGT mouse) (27,28).…”

Distribución de calbindina y parvoalbúmina y efecto del virus de la rabia sobre su expresión en la médula espinal de ratones

“…Ocasionalmente, el virus puede llegar directamente al sistema nervioso central sin replicarse en los músculos (6). Las partículas virales ingresan a las células nerviosas por endocitosis, en la terminal sináptica de la placa neuromuscular, y viajan a través de los tractos nerviosos por medio del transporte axonal retrógrado (2,5); así logran invadir la médula espinal y posteriormente el encéfalo (7).…”

The dynein light chain 8 binding motif of rabies virus phosphoprotein promotes efficient viral transcription

“…Yet, the molecular basis for the transport of the RV particle remains unclear and controversial. Most transneuronal studies of the CNS in nonhuman primates (5,6) and mice (7,8) reveal that fixed (laboratory-adapted) strains of RV spread exclusively in the retrograde direction; however, past in vitro and in vivo studies suggest that anterograde transport might also be involved (7,(9)(10)(11). The discovery that the dynein light chain, LC8 (DNLC1), interacts with the RV phosphoprotein (RVP) provides a putative molecular link between the virus and host cell transport system and, thus, a potential mechanism for the neuroinvasive property of RV.…”