An Avirulent Mutant of Rabies Virus Is Unable To Infect Motoneurons In Vivo and In Vitro

Abstract

An antigenic double mutant of rabies virus (challenge virus standard [CVS] strain) was selected by successive use of two neutralizing antiglycoprotein monoclonal antibodies, both specific for antigenic site III. This mutant differed from the original virus strain by two amino acid substitutions in the ectodomain of the glycoprotein. The lysine in position 330 and the arginine in position 333 were replaced by asparagine and methionine, respectively. This double mutant was not pathogenic for adult mice. When injected intramuscularly into the forelimbs of adult mice, this virus could not penetrate the nervous system, either by the motor or by the sensory route, while respective single mutants infected motoneurons in the spinal cord and sensory neurons in the dorsal root ganglia. In vitro experiments showed that the double mutant was able to infect BHK cells, neuroblastoma cells, and freshly prepared embryonic motoneurons, albeit with a lower efficiency than the CVS strain. Upon further incubation at 37°C, the motoneurons became resistant to infection by the mutant while remaining permissive to CVS infection. These results suggest that rabies virus uses different types of receptors: a molecule which is ubiquitously expressed at the surface of continuous cell lines and which is recognized by both CVS and the double mutant and a neuron-specific molecule which is not recognized by the double mutant.

Mutation of neutralizing/antibody-dependent enhancing epitope on spike protein and 7b gene of feline infectious peritonitis virus: Influences of viral replication in monocytes/macrophages and virulence in cats

“…Mar mutants of MHV, Ross River virus, rabies virus, and Venezuelan equine encephalitis virus became less virulent than their parent strains (Coulon et al, 1998;Johnson et al, 1990;Vrati et al, 1996;Wang et al, 1992). However, the virulence of mar mutant virus of FIPV in cats remains unexamined.…”

Evolution of Cell Recognition by Viruses: A Source of Biological Novelty with Medical Implications

“…In vitro experiments showed that the double mutant was able to infect BHK cells, neuroblastoma cells, and freshly prepared embryonic motoneurons, albeit with a lower efficiency than the parental strain CVS. Upon further incubation at 37 C, the motoneurons became resistant to infection by the mutant while remaining permissive to infection by the CVS strain (Coulon et al, 1998). Thus, rabies virus can use different types of receptors: a molecule that is expressed ubiquitously at the surface of continuous cell lines and that is recognized by both CVS and the double mutant and a neuron-specific molecule that is not recognized by the double mutant.…”

Rabies-based vaccine induces potent immune responses against Nipah virus

“…28 To further increase the safety profile of the vector, an arginine to glutamic acid mutation was introduced at amino acid position 333 of RABV G, which greatly reduces neurovirulence. 23,29,30 To develop full-length NIPARAB cDNA for use in recovery of the recombinant virus, we inserted a codon-optimized version of NiV G (Bangladesh strain) into the BNSP333 vector in between RABV N and P genes. This cDNA serves as the antigenome template from which single-stranded negative-sense RNA genomes are made.…”