Creation of matrix protein gene variants of two serotypes of XXXX virus as prime-boost vaccine vectors.

@entity1 @entity25310 @entity72181 @entity72176 @entity72180 @entity72183 @entity19 @entity72177 @entity8310 @entity72179 @entity51 @entity521 @entity72178 @entity72182
To take advantage of live @entity8310 viruses (rVSVs) as vaccine vectors for their high yield and for their induction of strong and long-lasting immune responses, it is necessary to make live vaccine vectors safe for use without losing their immunogenicity. We have generated safer and highly efficient recombinant VSV vaccine vectors by combining the @entity25310 mutation in the M gene of serotype VSV-Indiana (VSVInd) with a temperature-sensitive mutation (tsO23) of the VSVInd Orsay strain. In addition, we have generated two new serotype VSV-New Jersey (VSVNJ) vaccine vectors by combining @entity72176 and @entity25310 mutations with @entity72177 and @entity72178 mutations in the M gene, rVSVNJ( @entity72179 ) [rVSVNJ(GMM)] and VSVNJ( @entity72180 ) [rVSVNJ(GMML)]. The combined mutations @entity72181 , @entity25310 , and @entity72182 in the M protein of VSVInd significantly reduced the burst size of the virus by up to 10,000-fold at 37  C without affecting the level of protein expression. BHK21 cells and SH-SY5Y @entity1 @entity521 cells infected with rVSVInd(GML), rVSVNJ(GMM), and rVSVNJ(GMML) showed significantly reduced cytopathic effects in vitro at 37  C, and @entity19 injected with 1 million infectious virus particles of these mutants into the brain showed no @entity51 or any other adverse effects. In order to increase the stability of the temperature-sensitive mutant, we have replaced the phenylalanine with alanine. This will change all three nucleotides from UUG (leucine) to GCA (alanine). The resulting @entity72183 mutant showed the temperature-sensitive phenotype of rVSVInd(GML) and increased stability. Twenty consecutive passages of rVSVInd(GML) with an @entity72183 mutation did not convert back to leucine (UUG) at position 111 in the M protein gene. IMPORTANCE: Recombinant @entity8310 viruses as live vaccine vectors are very effective in expressing foreign genes and inducing adaptive T cell and B cell immune responses. As with any other live viruses in @entity1 or animals, the use of live rVSVs as vaccine vectors demands the utmost safety. Our strategy to attenuate rVSVInd by utilizing a temperature-sensitive assembly-defective mutation of @entity72183 and combining it with an @entity25310 mutation in the M protein of rVSVInd significantly reduced the pathogenicity of the virus while maintaining highly effective virus production. We believe our new temperature-sensitive M gene mutant of rVSVInd(GML) and M gene mutants of rVSVNJ(GMM) and rVSVNJ(GMML) add excellent vaccine vectors to the pool of live viral vectors.
