Eukaryotic expression system complemented with expressivity of Semliki Forest Virus's RdRp and invasiveness of engineered Salmonella demonstrate promising potential for bacteria mediated gene therapy

Safety assessment of compliant, highly invasive, lipid A-altered, O-antigen-defected Salmonella strains as prospective vaccine delivery systems

“… Bacteria/plasmid Genotypic characteristics References S . Typhimurium JOL401 Wild-type (WT) Lab stock JOL911 Δ lon , Δ cpxR [ 13 ] JOL2500 Δ lon , Δ cpxR , Δ sifA , Δ asd [ 15 ] JOL3000 Δ lon , Δ cpxR , Δ rfaL , Δ pagL :: lpxE, Δ asd Lab stock JOL2782 JOL2500 carrying pJHL204-H1N1 HA In this study JOL2837 JOL3000 carrying pJHL204-H1N1 HA In this study E. coli DH5α E. coli F − Φ80dlacZΔM15Δ (lacZYA-argF) U169recA1 endA1 hsdR17(rk-mk + ) phoA supE44 thi1 gyr A96 relA1λ- Lab stock BL21(DE3) F – , ompT, hsdSB (rB – mB – ), dcm, gal, λ(DE3) Lab stock E. coli 232 F—λ—φ80Δ(lacZYA-argF) endA1 recA1 hadR17 deoR thi-1 glnV44 gyrA96 relA1 ΔasdA4 Lab stock F. tularensis Source for lpxE amplification Lab stock Plasmid pET28a( +) IPTG-inducible expression vector; Kanamycin resistance Novagen pJHL204 asd + , CMV promoter, SV40 promoter, pBR322 ori Lab stock pKD46 …”

“…Inoculated cells without infection were used as a control. An accepted protocol for infection was performed in which monolayers were washed with PBS and treated with gentamycin (100 µg/mL) for 2 h to eliminate extracellular bacteria [ 15 ].…”

“…Strains were treated with acidic stress at pH 4.0 and with oxidative stress at 1 mM and 5 mM H 2 O 2 for 30 min. The rate of survival based on the initial inoculum was assessed by plating on BGA [ 15 ] and confirmed the retention of a heterologous gene by heterologous antigen construct-specific primers.…”

“…The deletion of sifA from SPI-2 disrupted the integrity of Salmonella -containing vacuoles (SCVs) [ 14 ] and prevented escape from immune recognition. Thus, for release of a plasmid containing the target gene into the cytoplasm, the mutant strain Salmonella JOL2500 ( Δlon, ΔcpxR, ΔsifA ) with selective auxotrophy was developed as a vaccine vector system [ 15 ].…”

Salmonella-mediated oral delivery of multiple-target vaccine constructs with conserved and variable regions of SARS-CoV-2 protect against the Delta and Omicron variants in hamster

“…Some of the vaccine strategies include inactivated viral vaccines, live-attenuated vaccines, virus-vectored vaccines, protein subunit vaccines, virus-like particle vaccines and DNA and mRNA vaccines [ 12 ]. In this study, we specifically exploited the advantages of Salmonella -based vaccine with Semliki Forest virus (SFV) replicon which we have previously reported to efficiently amplify the target mRNA and deliver the antigens to the target tissues [ 13 , 14 ].…”