Antibody responses induced by mucosal DNA vaccine encoding the codon-optimized F protein of human respiratory syncytial virus (RSV) delivered with attenuated Salmonella typhimurium
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Supported by the Beijing Natural Science Foundation of China (7092053)
Abstract:[Objective] In order to investigate antibody responses by musosal DNA vaccines encoding the codon-optimized F protein of human respiratory syncytial virus (RSV) delivered with attenuated Salmonella typhimurium aroA strain SL7207 (SL7207) via intranasal or intragastric routes.[Methods]After the codon-optimized F gene was synthesized,we constructed eukaryotic expression plasmid pcDNA3.1/Fsyn and transformed it into SL7207 to get recombinant SL7207 of SL7207/pcDNA3.1/Fsyn.Then,SL7207/pcDNA3.1/Fsyn was exploited to evaluate its immunogenicity in BALB/c mice administered intranasally or intragastrically. The resultant serum and mucosal antibody responses were analyzed by indirect ELISA. [Results]Compared with intragastric immunization group,intranasal immunization group achieved higher level of RSV specific serum IgG and secretion IgA (SIgA)(P<0.05).Moreover,F protein expressed by the codon-optimized F gene of Fsyn was of elevated immunogenicity,compared with wild type F (Fwt)(P<0.05).[Conclusion] Intranasal immunization and codon optimization approaches can improve antibody responses of RSV DNA vaccine delivered by attenuated Salmonella typhimurium aroA strain SL7207.