Effect of expression level on immune responses to recombinant oral Salmonella enterica serovar Typhimurium vaccines

摘要: Live, attenuated Salmonella has been used to express heterologous antigens for development of oral vaccines. Often, expression must be regulated because deleterious effects on the vector. The effect varying levels immune response parameters not well defined. In this study we introduced mutations in -10 region trc promoter plasmid generate series vaccine strains with different a model antigen, hemagglutinin HagB from Porphyromonas gingivalis. There was no difference growth rates containing wild-type, mutant plasmids or empty primary IgG serum mice orally immunized wild-type strain peaked 3-4 weeks earlier than intermediate level strains, suggesting that high may favor an response. While there trend anti-HagB recall responses correlate higher level, peak were significantly even as low 33% wild-type. A similar terms seen and salivary IgA. subclass predominately IgG2a regardless consistent Th1 These data suggest isotype distribution, T helper cell profile are largely unaffected over wide range levels.