Production of native flagellin from Salmonella Typhimurium in a bioreactor and purification by tangential ultrafiltration

Flagellin is the structural protein and most abundant component of bacterial flagella. The flagellum filament contains around 20,000 – 100,000 subunits of 50 kDa flagellin that can have diversebiotechnological applications such as vaccine adjuvant and cellular protector during chemo- and radiotherapy.The main aim of this work was to study a production process of purified native FliC flagellin of Salmonella Typhimurium. The culture conditions in shakers were established with medium devoid of animal-derived components. In bioreactors, culture conditions were established in order to obtain flagellin from the culture supernatant by tangential ultrafiltration (TUF). The concentrated 750 kDa cut-off TUF fraction had a purification factor of 1.5 and a recovery yield of 52.2% for flagellin. The volumetric production of flagellin using the described procedure achieved around 307 mg/L of culture, which represented a significant improvement over previously reported methods. These results permit the development of production and purification processes that can be easily scaled up.

Anti-flagellin antibody responses elicited in mice orally immunized with attenuated Salmonella enterica serovar Typhimurium vaccine strains.

In the present study we investigated the flagellin-specific serum (IgG) and fecal (IgA) antibody responses elicited in BALB/c mice immunized with isogenic mutant derivatives of the attenuated Salmonella enterica serovar Typhimurium (S. Typhimurium) SL3261 strain expressing phase 1 (FliCi), phase 2 (FljB), or no endogenous flagellin. The data reported here indicate that mice orally immunized with recombinant S. Typhimurium strains do not mount significant systemic or secreted antibody responses to FliCi, FljB or heterologous B-cell epitopes genetically fused to FliCi. These findings are particularly relevant for those interested in the use of flagellins as molecular carriers of heterologous antigens vectored by attenuated S. Typhimurium strains.

Anti-flagellin antibody responses elicited in mice orally immunized with attenuated Salmonella enterica serovar Typhimurium vaccine strains

In the present study we investigated the flagellin-specific serum (IgG) and fecal (IgA) antibody responses elicited in BALB/c mice immunized with isogenic mutant derivatives of the attenuated Salmonella enterica serovar Typhimurium (S. Typhimurium) SL3261 strain expressing phase 1 (FliCi), phase 2 (FljB), or no endogenous flagellin. The data reported here indicate that mice orally immunized with recombinant S. Typhimurium strains do not mount significant systemic or secreted antibody responses to FliCi, FljB or heterologous B-cell epitopes genetically fused to FliCi. These findings are particularly relevant for those interested in the use of flagellins as molecular carriers of heterologous antigens vectored by attenuated S. Typhimurium strains.