Fig 1.
Anti-OVA antibody levels in intestinal contents of immunized mice.
Immunization by intra-rectal route with ovalbumin as antigen (OVA), with cholera toxin (CT) (n = 14), Salmonella Typhimurium flagellin (FLA-ST) (n = 14), C. difficile flagellin (FliC) (n = 14) respectively as adjuvant and PBS administration for the control group (n = 14). Immunization by intra-peritoneal route with OVA as antigen and FliC as adjuvant (FliC IP) (n = 8). (A) Anti-OVA IgA level; (B) anti-OVA IgG level. *: statistically significant difference *: 0.01<p<0.05; **: 0.001<p<0.01; ***: p<0.001 (student t-test). Dotted-line corresponds to the cut-off value.
Fig 2.
Number of antibody producing cells specific to OVA in the intestinal lamina propria of immunized mice expressed in spot forming units (SFUs).
Immunization by intra-rectal route with ovalbumin as antigen (OVA), with cholera toxin (CT) (n = 5), Salmonella Typhimurium flagellin (FLA-ST) (n = 5), C. difficile flagellin (FliC) (n = 5) respectively as adjuvant and PBS administration for the control group (n = 5). Immunization by intra-peritoneal route with OVA as antigen and FliC as adjuvant (FliC IP) (n = 5). (A) Anti-OVA IgA producing cells count; (B) anti-OVA IgG producing cells count *: statistically significant difference p < 0.05 (Mann-Whitney U-test).
Fig 3.
Anti-OVA IgG level in sera of immunized mice.
Immunization by intra-rectal route with ovalbumin as antigen (OVA), with cholera toxin (CT) (n = 14), Salmonella Typhimurium flagellin (FLA-ST) (n = 14), C. difficile flagellin (FliC) (n = 14) respectively as adjuvant and PBS administration for the control group (n = 14). Immunization by intra-peritoneal route with OVA as antigen and FliC as adjuvant (FliC IP) (n = 8). D0: before immunization, D15: first immunization, D30: first boost, D45: second boost. *: statistically significant difference *: 0.01<p < 0.05; **: 0.001<p<0.01; ***: p<0.001 (student t-test). Dotted-line corresponds to the cut-off value.
Fig 4.
C. difficile colonization in vaccinated mice after challenge.
C. difficile count from day 1 to day 10 in feces of mice intra-rectally vaccinated with SlpA as antigen and FliC (n = 12) or CT (n = 12) as adjuvant compared to control group (n = 12). *: statistically significant difference between the control and vaccinated groups p < 0.05 (Mann-Whitney U-test).