Figure 7.

Lactococcus lactis^pNZ-Apyr administration ensures a proficient IgA production in adulthood and improves IgA response to oral CT immunization in MAL mice

(A) Quantification of total fecal IgA by ELISA in 10-week-old CON mice, untreated MAL mice, and MAL mice treated with L. lactis^pNZ or L. lactis^pNZ-Apyr.

(B) Fecal LCN-2 concentration (ng/g feces), (Mann-Whitney U test). Data points represent individual mice, and statistics are displayed as mean ± SEM.

(C) Experimental design. After weaning, untreated MAL mice or MAL mice treated with L. lactis^pNZ or L. lactis^pNZ-Apyr were maintained in low-protein diet and were gavaged with L. Lactis^pNZ or L. lactis^pNZ-Apyr twice a week for the entire duration of the experiment. At 10 weeks of age, CON mice and untreated MAL mice or MAL mice treated with L. lactis^pNZ or L. lactis^pNZ-Apyr were orally immunized with CT at day 70, 77, and 84. At day 91, mice were analyzed.

(D) CT-specific IgA-secreting plasma cells measured by ELISPOT assay in the lamina propria of the small intestine from CON mice, untreated MAL mice, and MAL mice treated with L. lactis^pNZ or L. lactis^pNZ-Apyr.

(E) Quantification of CT-specific IgA to total IgA ratio in feces of CON mice, untreated MAL mice, and MAL mice treated with L. lactis^pNZ or L. lactis^pNZ-Apyr (Mann-Whitney U test). Data points represent individual mice, and statistics are displayed as mean ± SEM. ∗p < 0.05; ∗∗p < 0.01.