Figure 2. Ggta1 deletion enhances IgA responses to the gut microbiota.

(A) Relative binding of IgA in the serum of Ggta1^+/+ (n = 10) and GF Ggta1^+/+ (n = 5) mice to fecal extract from Ggta1^+/+ mice, and Ggta1^-/- (n = 6) and GF Ggta1^-/- (n = 6) mice to fecal extract from Ggta1^-/- mice; one experiment. (B) Relative binding of IgA in the serum of GF Ggta1^+/+ (n = 7) and GF Ggta1^-/- (n = 10) mice to cecal extract from Ggta1^-/- mice at indicated time-points after colonization with cecal extract from Ggta1^-/- mice; two experiments. (C) Median Fluorescence Intensity (MFI) of αGal⁺ bacterial strains stained with BSI-B4 lectin relative to unstained control; seven experiments. (D) Representative flow cytometry plots showing bacteria stained for IgA and αGal in the small intestinal content of Ggta1^+/+ (n = 5) and Ggta1^-/- (n = 11) mice; four independent experiments. (E) Quantification of αGal⁺, IgA⁺, and IgA⁺αGal⁺ bacteria in the same samples as in (D). (F) Concentration of anti-αGal IgM in serum of Ggta1^+/+ (n = 2), Ggta1^-/- (n = 12), Igha^-/-Ggta1^+/+ (n = 10), and Igha^-/-Ggta1^-/- (n = 12) mice before and after streptomycin treatment, two experiments. (G) Concentration of anti-αGal IgG, in the same mice as (F). Symbols (A, B, E, F, G) are individual mice. Red bars (A, B, E, F, G) correspond to mean values. Error bars (A, B, C, E, F, G) correspond to SD. p Values in (A, B, F, G) calculated using Kruskal-Wallis test using Dunn’s multiple comparisons test and in (E) using Mann-Whitney test. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001, ns: not significant.

Figure 2—figure supplement 1. Ggta1 deletion enhances IgA responses to the gut microbiota.

(A) Concentration of total IgA in serum of Ggta1^+/+ (n = 9), GF Ggta1^+/+ (n = 5), Ggta1^-/- (n = 5) and GF Ggta1^-/- (n = 6) mice. (B) Concentration of total IgA in the small intestinal content of Ggta1^+/+ (n = 10), GF Ggta1^+/+ (n = 5), Ggta1^-/- (n = 10) and GF Ggta1^-/- (n = 5) mice. (C) Relative binding of IgA in the serum of GF Ggta1^+/+ (n = 5) and GF Ggta1^-/- (n = 5) mice to fecal extract from Ggta1^+/+ mice at indicated time-points after colonization with cecal extract from Ggta1^+/+ mice; two experiments. (D) Concentration of total IgA in serum of Ggta1^-/- (n = 7), Tcrb^-/-Ggta1^-/- (n = 12) mice. (E) Representative plots showing the gating strategy for staining of intestinal content with Syto41, BSI-B4, and Anti-IgA. (F) Quantification of αGal⁺, IgA⁺, and IgA⁺αGal⁺ bacteria in the cecum, colon, and feces of the same mice as in Figure 2D–E. Symbols (A, B, C, D, F) are individual mice. Red bars (A, B, C, D, F) correspond to mean values. Error bars (A, B, C, D, F) correspond to SD. P values in (A, B, C) calculated using Kruskal-Wallis test using Dunn’s multiple comparisons test and in (D, F) using Mann-Whitney test. *p<0.05, **p<0.01, ns: not significant.

Figure 2—figure supplement 2. αGal expression by probiotic bacteria.

Representative flow cytometry plots of the data in Figure 2C showing probiotic bacterial strains unstained or stained with BSI-B4 lectin.