Fig. 5: Immune responses to PCV13 in mice strongly depend on the gut microbiota and signalling through a MyD88-dependent pathway.
From: Bifidobacteria support optimal infant vaccine responses
a, PCV13-specific IgGtotal in sera from GF (n = 9) and SPF (n = 10) mice vaccinated with two doses of PCV13. Mock, PBS-vaccinated mice (n = 3). b–d, Frequencies and total numbers of total GC B cells (b) or CRM197+ GC B cells (c) in the spleens of mock-vaccinated mice (n = 9) and PCV13-vaccinated GF (n = 10) and SPF (n = 10) mice at 2 weeks postboost; and frequencies and total numbers of TFH cells (d) in the spleens of these mice. e, CD86 mean fluorescence intensity (MFI) on indicated myeloid cell populations in the dLN of GF and SPF mice 24 h following PCV13 or mock vaccination (n = 5 mice per group). f, PCV13-specific IgGtotal antibodies in the serum of mock-vaccinated mice (n = 5) and PCV13-vaccinated Myd88−/− (n = 10) and littermate wild-type (n = 10) mice. g, PCV13-specific IgGtotal in the serum of mock-vaccinated mice (n = 5) and PCV13-vaccinated (two doses intraperitoneally, 2 weeks apart) SPF (n = 10) and GF (n = 9) mice, and GF mice born to dams colonized with a consortium of Bifidobacterium species in pregnancy and administered these strains again at days 7 and 14 postbirth (GF + Bif, n = 6). Data shown are at 2 weeks postboost. h, Frequencies and total numbers of GC B cells in the spleens of mice from g at 2 weeks postboost. i,j, PCV13-specific IgGtotal (i) and IgG1 (j) in the sera of mock-vaccinated mice (n = 3), SPF mice (n = 8), GF mice (n = 8 mice), and GF mice colonized with probiotic strains L. acidophilus and B. bifidum at day 21 of life (GF + Probiotic, n = 7). Mice were vaccinated at day 28 of life. Data in a–j represent the mean ± s.e.m. Data in a–d are representative of three or more independent experiments; data in e–j are representative of two independent experiments. Statistical significance was assessed in a, f, i and j using two-way analysis of variance with Tukey’s posttest analysis for multiple comparisons, in b–e using two-tailed Student’s t-tests, and in g and h using one-way analysis of variance with Dunnett’s posttest analysis for multiple comparisons. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.001; NS, not significant. Exact P values are provided in the source data.
