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. 2015 Jun;83(6):2420-9.
doi: 10.1128/IAI.00064-15. Epub 2015 Mar 30.

Oral tolerance failure upon neonatal gut colonization with Escherichia coli producing the genotoxin colibactin

Thomas Secher  1 , Delphine Payros  1 , Camille Brehin  1 , Michele Boury  1 , Claude Watrin  1 , Marion Gillet  2 , Isabelle Bernard-Cadenat  3 , Sandrine Menard  2 , Vassilia Theodorou  2 , Abdelhadi Saoudi  3 , Maiwenn Olier  4 , Eric Oswald  5
Affiliations

Oral tolerance failure upon neonatal gut colonization with Escherichia coli producing the genotoxin colibactin

Thomas Secher et al. Infect Immun. 2015 Jun.

Abstract

The intestinal barrier controls the balance between tolerance and immunity to luminal antigens. When this finely tuned equilibrium is deregulated, inflammatory disorders can occur. There is a concomitant increase, in urban populations of developed countries, of immune-mediated diseases along with a shift in Escherichia coli population from the declining phylogenetic group A to the newly dominant group B2, including commensal strains producing a genotoxin called colibactin that massively colonized the gut of neonates. Here, we showed that mother-to-offspring early gut colonization by colibactin-producing E. coli impairs intestinal permeability and enhances the transepithelial passage of luminal antigen, leading to an increased immune activation. Functionally, this was accompanied by a dramatic increase in local and systemic immune responses against a fed antigen, decreased regulatory T cell population, tolerogenic dendritic cells, and enhanced mucosal delayed-type hypersensitivity response. Conversely, the abolition of colibactin expression by mutagenesis abrogates the alteration of oral tolerance induced by neonatal colonization by E. coli. In conclusion, the vertical colonization by E. coli producing the genotoxin colibactin enhances intestinal translocation and subsequently alters oral tolerance. Thus, early colonization by E. coli from the newly dominant phylogenetic group B2, which produces colibactin, may represent a risk factor for the development of immune-mediated diseases.

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Figures

FIG 1
FIG 1
Colibactin impaired intestinal permeability and enhanced E. coli translocation in neonates. (a) FITC recovery at PND8 and PND15 in the sera of rats early colonized with E. coli wild-type (WT; ■), ΔclbA (□), or ΔclbA::clbA (▩) strains. The means ± the standard errors of the mean (SEM) for n = 6 rats are shown (*, P < 0.05; **, P < 0.01). (b) E. coli enumeration in blood at PND8, PND15, and PND28. The means for E. coli CFU (log) per ml ± the SEM for n = 16 to 26 (PND8 and PND15) or n = 6 to 12 (PND28) rats are shown (*, P < 0.05; **, P < 0.01; ***, P < 0.001). (c) Prevalence of blood E. coli translocation at PND8, PND15, and PND28. The absolute numbers of rats with (■) or without (□) blood translocation according to the expression of colibactin by E. coli for n = 16 to 26 (PND8 and PND15) or n = 6 to 12 (PND28) rats are shown (*, P < 0.05; **, P < 0.01). (d) E. coli enumeration in mLN at PND8, PND15, and PND28. The means for E. coli CFU (log) per g ± the SEM for n = 12 (PND8 and 15) or n = 8 (PND28) rats are shown (*, P < 0.05; ****, P < 0.001). (e) Prevalence of mLN E. coli translocation at PND8, PND15, and PND28. The absolute numbers of rats with or without blood translocation according to the expression of colibactin by E. coli for n = 12 (PND8 and 15) or n = 8 (PND28) rats are shown (*, P < 0.05; **, P < 0.01).
FIG 2
FIG 2
Early gut colonization by colibactin-producing E. coli alters PP homeostasis. (a) Using chamber analysis, paracellular permeability of PP from rats colonized with E. coli WT, ΔclbA, or ΔclbA::clbA strains was assessed at PND28 by measuring mucosal to serosal flux to FITC-dextran. The means ± the SEM for n = 10 rats are shown (*, P < 0.05; ***, P < 0.001). (b) Using chamber analysis of PP, the permeability to chemically killed K-12 Alexa 488-conjugated E. coli was assessed at PND28. The means ± the SEM for n = 7 (E. coli WT and ΔclbA) and n = 11 (E. coli ΔclbA::clbA) rats are shown (*, P < 0.05). (c) E. coli enumeration in PP at PND28. The means of E. coli CFU (log) per g ± the SEM for n = 20 (E. coli WT and ΔclbA) or n = 12 (E. coli ΔclbA::clbA) rats are shown (*, P < 0.05; **, P < 0.01; ***, P < 0.001). (d) IFN-γ production in PP was determined by ELISA at PND28. The mean levels of IFN-γ per g ± the SEM for n = 11 (E. coli ΔclbA::clbA) or n = 7 (E. coli WT and ΔclbA) rats are shown (*, P < 0.05).
FIG 3
FIG 3
Early gut colonization by colibactin-producing E. coli impaired tolerance against luminal antigen. (a to d) OVA-tolerized adult rats early colonized by E. coli WT, ΔclbA, or ΔclbA::clbA strains were analyzed for serum levels of OVA-specific immunoglobulin. The mean IgG (a), IgG2a (b), IgG2b (c), and IgG1 (d) titers ± the SEM for n = 18 (E. coli WT) and n = 20 (ΔclbA and ΔclbA::clbA) rats are shown (**, P < 0.01; ***, P < 0.001). (e) IFN-γ production in the jejunum was determined by ELISA. The mean levels of IFN-γ per g ± the SEM for n = 9 rats are shown (**, P < 0.01). (f and g) OVA-tolerized (tol, full bars) or sensitized (sen, dotted bars) adult rats early colonized by E. coli WT, ΔclbA, and ΔclbA::clbA strains were analyzed for cytokine production analysis in OVA-restimulated mLN cells after 3 days of culture. The mean IFN-γ (f) and IL-17 (g) production ± the SEM for n = 8 animals is shown (***, P < 0.001).
FIG 4
FIG 4
Diminished oral tolerance in animals early colonized by colibactin-producing E. coli is correlated to a defect in regulatory populations. (a) Percentage of TCRab+ CD4+ CD25+ FoxP3+ cells in mLN of OVA-tolerized rats early colonized by E. coli WT, ΔclbA, or ΔclbA::clbA strains. The means ± the SEM for 10 rats are shown (*, P < 0.05; **, P < 0.01). (b) Percentage of CD103+ CD11c+ MHC-II+ cells in mLN of OVA-tolerized rats early colonized by E. coli WT, ΔclbA, or ΔclbA::clbA strains. The means ± the SEM for 8 rats are shown (*, P < 0.05; **, P < 0.01). (c and d) Percentage of TCRab+ CD4+ (c) and CD8+ (d) cells in mLN of OVA-tolerized rats early colonized by E. coli WT, ΔclbA, or ΔclbA::clbA strains. The means ± the SEM for 10 rats are shown (**, P < 0.01).
FIG 5
FIG 5
Early gut colonization with colibactin-producing E. coli enhanced intestinal DTH responses against luminal antigen. (a) Representative microphotographs of jejunum H&E-stained sections from OVA-challenged adult rats early colonized by E. coli WT, ΔclbA, or ΔclbA::clbA strains. Scale bar, 200 μm. Continuous arrows indicate cell infiltrates, and dotted arrows indicate mucosal ulcerations. (b) Histological evaluation of jejunum inflammation and damage in blinded fashion. The means ± the SEM for n = 7 (E. coli WT and ΔclbA) and n = 11 (E. coli ΔclbA::clbA) rats are shown (*, P < 0.05; ***, P < 0.001). (c and d) Levels of proinflammatory cytokines IL-6 (c) and TNF-α (d) production in jejunum homogenates as determined by ELISA. The mean levels of IL-6 or TNF per μg of tissue ± the SEM for n = 7 (E. coli WT and ΔclbA) and n = 11 (E. coli ΔclbA::clbA) rats are shown (*, P < 0.05). (e) Representative microphotographs of colon H&E-stained sections from OVA-challenged rats. Scale bars, 200 μm. Continuous arrows indicate cell infiltrates, and dotted arrows indicate mucosal ulcerations. (f) Histological evaluation of colon inflammation and damage in a blinded fashion. The means ± the SEM for n = 7 (E. coli WT and ΔclbA) and n = 11 (E. coli ΔclbA::clbA) rats are shown (*, P < 0.05). (g) MPO quantification in the colon of OVA-tolerized rats. The means ± the SEM for n = 7 (E. coli WT and ΔclbA) and n = 11 (E. coli ΔclbA::clbA) rats are shown (*, P < 0.05).
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References

    1. Qin J, Li R, Raes J, Arumugam M, Burgdorf KS, Manichanh C, Nielsen T, Pons N, Levenez F, Yamada T, Mende DR, Li J, Xu J, Li S, Li D, Cao J, Wang B, Liang H, Zheng H, Xie Y, Tap J, Lepage P, Bertalan M, Batto JM, Hansen T, Le Paslier D, Linneberg A, Nielsen HB, Pelletier E, Renault P, Sicheritz-Ponten T, Turner K, Zhu H, Yu C, Li S, Jian M, Zhou Y, Li Y, Zhang X, Li S, Qin N, Yang H, Wang J, Brunak S, Dore J, Guarner F, Kristiansen K, Pedersen O, Parkhill J, Weissenbach J, et al. . 2010. A human gut microbial gene catalogue established by metagenomic sequencing. Nature 464:59–65. doi:10.1038/nature08821. - DOI - PMC - PubMed
    1. Edelman SM, Kasper DL. 2008. Symbiotic commensal bacteria direct maturation of the host immune system. Curr Opin Gastroenterol 24:720–724. doi:10.1097/MOG.0b013e32830c4355. - DOI - PubMed
    1. Renz H, Brandtzaeg P, Hornef M. 2011. The impact of perinatal immune development on mucosal homeostasis and chronic inflammation. Nat Rev Immunol 12:9–23. doi:10.1038/nrm3028. - DOI - PubMed
    1. Penders J, Thijs C, Vink C, Stelma FF, Snijders B, Kummeling I, van den Brandt PA, Stobberingh EE. 2006. Factors influencing the composition of the intestinal microbiota in early infancy. Pediatrics 118:511–521. doi:10.1542/peds.2005-2824. - DOI - PubMed
    1. Adlerberth I. 2008. Factors influencing the establishment of the intestinal microbiota in infancy. Nestle Nutr Workshop Ser Pediatr Program 62:13–33. doi:10.1159/000146245. - DOI - PubMed

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