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Identification of a genetic locus controlling bacteria-driven colitis and associated cancer through effects on innate inflammation.

Boulard O, Kirchberger S, Royston DJ, Maloy KJ, Powrie FM - J. Exp. Med. (2012)

Bottom Line: Chronic inflammation of the intestine has been associated with an elevated risk of developing colorectal cancer.Using a tumor-promoting model combining chronic Helicobacter hepaticus infection and the carcinogen azoxymethane, we found that Hiccs also regulates the frequency of colitis-associated neoplasia.Our study highlights the importance of innate immune cells and their genetic configuration in driving progression from inflammation toward cancer and opens the door for analysis of these pathways in human inflammatory disorders and associated cancers.

View Article: PubMed Central - HTML - PubMed

Affiliation: Translational Gastroenterology Unit, Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, England, UK.

ABSTRACT
Chronic inflammation of the intestine has been associated with an elevated risk of developing colorectal cancer. Recent association studies have highlighted the role of genetic predisposition in the etiology of colitis and started to unravel its complexity. However, the genetic factors influencing the progression from colon inflammation to tumorigenesis are not known. We report the identification of a genetic interval Hiccs that regulates Helicobacter hepaticus-induced colitis and associated cancer susceptibility in a 129.RAG(-/-) mouse model. The 1.7-Mb congenic interval on chromosome 3, containing eight genes and five microRNAs, renders susceptible mice resistant to colitis and reduces tumor incidence and multiplicity. Bone marrow chimera experiments showed that resistance is conferred by the hematopoietic compartment. Moreover, the Hiccs locus controls the induction of the innate inflammatory response by regulating cytokine expression and granulocyte recruitment by Thy1(+) innate lymphoid cells. Using a tumor-promoting model combining chronic Helicobacter hepaticus infection and the carcinogen azoxymethane, we found that Hiccs also regulates the frequency of colitis-associated neoplasia. Our study highlights the importance of innate immune cells and their genetic configuration in driving progression from inflammation toward cancer and opens the door for analysis of these pathways in human inflammatory disorders and associated cancers.

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The hematopoietic compartment genotype determines protection and susceptibility to H. hepaticus–induced colitis. (A and B) Reciprocal BM chimeras: spleen mass and histological evaluation of colon inflammation after H. hepaticus infection for 8 wk, comparing control and chimeric groups. BM donors and recipients are indicated on the X axis, as donor→recipient: (A) 129 = susceptible 129.RAG mice, C3B = protected 129.C3B.RAG mice; (B) R9 = susceptible R9 mice, R17 = protected R17 mice. Horizontal lines represent medians. **, P < 0.01, Mann-Whitney nonparametric test. (C) Expression of candidate genes within the hematopoietic compartment. Pooled colon LPL from H. hepaticus–infected protected or susceptible mice were FACS sorted into CD45+ and CD45− populations. The expression level of the candidate genes was analyzed using Q-PCR, normalized to Hprt mRNA, and is indicated relative to CD45− protected samples. Mean ± SD of triplicates from a representative experiment out of two independently performed is shown. (D) BMDMs from susceptible R9 and protected R17 mice were generated and stimulated for 20 h with 1 µg/ml LPS or live H. hepaticus (20 MOI). Candidate gene expression levels were analyzed as described and are shown relative to R9 unstimulated cells. Graphs represent mean ± SEM of two pooled independent experiments (n = 4). *, P < 0.05, Mann-Whitney nonparametric test.
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fig6: The hematopoietic compartment genotype determines protection and susceptibility to H. hepaticus–induced colitis. (A and B) Reciprocal BM chimeras: spleen mass and histological evaluation of colon inflammation after H. hepaticus infection for 8 wk, comparing control and chimeric groups. BM donors and recipients are indicated on the X axis, as donor→recipient: (A) 129 = susceptible 129.RAG mice, C3B = protected 129.C3B.RAG mice; (B) R9 = susceptible R9 mice, R17 = protected R17 mice. Horizontal lines represent medians. **, P < 0.01, Mann-Whitney nonparametric test. (C) Expression of candidate genes within the hematopoietic compartment. Pooled colon LPL from H. hepaticus–infected protected or susceptible mice were FACS sorted into CD45+ and CD45− populations. The expression level of the candidate genes was analyzed using Q-PCR, normalized to Hprt mRNA, and is indicated relative to CD45− protected samples. Mean ± SD of triplicates from a representative experiment out of two independently performed is shown. (D) BMDMs from susceptible R9 and protected R17 mice were generated and stimulated for 20 h with 1 µg/ml LPS or live H. hepaticus (20 MOI). Candidate gene expression levels were analyzed as described and are shown relative to R9 unstimulated cells. Graphs represent mean ± SEM of two pooled independent experiments (n = 4). *, P < 0.05, Mann-Whitney nonparametric test.

Mentions: To gain insight into the mechanism of action of Hiccs and to identify the cells involved, reciprocal BM chimeras were generated using 129.RAG and 129.C3B.RAG mice (Fig. 6 A) or using protected (R17) and susceptible (R9) recombinant lines (Fig. 6 B). After reconstitution of the innate immune system by donor BM cells, chimeric mice were infected with H. hepaticus for 8–10 wk. Both approaches clearly illustrated the transfer of phenotype by the hematopoietic compartment. Indeed, susceptible recipients receiving BM from protected donors and infected with H. hepaticus exhibited significantly decreased colonic inflammation and splenomegaly, equivalent to the protected control groups (Fig. 6, A and B). Conversely, R17 or C3B recipients became susceptible to H. hepaticus–induced colitis when reconstituted with BM from R9 or 129.RAG donors, respectively (Fig. 6, A and B). As in previous experiments, inflammation was abrogated in the proximal and distal colon, whereas a reduced inflammatory infiltrate was observed in the mid colon (unpublished data). Severe inflammation of the cecum was observed in all infected chimeras, confirming that the Hiccs locus was not contributing to this phenotype (unpublished data).


Identification of a genetic locus controlling bacteria-driven colitis and associated cancer through effects on innate inflammation.

Boulard O, Kirchberger S, Royston DJ, Maloy KJ, Powrie FM - J. Exp. Med. (2012)

The hematopoietic compartment genotype determines protection and susceptibility to H. hepaticus–induced colitis. (A and B) Reciprocal BM chimeras: spleen mass and histological evaluation of colon inflammation after H. hepaticus infection for 8 wk, comparing control and chimeric groups. BM donors and recipients are indicated on the X axis, as donor→recipient: (A) 129 = susceptible 129.RAG mice, C3B = protected 129.C3B.RAG mice; (B) R9 = susceptible R9 mice, R17 = protected R17 mice. Horizontal lines represent medians. **, P < 0.01, Mann-Whitney nonparametric test. (C) Expression of candidate genes within the hematopoietic compartment. Pooled colon LPL from H. hepaticus–infected protected or susceptible mice were FACS sorted into CD45+ and CD45− populations. The expression level of the candidate genes was analyzed using Q-PCR, normalized to Hprt mRNA, and is indicated relative to CD45− protected samples. Mean ± SD of triplicates from a representative experiment out of two independently performed is shown. (D) BMDMs from susceptible R9 and protected R17 mice were generated and stimulated for 20 h with 1 µg/ml LPS or live H. hepaticus (20 MOI). Candidate gene expression levels were analyzed as described and are shown relative to R9 unstimulated cells. Graphs represent mean ± SEM of two pooled independent experiments (n = 4). *, P < 0.05, Mann-Whitney nonparametric test.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3405508&req=5

fig6: The hematopoietic compartment genotype determines protection and susceptibility to H. hepaticus–induced colitis. (A and B) Reciprocal BM chimeras: spleen mass and histological evaluation of colon inflammation after H. hepaticus infection for 8 wk, comparing control and chimeric groups. BM donors and recipients are indicated on the X axis, as donor→recipient: (A) 129 = susceptible 129.RAG mice, C3B = protected 129.C3B.RAG mice; (B) R9 = susceptible R9 mice, R17 = protected R17 mice. Horizontal lines represent medians. **, P < 0.01, Mann-Whitney nonparametric test. (C) Expression of candidate genes within the hematopoietic compartment. Pooled colon LPL from H. hepaticus–infected protected or susceptible mice were FACS sorted into CD45+ and CD45− populations. The expression level of the candidate genes was analyzed using Q-PCR, normalized to Hprt mRNA, and is indicated relative to CD45− protected samples. Mean ± SD of triplicates from a representative experiment out of two independently performed is shown. (D) BMDMs from susceptible R9 and protected R17 mice were generated and stimulated for 20 h with 1 µg/ml LPS or live H. hepaticus (20 MOI). Candidate gene expression levels were analyzed as described and are shown relative to R9 unstimulated cells. Graphs represent mean ± SEM of two pooled independent experiments (n = 4). *, P < 0.05, Mann-Whitney nonparametric test.
Mentions: To gain insight into the mechanism of action of Hiccs and to identify the cells involved, reciprocal BM chimeras were generated using 129.RAG and 129.C3B.RAG mice (Fig. 6 A) or using protected (R17) and susceptible (R9) recombinant lines (Fig. 6 B). After reconstitution of the innate immune system by donor BM cells, chimeric mice were infected with H. hepaticus for 8–10 wk. Both approaches clearly illustrated the transfer of phenotype by the hematopoietic compartment. Indeed, susceptible recipients receiving BM from protected donors and infected with H. hepaticus exhibited significantly decreased colonic inflammation and splenomegaly, equivalent to the protected control groups (Fig. 6, A and B). Conversely, R17 or C3B recipients became susceptible to H. hepaticus–induced colitis when reconstituted with BM from R9 or 129.RAG donors, respectively (Fig. 6, A and B). As in previous experiments, inflammation was abrogated in the proximal and distal colon, whereas a reduced inflammatory infiltrate was observed in the mid colon (unpublished data). Severe inflammation of the cecum was observed in all infected chimeras, confirming that the Hiccs locus was not contributing to this phenotype (unpublished data).

Bottom Line: Chronic inflammation of the intestine has been associated with an elevated risk of developing colorectal cancer.Using a tumor-promoting model combining chronic Helicobacter hepaticus infection and the carcinogen azoxymethane, we found that Hiccs also regulates the frequency of colitis-associated neoplasia.Our study highlights the importance of innate immune cells and their genetic configuration in driving progression from inflammation toward cancer and opens the door for analysis of these pathways in human inflammatory disorders and associated cancers.

View Article: PubMed Central - HTML - PubMed

Affiliation: Translational Gastroenterology Unit, Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, England, UK.

ABSTRACT
Chronic inflammation of the intestine has been associated with an elevated risk of developing colorectal cancer. Recent association studies have highlighted the role of genetic predisposition in the etiology of colitis and started to unravel its complexity. However, the genetic factors influencing the progression from colon inflammation to tumorigenesis are not known. We report the identification of a genetic interval Hiccs that regulates Helicobacter hepaticus-induced colitis and associated cancer susceptibility in a 129.RAG(-/-) mouse model. The 1.7-Mb congenic interval on chromosome 3, containing eight genes and five microRNAs, renders susceptible mice resistant to colitis and reduces tumor incidence and multiplicity. Bone marrow chimera experiments showed that resistance is conferred by the hematopoietic compartment. Moreover, the Hiccs locus controls the induction of the innate inflammatory response by regulating cytokine expression and granulocyte recruitment by Thy1(+) innate lymphoid cells. Using a tumor-promoting model combining chronic Helicobacter hepaticus infection and the carcinogen azoxymethane, we found that Hiccs also regulates the frequency of colitis-associated neoplasia. Our study highlights the importance of innate immune cells and their genetic configuration in driving progression from inflammation toward cancer and opens the door for analysis of these pathways in human inflammatory disorders and associated cancers.

Show MeSH
Related in: MedlinePlus