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Genetic dissection of the cellular pathways and signaling mechanisms in modeled tumor necrosis factor-induced Crohn's-like inflammatory bowel disease.

Kontoyiannis D, Boulougouris G, Manoloukos M, Armaka M, Apostolaki M, Pizarro T, Kotlyarov A, Forster I, Flavell R, Gaestel M, Tsichlis P, Cominelli F, Kollias G - J. Exp. Med. (2002)

Bottom Line: Tissue-specific activation of the mutant TNF allele by Cre/loxP-mediated recombination indicated that either myeloid- or T cell-derived TNF can exhibit full pathogenic capacity.Interestingly, TNF-mediated intestinal pathology was exacerbated in the absence of MAPKAP kinase 2, yet strongly attenuated in a Cot/Tpl2 or JNK2 kinase-deficient genetic background.Our data establish the existence of redundant cellular pathways operating downstream of TNF in inflammatory bowel disease, and demonstrate the therapeutic potential of selective kinase blockade in TNF-mediated intestinal pathology.

View Article: PubMed Central - PubMed

Affiliation: Institute for Immunology, Biomedical Sciences Research Center "Al. Fleming," Vari 166-72, Greece. Division of Gastroenterology and Hepatology, University of Virginia Health Sciences Center, Charlottesville, VA 22906, USA.

ABSTRACT
Recent clinical evidence demonstrated the importance of tumor necrosis factor (TNF) in the development of Crohn's disease. A mouse model for this pathology has previously been established by engineering defects in the translational control of TNF mRNA (Tnf(Delta)(ARE) mouse). Here, we show that development of intestinal pathology in this model depends on Th1-like cytokines such as interleukin 12 and interferon gamma and requires the function of CD8(+) T lymphocytes. Tissue-specific activation of the mutant TNF allele by Cre/loxP-mediated recombination indicated that either myeloid- or T cell-derived TNF can exhibit full pathogenic capacity. Moreover, reciprocal bone marrow transplantation experiments using TNF receptor-deficient mice revealed that TNF signals are equally pathogenic when directed independently to either bone marrow-derived or tissue stroma cell targets. Interestingly, TNF-mediated intestinal pathology was exacerbated in the absence of MAPKAP kinase 2, yet strongly attenuated in a Cot/Tpl2 or JNK2 kinase-deficient genetic background. Our data establish the existence of redundant cellular pathways operating downstream of TNF in inflammatory bowel disease, and demonstrate the therapeutic potential of selective kinase blockade in TNF-mediated intestinal pathology.

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CTL activity of TnfΔAREsplenocytes in response to syngeneic stimulation. CTL assay on the syngeneic epithelial cell line CMT-93. Mitomycin C–treated, 3[H]thymidine-pulsed CMT-93 target (T) cells were cocultured with increasing numbers of wild-type (left) and TnfΔARE/+ effector (right) in the presence or absence of anti-CD3 (2C11) or anti-TNF antibody (TN3). 3[H] label loss indicates target cell lysis.
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fig2: CTL activity of TnfΔAREsplenocytes in response to syngeneic stimulation. CTL assay on the syngeneic epithelial cell line CMT-93. Mitomycin C–treated, 3[H]thymidine-pulsed CMT-93 target (T) cells were cocultured with increasing numbers of wild-type (left) and TnfΔARE/+ effector (right) in the presence or absence of anti-CD3 (2C11) or anti-TNF antibody (TN3). 3[H] label loss indicates target cell lysis.

Mentions: Examination of the CTL effector activity in TnfΔARE/+ cultures from inflamed animals by means of measuring the ability of TnfΔARE/+ splenocytes to lyse syngeneic (H-2b) CMT-93 cell targets in vitro, revealed that TnfΔAREsplenocytes exhibited a high degree of target cell lysis at E/T ratios as low as 10 (Fig. 2 B). Interestingly, the observed target cytolysis was not mediated by TNF because it could not be blocked by anti-TNF antibody treatment (Fig. 2 B). When examined in allogeneic (BALB/c, H-2d) MLRs, TnfΔARE/+ splenocytes (H-2b) from 4-wk-old, disease-free animals showed significantly enhanced proliferation compared to Tnf+/+ controls, even at low doses of alloantigen (not depicted). The apparent hyperproliferation of TnfΔARE/+ splenocytes in the MLRs correlated with a stimulus-dependent twofold increase in the number of activated CD8+ but not CD4+ T cells (not depicted). Taken together, these data indicate that chronic overproduction of TNF in TnfΔARE mice results in the selective accumulation of activated/memory CD8+ T cell subsets. This accumulation correlates with an increased reactivity to allogeneic and syngeneic targets, and may therefore bear direct pathogenic significance in the development of IBD.


Genetic dissection of the cellular pathways and signaling mechanisms in modeled tumor necrosis factor-induced Crohn's-like inflammatory bowel disease.

Kontoyiannis D, Boulougouris G, Manoloukos M, Armaka M, Apostolaki M, Pizarro T, Kotlyarov A, Forster I, Flavell R, Gaestel M, Tsichlis P, Cominelli F, Kollias G - J. Exp. Med. (2002)

CTL activity of TnfΔAREsplenocytes in response to syngeneic stimulation. CTL assay on the syngeneic epithelial cell line CMT-93. Mitomycin C–treated, 3[H]thymidine-pulsed CMT-93 target (T) cells were cocultured with increasing numbers of wild-type (left) and TnfΔARE/+ effector (right) in the presence or absence of anti-CD3 (2C11) or anti-TNF antibody (TN3). 3[H] label loss indicates target cell lysis.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196068&req=5

fig2: CTL activity of TnfΔAREsplenocytes in response to syngeneic stimulation. CTL assay on the syngeneic epithelial cell line CMT-93. Mitomycin C–treated, 3[H]thymidine-pulsed CMT-93 target (T) cells were cocultured with increasing numbers of wild-type (left) and TnfΔARE/+ effector (right) in the presence or absence of anti-CD3 (2C11) or anti-TNF antibody (TN3). 3[H] label loss indicates target cell lysis.
Mentions: Examination of the CTL effector activity in TnfΔARE/+ cultures from inflamed animals by means of measuring the ability of TnfΔARE/+ splenocytes to lyse syngeneic (H-2b) CMT-93 cell targets in vitro, revealed that TnfΔAREsplenocytes exhibited a high degree of target cell lysis at E/T ratios as low as 10 (Fig. 2 B). Interestingly, the observed target cytolysis was not mediated by TNF because it could not be blocked by anti-TNF antibody treatment (Fig. 2 B). When examined in allogeneic (BALB/c, H-2d) MLRs, TnfΔARE/+ splenocytes (H-2b) from 4-wk-old, disease-free animals showed significantly enhanced proliferation compared to Tnf+/+ controls, even at low doses of alloantigen (not depicted). The apparent hyperproliferation of TnfΔARE/+ splenocytes in the MLRs correlated with a stimulus-dependent twofold increase in the number of activated CD8+ but not CD4+ T cells (not depicted). Taken together, these data indicate that chronic overproduction of TNF in TnfΔARE mice results in the selective accumulation of activated/memory CD8+ T cell subsets. This accumulation correlates with an increased reactivity to allogeneic and syngeneic targets, and may therefore bear direct pathogenic significance in the development of IBD.

Bottom Line: Tissue-specific activation of the mutant TNF allele by Cre/loxP-mediated recombination indicated that either myeloid- or T cell-derived TNF can exhibit full pathogenic capacity.Interestingly, TNF-mediated intestinal pathology was exacerbated in the absence of MAPKAP kinase 2, yet strongly attenuated in a Cot/Tpl2 or JNK2 kinase-deficient genetic background.Our data establish the existence of redundant cellular pathways operating downstream of TNF in inflammatory bowel disease, and demonstrate the therapeutic potential of selective kinase blockade in TNF-mediated intestinal pathology.

View Article: PubMed Central - PubMed

Affiliation: Institute for Immunology, Biomedical Sciences Research Center "Al. Fleming," Vari 166-72, Greece. Division of Gastroenterology and Hepatology, University of Virginia Health Sciences Center, Charlottesville, VA 22906, USA.

ABSTRACT
Recent clinical evidence demonstrated the importance of tumor necrosis factor (TNF) in the development of Crohn's disease. A mouse model for this pathology has previously been established by engineering defects in the translational control of TNF mRNA (Tnf(Delta)(ARE) mouse). Here, we show that development of intestinal pathology in this model depends on Th1-like cytokines such as interleukin 12 and interferon gamma and requires the function of CD8(+) T lymphocytes. Tissue-specific activation of the mutant TNF allele by Cre/loxP-mediated recombination indicated that either myeloid- or T cell-derived TNF can exhibit full pathogenic capacity. Moreover, reciprocal bone marrow transplantation experiments using TNF receptor-deficient mice revealed that TNF signals are equally pathogenic when directed independently to either bone marrow-derived or tissue stroma cell targets. Interestingly, TNF-mediated intestinal pathology was exacerbated in the absence of MAPKAP kinase 2, yet strongly attenuated in a Cot/Tpl2 or JNK2 kinase-deficient genetic background. Our data establish the existence of redundant cellular pathways operating downstream of TNF in inflammatory bowel disease, and demonstrate the therapeutic potential of selective kinase blockade in TNF-mediated intestinal pathology.

Show MeSH
Related in: MedlinePlus