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Autoimmune pancreatitis results from loss of TGFbeta signalling in S100A4-positive dendritic cells.

Boomershine CS, Chamberlain A, Kendall P, Afshar-Sharif AR, Huang H, Washington MK, Lawson WE, Thomas JW, Blackwell TS, Bhowmick NA - Gut (2009)

Bottom Line: DCs were confirmed to express S100A4, a previously reported protein expressed by fibroblasts.Tgfbr2(fspKO) DCs undergo elevated maturation in response to antigen and increased activation of naïve CD4-positive T cells.The loss of immune tolerance in myeloid S100A4(+) DCs can mediate mAIP and may explain some aspects of AIP disease pathogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Vanderbilt-Ingram Cancer, Vanderbilt University, Nashville 37232, Tennessee, USA.

ABSTRACT

Background and aims: Autoimmune pancreatitis (AIP) is a poorly understood human disease affecting the exocrine pancreas. The goal of the present study was to elucidate the pathogenic mechanisms underlying pancreatic autoimmunity in a murine disease model.

Methods: A transgenic mouse with an S100A4/fibroblast-specific protein 1 (FSP1) Cre-mediated conditional knockout of the transforming growth factor beta (TGFbeta) type II receptor, termed Tgfbr2(fspKO), was used to determine the direct role of TGFbeta in S100A4(+) cells. Immunohistochemical studies suggested that Tgfbr2(fspKO) mice develop mouse AIP (mAIP) characterised by interlobular ductal inflammatory infiltrates and pancreatic autoantibody production. Fluorescence-activated cell sorting (FACS)-isolated dendritic cells (DCs) from diseased pancreata were verified to have S100A4-Cre-mediated DNA recombination.

Results: The Tgfbr2(fspKO) mice spontaneously developed mAIP by 6 weeks of age. DCs were confirmed to express S100A4, a previously reported protein expressed by fibroblasts. Adoptive transfer of bone marrow-derived DCs from Tgfbr2(fspKO) mice into 2-week-old syngenic wild-type C57BL/6 mice resulted in reproduction of pancreatitis within 6 weeks. Similar adoptive transfer of wild-type DCs had no effect on pancreas pathology of the host mice. The inability to induce pancreatitis by adoptive transfer of Tgfbr2(fspKO) DCs in adult mice suggested a developmental event in mAIP pathogenesis. Tgfbr2(fspKO) DCs undergo elevated maturation in response to antigen and increased activation of naïve CD4-positive T cells.

Conclusion: The development of mAIP in the Tgfbr2(fspKO) mouse model illustrates the role of TGFbeta in maintaining myeloid DC immune tolerance. The loss of immune tolerance in myeloid S100A4(+) DCs can mediate mAIP and may explain some aspects of AIP disease pathogenesis.

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Tgfbr2fspKO dendritic cells (DCs) can induce autoimmune pancreatitis. Representative H&E-stained pancreatic tissue from 2-week-old wild-type mice after transfer of bone marrow-derived DCs from (A) Tgfbr2floxE2/floxE2 control or (B) Tgfbr2fspKO mice (n = 12). Arrows indicate areas of inflammation. (C) Fluorescence-activated cell sorting (FACS) analysis of 1×106 live bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice before and after treatment with lipopolysaccharide (LPS) for 24 h to determine the percentage of mature DCs defined as live DCs simultaneously expressing CD11c and high levels of CD86 and major histocompatibility complex (MHC) class II. No significant difference was seen between untreated DCs, but LPS stimulation induced a significantly higher percentage of mature DCs in Tgfbr2fspKO cultures (p = 0.002). (D) Proliferation of OTII.1 CD4+ T cells stimulated with ovalbumin-pulsed bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice. Tgfbr2fspKO DCs induced significantly higher T cell proliferation with increasing DC number (p = 0.05, untreated T cell control 335 (119) cpm).
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gut-58-09-1267-f08: Tgfbr2fspKO dendritic cells (DCs) can induce autoimmune pancreatitis. Representative H&E-stained pancreatic tissue from 2-week-old wild-type mice after transfer of bone marrow-derived DCs from (A) Tgfbr2floxE2/floxE2 control or (B) Tgfbr2fspKO mice (n = 12). Arrows indicate areas of inflammation. (C) Fluorescence-activated cell sorting (FACS) analysis of 1×106 live bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice before and after treatment with lipopolysaccharide (LPS) for 24 h to determine the percentage of mature DCs defined as live DCs simultaneously expressing CD11c and high levels of CD86 and major histocompatibility complex (MHC) class II. No significant difference was seen between untreated DCs, but LPS stimulation induced a significantly higher percentage of mature DCs in Tgfbr2fspKO cultures (p = 0.002). (D) Proliferation of OTII.1 CD4+ T cells stimulated with ovalbumin-pulsed bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice. Tgfbr2fspKO DCs induced significantly higher T cell proliferation with increasing DC number (p = 0.05, untreated T cell control 335 (119) cpm).

Mentions: To implicate S100A4+ DCs directly in the pathogenesis of mAIP, bone marrow-derived DCs generated from either Tgfbr2fspKO or Tgfbr2floxE2/floxE2 control mice were transferred by intraperitoneal injection to two groups of 2-week-old syngeneic, wild-type mice. After 6 weeks, pancreata from all mice were harvested and examined for evidence of inflammation. Histologically, all mice receiving Tgfbr2fspKO DCs showed pancreatic inflammatory infiltrates, but mice receiving Tgfbr2floxE2/floxE2 DCs failed to develop pancreatitis (fig 8A,B). Development of pancreatitis was age dependent, as adult mice receiving either Tgfbr2fspKO or Tgfbr2floxE2/floxE2 DCs failed to develop pancreatitis under similar conditions (data not shown). Development of pancreatitis in Tgfbr2fspKO DC chimeras indicated that TGFβ signalling in S100A4-positive myeloid DCs is required to prevent development of mAIP and supports a role for TGFβ signalling in DC-mediated immune tolerance. The finding that development of pancreatitis was age dependent implicated an early pancreatic developmental event in mAIP pathogenesis.


Autoimmune pancreatitis results from loss of TGFbeta signalling in S100A4-positive dendritic cells.

Boomershine CS, Chamberlain A, Kendall P, Afshar-Sharif AR, Huang H, Washington MK, Lawson WE, Thomas JW, Blackwell TS, Bhowmick NA - Gut (2009)

Tgfbr2fspKO dendritic cells (DCs) can induce autoimmune pancreatitis. Representative H&E-stained pancreatic tissue from 2-week-old wild-type mice after transfer of bone marrow-derived DCs from (A) Tgfbr2floxE2/floxE2 control or (B) Tgfbr2fspKO mice (n = 12). Arrows indicate areas of inflammation. (C) Fluorescence-activated cell sorting (FACS) analysis of 1×106 live bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice before and after treatment with lipopolysaccharide (LPS) for 24 h to determine the percentage of mature DCs defined as live DCs simultaneously expressing CD11c and high levels of CD86 and major histocompatibility complex (MHC) class II. No significant difference was seen between untreated DCs, but LPS stimulation induced a significantly higher percentage of mature DCs in Tgfbr2fspKO cultures (p = 0.002). (D) Proliferation of OTII.1 CD4+ T cells stimulated with ovalbumin-pulsed bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice. Tgfbr2fspKO DCs induced significantly higher T cell proliferation with increasing DC number (p = 0.05, untreated T cell control 335 (119) cpm).
© Copyright Policy - openaccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2719085&req=5

gut-58-09-1267-f08: Tgfbr2fspKO dendritic cells (DCs) can induce autoimmune pancreatitis. Representative H&E-stained pancreatic tissue from 2-week-old wild-type mice after transfer of bone marrow-derived DCs from (A) Tgfbr2floxE2/floxE2 control or (B) Tgfbr2fspKO mice (n = 12). Arrows indicate areas of inflammation. (C) Fluorescence-activated cell sorting (FACS) analysis of 1×106 live bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice before and after treatment with lipopolysaccharide (LPS) for 24 h to determine the percentage of mature DCs defined as live DCs simultaneously expressing CD11c and high levels of CD86 and major histocompatibility complex (MHC) class II. No significant difference was seen between untreated DCs, but LPS stimulation induced a significantly higher percentage of mature DCs in Tgfbr2fspKO cultures (p = 0.002). (D) Proliferation of OTII.1 CD4+ T cells stimulated with ovalbumin-pulsed bone marrow-derived DCs from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice. Tgfbr2fspKO DCs induced significantly higher T cell proliferation with increasing DC number (p = 0.05, untreated T cell control 335 (119) cpm).
Mentions: To implicate S100A4+ DCs directly in the pathogenesis of mAIP, bone marrow-derived DCs generated from either Tgfbr2fspKO or Tgfbr2floxE2/floxE2 control mice were transferred by intraperitoneal injection to two groups of 2-week-old syngeneic, wild-type mice. After 6 weeks, pancreata from all mice were harvested and examined for evidence of inflammation. Histologically, all mice receiving Tgfbr2fspKO DCs showed pancreatic inflammatory infiltrates, but mice receiving Tgfbr2floxE2/floxE2 DCs failed to develop pancreatitis (fig 8A,B). Development of pancreatitis was age dependent, as adult mice receiving either Tgfbr2fspKO or Tgfbr2floxE2/floxE2 DCs failed to develop pancreatitis under similar conditions (data not shown). Development of pancreatitis in Tgfbr2fspKO DC chimeras indicated that TGFβ signalling in S100A4-positive myeloid DCs is required to prevent development of mAIP and supports a role for TGFβ signalling in DC-mediated immune tolerance. The finding that development of pancreatitis was age dependent implicated an early pancreatic developmental event in mAIP pathogenesis.

Bottom Line: DCs were confirmed to express S100A4, a previously reported protein expressed by fibroblasts.Tgfbr2(fspKO) DCs undergo elevated maturation in response to antigen and increased activation of naïve CD4-positive T cells.The loss of immune tolerance in myeloid S100A4(+) DCs can mediate mAIP and may explain some aspects of AIP disease pathogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Vanderbilt-Ingram Cancer, Vanderbilt University, Nashville 37232, Tennessee, USA.

ABSTRACT

Background and aims: Autoimmune pancreatitis (AIP) is a poorly understood human disease affecting the exocrine pancreas. The goal of the present study was to elucidate the pathogenic mechanisms underlying pancreatic autoimmunity in a murine disease model.

Methods: A transgenic mouse with an S100A4/fibroblast-specific protein 1 (FSP1) Cre-mediated conditional knockout of the transforming growth factor beta (TGFbeta) type II receptor, termed Tgfbr2(fspKO), was used to determine the direct role of TGFbeta in S100A4(+) cells. Immunohistochemical studies suggested that Tgfbr2(fspKO) mice develop mouse AIP (mAIP) characterised by interlobular ductal inflammatory infiltrates and pancreatic autoantibody production. Fluorescence-activated cell sorting (FACS)-isolated dendritic cells (DCs) from diseased pancreata were verified to have S100A4-Cre-mediated DNA recombination.

Results: The Tgfbr2(fspKO) mice spontaneously developed mAIP by 6 weeks of age. DCs were confirmed to express S100A4, a previously reported protein expressed by fibroblasts. Adoptive transfer of bone marrow-derived DCs from Tgfbr2(fspKO) mice into 2-week-old syngenic wild-type C57BL/6 mice resulted in reproduction of pancreatitis within 6 weeks. Similar adoptive transfer of wild-type DCs had no effect on pancreas pathology of the host mice. The inability to induce pancreatitis by adoptive transfer of Tgfbr2(fspKO) DCs in adult mice suggested a developmental event in mAIP pathogenesis. Tgfbr2(fspKO) DCs undergo elevated maturation in response to antigen and increased activation of naïve CD4-positive T cells.

Conclusion: The development of mAIP in the Tgfbr2(fspKO) mouse model illustrates the role of TGFbeta in maintaining myeloid DC immune tolerance. The loss of immune tolerance in myeloid S100A4(+) DCs can mediate mAIP and may explain some aspects of AIP disease pathogenesis.

Show MeSH
Related in: MedlinePlus