Limits...
Conditional Deletion of TAK1 in T Cells Reveals a Pivotal Role of TCRαβ+ Intraepithelial Lymphocytes in Preventing Lymphopenia-Associated Colitis.

Sanjo H, Tokumaru S, Akira S, Taki S - PLoS ONE (2015)

Bottom Line: The kinase TAK is required for the development of conventional and regulatory T cells.Furthermore, the gut microbiota-triggered signaling was also a key event leading to the pathogenesis.Taken together, our current study highlighted the emerging role of TAK1 in configuring the gut-specialized T cell subset, which regulates mucosal homeostasis under lymphopenic conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Immunology, Shinshu University School of Medicine, Nagano, Japan.

ABSTRACT
The kinase TAK is required for the development of conventional and regulatory T cells. We previously reported that mice with conditional deletion of TAK1 in T cells (Lck-cre:TAK1fl/fl mice) exhibited severe T lymphopenia, and were nevertheless predisposed to spontaneous colitis with unknown etiology. Here we focused on the immunopathological mechanism in colitic Lck-cre:TAK1fl/fl mice. We found that 'leaky' CD4+ T cells retaining TAK1 acquired inflammatory phenotypes that contribute to disease onset in Lck-cre:TAK1fl/fl mice. Furthermore, the gut microbiota-triggered signaling was also a key event leading to the pathogenesis. We discovered that Lck-cre:TAK1fl/fl mice were almost completely devoid of TCRαβ+CD8α+ intestinal intraepithelial lymphocytes (IELs) and this was largely due to the developmental defect of the thymic precursors by TAK1 deficiency. Remarkably, transfer of TCRαβ+CD8α+ IELs from wild-type mice ameliorated colitis in Lck-cre:TAK1fl/fl mice. Taken together, our current study highlighted the emerging role of TAK1 in configuring the gut-specialized T cell subset, which regulates mucosal homeostasis under lymphopenic conditions.

No MeSH data available.


Related in: MedlinePlus

TAK1-dependent TCR-driven signaling pathway is essential for the development of TCRαβ+ IELs.(A) Flow cytometry of TCRβ+CD4–CD8–NK1.1– precursor cells in thymus. The plots are representative of at least three independent experiments. (B) Frequency (left) and absolute number (right) of TCRβ+ after gating out of CD4+, CD8+ and NK1.1+ cells of WT (n = 8, filled circle) and LTAC mice (n = 9, open circle), determined by flow cytometry analysis from (A). Horizontal bars represent mean. (C) Characterization of cell surface proteins on TCRβ+ thymic precursor cells after depletion of CD4+, CD8+ and NK1.1+ cells of WT and LTAC mice. The plots are representative of at least three independent experiments. (D, E and F) Thymocytes after depletion of CD4+, CD8+ and NK1.1+ cells were cultured with the plate-bound anti-CD3 antibody (αCD3) in the absence or presence of IL-2 for 3 days. In (D), forward scatter (FSC) for monitoring cell size and inducible expression of CD25 are depicted as histograms. In (E), inducible expression of CD8α on TCRβ+ precursor cells is shown. The plots are representative of at least three independent experiments. In (F), frequency of TCRβ+CD8α+ cells in cultured cells from WT (n = 3, filled bar) and LTAC mice (n = 3, open bar) are shown. Data are shown as mean ± s.e.m.. In (B) and (F), unpaired t tests were performed. Statistical significance was indicated by **P < 0.01, ***P < 0.001, ****P < 0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4489433&req=5

pone.0128761.g006: TAK1-dependent TCR-driven signaling pathway is essential for the development of TCRαβ+ IELs.(A) Flow cytometry of TCRβ+CD4–CD8–NK1.1– precursor cells in thymus. The plots are representative of at least three independent experiments. (B) Frequency (left) and absolute number (right) of TCRβ+ after gating out of CD4+, CD8+ and NK1.1+ cells of WT (n = 8, filled circle) and LTAC mice (n = 9, open circle), determined by flow cytometry analysis from (A). Horizontal bars represent mean. (C) Characterization of cell surface proteins on TCRβ+ thymic precursor cells after depletion of CD4+, CD8+ and NK1.1+ cells of WT and LTAC mice. The plots are representative of at least three independent experiments. (D, E and F) Thymocytes after depletion of CD4+, CD8+ and NK1.1+ cells were cultured with the plate-bound anti-CD3 antibody (αCD3) in the absence or presence of IL-2 for 3 days. In (D), forward scatter (FSC) for monitoring cell size and inducible expression of CD25 are depicted as histograms. In (E), inducible expression of CD8α on TCRβ+ precursor cells is shown. The plots are representative of at least three independent experiments. In (F), frequency of TCRβ+CD8α+ cells in cultured cells from WT (n = 3, filled bar) and LTAC mice (n = 3, open bar) are shown. Data are shown as mean ± s.e.m.. In (B) and (F), unpaired t tests were performed. Statistical significance was indicated by **P < 0.01, ***P < 0.001, ****P < 0.0001.

Mentions: We next sought to determine at which stage the IEL development was impaired in LTAC mice. Since it was shown that IELs developed from thymic precursors [29], we examined thymocytes isolated from LTAC mice for IEL precursors. Flow cytometry analysis showed that thymic IEL precursors, defined as TCRαβ+CD4–CD8–NK1.1–, were significantly decreased in both the frequency and absolute number in LTAC mice when compared with wild-type mice (Fig 6A and 6B). Detailed analysis further demonstrated that such a reduction could be explained by the almost complete loss of CD103-positive cell population coexpressing both CD5 and CD122 (Fig 6C). Additionally, we found that TCRβ+NK1.1+ natural killer T (NKT) cell population in the thymus and liver and α-GalCer/CD1d-reacted NKT cell population in the liver were hardly detectable in LTAC mice (Fig 6A and S2 Fig), indicating that the development of NKT cells is also defective in the absence of TAK1.


Conditional Deletion of TAK1 in T Cells Reveals a Pivotal Role of TCRαβ+ Intraepithelial Lymphocytes in Preventing Lymphopenia-Associated Colitis.

Sanjo H, Tokumaru S, Akira S, Taki S - PLoS ONE (2015)

TAK1-dependent TCR-driven signaling pathway is essential for the development of TCRαβ+ IELs.(A) Flow cytometry of TCRβ+CD4–CD8–NK1.1– precursor cells in thymus. The plots are representative of at least three independent experiments. (B) Frequency (left) and absolute number (right) of TCRβ+ after gating out of CD4+, CD8+ and NK1.1+ cells of WT (n = 8, filled circle) and LTAC mice (n = 9, open circle), determined by flow cytometry analysis from (A). Horizontal bars represent mean. (C) Characterization of cell surface proteins on TCRβ+ thymic precursor cells after depletion of CD4+, CD8+ and NK1.1+ cells of WT and LTAC mice. The plots are representative of at least three independent experiments. (D, E and F) Thymocytes after depletion of CD4+, CD8+ and NK1.1+ cells were cultured with the plate-bound anti-CD3 antibody (αCD3) in the absence or presence of IL-2 for 3 days. In (D), forward scatter (FSC) for monitoring cell size and inducible expression of CD25 are depicted as histograms. In (E), inducible expression of CD8α on TCRβ+ precursor cells is shown. The plots are representative of at least three independent experiments. In (F), frequency of TCRβ+CD8α+ cells in cultured cells from WT (n = 3, filled bar) and LTAC mice (n = 3, open bar) are shown. Data are shown as mean ± s.e.m.. In (B) and (F), unpaired t tests were performed. Statistical significance was indicated by **P < 0.01, ***P < 0.001, ****P < 0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4489433&req=5

pone.0128761.g006: TAK1-dependent TCR-driven signaling pathway is essential for the development of TCRαβ+ IELs.(A) Flow cytometry of TCRβ+CD4–CD8–NK1.1– precursor cells in thymus. The plots are representative of at least three independent experiments. (B) Frequency (left) and absolute number (right) of TCRβ+ after gating out of CD4+, CD8+ and NK1.1+ cells of WT (n = 8, filled circle) and LTAC mice (n = 9, open circle), determined by flow cytometry analysis from (A). Horizontal bars represent mean. (C) Characterization of cell surface proteins on TCRβ+ thymic precursor cells after depletion of CD4+, CD8+ and NK1.1+ cells of WT and LTAC mice. The plots are representative of at least three independent experiments. (D, E and F) Thymocytes after depletion of CD4+, CD8+ and NK1.1+ cells were cultured with the plate-bound anti-CD3 antibody (αCD3) in the absence or presence of IL-2 for 3 days. In (D), forward scatter (FSC) for monitoring cell size and inducible expression of CD25 are depicted as histograms. In (E), inducible expression of CD8α on TCRβ+ precursor cells is shown. The plots are representative of at least three independent experiments. In (F), frequency of TCRβ+CD8α+ cells in cultured cells from WT (n = 3, filled bar) and LTAC mice (n = 3, open bar) are shown. Data are shown as mean ± s.e.m.. In (B) and (F), unpaired t tests were performed. Statistical significance was indicated by **P < 0.01, ***P < 0.001, ****P < 0.0001.
Mentions: We next sought to determine at which stage the IEL development was impaired in LTAC mice. Since it was shown that IELs developed from thymic precursors [29], we examined thymocytes isolated from LTAC mice for IEL precursors. Flow cytometry analysis showed that thymic IEL precursors, defined as TCRαβ+CD4–CD8–NK1.1–, were significantly decreased in both the frequency and absolute number in LTAC mice when compared with wild-type mice (Fig 6A and 6B). Detailed analysis further demonstrated that such a reduction could be explained by the almost complete loss of CD103-positive cell population coexpressing both CD5 and CD122 (Fig 6C). Additionally, we found that TCRβ+NK1.1+ natural killer T (NKT) cell population in the thymus and liver and α-GalCer/CD1d-reacted NKT cell population in the liver were hardly detectable in LTAC mice (Fig 6A and S2 Fig), indicating that the development of NKT cells is also defective in the absence of TAK1.

Bottom Line: The kinase TAK is required for the development of conventional and regulatory T cells.Furthermore, the gut microbiota-triggered signaling was also a key event leading to the pathogenesis.Taken together, our current study highlighted the emerging role of TAK1 in configuring the gut-specialized T cell subset, which regulates mucosal homeostasis under lymphopenic conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Immunology, Shinshu University School of Medicine, Nagano, Japan.

ABSTRACT
The kinase TAK is required for the development of conventional and regulatory T cells. We previously reported that mice with conditional deletion of TAK1 in T cells (Lck-cre:TAK1fl/fl mice) exhibited severe T lymphopenia, and were nevertheless predisposed to spontaneous colitis with unknown etiology. Here we focused on the immunopathological mechanism in colitic Lck-cre:TAK1fl/fl mice. We found that 'leaky' CD4+ T cells retaining TAK1 acquired inflammatory phenotypes that contribute to disease onset in Lck-cre:TAK1fl/fl mice. Furthermore, the gut microbiota-triggered signaling was also a key event leading to the pathogenesis. We discovered that Lck-cre:TAK1fl/fl mice were almost completely devoid of TCRαβ+CD8α+ intestinal intraepithelial lymphocytes (IELs) and this was largely due to the developmental defect of the thymic precursors by TAK1 deficiency. Remarkably, transfer of TCRαβ+CD8α+ IELs from wild-type mice ameliorated colitis in Lck-cre:TAK1fl/fl mice. Taken together, our current study highlighted the emerging role of TAK1 in configuring the gut-specialized T cell subset, which regulates mucosal homeostasis under lymphopenic conditions.

No MeSH data available.


Related in: MedlinePlus