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DNA Repair Cofactors ATMIN and NBS1 Are Required to Suppress T Cell Activation.

Prochazkova J, Sakaguchi S, Owusu M, Mazouzi A, Wiedner M, Velimezi G, Moder M, Turchinovich G, Hladik A, Gurnhofer E, Hayday A, Behrens A, Knapp S, Kenner L, Ellmeier W, Loizou JI - PLoS Genet. (2015)

Bottom Line: We show loss of NBS1 led to a developmental block at the double-positive stage of T cell development, as well as reduced TCRα recombination, that was unexpectedly neither exacerbated nor alleviated by concomitant loss of ATMIN.In vivo this resulted in severe intestinal inflammation, colitis and premature death.Our findings reveal a novel model for an intestinal bowel disease phenotype that occurs upon combined loss of the DNA repair cofactors ATMIN and NBS1.

View Article: PubMed Central - PubMed

Affiliation: CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.

ABSTRACT
Proper development of the immune system is an intricate process dependent on many factors, including an intact DNA damage response. The DNA double-strand break signaling kinase ATM and its cofactor NBS1 are required during T cell development and for the maintenance of genomic stability. The role of a second ATM cofactor, ATMIN (also known as ASCIZ) in T cells is much less clear, and whether ATMIN and NBS1 function in synergy in T cells is unknown. Here, we investigate the roles of ATMIN and NBS1, either alone or in combination, using murine models. We show loss of NBS1 led to a developmental block at the double-positive stage of T cell development, as well as reduced TCRα recombination, that was unexpectedly neither exacerbated nor alleviated by concomitant loss of ATMIN. In contrast, loss of both ATMIN and NBS1 enhanced DNA damage that drove spontaneous peripheral T cell hyperactivation, proliferation as well as excessive production of proinflammatory cytokines and chemokines, leading to a highly inflammatory environment. Intriguingly, the disease causing T cells were largely proficient for both ATMIN and NBS1. In vivo this resulted in severe intestinal inflammation, colitis and premature death. Our findings reveal a novel model for an intestinal bowel disease phenotype that occurs upon combined loss of the DNA repair cofactors ATMIN and NBS1.

No MeSH data available.


Related in: MedlinePlus

Loss of ATMIN in combination with NBS1, in T cells, leads to increased mortality due to T cell activation.(A) Kaplan-Meier survival curve of control, ATMINΔL, NBS1ΔL, ATMINΔLNBS1ΔL and ATM-/- mice. Survival was monitored for 32 weeks. (B) Representative images of spleens of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice as well as a moribund ATMINΔLNBS1ΔL mouse. (C) Histological analysis of the spleen of a control and a moribund ATMINΔLNBS1ΔL mouse stained for T cells using an anti-CD3 antibody. (D) Representative flow cytometry data of CD4 and CD8 T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (E) Histological analysis by using an anti-CD3 antibody to visualize T cells in the liver and lung of control and ATMINΔLNBS1ΔL mice. (F) Representative flow cytometry data of activated CD62LlowCD44+ T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (G) Quantification of F. N = 3–4 mice per genotype. (H) Flow cytometry data showing the percentage of antigen-experienced CD62LlowCD4+ T cells (gated on the TCRβ+ population) in the spleen of control and ATMINΔLNBS1ΔL mice as well as moribund ATMINΔLNBS1ΔL mice. (I) Representative flow cytometry data of proliferating (BrdU+) T cells (gated on the TCRβ+ population) in the spleen of mice indicated in F, measured by in vivo BrdU incorporation over a period of 4 days. (J) Quantification of I. N = 3–4 mice per genotype. Error bars represent SEM (*P<0.05, ***P<0.001).
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pgen.1005645.g002: Loss of ATMIN in combination with NBS1, in T cells, leads to increased mortality due to T cell activation.(A) Kaplan-Meier survival curve of control, ATMINΔL, NBS1ΔL, ATMINΔLNBS1ΔL and ATM-/- mice. Survival was monitored for 32 weeks. (B) Representative images of spleens of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice as well as a moribund ATMINΔLNBS1ΔL mouse. (C) Histological analysis of the spleen of a control and a moribund ATMINΔLNBS1ΔL mouse stained for T cells using an anti-CD3 antibody. (D) Representative flow cytometry data of CD4 and CD8 T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (E) Histological analysis by using an anti-CD3 antibody to visualize T cells in the liver and lung of control and ATMINΔLNBS1ΔL mice. (F) Representative flow cytometry data of activated CD62LlowCD44+ T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (G) Quantification of F. N = 3–4 mice per genotype. (H) Flow cytometry data showing the percentage of antigen-experienced CD62LlowCD4+ T cells (gated on the TCRβ+ population) in the spleen of control and ATMINΔLNBS1ΔL mice as well as moribund ATMINΔLNBS1ΔL mice. (I) Representative flow cytometry data of proliferating (BrdU+) T cells (gated on the TCRβ+ population) in the spleen of mice indicated in F, measured by in vivo BrdU incorporation over a period of 4 days. (J) Quantification of I. N = 3–4 mice per genotype. Error bars represent SEM (*P<0.05, ***P<0.001).

Mentions: ATMINΔLNBS1ΔL mice but not ATMINΔL or NBS1ΔL mice display increased mortality (Fig 2A). Whereas ATM-/- mice developed thymic lymphomas, the compound mutant mice developed splenomegaly marked by an accumulation of CD3+ cells (Fig 2B and 2C) that were of a CD4+ subtype (Fig 2D). The CD8+ T cells were decreased (Fig 2D). An infiltration of CD3+ T cells was observed in multiple organs, including the liver and lungs of moribund ATMINΔLNBS1ΔL mice (Fig 2E).


DNA Repair Cofactors ATMIN and NBS1 Are Required to Suppress T Cell Activation.

Prochazkova J, Sakaguchi S, Owusu M, Mazouzi A, Wiedner M, Velimezi G, Moder M, Turchinovich G, Hladik A, Gurnhofer E, Hayday A, Behrens A, Knapp S, Kenner L, Ellmeier W, Loizou JI - PLoS Genet. (2015)

Loss of ATMIN in combination with NBS1, in T cells, leads to increased mortality due to T cell activation.(A) Kaplan-Meier survival curve of control, ATMINΔL, NBS1ΔL, ATMINΔLNBS1ΔL and ATM-/- mice. Survival was monitored for 32 weeks. (B) Representative images of spleens of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice as well as a moribund ATMINΔLNBS1ΔL mouse. (C) Histological analysis of the spleen of a control and a moribund ATMINΔLNBS1ΔL mouse stained for T cells using an anti-CD3 antibody. (D) Representative flow cytometry data of CD4 and CD8 T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (E) Histological analysis by using an anti-CD3 antibody to visualize T cells in the liver and lung of control and ATMINΔLNBS1ΔL mice. (F) Representative flow cytometry data of activated CD62LlowCD44+ T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (G) Quantification of F. N = 3–4 mice per genotype. (H) Flow cytometry data showing the percentage of antigen-experienced CD62LlowCD4+ T cells (gated on the TCRβ+ population) in the spleen of control and ATMINΔLNBS1ΔL mice as well as moribund ATMINΔLNBS1ΔL mice. (I) Representative flow cytometry data of proliferating (BrdU+) T cells (gated on the TCRβ+ population) in the spleen of mice indicated in F, measured by in vivo BrdU incorporation over a period of 4 days. (J) Quantification of I. N = 3–4 mice per genotype. Error bars represent SEM (*P<0.05, ***P<0.001).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4636180&req=5

pgen.1005645.g002: Loss of ATMIN in combination with NBS1, in T cells, leads to increased mortality due to T cell activation.(A) Kaplan-Meier survival curve of control, ATMINΔL, NBS1ΔL, ATMINΔLNBS1ΔL and ATM-/- mice. Survival was monitored for 32 weeks. (B) Representative images of spleens of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice as well as a moribund ATMINΔLNBS1ΔL mouse. (C) Histological analysis of the spleen of a control and a moribund ATMINΔLNBS1ΔL mouse stained for T cells using an anti-CD3 antibody. (D) Representative flow cytometry data of CD4 and CD8 T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (E) Histological analysis by using an anti-CD3 antibody to visualize T cells in the liver and lung of control and ATMINΔLNBS1ΔL mice. (F) Representative flow cytometry data of activated CD62LlowCD44+ T cells (gated on the TCRβ+ population) in the spleen of control, ATMINΔL, NBS1ΔL and ATMINΔLNBS1ΔL mice. (G) Quantification of F. N = 3–4 mice per genotype. (H) Flow cytometry data showing the percentage of antigen-experienced CD62LlowCD4+ T cells (gated on the TCRβ+ population) in the spleen of control and ATMINΔLNBS1ΔL mice as well as moribund ATMINΔLNBS1ΔL mice. (I) Representative flow cytometry data of proliferating (BrdU+) T cells (gated on the TCRβ+ population) in the spleen of mice indicated in F, measured by in vivo BrdU incorporation over a period of 4 days. (J) Quantification of I. N = 3–4 mice per genotype. Error bars represent SEM (*P<0.05, ***P<0.001).
Mentions: ATMINΔLNBS1ΔL mice but not ATMINΔL or NBS1ΔL mice display increased mortality (Fig 2A). Whereas ATM-/- mice developed thymic lymphomas, the compound mutant mice developed splenomegaly marked by an accumulation of CD3+ cells (Fig 2B and 2C) that were of a CD4+ subtype (Fig 2D). The CD8+ T cells were decreased (Fig 2D). An infiltration of CD3+ T cells was observed in multiple organs, including the liver and lungs of moribund ATMINΔLNBS1ΔL mice (Fig 2E).

Bottom Line: We show loss of NBS1 led to a developmental block at the double-positive stage of T cell development, as well as reduced TCRα recombination, that was unexpectedly neither exacerbated nor alleviated by concomitant loss of ATMIN.In vivo this resulted in severe intestinal inflammation, colitis and premature death.Our findings reveal a novel model for an intestinal bowel disease phenotype that occurs upon combined loss of the DNA repair cofactors ATMIN and NBS1.

View Article: PubMed Central - PubMed

Affiliation: CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.

ABSTRACT
Proper development of the immune system is an intricate process dependent on many factors, including an intact DNA damage response. The DNA double-strand break signaling kinase ATM and its cofactor NBS1 are required during T cell development and for the maintenance of genomic stability. The role of a second ATM cofactor, ATMIN (also known as ASCIZ) in T cells is much less clear, and whether ATMIN and NBS1 function in synergy in T cells is unknown. Here, we investigate the roles of ATMIN and NBS1, either alone or in combination, using murine models. We show loss of NBS1 led to a developmental block at the double-positive stage of T cell development, as well as reduced TCRα recombination, that was unexpectedly neither exacerbated nor alleviated by concomitant loss of ATMIN. In contrast, loss of both ATMIN and NBS1 enhanced DNA damage that drove spontaneous peripheral T cell hyperactivation, proliferation as well as excessive production of proinflammatory cytokines and chemokines, leading to a highly inflammatory environment. Intriguingly, the disease causing T cells were largely proficient for both ATMIN and NBS1. In vivo this resulted in severe intestinal inflammation, colitis and premature death. Our findings reveal a novel model for an intestinal bowel disease phenotype that occurs upon combined loss of the DNA repair cofactors ATMIN and NBS1.

No MeSH data available.


Related in: MedlinePlus