The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells
Using quantitative phosphopeptide sequencing of unstimulated versus stimulated primary murine Foxp3(+) regulatory and Foxp3(-) conventional T cells (Tregs and Tconv, respectively), we detected a novel and differentially regulated tyrosine phosphorylation site within the C1 domain of the guanine-nucl...
| Main Authors: | , , , , , , , , , , |
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Akademiai Kiado RT
2017
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| Online Access: | http://hdl.handle.net/1721.1/112185 https://orcid.org/0000-0002-4326-7720 |
| _version_ | 1811082727205634048 |
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| author | Niemz, Jana Kliche, Stefanie Pils, Marina C. Morrison, Eliot Manns, Annika Freund, Christian Galla, Melanie Jänsch, Lothar Huehn, Jochen Crittenden, Jill R Graybiel, Ann M |
| author2 | Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences Niemz, Jana Kliche, Stefanie Pils, Marina C. Morrison, Eliot Manns, Annika Freund, Christian Galla, Melanie Jänsch, Lothar Huehn, Jochen Crittenden, Jill R Graybiel, Ann M |
| author_sort | Niemz, Jana |
| collection | MIT |
| description | Using quantitative phosphopeptide sequencing of unstimulated versus stimulated primary murine Foxp3(+) regulatory and Foxp3(-) conventional T cells (Tregs and Tconv, respectively), we detected a novel and differentially regulated tyrosine phosphorylation site within the C1 domain of the guanine-nucleotide exchange factor CalDAG GEFI. We hypothesized that the Treg-specific and activation-dependent reduced phosphorylation at Y523 allows binding of CalDAG GEFI to diacylglycerol, thereby impacting the formation of a Treg-specific immunological synapse. However, diacylglycerol binding assays of phosphomutant C1 domains of CalDAG GEFI could not confirm this hypothesis. Moreover, CalDAG GEFI(-/-) mice displayed normal Treg numbers in thymus and secondary lymphoid organs, and CalDAG GEFI(-/-) Tregs showed unaltered in vitro suppressive capacity when compared to CalDAG GEFI(+/+) Tregs. Interestingly, when tested in vivo, CalDAG GEFI(-/-) Tregs displayed a slightly reduced suppressive ability in the transfer colitis model when compared to CalDAG GEFI(+/+) Tregs. Additionally, CRISPR-Cas9-generated CalDAG GEFI(-/-) Jurkat T cell clones showed reduced adhesion to ICAM-1 and fibronectin when compared to CalDAG GEFI-competent Jurkat T cells. Therefore, we speculate that deficiency in CalDAG GEFI impairs adherence of Tregs to antigen-presenting cells, thereby impeding formation of a fully functional immunological synapse, which finally results in a reduced suppressive potential. |
| first_indexed | 2024-09-23T12:07:59Z |
| format | Article |
| id | mit-1721.1/112185 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T12:07:59Z |
| publishDate | 2017 |
| publisher | Akademiai Kiado RT |
| record_format | dspace |
| spelling | mit-1721.1/1121852022-09-28T00:22:48Z The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells Niemz, Jana Kliche, Stefanie Pils, Marina C. Morrison, Eliot Manns, Annika Freund, Christian Galla, Melanie Jänsch, Lothar Huehn, Jochen Crittenden, Jill R Graybiel, Ann M Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences McGovern Institute for Brain Research at MIT Crittenden, Jill R Graybiel, Ann M Using quantitative phosphopeptide sequencing of unstimulated versus stimulated primary murine Foxp3(+) regulatory and Foxp3(-) conventional T cells (Tregs and Tconv, respectively), we detected a novel and differentially regulated tyrosine phosphorylation site within the C1 domain of the guanine-nucleotide exchange factor CalDAG GEFI. We hypothesized that the Treg-specific and activation-dependent reduced phosphorylation at Y523 allows binding of CalDAG GEFI to diacylglycerol, thereby impacting the formation of a Treg-specific immunological synapse. However, diacylglycerol binding assays of phosphomutant C1 domains of CalDAG GEFI could not confirm this hypothesis. Moreover, CalDAG GEFI(-/-) mice displayed normal Treg numbers in thymus and secondary lymphoid organs, and CalDAG GEFI(-/-) Tregs showed unaltered in vitro suppressive capacity when compared to CalDAG GEFI(+/+) Tregs. Interestingly, when tested in vivo, CalDAG GEFI(-/-) Tregs displayed a slightly reduced suppressive ability in the transfer colitis model when compared to CalDAG GEFI(+/+) Tregs. Additionally, CRISPR-Cas9-generated CalDAG GEFI(-/-) Jurkat T cell clones showed reduced adhesion to ICAM-1 and fibronectin when compared to CalDAG GEFI-competent Jurkat T cells. Therefore, we speculate that deficiency in CalDAG GEFI impairs adherence of Tregs to antigen-presenting cells, thereby impeding formation of a fully functional immunological synapse, which finally results in a reduced suppressive potential. 2017-11-14T18:44:09Z 2017-11-14T18:44:09Z 2017-05 2017-04 2017-11-09T16:21:31Z Article http://purl.org/eprint/type/JournalArticle 2062-509X 2062-8633 http://hdl.handle.net/1721.1/112185 Niemz, Jana et al. “The Guanine-Nucleotide Exchange Factor CalDAG GEFI Fine-Tunes Functional Properties of Regulatory T Cells.” European Journal of Microbiology and Immunology 7, 2 (June 2017): 112–126 © 2017 The Author(s) https://orcid.org/0000-0002-4326-7720 http://dx.doi.org/10.1556/1886.2017.00007 European Journal of Microbiology and Immunology Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0/ application/pdf Akademiai Kiado RT European Journal of Microbiology and Immunology |
| spellingShingle | Niemz, Jana Kliche, Stefanie Pils, Marina C. Morrison, Eliot Manns, Annika Freund, Christian Galla, Melanie Jänsch, Lothar Huehn, Jochen Crittenden, Jill R Graybiel, Ann M The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells |
| title | The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells |
| title_full | The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells |
| title_fullStr | The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells |
| title_full_unstemmed | The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells |
| title_short | The guanine-nucleotide exchange factor CalDAG GEFI fine-tunes functional properties of regulatory T cells |
| title_sort | guanine nucleotide exchange factor caldag gefi fine tunes functional properties of regulatory t cells |
| url | http://hdl.handle.net/1721.1/112185 https://orcid.org/0000-0002-4326-7720 |
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