1
|
Chen XL, Serrano D, Mayhue M, Hoebe K, Ilangumaran S, Ramanathan S. GIMAP5 Deficiency Is Associated with Increased AKT Activity in T Lymphocytes. PLoS One 2015; 10:e0139019. [PMID: 26440416 PMCID: PMC4595448 DOI: 10.1371/journal.pone.0139019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/07/2015] [Indexed: 01/05/2023] Open
Abstract
Long-term survival of T lymphocytes in quiescent state is essential to maintain their cell numbers in secondary lymphoid organs. In mice and in rats, the loss of functional GTPase of the immune associated nucleotide binding protein 5 (GIMAP5) causes peripheral T lymphopenia due to spontaneous death of T cells. The underlying mechanism responsible for the disruption of quiescence in Gimap5 deficient T cells remains largely unknown. In this study, we show that loss of functional Gimap5 results in increased basal activation of mammalian target of rapamycin (mTOR), independent of protein phosphatase 2A (PP2A) or AMP-activated protein kinase (AMPK). Our results suggest that the constitutive activation of the phosphoinositide 3-kinase (PI3K) pathway may be one of the consequences of the absence of functional GIMAP5.
Collapse
Affiliation(s)
- Xi-Lin Chen
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Daniel Serrano
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Marian Mayhue
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Kasper Hoebe
- Department of Pediatrics, Division of Cellular and Molecular Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States of America
| | - Subburaj Ilangumaran
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- Centre de Recherche Clinique, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| | - Sheela Ramanathan
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- Centre de Recherche Clinique, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
- * E-mail:
| |
Collapse
|
2
|
Heinonen MT, Laine AP, Söderhäll C, Gruzieva O, Rautio S, Melén E, Pershagen G, Lähdesmäki HJ, Knip M, Ilonen J, Henttinen TA, Kere J, Lahesmaa R. GIMAP GTPase family genes: potential modifiers in autoimmune diabetes, asthma, and allergy. THE JOURNAL OF IMMUNOLOGY 2015; 194:5885-94. [PMID: 25964488 DOI: 10.4049/jimmunol.1500016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/30/2015] [Indexed: 12/31/2022]
Abstract
GTPase of the immunity-associated protein (GIMAP) family members are differentially regulated during human Th cell differentiation and have been previously connected to immune-mediated disorders in animal studies. GIMAP4 is believed to contribute to the Th cell subtype-driven immunological balance via its role in T cell survival. GIMAP5 has a key role in BB-DR rat and NOD mouse lymphopenia. To elucidate GIMAP4 and GIMAP5 function and role in human immunity, we conducted a study combining genetic association in different immunological diseases and complementing functional analyses. Single nucleotide polymorphisms tagging the GIMAP haplotype variation were genotyped in Finnish type 1 diabetes (T1D) families and in a prospective Swedish asthma and allergic sensitization birth cohort. Initially, GIMAP5 rs6965571 was associated with risk for asthma and allergic sensitization (odds ratio [OR] 3.74, p = 0.00072, and OR 2.70, p = 0.0063, respectively) and protection from T1D (OR 0.64, p = 0.0058); GIMAP4 rs13222905 was associated with asthma (OR 1.28, p = 0.035) and allergic sensitization (OR 1.27, p = 0.0068). However, after false discovery rate correction for multiple testing, only the associations of GIMAP4 with allergic sensitization and GIMAP5 with asthma remained significant. In addition, transcription factor binding sites surrounding the associated loci were predicted. A gene-gene interaction in the T1D data were observed between the IL2RA rs2104286 and GIMAP4 rs9640279 (OR 1.52, p = 0.0064) and indicated between INS rs689 and GIMAP5 rs2286899. The follow-up functional analyses revealed lower IL-2RA expression upon GIMAP4 knockdown and an effect of GIMAP5 rs2286899 genotype on protein expression. Thus, the potential role of GIMAP4 and GIMAP5 as modifiers of immune-mediated diseases cannot be discarded.
Collapse
Affiliation(s)
- Mirkka T Heinonen
- Turku Centre of Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland; Department of Biology, University of Turku, 20014 Turku, Finland; Turku Doctoral Programme of Molecular Medicine, University of Turku, 20520 Turku Finland
| | - Antti-Pekka Laine
- Immunogenetics Laboratory, University of Turku, 20520 Turku, Finland
| | - Cilla Söderhäll
- Department of Bioscience and Nutrition and Center for Innovative Medicine, Karolinska Institutet, 141 83 Huddinge, Stockholm, Sweden
| | - Olena Gruzieva
- Institute of Environmental Medicine, Karolinska Institutet, 171 65 Solna, Stockholm, Sweden
| | - Sini Rautio
- Department of Information and Computer Science, Aalto University, 02150 Espoo, Finland
| | - Erik Melén
- Institute of Environmental Medicine, Karolinska Institutet, 171 65 Solna, Stockholm, Sweden; Karolinska University Hospital, Astrid Lindgren Children's Hospital, 171 76 Solna, Stockholm, Sweden
| | - Göran Pershagen
- Institute of Environmental Medicine, Karolinska Institutet, 171 65 Solna, Stockholm, Sweden
| | - Harri J Lähdesmäki
- Turku Centre of Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland; Institute of Environmental Medicine, Karolinska Institutet, 171 65 Solna, Stockholm, Sweden
| | - Mikael Knip
- Children's Hospital, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; Research Programs Unit, Diabetes and Obesity, University of Helsinki, 00290 Helsinki, Finland; Department of Pediatrics, Tampere University Hospital, 33521 Tampere, Finland; Folkhälsan Research Institute, 00290 Helsinki, Finland
| | - Jorma Ilonen
- Immunogenetics Laboratory, University of Turku, 20520 Turku, Finland; Department of Clinical Microbiology, University of Eastern Finland, 70211 Kuopio, Finland; and
| | | | - Juha Kere
- Department of Bioscience and Nutrition and Center for Innovative Medicine, Karolinska Institutet, 141 83 Huddinge, Stockholm, Sweden; Molecular Neurology Research Program, University of Helsinki and Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Riitta Lahesmaa
- Turku Centre of Biotechnology, University of Turku and Åbo Akademi University, 20520 Turku, Finland;
| | | |
Collapse
|
3
|
Abstract
The mechanisms leading to the onset and perpetuation of systemic and tissue-specific autoimmune diseases are complex, and numerous hypotheses have been proposed or confirmed over the past 12 months. It is particularly of note that the number of articles published during 2011 in the major immunology and autoimmunity journals increased by 3 % compared to the previous year. The present article is dedicated to a brief review of the reported data and, albeit not comprehensive of all articles, is aimed at identifying common and future themes. First, clinical researchers were particularly dedicated to defining refractory forms of diseases and to discuss the use and switch of therapeutic monoclonal antibodies in everyday practice. Second, following the plethora of genome-wide association studies reported in most multifactorial diseases, it became clear that genomics cannot fully explain the individual susceptibility and additional environmental or epigenetic factors are necessary. Both these components were widely investigated, both in organ-specific (i.e., type 1 diabetes) and systemic (i.e., systemic lupus erythematosus) diseases. Third, a large number of 2011 works published in the autoimmunity area are dedicated to dissect pathogenetic mechanisms of tolerance breakdown in general or in specific conditions. While our understanding of T regulatory and Th17 cells has significantly increased in 2011, it is of note that most of the proposed lines of evidence identify potential targets for future treatments and should not be overlooked.
Collapse
|