1
|
Stefanski HE, Xing Y, Nicholls J, Jonart L, Goren E, Taylor PA, Mills AA, Riddle M, McGrath J, Tolar J, Hollander GA, Blazar BR. P63 targeted deletion under the FOXN1 promoter disrupts pre-and post-natal thymus development, function and maintenance as well as induces severe hair loss. PLoS One 2022; 17:e0261770. [PMID: 35077450 PMCID: PMC8789144 DOI: 10.1371/journal.pone.0261770] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 12/09/2021] [Indexed: 11/18/2022] Open
Abstract
Progressive immune deficiency of aging is characterized by severe thymic atrophy, contracted T cell repertoire, and poor immune function. p63 is critical for the proliferative potential of embryonic and adult stem cells, as well as thymic epithelial cells (TECs). Because p63 null mice experience rapid post-natal lethality due to epidermal and limb morphogenesis defects, studies to define a role for p63 expression in TEC biology focused on embryonic thymus development and in vitro experiments. Since post-natal thymic stromal development and function differs from that of the embryo, we assessed the impact of lineage-restricted p63 loss on pre- and post-natal murine TEC function by generating mice with a loss of p63 function targeted to TEC, termed p63TECko mice. In adult p63TECko mice, severe thymic hypoplasia was observed with a lack in a discernable segregation into medullary and cortical compartments and peripheral T cell lymphopenia. This profound thymic defect was seen in both neonatal as well as embryonic p63TECko mice. In addition to TECs, p63 also plays in important role in the development of stratified epithelium of the skin; lack of p63 results in defects in skin epidermal stratification and differentiation. Interestingly, all adult p63TECko mice lacked hair follicles despite having normal p63 expression in the skin. Together our results show a critical role of TEC p63 in thymic development and maintenance and show that p63 expression is critical for hair follicle formation.
Collapse
Affiliation(s)
- Heather E. Stefanski
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Yan Xing
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Jemma Nicholls
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Leslie Jonart
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Emily Goren
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Patricia A. Taylor
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Alea A. Mills
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, New York, United States of America
| | - Megan Riddle
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - John McGrath
- Molecular Dermatology, St John’s Institute of Dermatology, King’s College, London, England
| | - Jakub Tolar
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Georg A. Hollander
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- Department of Biomedicine, Basel University Children’s Hospital, University of Basel, Basel, Switzerland
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Bruce R. Blazar
- Division of Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| |
Collapse
|
2
|
Abdulhaqq S, Ventura AB, Reed JS, Bashirova AA, Bateman KB, McDonald E, Wu HL, Greene JM, Schell JB, Morrow D, Wisskirchen K, Martin JN, Deeks SG, Carrington M, Protzer U, Früh K, Hansen SG, Picker LJ, Sacha JB, Bimber BN. Identification and Characterization of Antigen-Specific CD8 + T Cells Using Surface-Trapped TNF-α and Single-Cell Sequencing. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 207:2913-2921. [PMID: 34810222 PMCID: PMC9124229 DOI: 10.4049/jimmunol.2100535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 10/15/2021] [Indexed: 12/31/2022]
Abstract
CD8+ T cells are key mediators of antiviral and antitumor immunity. The isolation and study of Ag-specific CD8+ T cells, as well as mapping of their MHC restriction, has practical importance to the study of disease and the development of therapeutics. Unfortunately, most experimental approaches are cumbersome, owing to the highly variable and donor-specific nature of MHC-bound peptide/TCR interactions. Here we present a novel system for rapid identification and characterization of Ag-specific CD8+ T cells, particularly well suited for samples with limited primary cells. Cells are stimulated ex vivo with Ag of interest, followed by live cell sorting based on surface-trapped TNF-α. We take advantage of major advances in single-cell sequencing to generate full-length sequence data from the paired TCR α- and β-chains from these Ag-specific cells. The paired TCR chains are cloned into retroviral vectors and used to transduce donor CD8+ T cells. These TCR transductants provide a virtually unlimited experimental reagent, which can be used for further characterization, such as minimal epitope mapping or identification of MHC restriction, without depleting primary cells. We validated this system using CMV-specific CD8+ T cells from rhesus macaques, characterizing an immunodominant Mamu-A1*002:01-restricted epitope. We further demonstrated the utility of this system by mapping a novel HLA-A*68:02-restricted HIV Gag epitope from an HIV-infected donor. Collectively, these data validate a new strategy to rapidly identify novel Ags and characterize Ag-specific CD8+ T cells, with applications ranging from the study of infectious disease to immunotherapeutics and precision medicine.
Collapse
Affiliation(s)
- Shaheed Abdulhaqq
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Abigail B Ventura
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Jason S Reed
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Arman A Bashirova
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Katherine B Bateman
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Eric McDonald
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Helen L Wu
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Justin M Greene
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - John B Schell
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - David Morrow
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Karin Wisskirchen
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum Munich, Munich, Germany
| | - Jeffrey N Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA
| | - Steven G Deeks
- HIV/AIDS Program, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Mary Carrington
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD
- Laboratory of Integrative Cancer Immunology, Center for Cancer Research, National Cancer Institute, Bethesda, MD
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA; and
| | - Ulrike Protzer
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum Munich, Munich, Germany
| | - Klaus Früh
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Scott G Hansen
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Louis J Picker
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR
| | - Jonah B Sacha
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR;
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR
| | - Benjamin N Bimber
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR
| |
Collapse
|
3
|
Salami F, Tavassoli A, Mehrzad J, Parham A. Immunomodulatory effects of mesenchymal stem cells on leukocytes with emphasis on neutrophils. Immunobiology 2018; 223:786-791. [DOI: 10.1016/j.imbio.2018.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 08/03/2018] [Indexed: 02/07/2023]
|
4
|
Banerjee S, Chapman SJ. Influence of correlated antigen presentation on T-cell negative selection in the thymus. J R Soc Interface 2018; 15:rsif.2018.0311. [PMID: 30404905 PMCID: PMC6283997 DOI: 10.1098/rsif.2018.0311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 10/08/2018] [Indexed: 11/12/2022] Open
Abstract
The thymus is the primary organ for the generation of naive T cells, a key component of the immune system. Tolerance of T cells to self is achieved primarily in the thymic medulla, where immature T cells (thymocytes) sample self-peptides presented by medullary thymic epithelial cells (mTECs). A sufficiently strong interaction activates the thymocytes leading to negative selection. A key question of current interest is whether there is any structure in the manner in which mTECs present peptides: can any mTEC present any peptide at any time, or are there particular patterns of correlated peptide presentation? We investigate this question using a mathematical model of negative selection. We find that correlated patterns of peptide presentation may be advantageous in negatively selecting low-degeneracy thymocytes (that is, those thymocytes which respond to relatively few peptides). We also quantify the probability that an auto-reactive thymocyte exits the thymus before it encounters a cognate antigen. The results suggest that heterogeneity of gene co-expression in mTECs has an effect on the probability of escape of autoreactive thymocytes.
Collapse
|
5
|
T Lymphocytes and Autoimmunity. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 341:125-168. [DOI: 10.1016/bs.ircmb.2018.05.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
6
|
Stojić-Vukanić Z, Pilipović I, Djikić J, Vujnović I, Nacka-Aleksić M, Bufan B, Arsenović-Ranin N, Kosec D, Leposavić G. Strain specificities in age-related changes in mechanisms promoting and controlling rat spinal cord damage in experimental autoimmune encephalomyelitis. Exp Gerontol 2017; 101:37-53. [PMID: 29128575 DOI: 10.1016/j.exger.2017.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/02/2017] [Accepted: 11/06/2017] [Indexed: 11/20/2022]
Abstract
The study investigated strain specificities in age-related differences in CD8+ T cell- and microglial cell-mediated mechanisms implicated in induction/perpetuation and/or control of neuroinflammation in experimental autoimmune encephalomyelitis (EAE) in Albino Oxford (AO) and Dark Agouti (DA) rats exhibiting age-related changes in the susceptibility to EAE in the opposite direction (increase in relatively resistant AO rats vs decrease in DA rats). In the inductive phase of EAE, the greater number of fully differentiated effector CD8+ T lymphocytes was found in draining lymph nodes (dLNs) from aged rats of both strains than in strain-matched young rats, but this was particularly prominent in AO rats, which exhibited milder EAE of prolonged duration compared with their DA counterparts. Consistently, dLN IFN-γ+ and IL-17+ CD8+ T cell counts were greater in aged AO than in DA rats. Additionally, the magnitudes of myelin basic protein (MBP)-induced rise in the frequency of IFN-γ+ and IL-17+ CD8+ T cells (providing important help to neuroantigen-specific CD4+ T cells in EAE models characterized by clinically mild disease) were greater in dLN cell cultures from aged AO rats. Consistently, the magnitudes of MBP-induced rise in the frequency of both IFN-γ+ and IL-17+ CD8+ T cells were greater in spinal cord mononuclear cell cultures from aged AO rats compared with their DA counterparts. Besides, with aging CD4+CD25+Foxp3+/CD8+CD25+Foxp3+ regulatory T cell ratio changed in spinal cord in the opposite direction. Consequently, in aged AO rats it was shifted towards CD8+CD25+Foxp3+ regulatory T cells (exhibiting lower suppressive capacity) when compared with DA rats. Moreover, the frequency of CX3CR1+ cells among microglia changed with aging and the disease development. In aged rats, in the effector phase of EAE it was lower in AO than in DA rats. This was accompanied by higher frequency of cells expressing IL-1β (whose down-regulation is central for CX3CR1-mediated neuroprotection), but lower that of phagocyting cells among microglia from aged AO compared their DA counterparts. The study indicates the control points linked with strain differences in age-related changes in EAE pathogenesis.
Collapse
Affiliation(s)
- Zorica Stojić-Vukanić
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Ivan Pilipović
- Immunology Research Centre "Branislav Janković", Institute of Virology, Vaccines and Sera "Torlak", 458 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Jasmina Djikić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Ivana Vujnović
- Immunology Research Centre "Branislav Janković", Institute of Virology, Vaccines and Sera "Torlak", 458 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Mirjana Nacka-Aleksić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Biljana Bufan
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Nevena Arsenović-Ranin
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Duško Kosec
- Immunology Research Centre "Branislav Janković", Institute of Virology, Vaccines and Sera "Torlak", 458 Vojvode Stepe, 11221 Belgrade, Serbia
| | - Gordana Leposavić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe, 11221 Belgrade, Serbia.
| |
Collapse
|
7
|
Breser ML, Motrich RD, Sanchez LR, Rivero VE. Chronic Pelvic Pain Development and Prostate Inflammation in Strains of Mice With Different Susceptibility to Experimental Autoimmune Prostatitis. Prostate 2017; 77:94-104. [PMID: 27699823 DOI: 10.1002/pros.23252] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 08/28/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Experimental autoimmune prostatitis (EAP) is an autoimmune inflammatory disease of the prostate characterized by peripheral prostate-specific autoimmune responses associated with prostate inflammation. EAP is induced in rodents upon immunization with prostate antigens (PAg) plus adjuvants and shares important clinical and immunological features with the human disease chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). METHODS EAP was induced in young NOD, C57BL/6, and BALB/c male mice by immunization with PAg plus complete Freund́s adjuvant. Tactile allodynia was assessed using Von Frey fibers as a measure of pelvic pain at baseline and at different time points after immunization. Using conventional histology, immunohistochemistry, FACS analysis, and protein arrays, an interstrain comparative study of prostate cell infiltration and inflammation was performed. RESULTS Chronic pelvic pain development was similar between immunized NOD and C57BL/6 mice, although the severity of leukocyte infiltration was greater in the first case. Coversely, minimal prostate cell infiltration was observed in immunized BALB/c mice, who showed no pelvic pain development. Increased numbers of mast cells, mostly degranulated, were detected in prostate samples from NOD and C57BL/6 mice, while lower total counts and resting were observed in BALB/c mice. Prostate tissue from NOD mice revealed markedly increased expression levels of inflammatory cytokines, chemokines, adhesion molecules, vascular endothelial growth factor, and metalloproteinases. Similar results, but to a lesser extent, were observed when analyzing prostate tissue from C57BL/6 mice. On the contrary, the expression of the above mediators was very low in prostate tissue from immunized BALB/c mice, showing significantly slight increments only for CXCL1 and IL4. CONCLUSIONS Our results provide new evidence indicating that NOD, C57BL/6, and BALB/c mice develop different degrees of chronic pelvic pain, type, and amount of prostate cell infiltration and secretion of inflammatory mediators. Our results corroborate and support the notion that mice with different genetic background have different susceptibility to EAP induction. Prostate 77:94-104, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Maria L Breser
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina
| | - Ruben D Motrich
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina
| | - Leonardo R Sanchez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina
| | - Virginia E Rivero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina
| |
Collapse
|
8
|
Breser ML, Lino AC, Motrich RD, Godoy GJ, Demengeot J, Rivero VE. Regulatory T cells control strain specific resistance to Experimental Autoimmune Prostatitis. Sci Rep 2016; 6:33097. [PMID: 27624792 PMCID: PMC5022010 DOI: 10.1038/srep33097] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 08/19/2016] [Indexed: 12/18/2022] Open
Abstract
Susceptibility to autoimmune diseases results from the encounter of a complex and long evolved genetic context with a no less complex and changing environment. Major actors in maintaining health are regulatory T cells (Treg) that primarily dampen a large subset of autoreactive lymphocytes escaping thymic negative selection. Here, we directly asked whether Treg participate in defining susceptibility and resistance to Experimental Autoimmune Prostatitis (EAP). We analyzed three common laboratory strains of mice presenting with different susceptibility to autoimmune prostatitis upon immunization with prostate proteins. The NOD, the C57BL/6 and the BALB/c mice that can be classified along a disease score ranging from severe, mild and to undetectable, respectively. Upon mild and transient depletion of Treg at the induction phase of EAP, each model showed an increment along this score, most remarkably with the BALB/c mice switching from a resistant to a susceptible phenotype. We further show that disease associates with the upregulation of CXCR3 expression on effector T cells, a process requiring IFNγ. Together with recent advances on environmental factors affecting Treg, these findings provide a likely cellular and molecular explanation to the recent rise in autoimmune diseases incidence.
Collapse
Affiliation(s)
- Maria L Breser
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5016, Córdoba, Argentina
| | | | - Ruben D Motrich
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5016, Córdoba, Argentina
| | - Gloria J Godoy
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5016, Córdoba, Argentina
| | | | - Virginia E Rivero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5016, Córdoba, Argentina
| |
Collapse
|
9
|
Byrd SK. Apoptosis as the focus of an authentic research experience in a cell physiology laboratory. ADVANCES IN PHYSIOLOGY EDUCATION 2016; 40:257-264. [PMID: 27231261 DOI: 10.1152/advan.00176.2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
Curriculum-embedded independent research is a high-impact teaching practice that has been shown to increase student engagement and learning. This article describes a multiweek laboratory project for an upper-division undergraduate cell physiology laboratory using apoptosis via the mitochondrial pathway as the overarching theme. Students did literature research on apoptotic agents that acted via the mitochondrial pathway. Compounds ranged from natural products such as curcumin to synthetic compounds such as etoposide. Groups of two to three students planned a series of experiments using one of three cultured cell lines that required them to 1) learn to culture cells; 2) determine treatment conditions, including apoptotic agent solubility and concentration ranges that had been reported in the literature; 3) choose two methods to validate/quantify apoptotic capacity of the reagent; and 4) attempt to "rescue" cells from undergoing apoptosis using one of several available compounds/methods. In essence, given some reagent and equipment constraints, students designed an independent experiment to highlight the effects of different apoptotic agents on cells in culture. Students presented their experimental designs as in a laboratory group meeting and their final findings as a classroom "symposium." This exercise can be adapted to many different types of laboratories with greater or lesser equipment and instrumentation constraints, incorporates several core cell physiology methods, and encourages key experimental design and critical thinking components of independent research.
Collapse
Affiliation(s)
- Shere K Byrd
- Department of Biology, Fort Lewis College, Durango, Colorado
| |
Collapse
|
10
|
Xiao D, Ye X, Zhang N, Ou M, Guo C, Zhang B, Liu Y, Wang M, Yang G, Jing C. A meta-analysis of interaction between Epstein-Barr virus and HLA-DRB1*1501 on risk of multiple sclerosis. Sci Rep 2015; 5:18083. [PMID: 26656273 PMCID: PMC4676020 DOI: 10.1038/srep18083] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/11/2015] [Indexed: 11/09/2022] Open
Abstract
Infection with Epstein-Barr virus (EBV) and HLA-DRB1*1501-positivity is a risk factor for multiple sclerosis (MS), but whether an interaction between these two factors causes MS is unclear. We therefore conducted a meta-analysis on the effect of the interaction between HLA-DRB1*1501 and EBV infection on MS. Searches of PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and the Wanfan databases through February 2015 yielded 5 studies that met the criteria for inclusion in the meta-analysis. EBV infection and HLA-DRB1*1501-positivity were dichotomized. The additive (S) and multiplicative interaction indexes (OR) between EBV infection and HLA-DRB1*1501 and their 95% confidence intervals (95%CI) were calculated for each study and then combined in a meta-analysis. EBV infection was significantly associated with MS (OR = 2.60; 95%CI, 1.48–4.59). HLA-DRB1*1501 was associated with a significantly increased risk of MS (OR, 3.06; 95%CI, 2.30–4.08). An interaction effect between EBV infection and HLA-DRB1*1501 on MS was observed on the additive scale (S, 1.43; 95%CI, 1.05–1.95, P = 0.023), but no interaction effect was observed on the multiplicative scale (OR, 0.86, 95%CI, 0.59–1.26). This meta-analysis provides strong evidence that EBV alone, HLA-DRB1*1501 alone or their interaction is associated with an elevated risks of MS.
Collapse
Affiliation(s)
- Di Xiao
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Xingguang Ye
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Na Zhang
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Meiling Ou
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Congcong Guo
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Baohuan Zhang
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Yang Liu
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Man Wang
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Guang Yang
- Department of Parasitology, School of Medicine, Jinan University, No.601, Huangpu Avenue West, Guangzhou, Guangdong, China.,Key Laboratory of environmental exposure and health in Guangzhou, Jinan University, Guangzhou, Guangdong, China
| | - Chunxia Jing
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China.,Key Laboratory of environmental exposure and health in Guangzhou, Jinan University, Guangzhou, Guangdong, China
| |
Collapse
|
11
|
Siggs OM, Miosge LA, Daley SR, Asquith K, Foster PS, Liston A, Goodnow CC. Quantitative reduction of the TCR adapter protein SLP-76 unbalances immunity and immune regulation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:2587-95. [PMID: 25662996 PMCID: PMC4355390 DOI: 10.4049/jimmunol.1400326] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gene variants that disrupt TCR signaling can cause severe immune deficiency, yet less disruptive variants are sometimes associated with immune pathology. Null mutations of the gene encoding the scaffold protein Src homology 2 domain-containing leukocyte protein of 76 kDa (SLP-76), for example, cause an arrest of T cell positive selection, whereas a synthetic membrane-targeted allele allows limited positive selection but is associated with proinflammatory cytokine production and autoantibodies. Whether these and other enigmatic outcomes are due to a biochemical uncoupling of tolerogenic signaling, or simply a quantitative reduction of protein activity, remains to be determined. In this study we describe a splice variant of Lcp2 that reduced the amount of wild-type SLP-76 protein by ~90%, disrupting immunogenic and tolerogenic pathways to different degrees. Mutant mice produced excessive amounts of proinflammatory cytokines, autoantibodies, and IgE, revealing that simple quantitative reductions of SLP-76 were sufficient to trigger immune dysregulation. This allele reveals a dose-sensitive threshold for SLP-76 in the balance of immunity and immune dysregulation, a common disturbance of atypical clinical immune deficiencies.
Collapse
Affiliation(s)
- Owen M Siggs
- Department of Immunology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia; Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom;
| | - Lisa A Miosge
- Department of Immunology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Stephen R Daley
- Department of Immunology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Kelly Asquith
- Priority Research Centre for Asthma and Respiratory Diseases, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales 2300, Australia; and
| | - Paul S Foster
- Priority Research Centre for Asthma and Respiratory Diseases, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales 2300, Australia; and
| | - Adrian Liston
- Department of Microbiology and Immunology, Flanders Institute for Biotechnology and University of Leuven, Leuven 3000, Belgium
| | - Christopher C Goodnow
- Department of Immunology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia;
| |
Collapse
|
12
|
Bach MP, Hug E, Werner M, Holch J, Sprissler C, Pechloff K, Zirlik K, Zeiser R, Dierks C, Ruland J, Jumaa H. Premature terminal differentiation protects from deregulated lymphocyte activation by ITK-Syk. THE JOURNAL OF IMMUNOLOGY 2013; 192:1024-33. [PMID: 24376268 DOI: 10.4049/jimmunol.1300420] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The development of hematopoietic neoplasms is often associated with mutations, altered gene expression or chromosomal translocations. Recently, the t(5, 9)(q33;q22) translocation was found in a subset of peripheral T cell lymphomas and was shown to result in an IL-2-inducible kinase-spleen tyrosine kinase (ITK-Syk) fusion transcript. In this study, we show that T cell-specific expression of the ITK-Syk oncogene in mice leads to an early onset and aggressive polyclonal T cell lymphoproliferation with concomitant B cell expansion and systemic inflammation by 7-9 wk of age. Because this phenotype is strikingly different from previous work showing that ITK-Syk expression causes clonal T cell lymphoma by 20-27 wk of age, we investigated the underlying molecular mechanism in more detail. We show that the reason for the severe phenotype is the lack of B-lymphocyte-induced maturation protein-1 (Blimp-1) induction by low ITK-Syk expression. In contrast, high ITK-Syk oncogene expression induces terminal T cell differentiation in the thymus by activating Blimp-1, thereby leading to elimination of oncogene-expressing cells early in development. Our data suggest that terminal differentiation is an important mechanism to prevent oncogene-expressing cells from malignant transformation, as high ITK-Syk oncogene activity induces cell elimination. Accordingly, for transformation, a specific amount of oncogene is required, or alternatively, the induction of terminal differentiation is defective.
Collapse
Affiliation(s)
- Martina P Bach
- Institute of Immunology, University Clinics Ulm, 89081 Ulm, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Role of caspase-8 in thymus function. Cell Death Differ 2013; 21:226-33. [PMID: 24270406 DOI: 10.1038/cdd.2013.166] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 08/20/2013] [Accepted: 09/12/2013] [Indexed: 01/07/2023] Open
Abstract
The thymus is the primary organ responsible for de novo generation of immunocompetent T cells that have a diverse repertoire of antigen recognition. During the developmental process, 98% of thymocytes die by apoptosis. Thus apoptosis is a dominant process in the thymus and occurs through either death by neglect or negative selection or through induction by stress/aging. Caspase activation is an essential part of the general apoptosis mechanism, and data suggest that caspases may have a role in negative selection; however, it seems more probable that caspase-8 activation is involved in death by neglect, particularly in glucocorticoid-induced thymocyte apoptosis. Caspase-8 is active in double-positive (DP) thymocytes in vivo and can be activated in vitro in DP thymocytes by T-cell receptor (TCR) crosslinking to induce apoptosis. Caspase-8 is a proapoptotic member of the caspase family and is considered an initiator caspase, which is activated upon stimulation of a death receptor (e.g., Fas), recruitment of the adaptor molecule FADD, and recruitment and subsequent processing of procaspase-8. The main role of caspase-8 seems to be pro-apoptotic and, in this review, we will discuss about the involvement of caspase-8 in (1) TCR-triggered thymic apoptosis; (2) death receptor-mediated thymic apoptosis; and (3) glucocorticoid-induced thymic apoptosis. Regarding TCR triggering, caspase-8 is active in medullary, semi-mature heat-stable antigen(hi) (HAS(hi) SP) thymocytes as a consequence of strong TCR stimulation. The death receptors Fas, FADD, and FLIP are involved upstream of caspase-8 activation in apoptosis; whereas, Bid and HDAC7 are involved downstream of caspase-8. Finally, caspase-8 is involved in glucocortocoid-induced thymocyte apoptosis through an activation loop with the protein GILZ. GILZ activates caspase-8, promoting GILZ sumoylation and its protection from proteasomal degradation.
Collapse
|
14
|
Talabér G, Jondal M, Okret S. Extra-adrenal glucocorticoid synthesis: immune regulation and aspects on local organ homeostasis. Mol Cell Endocrinol 2013; 380:89-98. [PMID: 23707789 DOI: 10.1016/j.mce.2013.05.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 04/22/2013] [Accepted: 05/07/2013] [Indexed: 12/21/2022]
Abstract
Systemic glucocorticoids (GCs) mainly originate from de novo synthesis in the adrenal cortex under the control of the hypothalamus-pituitary-adrenal (HPA)-axis. However, research during the last 1-2 decades has revealed that additional organs express the necessary enzymes and have the capacity for de novo synthesis of biologically active GCs. This includes the thymus, intestine, skin and the brain. Recent research has also revealed that locally synthesized GCs most likely act in a paracrine or autocrine manner and have significant physiological roles in local homeostasis, cell development and immune cell activation. In this review, we summarize the nature, regulation and known physiological roles of extra-adrenal GC synthesis. We specifically focus on the thymus in which GC production (by both developing thymocytes and epithelial cells) has a role in the maintenance of proper immunological function.
Collapse
Affiliation(s)
- Gergely Talabér
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, SE-141 83 Huddinge, Sweden
| | | | | |
Collapse
|
15
|
Pioli PD, Dahlem TJ, Weis JJ, Weis JH. Deletion of Snai2 and Snai3 results in impaired physical development compounded by lymphocyte deficiency. PLoS One 2013; 8:e69216. [PMID: 23874916 PMCID: PMC3713067 DOI: 10.1371/journal.pone.0069216] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 06/05/2013] [Indexed: 11/26/2022] Open
Abstract
The Snail family of transcriptional regulators consists of three highly conserved members. These proteins regulate (repress) transcription via the recruitment of histone deacetylases to target gene promoters that possess the appropriate E-box binding sequences. Murine Snai1 is required for mouse development while Snai2 deficient animals survive with some anomalies. Less is known about the third member of the family, Snai3. To investigate the function of Snai3, we generated a conditional knockin mouse. Utilizing Cre-mediated deletion to facilitate the ablation of Snai3 in T cells or the entire animal, we found little to no effect of the loss of Snai3 in the entire animal or in T cell lineages. This finding provided the hypothesis that absence of Snai3 was mitigated, in part, by the presence of Snai2. To test this hypothesis we created Snai2/Snai3 double deficient mice. The developmental consequences of lacking both of these proteins was manifested in stunted growth, a paucity of offspring including a dramatic deficiency of female mice, and impaired immune cell development within the lymphoid lineages.
Collapse
Affiliation(s)
- Peter D. Pioli
- The Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Timothy J. Dahlem
- The Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Janis J. Weis
- The Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - John H. Weis
- The Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| |
Collapse
|
16
|
Mingueneau M, Jiang W, Feuerer M, Mathis D, Benoist C. Thymic negative selection is functional in NOD mice. ACTA ACUST UNITED AC 2012; 209:623-37. [PMID: 22329992 PMCID: PMC3302233 DOI: 10.1084/jem.20112593] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Based on analyses of multiple TCR transgenic (tg) models, the emergence of pathogenic T cells in diabetes-prone NOD mice has been ascribed to a failure to censure autoreactive clones in the thymus. In contrast, using isolated and preselected thymocytes, we show that nonobese diabetic (NOD) genetic variation impairs neither clonal deletion nor downstream transcriptional programs. However, we find that NOD genetic variation influences αβ/γδ-lineage decisions promoted by early expression of tg αβ-TCRs at the double-negative (DN) stage. In B6 and other genetic backgrounds, tg αβ-TCRs behave like γδ-TCRs and commit a large fraction of DNs toward the γδ-lineage, thereby decreasing the size of the double-positive (DP) pool, which is efficiently positively and negatively selected. In NOD DNs, αβ-TCR signalosomes instead behave like pre-TCRs, resulting in high numbers of DPs competing for limited selection niches, and poor positive and negative selection. Once niche effects are neutralized in mixed bone marrow chimeras, positive and negative selection are equally efficient on B6 and NOD backgrounds. Biochemical analysis revealed a selective defect in the activation of Erk1/2 downstream of NOD αβ-TCR signalosomes. Therefore, NOD genetic variation influences αβ/γδ-lineage decisions when the αβ-TCR heterodimer is prematurely expressed, but not the process of negative selection.
Collapse
Affiliation(s)
- Michael Mingueneau
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | |
Collapse
|
17
|
ORAI-mediated calcium influx in T cell proliferation, apoptosis and tolerance. Cell Calcium 2011; 50:261-9. [DOI: 10.1016/j.ceca.2011.05.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/12/2011] [Accepted: 05/13/2011] [Indexed: 12/25/2022]
|
18
|
Wolfson MY, Nam K, Chakraborty AK. The effect of mutations on the alloreactive T cell receptor/peptide-MHC interface structure: a molecular dynamics study. J Phys Chem B 2011; 115:8317-27. [PMID: 21651302 PMCID: PMC3131071 DOI: 10.1021/jp202471d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
T cells orchestrate adaptive, pathogen-specific immune responses. T cells have a surface receptor (called TCR) whose ligands are complexes (pMHCs) of peptides (derived from pathogens or host proteins) and major histocompatibility complex proteins (MHCs). MHC proteins vary between hosts. During organ transplants, host TCRs interact with peptides present in complex with genetically different MHCs. This usually causes a vigorous immune response: alloreactivity. Studies of alloreactive protein interactions have yielded results that present a puzzle. Some crystallographic studies concluded that the alloreactive TCR/MHC interface is essentially unaffected by changing the TCR peptide-binding region, suggesting that the peptide does not influence the interface. Another biochemical study concluded from mutation data that different peptides can alter the binding interface with the same TCR. To explore the origin of this puzzle, we used molecular dynamics simulations to study the dependence of the TCR/pMHC interface on changes in both the peptide and the TCR. Our simulations show that the footprint of the TCR on the pMHC is insensitive to mutations of the TCR peptide-binding loops, but peptide mutations can make multiple local changes to TCR/pMHC contacts. Therefore, our results demonstrate that the structural and mutation data do not conflict and reveal how subtle, but important, characteristics of the alloreactive TCR/pMHC interface are influenced by the TCR and the peptide.
Collapse
Affiliation(s)
| | - Kwangho Nam
- To whom correspondence should be addressed: ; , Phone: +1 617 495 8997; +1 617 253 3890. Fax: +1 617 495 8755; +1 617 253 2272
| | - Arup K. Chakraborty
- To whom correspondence should be addressed: ; , Phone: +1 617 495 8997; +1 617 253 3890. Fax: +1 617 495 8755; +1 617 253 2272
| |
Collapse
|
19
|
The transposon-driven evolutionary origin and basis of histone deacetylase functions and limitations in disease prevention. Clin Epigenetics 2011; 2:97-112. [PMID: 22704332 PMCID: PMC3365375 DOI: 10.1007/s13148-011-0020-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 01/03/2011] [Indexed: 12/19/2022] Open
Abstract
Histone deacetylases (HDACs) are homologous to prokaryotic enzymes that removed acetyl groups from non-histone proteins before the evolution of eukaryotic histones. Enzymes inherited from prokaryotes or from a common ancestor were adapted for histone deacetylation, while useful deacetylation of non-histone proteins was selectively retained. Histone deacetylation served to prevent transcriptions with pathological consequences, including the expression of viral DNA and the deletion or dysregulation of vital genes by random transposon insertions. Viruses are believed to have evolved from transposons, with transposons providing the earliest impetus of HDAC evolution. Because of the wide range of genes potentially affected by transposon insertions, the range of diseases that can be prevented by HDACs is vast and inclusive. Repressive chromatin modifications that may prevent transcription also include methylation of selective lysine residues of histones H3 and H4 and the methylation of selective DNA cytosines following specific histone lysine methylation. Methylation and acetylation of individual histone residues are mutually exclusive. While transposons were sources of disease to be prevented by HDAC evolution, they were also the source of numerous and valuable coding and regulatory sequences recruited by “molecular domestication.” Those sequences contribute to evolved complex transcription regulation in which components with contradictory effects, such as HDACs and HATs, may be coordinated and complementary. Within complex transcription regulation, however, HDACs remain ineffective as defense against some critical infectious and non-infectious diseases because evolutionary compromises have rendered their activity transient.
Collapse
|
20
|
Hoyne GF, Flening E, Yabas M, Teh C, Altin JA, Randall K, Thien CBF, Langdon WY, Goodnow CC. Visualizing the role of Cbl-b in control of islet-reactive CD4 T cells and susceptibility to type 1 diabetes. THE JOURNAL OF IMMUNOLOGY 2011; 186:2024-32. [PMID: 21248249 DOI: 10.4049/jimmunol.1002296] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The E3 ubiquitin ligase Cbl-b regulates T cell activation thresholds and has been associated with protecting against type 1 diabetes, but its in vivo role in the process of self-tolerance has not been examined at the level of potentially autoaggressive CD4(+) T cells. In this study, we visualize the consequences of Cbl-b deficiency on self-tolerance to lysozyme Ag expressed in transgenic mice under control of the insulin promoter (insHEL). By tracing the fate of pancreatic islet-reactive CD4(+) T cells in prediabetic 3A9-TCR × insHEL double-transgenic mice, we find that Cbl-b deficiency contrasts with AIRE or IL-2 deficiency, because it does not affect thymic negative selection of islet-reactive CD4(+) cells or the numbers of islet-specific CD4(+) or CD4(+)Foxp3(+) T cells in the periphery, although it decreased differentiation of inducible regulatory T cells from TGF-β-treated 3A9-TCR cells in vitro. When removed from regulatory T cells and placed in culture, Cblb-deficient islet-reactive CD4(+) cells reveal a capacity to proliferate to HEL Ag that is repressed in wild-type cells. This latent failure of T cell anergy is, nevertheless, controlled in vivo in prediabetic mice so that islet-reactive CD4(+) cells in the spleen and the pancreatic lymph node of Cblb-deficient mice show no evidence of increased activation or proliferation in situ. Cblb deficiency subsequently precipitated diabetes in most TCR:insHEL animals by 15 wk of age. These results reveal a role for peripheral T cell anergy in organ-specific self-tolerance and illuminate the interplay between Cblb-dependent anergy and other mechanisms for preventing organ-specific autoimmunity.
Collapse
Affiliation(s)
- Gerard F Hoyne
- Department of Immunology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Kato Z, Stern JNH, Nakamura HK, Miyashita N, Kuwata K, Kondo N, Strominger JL. The autoimmune TCR-Ob.2F3 can bind to MBP85-99/HLA-DR2 having an unconventional mode as in TCR-Ob.1A12. Mol Immunol 2011; 48:314-20. [PMID: 20810170 DOI: 10.1016/j.molimm.2010.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 06/30/2010] [Accepted: 07/18/2010] [Indexed: 11/18/2022]
Abstract
The generation of T cell receptor (TCR) sequence diversity can produce 'forbidden' clones able to recognize self-antigens. Here, the structure of the complex between a myelin basic protein peptide (MBP85-99), human leukocyte antigen (HLA)-DR2 (DRB1*1501/DRA) and TCR-Ob.2F3, the dominant autoimmune clone obtained from a multiple sclerosis (MS) patient, has been determined using structural docking simulation and dynamics in silico and compared to the structure of TCR-Ob.1A12 complexes with the same MHC/peptide determined by X-ray crystallography. The two TCRs differ by three amino acids in the CDR3 α and β loops. As the result different hydrogen bonds are formed between the two CDR3β loops and the peptide in the complexes of the simulated structures, with three hydrogen bonds seen in the TCR-Ob.2F3 complex and five in the TCR-Ob.1A12 complex. The two TCRs, each located near the N-terminal end of the HLA-DR2 binding groove and both had an orthogonal binding axis but they deviated by about 10°. Simulation methods, such as structural docking and molecular dynamics as used here, provide an avenue to understand molecular binding mode efficiently and more rapidly than obtaining multiple crystal structures when a large structural database is already available.
Collapse
Affiliation(s)
- Zenichiro Kato
- Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02193, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Abstract
Proper regulation of T cell death is of vital importance for the function of the immune system. Positive and negative selection of developing T cells in the thymus ensures the survival of only those T cells that can recognize peptides presented by self-MHC molecules and at the same time not respond to self-antigens, and thus, T cell death within the thymus is instrumental in shaping the mature T cell repertoire. The death of activated peripheral T cells is crucial for processes such as down-modulation of immune responses after clearance of infectious agents, peripheral tolerance, and maintenance of immune-privileged sites. These processes are largely proceeding due to the enhanced susceptibility of activated T cells to spontaneous, activation-, and Fas-induced apoptosis. The active metabolite of the immune regulator vitamin A, retinoic acid, has been reported to influence various types of apoptotic processes in both thymocytes and activated peripheral T cells. This chapter gives an overview of, and discusses the reported effects of vitamin A on spontaneous and activation-induced cell death of thymocytes and mature T cells, as well as on Fas-induced T cell death.
Collapse
|
23
|
Abstract
The development of regulatory T (Treg) cells is essential for the maintenance of immune tolerance and homeostasis. Here, we review recent studies that have advanced our understanding of Treg cell differentiation. In the thymus, TCR specificity to self-antigen appears to be a primary determinant for Treg cell lineage commitment, with c-Rel being an important factor that links T cell receptor (TCR) engagement and Foxp3 expression, along with cytokines and costimulatory molecules. It is also clear that postthymic events shape the peripheral Treg cell population. This includes preferential maintenance of Treg cells specific to self-antigens presented in the periphery, as well as the de novo generation of Treg cells from conventional Foxp3(-) T cells. The process of peripheral Treg cell differentiation shares some features with thymic Treg cell development, but there are notable differences. Together, thymic and peripheral Treg cell differentiation appear to generate an "imprint" of both self- and foreign antigens in the peripheral Treg cell population to provide dominant tolerance.
Collapse
Affiliation(s)
- Hyang-Mi Lee
- Department of Internal Medicine, Division of Rheumatology, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | | |
Collapse
|
24
|
First use of thymus transplantation therapy for FOXN1 deficiency (nude/SCID): a report of 2 cases. Blood 2010; 117:688-96. [PMID: 20978268 DOI: 10.1182/blood-2010-06-292490] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
FOXN1 deficiency is a primary immunodeficiency characterized by athymia, alopecia totalis, and nail dystrophy. Two infants with FOXN1 deficiency were transplanted with cultured postnatal thymus tissue. Subject 1 presented with disseminated Bacillus Calmette-Guérin infection and oligoclonal T cells with no naive markers. Subject 2 had respiratory failure, human herpes virus 6 infection, cytopenias, and no circulating T cells. The subjects were given thymus transplants at 14 and 9 months of life, respectively. Subject 1 received immunosuppression before and for 10 months after transplantation. With follow up of 4.9 and 2.9 years, subjects 1 and 2 are well without infectious complications. The pretransplantation mycobacterial disease in subject 1 and cytopenias in subject 2 resolved. Subject 2 developed autoimmune thyroid disease 1.6 years after transplantation. Both subjects developed functional immunity. Subjects 1 and 2 have 1053/mm(3) and 1232/mm(3) CD3(+) cells, 647/mm(3) and 868/mm(3) CD4(+) T cells, 213/mm(3) and 425/mm(3) naive CD4(+) T cells, and 10 200 and 5700 T-cell receptor rearrangement excision circles per 100 000 CD3(+) cells, respectively. They have normal CD4 T-cell receptor β variable repertoires. Both subjects developed antigen-specific proliferative responses and have discontinued immunoglobulin replacement. In summary, thymus transplantation led to T-cell reconstitution and function in these FOXN1 deficient infants.
Collapse
|
25
|
Takahama Y, Nitta T, Mat Ripen A, Nitta S, Murata S, Tanaka K. Role of thymic cortex-specific self-peptides in positive selection of T cells. Semin Immunol 2010; 22:287-93. [DOI: 10.1016/j.smim.2010.04.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 04/23/2010] [Indexed: 01/22/2023]
|
26
|
Kroger CJ, Flores RR, Morillon M, Wang B, Tisch R. Dysregulation of thymic clonal deletion and the escape of autoreactive T cells. Arch Immunol Ther Exp (Warsz) 2010; 58:449-57. [PMID: 20872284 DOI: 10.1007/s00005-010-0100-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 06/25/2010] [Indexed: 12/25/2022]
Abstract
Events ongoing in the thymus are critical for deleting developing thymocytes specific for tissue antigens, and establishing self-tolerance within the T cell compartment. Aberrant thymic negative selection, however, is believed to generate a repertoire with increased self-reactivity, which in turn can contribute to the development of T cell-mediated autoimmunity. In this review, mechanisms that regulate the efficacy of negative selection and influence the deletion of autoreactive thymocytes will be discussed.
Collapse
Affiliation(s)
- Charles J Kroger
- Department of Microbiology and Immunology, University of North Carolina, Mary Ellen Jones Bldg., Room 635, Campus Box 7290, Chapel Hill, NC 27599-7290, USA
| | | | | | | | | |
Collapse
|
27
|
Filbert EL, Nguyen A, Markiewicz MA, Fowlkes BJ, Huang YH, Shaw AS. Kinase suppressor of Ras 1 is required for full ERK activation in thymocytes but not for thymocyte selection. Eur J Immunol 2010; 40:3226-34. [PMID: 20865788 DOI: 10.1002/eji.201040349] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 08/03/2010] [Accepted: 08/12/2010] [Indexed: 11/06/2022]
Abstract
The scaffold protein kinase suppressor of Ras 1 (KSR1) is critical for efficient activation of ERK in a number of cell types. Consistent with this, we observed a defect in ERK activation in thymocytes that lack KSR1. Interestingly, we found that the defect was much greater after PMA stimulation than by CD3 activation. Since ERK activation is believed to be important for thymocyte development, we analyzed thymocyte selection in KSR1-deficient (KSR1(-/-) ) mice. We found that positive selection in two different TCR transgenic models, HY and AND, was normal. On the other hand, negative selection in the HY model was slightly impaired in KSR1(-/-) mice. However, a defect in negative selection was not apparent in the AND TCR model system or in an endogenous superantigen-mediated model of negative selection. These results suggest that, despite a requirement for KSR1 for full ERK activation in thymocytes, full and efficient ERK activation is not essential for the majority of thymocyte selection events.
Collapse
Affiliation(s)
- Erin L Filbert
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | | | | | | | | | | |
Collapse
|
28
|
Fayard E, Moncayo G, Hemmings BA, Holländer GA. Phosphatidylinositol 3-kinase signaling in thymocytes: the need for stringent control. Sci Signal 2010; 3:re5. [PMID: 20716765 DOI: 10.1126/scisignal.3135re5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The thymus serves as the primary site for the lifelong formation of new T lymphocytes; hence, it is essential for the maintenance of an effective immune system. Although thymocyte development has been widely studied, the mechanisms involved are incompletely defined. A comprehensive understanding of the molecular events that control regular thymocyte development will not only shed light on the physiological control of T cell differentiation but also probably provide insight into the pathophysiology of T cell immunodeficiencies, the molecular basis that underpins autoimmunity, and the mechanisms that instigate the formation of T cell lymphomas. Phosphatidylinositol 3-kinases (PI3Ks) play a critical role in thymocyte development, although not all of their downstream mediators have yet been identified. Here, we discuss experimental evidence that argues for a critical role of the PI3K-phosphoinositide-dependent protein kinase (PDK1)-protein kinase B (PKB) signaling pathway in the development of both normal and malignant thymocytes, and we highlight molecules that can potentially be targeted therapeutically.
Collapse
Affiliation(s)
- Elisabeth Fayard
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
| | | | | | | |
Collapse
|
29
|
Abstract
Higher organisms, such as humans, have an adaptive immune system that usually enables them to successfully combat diverse (and evolving) microbial pathogens. The adaptive immune system is not preprogrammed to respond to prescribed pathogens. Yet it mounts pathogen-specific responses against diverse microbes and establishes memory of past infections (the basis of vaccination). Although major advances have been made in understanding pertinent molecular and cellular phenomena, the mechanistic principles that govern many aspects of an immune response are not known. We illustrate how complementary approaches from the physical and life sciences can help confront this challenge. Specifically, we describe work that brings together statistical mechanics and cell biology to shed light on how key molecular/cellular components of the adaptive immune system are selected to enable pathogen-specific responses. We hope these examples encourage physical chemists to work at this crossroad of disciplines where fundamental discoveries with implications for human health might be made.
Collapse
Affiliation(s)
- Arup K Chakraborty
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
| | | |
Collapse
|
30
|
Schwartz M, Shechter R. Protective autoimmunity functions by intracranial immunosurveillance to support the mind: The missing link between health and disease. Mol Psychiatry 2010; 15:342-54. [PMID: 20332793 DOI: 10.1038/mp.2010.31] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Circulating immune cells support hippocampal neurogenesis, spatial memory, expression of brain-derived neurotrophic factor, and resilience to stress. Nevertheless, considering the immune privileged status of the central nervous system (CNS), such cells were assumed to be excluded from the healthy brain. It is evident, however, that the CNS is continuously surveyed by leukocytes, though their function is still a mystery. Coupling this routine leukocyte trafficking with the function attributed to circulating T cells in brain plasticity led us to propose here that CNS immunosurveillance is an integral part of the functioning brain. Anatomical restriction of selected self-recognizing leukocytes to the brain's borders and fluids (cerebrospinal fluid) not only supports the brain's activity, but also controls the potential aggressiveness of such cells. Accordingly, the brain's 'privilege' is its acquisition of a private peripheral immunological niche under its own control, which supports brain function. Immune malfunction may comprise a missing link between a healthy and diseased mind.
Collapse
Affiliation(s)
- M Schwartz
- The Department of Neurobiology, The Weizmann Institute of Science, Rehovot 76100, Israel.
| | | |
Collapse
|
31
|
Markert ML, Devlin BH, McCarthy EA. Thymus transplantation. Clin Immunol 2010; 135:236-46. [PMID: 20236866 DOI: 10.1016/j.clim.2010.02.007] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/12/2010] [Accepted: 02/12/2010] [Indexed: 11/29/2022]
Abstract
Thymus transplantation is a promising investigational therapy for infants born with no thymus. Because of the athymia, these infants lack T cell development and have a severe primary immunodeficiency. Although thymic hypoplasia or aplasia is characteristic of DiGeorge anomaly, in "complete" DiGeorge anomaly, there is no detectable thymus as determined by the absence of naive (CD45RA(+), CD62L(+)) T cells. Transplantation of postnatal allogeneic cultured thymus tissue was performed in sixty subjects with complete DiGeorge anomaly who were under the age of 2 years. Recipient survival was over 70%. Naive T cells developed 3-5 months after transplantation. The graft recipients were able to discontinue antibiotic prophylaxis, and immunoglobulin replacement. Immunosuppression was used in a subset of subjects but was discontinued when naive T cells developed. The adverse events have been acceptable with thyroid disease being the most common. Research continues on mechanisms underlying immune reconstitution after thymus transplantation.
Collapse
Affiliation(s)
- M Louise Markert
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA.
| | | | | |
Collapse
|
32
|
Thien CBF, Dagger SA, Steer JH, Koentgen F, Jansen ES, Scott CL, Langdon WY. c-Cbl promotes T cell receptor-induced thymocyte apoptosis by activating the phosphatidylinositol 3-kinase/Akt pathway. J Biol Chem 2010; 285:10969-81. [PMID: 20133944 DOI: 10.1074/jbc.m109.094920] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The ability of thymocytes to assess T cell receptor (TCR) signaling strength and initiate the appropriate downstream response is crucial for determining their fate. We have previously shown that a c-Cbl RING finger mutant knock-in mouse, in which the E3 ubiquitin ligase activity of c-Cbl is inactivated, is highly sensitive to TCR-induced death signals that cause thymic deletion. This high intensity signal involves the enhanced tyrosine phosphorylation of the mutant c-Cbl protein promoting a marked increase in the activation of Akt. Here we show that this high intensity signal in c-Cbl RING finger mutant thymocytes also promotes the enhanced induction of two mediators of TCR-directed thymocyte apoptosis, Nur77 and the pro-apoptotic Bcl-2 family member, Bim. In contrast, a knock-in mouse harboring a mutation at Tyr-737, the site in c-Cbl that activates phosphatidylinositol 3-kinase, shows reduced TCR-mediated responses including suppression of Akt activation, a reduced induction of Nur77 and Bim, and greater resistance to thymocyte death. These findings identify tyrosine-phosphorylated c-Cbl as a critical sensor of TCR signal strength that regulates the engagement of death-promoting signals.
Collapse
Affiliation(s)
- Christine B F Thien
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley 6009,Western Australia
| | | | | | | | | | | | | |
Collapse
|
33
|
Nitta T, Murata S, Sasaki K, Fujii H, Ripen AM, Ishimaru N, Koyasu S, Tanaka K, Takahama Y. Thymoproteasome shapes immunocompetent repertoire of CD8+ T cells. Immunity 2009; 32:29-40. [PMID: 20045355 DOI: 10.1016/j.immuni.2009.10.009] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 10/03/2009] [Accepted: 10/14/2009] [Indexed: 12/21/2022]
Abstract
How self-peptides displayed in the thymus contribute to the development of immunocompetent and self-protective T cells is largely unknown. In contrast, the role of thymic self-peptides in eliminating self-reactive T cells and thereby preventing autoimmunity is well established. A type of proteasome, termed thymoproteasome, is specifically expressed by thymic cortical epithelial cells (cTECs) and is required for the generation of optimal cellularity of CD8+ T cells. Here, we show that cTECs displayed thymoproteasome-specific peptide-MHC class I complexes essential for the positive selection of major and diverse repertoire of MHC class I-restricted T cells. CD8+ T cells generated in the absence of thymoproteasomes displayed a markedly altered T cell receptor repertoire that was defective in both allogeneic and antiviral responses. These results demonstrate that thymoproteasome-dependent self-peptide production is required for the development of an immunocompetent repertoire of CD8+ T cells.
Collapse
Affiliation(s)
- Takeshi Nitta
- Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Oh KI, Seo JN. Expression pattern of immunoproteasome subunits in human thymus. Immune Netw 2009; 9:285-8. [PMID: 20157616 PMCID: PMC2816962 DOI: 10.4110/in.2009.9.6.285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 12/07/2009] [Accepted: 12/10/2009] [Indexed: 01/18/2023] Open
Abstract
The expression pattern of immunoproteasomes in human thymus has not been analyzed but may have important consequences during thymic selection. Here we examined the expression patterns of immunoproteasome subunits in fetal and adult thymic tissues by immunohistochemistry and found that all three subunits are expressed in both cortical and medullary stromal cells. These data suggest that thymic selection in human can be affected by peptide repertoires generated by immunoproteasomes.
Collapse
Affiliation(s)
- Kwon Ik Oh
- Department of Pathology, Hallym University College of Medicine, Chuncheon 200-702, Korea
| | | |
Collapse
|
35
|
Stephen TL, Tikhonova A, Riberdy JM, Laufer TM. The activation threshold of CD4+ T cells is defined by TCR/peptide-MHC class II interactions in the thymic medulla. THE JOURNAL OF IMMUNOLOGY 2009; 183:5554-62. [PMID: 19843939 DOI: 10.4049/jimmunol.0901104] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immature thymocytes that are positively selected based upon their response to self-peptide-MHC complexes develop into mature T cells that are not overtly reactive to those same complexes. Developmental tuning is the active process through which TCR-associated signaling pathways of single-positive thymocytes are attenuated to respond appropriately to the peptide-MHC molecules that will be encountered in the periphery. In this study, we explore the mechanisms that regulate the tuning of CD4(+) single-positive T cells to MHC class II encountered in the thymic medulla. Experiments with murine BM chimeras demonstrate that tuning can be mediated by MHC class II expressed by either thymic medullary epithelial cells or thymic dendritic cells. Tuning does not require the engagement of CD4 by MHC class II on stromal cells. Rather, it is mediated by interactions between MHC class II and the TCR. To understand the molecular changes that distinguish immature hyperactive T cells from tuned mature CD4(+) T cells, we compared their responses to TCR stimulation. The altered response of mature CD4 single-positive thymocytes is characterized by the inhibition of ERK activation by low-affinity self-ligands and increased expression of the inhibitory tyrosine phosphatase SHP-1. Thus, persistent TCR engagement by peptide-MHC class II on thymic medullary stroma inhibits reactivity to self-Ags and prevents autoreactivity in the mature repertoire.
Collapse
Affiliation(s)
- Tom Li Stephen
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | | | | | |
Collapse
|
36
|
KURNIK K, BIDLINGMAIER C, ENGL W, CHEHADEH H, REIPERT B, AUERSWALD G. New early prophylaxis regimen that avoids immunological danger signals can reduce FVIII inhibitor development. Haemophilia 2009; 16:256-62. [DOI: 10.1111/j.1365-2516.2009.02122.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
37
|
Kosmrlj A, Chakraborty AK, Kardar M, Shakhnovich EI. Thymic selection of T-cell receptors as an extreme value problem. PHYSICAL REVIEW LETTERS 2009; 103:068103. [PMID: 19792616 DOI: 10.1103/physrevlett.103.068103] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Indexed: 05/28/2023]
Abstract
T lymphocytes (T cells) orchestrate adaptive immune responses upon activation. T-cell activation requires sufficiently strong binding of T-cell receptors on their surface to short peptides (p) derived from foreign proteins, which are bound to major histocompatibility gene products (displayed on antigen-presenting cells). A diverse and self-tolerant T-cell repertoire is selected in the thymus. We map thymic selection processes to an extreme value problem and provide an analytic expression for the amino acid compositions of selected T-cell receptors (which enable its recognition functions).
Collapse
Affiliation(s)
- Andrej Kosmrlj
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | | | | |
Collapse
|
38
|
Guimont-Desrochers F, Beauchamp C, Chabot-Roy G, Dugas V, Hillhouse EE, Dusseault J, Langlois G, Gautier-Ethier P, Darwiche J, Sarfati M, Lesage S. Absence of CD47 in vivo influences thymic dendritic cell subset proportions but not negative selection of thymocytes. Int Immunol 2009; 21:167-77. [PMID: 19147837 DOI: 10.1093/intimm/dxn135] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CD47 is a ubiquitously expressed molecule which has been attributed a role in many cellular processes. Its role in preventing cellular phagocytosis has defined CD47 as an obligatory self-molecule providing a 'don't-eat-me-signal'. Additionally, CD47-CD172a interactions are important for cellular trafficking. Yet, the contribution of CD47 to T cell stimulation remains controversial, acting sometimes as a co-stimulator and sometimes as an inhibitor of TCR signalling or peripheral T cell responses. Most of the experiments leading to this controversy have been carried in in vitro systems. Moreover, the role of CD47 on thymocyte differentiation, which precisely relies on TCR signal strength, has not been evaluated. Here, we examine the in vivo role of CD47 in T cell differentiation using CD47-deficient mice. We find that, in the absence of CD47, thymocyte positive and negative selection processes are not altered. Indeed, our data demonstrate that the absence of CD47 does not influence the strength of TCR signalling in thymocytes. Furthermore, in agreement with a role for CD47-CD172a interactions in CD172a(+) dendritic cell migration, we report a reduced proportion of thymic dendritic cells expressing CD172a in CD47-deficient mice. As the total proportion of dendritic cells is maintained, this creates an imbalance in the proportion of CD172a(+) and CD172a(low) dendritic cells in the thymus. Together, these data indicate that the altered proportion of thymic dendritic cell subsets does not have a primordial influence on thymic selection processes.
Collapse
Affiliation(s)
- Fanny Guimont-Desrochers
- Research Centre, Maisonneuve-Rosemont Hospital, Department of Microbiology and Immunology, University of Montreal, Montreal, Quebec, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
How the thymus designs antigen-specific and self-tolerant T cell receptor sequences. Proc Natl Acad Sci U S A 2008; 105:16671-6. [PMID: 18946038 DOI: 10.1073/pnas.0808081105] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
T lymphocytes (T cells) orchestrate adaptive immune responses that clear pathogens from infected hosts. T cells recognize short peptides (p) derived from antigenic proteins bound to protein products of the MHC genes. Recognition occurs when T cell receptor (TCR) proteins expressed on T cells bind sufficiently strongly to antigen-derived pMHC complexes on the surface of antigen-presenting cells. A diverse repertoire of self-pMHC-tolerant TCR sequences is shaped during development of T cells in the thymus by processes called positive and negative selection. Combining computational models and analysis of experimental data, we parsed the contributions of positive and negative selection to the design of TCR sequences that recognize antigenic peptides with specificity, yet also exhibit cross-reactivity. A dominant role for negative selection in mediating antigen specificity of mature T cells and a molecular mechanism for TCR recognition of antigen are described.
Collapse
|
40
|
Gavanescu I, Benoist C, Mathis D. B cells are required for Aire-deficient mice to develop multi-organ autoinflammation: A therapeutic approach for APECED patients. Proc Natl Acad Sci U S A 2008; 105:13009-14. [PMID: 18755889 PMCID: PMC2529049 DOI: 10.1073/pnas.0806874105] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Indexed: 12/25/2022] Open
Abstract
Autoimmune regulator (Aire)-deficient mice and humans have circulating autoantibodies against a multitude of organs and multiorgan autoinflammatory infiltrates. It is not known to what extent autoantibodies or their source, B lymphocytes, are required for disease onset or progression. We show in this research that B cells must be present for Aire-deficient mice to develop fulminant infiltrates. We found no evidence that autoantibodies were directly pathogenic; rather, B cells appeared to play a critical early role in T cell priming or expansion. A therapeutic reagent directed against B cells, Rituximab, induced remission of the autoimmune disease in Aire-deficient mice, raising the hope of applying it to human patients with autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).
Collapse
Affiliation(s)
- Irina Gavanescu
- Research Division, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| | - Christophe Benoist
- Research Division, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| | - Diane Mathis
- Research Division, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215
| |
Collapse
|
41
|
Purcell AW, van Driel IR, Gleeson PA. Impact of glycans on T-cell tolerance to glycosylated self-antigens. Immunol Cell Biol 2008; 86:574-9. [PMID: 18626489 DOI: 10.1038/icb.2008.48] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There is now substantial evidence that antigen post-translational modifications are recognized by T cells, and alterations in epitope modification has been linked to a number of autoimmune diseases. An estimated one third of the MHC ligands contain post-translational modification of epitopes. A common post-translational modification of proteins is glycosylation and it is predicted on theoretical grounds that approximately 1-5% of MHC ligands may bear a glycan. From numerous studies over the past 15 years it is clear that glycans can influence T cell responses either by contribution to the structure of the epitope or by influencing the profile of peptide epitopes presented by APCs. The influence of glycans on antigen processing and T cell recognition has particular relevance to the induction of tolerance to self-antigens. Here we discuss the potential impact of glycans on the profile of self-epitopes presented by APCs and the consequence of changes in glycosylation to generate neo self-epitopes resulting in the loss of tolerance and the development of autoimmune diseases. With the recent developments in profiling T cell epitopes, and with strategies for modulating glycosylation in vivo, it is now feasible to directly examine the global influence of glycans on self-tolerance and autoimmunity.
Collapse
Affiliation(s)
- Anthony W Purcell
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, Australia
| | | | | |
Collapse
|
42
|
Hossain MZ, Yu Q, Xu M, Sen JM. ICAT expression disrupts beta-catenin-TCF interactions and impairs survival of thymocytes and activated mature T cells. Int Immunol 2008; 20:925-35. [PMID: 18511409 DOI: 10.1093/intimm/dxn051] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
T cell factor (TCF) family of transcription factors and beta-catenin critically regulate T cell development as demonstrated by the deletion of the tcf gene, which results in a block early in development that becomes complete in mice bearing tcf/lef double deletion. However, the role of beta-catenin, a major TCF cofactor, remains controversial. To directly address this, we have generated transgenic mice expressing Inhibitor of beta-catenin and TCF (ICAT), a naturally occurring inhibitor that specifically disrupts TCF and beta-catenin interactions. In this report, we demonstrate that disrupting the interaction of beta-catenin with TCF renders adult thymocytes and activated T cells highly susceptible to apoptosis. In contrast to previously reported observations during fetal thymocyte development, these data show that in adult mice, survival and not differentiation of thymocytes, depends on transcription by TCF and beta-catenin. Indeed, we demonstrate that expression of ICAT impedes thymocyte survival by reducing the expression of Bcl(xL) in thymocytes below a critical threshold. Survival of activated mature T cells was also impaired due to diminished expression of activation-induced Bcl(xL). Accordingly, expression of transgenic Bcl-2 rescued activated ICAT-Tg CD4 T cells from apoptosis. Thus, disruption of TCF-beta-catenin interactions specifically impairs the survival of thymocytes and activated T cells.
Collapse
Affiliation(s)
- M Zulfiquer Hossain
- Lymphocyte Development Unit, Laboratory of Immunology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | | | | | | |
Collapse
|
43
|
Hogan TV, Ang DKY, Gleeson PA, van Driel IR. Extrathymic mechanisms of T cell tolerance: lessons from autoimmune gastritis. J Autoimmun 2008; 31:268-73. [PMID: 18499395 DOI: 10.1016/j.jaut.2008.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
While the thymus plays a key role in the prevention of many autoimmune phenomena it is clear that robust mechanisms external to the thymus are also vital in controlling self-reactive T cells. Here we review the current concepts in the field of extrathymic tolerance and use recent studies of autoimmune gastritis to illustrate how T cells directed to a prominent, clinically relevant autoantigen, namely the gastric proton pump, can be silenced with little or no thymic involvement. Autoimmune gastritis represents one of the most thoroughly characterised autoimmune systems and the knowledge and tools available to study this disease will continue to allow a thorough assessment of the genetic, cellular and molecular events that underlie tolerance and autoimmunity.
Collapse
Affiliation(s)
- Thea V Hogan
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | | | | |
Collapse
|
44
|
Scott FL, Fuchs GJ, Boyd SE, Denault JB, Hawkins CJ, Dequiedt F, Salvesen GS. Caspase-8 cleaves histone deacetylase 7 and abolishes its transcription repressor function. J Biol Chem 2008; 283:19499-510. [PMID: 18458084 DOI: 10.1074/jbc.m800331200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Caspase-8 is the initiator caspase of the extrinsic apoptosis pathway and also has a role in non-apoptotic physiologies. Identifying endogenous substrates for caspase-8 by using integrated bioinformatics and biological approaches is required to delineate the diverse roles of this caspase. We describe a number of novel putative caspase-8 substrates using the Prediction of Protease Specificity (PoPS) program, one of which is histone deacetylase 7 (HDAC7). HDAC7 is cleaved faster than any other caspase-8 substrate described to date. It is also cleaved in primary CD4+CD8+ thymocytes undergoing extrinsic apoptosis. By using naturally occurring caspase inhibitors that have evolved exquisite specificity at concentrations found within the cell, we could unequivocally assign the cleavage activity to caspase-8. Importantly, cleavage of HDAC7 alters its subcellular localization and abrogates its Nur77 repressor function. Thus we demonstrate a direct role for initiator caspase-mediated proteolysis in promoting gene transcription.
Collapse
Affiliation(s)
- Fiona L Scott
- Program in Apoptosis and Cell Death Research, Burnham Institute for Medical Research, La Jolla, California 92037, USA.
| | | | | | | | | | | | | |
Collapse
|
45
|
Schwartz M, Ziv Y. Immunity to self and self-maintenance: a unified theory of brain pathologies. Trends Immunol 2008; 29:211-9. [DOI: 10.1016/j.it.2008.01.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 01/05/2008] [Accepted: 01/09/2008] [Indexed: 10/22/2022]
|
46
|
Petrich de Marquesini LG, Moustakas AK, Thomas IJ, Wen L, Papadopoulos GK, Wong FS. Functional inhibition related to structure of a highly potent insulin-specific CD8 T cell clone using altered peptide ligands. Eur J Immunol 2008; 38:240-9. [PMID: 18157812 PMCID: PMC2901522 DOI: 10.1002/eji.200737762] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Insulin-reactive CD8 T cells are amongst the earliest islet-infiltrating CD8 T cells in NOD mice. Cloned insulin B15–23-reactive cells (designated G9C8), restricted by H-2Kd, are highly diabetogenic. We used altered peptide ligands (APL) substituted at TCR contact sites, positions (p)6 and 8, to investigate G9C8 T cell function and correlated this with structure. Cytotoxicity and IFN-γ production assays revealed that p6G and p8R could not be replaced by any naturally occurring amino acid without abrogating recognition and functional response by the G9C8 clone. When tested for antagonist activity with APL differing from the native peptide at either of these positions, the peptide variants, G6H and R8L showed the capacity to reduce the agonist response to the native peptide. The antagonist activity in cytotoxicity and IFN-γ production assays can be correlated with conformational changes induced by different structures of the MHC-peptide complexes, shown by molecular modeling. We conclude that p6 and p8 of the insulin B15–23 peptide are very important for TCR stimulation of this clone and no substitutions are tolerated at these positions in the peptide. This is important in considering the therapeutic use of peptides as APL that encompass both CD4 and CD8 epitopes of insulin.
Collapse
|
47
|
Asano A, Tsubomatsu K, Jung CG, Sasaki N, Agui T. A deletion mutation of the protein tyrosine phosphatase kappa (Ptprk) gene is responsible for T-helper immunodeficiency (thid) in the LEC rat. Mamm Genome 2007; 18:779-86. [PMID: 17909891 DOI: 10.1007/s00335-007-9062-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Accepted: 08/13/2007] [Indexed: 11/24/2022]
Abstract
Bone marrow (BM)-derived T-cell progenitors differentiate into CD4 or CD8 single-positive (SP) cells in the thymus. We have previously reported that a single autosomal mutation, thid, causes a defect in the maturation of CD4 SP thymocytes and an abnormality of peripheral helper T cells in the LEC rat. In this study we attempted to identify a gene responsible for the thid mutation. We first performed genetic linkage analysis and mapped the thid locus between Myb and D1Rat392 on Chr 1. In this region we found an approximately 380-kb deletion from intron 3 of the Ptprk gene, which encodes a receptor-like protein tyrosine phosphatase type kappa (RPTPkappa) to intron 1 of the RGD1560849 predicted gene in the LEC rat genome. Reconstitution with syngenic BM cells transduced Ptprk but not the RGD1560849 predicted gene rescued development of CD4 SP cells in the LEC rat thymus. It is confirmed by this result that the Ptprk gene is responsible for the thid mutation in the LEC rat. Our results further suggest that RPTPkappa plays a critical role in the development of CD4 SP cells in the thymus.
Collapse
Affiliation(s)
- Atsushi Asano
- Laboratory of Experimental Animal Science, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo 060-0818, Japan
| | | | | | | | | |
Collapse
|
48
|
Abstract
In the last decade, the identification of enzymes that regulate acetylation of histones and nonhistone proteins has revealed the key role of dynamic acetylation and deacetylation in various cellular processes. Mammalian histone deacetylases (HDACs), which catalyse the removal of acetyl groups from lysine residues, are grouped into three classes, on the basis of similarity to yeast counterparts. An abundance of experimental evidence has established class IIa HDACs as crucial transcriptional regulators of various developmental and differentiation processes. In the past 5 years, a tremendous effort has been dedicated to characterizing the regulation of these enzymes. In this review, we summarize the latest discoveries in the field and discuss the molecular and structural determinants of class IIa HDACs regulation. Finally, we emphasize that comprehension of the mechanisms underlying class IIa HDAC functions is essential for potential therapeutic applications.
Collapse
Affiliation(s)
- M Martin
- Cellular and Molecular Biology Unit, FUSAGx, Gembloux, Belgium
| | | | | |
Collapse
|
49
|
Liblau R, Cassan C. Tolérance immunitaire vis-à-vis d’auto-antigènes du système nerveux : implications thérapeutiques. Rev Neurol (Paris) 2007. [DOI: 10.1016/s0035-3787(07)92155-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
50
|
Xu G, Zhang Y, Zhang L, Ren G, Shi Y. The role of IL-6 in inhibition of lymphocyte apoptosis by mesenchymal stem cells. Biochem Biophys Res Commun 2007; 361:745-50. [PMID: 17678624 PMCID: PMC2699935 DOI: 10.1016/j.bbrc.2007.07.052] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Accepted: 07/12/2007] [Indexed: 12/20/2022]
Abstract
Mesenchymal stem cells (MSCs) are widely distributed throughout the body. Despite intensive studies on the immunosuppressive effect of MSCs, little is known about whether MSCs affect lymphocyte apoptosis. We investigated the effect of MSCs on the spontaneous death of lymphocytes and found that MSCs inhibit the apoptosis of splenocytes and thymocytes as well as purified T and B cells. The protective effect of MSCs was absent when lymphocytes were not in contact with MSCs, indicating that the anti-apoptotic effect is exerted through direct interaction between MSCs and lymphocytes. Interestingly, this anti-apoptotic effect could be inhibited by neutralization of IL-6. Consequently, we found that the expression of IL-6 by MSCs was augmented by contact with lymphocytes. Taken together, these results demonstrate that IL-6 plays an important role in the inhibition of lymphocyte apoptosis by MSCs.
Collapse
Affiliation(s)
| | | | | | | | - Yufang Shi
- Address Correspondence to: Yufang Shi, Ph.D., Department of Molecular Genetics, Microbiology and Immunology, Robert Wood Johnson Medical School, 661 Hoes Lane, Piscataway, NJ 08854, Telephone: (732) 235 4501; Fax: (732) 325 4505, e-mail:
| |
Collapse
|