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Abstract
I've had serious misgivings about writing this article, because from living the experience day by day, it's hard to believe my accomplishments merit the attention. To skirt this roadblock, I forced myself to pretend I was in a conversation with my trainees, trying to distill the central driving forces of my career in science. The below chronicles my evolution from would-be astronaut/ballerina to budding developmental biologist to devoted T cell immunologist. It traces my work from a focus on intrathymic events that mold developing T cells into self-major histocompatibility complex (MHC)-restricted lymphocytes to extrathymic events that fine-tune the T cell receptor (TCR) repertoire and impose the finishing touches on T cell maturation. It is a story of a few personal attributes multiplied by generous mentors, good luck, hard work, perseverance, and knowing when to step down. Expected final online publication date for the Annual Review of Immunology, Volume 40 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Pamela J Fink
- Department of Immunology, University of Washington, Seattle, Washington, USA;
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Briceño O, Peralta-Prado A, Garrido-Rodríguez D, Romero-Mora K, Chávez-Torres M, de la Barrera CA, Reyes-Terán G, Ávila-Ríos S. Characterization of CD31 expression in CD4+ and CD8+T cell subpopulations in chronic untreated HIV infection. Immunol Lett 2021; 235:22-31. [PMID: 33852965 DOI: 10.1016/j.imlet.2021.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 03/09/2021] [Accepted: 04/07/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND The platelet endothelial cell adhesion molecule-1 (PECAM-1) or CD31 has been involved in regulation of T-cell tolerance, activation, survival and homing in mice cells. However, there is limited knowledge about the expression pattern and role of this molecule in human T cells, particularly in conditions of chronic immune activation. OBJECTIVES We explored CD31 expression in T cell differentiation subsets of individuals with untreated HIV infection and in non-HIV-infected controls. We also assessed phenotypic differences between CD31+ and CD31- subsets in memory and terminally differentiated (TEMRA) CD4+ and CD8 + T cells. METHODS Forty-one individuals with untreated HIV infection and 34 non-HIV-infected controls were included in the study. We compared the expression of CD31 in CD4+ and CD8 + T cells across stages of differentiation in the two study groups by flow cytometry. We also analyzed the expression of CD57 (a marker of senescence), Ki67 (a marker of cycling cells), PD-1 (a marker of exhaustion), and CD38/HLA-DR (a marker of immune activation) on memory and TEMRA CD31+ and CD31- T cells. RESULTS CD31 expression was significantly higher in CD8 + T cells than in CD4 + T cells, measured as frequency, absolute numbers and median fluorescence intensity (MFI), in both study groups (p < 0.0001 in all cases). Intermediate differentiation subsets of CD4+ and CD8 + T cells expressed higher levels of CD31 in the context of HIV infection (p < 0.001 in all cases). CD31 expression frequency decreased with cellular differentiation of CD4+ and CD8 + T cells in both groups, but this decrease was steeper in individuals without HIV infection (CD4+: p < 0.001 and CD8+: p < 0.0001). As expected, memory and TEMRA CD4+ and CD8 + T cells expressed significantly higher levels of CD57, PD-1, Ki67 and CD38/HLA-DR in HIV-infected compared to non-HIV-infected individuals (p < 0.01 in all cases). CD31 expression was associated with lower activation of memory (but not TEMRA) CD4 + T cells in non-HIV-infected persons, an effect not observed in the HIV-infected group. CD31 expression on memory CD8 + T cells of HIV-infected individuals was associated higher levels of PD-1 (p = 0.0019) and CD38/HLADR (p = 0.0345), and higher PD-1 expression on CD8 + TEMRA (p = 0.0024), an effect not observed in non-HIV-infected individuals. CONCLUSION In the context of HIV-associated chronic immune activation, specifically on memory CD8 + T cells, CD31 expression was associated with higher PD-1 and CD38/HLA-DR co-expression, suggesting that CD31 expression may result from an insufficient attempt to contain T cell exhaustion and activation. CD31-targeted therapies may contribute to modulate these cellular responses.
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Affiliation(s)
- Olivia Briceño
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico.
| | - Amy Peralta-Prado
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Daniela Garrido-Rodríguez
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Karla Romero-Mora
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Monserrat Chávez-Torres
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Claudia-Alvarado de la Barrera
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Gustavo Reyes-Terán
- Coordinating Commission of the Mexican National Institutes of Health, Mexico City, Mexico
| | - Santiago Ávila-Ríos
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
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Cunningham CA, Hoppins S, Fink PJ. Cutting Edge: Glycolytic Metabolism and Mitochondrial Metabolism Are Uncoupled in Antigen-Activated CD8 + Recent Thymic Emigrants. THE JOURNAL OF IMMUNOLOGY 2018; 201:1627-1632. [PMID: 30068595 DOI: 10.4049/jimmunol.1800705] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/13/2018] [Indexed: 01/18/2023]
Abstract
Recent thymic emigrants (RTEs) are peripheral T cells that have most recently completed selection and thymic egress and constitute a population that is phenotypically and functionally distinct from its more mature counterpart. Ag-activated RTEs are less potent effectors than are activated mature T cells, due in part to reduced aerobic glycolysis (correctable by exogenous IL-2), which in turn impacts IFN-γ production. Mitochondria serve as nodal regulators of cell function, but their contribution to the unique biology of RTEs is unknown. In this study, we show that activated mouse RTEs have impaired oxidative phosphorylation, even in the presence of exogenous IL-2. This altered respiratory phenotype is the result of decreased CD28 signaling, reduced glutaminase induction, and diminished mitochondrial mass in RTEs relative to mature T cells. These results suggest an uncoupling whereby IL-2 tunes the rate of RTE glycolytic metabolism, whereas the unique profile of RTE mitochondrial metabolism is "hard wired."
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Affiliation(s)
- Cody A Cunningham
- Department of Immunology, University of Washington, Seattle, WA 98109; and
| | - Suzanne Hoppins
- Department of Biochemistry, University of Washington, Seattle, WA 98195
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109; and
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Cunningham CA, Helm EY, Fink PJ. Reinterpreting recent thymic emigrant function: defective or adaptive? Curr Opin Immunol 2018; 51:1-6. [PMID: 29257954 PMCID: PMC5943149 DOI: 10.1016/j.coi.2017.12.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/06/2017] [Indexed: 11/30/2022]
Abstract
Recent thymic emigrants (RTEs) are those peripheral T cells that have most recently completed thymic development and egress. Over the past decade, significant advances have been made in understanding the cell-extrinsic and cell-intrinsic requirements for RTE maturation to mature naïve (MN) T cells and in detailing the functional differences that characterize these two T cell populations. Much of this work has suggested that RTEs are hypo-functional versions of more mature T cells. However, recent evidence has indicated that rather than being defective T cells, RTEs are exquisitely adapted to their cellular niche. In this review, we argue that RTEs are not flawed mature T cells but are adapted to fill an underpopulated T cell compartment, while maintaining self tolerance and possessing the capacity to mount robust immune responses.
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Affiliation(s)
- Cody A Cunningham
- Department of Immunology, University of Washington, Seattle, WA 98109, United States
| | - Eric Y Helm
- Department of Immunology, University of Washington, Seattle, WA 98109, United States
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109, United States.
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Zhang S, Zhang X, Wang K, Xu X, Li M, Zhang J, Zhang Y, Hao J, Sun X, Chen Y, Liu X, Chang Y, Jin R, Wu H, Ge Q. Newly Generated CD4 + T Cells Acquire Metabolic Quiescence after Thymic Egress. THE JOURNAL OF IMMUNOLOGY 2017; 200:1064-1077. [PMID: 29288207 DOI: 10.4049/jimmunol.1700721] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 11/27/2017] [Indexed: 12/19/2022]
Abstract
Mature naive T cells circulate through the secondary lymphoid organs in an actively enforced quiescent state. Impaired cell survival and cell functions could be found when T cells have defects in quiescence. One of the key features of T cell quiescence is low basal metabolic activity. It remains unclear at which developmental stage T cells acquire this metabolic quiescence. We compared mitochondria among CD4 single-positive (SP) T cells in the thymus, CD4+ recent thymic emigrants (RTEs), and mature naive T cells in the periphery. The results demonstrate that RTEs and naive T cells had reduced mitochondrial content and mitochondrial reactive oxygen species when compared with SP thymocytes. This downregulation of mitochondria requires T cell egress from the thymus and occurs early after young T cells enter the circulation. Autophagic clearance of mitochondria, but not mitochondria biogenesis or fission/fusion, contributes to mitochondrial downregulation in RTEs. The enhanced apoptosis signal-regulating kinase 1/MAPKs and reduced mechanistic target of rapamycin activities in RTEs relative to SP thymocytes may be involved in this mitochondrial reduction. These results indicate that the gain of metabolic quiescence is one of the important maturation processes during SP-RTE transition. Together with functional maturation, it promotes the survival and full responsiveness to activating stimuli in young T cells.
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Affiliation(s)
- Shusong Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xinwei Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Ke Wang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xi Xu
- Center for Molecular Metabolism, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Mingyang Li
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Jun Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Yan Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Jie Hao
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xiuyuan Sun
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Yingyu Chen
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohui Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yingjun Chang
- Peking University Institute of Hematology, People's Hospital, Beijing 100044, China; and
| | - Rong Jin
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; .,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Hounan Wu
- Peking University Medical and Health Analytical Center, Peking University Health Science Center, Beijing 100191, China
| | - Qing Ge
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; .,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
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Cunningham CA, Bergsbaken T, Fink PJ. Cutting Edge: Defective Aerobic Glycolysis Defines the Distinct Effector Function in Antigen-Activated CD8 + Recent Thymic Emigrants. THE JOURNAL OF IMMUNOLOGY 2017; 198:4575-4580. [PMID: 28507025 DOI: 10.4049/jimmunol.1700465] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 04/25/2017] [Indexed: 01/03/2023]
Abstract
Recent thymic emigrants (RTEs) are the youngest peripheral T cells that have completed thymic selection and egress to the lymphoid periphery. RTEs are functionally distinct from their more mature but still naive T cell counterparts, because they exhibit dampened proliferation and reduced cytokine production upon activation. In this article, we show that, compared with more mature but still naive T cells, RTEs are impaired in their ability to perform aerobic glycolysis following activation. Impaired metabolism underlies the reduced IFN-γ production observed in activated RTEs. This failure to undergo Ag-induced aerobic glycolysis is caused by reduced mTORC1 activity and diminished Myc induction in RTEs. Critically, exogenous IL-2 restores Myc expression in RTEs, driving aerobic glycolysis and IFN-γ production to the level of mature T cells. These results reveal a previously unknown metabolic component to postthymic T cell maturation.
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Affiliation(s)
- Cody A Cunningham
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Tessa Bergsbaken
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109
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Moore JWJ, Beattie L, Osman M, Owens BMJ, Brown N, Dalton JE, Maroof A, Kaye PM. CD4+ Recent Thymic Emigrants Are Recruited into Granulomas during Leishmania donovani Infection but Have Limited Capacity for Cytokine Production. PLoS One 2016; 11:e0163604. [PMID: 27658046 PMCID: PMC5033337 DOI: 10.1371/journal.pone.0163604] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/12/2016] [Indexed: 11/19/2022] Open
Abstract
Recent thymic emigrants (RTEs) represent a source of antigen-naïve T cells that enter the periphery throughout life. However, whether RTEs contribute to the control of chronic parasitic infection and how their potential might be harnessed by therapeutic intervention is currently unclear. Here, we show that CD4+ recent thymic emigrants emerging into the periphery of mice with ongoing Leishmania donovani infection undergo partial activation and are recruited to sites of granulomatous inflammation. However, CD4+ RTEs displayed severely restricted differentiation either into IFNγ+ or IFNγ+TNFα+ effectors, or into IL-10-producing regulatory T cells. Effector cell differentiation in the chronically infected host was not promoted by adoptive transfer of activated dendritic cells or by allowing extended periods of post-thymic differentiation in the periphery. Nevertheless, CD4+ RTEs from infected mice retained the capacity to transfer protection into lymphopenic RAG2-/- mice. Taken together, our data indicate that RTEs emerging into a chronically inflamed environment are not recruited into the effector pool, but retain the capacity for subsequent differentiation into host protective T cells when placed in a disease-free environment.
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Affiliation(s)
- John W. J. Moore
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Lynette Beattie
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Mohamed Osman
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Benjamin M. J. Owens
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Najmeeyah Brown
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Jane E. Dalton
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Asher Maroof
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
| | - Paul M. Kaye
- Centre for Immunology & Infection, Department of Biology and Hull York Medical School, University of York, York, United Kingdom
- * E-mail:
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