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  1. Article ; Online: CD8 T-cell heterogeneity during T-cell exhaustion and PD-1-targeted immunotherapy.

    Ando, Satomi / Araki, Koichi

    International immunology

    2022  Volume 34, Issue 11, Page(s) 571–577

    Abstract: Persistent antigenic stimulation results in loss of effector function or physical deletion of antigen-specific CD8 T cells. This T-cell state is called T-cell exhaustion and occurs during chronic infection and cancer. Antigen-specific CD8 T cells during ... ...

    Abstract Persistent antigenic stimulation results in loss of effector function or physical deletion of antigen-specific CD8 T cells. This T-cell state is called T-cell exhaustion and occurs during chronic infection and cancer. Antigen-specific CD8 T cells during T-cell exhaustion express the inhibitory receptor PD-1, the expression of which plays a major role in T-cell dysfunction. PD-1 blockade re-invigorates CD8 T-cell immunity and has been proven effective against many different types of human cancer. To further improve the efficacy of PD-1-targeted immunotherapy in cancer patients, a better understanding of T-cell exhaustion is required. Recent studies have revealed that antigen-specific CD8 T cells during T-cell exhaustion are heterogeneous and have also uncovered the detailed mechanisms for PD-1-targeted immunotherapy. Here, we review the CD8 T-cell subsets that arise during T-cell exhaustion, the lineage relationship among these individual subsets and the role of each subset in PD-1 blockade. Also, we discuss potential strategies to enhance the efficacy of PD-1-targeted immunotherapy.
    MeSH term(s) Antigens/metabolism ; CD8-Positive T-Lymphocytes ; Humans ; Immunologic Factors ; Immunotherapy ; Neoplasms ; Programmed Cell Death 1 Receptor ; T-Lymphocyte Subsets
    Chemical Substances Antigens ; Immunologic Factors ; Programmed Cell Death 1 Receptor
    Language English
    Publishing date 2022-07-28
    Publishing country England
    Document type Journal Article ; Review ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1013745-2
    ISSN 1460-2377 ; 0953-8178
    ISSN (online) 1460-2377
    ISSN 0953-8178
    DOI 10.1093/intimm/dxac038
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Cytokine-Mediated Regulation of CD8 T-Cell Responses During Acute and Chronic Viral Infection.

    Hashimoto, Masao / Im, Se Jin / Araki, Koichi / Ahmed, Rafi

    Cold Spring Harbor perspectives in biology

    2019  Volume 11, Issue 1

    Abstract: The common γ-chain cytokines, interleukin (IL)-2, IL-7, and IL-15, regulate critical aspects of antiviral CD8 T-cell responses. During acute infections, IL-2 controls expansion and differentiation of antiviral CD8 T cells, whereas IL-7 and IL-15 are key ... ...

    Abstract The common γ-chain cytokines, interleukin (IL)-2, IL-7, and IL-15, regulate critical aspects of antiviral CD8 T-cell responses. During acute infections, IL-2 controls expansion and differentiation of antiviral CD8 T cells, whereas IL-7 and IL-15 are key cytokines to maintain memory CD8 T cells long term in an antigen-independent manner. On the other hand, during chronic infections, in which T-cell exhaustion is established, precise roles of these cytokines in regulation of antiviral CD8 T-cell responses are not well defined. Nonetheless, administration of IL-2, IL-7, or IL-15 can increase function of exhausted CD8 T cells, and thus can be an attractive therapeutic approach. A new subset of stem-cell-like CD8 T cells, which provides a proliferative burst after programmed cell death (PD)-1 therapy, has been recently described during chronic viral infection. Further understanding of cytokine-mediated regulation of this CD8 T-cell subset will improve cytokine therapies to treat chronic infections and cancer in combination with immune checkpoint inhibitors.
    MeSH term(s) Animals ; Antiviral Agents/pharmacology ; CD8-Positive T-Lymphocytes/cytology ; CD8-Positive T-Lymphocytes/virology ; Cell Differentiation ; Humans ; Immune System ; Immunologic Memory ; Immunotherapy ; Interleukin-15/immunology ; Interleukin-2/immunology ; Interleukin-7/immunology ; Lymphocyte Activation ; Programmed Cell Death 1 Receptor/immunology ; Stem Cells/cytology ; Virus Diseases/immunology
    Chemical Substances Antiviral Agents ; IL15 protein, human ; IL2 protein, human ; IL7 protein, human ; Interleukin-15 ; Interleukin-2 ; Interleukin-7 ; PDCD1 protein, human ; Programmed Cell Death 1 Receptor
    Language English
    Publishing date 2019-01-02
    Publishing country United States
    Document type Journal Article ; Review
    ISSN 1943-0264
    ISSN (online) 1943-0264
    DOI 10.1101/cshperspect.a028464
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Mitochondrial metabolic flexibility is critical for CD8

    Chen, Chao / Zheng, Hong / Horwitz, Edwin M / Ando, Satomi / Araki, Koichi / Zhao, Peng / Li, Zhiguo / Ford, Mandy L / Ahmed, Rafi / Qu, Cheng-Kui

    Science advances

    2023  Volume 9, Issue 49, Page(s) eadf9522

    Abstract: Mitochondria use different substrates for energy production and intermediatory metabolism according to the availability of nutrients and oxygen levels. The role of mitochondrial metabolic flexibility for ... ...

    Abstract Mitochondria use different substrates for energy production and intermediatory metabolism according to the availability of nutrients and oxygen levels. The role of mitochondrial metabolic flexibility for CD8
    MeSH term(s) PTEN Phosphohydrolase/metabolism ; Mitochondria/metabolism ; Apoptosis ; Cell Differentiation ; CD8-Positive T-Lymphocytes/metabolism
    Chemical Substances PTEN Phosphohydrolase (EC 3.1.3.67)
    Language English
    Publishing date 2023-12-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2810933-8
    ISSN 2375-2548 ; 2375-2548
    ISSN (online) 2375-2548
    ISSN 2375-2548
    DOI 10.1126/sciadv.adf9522
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: mTOR regulates T cell exhaustion and PD-1-targeted immunotherapy response during chronic viral infection.

    Ando, Satomi / Perkins, Charles M / Sajiki, Yamato / Chastain, Chase / Valanparambil, Rajesh M / Wieland, Andreas / Hudson, William H / Hashimoto, Masao / Ramalingam, Suresh S / Freeman, Gordon J / Ahmed, Rafi / Araki, Koichi

    The Journal of clinical investigation

    2023  Volume 133, Issue 2

    Abstract: T cell exhaustion is a state of T cell dysfunction associated with expression of programmed death 1 (PD-1). Exhausted CD8+ T cells are maintained by self-renewing stem-like T cells that provide differentiated TIM3+ cells, a part of which possesses ... ...

    Abstract T cell exhaustion is a state of T cell dysfunction associated with expression of programmed death 1 (PD-1). Exhausted CD8+ T cells are maintained by self-renewing stem-like T cells that provide differentiated TIM3+ cells, a part of which possesses effector-like properties. PD-1-targeted therapies enhance T cell response by promoting differentiation of stem-like T cells toward TIM3+ cells, but the role of mTOR during T cell exhaustion remains elusive. Here, we showed that mTOR inhibition has distinct outcomes during the beginning of and after the establishment of chronic viral infection. Blocking mTOR during the T cell expansion phase enhanced the T cell response by causing accumulation of stem-like T cells, leading to improved efficacy of PD-1 immunotherapy; whereas, after exhaustion progressed, mTOR inhibition caused immunosuppression, characterized by decreased TIM3+ cells and increased viral load with minimal changes in stem-like T cells. Mechanistically, a cell-intrinsic mTOR signal was vital for differentiation of stem-like T cells into the TIM3+ state in the early and late phases of chronic infection as well as during PD-1 immunotherapy. Thus, PD-1 blockade worked after cessation of mTOR inhibition, but simultaneous treatment failed to induce functional TIM3+ cells, reducing efficacy of PD-1 immunotherapy. Our data demonstrate that mTOR regulates T cell exhaustion and have important implications for combination cancer therapies with PD-1 blockade.
    MeSH term(s) CD8-Positive T-Lymphocytes/metabolism ; Hepatitis A Virus Cellular Receptor 2/genetics ; Hepatitis A Virus Cellular Receptor 2/metabolism ; Immunotherapy ; Persistent Infection ; Programmed Cell Death 1 Receptor/genetics ; Programmed Cell Death 1 Receptor/metabolism ; T-Cell Exhaustion ; TOR Serine-Threonine Kinases/genetics ; TOR Serine-Threonine Kinases/metabolism ; Virus Diseases/metabolism
    Chemical Substances Hepatitis A Virus Cellular Receptor 2 ; Programmed Cell Death 1 Receptor ; TOR Serine-Threonine Kinases (EC 2.7.11.1)
    Language English
    Publishing date 2023-01-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 3067-3
    ISSN 1558-8238 ; 0021-9738
    ISSN (online) 1558-8238
    ISSN 0021-9738
    DOI 10.1172/JCI160025
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: AMPK: a metabolic switch for CD8+ T-cell memory.

    Araki, Koichi / Ahmed, Rafi

    European journal of immunology

    2013  Volume 43, Issue 4, Page(s) 878–881

    Abstract: Adenosine monophosphate-activated protein kinase (AMPK) is a serine/threonine kinase and is crucial for cellular energy homeostasis. The exact role of AMPK during memory CD8(+) T-cell differentiation, a process that changes from the metabolically active ... ...

    Abstract Adenosine monophosphate-activated protein kinase (AMPK) is a serine/threonine kinase and is crucial for cellular energy homeostasis. The exact role of AMPK during memory CD8(+) T-cell differentiation, a process that changes from the metabolically active state of effector T cells to one of quiescence in memory cells is not well understood; however, a report by Cantrell and colleagues [Eur. J. Immunol. 2013. 43: 889-896] in this issue of the European Journal of Immunology shows that AMPK, by sensing glucose stress, is an important upstream molecule of mammalian target of rapamycin (mTOR) complex 1 for memory CD8(+) T-cell differentiation. This study provides new insights into how AMPK monitors energy stress to control effector and memory CD8(+) T-cell formation as discussed in this Commentary.
    MeSH term(s) AMP-Activated Protein Kinases/metabolism ; Animals ; CD8-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/metabolism ; Glucose/metabolism ; Immunologic Memory
    Chemical Substances AMPK alpha1 subunit, mouse (EC 2.7.11.1) ; AMP-Activated Protein Kinases (EC 2.7.11.31) ; Glucose (IY9XDZ35W2)
    Language English
    Publishing date 2013-03-16
    Publishing country Germany
    Document type Journal Article ; Comment
    ZDB-ID 120108-6
    ISSN 1521-4141 ; 0014-2980
    ISSN (online) 1521-4141
    ISSN 0014-2980
    DOI 10.1002/eji.201343483
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Utilizing a retroviral RNAi system to investigate in vivo mTOR functions in T cells.

    Araki, Koichi / Konieczny, Bogumila T

    Methods in molecular biology (Clifton, N.J.)

    2012  Volume 821, Page(s) 305–316

    Abstract: RNA interference (RNAi) is an intracellular mechanism for silencing gene expression utilizing short fragments of double-strand RNA that are complementary to the target messenger RNA. This gene silencing technique has now become an invaluable research ... ...

    Abstract RNA interference (RNAi) is an intracellular mechanism for silencing gene expression utilizing short fragments of double-strand RNA that are complementary to the target messenger RNA. This gene silencing technique has now become an invaluable research tool due to its specific and strong repressive effect on a target transcript. We have recently applied a retrovirus-based RNAi system to investigate the in vivo role of the mammalian target of rapamycin (mTOR) in antigen-specific CD8 T cells, and have found that mTOR regulates memory CD8 T-cell differentiation. Here, we provide a detailed protocol for knocking down mTOR and its related molecules (raptor and FKBP12) in antigen-specific CD8 T cells. In our protocol, a mouse model of lymphocytic choriomeningitis virus infection is used, but the methods can be extended to other viral and bacterial infections as well as vaccinations. Also, the similar approach can be applied to analysis of CD4 T-cell responses.
    MeSH term(s) Adaptor Proteins, Signal Transducing ; Animals ; CD8-Positive T-Lymphocytes/cytology ; CD8-Positive T-Lymphocytes/immunology ; Carrier Proteins/genetics ; Carrier Proteins/metabolism ; Cell Differentiation ; Cell Line ; Disease Models, Animal ; Flow Cytometry ; Gene Expression Regulation ; Gene Knockdown Techniques ; Gene Silencing/immunology ; Genetic Vectors ; Humans ; Immunity, Innate/genetics ; Lymphocytic Choriomeningitis/genetics ; Lymphocytic Choriomeningitis/metabolism ; Lymphocytic Choriomeningitis/virology ; Mice ; Mice, Inbred C57BL ; RNA Interference ; Regulatory-Associated Protein of mTOR ; Retroviridae ; TOR Serine-Threonine Kinases/genetics ; TOR Serine-Threonine Kinases/immunology ; Tacrolimus Binding Protein 1A/genetics ; Tacrolimus Binding Protein 1A/metabolism ; Transduction, Genetic
    Chemical Substances Adaptor Proteins, Signal Transducing ; Carrier Proteins ; Regulatory-Associated Protein of mTOR ; Rptor protein, mouse ; TOR Serine-Threonine Kinases (EC 2.7.1.1) ; Tacrolimus Binding Protein 1A (EC 5.2.1.-)
    Language English
    Publishing date 2012
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-61779-430-8_19
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: PD-1 blockade increases the self-renewal of stem-like CD8 T cells to compensate for their accelerated differentiation into effectors.

    Gill, Amanda L / Wang, Peter H / Lee, Judong / Hudson, William H / Ando, Satomi / Araki, Koichi / Hu, Yinghong / Wieland, Andreas / Im, Sejin / Gavora, Autumn / Medina, Christopher B / Freeman, Gordon J / Hashimoto, Masao / Reiner, Steven L / Ahmed, Rafi

    Science immunology

    2023  Volume 8, Issue 86, Page(s) eadg0539

    Abstract: ... PD- ... ...

    Abstract PD-1
    MeSH term(s) Humans ; Animals ; Mice ; Programmed Cell Death 1 Receptor ; CD8-Positive T-Lymphocytes ; Antibodies ; Cell Differentiation ; Disease Models, Animal
    Chemical Substances Programmed Cell Death 1 Receptor ; Antibodies
    Language English
    Publishing date 2023-08-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ISSN 2470-9468
    ISSN (online) 2470-9468
    DOI 10.1126/sciimmunol.adg0539
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Beyond adjuvants: immunomodulation strategies to enhance T cell immunity.

    Kamphorst, Alice O / Araki, Koichi / Ahmed, Rafi

    Vaccine

    2015  Volume 33 Suppl 2, Page(s) B21–8

    Abstract: Engagement of CD8T cells is a crucial aspect of immune responses to pathogens and in tumor surveillance. Nonetheless most vaccination strategies with common adjuvants fail to elicit long-term memory CD8T cells. Increased knowledge on the cellular and ... ...

    Abstract Engagement of CD8T cells is a crucial aspect of immune responses to pathogens and in tumor surveillance. Nonetheless most vaccination strategies with common adjuvants fail to elicit long-term memory CD8T cells. Increased knowledge on the cellular and molecular requirements for CD8T cell activation has unveiled new opportunities to directly modulate CD8T cells to generate optimal responses. During chronic infections and cancer, immunomodulation strategies to enhance T cell responses may be particularly necessary to overcome the immunosuppressive microenvironment. In this review we will discuss blockade of inhibitory receptors; interleukin-2 administration; regulatory T cell modulation; and targeting of mTOR, as means to enhance CD8T cell immunity.
    MeSH term(s) Adaptive Immunity ; CD8-Positive T-Lymphocytes/immunology ; Humans ; Immunologic Memory ; Immunomodulation ; Interleukin-2/metabolism ; T-Lymphocytes, Regulatory/immunology ; TOR Serine-Threonine Kinases/metabolism
    Chemical Substances Interleukin-2 ; TOR Serine-Threonine Kinases (EC 2.7.1.1)
    Language English
    Publishing date 2015-06-08
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 605674-x
    ISSN 1873-2518 ; 0264-410X
    ISSN (online) 1873-2518
    ISSN 0264-410X
    DOI 10.1016/j.vaccine.2014.12.082
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Programmed cell death 1-directed immunotherapy for enhancing T-cell function.

    Araki, Koichi / Youngblood, Ben / Ahmed, Rafi

    Cold Spring Harbor symposia on quantitative biology

    2013  Volume 78, Page(s) 239–247

    Abstract: T-cell exhaustion is a unique state that appears during many chronic infections and cancer and is characterized by loss of proliferative capacity and effector function. Complex mechanisms are involved in this T-cell dysfunction but an inhibitory receptor, ...

    Abstract T-cell exhaustion is a unique state that appears during many chronic infections and cancer and is characterized by loss of proliferative capacity and effector function. Complex mechanisms are involved in this T-cell dysfunction but an inhibitory receptor, PD-1, has been identified as a major regulator of T-cell exhaustion. Blockade of the PD-1 pathway can reinvigorate exhausted T cells, resulting in better control of chronic infections and cancer. Notably, recent clinical studies have revealed that PD-1-directed immunotherapy is highly effective in cancer patients, demonstrating that PD-1 is a promising therapeutic target in humans. In this review, we summarize our current understanding of the epigenetic regulation of PD-1 expression in T cells and discuss potential combination therapy with PD-1 blockade toward developing more effective treatment for chronic infections and cancer.
    MeSH term(s) Animals ; Apoptosis Regulatory Proteins/metabolism ; CD8-Positive T-Lymphocytes/cytology ; Cell Death ; Cytokines/metabolism ; DNA Methylation ; Epigenesis, Genetic ; Gene Expression Regulation ; Humans ; Immunotherapy/methods ; Infection/immunology ; Mice ; Neoplasms/immunology ; Programmed Cell Death 1 Receptor/immunology ; Signal Transduction ; T-Lymphocytes/cytology ; T-Lymphocytes/immunology
    Chemical Substances Apoptosis Regulatory Proteins ; Cytokines ; Programmed Cell Death 1 Receptor
    Language English
    Publishing date 2013
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ISSN 1943-4456 ; 0091-7451
    ISSN (online) 1943-4456
    ISSN 0091-7451
    DOI 10.1101/sqb.2013.78.019869
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: mTOR, linking metabolism and immunity.

    Xu, Xiaojin / Ye, Lilin / Araki, Koichi / Ahmed, Rafi

    Seminars in immunology

    2013  Volume 24, Issue 6, Page(s) 429–435

    Abstract: mTOR is an evolutionarily conserved serine/threonine kinase that plays a critical role in cell growth and metabolism by sensing different environmental cues. There is a growing appreciation of mTOR in immunology for its role in integrating diverse ... ...

    Abstract mTOR is an evolutionarily conserved serine/threonine kinase that plays a critical role in cell growth and metabolism by sensing different environmental cues. There is a growing appreciation of mTOR in immunology for its role in integrating diverse signals from the immune microenvironment and coordinating the functions of immune cells and their metabolism. In CD8 T cells, mTOR has shown to influence cellular commitment to effector versus memory programming; in CD4 T cells, mTOR integrates environmental cues that instruct effector cell differentiation. In this review, we summarize and discuss recent advances in the field, with a focus on the mechanisms through which mTOR regulates cellular and humoral immunity. Further understanding will enable the manipulation of mTOR signaling to direct the biological functions of immune cells, which holds great potential for improving immune therapies and vaccination against infections and cancer.
    MeSH term(s) Animals ; B-Lymphocytes/cytology ; B-Lymphocytes/immunology ; B-Lymphocytes/metabolism ; Cell Differentiation ; Humans ; Immunity/immunology ; Signal Transduction ; T-Lymphocytes/cytology ; T-Lymphocytes/immunology ; T-Lymphocytes/metabolism ; TOR Serine-Threonine Kinases/metabolism
    Chemical Substances MTOR protein, human (EC 2.7.1.1) ; TOR Serine-Threonine Kinases (EC 2.7.1.1)
    Language English
    Publishing date 2013-01-24
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 1018141-6
    ISSN 1096-3618 ; 1044-5323
    ISSN (online) 1096-3618
    ISSN 1044-5323
    DOI 10.1016/j.smim.2012.12.005
    Database MEDical Literature Analysis and Retrieval System OnLINE

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