scholarly journals Abnormal CD8 T cells induce and track Alzheimer’s-like neurodegeneration

2021 ◽  
Author(s):  
Christopher Wheeler ◽  
Akanksha Panwar ◽  
Altan Rentsendorj ◽  
Michelle Jhun ◽  
Robert Cohen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mouse Model ◽  
Cd8 T Cells ◽  
Neurodegenerative Disorder ◽  
Cd8 T Cell ◽  
Cell Aging ◽  
Memory Cd8 T Cells ◽  
Age Related ◽  
The Impact

Abstract Sporadic Alzheimer’s disease, the most common neurodegenerative disorder of aging, is characterized by cerebral plaques and neurofibrillary tangles. Experimental rodents develop plaques but neither tangles nor substantial neurodegeneration under conditions that guarantee Alzheimer’s in humans, suggesting rodents lack critical co-initiation factors. Accumulation of antigen-reactive memory CD8 T cells increases with aging, and was recently revealed as a hallmark of human Alzheimer’s. The impact of this process on disease initiation, however, has not been established because age-related T cell changes are muted in rodents. We developed a mouse model of human-like CD8 T cell aging that promotes antigen-reactive memory CD8 T cell accumulation. Here we show that these “hiT” mice develop all major hallmarks of Alzheimer’s with aging, including tangle-like inclusions and substantial neurodegeneration. Antigen-reactive CD8 T cells analogous to those in hiT mice increased in Alzheimer’s brain, but decreased earlier in blood, where their loss effectively distinguished the Alzheimer’s continuum from aging controls. Our findings establish a clinically relevant mouse model for sporadic Alzheimer’s and show that age-related immune dysfunction critically contributes to its initiation. They also identify useful immune-based targets to track and potentially treat human Alzheimer’s, while validating a model system to examine age-related disease immuno-biology more generally.

scholarly journals Age-Related Decline in Primary CD8+ T Cell Responses Is Associated with the Development of Senescence in Virtual Memory CD8+ T Cells

Cell Reports ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3512-3524 ◽  
Author(s):  
Kylie M. Quinn ◽  
Annette Fox ◽  
Kim L. Harland ◽  
Brendan E. Russ ◽  
Jasmine Li ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Virtual Memory ◽  
Cd8 T Cell ◽  
Memory Cd8 T Cells ◽  
Cell Responses ◽  
Age Related

scholarly journals Superior Protective Immunity against Murine Listeriosis by Combined Vaccination with CpG DNA and Recombinant Salmonella enterica Serovar Typhimurium

2009 ◽  
Vol 77 (12) ◽  
pp. 5501-5508 ◽  
Author(s):  
Christina Berchtold ◽  
Klaus Panthel ◽  
Stefan Jellbauer ◽  
Brigitte Köhn ◽  
Elisabeth Roider ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Salmonella Enterica ◽  
Protective Immunity ◽  
Cd8 T Cell ◽  
Cpg Dna ◽  
Memory Cd8 T Cells ◽  
Type Iii ◽  
Serovar Typhimurium

ABSTRACT Preexisting antivector immunity can severely compromise the ability of Salmonella enterica serovar Typhimurium live vaccines to induce protective CD8 T-cell frequencies after type III secretion system-mediated heterologous protein translocation in orally immunized mice. To circumvent this problem, we injected CpG DNA admixed to the immunodominant p60217-225 peptide from Listeria monocytogenes subcutaneously into BALB/c mice and coadministered a p60-translocating Salmonella strain by the orogastric route. The distribution of tetramer-positive p60217-225-specific effector and memory CD8 T cells was analyzed by costaining of lymphocytes with CD62L and CD127. In contrast to the single oral application of recombinant Salmonella or single immunization with CpG and p60, in the spleens from mice immunized with a combination of both vaccine types a significantly higher level of p60-specific CD8 T cells with a predominance of the effector memory T-cell subset was detected. In vivo protection studies revealed that this CD8 T-cell population conferred sterile protective immunity against a lethal infection with L. monocytogenes. However, p60-specific central memory CD8 T cells induced by single vaccination with CpG and p60 were not able confer effective protection against rapidly replicating intracellular Listeria. In conclusion, we provide compelling evidence that the combination of Salmonella type III-mediated antigen delivery and CpG immunization is an attractive novel vaccination strategy to modulate CD8 differentiation patterns toward distinct antigen-specific T-cell subsets with favorable protective capacities.

scholarly journals Human memory CD8 T cell effector potential is epigenetically preserved during in vivo homeostasis

2017 ◽  
Vol 214 (6) ◽  
pp. 1593-1606 ◽  
Author(s):  
Hossam A. Abdelsamed ◽  
Ardiana Moustaki ◽  
Yiping Fan ◽  
Pranay Dogra ◽  
Hazem E. Ghoneim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Human Memory ◽  
Memory Cd8 T Cells ◽  
Memory Cd8 T Cell ◽  
Cell Effector

Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell–mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (TEM), and longer-lived central memory (TCM) and stem cell memory (TSCM) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7– and IL-15–mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of TCM and TSCM memory cells resulted in phenotypic conversion into TEM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired TEM-associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells.

scholarly journals CD8 T Cells andToxoplasma gondii: A New Paradigm

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jason P. Gigley ◽  
Rajarshi Bhadra ◽  
Imtiaz A. Khan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cytolytic Activity ◽  
New Paradigm ◽  
Memory Cd8 T Cells ◽  
Effector Cells ◽  
Cell Responses ◽  
Immune Pressure

CD8 T cells are essential for control ofToxoplasma gondiiinfection. Once activated they undergo differentiation into short-lived effector and memory precursor effector cells. As effector cells, CD8 T cells exert immune pressure on the parasite via production of inflammatory cytokines and through their cytolytic activity. Once immune control has been established, the parasite encysts and develops into chronic infection regulated by the memory CD8 T-cell population. Several signals are needed for this process to be initiated and for development of fully differentiated memory CD8 T cells. With newly developed tools including CD8 T-cell tetramers and TCR transgenic mice, dissecting the biology behindT. gondii-specific CD8 T-cell responses can now be more effectively addressed. In this paper, we discuss what is known about the signals required for effectiveT. gondii-specific CD8 T-cell development, their differentiation, and effector function.

scholarly journals PD-1 is a regulator of virus-specific CD8+ T cell survival in HIV infection

2006 ◽  
Vol 203 (10) ◽  
pp. 2281-2292 ◽  
Author(s):  
Constantinos Petrovas ◽  
Joseph P. Casazza ◽  
Jason M. Brenchley ◽  
David A. Price ◽  
Emma Gostick ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Antigen Specificity ◽  
Chronic Infections ◽  
Human Virus ◽  
Memory Cd8 T Cells ◽  
Persistent Virus

Here, we report on the expression of programmed death (PD)-1 on human virus-specific CD8+ T cells and the effect of manipulating signaling through PD-1 on the survival, proliferation, and cytokine function of these cells. PD-1 expression was found to be low on naive CD8+ T cells and increased on memory CD8+ T cells according to antigen specificity. Memory CD8+ T cells specific for poorly controlled chronic persistent virus (HIV) more frequently expressed PD-1 than memory CD8+ T cells specific for well-controlled persistent virus (cytomegalovirus) or acute (vaccinia) viruses. PD-1 expression was independent of maturational markers on memory CD8+ T cells and was not directly associated with an inability to produce cytokines. Importantly, the level of PD-1 surface expression was the primary determinant of apoptosis sensitivity of virus-specific CD8+ T cells. Manipulation of PD-1 led to changes in the ability of the cells to survive and expand, which, over several days, affected the number of cells expressing cytokines. Therefore, PD-1 is a major regulator of apoptosis that can impact the frequency of antiviral T cells in chronic infections such as HIV, and could be manipulated to improve HIV-specific CD8+ T cell numbers, but possibly not all functions in vivo.

scholarly journals Regulation of Memory CD8 T-Cell Differentiation by Cyclin-Dependent Kinase Inhibitor p27Kip1

2010 ◽  
Vol 30 (21) ◽  
pp. 5145-5159 ◽  
Author(s):  
Anju Singh ◽  
Anna Jatzek ◽  
Erin Hemmila Plisch ◽  
Rajini Srinivasan ◽  
John Svaren ◽  
...  
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Kinase Inhibitor ◽  
Cd8 T Cell ◽  
T Cell Memory ◽  
Cell Memory ◽  
Memory Cd8 T Cells ◽  
Cyclin Dependent Kinase Inhibitor

ABSTRACT Induction of potent T-cell memory is the goal of vaccinations, but the molecular mechanisms that regulate the formation of memory CD8 T cells are not well understood. Despite the recognition that controls of cellular proliferation and apoptosis govern the number of memory T cells, the cell cycle regulatory mechanisms that control these key cellular processes in CD8 T cells during an immune response are poorly defined. Here, we have identified the cyclin-dependent kinase inhibitor p27Kip1 as a critical regulator of the CD8 T-cell homeostasis at all phases of the T-cell response to an acute viral infection in mice. By acting as a timer for cell cycle exit, p27Kip1 curtailed the programmed expansion of interleukin-2-producing memory precursors and markedly limited the magnitude and quality of CD8 T-cell memory. In the absence of p27Kip1, CD8 T cells showed superior recall responses shortly after vaccination with recombinant Listeria monocytogenes. Additionally, we show that p27Kip1 constrains proliferative renewal of memory CD8 T cells, especially of the effector memory subset. These findings provide critical insights into the cell cycle regulation of CD8 T-cell homeostasis and suggest that modulation of p27Kip1 could bolster vaccine-induced T-cell memory and protective immunity.

scholarly journals IL-4 sensitivity shapes the peripheral CD8+ T cell pool and response to infection

2016 ◽  
Vol 213 (7) ◽  
pp. 1319-1329 ◽  
Author(s):  
Kristin R. Renkema ◽  
June-Yong Lee ◽  
You Jeong Lee ◽  
Sara E. Hamilton ◽  
Kristin A. Hogquist ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Antigen Specificity ◽  
Th1 Cell ◽  
Memory Cd8 T Cells ◽  
Expression Levels ◽  
Cell Pool

Previous studies have revealed that a population of innate memory CD8+ T cells is generated in response to IL-4, first appearing in the thymus and bearing high expression levels of Eomesodermin (Eomes) but not T-bet. However, the antigen specificity and functional properties of these cells is poorly defined. In this study, we show that IL-4 regulates not only the frequency and function of innate memory CD8+ T cells, but also regulates Eomes expression levels and functional reactivity of naive CD8+ T cells. Lack of IL-4 responsiveness attenuates the capacity of CD8+ T cells to mount a robust response to lymphocytic choriomeningitis virus infection, with both quantitative and qualitative effects on effector and memory antigen-specific CD8+ T cells. Unexpectedly, we found that, although numerically rare, memory phenotype CD8+ T cells in IL-4Rα–deficient mice exhibited enhanced reactivity after in vitro and in vivo stimulation. Importantly, our data revealed that these effects of IL-4 exposure occur before, not during, infection. Together, these data show that IL-4 influences the entire peripheral CD8+ T cell pool, influencing expression of T-box transcription factors, functional reactivity, and the capacity to respond to infection. These findings indicate that IL-4, a canonical Th2 cell cytokine, can sometimes promote rather than impair Th1 cell–type immune responses.

scholarly journals Teriflunomide Treatment of Multiple Sclerosis Selectively Modulates CD8 Memory T Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Gaëlle Tilly ◽  
Marion Cadoux ◽  
Alexandra Garcia ◽  
Jérémy Morille ◽  
Sandrine Wiertlewski ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
De Novo ◽  
Negative Impact ◽  
Adaptive Immune System ◽  
Underlying Mechanism ◽  
High Dimensional ◽  
Memory Cd8 T Cells ◽  
The Impact

Background and ObjectivesInhibition of de novo pyrimidine synthesis in proliferating T and B lymphocytes by teriflunomide, a pharmacological inhibitor of dihydroorotate dehydrogenase (DHODH), has been shown to be an effective therapy to treat patients with MS in placebo-controlled phase 3 trials. Nevertheless, the underlying mechanism contributing to the efficacy of DHODH inhibition has been only partially elucidated. Here, we aimed to determine the impact of teriflunomide on the immune compartment in a longitudinal high-dimensional follow-up of patients with relapse-remitting MS (RRMS) treated with teriflunomide.MethodsHigh-dimensional spectral flow cytometry was used to analyze the phenotype and the function of innate and adaptive immune system of patients with RRMS before and 12 months after teriflunomide treatment. In addition, we assessed the impact of teriflunomide on the migration of memory CD8 T cells in patients with RRMS, and we defined patient immune metabolic profiles.ResultsWe found that 12 months of treatment with teriflunomide in patients with RRMS does not affect the B cell or CD4 T cell compartments, including regulatory TREG follicular helper TFH cell and helper TH cell subsets. In contrast, we observed a specific impact of teriflunomide on the CD8 T cell compartment, which was characterized by decreased homeostatic proliferation and reduced production of TNFα and IFNγ. Furthermore, we showed that DHODH inhibition also had a negative impact on the migratory velocity of memory CD8 T cells in patients with RRMS. Finally, we showed that the susceptibility of memory CD8 T cells to DHODH inhibition was not related to impaired metabolism.DiscussionOverall, these findings demonstrate that the clinical efficacy of teriflunomide results partially in the specific susceptibility of memory CD8 T cells to DHODH inhibition in patients with RRMS and strengthens active roles for these T cells in the pathophysiological process of MS.

scholarly journals Ecto-5′-Nucleotidase (CD73) Regulates the Survival of CD8+ T Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Mariana V. Rosemblatt ◽  
Brian Parra-Tello ◽  
Pedro Briceño ◽  
Elizabeth Rivas-Yáñez ◽  
Suat Tucer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Interleukin 2 ◽  
Cd8 T Cell ◽  
Antigenic Stimulation ◽  
T Cell Subsets ◽  
Limited Information ◽  
Α Chain ◽  
The Impact

Ecto-5′-nucleotidase (CD73) is an enzyme present on the surface of tumor cells whose primary described function is the production of extracellular adenosine. Due to the immunosuppressive properties of adenosine, CD73 is being investigated as a target for new antitumor therapies. We and others have described that CD73 is present at the surface of different CD8+ T cell subsets. Nonetheless, there is limited information as to whether CD73 affects CD8+ T cell proliferation and survival. In this study, we assessed the impact of CD73 deficiency on CD8+ T cells by analyzing their proliferation and survival in antigenic and homeostatic conditions. Results obtained from adoptive transfer experiments demonstrate a paradoxical role of CD73. On one side, it favors the expression of interleukin-7 receptor α chain on CD8+ T cells and their homeostatic survival; on the other side, it reduces the survival of activated CD8+ T cells under antigenic stimulation. Also, upon in vitro antigenic stimulation, CD73 decreases the expression of interleukin-2 receptor α chain and the anti-apoptotic molecule Bcl-2, findings that may explain the reduced CD8+ T cell survival observed in this condition. These results indicate that CD73 has a dual effect on CD8+ T cells depending on whether they are subject to an antigenic or homeostatic stimulus, and thus, special attention should be given to these aspects when considering CD73 blockade in the design of novel antitumor therapies.

scholarly journals Tumor Necrosis Factor Receptor-1 (p55) Deficiency Attenuates Tumor Growth and Intratumoral Angiogenesis and Stimulates CD8+ T Cell Function in Melanoma

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2469
Author(s):  
Yamila I. Rodriguez ◽  
Ludmila E. Campos ◽  
Melina G. Castro ◽  
Nadia Bannoud ◽  
Ada G. Blidner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Necrosis Factor ◽  
Tumor Cell ◽  
Cd8 T Cells ◽  
Tumor Necrosis ◽  
Cd8 T Cell ◽  
Tnf Α ◽  
The Impact ◽  
Necrosis Factor

The role of tumor necrosis factor-α (TNF-α) in shaping the tumor microenvironment is ambiguous. Consistent with its uncertain role in melanoma, TNF-α plays a dual role, either acting as a cytotoxic cytokine or favoring a tumorigenic inflammatory microenvironment. TNF-α signals via two cognate receptors, namely TNFR1 (p55) and TNFR2 (p75), which mediate divergent biological activities. Here, we analyzed the impact of TNFR1 deficiency in tumor progression in the B16.F1 melanoma model. Tumors developed in mice lacking TNFR1 (TNFR1 knock-out; KO) were smaller and displayed lower proliferation compared to their wild type (WT) counterpart. Moreover, TNFR1 KO mice showed reduced tumor angiogenesis. Although no evidence of spontaneous metastases was observed, conditioned media obtained from TNFR1 KO tumors increased tumor cell migration. Whereas the analysis of tumor-associated immune cell infiltrates showed similar frequency of total and M2-polarized tumor-associated macrophages (TAMs), the percentage of CD8+ T cells was augmented in TNFR1 KO tumors. Indeed, functional ex vivo assays demonstrated that CD8+ T cells obtained from TNFR1KO mice displayed an increased cytotoxic function. Thus, lack of TNFR1 attenuates melanoma growth by modulating tumor cell proliferation, migration, angiogenesis and CD8+ T cell accumulation and activation, suggesting that interruption of TNF-TNFR1 signaling may contribute to control tumor burden.

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