scholarly journals Phenotypical and functional alteration of unconventional T cells in severe COVID-19 patients

2020 ◽  
Vol 217 (12) ◽  
Author(s):  
Youenn Jouan ◽  
Antoine Guillon ◽  
Loïc Gonzalez ◽  
Yonatan Perez ◽  
Chloé Boisseau ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Biology ◽  
Potential Contribution ◽  
Inkt Cells ◽  
Mait Cells ◽  
Phenotypic Alteration ◽  
T Cell Biology ◽  
Life Threatening ◽  
Regulatory Functions ◽  
Functional Alteration

COVID-19 includes lung infection ranging from mild pneumonia to life-threatening acute respiratory distress syndrome (ARDS). Dysregulated host immune response in the lung is a key feature in ARDS pathophysiology. However, cellular actors involved in COVID-19–driven ARDS are poorly understood. Here, in blood and airways of severe COVID-19 patients, we serially analyzed unconventional T cells, a heterogeneous class of T lymphocytes (MAIT, γδT, and iNKT cells) with potent antimicrobial and regulatory functions. Circulating unconventional T cells of COVID-19 patients presented with a profound and persistent phenotypic alteration. In the airways, highly activated unconventional T cells were detected, suggesting a potential contribution in the regulation of local inflammation. Finally, expression of the CD69 activation marker on blood iNKT and MAIT cells of COVID-19 patients on admission was predictive of clinical course and disease severity. Thus, COVID-19 patients present with an altered unconventional T cell biology, and further investigations will be required to precisely assess their functions during SARS–CoV-2–driven ARDS.

scholarly journals Plasticity within the αβ + CD4 + T-cell lineage: when, how and what for?

Open Biology ◽  
2013 ◽  
Vol 3 (1) ◽  
pp. 120157 ◽  
Author(s):  
Stephanie M. Coomes ◽  
Victoria S. Pelly ◽  
Mark S. Wilson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Biology ◽  
Cell Lineage ◽  
Cell Plasticity ◽  
New Paradigm ◽  
Follicular Helper ◽  
Single Function ◽  
T Cell Biology ◽  
Regulatory Functions

Following thymic output, αβ + CD4 + T cells become activated in the periphery when they encounter peptide–major histocompatibility complex. A combination of cytokine and co-stimulatory signals instructs the differentiation of T cells into various lineages and subsequent expansion and contraction during an appropriate and protective immune response. Our understanding of the events leading to T-cell lineage commitment has been dominated by a single fate model describing the commitment of T cells to one of several helper (T H ), follicular helper (T FH ) or regulatory (T REG ) phenotypes. Although a single lineage-committed and dedicated T cell may best execute a single function, the view of a single fate for T cells has recently been challenged. A relatively new paradigm in αβ + CD4 + T-cell biology indicates that T cells are much more flexible than previously appreciated, with the ability to change between helper phenotypes, between helper and follicular helper, or, most extremely, between helper and regulatory functions. In this review, we comprehensively summarize the recent literature identifying when T H or T REG cell plasticity occurs, provide potential mechanisms of plasticity and ask if T-cell plasticity is beneficial or detrimental to immunity.

scholarly journals Regulation and Functions of Protumoral Unconventional T Cells in Solid Tumors

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3578
Author(s):  
Emilie Barsac ◽  
Carolina de Amat Herbozo ◽  
Loïc Gonzalez ◽  
Thomas Baranek ◽  
Thierry Mallevaey ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Immunity ◽  
Cell Biology ◽  
Therapeutic Potential ◽  
Γδ T Cells ◽  
Feasibility Studies ◽  
T Cell Subsets ◽  
Mait Cells ◽  
Nonpeptide Antigens

The vast majority of studies on T cell biology in tumor immunity have focused on peptide-reactive conventional T cells that are restricted to polymorphic major histocompatibility complex molecules. However, emerging evidence indicated that unconventional T cells, including γδ T cells, natural killer T (NKT) cells and mucosal-associated invariant T (MAIT) cells are also involved in tumor immunity. Unconventional T cells span the innate–adaptive continuum and possess the unique ability to rapidly react to nonpeptide antigens via their conserved T cell receptors (TCRs) and/or to activating cytokines to orchestrate many aspects of the immune response. Since unconventional T cell lineages comprise discrete functional subsets, they can mediate both anti- and protumoral activities. Here, we review the current understanding of the functions and regulatory mechanisms of protumoral unconventional T cell subsets in the tumor environment. We also discuss the therapeutic potential of these deleterious subsets in solid cancers and why further feasibility studies are warranted.

scholarly journals T Cell Receptor Specificity Is Critical for the Development of Epidermal γδ T Cells

2001 ◽  
Vol 194 (10) ◽  
pp. 1473-1483 ◽  
Author(s):  
Isabel Ferrero ◽  
Anne Wilson ◽  
Friedrich Beermann ◽  
Werner Held ◽  
H. Robson MacDonald
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Biology ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Wild Type ◽  
Normal Numbers ◽  
T Cell Biology

A particular feature of γδ T cell biology is that cells expressing T cell receptor (TCR) using specific Vγ/Vδ segments are localized in distinct epithelial sites, e.g., in mouse epidermis nearly all γδ T cells express Vγ3/Vδ1. These cells, referred to as dendritic epidermal T cells (DETC) originate from fetal Vγ3+ thymocytes. The role of γδ TCR specificity in DETC's migration/localization to the skin has remained controversial. To address this issue we have generated transgenic (Tg) mice expressing a TCR δ chain (Vδ6.3-Dδ1-Dδ2-Jδ1-Cδ), which can pair with Vγ3 in fetal thymocytes but is not normally expressed by DETC. In wild-type (wt) Vδ6.3Tg mice DETC were present and virtually all of them express Vδ6.3. However, DETC were absent in TCR-δ−/− Vδ6.3Tg mice, despite the fact that Vδ6.3Tg γδ T cells were present in normal numbers in other lymphoid and nonlymphoid tissues. In wt Vδ6.3Tg mice, a high proportion of in-frame Vδ1 transcripts were found in DETC, suggesting that the expression of an endogenous TCR-δ (most probably Vδ1) was required for the development of Vδ6.3+ epidermal γδ T cells. Collectively our data demonstrate that TCR specificity is essential for the development of γδ T cells in the epidermis. Moreover, they show that the TCR-δ locus is not allelically excluded.

Interferon- Activates Multiple STAT Proteins and Upregulates Proliferation-Associated IL-2R, c-myc, and pim-1 Genes in Human T Cells

Blood ◽  
1999 ◽  
Vol 93 (6) ◽  
pp. 1980-1991 ◽  
Author(s):  
Sampsa Matikainen ◽  
Timo Sareneva ◽  
Tapani Ronni ◽  
Anne Lehtonen ◽  
Päivi J. Koskinen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Cell Biology ◽  
Interleukin 2 ◽  
T Cell Proliferation ◽  
Stat Proteins ◽  
Human T Cells ◽  
T Cell Biology ◽  
Cytokine Stimulation

Interferon- (IFN-) is a pleiotropic cytokine that has antiviral, antiproliferative, and immunoregulatory functions. There is increasing evidence that IFN- has an important role in T-cell biology. We have analyzed the expression ofIL-2R, c-myc, and pim-1 genes in anti-CD3–activated human T lymphocytes. The induction of these genes is associated with interleukin-2 (IL-2)–induced T-cell proliferation. Treatment of T lymphocytes with IFN-, IL-2, IL-12, and IL-15 upregulated IL-2R, c-myc, andpim-1 gene expression. IFN- also sensitized T cells to IL-2–induced proliferation, further suggesting that IFN- may be involved in the regulation of T-cell mitogenesis. When we analyzed the nature of STAT proteins capable of binding to IL-2R,pim-1, and IRF-1 GAS elements after cytokine stimulation, we observed IFN-–induced binding of STAT1, STAT3, and STAT4, but not STAT5 to all of these elements. Yet, IFN- was able to activate binding of STAT5 to the high-affinity IFP53 GAS site. IFN- enhanced tyrosine phosphorylation of STAT1, STAT3, STAT4, STAT5a, and STAT5b. IL-12 induced STAT4 and IL-2 and IL-15 induced STAT5 binding to the GAS elements. Taken together, our results suggest that IFN-, IL-2, IL-12, and IL-15 have overlapping activities on human T cells. These findings thus emphasize the importance of IFN- as a T-cell regulatory cytokine.

scholarly journals The New Old CD8+ T Cells in the Immune Paradox of Pregnancy

2021 ◽  
Vol 12 ◽  
Author(s):  
Lilja Hardardottir ◽  
Maria Victoria Bazzano ◽  
Laura Glau ◽  
Luca Gattinoni ◽  
Angela Köninger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Biology ◽  
Immune Cell ◽  
Cd8 T Cell ◽  
Therapeutic Interventions ◽  
Effector Memory ◽  
Pregnant Uterus ◽  
T Cell Biology

CD8+ T cells are the most frequent T cell population in the immune cell compartment at the feto-maternal interface. Due to their cytotoxic potential, the presence of CD8+ T cells in the immune privileged pregnant uterus has raised considerable interest. Here, we review our current understanding of CD8+ T cell biology in the uterus of pregnant women and discuss this knowledge in relation to a recently published immune cell Atlas of human decidua. We describe how the expansion of CD8+ T cells with an effector memory phenotype often presenting markers of exhaustion is critical for a successful pregnancy, and host defense towards pathogens. Moreover, we review new evidence on the presence of long-lasting immunological memory to former pregnancies and discuss its impact on prospective pregnancy outcomes. The formation of fetal-specific memory CD8+ T cell subests in the uterus, in particular of tissue resident, and stem cell memory cells requires further investigation, but promises interesting results to come. Advancing the knowledge of CD8+ T cell biology in the pregnant uterus will be pivotal for understanding not only tissue-specific immune tolerance but also the etiology of complications during pregnancy, thus enabling preventive or therapeutic interventions in the future.

scholarly journals Phospholipase Cγ1 is essential for T cell development, activation, and tolerance

2010 ◽  
Vol 207 (2) ◽  
pp. 309-318 ◽  
Author(s):  
Guoping Fu ◽  
Yuhong Chen ◽  
Mei Yu ◽  
Andy Podd ◽  
James Schuman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Biology ◽  
T Cell Development ◽  
Cell Receptor ◽  
Cell Development ◽  
Phospholipase Cγ1 ◽  
T Cell Biology ◽  
Single Positive ◽  
And Function

Phospholipase Cγ1 (PLCγ1) is an important signaling effector of T cell receptor (TCR). To investigate the role of PLCγ1 in T cell biology, we generated and examined mice with T cell–specific deletion of PLCγ1. We demonstrate that PLCγ1 deficiency affects positive and negative selection, significantly reduces single-positive thymocytes and peripheral T cells, and impairs TCR-induced proliferation and cytokine production, and the activation of ERK, JNK, AP-1, NFAT, and NF-κB. Importantly, PLCγ1 deficiency impairs the development and function of FoxP3+ regulatory T cells, causing inflammatory/autoimmune symptoms. Therefore, PLCγ1 is essential for T cell development, activation, and tolerance.

scholarly journals The Great War of Today: Modifications of CAR-T Cells to Effectively Combat Malignancies

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2030
Author(s):  
Andriy Zhylko ◽  
Magdalena Winiarska ◽  
Agnieszka Graczyk-Jarzynka
Keyword(s):  
T Cells ◽  
Cell Biology ◽  
Solid Tumours ◽  
Antigen Receptors ◽  
Therapeutic Outcomes ◽  
Solid Malignancies ◽  
T Cell Biology ◽  
Car T ◽  
Immunotherapy Of Cancer ◽  
The Times

Immunotherapy of cancer had its early beginnings in the times when the elements of the immune system were still poorly characterized. However, with the progress in molecular biology, it has become feasible to re-engineer T cells in order to eradicate tumour cells. The use of synthetic chimeric antigen receptors (CARs) helped to re-target and simultaneously unleash the cytotoxic potential of T cells. CAR-T therapy proved to be remarkably effective in cases of haematological malignancies, often refractory and relapsed. The success of this approach yielded two Food and Drug Administration (FDA) approvals for the first “living drug” modalities. However, CAR-T therapy is not without flaws. Apart from the side effects associated with the treatment, it became apparent that CAR introduction alters T cell biology and the possible therapeutic outcomes. Additionally, it was shown that CAR-T approaches in solid tumours do not recapitulate the success in the haemato-oncology. Therefore, in this review, we aim to discuss the recent concerns of CAR-T therapy for both haematological and solid tumours. We also summarise the general strategies that are implemented to enhance the efficacy and safety of the CAR-T regimens in blood and solid malignancies.

scholarly journals The Unknown Unknowns: Recovering Gamma-Delta T Cells for Control of Human Immunodeficiency Virus (HIV)

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1455
Author(s):  
Shivkumar Biradar ◽  
Michael T. Lotze ◽  
Robbie B. Mailliard
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cell Biology ◽  
Γδ T Cells ◽  
Γδ T Cell ◽  
T Cell Biology ◽  
Immunodeficiency Virus

Recent advances in γδ T cell biology have focused on the unique attributes of these cells and their role in regulating innate and adaptive immunity, promoting tissue homeostasis, and providing resistance to various disorders. Numerous bacterial and viral pathogens, including human immunodeficiency virus-1 (HIV), greatly alter the composition of γδ T cells in vivo. Despite the effectiveness of antiretroviral therapy (ART) in controlling HIV and restoring health in those affected, γδ T cells are dramatically impacted during HIV infection and fail to reconstitute to normal levels in HIV-infected individuals during ART for reasons that are not clearly understood. Importantly, their role in controlling HIV infection, and the implications of their failure to rebound during ART are also largely unknown and understudied. Here, we review important aspects of human γδ T cell biology, the effector and immunomodulatory properties of these cells, their prevalence and function in HIV, and their immunotherapeutic potential.

scholarly journals Statins as Modulators of Regulatory T-Cell Biology

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
David A. Forero-Peña ◽  
Fredy R. S. Gutierrez
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cell Biology ◽  
Experimental Studies ◽  
Potential Effect ◽  
T Cell Biology ◽  
Coa Reductase ◽  
Multiple Conditions

Statins are pharmacological inhibitors of the activity of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR), an enzyme responsible for the synthesis of cholesterol. Some recent experimental studies have shown that besides their effects on the primary and secondary prevention of cardiovascular diseases, statins may also have beneficial anti-inflammatory effects through diverse mechanisms. On the other hand, the induction and activity of regulatory T cells (Treg) are key processes in the prevention of pathology during chronic inflammatory and autoimmune diseases. Hence, strategies oriented towards the therapeutic expansion of Tregs are gaining special attention among biomedical researchers. The potential effects of statins on the biology of Treg are of particular importance because of their eventual application asin vivoinducers of Treg in the treatment of multiple conditions. In this paper we review the experimental evidence pointing out to a potential effect of statins on the role of regulatory T cells in different conditions and discuss its potential clinical significance.

scholarly journals Classical MHC expression by DP thymocytes impairs the selection of non-classical MHC restricted innate-like T cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hristo Georgiev ◽  
Changwei Peng ◽  
Matthew A. Huggins ◽  
Stephen C. Jameson ◽  
Kristin A. Hogquist
Keyword(s):  
T Cells ◽  
Epithelial Cells ◽  
Cell Types ◽  
Inkt Cells ◽  
Mhc I ◽  
Mait Cells ◽  
Mhc Molecules ◽  
Mhc Ii ◽  
Different Cell Types ◽  
Selection Of

AbstractConventional T cells are selected by peptide-MHC expressed by cortical epithelial cells in the thymus, and not by cortical thymocytes themselves that do not express MHC I or MHC II. Instead, cortical thymocytes express non-peptide presenting MHC molecules like CD1d and MR1, and promote the selection of PLZF+ iNKT and MAIT cells, respectively. Here, we report an inducible class-I transactivator mouse that enables the expression of peptide presenting MHC I molecules in different cell types. We show that MHC I expression in DP thymocytes leads to expansion of peptide specific PLZF+ innate-like (PIL) T cells. Akin to iNKT cells, PIL T cells differentiate into three functional effector subsets in the thymus, and are dependent on SAP signaling. We demonstrate that PIL and NKT cells compete for a narrow niche, suggesting that the absence of peptide-MHC on DP thymocytes facilitates selection of non-peptide specific lymphocytes.

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