scholarly journals Expansion and function of Foxp3-expressing T regulatory cells during tuberculosis

2007 ◽  
Vol 204 (9) ◽  
pp. 2159-2169 ◽  
Author(s):  
James P. Scott-Browne ◽  
Shahin Shafiani ◽  
Glady's Tucker-Heard ◽  
Kumiko Ishida-Tsubota ◽  
Jason D. Fontenot ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
T Regulatory Cells ◽  
Persistent Infections ◽  
Colony Forming Units ◽  
And Function ◽  
Aerosol Infection ◽  
Lymphoid Aggregates

Mycobacterium tuberculosis (Mtb) frequently establishes persistent infections that may be facilitated by mechanisms that dampen immunity. T regulatory (T reg) cells, a subset of CD4+ T cells that are essential for preventing autoimmunity, can also suppress antimicrobial immune responses. We use Foxp3-GFP mice to track the activity of T reg cells after aerosol infection with Mtb. We report that during tuberculosis, T reg cells proliferate in the pulmonary lymph nodes (pLNs), change their cell surface phenotype, and accumulate in the pLNs and lung at a rate parallel to the accumulation of effector T cells. In the Mtb-infected lung, T reg cells accumulate in high numbers in all sites where CD4+ T cells are found, including perivascular/peribronchiolar regions and within lymphoid aggregates of granulomas. To determine the role of T reg cells in the immune response to tuberculosis, we generated mixed bone marrow chimeric mice in which all cells capable of expressing Foxp3 expressed Thy1.1. When T reg cells were depleted by administration of anti-Thy1.1 before aerosol infection with Mtb, we observed ∼1 log less of colony-forming units of Mtb in the lungs. Thus, after aerosol infection, T reg cells proliferate and accumulate at sites of infection, and have the capacity to suppress immune responses that contribute to the control of Mtb.

scholarly journals T-bet represses collagen-induced arthritis by suppressing Th17 lineage commitment through inhibition of RORγt expression and function

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masaru Shimizu ◽  
Yuya Kondo ◽  
Reona Tanimura ◽  
Kotona Furuyama ◽  
Masahiro Yokosawa ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
T Helper 1 ◽  
Collagen Induced Arthritis ◽  
Over Expression ◽  
Th17 Differentiation ◽  
And Function ◽  
Arthritic Joints

AbstractT-bet is a key transcription factor for the T helper 1 lineage and its expression level is negatively correlated to inflammation in patients with rheumatoid arthritis (RA). Our previous study using T-bet transgenic mice revealed over-expression of T-bet completely suppressed collagen-induced arthritis (CIA), a murine model of RA, indicating a potential suppressive role of T-bet in the pathogenesis of autoimmune arthritis. Here, we show T-bet-deficiency exacerbated CIA. T-bet in CD4 + T cells, but not in CD11c + dendritic cells, was critical for regulating the production of IL-17A, IL-17F, IL-22, and TNFα from CD4 + T cells. T-bet-deficient CD4 + T cells showed higher RORγt expression and increased IL-17A production in RORγt-positive cells after CII immunization. In addition, T-bet-deficient naïve CD4 + T cells showed accelerated Th17 differentiation in vitro. CIA induced in CD4-Cre T-betfl/fl (cKO) mice was more severe and T-bet-deficient CD4 + T cells in the arthritic joints of cKO mice showed higher RORγt expression and increased IL-17A production. Transcriptome analysis of T-bet-deficient CD4 + T cells revealed that expression levels of Th17-related genes were selectively increased. Our results indicate that T-bet in CD4 + T cells repressed RORγt expression and function resulting in suppression of arthritogenic Th17 cells and CIA.

scholarly journals Role of Exosomes in the Regulation of T-cell Mediated Immune Responses and in Autoimmune Disease

Cells ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 154 ◽  
Author(s):  
Alberto Anel ◽  
Ana Gallego-Lleyda ◽  
Diego de Miguel ◽  
Javier Naval ◽  
Luis Martínez-Lostao
Keyword(s):  
T Cells ◽  
T Cell ◽  
Autoimmune Disease ◽  
Immune Responses ◽  
T Regulatory Cells ◽  
Inflammatory Diseases ◽  
Activated T Cells ◽  
Regulatory Processes ◽  
Activation Induced Cell Death

: T-cell mediated immune responses should be regulated to avoid the development of autoimmune or chronic inflammatory diseases. Several mechanisms have been described to regulate this process, namely death of overactivated T cells by cytokine deprivation, suppression by T regulatory cells (Treg), induction of expression of immune checkpoint molecules such as CTLA-4 and PD-1, or activation-induced cell death (AICD). In addition, activated T cells release membrane microvesicles called exosomes during these regulatory processes. In this review, we revise the role of exosome secretion in the different pathways of immune regulation described to date and its importance in the prevention or development of autoimmune disease. The expression of membrane-bound death ligands on the surface of exosomes during AICD or the more recently described transfer of miRNA or even DNA inside T-cell exosomes is a molecular mechanism that will be analyzed.

scholarly journals Aberrant Contraction of Antigen-Specific CD4 T Cells after Infection in the Absence of Gamma Interferon or Its Receptor

2006 ◽  
Vol 74 (11) ◽  
pp. 6252-6263 ◽  
Author(s):  
Jodie S. Haring ◽  
John T. Harty
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
Gamma Interferon ◽  
Model Systems ◽  
Important Regulator ◽  
Ifn Γ ◽  
And Function ◽  
Deficient Mice

ABSTRACT Several lines of evidence from different model systems suggest that gamma interferon (IFN-γ) is an important regulator of T-cell contraction after antigen (Ag)-driven expansion. To specifically investigate the role of IFN-γ in regulating the contraction of Ag-specific CD4 T cells, we infected IFN-γ−/− and IFN-γR1−/− mice with attenuated Listeria monocytogenes and monitored the numbers of Ag-specific CD4 T cells during the expansion, contraction, and memory phases of the immune response to infection. In the absence of IFN-γ or the ligand-binding portion of its receptor, Ag-specific CD4 T cells exhibited normal expansion in numbers, but in both strains of deficient mice there was very little decrease in the number of Ag-specific CD4 T cells even at time points later than day 90 after infection. This significant delay in contraction was not due to prolonged infection, since mice treated with antibiotics to conclusively eliminate infection exhibited the same defect in contraction. In addition to altering the number of Ag-specific CD4 T cells, the absence of IFN-γ signaling also changed the phenotype of cells generated after infection. IFN-γR1−/− Ag-specific CD4 T cells reacquired expression of CD127 more quickly than wild-type cells, and more IFN-γR1−/− CD4 T cells were capable of producing both IFN-γ and interleukin 2 following Ag stimulation. From these data we conclude that IFN-γ regulates the contraction, phenotype, and function of Ag-specific CD4 T cells generated after infection.

scholarly journals The Generation and Regulation of Tissue-Resident Tregs and Their Role in Autoimmune Diseases

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shuang Wang ◽  
Xueyang Zou ◽  
Yi Zhang ◽  
Xiaoya Wang ◽  
Wei Yang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
T Cells ◽  
Immune Responses ◽  
Autoimmune Diseases ◽  
Hot Spot ◽  
Exploratory Stage ◽  
And Function

Regulatory T cells (Tregs), as an important subset of T cells, play an important role in maintaining body homeostasis by regulating immune responses and preventing autoimmune diseases. In-depth research finds that Tregs have strong instability and plasticity, and according to their developmental origin, Tregs can be classified into thymic-derived Tregs (tTregs), endogenous-induced Tregs (pTregs), which are produced by antigen-stimulated T cells in the periphery in vivo, and induced Tregs (iTregs), which differentiate from naïve T cells in vitro. In recent years, studies have found that Tregs are divided into lymphatic and tissue-resident Tregs according to their location. Research on the generation and function of lymphoid Tregs has been more comprehensive and thorough, but the role of tissue Tregs is still in the exploratory stage, and it has become a research hot spot. In this review, we discuss the instability and plasticity of Tregs and the latest developments of tissue-resident Tregs in the field of biology, including adipose tissue, colon, skeletal muscle, and other Tregs that have been recently discovered as well as their production, regulation, and function in specific tissues and their role in the pathogenesis of autoimmune diseases.

scholarly journals Role of IL-2 secreted by PADRE-specific CD4+ T cells in enhancing E7-specific CD8+ T-cell immune responses

Gene Therapy ◽  
2008 ◽  
Vol 15 (9) ◽  
pp. 677-687 ◽  
Author(s):  
D Kim ◽  
A Monie ◽  
L He ◽  
Y-C Tsai ◽  
C-F Hung ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
Cd8 T Cell ◽  
T Cell Immune Responses

scholarly journals Differential Expression and Function of Phosphodiesterase 4 (PDE4) Subtypes in Human Primary CD4+ T Cells: Predominant Role of PDE4D

2007 ◽  
Vol 178 (8) ◽  
pp. 4820-4831 ◽  
Author(s):  
Daniel Peter ◽  
S. L. Catherine Jin ◽  
Marco Conti ◽  
Armin Hatzelmann ◽  
Christof Zitt
Keyword(s):  
T Cells ◽  
Differential Expression ◽  
Cd4 T Cells ◽  
Predominant Role ◽  
Phosphodiesterase 4 ◽  
And Function

scholarly journals Erratum: Role of IL-2 secreted by PADRE-specific CD4+ T cells in enhancing E7-specific CD8+ T-cell immune responses

Gene Therapy ◽  
2008 ◽  
Vol 15 (9) ◽  
pp. 702-702
Author(s):  
D Kim ◽  
A Monie ◽  
L He ◽  
Y-C Tsai ◽  
C-F Hung ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
Cd8 T Cell ◽  
T Cell Immune Responses

scholarly journals RAF kinases are stabilized and required for dendritic cell differentiation and function

2019 ◽  
Vol 27 (4) ◽  
pp. 1300-1315 ◽  
Author(s):  
Kristina Riegel ◽  
Janine Schlöder ◽  
Marco Sobczak ◽  
Helmut Jonuleit ◽  
Bernd Thiede ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Mapk Pathway ◽  
Adaptive Immune System ◽  
Dendritic Cell Differentiation ◽  
Protein Levels ◽  
Clinical Interest ◽  
Mapk Inhibitors ◽  
And Function

Abstract RAF kinases (ARAF, BRAF, and CRAF) are highly conserved enzymes that trigger the RAF-MEK1/2-ERK1/2 (MAPK) pathway upon activation of RAS. Despite enormous clinical interest, relatively little is known on the role of RAFs in mediating immune responses. Here, we investigated the role of RAF kinases and MEK1/2 in dendritic cells (DCs), the central regulators of T cell-mediated antitumor immune responses and the adaptive immune system. We demonstrate that RAF kinases are active and stabilized at their protein levels during DC differentiation. Inhibition of RAF kinases but not MEK1/2 impaired the activation of DCs in both mice and human. As expected, DCs treated with RAF inhibitors show defects in activating T cells. Further, RAF and MEK1/2 kinases are directly required for the activation and proliferation of CD4+ T cells. Our observations suggest that RAF and MEK1/2 have independent roles in regulating DC function that has important implications for administering RAF–MAPK inhibitors in the clinics.

scholarly journals IL-21 in Homeostasis of Resident Memory and Exhausted CD8 T Cells during Persistent Infection

2020 ◽  
Vol 21 (18) ◽  
pp. 6966
Author(s):  
Heather M. Ren ◽  
Aron E. Lukacher
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Persistent Infection ◽  
Cd4 T Cells ◽  
Cell Subset ◽  
Cd4 T Cell ◽  
Persistent Infections ◽  
Follicular Helper ◽  
And Function

CD4 T cells guide the development of CD8 T cells into memory by elaborating mitogenic and differentiation factors and by licensing professional antigen-presenting cells. CD4 T cells also act to stave off CD8 T cell dysfunction during repetitive antigen stimulation in persistent infection and cancer by mitigating generation of exhausted T cells (TEX). CD4 T cell help is also required for establishing and maintaining tissue-resident memory T cells (TRM), the nonrecirculating memory T cell subset parked in nonlymphoid tissues to provide frontline defense against reinvading pathogens. Interleukin (IL)-21 is the signature cytokine secreted by follicular helper CD4 T cells (TFH) to drive B cell expansion and differentiation in germinal centers to mount high-affinity, isotype class-switched antibodies. In several infection models, IL-21 has been identified as the CD4 T help needed for formation and survival of TRM and TEX. In this review, we will explore the different memory subsets of CD8 T cells in persistent infections, the metabolic profiles associated with each, and evidence documenting the importance of CD4 T cell-derived IL-21 in regulating CD8 TRM and TEX development, homeostasis, and function.

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