scholarly journals Failure of HIV-exposed CD4+ T cells to activate dendritic cells is reversed by restoration of CD40/CD154 interactions

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 1989-1995 ◽  
Author(s):  
Rui Zhang ◽  
Jeffrey D. Lifson ◽  
Claire Chougnet
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Interleukin 10 ◽  
Interleukin 12 ◽  
Cell Mediated Immunity ◽  
Hiv Exposed

Because interactions between activated CD4+ T cells and antigen-presenting cells (APCs) are crucial for optimal APC function, defective CD4+ T-cell activation may contribute to APC dysregulation in HIV infection. Here, we show that CD4+ T cells exposed during stimulation to noninfectious HIV having functional envelope glycoproteins failed to provide activation signals to autologous dendritic cells (DCs). Consequently, important DC functions, including production of immunoregulatory cytokines (interleukin-12 p40 and interleukin-10) and up-regulation of costimulatory molecules (CD86, CD40, CD83), as well as the capacity to stimulate naive allogeneic T cells, were all adversely affected. The blunted up-regulation of CD154 in CD4+ T cells that were activated in the presence of noninfectious viruses is likely to be the major underlying mechanism for these defects. Addition of recombinant trimeric CD154 could restore production of cytokines by DCs cocultured with HIV-exposed T cells. Moreover, the functional defects mediated by coculture with HIV-exposed T cells were similar to those following antibody blockade of CD40-CD154 interactions. HIV-mediated blunted CD154 expression may thus play an important role in the suppression of cell-mediated immunity seen in HIV infection.

scholarly journals Immunomodulatory Effects of Polysaccharide from Marine FungusPhoma herbarumYS4108 on T Cells and Dendritic Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Song Chen ◽  
Ran Ding ◽  
Yan Zhou ◽  
Xian Zhang ◽  
Rui Zhu ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Interleukin 12 ◽  
Related Factors ◽  
Knock Out ◽  
Specific Immunity

YCP, as a kind of natural polysaccharides from the mycelium of marine filamentous fungusPhoma herbarumYS4108, has great antitumor potentialviaenhancement of host immune response, but little is known about the molecular mechanisms. In the present study, we mainly focused on the effects and mechanisms of YCP on the specific immunity mediated by dendritic cells (DCs) and T cells. T cell /DC activation-related factors including interferon- (IFN-)γ, interleukin-12 (IL-12), and IL-4 were examined with ELISA. Receptor knock-out mice and fluorescence-activated cell sorting are used to analyze the YCP-binding receptor of T cells and DCs. RT-PCR is utilized to measure MAGE-A3 for analyzing the tumor-specific killing effect. In our study, we demonstrated YCP can provide the second signal for T cell activation, proliferation, and IFN-γproduction through binding to toll-like receptor- (TLR-) 2 and TLR-4. YCP could effectively promote IL-12 secretion and expression of markers (CD80, CD86, and MHC II)viaTLR-4 on DCs. Antigen-specific immunity against mouse melanoma cells was strengthened through the activation of T cells and the enhancement of capacity of DCs by YCP. The data supported that YCP can exhibit specific immunomodulatory capacity mediated by T cells and DCs.

scholarly journals Contact-dependent delivery of IL-2 by dendritic cells to CD4 T cells in the contraction phase promotes their long-term survival

2019 ◽  
Vol 11 (2) ◽  
pp. 108-123
Author(s):  
Dan Tong ◽  
Li Zhang ◽  
Fei Ning ◽  
Ying Xu ◽  
Xiaoyu Hu ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Immune Memory ◽  
Term Survival

Abstract Common γ chain cytokines are important for immune memory formation. Among them, the role of IL-2 remains to be fully explored. It has been suggested that this cytokine is critically needed in the late phase of primary CD4 T cell activation. Lack of IL-2 at this stage sets for a diminished recall response in subsequent challenges. However, as IL-2 peak production is over at this point, the source and the exact mechanism that promotes its production remain elusive. We report here that resting, previously antigen-stimulated CD4 T cells maintain a minimalist response to dendritic cells after their peak activation in vitro. This subtle activation event may be induced by DCs without overt presence of antigen and appears to be stronger if IL-2 comes from the same dendritic cells. This encounter reactivates a miniature IL-2 production and leads a gene expression profile change in these previously activated CD4 T cells. The CD4 T cells so experienced show enhanced reactivation intensity upon secondary challenges later on. Although mostly relying on in vitro evidence, our work may implicate a subtle programing for CD4 T cell survival after primary activation in vivo.

Mechanism of Interleukin-10 Inhibition of T-Helper Cell Activation by Superantigen at the Level of the Cell Cycle

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 208-216 ◽  
Author(s):  
George Q. Perrin ◽  
Howard M. Johnson ◽  
Prem S. Subramaniam
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Interleukin 10 ◽  
Inhibitory Protein ◽  
Cell Functions

Abstract We have analyzed the effects of interleukin-10 (IL-10) on the entry of quiescent CD4+ T cells into the cell cycle upon stimulation with the superantigen staphylococcal enterotoxin B (SEB). IL-10 arrested cells at G0/G1. IL-10 treatment prevented the downregulation of p27Kip1, an inhibitory protein that controls progression out of the G0 phase of the cell cycle. IL-10 also prevented the upregulation of the G1 cyclins D2 and D3, proteins necessary for entry and progression through the G1 phase of the cell cycle. Associated with the inhibition of the cell cycle, IL-10 suppressed SEB induction of interleukin-2 (IL-2). Addition of exogenous IL-2 to IL-10–treated cells significantly reversed the antiproliferative effects of IL-10. Moreover, IL-10 effects on the early G1proteins p27Kip1 and cyclin D2 were similarly reversed by exogenous IL-2. Although this reversal by IL-2 was pronounced, it was not complete, suggesting that IL-10 may have some effects not directly related to the suppression of IL-2 production. Cell separation experiments suggest that IL-10 can effect purified CD4+ T cells directly, providing functional evidence for the presence of IL-10 receptors on CD4+ T cells. IL-10 also inhibited expression of IL-2 transcriptional regulators c-fos and c-jun, which also inhibit other cell functions. Our studies show that the mechanism of IL-10 regulation of quiescent CD4+ T-cell activation is mainly by blocking induction of IL-2 that is critical to downregulation of p27Kip1 and upregulation of D cyclins in T-cell activation and entry into the cell cycle.

Mechanism of Interleukin-10 Inhibition of T-Helper Cell Activation by Superantigen at the Level of the Cell Cycle

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 208-216
Author(s):  
George Q. Perrin ◽  
Howard M. Johnson ◽  
Prem S. Subramaniam
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Interleukin 10 ◽  
Inhibitory Protein ◽  
Cell Functions

We have analyzed the effects of interleukin-10 (IL-10) on the entry of quiescent CD4+ T cells into the cell cycle upon stimulation with the superantigen staphylococcal enterotoxin B (SEB). IL-10 arrested cells at G0/G1. IL-10 treatment prevented the downregulation of p27Kip1, an inhibitory protein that controls progression out of the G0 phase of the cell cycle. IL-10 also prevented the upregulation of the G1 cyclins D2 and D3, proteins necessary for entry and progression through the G1 phase of the cell cycle. Associated with the inhibition of the cell cycle, IL-10 suppressed SEB induction of interleukin-2 (IL-2). Addition of exogenous IL-2 to IL-10–treated cells significantly reversed the antiproliferative effects of IL-10. Moreover, IL-10 effects on the early G1proteins p27Kip1 and cyclin D2 were similarly reversed by exogenous IL-2. Although this reversal by IL-2 was pronounced, it was not complete, suggesting that IL-10 may have some effects not directly related to the suppression of IL-2 production. Cell separation experiments suggest that IL-10 can effect purified CD4+ T cells directly, providing functional evidence for the presence of IL-10 receptors on CD4+ T cells. IL-10 also inhibited expression of IL-2 transcriptional regulators c-fos and c-jun, which also inhibit other cell functions. Our studies show that the mechanism of IL-10 regulation of quiescent CD4+ T-cell activation is mainly by blocking induction of IL-2 that is critical to downregulation of p27Kip1 and upregulation of D cyclins in T-cell activation and entry into the cell cycle.

Endocytosis, intracellular sorting, and processing of exosomes by dendritic cells

Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3257-3266 ◽  
Author(s):  
Adrian E. Morelli ◽  
Adriana T. Larregina ◽  
William J. Shufesky ◽  
Mara L. G. Sullivan ◽  
Donna Beer Stolz ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Milk Fat ◽  
Cell Activation ◽  
Peripheral Tolerance ◽  
Indirect Pathway ◽  
Alternative Source ◽  
Mhc I

Abstract Exosomes are nanovesicles released by leukocytes and epithelial cells. Although their function remains enigmatic, exosomes are a source of antigen and transfer functional major histocompatibility complex (MHC)–I/peptide complexes to dendritic cells (DCs) for CD8+ T-cell activation. Here we demonstrate that exosomes also are internalized and processed by immature DCs for presentation to CD4+ T cells. Endocytosed exosomes are sorted into the endocytic compartment of DCs for processing, followed by loading of exosome-derived peptides in MHC-II molecules for presentation to CD4+ T cells. Targeting of exosomes to DCs is mediated via milk fat globule (MFG)–E8/lactadherin, CD11a, CD54, phosphatidylserine, and the tetraspanins CD9 and CD81 on the exosome and αv/β3 integrin, and CD11a and CD54 on the DCs. Circulating exosomes are internalized by DCs and specialized phagocytes of the spleen and by hepatic Kupffer cells. Internalization of blood-borne allogeneic exosomes by splenic DCs does not affect DC maturation and is followed by loading of the exosome-derived allopeptide IEα52-68 in IAb by host CD8α+ DCs for presentation to CD4+ T cells. These data imply that exosomes present in circulation or extracellular fluids constitute an alternative source of self- or allopeptides for DCs during maintenance of peripheral tolerance or initiation of the indirect pathway of allorecognition in transplantation.

scholarly journals Irreversible depletion of intestinal CD4+ T-cells is associated with T-cell activation during chronic HIV infection

JCI Insight ◽  
2021 ◽  
Author(s):  
Osaretin E. Asowata ◽  
Alveera Singh ◽  
Abigail Ngoepe ◽  
Nicholas Herbert ◽  
Rabiah Fardoos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Chronic Hiv Infection

scholarly journals Synergistic Activation of Bovine CD4+ T Cells by Neutrophils and IL-12

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 694
Author(s):  
Zhengguo Xiao ◽  
Anmol Kandel ◽  
Lei Li
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Interleukin 12 ◽  
Cd25 Expression ◽  
Synergistic Activation ◽  
Bovine Neutrophils

CD4+ T cell activation requires inflammatory cytokines to provide a third signal (3SI), such as interleukin-12 (IL-12). We recently reported that bovine neutrophils can enhance the activation of bovine CD4+ T cells. To explore the interactions between neutrophils and third signal cytokines in bovine CD4+ T cell activation, naïve CD4+ T cells were isolated from cattle lymph nodes and stimulated for 3.5 days with anti-bovine CD3 (first signal; 1SI), anti-bovine CD28 (second signal; 2SI), and recombinant human IL-12 (3SI) in the presence or absence of neutrophils harvested from the same animals. Indeed, the strongest activation was achieved in the presence of all three signals, as demonstrated by CD25 upregulation, IFNγ production in CD4+ T cells, and secretion of IFNγ and IL-2 in cell supernatants. More importantly, 1SI plus neutrophils led to enhanced CD25 expression that was further increased by IL-12, suggesting synergistic action by IL-12 and neutrophils. Consistently, neutrophils significantly increased IFNγ production in 1SI plus IL-12-stimulated CD4+ T cells. Our data suggest the synergy of neutrophils and IL-12 as a novel regulator on bovine CD4+ T cell activation in addition to three signals. This knowledge could assist the development of immune interventions for the control of infectious diseases in cattle.

scholarly journals Interleukin 12 and Interleukin 4 Control T Cell Adhesion to Endothelial Selectins through Opposite Effects on α1,3-fucosyltransferase VII Gene Expression

1998 ◽  
Vol 188 (12) ◽  
pp. 2225-2231 ◽  
Author(s):  
Amy J. Wagers ◽  
Christopher M. Waters ◽  
Lloyd M. Stoolman ◽  
Geoffrey S. Kansas
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Single Gene ◽  
Interleukin 4 ◽  
Th2 Cells ◽  
Interleukin 12 ◽  
Th 1

The α1,3-fucosyltransferase, FucT-VII, is crucial for the formation of ligands for all three selectins, and its expression regulates the synthesis of these ligands. Short-term polarized T helper (Th)1, but not Th2 or naive CD4+ T cells, can home to sites of inflammation, but the molecular basis for this difference has remained unclear. Here we show that naive CD4+ T cells do not express FucT-VII and fail to bind vascular selectins. We also show that when CD4+ T cells are activated in the presence of the Th1 polarizing cytokine interleukin (IL)-12, levels of FucT-VII mRNA and binding to E- and P-selectin are significantly augmented. In contrast, activation of CD4+ T cells in the presence of IL-4, a Th2 polarizing cytokine, inhibited FucT-VII expression and binding to vascular selectins. T cell activation upregulated expression of the Core2 transferase, C2GnT, equivalently regardless of the presence or absence of polarizing cytokines. These data indicate that the selective ability of Th1 cells, as opposed to Th2 cells or naive CD4+ T cells, to recognize vascular selectins and home to sites of inflammation is controlled principally by the expression of a single gene, FucT-VII.

scholarly journals Functional proteomic atlas of HIV infection in primary human CD4+ T cells

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Adi Naamati ◽  
James C Williamson ◽  
Edward JD Greenwood ◽  
Sara Marelli ◽  
Paul J Lehner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Biology ◽  
Cell Activation ◽  
Magnetic Beads ◽  
Host Cells ◽  
Dynamic Background

Viruses manipulate host cells to enhance their replication, and the identification of cellular factors targeted by viruses has led to key insights into both viral pathogenesis and cell biology. In this study, we develop an HIV reporter virus (HIV-AFMACS) displaying a streptavidin-binding affinity tag at the surface of infected cells, allowing facile one-step selection with streptavidin-conjugated magnetic beads. We use this system to obtain pure populations of HIV-infected primary human CD4+ T cells for detailed proteomic analysis, and quantitate approximately 9000 proteins across multiple donors on a dynamic background of T cell activation. Amongst 650 HIV-dependent changes (q < 0.05), we describe novel Vif-dependent targets FMR1 and DPH7, and 192 proteins not identified and/or regulated in T cell lines, such as ARID5A and PTPN22. We therefore provide a high-coverage functional proteomic atlas of HIV infection, and a mechanistic account of host factors subverted by the virus in its natural target cell.

scholarly journals Functional proteomic atlas of HIV-infection in primary human CD4+ T cells

2018 ◽  
Author(s):  
Adi Naamati ◽  
James C Williamson ◽  
Edward JD Greenwood ◽  
Sara Marelli ◽  
Paul J Lehner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Magnetic Beads ◽  
Host Cells ◽  
Global Changes ◽  
High Coverage

Viruses manipulate host cells to enhance their replication, and the identification of host factors targeted by viruses has led to key insights in both viral pathogenesis and cellular physiology. We previously described global changes in cellular protein levels during human immunodeficiency virus (HIV) infection using transformed CEM-T4 T cells as a model. In this study, we develop an HIV reporter virus displaying a streptavidin-binding affinity tag at the surface of infected cells, allowing facile one-step selection with streptavidin-conjugated magnetic beads. We use this system to obtain pure populations of HIV-infected primary human CD4+ T cells for detailed proteomic analysis, including quantitation of >9,000 proteins across 4 different donors, and temporal profiling during T cell activation. Remarkably, amongst 650 cellular proteins significantly perturbed during HIV infection of primary T cells (q<0.05), almost 50% are regulated directly or indirectly by the viral accessory proteins Vpr, Vif, Nef and Vpu. The remainder have not been previously characterised, but include novel Vif-dependent targets FMR1 and DPH7, and 192 targets not identified and/or regulated in T cell lines, such as AIRD5A and PTPN22. We therefore provide a high-coverage functional proteomic atlas of HIV infection, and a mechanistic account of HIV-dependent changes in its natural target cell.

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