Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P08758 (annexin V)
 9,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been proposed that direct and indirect mechanisms contribute to the unresolved issue of CD4(+) T-cell depletion that results from HIV-1 infection. We recently reported that plasma levels of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) are elevated in HIV-1-infected patients and that they correlate with viral load. The present study investigates the expression of TRAIL death receptor 5 (DR5) in the peripheral-blood mononuclear cells (PBMCs) of HIV-1-infected patients and its role in CD4(+) T-cell death. DR5 expression was elevated and associated with the apoptotic marker annexin V. Apoptosis was reduced in CD4(+) T cells when cultured with anti-DR5 antibody. CD4(+), but not CD8(+), T cells from uninfected donors expressed TRAIL, DR5, and activated caspase-3 when cultured with infectious or noninfectious HIV-1, resulting in preferential apoptosis of CD4(+) T cells. TRAIL, caspase-3 expression, and apoptosis were type 1 interferon (IFN) dependent. Induction of apoptosis and DR5 expression required glycoprotein 120 (gp120)-CD4 interaction. Finally, we analyzed DR5 expression by CD4(+) T cells in highly active antiretroviral therapy (HAART)-treated patients. The decreased viral loads and increased CD4 counts of HAART-responsive patients were associated with a decrease in DR5 mRNA expression by CD4(+) T lymphocytes. We propose a novel model in which a type 1 IFN-regulated TRAIL /DR5 mechanism induces apoptosis of HIV-1-exposed CD4(+) T cells.
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PMID:CD4+ T-cell death induced by infectious and noninfectious HIV-1: role of type 1 interferon-dependent, TRAIL/DR5-mediated apoptosis. 1604 22

Increased secretion of tumor necrosis factor-alpha (TNF-alpha), along with interleukin-1 (IL-1) and interleukin-6 (IL-6), is important in the pathogenesis of rheumatoid arthritis (RA). T regulatory CD4(+)CD25(+) cells play a role in maintaining self-tolerance by downregulating Th1-induced proinflammation. This function has been found to be altered in active RA, whereas anti-TNF-alpha therapy has been found to improve the suppressive abilities of these cells. Our objectives were to investigate whether T regulatory cells in patients with active RA display a higher sensitivity to spontaneous apoptosis than in normals, and to look into the potential of infliximab (anti-TNF-alpha therapy) to reduce the sensitivity of these cells to spontaneous apoptosis. Seventeen patients suffering from active RA, having failed multiple disease-modifying antirheumatic drug (DMARD) therapies, were treated with infliximab. Spontaneous apoptosis (as detected by annexin V binding) was determined in all patients and compared with a group of normal individuals at baseline and after three months on infliximab treatment. Peripheral blood mononuclear cells were incubated in 24-well plates at 1 x 10(6) cells/mL for 48 hours. Annexin V binding on CD4(+)CD25(+) was assessed using three-color assay by flow cytometry. Prior to infliximab initiation, spontaneous apoptosis of T regulatory cells from active RA patients was found to be increased in comparison with controls (26 +/- 4.2% vs. 19.8 +/- 4.8%, respectively; P = 0.01). Three months later (while still on infliximab) spontaneous apoptosis was comparable in the two groups (20.7 +/- 5.2% vs. 20.9 +/- 3.4%; P 5 0.8). The absolute number of CD4(+)CD25(+) cells/mL in the peripheral blood at baseline was reduced in 11 out of 17 active RA patients when compared with that of the control group (24 +/- 7 vs. 32 +/- 11, respectively; P = 0.02). Following anti-TNF-alpha therapy, CD4(+)CD25(+) cell counts of patients were equivalent to those of normals. The alteration and reversal in both spontaneous apoptosis and cell count of T regulatory cells was found to correlate with RA disease activity. CD4(+)CD25(+) T regulatory cells display increased proclivity to undergo spontaneous apoptosis in active RA. Alterations in CD4(+)CD25(+) cell apoptosis and cell count were found to correlate with RA disease activity. Reversal of these deviations from normal was documented in association with the beneficial outcome of infliximab therapy.
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PMID:Increased spontaneous apoptosis of CD4+CD25+ T cells in patients with active rheumatoid arthritis is reduced by infliximab. 1612 91

Innate immune responses that operate through Toll-like receptors (TLRs) are actively involved in the development of diseases predominantly mediated by adaptive immune responses. This is true also for allergic disease, as TLRs have been found to be involved in the development of allergic airway inflammation. We investigated whether stimulating TLR2 also abrogates murine allergic conjunctivitis by upregulating Th1 responses. We found that treating mice during the efferent phase with the TLR2 agonist Pam3CSK4 significantly suppressed eosinophil infiltration into the conjunctiva. However, Pam3CSK4 treatment inhibited both the Th1 and Th2 responses in the mice, and also suppressed eosinophil infiltration in IFN-gamma knockout mice. Flow cytometric analysis demonstrated that Pam3CSK4 treatment significantly elevated the numbers of annexin V-positive splenocytes, especially CD4 positive T cells. Thus, the stimulation of TLR2 during the efferent phase of murine allergic conjunctivitis suppresses eosinophil infiltration by inducing CD4 positive T-cell apoptosis rather than upregulating Th1 responses.
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PMID:TLR2 agonist ameliorates murine experimental allergic conjunctivitis by inducing CD4 positive T-cell apoptosis rather than by affecting the Th1/Th2 balance. 1633 48

Programmed cell death (apoptosis) is a key mechanism for regulating lymphocyte numbers. Murine lymph node lymphocytes cultured in vitro without added stimuli show significant levels of apoptosis over 24 h, detectable by staining with Annexin V. CD4 and CD8 T lymphocytes from transgenic (Tg) mice expressing single CD45RABC or CD45RO isoforms show increased apoptosis and the extent of apoptosis is inversely correlated with the level of CD45 expression. CD45 Tg cells exhibit phosphatidyl serine translocation and DNA oligonucleosome formation, and can be partially rescued from apoptosis by culture in caspase inhibitors or common gamma-chain-binding cytokines. We conclude that CD45 is an important regulator of spontaneous apoptosis in T lymphocytes and this mechanism may contribute to the disease associations reported for individuals expressing CD45 variant alleles.
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PMID:CD45 regulates apoptosis in peripheral T lymphocytes. 1662 65

This work compares effect of histondeacetylase inhibitor, valproic acid (VA), on proliferation, differentiation and apoptosis induction in two human leukemic cell lines: HL-60 (human promyleocytic leukemia, p53 negative) and MOLT-4 (human T-lymphocyte leukemia, p53 wild type). Incubation with VA caused decrease in percentage of cells in S phase of cell cycle. The decrease was more intensive in HL-60 cells, where the cells in S phase were absent 6 days after the beginning of incubation with VA (4 mmol/l). 3-day-long incubation of HL-60 cells with 4 mmol/l VA caused differentiation of these cells, marked by increase in CD11b and co-stimulatory/adhesion molecule CD86, and induction of a significant apoptosis. Annexin V positive cells lost the CD11b antigen. 3-day-long incubation of MOLT-4 cells with VA (1-2 mmol/l) inhibited proliferation and decreased percentage of cells in S phase of the cell cycle. 90% of MOLT-4 cells are CD7 positive. This CD7 positivity is not changed during apoptosis induction (detected as Annexin V positivity). On the other hand, CD4 marker expression decreases after incubation with 1-2 mmol/l VA, but during apoptosis induction by 4 mmol/l VA, most of the apoptotic Annexin V positive cells were also CD4 positive. Using a clonogenic survival assay EC(50) for 3-day-long incubation with VA was determined. For HL-60 cells, the established EC(50) was 1.84 mmol/l, for MOLT-4 cells it was 1.76 mmol/l. Ability of VA to induce differentiation in HL-60 cells thus does not affect final cell killing. However, the elimination of the cells was considerably affected by presence of hematopoietic growth factors. 14-day-long incubation of HL-60 cells with VA in conditioned medium (source of IL-3, SCF, G-CSF) caused increase in EC(50) to 4 mmol/l, while in MOLT-4 cells (cultivation without conditioned medium), the EC(50) decreased to 0.63 mmol/l.
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PMID:Effect of valproic acid and antiapoptotic cytokines on differentiation and apoptosis induction of human leukemia cells. 1671 76

Marijuana cannabinoids, such as delta-9-tetrahydrocannabinoid (THC), suppress type 1 T-helper 1 (Th1) immunity in a variety of models, including infection with the intracellular pathogen Legionella pneumophila (Lp). To examine the cellular mechanism of this effect, bone marrow-derived dendritic cells (DCs) were purified from BALB/c mice and studied following infection and drug treatment. DCs infected in vitro with Lp were able to protect mice when injected prior to a lethal Lp infection; however, the immunization potential of the Lp-loaded cells along with Th1 cytokine production was attenuated by THC treatment at the time of in vitro infection. In addition, THC-treated and Lp-loaded DCs were poorly stimulated in culture-primed splenic CD4(+) T cells to produce interferon-gamma; however, this stimulating deficiency was reversed by adding recombinant interleukin (IL)-12p40 protein to the cultures. Moreover, THC treatment inhibited the expression of DC maturation markers, such as major histocompatibility complex class II and costimulatory molecules CD86 and CD40 as determined by flow cytometry and suppressed the Notch ligand, Del-ta4, as determined by reverse transcription-polymerase chain reaction. However, THC treatment did not affect other DC functions, such as intracellular killing of Lp, determined by colony-forming unit counts of bacteria, and Lp-induced apoptosis, determined by annexin V staining. In conclusion, the data suggest that THC inhibits Th1 activation by targeting essential DC functions, such as IL-12p40 secretion, maturation, and expression of costimulatory and polarizing molecules.
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PMID:Cannabinoid treatment suppresses the T-helper cell-polarizing function of mouse dendritic cells stimulated with Legionella pneumophila infection. 1683 56

Submandibular lymph nodes (SLN) are crucial for immune surveillance of the anterior ocular chamber and upper respiratory tract; little is known about how training and exercise affect SLN lymphocytes. The intent of this study was to describe the impact of long term freewheel running followed by acute strenuous exercise on SLN lymphocytes in mice. Female C57BL/6 mice were assigned to running wheels or remained sedentary for 8 months, and further randomized to treadmill exercise and sacrifice immediately, treadmill exercise and sacrifice 24 h after exercise cessation, or no treadmill exposure. SLN lymphocytes were isolated and analyzed for CD3, CD4, CD8, and CD19 cell surface markers, phosphatidylserine externalization as a marker of apoptosis, and intracellular glutathione as a marker of oxidative stress. Compared with running wheel mice, older sedentary mice had a lower percent of T cells and higher percent of B cells (p < 0.05). Although intracellular glutathione did not differ between groups, running mice had a lower percent of Annexin V(+) SLN lymphocytes 24 h after treadmill exercise. Further research will be needed to determine if voluntary exercise translates into improved anterior ocular and upper respiratory tract health.
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PMID:Long-duration freewheel running and submandibular lymphocyte response to forced exercise in older mice. 1690 2

Mistletoe (Viscum album L.) extracts (ME) have been shown to exhibit a bell-shaped curve of immunological efficacy and mistletoe lectins (MLs) were found to play an important role in this phenomenon. The aim of present in vivo study was to investigate the acute- and long-term effect of a standardized ME (Iscador M special) on thymocyte subpopulations and peripheral T cells using a murine (Balb/c) model. In thymus CD4-CD8- double negative (DN), CD4+CD8+ double positive (DP), CD4+ or CD8+ single positive T cells were determined 24 h after a single injection or following a long-term treatment (twice a week for 4 weeks) with three different dilutions of ME which are corresponding to 4.5 ng/ kg, 22.5 ng/kg and 112.5 ng/kg doses of MLs. The apoptosis of the thymocytes was also tested by flow cytometry using Annexin V and propidium iodide. 24 h after a single injection of ME only the lowest dose caused in the blood samples an elevated CD4+/CD8+ ratio and in thymus an enhanced proliferation of DN thymocytes indicating a similar bell-shaped curve of immunological efficacy. After a treatment for four weeks these responses were less intensive indicating that none of the three doses are immunologically optimal. Surprisingly, both in the acute and in the long-term trial only the lower doses induced significant enhancements in the ratio of apoptotic thymocytes. In addition, ME inhibited the dexamethasone (DX)-induced reduction of DN cell count in thymus, as well as the DX-induced decrease of CD4+/CD8+ ratio and CD4+ cell level in peripheral blood. These in vivo results suggest that investigation of thymocytes in vivo can be helpful in the immunological dose-finding since standardized ME is able to modulate the proliferation and apoptosis of thymocytes with a bell-shaped curve of efficacy. In addition, ME may act lymphoprotectively during DX treatment.
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PMID:Investigation of the effect of mistletoe (Viscum album L.) extract Iscador on the proliferation and apoptosis of murine thymocytes. 1692 24

To test the role of hepatitis C virus (HCV) in CD4 cell depletion in human immunodeficiency virus (HIV)-coinfected patients, T cell apoptosis was measured by annexin V labeling in 31 HIV-infected and 30 HIV-HCV-coinfected patients who were not receiving antiretroviral therapy. Apoptosis in naive CD4(+) T cells and in naive and memory CD8(+) T cells was significantly higher in HIV-HCV-coinfected than in monoinfected patients.
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PMID:Coinfection with hepatitis C virus increases lymphocyte apoptosis in HIV-infected patients. 1702 44

Plasmacytoid dendritic cells (PDC) are the natural type I IFN-producing cells that produce large amounts of IFN-alpha in response to viral stimulation. During attempts to isolate PDC from human PBMC, we observed that cross-linking a variety of cell surface receptors, including blood DC Ag (BDCA)-2, BDCA-4, CD4, or CD123 with Abs and immunobeads on PDC leads to inhibition of IFN-alpha production in response to HSV. To understand the mechanisms involved, a number of parameters were investigated. Cross-linking did not inhibit endocytosis of soluble Ag by PDC. Flow cytometry for annexin V and activated caspase-3 indicated that PDC are not undergoing apoptosis after receptor cross-linking. Cross-linking of CD123, but not the other receptors, caused the up-regulation of costimulatory molecules CD80 and CD86, as well as the down-regulation of CD62L, indicating PDC maturation. Thus, anti-CD123 Ab may be acting similar to the natural ligand, IL-3. Anti-phosphotyrosine Ab, as well as Ab to the IFN regulatory factor, IRF-7, was used in intracellular flow cytometry to elucidate the signaling pathways involved. Tyrosine phosphorylation occurred after cross-linking BDCA-2 and BDCA-4, but not CD4. Cross-linking did not affect IRF-7 levels in PDC, however, cross-linking BDCA-2, BDCA-4, and CD4, but not CD123, inhibited the ability of IRF-7 to translocate to the nucleus. Taken together, these results suggest that cross-linking BDCA-2, BDCA-4, and CD4 on PDC regulates IFN-alpha production at the level of IRF-7, while the decrease in IFN-alpha production after CD123 cross-linking is due to stimulation of the IL-3R and induction of PDC maturation.
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PMID:Receptor cross-linking on human plasmacytoid dendritic cells leads to the regulation of IFN-alpha production. 1705 7


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