Synergistic stimulatory effects of tumour necrosis factor α and interferon γ on replication of human immunodeficiency virus type 1 and on apoptosis of HIV‐1‐infected host cells

1996 ◽  
Vol 26 (4) ◽  
pp. 286-292 ◽  
Author(s):  
X. HAN ◽  
K. BECKER ◽  
H. J. DEGEN ◽  
H. JABLONOWSKI ◽  
G. STROHMEYER
Keyword(s):  
Human Immunodeficiency Virus ◽  
Tumour Necrosis ◽  
Interferon Γ ◽  
Host Cells ◽  
Tumour Necrosis Factor Α ◽  
Immunodeficiency Virus ◽  
Factor Α ◽  
Hiv 1 ◽  
Necrosis Factor

scholarly journals Isolation and Characterization of the Fungal Metabolite 3-O-Methylviridicatin as an Inhibitor of Tumour Necrosis Factor α-Induced Human Immunodeficiency Virus Replication

1998 ◽  
Vol 9 (2) ◽  
pp. 149-155 ◽  
Author(s):  
A Heguy ◽  
P Cai ◽  
P Meyn ◽  
D Houck ◽  
S Russo ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Line ◽  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Luciferase Reporter ◽  
Tumour Necrosis Factor Α ◽  
Tnf Α ◽  
Immunodeficiency Virus ◽  
Factor Α ◽  
Necrosis Factor

The cytokine tumour necrosis factor α (TNF-α) has been shown to play a role in human immunodeficiency virus (HIV) replication by activating transcription of the provirus in both T cells and macrophages. Therefore, agents that block TNF-α-induced HIV expression could have therapeutic value in the treatment of AIDS. We have sought to identify antiviral agents that block TNF-α induction of HIV LTR-directed transcription, using a cell-based, virus-free assay system in automated high-throughput screening. HeLa cells were transfected with an HIV LTR–luciferase reporter plasmid and a stable line was isolated in which TNF-α increased luciferase production by two- to threefold. This cell line was used to screen approximately 15 000 fungal extracts. An inhibitory activity specific for TNF-α-induced HIV LTR transcription was observed in culture OS-F67406. The active component was isolated and identified as a known metabolite, 3-O-methylviridicatin, by NMR and mass spectrometry. No biological activity has been associated with this compound previously. This compound blocks TNF-α activation of the HIV LTR in the HeLa-based system, with an IC50 of 5 μM, and inhibited virus production in the OM-10.1 cell line, a model of chronic infection responsive to induction by TNF-α, with an IC50 of 2.5 μM.

scholarly journals Monitoring Early Fusion Dynamics of Human Immunodeficiency Virus Type 1 at Single-Molecule Resolution

2008 ◽  
Vol 82 (14) ◽  
pp. 7022-7033 ◽  
Author(s):  
Terrence M. Dobrowsky ◽  
Yan Zhou ◽  
Sean X. Sun ◽  
Robert F. Siliciano ◽  
Denis Wirtz
Keyword(s):  
Human Immunodeficiency Virus ◽  
Tensile Strength ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Single Molecule ◽  
Viral Envelope ◽  
Host Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The fusion of human immunodeficiency virus type 1 (HIV-1) to host cells is a dynamic process governed by the interaction between glycoproteins on the viral envelope and the major receptor, CD4, and coreceptor on the surface of the cell. How these receptors organize at the virion-cell interface to promote a fusion-competent site is not well understood. Using single-molecule force spectroscopy, we map the tensile strengths, lifetimes, and energy barriers of individual intermolecular bonds between CCR5-tropic HIV-1 gp120 and its receptors CD4 and CCR5 or CXCR4 as a function of the interaction time with the cell. According to the Bell model, at short times of contact between cell and virion, the gp120-CD4 bond is able to withstand forces up to 35 pN and has an initial lifetime of 0.27 s and an intermolecular length of interaction of 0.34 nm. The initial bond also has an energy barrier of 6.7 kB T (where kB is Boltzmann's constant and T is absolute temperature). However, within 0.3 s, individual gp120-CD4 bonds undergo rapid destabilization accompanied by a shortened lifetime and a lowered tensile strength. This destabilization is significantly enhanced by the coreceptor CCR5, not by CXCR4 or fusion inhibitors, which suggests that it is directly related to a conformational change in the gp120-CD4 bond. These measurements highlight the instability and low tensile strength of gp120-receptor bonds, uncover a synergistic role for CCR5 in the progression of the gp120-CD4 bond, and suggest that the cell-virus adhesion complex is functionally arranged about a long-lived gp120-coreceptor bond.

Interference of HIV-1 Nef in the sphingomyelin transduction pathway activated by tumour necrosis factor-α in human glial cells

AIDS ◽  
1997 ◽  
Vol 11 (1) ◽  
pp. F1-F7 ◽  
Author(s):  
Alain Richard ◽  
Gilles Robichaud ◽  
Réjean Lapointe ◽  
Sylvain Bourgoin ◽  
André Darveau ◽  
...  
Keyword(s):  
Tumour Necrosis Factor ◽  
Glial Cells ◽  
Tumour Necrosis ◽  
Transduction Pathway ◽  
Tumour Necrosis Factor Α ◽  
Factor Α ◽  
Hiv 1 ◽  
Necrosis Factor

MEGAKARYOCYTIC DIFFERENTIATION OF HIMeg-1 CELLS INDUCED BY INTERFERON γ AND TUMOUR NECROSIS FACTOR α BUT NOT BY THROMBOPOIETIN

Cytokine ◽  
1998 ◽  
Vol 10 (11) ◽  
pp. 880-889 ◽  
Author(s):  
Jian Li ◽  
Robert S. Franco ◽  
Yisheng Wang ◽  
Hui-Qi Pan ◽  
Dan Eaton ◽  
...  
Keyword(s):  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Interferon Γ ◽  
Tumour Necrosis Factor Α ◽  
Megakaryocytic Differentiation ◽  
Factor Α ◽  
Necrosis Factor

scholarly journals Role of Cholesterol in Human Immunodeficiency Virus Type 1 Envelope Protein-Mediated Fusion with Host Cells

2002 ◽  
Vol 76 (22) ◽  
pp. 11584-11595 ◽  
Author(s):  
Mathias Viard ◽  
Isabella Parolini ◽  
Massimo Sargiacomo ◽  
Katia Fecchi ◽  
Carlo Ramoni ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Membrane Fusion ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Laser Scanning Microscopy ◽  
Host Cells ◽  
Cholesterol Depletion ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT In this study we examined the effects of target membrane cholesterol depletion and cytoskeletal changes on human immunodeficiency virus type 1 (HIV-1) Env-mediated membrane fusion by dye redistribution assays. We found that treatment of peripheral blood lymphocytes (PBL) with methyl-β-cyclodextrin (MβCD) or cytochalasin reduced their susceptibility to membrane fusion with cells expressing HIV-1 Env that utilize CXCR4 or CCR5. However, treatment of human osteosarcoma (HOS) cells expressing high levels of CD4 and coreceptors with these agents did not affect their susceptibility to HIV-1 Env-mediated membrane fusion. Removal of cholesterol inhibited stromal cell-derived factor-1α- and macrophage inflammatory protein 1β-induced chemotaxis of both PBL and HOS cells expressing CD4 and coreceptors. The fusion activity as well as the chemotactic activity of PBL was recovered by adding back cholesterol to these cells. Confocal laser scanning microscopy analysis indicated that treatment of lymphocytes with MβCD reduced the colocalization of CD4 or of CXCR4 with actin presumably in microvilli. These findings indicate that, although cholesterol is not required for HIV-1 Env-mediated membrane fusion per se, its depletion from cells with relatively low coreceptor densities reduces the capacity of HIV-1 Env to engage coreceptor clusters required to trigger fusion. Furthermore, our results suggest that coreceptor clustering may occur in microvilli that are supported by actin polymerization.

scholarly journals Tumour necrosis factor-α mediates blood—brain barrier damage in HIV-1 infection of the central nervous system

1992 ◽  
Vol 1 (3) ◽  
pp. 191-196 ◽  
Author(s):  
M. K. Sharief ◽  
M. Ciardi ◽  
E. J. Thompson ◽  
F. Sorice ◽  
F. Rossi ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Tumour Necrosis ◽  
Brain Barrier ◽  
Tumour Necrosis Factor Α ◽  
Blood Brain ◽  
Tnf Α ◽  
Factor Α ◽  
Hiv 1 ◽  
Blood Brain Barrier Damage ◽  
Necrosis Factor

The pathogenesis of brain inflammation and damage by human immunodeficiency virus (HIV) infection is unclear. Because blood–brain barrier damage and impaired cerebral perfusion are common features of HIV-1 infection, we evaluated the role of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in mediating disruption of the blood–brain barrier. Levels of TNF-α were more elevated in cerebrospinal fluid (CSF) than in serum of HIV-1 infected patients and were mainly detected in those patients who had neurologic involvement. Intrathecal TNF-α levels correlated with signs of blood–brain barrier damage, manifested by high CSF to serum albumin quotient, and with the degree of barrier impairment. In contrast, intrathecal IL-1β levels did not correlate with blood-brain barrier damage in HIV-1 infected patients. TNF-α seems to be related to active neural inflammation and to blood–brain barrier damage. The proinflammatory effects of TNF-α in the nervous system are dissociated from those of IL-1β.

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