scholarly journals CXCR4-mediated T cell apoptosis in human immunodeficiency virus infection

2004 ◽  
Vol 85 (6) ◽  
pp. 1471-1478 ◽  
Author(s):  
Anne-Zélie Decrion ◽  
Audrey Varin ◽  
Jean-Marie Estavoyer ◽  
Georges Herbein
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cell Apoptosis ◽  
Mononuclear Cells ◽  
Viral Envelope ◽  
T Cell Apoptosis ◽  
Immunodeficiency Virus

Mechanisms of CXCR4-mediated T lymphocyte apoptosis in human immunodeficiency virus (HIV) infection are poorly understood. The authors used peripheral blood mononuclear cells isolated from HIV type 1-infected subjects and assessed both CD4+ and CD8+ T cell apoptosis in the presence and absence of CXCR4 blockade by AMD3100. Both CD4+ and CD8+ T cell apoptosis could be inhibited by CXCR4 blockade, mostly in acquired immunodeficiency syndrome subjects and more weakly in asymptomatic HIV-positive subjects, and depended only partially on the syncytium-inducing/non-syncytium-inducing viral envelope phenotype. Immune activation of CD8+, but not CD4+, T cells was CXCR4-dependent, resulting in increased T cell apoptosis. In the presence of monocyte-derived macrophages, CXCR4-mediated apoptosis targeted mostly CD8+ T cells, with CD4+ T cells being more weakly affected. Several immune and viral factors thus play a role in CXCR4-mediated T cell apoptosis in HIV infection: CD4/CD8 phenotype, viral envelope phenotype, T cell activation and T cell–macrophage intercellular contacts.

scholarly journals Helicobacter pylori VacA Toxin Inhibits Human Immunodeficiency Virus Infection of Primary Human T Cells

2006 ◽  
Vol 80 (23) ◽  
pp. 11767-11775 ◽  
Author(s):  
Kyra Oswald-Richter ◽  
Victor J. Torres ◽  
Mark S. Sundrud ◽  
Scott E. VanCompernolle ◽  
Timothy L. Cover ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Helicobacter Pylori ◽  
T Cell ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Atp Depletion ◽  
Mitogen Activated Protein Kinase ◽  
Cytokine Signaling ◽  
Immunodeficiency Virus

ABSTRACT Human CD4+ T cells are major targets for human immunodeficiency virus (HIV) infection. Resting T cells are resistant to HIV infection unless activated through the T-cell receptor (TCR) or by cytokine signals. How T-cell signaling promotes susceptibility of T cells to HIV infection remains poorly understood. Here we demonstrate that the VacA toxin produced by Helicobacter pylori can inhibit HIV infection of primary T cells, stimulated through the TCR or by cytokines alone. This activity of VacA was dependent on its ability to form membrane channels. VacA suppressed HIV infection of T cells at a stage after viral entry, post-reverse transcription and pre-two-long-terminal-repeat circle formation, similar to the cytokine signaling inhibitor rapamycin. Mechanistically, neither VacA nor rapamycin inhibited the activation of cytokine signal transduction components (STAT5, p42/44 mitogen-activated protein kinase, or p38), but both blocked activation of key regulatory proteins required for G1 cell cycle transition. In contrast to rapamycin, VacA did not suppress phosphorylation of p70 S6 kinase but caused mitochondrial depolarization and ATP depletion within primary T cells. These results suggest that VacA inhibits T-cell activation and HIV infection via a novel mechanism. Identifying the host cell targets of VacA could be useful for elucidating the HIV life cycle within primary T cells.

scholarly journals Loss of CD4+ T Cells in Human Immunodeficiency Virus Type 1-Infected Chimpanzees Is Associated with Increased Lymphocyte Apoptosis

1998 ◽  
Vol 72 (6) ◽  
pp. 4623-4632 ◽  
Author(s):  
Ian C. Davis ◽  
Marc Girard ◽  
Patricia N. Fultz
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Human Immunodeficiency Virus Type ◽  
Cell Apoptosis ◽  
T Cell Apoptosis ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Supportive evidence that apoptosis contributes to loss of CD4+ lymphocytes in human immunodeficiency virus type 1 (HIV-1)-infected humans comes from an apparent lack of abnormal apoptosis in apathogenic lentivirus infections of nonhuman primates, including HIV-1 infection of chimpanzees. Two female chimpanzees were inoculated, one cervically and the other intravenously, with HIV-1 derived from the LAI/LAV-1b strain, which was isolated from a chimpanzee infected with the virus for 8 years. Within 6 weeks of infection, both recipient chimpanzees developed a progressive loss of CD4+ T cells which correlated with persistently high viral burdens and increased levels of CD4+ T-cell apoptosis both in vitro and in vivo. Lymph nodes from both animals also revealed evidence of immune hyperactivation. Intermediate levels of T-cell apoptosis in both peripheral blood and lymph nodes were seen in a third chimpanzee that had been infected with the LAI/LAV-1b strain for 9 years; this animal has maintained depressed CD4/CD8 T-cell ratios for the last 3 years. Similar analyses of cells from 4 uninfected animals and 10 other HIV-1-infected chimpanzees without loss of CD4+ cells revealed no difference in levels of apoptosis in these two control groups. These results demonstrate a correlation between immune hyperactivation, T-cell apoptosis, and chronic loss of CD4+ T cells in HIV-1-infected chimpanzees, providing additional evidence that apoptosis is an important factor in T-cell loss in AIDS. Furthermore, the results show that some HIV-1 strains are pathogenic for chimpanzees and that this species is not inherently resistant to HIV-1-induced disease.

scholarly journals Interleukin 7 Increases Human Immunodeficiency Virus Type 1 LAI-Mediated Fas-Induced T-Cell Death

2005 ◽  
Vol 79 (5) ◽  
pp. 3195-3199 ◽  
Author(s):  
Jean-Daniel Lelièvre ◽  
Frédéric Petit ◽  
Damien Arnoult ◽  
Jean-Claude Ameisen ◽  
Jérôme Estaquier
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Hiv Infection ◽  
Cell Infection ◽  
Interleukin 7 ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Fas-mediated T-cell death is known to occur during human immunodeficiency virus (HIV) infection. In this study, we found that HIV type 1 LAI (HIV-1LAI) primes CD8+ T cells from healthy donors for apoptosis, which occurs after Fas ligation. This effect is counteracted by a broad caspase inhibitor (zVAD-fmk). Fas-mediated cell death does not depend on CD8+ T-cell infection, because it occurred in the presence of reverse transcriptase inhibitors. However, purified CD8+ T cells are sensitive to Fas only in the presence of soluble CD4. Finally, we found that interleukin 7 (IL-7) increases Fas-mediated CD4+ and CD8+ T-cell death induced by HIV-1LAI. Since high levels of IL-7 are a marker of poor prognosis during HIV infection, our data suggest that enhancement of Fas-mediated T-cell death by HIV-1LAI and IL-7 is one of the mechanisms involved in progression to AIDS.

scholarly journals Selective anergy of V beta 8+ T cells in human immunodeficiency virus-infected individuals.

1994 ◽  
Vol 179 (2) ◽  
pp. 413-424 ◽  
Author(s):  
G Dadaglio ◽  
S Garcia ◽  
L Montagnier ◽  
M L Gougeon
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cd8 T Cells ◽  
Clinical Status ◽  
Interleukin 2 ◽  
Cell Subset ◽  
T Cell Subset ◽  
Immunodeficiency Virus

We have analyzed the V beta usage by CD4+ and CD8+ T cells from human immunodeficiency virus (HIV)-infected individuals in response to an in vitro stimulation with the superantigenic erythrogenic toxin A (ETA) of Streptococcus pyogenes. ETA amplifies specifically CD4+ and CD8+ T cells from control donors expressing the V beta 8 and the V beta 12 elements. When peripheral T cells from asymptomatic HIV-infected individuals were stimulated with ETA, there was a complete lack of activation of the V beta 8+ T cell subset, whereas the V beta 12+ T cell subset responded normally to the superantigen. This V beta-specific anergy, which was also observed in response to staphylococcal enterotoxin E (SEE), affected both CD4+ and CD8+ T cells and represented an intrinsic functional defect rather than a specific lack of response to bacterial superantigens since it was also observed after a stimulation with V beta 8 monoclonal antibodies. The V beta 8 anergic T cells did not express interleukin 2 receptors (IL-2Rs) and failed to proliferate in response to exogenous IL-2 or IL-4, suggesting that this anergy was not a reversible process, at least by the use of these cytokines. The unresponsiveness of the V beta 8 T cell subset is frequent since it was found in 56% of the patients studied, and comparison of the clinical status of responder vs. anergic patients indicated that the only known common factor between them was HIV infection. In addition, it is noteworthy that the anergy of the V beta 8 subset may be a very early phenomenon since it was found in a patient at Centers for Disease Control stage I of the disease. These data provide evidence that a dominant superantigen may be involved in the course of HIV infection and that the contribution of HIV has to be considered.

scholarly journals Antiphosphatidylserine antibodies in human immunodeficiency virus-1 patients with evidence of T-cell apoptosis and mediate antibody- dependent cellular cytotoxicity [see comments]

Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5185-5195 ◽  
Author(s):  
F Silvestris ◽  
MA Frassanito ◽  
P Cafforio ◽  
D Potenza ◽  
M Di Loreto ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Cell Apoptosis ◽  
Clinical Feature ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
T Cell Apoptosis ◽  
Immunodeficiency Virus ◽  
Hiv 1

Serum reactivities to a panel of phospholipid antigens, including cardiolipin (CL), phosphatidylserine (PS), sphingomyelin, phosphatidylcholine, and phosphatidylethanolamine, were measured by enzyme-linked immunosorbent assay in 196 human immunodeficiency virus- l+ (HIV-1+) patients with CDC II to IVC clinical disease. Significant levels of IgG to CL, PS, or both were observed in 23 patients lacking evidence of thrombophilic events or any peculiar clinical feature of HIV-1 infection. Fluorescence-activated cell sorting analyses showed that in vitro apoptosis of T cells was increased in patients with high serum anti-PS IgG, whereas the overexpression of Fas/Apo-1 marker was detected in all patients regardless of their antiphospholipid reactivities. Macrophages from patients with significant titers of anti- PS IgG antibodies were not activated by the presence of apoptotic CEM lymphoblasts or by purified anti-PS IgG from the same patients. By contrast, these antibodies greatly improved the effector functions of autologous macrophages in antibody-dependent cellular cytotoxicity (ADCC) assays using 51Cr-labeled CEM cells, whereas polyspecific IgG were unable to induce an equivalent cytotoxicity in all instances. An increasing effect on ADCC was also observed in tests using macrophages from healthy controls to CEM coated with anti-PS IgG. These results support a potential correlation of anti-PS specificity with T-cell apoptosis in HIV-1 infection. Because PS is exteriorized by apoptotic lymphocytes, its persistence may stimulate antibodies which cooperate with macrophages in the clearance of dead cells by an enhanced ADCC mechanism. This interpretation could explain the absence of thrombophilia in HIV-1+ patients with serum elevations of antiphospholipid reactivities.

scholarly journals Viral Suppression and Immune Restoration in the Gastrointestinal Mucosa of Human Immunodeficiency Virus Type 1-Infected Patients Initiating Therapy during Primary or Chronic Infection

2006 ◽  
Vol 80 (16) ◽  
pp. 8236-8247 ◽  
Author(s):  
Moraima Guadalupe ◽  
Sumathi Sankaran ◽  
Michael D. George ◽  
Elizabeth Reay ◽  
David Verhoeven ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Microarray Analysis ◽  
Dna Microarray ◽  
Peripheral Blood ◽  
Viral Suppression ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Although the gut-associated lymphoid tissue (GALT) is an important early site for human immunodeficiency virus (HIV) replication and severe CD4+ T-cell depletion, our understanding is limited about the restoration of the gut mucosal immune system during highly active antiretroviral therapy (HAART). We evaluated the kinetics of viral suppression, CD4+ T-cell restoration, gene expression, and HIV-specific CD8+ T-cell responses in longitudinal gastrointestinal biopsy and peripheral blood samples from patients initiating HAART during primary HIV infection (PHI) or chronic HIV infection (CHI) using flow cytometry, real-time PCR, and DNA microarray analysis. Viral suppression was more effective in GALT of PHI patients than CHI patients during HAART. Mucosal CD4+ T-cell restoration was delayed compared to peripheral blood and independent of the time of HAART initiation. Immunophenotypic analysis showed that repopulating mucosal CD4+ T cells were predominantly of a memory phenotype and expressed CD11α, αEβ7, CCR5, and CXCR4. Incomplete suppression of viral replication in GALT during HAART correlated with increased HIV-specific CD8+ T-cell responses. DNA microarray analysis revealed that genes involved in inflammation and cell activation were up regulated in patients who did not replenish mucosal CD4+ T cells efficiently, while expression of genes involved in growth and repair was increased in patients with efficient mucosal CD4+ T-cell restoration. Our findings suggest that the discordance in CD4+ T-cell restoration between GALT and peripheral blood during therapy can be attributed to the incomplete viral suppression and increased immune activation and inflammation that may prevent restoration of CD4+ T cells and the gut microenvironment.

CD8 T-Cell Infiltration in Extravascular Tissues of Patients With Human Immunodeficiency Virus Infection. Interleukin-15 Upmodulates Costimulatory Pathways Involved in the Antigen-Presenting Cells–T-Cell Interaction

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1277-1286 ◽  
Author(s):  
Carlo Agostini ◽  
Renato Zambello ◽  
Monica Facco ◽  
Alessandra Perin ◽  
Francesco Piazza ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Binding Proteins ◽  
Antigen Presenting Cells ◽  
Cd8 T Cell ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Antigen Presenting

Interleukin (IL)-15 regulates the proliferative activity of the CD8+ T-cell pool in human immunodeficiency virus (HIV)-infected patients, thereby contributing to the maintenance of the CD8+ T-cell–mediated immune response against HIV in extravascular tissues, including the lung. However, the effects of IL-15 on antigen-presenting cells (APC) during HIV infection are still unclear. In this study, we evaluated whether IL-15 regulates the macrophage stimulatory pathways governing inflammatory events that take place in the lung of patients with HIV infection. As a first step we evaluated the in vitro effects of IL-15 on lung macrophages retrieved from the respiratory tract of eight normal subjects. Although macrophages from uninfected individuals expressed the IL-15 binding proteins (IL-15R and the common γc) at resting conditions, they did not express IL-15 messenger RNA (mRNA). However, a 24-hour stimulation with IL-15 induced the expression of interferon-γ (IFN-γ) and IL-15 itself, suggesting a role for this cytokine in the activation of the pulmonary macrophage pool during inflammation. As a confirmation of the role of IL-15 in this setting, at resting conditions, alveolar macrophages of patients with HIV infection and T-cell alveolitis expressed IL-15, IFN-γ, and IL-15 binding proteins; showed an upmodulation of costimulatory molecules, B7 and CD72, which are involved in the APC of macrophages; and behaved as effective accessory cells because they elicited a strong proliferation of T cells. The accessory effect was inhibited by pretreatment with anti-CD72, anti-B7 (CD80 and CD86), and anti–IL-15 monoclonal antibodies (MoAb). We then investigated the relationship between IL-15 and the expression of costimulatory molecules by macrophages. A 24-hour stimulation of IL-15R+/γc+ macrophages with IL-15 upregulated the expression of CD80 and CD86. The evidence that IL-15 upregulates the expression of coligands that favor the contact between T cells and APC, per se, triggers T-cell activation and proliferation and acts as a chemoattractant for T cells, suggests that IL-15 plays a key role in Tc1-mediated defense mechanisms taking place in extravascular tissues of patients with HIV disease.

scholarly journals Overexpression of a Novel Lymphocyte Population, Positive for an Intracellular CD14-Like Antigen, in Patients Positive for Human Immunodeficiency Virus Type 1

2004 ◽  
Vol 11 (6) ◽  
pp. 1040-1044 ◽  
Author(s):  
Dan Turner ◽  
Michael Hoffman ◽  
Israel Yust ◽  
Mordechai Fried ◽  
Margalit Bleiberg ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cell Population ◽  
Human Peripheral Blood ◽  
Soluble Form ◽  
Lymphocyte Population ◽  
Cellular Marker ◽  
Immunodeficiency Virus

ABSTRACT CD14, originally recognized as a lipopolysaccharide (LPS) receptor, has recently been implicated in the process of T-cell suppression and apoptosis. Its soluble form has been shown to bind, in vitro, to human T cells, a process that may carry a negative signal onto these cells. We recently described a novel lymphocyte population in human peripheral blood, a population that expresses an intracellular CD14-like antigen. This novel T-cell population, composed mainly of CD8 cells and of very few CD4 cells, was found to be greatly enhanced in asymptomatic, untreated human immunodeficiency virus (HIV)-positive individuals. In the present study, we further characterized this cell population and found that it differed from other CD8 subpopulations associated with HIV infection such as CD8/CD38. In addition, we followed HIV patients under conditions of highly active antiretroviral therapy (HAART) and observed two groups of patients: patients in whom the CD14-like positive-testing T cells returned to normal within 1 to 3 months, and patients in whom it did not, in spite of a significant plasma HIV-RNA viral load decrease. Thus, this new CD14-like positive-testing lymphocyte population may represent an interesting and important component of the cellular events associated with HIV infection. On the basis of its modulation following HAART, we speculate that it may be used, in the future, as a drug-monitoring cellular marker in antiretroviral treatment.

scholarly journals CD8+ T lymphocytes provide helper activity for IgE synthesis in human immunodeficiency virus-infected patients with hyper-IgE.

1995 ◽  
Vol 181 (1) ◽  
pp. 423-428 ◽  
Author(s):  
R Paganelli ◽  
E Scala ◽  
I J Ansotegui ◽  
C M Ausiello ◽  
E Halapi ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cd4 Cells ◽  
In Vitro Synthesis ◽  
Immunodeficiency Virus ◽  
Ige Synthesis

Increased levels of serum IgE and eosinophilia have been described in human immunodeficiency virus (HIV) infection, almost exclusively in patients with CD4+ cell count < 200 cells/microliters. IgE production is regulated by CD4+ T helper type 2 (Th-2) lymphocytes, producing interleukin 4 (IL-4) and expressing a ligand for the B cell-specific CD40 molecule (CD40 ligand [L]). A shift to a Th-2-like pattern of cytokine secretion has been postulated to be associated with progression toward acquired immunodeficiency syndrome (AIDS). We studied three AIDS patients with very high levels of IgE and almost complete depletion of CD4+ lymphocytes, suggesting that IgE synthesis could not be driven by CD4+ cells. IgE in vitro synthesis by cells from such patients was, however, inhibited by anti-IL-4. We show that both CD8+ T cell lines and the majority of CD8+ T cells clones derived from these patients produce IL-4, IL-5, and IL-6 in half of the cases together with interferon gamma (IFN-gamma). 44% of CD8+ T cell clones expressed a CD40L, and the supernatants of the clones were capable of inducing IgE synthesis by normal B cells costimulated with anti-CD40. CD8+ T cells in these patients therefore functionally mimic Th-2 type cells and may account for hyper-IgE and eosinophilia in the absence of CD4+ cells. The presence of such CD8+ cells may also provide a source of IL-4 directing the development of predominant Th-2 responses in HIV infection.

Sign in / Sign up

Export Citation Format

Share Document