scholarly journals Iκκ Mediates NF-κB Activation in Human Immunodeficiency Virus-Infected Cells

1999 ◽  
Vol 73 (5) ◽  
pp. 3893-3903 ◽  
Author(s):  
Susana Asin ◽  
Julie A. Taylor ◽  
Sergey Trushin ◽  
Gary Bren ◽  
Carlos V. Paya

ABSTRACT Human monocytes and macrophages are persistent reservoirs of human immunodeficiency virus (HIV) type-1. Persistent HIV infection of these cells results in increased levels of NF-κB in the nucleus secondary to increased IκBα, IκBβ, and IκBɛ degradation, a mechanism postulated to regulate viral persistence. To characterize the molecular mechanisms regulating HIV-mediated degradation of IκB, we have sought to identify the regulatory domains of IκBα targeted by HIV infection. Using monocytic cells stably expressing different transdominant molecules of IκBα, we determined that persistent HIV infection of these cells targets the NH2 but not the COOH terminus of IκBα. Further analysis demonstrated that phosphorylation at S32 and S36 is necessary for HIV-dependent IκBα degradation and NF-κB activation. Of the putative N-terminal IκBα kinases, we demonstrated that the Iκκ complex, but not p90 rsk , is activated by HIV infection and mediates HIV-dependent NF-κB activation. Analysis of viral replication in cells that constitutively express IκBα negative transdominant molecules demonstrated a lack of correlation between virus-induced NF-κB (p65/p50) nuclear translocation and degree of viral persistence in human monocytes.

Blood ◽  
1997 ◽  
Vol 89 (8) ◽  
pp. 2842-2848 ◽  
Author(s):  
Y. Taoufik ◽  
O. Lantz ◽  
C. Wallon ◽  
A. Charles ◽  
E. Dussaix ◽  
...  

Abstract Interleukin-12 (IL-12), a cytokine with in vitro and in vivo immunomodulatory effects, is produced mostly by activated monocytes and macrophages. To study the effect of human immunodeficiency virus (HIV) infection on IL-12 production, we investigated the expression of IL-12 at mRNA and protein levels by human monocytes preincubated with HIV-gp120. In these conditions, we show that monocytes have a decreased ability to express IL-12 mRNA subunits and to produce IL-12 p40 and bioactive p70 proteins in response to Staphylococcus aureus strain cowan I (SAC). We showed that in human monocyte cultures, HIV-gp120 induces a significant IL-10 synthesis, which in turn inhibits IL-12 subunits mRNA accumulation and protein secretion after SAC-activation. Similar data were obtained with human macrophages. These results suggest that, during HIV infection, gp120 induces in uninfected monocytes and macrophages IL-10/IL-12 disregulation, which can alter immune response.


2002 ◽  
Vol 76 (16) ◽  
pp. 8118-8123 ◽  
Author(s):  
Yael D. Korin ◽  
David G. Brooks ◽  
Stephen Brown ◽  
Andrew Korotzer ◽  
Jerome A. Zack

ABSTRACT Human immunodeficiency virus (HIV) replication is linked to cellular gene transcription and requires target cell activation. The latent reservoir of HIV-1 in quiescent T cells is thought to be a major obstacle to clearance of infection by highly active antiretroviral therapy (HAART). Thus, identification of agents that can induce expression of latent virus may, in the presence of HAART, allow elimination of the infected cells by the immune response. We previously used the SCID-hu (Thy/Liv) mouse model to establish that activation-inducible HIV can be generated at high frequency during thymopoiesis. Latently infected mature thymocytes can be exported into the periphery, providing an efficient primary cell model to determine cellular activation signals that induce renewed expression of latent virus. Here we characterized the effects of prostratin, a non-tumor-promoting phorbol ester, on primary human peripheral blood lymphocytes (PBLs) and assessed its ability to reactivate latent HIV infection from thymocytes and PBLs in the SCID-hu (Thy/Liv) model. Prostratin stimulation alone did not induce proliferation of quiescent PBLs; however, it could provide a secondary signal in the context of T-cell receptor stimulation or a primary activation signal in the presence of CD28 stimulation to induce T-cell proliferation. While prostratin alone was not sufficient to allow de novo HIV infection, it efficiently reactivated HIV expression from latently infected cells generated in the SCID-hu mouse. Our data indicate that prostratin alone is able to specifically reactivate latent virus in the absence of cellular proliferation, making it an attractive candidate for further study as an adjunctive therapy for the elimination of the latent HIV reservoir.


1995 ◽  
Vol 181 (4) ◽  
pp. 1493-1505 ◽  
Author(s):  
J L Ho ◽  
S He ◽  
A Hu ◽  
J Geng ◽  
F G Basile ◽  
...  

Infection with a sexually transmitted disease (STD) increases the risk for human immunodeficiency virus (HIV) infection. Polymorphonuclear leukocytes (PMNs) are recruited into the genital tract by STD pathogens, such as Chlamydia trachomatis. Semen of HIV-infected men contains HIV associated with mononuclear cells. This study investigated the interaction among PMNs from HIV-uninfected persons, C. trachomatis, and HIV-infected cells and examined the mechanisms for enhanced HIV replication. We demonstrated that PMNs from HIV-seronegative donors induced HIV replication in mononuclear cells from 17 HIV-infected patients in medium without exogenous IL-2. HIV in the cell-free supernatants from cocultures of PMNs and patients' peripheral blood mononuclear cells (PBMCs) was replication competent, as indicated by their capacity to propagate HIV in a second round of culture using PBMCs from HIV-seronegative individuals and by the fact that proviral DNA was found in these cells. PMNs from HIV-seronegative donors increased HIV replication over 100-fold in chronically HIV-infected cell lines of the monocytic, T, and B cell lineages. Moreover, PMNs increased U1 cells' production of p24 antigen by as much as ninefold when compared with U1 cells cocultured with PBMCs. The addition of C. trachomatis to PMN and U1 coculture increased HIV replication by an additional ninefold at 24 h, whereas C. trachomatis alone had no effect on p24 antigen production by U1 cells. Thus, C. trachomatis serves not only to recruit PMNs, but also to interact with PMNs to increase HIV replication. HIV replication is triggered by contact of HIV-infected cells with PMNs, by the generation of reactive oxygen intermediates (ROIs), and by soluble factors such as TNF-alpha and IL-6. This is based on the findings that production of p24 antigen, IL-6, and TNF-alpha induced by PMNs is abrogated by disrupting or partitioning PMNs from HIV-infected cells; is inhibited by superoxide dismutase and catalase, enzymes that destroy ROIs; is enhanced by differentiated HL60 cells capable of producing ROIs; and is induced by PMNs tested negative for CMV. Furthermore, the production of ROIs is independent of HIV infection of mononuclear cells, since PMNs cocultured with HIV-uninfected parental monocytic and T cell lines generated ROIs. Therefore, the increased risk for acquiring HIV infection associated with chlamydia cervicitis may be related to the local recruitment of PMNs by C. trachomatis and the induction of infectious virus from mononuclear cells present in semen. These observations provide a rationale for strategies to reduce HIV transmission by control of STD.


2008 ◽  
Vol 82 (24) ◽  
pp. 12291-12303 ◽  
Author(s):  
Richard Pearson ◽  
Young Kyeung Kim ◽  
Joseph Hokello ◽  
Kara Lassen ◽  
Julia Friedman ◽  
...  

ABSTRACT The molecular mechanisms utilized by human immunodeficiency virus (HIV) to enter latency are poorly understood. Following the infection of Jurkat T cells with lentiviral vectors that express Tat in cis, gene expression is progressively silenced. Silencing is greatly enhanced when the lentiviral vectors carry an attenuated Tat gene with the H13L mutation. Individual clones of lentivirus-infected cells showed a wide range of shutdown rates, with the majority showing a 50% silencing frequency between 30 to 80 days. The silenced clones characteristically contained a small fraction (0 to 15%) of activated cells that continued to express d2EGFP. When d2EGFP+ and d2EGFP− cell populations were isolated from the shutdown clones, they quickly reverted to the original distribution of inactive and active cells, suggesting that the d2EGFP+ cells arise from stochastic fluctuations in gene expression. The detailed analysis of transcription initiation and elongation using chromatin immunoprecipitation (ChIP) assays confirms that Tat levels are restricted in the latently infected cells but gradually rise during proviral reactivation. ChIP assays using clones of latently infected cells demonstrate that the latent proviruses carry high levels of deacetylated histones and trimethylated histones. In contrast, the cellular genes IκBα and GAPDH had high levels of acetylated histones and no trimethylated histones. The levels of trimethylated histone H3 and HP1-α associated with HIV proviruses fell rapidly after tumor necrosis factor alpha activation. The progressive shutdown of HIV transcription following infection suggests that epigenetic mechanisms targeting chromatin structures selectively restrict HIV transcription initiation. This decreases Tat production below the levels that are required to sustain HIV gene expression.


1987 ◽  
Vol 1 (3) ◽  
pp. 381-395 ◽  
Author(s):  
Beverly Ryan ◽  
Edward Connor ◽  
Anthony Minnefor ◽  
Frank Desposito ◽  
James Oleske

2020 ◽  
Vol 18 (5) ◽  
pp. 381-386
Author(s):  
Yusuke Yoshino ◽  
Ichiro Koga ◽  
Yoshitaka Wakabayashi ◽  
Takatoshi Kitazawa ◽  
Yasuo Ota

Background: The change in the prevalence of hypogonadism with age in men with human immunodeficiency virus (HIV) infection is subject to debate. Objective: To address this issue, we diagnosed hypogonadism based on serum levels of free testosterone (fTST) rather than total testosterone which is thought to be an inaccurate indicator. We also determined the relationship between age and fTST levels and identified risk factors for hypogonadism in men with HIV infection. Method: We retrospectively reviewed fTST levels and associated clinical factors in 71 wellcontrolled HIV-infected men who were treated at Teikyo University Hospital between April 2015 and March 2016 and who had data available on serum fTST levels, measured >6 months after starting antiretroviral therapy. fTST was measured using radioimmunoassay on blood samples collected in the morning. Risk factors for hypogonadism were identified using Welch’s t-test and multiple regression analysis. Results: The men had a mean (± standard deviation) age of 47.4 ± 13.6 years, and mean (± standard deviation) serum fTST level of 13.0 ± 6.1 pg/mL. Fifteen (21.1%) men had hypogonadism based on a fTST <8.5 pg/mL. Serum fTST levels significantly decreased with age (−0.216 pg/mL/year). Older age and low hemoglobin levels were identified as risk factors for hypogonadism. Conclusion: The men in the study experienced a more rapid decline in fTST levels with age than men in the general population (−0.161 pg/mL/year). Serum fTST levels in men with HIV infection should be monitored, especially in older men and those with low hemoglobin levels.


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