scholarly journals Human Immunodeficiency Virus Type 1 Vpr Impairs Dendritic Cell Maturation and T-Cell Activation: Implications for Viral Immune Escape

2005 ◽  
Vol 79 (13) ◽  
pp. 7990-8003 ◽  
Author(s):  
Biswanath Majumder ◽  
Michelle L. Janket ◽  
Elizabeth A. Schafer ◽  
Keri Schaubert ◽  
Xiao-Li Huang ◽  
...  

ABSTRACT Antigen presentation and T-cell activation are dynamic processes involving signaling molecules present in both APCs and T cells. Effective APC function and T-cell activation can be compromised by viral immune evasion strategies, including those of human immunodeficiency virus type 1 (HIV-1). In this study, we determined the effects of HIV-1 Vpr on one of the initial target of the virus, dendritic cells (DC), by investigating DC maturation, cytokine profiling, and CD8-specific T-cell stimulation function followed by a second signal. Vpr impaired the expression of CD80, CD83, and CD86 at the transcriptional level without altering normal cellular transcription. Cytokine profiling indicated that the presence of Vpr inhibited production of interleukin 12 (IL-12) and upregulated IL-10, whereas IL-6 and IL-1β were unaltered. Furthermore, DC infected with HIV-1 vpr + significantly reduced the activation of antigen-specific memory and recall cytotoxic-T-lymphocyte responses. Taken together, these results indicate that HIV-1 Vpr may in part be responsible for HIV-1 immune evasion by inhibiting the maturation of costimulatory molecules and cytokines essential for immune activation.

2018 ◽  
Vol 219 (7) ◽  
pp. 1084-1094 ◽  
Author(s):  
Eileen P Scully ◽  
Monica Gandhi ◽  
Rowena Johnston ◽  
Rebecca Hoh ◽  
Ainsley Lockhart ◽  
...  

Abstract Plasma human immunodeficiency virus type 1 (HIV-1) RNA levels in women are lower early in untreated HIV-1 infection compared with those in men, but women have higher T-cell activation and faster disease progression when adjusted for viral load. It is not known whether these sex differences persist during effective antiretroviral therapy (ART), or whether they would be relevant for the evaluation and implementation of HIV-1 cure strategies. We prospectively enrolled a cohort of reproductive-aged women and matched men on suppressive ART and measured markers of HIV-1 persistence, residual virus activity, and immune activation. The frequency of CD4+ T cells harboring HIV-1 DNA was comparable between the sexes, but there was higher cell-associated HIV-1 RNA, higher plasma HIV-1 (single copy assay), and higher T-cell activation and PD-1 expression in men compared with women. These sex-related differences in immune phenotype and HIV-1 persistence on ART have significant implications for the design and measurement of curative interventions.


2005 ◽  
Vol 79 (7) ◽  
pp. 4396-4406 ◽  
Author(s):  
Jiguo Chen ◽  
Tom Malcolm ◽  
Mario C. Estable ◽  
Robert G. Roeder ◽  
Ivan Sadowski

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) replication is coupled to T-cell activation through its dependence on host cell transcription factors. Despite the enormous sequence variability of these factors, several cis elements for host factors are highly conserved within the 5′ long terminal repeats (LTRs) of viruses from AIDS patients; among these is the RBEIII upstream element for the Ras response element binding factor 2 (RBF-2). Here we show that RBF-2 is comprised of a USF1/USF2 heterodimer and TFII-I, which bind cooperatively to RBEIII. Recombinant USF1/USF2 binds to the RBEIII core sequence 160-fold less efficiently than it binds to an E box element, but the interaction with RBEIII is stimulated by TFII-I. Chromosomally integrated HIV-1 LTRs bearing an RBEIII mutation have slightly elevated basal transcription in unstimulated Jurkat cells but are unresponsive to cross-linking of the T-cell receptor or stimulation with phorbol myristate acetate (PMA) and ionomycin. Induction is inhibited by dominant interfering USF and TFII-I but not by the dominant negative I-κB protein. USF1, USF2, and TFII-I bind to the integrated wild-type LTR in unstimulated cells and become phosphorylated during the induction of transcription upon stimulation with PMA. These results demonstrate that USF1/USF2 and TFII-I interact cooperatively at the upstream RBEIII element and are necessary for the induction of latent HIV-1 in response to T-cell activation signals.


2009 ◽  
Vol 83 (22) ◽  
pp. 11830-11846 ◽  
Author(s):  
Mir Munir Ahmed Rahim ◽  
Pavel Chrobak ◽  
Chunyan Hu ◽  
Zaher Hanna ◽  
Paul Jolicoeur

ABSTRACT CD4C/HIVnef transgenic (Tg) mice express Nef in CD4+ T cells and in the cells of the macrophage/monocyte/dendritic lineage, and they develop an AIDS-like disease similar to human AIDS. In these mice, Nef is constitutively expressed throughout life. To rule out the contribution of any developmental defects caused by early expression of Nef, we generated inducible human immunodeficiency virus type 1 (HIV-1) Nef Tg mice by using the tetracycline-inducible system. Faithful expression of the Nef transgene was induced in (CD4C/rtTA × TRE/HIVNef) or (CD4C/rtTA2S-M2 × TRE/HIVNef) double-Tg mice upon doxycycline (DOX) treatment in drinking water. Long-term treatment of these mice with DOX also led to loss, apoptosis, and activation of CD4+ T cells, this latter phenotype being observed even with low levels of Nef. These phenotypes could be transferred by bone marrow (BM) transplantation, indicating a hematopoietic cell autonomous effect. In addition, in mixed Tg:non-Tg BM chimeras, only Tg and not non-Tg CD4+ T cells exhibited an effector/memory phenotype in the absence of lymphopenia. Finally, the DOX-induced double-Tg mice developed nonlymphoid organ diseases similar to those of CD4C/HIVNef Tg mice and of humans infected with HIV-1. These results show for the first time that adult mice are susceptible to the detrimental action of Nef and that Nef-mediated T-cell activation can be independent of lymphopenia. These Tg mice represent a unique model which is likely to be instrumental for understanding the cellular and molecular pathways of Nef action as well as the main characteristics of immune reconstitution following DOX withdrawal.


2008 ◽  
Vol 197 (10) ◽  
pp. 1402-1407 ◽  
Author(s):  
Andrea Kovacs ◽  
Lena Al‐Harthi ◽  
Shawna Christensen ◽  
Wendy Mack ◽  
Mardge Cohen ◽  
...  

2015 ◽  
Vol 96 (6) ◽  
pp. 1463-1477 ◽  
Author(s):  
Mohamed El-Far ◽  
Petronela Ancuta ◽  
Jean-Pierre Routy ◽  
Yuwei Zhang ◽  
Wendy Bakeman ◽  
...  

2005 ◽  
Vol 79 (5) ◽  
pp. 3052-3062 ◽  
Author(s):  
Xiao-Li Huang ◽  
Zheng Fan ◽  
Bonnie A. Colleton ◽  
Rico Buchli ◽  
Hongyi Li ◽  
...  

ABSTRACT Dendritic cells (DCs) loaded with viral peptides are a potential form of immunotherapy of human immunodeficiency virus type 1 (HIV-1) infection. We show that DCs derived from blood monocytes of subjects with chronic HIV-1 infection on combination antiretroviral drug therapy have increases in expression of HLA, T-cell coreceptor, and T-cell activation molecules in response to the DC maturation factor CD40L comparable to those from uninfected persons. Mature DCs (mDCs) loaded with HLA A*0201-restricted viral peptides of the optimal length (9-mer) were more efficient at activating antiviral CD8+ T cells than were immature DCs or peptide alone. Optimal presentation of these exogenous peptides required uptake and vesicular trafficking and was comparable in DCs derived from HIV-1-infected and uninfected persons. Furthermore, DCs from HIV-1-infected and uninfected persons had similar capacities to process viral peptides with C-terminal and N-terminal extensions through their proteasomal and cytosolic pathways, respectively. We conclude that DCs derived from HIV-1-infected persons have similar abilities to process exogenous peptides for presentation to CD8+ T cells as those from uninfected persons. This conclusion supports the use of DCs loaded with synthetic peptides in immunotherapy of HIV-1 infection.


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