scholarly journals Spatially clustered loci with multiple enhancers are frequent targets of HIV-1

2018 ◽  
Author(s):  
Bojana Lucic ◽  
Heng-Chang Chen ◽  
Maja Kuzman ◽  
Eduard Zorita ◽  
Julia Wegner ◽  
...  
Keyword(s):  
T Cells ◽  
Transcriptional Activity ◽  
Nuclear Periphery ◽  
Nuclear Architecture ◽  
Gene Clusters ◽  
Nuclear Pore ◽  
Super Enhancer ◽  
First Time ◽  
Hiv 1

ABSTRACTHIV-1 recurrently targets active genes that are positioned in the outer shell of the nucleus and integrates in the proximity of the nuclear pore compartment. However, the genomic features of these genes and the relevance of their transcriptional activity for HIV-1 integration have so far remained unclear. Here we show that recurrently targeted genes are delineated with super-enhancer genomic elements and that they cluster in specific spatial compartments of the T cell nucleus. We further show that these gene clusters acquire their location at the nuclear periphery during the activation of T cells. The clustering of these genes along with their transcriptional activity are the major determinants of HIV-1 integration in T cells. Our results show for the first time the relevance of the spatial compartmentalization of the genome for HIV-1 integration, thus further strengthening the role of nuclear architecture in viral infection.

scholarly journals The Role of Capsid in HIV-1 Nuclear Entry

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1425
Author(s):  
Anabel Guedán ◽  
Eve R. Caroe ◽  
Genevieve C. R. Barr ◽  
Kate N. Bishop
Keyword(s):  
Nuclear Pore ◽  
Outer Face ◽  
Nuclear Entry ◽  
Nuclear Compartment ◽  
Critical Step ◽  
Technological Advances ◽  
Dividing Cells ◽  
Hiv 1 ◽  
Gain Access

HIV-1 can infect non-dividing cells. The nuclear envelope therefore represents a barrier that HIV-1 must traverse in order to gain access to the host cell chromatin for integration. Hence, nuclear entry is a critical step in the early stages of HIV-1 replication. Following membrane fusion, the viral capsid (CA) lattice, which forms the outer face of the retroviral core, makes numerous interactions with cellular proteins that orchestrate the progress of HIV-1 through the replication cycle. The ability of CA to interact with nuclear pore proteins and other host factors around the nuclear pore determines whether nuclear entry occurs. Uncoating, the process by which the CA lattice opens and/or disassembles, is another critical step that must occur prior to integration. Both early and delayed uncoating have detrimental effects on viral infectivity. How uncoating relates to nuclear entry is currently hotly debated. Recent technological advances have led to intense discussions about the timing, location, and requirements for uncoating and have prompted the field to consider alternative uncoating scenarios that presently focus on uncoating at the nuclear pore and within the nuclear compartment. This review describes recent advances in the study of HIV-1 nuclear entry, outlines the interactions of the retroviral CA protein, and discusses the challenges of investigating HIV-1 uncoating.

scholarly journals Phenotypic Susceptibility to Bevirimat in Isolates from HIV-1-Infected Patients without Prior Exposure to Bevirimat

2010 ◽  
Vol 54 (6) ◽  
pp. 2345-2353 ◽  
Author(s):  
Nicolas A. Margot ◽  
Craig S. Gibbs ◽  
Michael D. Miller
Keyword(s):  
Recombinant Viruses ◽  
Gag Polyprotein ◽  
New Class ◽  
Major Mutation ◽  
Hiv Drugs ◽  
The Impact ◽  
First Time ◽  
Hiv 1

ABSTRACT Bevirimat (BVM) is the first of a new class of anti-HIV drugs with a novel mode of action known as maturation inhibitors. BVM inhibits the last cleavage of the Gag polyprotein by HIV-1 protease, leading to the accumulation of the p25 capsid-small peptide 1 (SP1) intermediate and resulting in noninfectious HIV-1 virions. Early clinical studies of BVM showed that over 50% of the patients treated with BVM did not respond to treatment. We investigated the impact of prior antiretroviral (ARV) treatment and/or natural genetic diversity on BVM susceptibility by conducting in vitro phenotypic analyses of viruses made from patient samples. We generated 31 recombinant viruses containing the entire gag and protease genes from 31 plasma samples from HIV-1-infected patients with (n = 21) or without (n = 10) prior ARV experience. We found that 58% of the patient isolates tested had a >10-fold reduced susceptibility to BVM, regardless of the patient's ARV experience or the level of isolate resistance to protease inhibitors. Analysis of mutants with site-directed mutations confirmed the role of the V370A SP1 polymorphism (SP1-V7A) in resistance to BVM. Furthermore, we demonstrated for the first time that a capsid polymorphism, V362I (CA protein-V230I), is also a major mutation conferring resistance to BVM. In contrast, none of the previously defined resistance-conferring mutations in Gag selected in vitro (H358Y, L363M, L363F, A364V, A366V, or A366T) were found to occur among the viruses that we analyzed. Our results should be helpful in the design of diagnostics for prediction of the potential benefit of BVM treatment in HIV-1-infected patients.

scholarly journals Human Mucosal Mast Cells Capture HIV-1 and Mediate Viraltrans-Infection of CD4+T Cells

2015 ◽  
Vol 90 (6) ◽  
pp. 2928-2937 ◽  
Author(s):  
Ai-Ping Jiang ◽  
Jin-Feng Jiang ◽  
Ji-Fu Wei ◽  
Ming-Gao Guo ◽  
Yan Qin ◽  
...  
Keyword(s):  
T Cells ◽  
Mast Cells ◽  
Cell Surface ◽  
Bacterial Infections ◽  
Mucosal Mast Cells ◽  
Mucosal Tissues ◽  
Viral Particles ◽  
Molecular Patterns ◽  
Hiv 1

ABSTRACTThe gastrointestinal mucosa is the primary site where human immunodeficiency virus type 1 (HIV-1) invades, amplifies, and becomes persistently established, and cell-to-cell transmission of HIV-1 plays a pivotal role in mucosal viral dissemination. Mast cells are widely distributed in the gastrointestinal tract and are early targets for invasive pathogens, and they have been shown to have increased density in the genital mucosa in HIV-infected women. Intestinal mast cells express numerous pathogen-associated molecular patterns (PAMPs) and have been shown to combat various viral, parasitic, and bacterial infections. However, the role of mast cells in HIV-1 infection is poorly defined. In this study, we investigated their potential contributions to HIV-1 transmission. Mast cells isolated from gut mucosal tissues were found to express a variety of HIV-1 attachment factors (HAFs), such as DC-SIGN, heparan sulfate proteoglycan (HSPG), and α4β7 integrin, which mediate capture of HIV-1 on the cell surface. Intriguingly, following coculture with CD4+T cells, mast cell surface-bound viruses were efficiently transferred to target T cells. Prior blocking with anti-HAF antibody or mannan before coculture impaired viraltrans-infection. Cell-cell conjunctions formed between mast cells and T cells, to which viral particles were recruited, and these were required for efficient cell-to-cell HIV-1 transmission. Our results reveal a potential function of gut mucosal mast cells in HIV-1 dissemination in tissues. Strategies aimed at preventing viral capture and transfer mediated by mast cells could be beneficial in combating primary HIV-1 infection.IMPORTANCEIn this study, we demonstrate the role of human mast cells isolated from mucosal tissues in mediating HIV-1trans-infection of CD4+T cells. This finding facilitates our understanding of HIV-1 mucosal infection and will benefit the development of strategies to combat primary HIV-1 dissemination.

Role of HIV-1-specific CD4 T cells

2006 ◽  
Vol 1 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Alexandre Harari ◽  
Cristina Cellerai ◽  
Giuseppe Pantaleo
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Hiv 1

scholarly journals HIV-specific T-cell Responses and Generalized Activation in HIV-1 Infected Long-term Non-progressors and Progressors from South India

2019 ◽  
Vol 16 (4) ◽  
pp. 302-314
Author(s):  
Chinnambedu Ravichandran Swathirajan ◽  
Ramachandran Vignesh ◽  
Greer Waldrop ◽  
Uma Shanmugasundaram ◽  
Pannerselvam Nandagopal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Activation Rates ◽  
Hiv 1

Background:Anti-viral cytokine expressions by cytotoxic T-cells and lower activation rates have been reported to correlate with suppressed HIV replication in long-term non-progressors (LTNP). Immune mechanisms underlying disease non-progression in LTNP might vary with HIV-1 subtype and geographical locations.Objective:This study evaluates cytokine expression and T-cells activation in relation to disease non-progression in LTNP.Methods:HIV-1 Subtype C infected LTNP (n=20) and progressors (n=15) were enrolled and flowcytometry assays were performed to study HIV-specific CD8 T-cells expressing IL-2, IFN-γ, TNF-α and MIP-1β against gag and env peptides. CD4+ T-cell activation was evaluated by surface expression of HLADR and CD38.Results:Proportions of cytokines studied did not differ significantly between LTNP and progressors, while contrasting correlations with disease progression markers were observed in LTNP. CD4+ T-cell activation rates were significantly lower in LTNP compared to progressors which indicate the potential role of T-cell activation rates in disease non-progression in LTNP.Conclusion:LTNP and progressors showed similar CD8+ T-cell responses, but final conclusions can be drawn only by comparing multiple immune factors in larger LTNP cohort with HIV-1 infected individuals at various levels of disease progression. A possible role of HIV-1 subtype variation and ethnic differences in addition to host-genetic and viral factors cannot be ruled out.

scholarly journals Role of Cell Surface Glycosaminoglycans of Human T Cells in Human Immunodeficiency Virus Type-1 (HIV-1) Infection

1996 ◽  
Vol 40 (11) ◽  
pp. 827-835 ◽  
Author(s):  
Yukako Ohshiro ◽  
Tsutomu Murakami ◽  
Kazuhiro Matsuda ◽  
Kiyoshi Nishioka ◽  
Keiichi Yoshida ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Human T Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

scholarly journals The critical role of human transcriptional repressor CTCF mRNA up-regulation in the induction of anti-HIV-1 responses in CD4+ T cells

2008 ◽  
Vol 117 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Yuchang Li ◽  
Guanhua Li ◽  
Anna Ivanova ◽  
Sagiv Aaron ◽  
Malgorzata Simm
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Critical Role ◽  
Transcriptional Repressor ◽  
Anti Hiv ◽  
Hiv 1

scholarly journals Characterization of Intact Proviruses in Blood and Lymph Node from HIV-Infected Individuals Undergoing Analytical Treatment Interruption

2019 ◽  
Vol 93 (8) ◽  
Author(s):  
Line K. Vibholm ◽  
Julio C. C. Lorenzi ◽  
Joy A. Pai ◽  
Yehuda Z. Cohen ◽  
Thiago Y. Oliveira ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Node ◽  
Treatment Interruption ◽  
Latent Reservoir ◽  
Lymphoid Tissues ◽  
Viral Rebound ◽  
Analytical Treatment ◽  
Latent Hiv ◽  
Hiv 1

ABSTRACT The role of lymphoid tissue as a potential source of HIV-1 rebound following interruption of antiretroviral therapy (ART) is uncertain. To address this issue, we compared the latent viruses obtained from CD4+ T cells in peripheral blood and lymph nodes to viruses emerging during treatment interruption. Latent viruses were characterized by sequencing near-full-length (NFL) proviral DNA and env from viral outgrowth assays (VOAs). Five HIV-1-infected individuals on ART were studied, four of whom participated in a clinical trial of a TLR9 agonist that included an analytical treatment interruption. We found that 98% of intact or replication-competent clonal sequences overlapped between blood and lymph node. In contrast, there was no overlap between 205 latent reservoir and 125 rebound sequences in the four individuals who underwent treatment interruption. However, rebound viruses could be accounted for by recombination. The data suggest that CD4+ T cells carrying latent viruses circulate between blood and lymphoid tissues in individuals on ART and support the idea that recombination may play a role in the emergence of rebound viremia. IMPORTANCE HIV-1 persists as a latent infection in CD4+ T cells that can be found in lymphoid tissues in infected individuals during ART. However, the importance of this tissue reservoir and its contribution to viral rebound upon ART interruption are not clear. In this study, we sought to compare latent HIV-1 from blood and lymph node CD4+ T cells from five HIV-1-infected individuals. Further, we analyzed the contribution of lymph node viruses to viral rebound. We observed that the frequencies of intact proviruses were the same in blood and lymph node. Moreover, expanded clones of T cells bearing identical proviruses were found in blood and lymph node. These latent reservoir sequences did not appear to be the direct origin of rebound virus. Instead, latent proviruses were found to contribute to the rebound compartment by recombination.

scholarly journals DC-SIGN–mediated Infectious Synapse Formation Enhances X4 HIV-1 Transmission from Dendritic Cells to T Cells

2004 ◽  
Vol 200 (10) ◽  
pp. 1279-1288 ◽  
Author(s):  
Jean-François Arrighi ◽  
Marjorie Pion ◽  
Eduardo Garcia ◽  
Jean-Michel Escola ◽  
Yvette van Kooyk ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cd4 T Cells ◽  
Synapse Formation ◽  
Model Systems ◽  
Hiv 1 ◽  
Infectious Synapse

Dendritic cells (DCs) are essential for the early events of human immunodeficiency virus (HIV) infection. Model systems of HIV sexual transmission have shown that DCs expressing the DC-specific C-type lectin DC-SIGN capture and internalize HIV at mucosal surfaces and efficiently transfer HIV to CD4+ T cells in lymph nodes, where viral replication occurs. Upon DC–T cell clustering, internalized HIV accumulates on the DC side at the contact zone (infectious synapse), between DCs and T cells, whereas HIV receptors and coreceptors are enriched on the T cell side. Viral concentration at the infectious synapse may explain, at least in part, why DC transmission of HIV to T cells is so efficient. Here, we have investigated the role of DC-SIGN on primary DCs in X4 HIV-1 capture and transmission using small interfering RNA–expressing lentiviral vectors to specifically knockdown DC-SIGN. We demonstrate that DC-SIGN− DCs internalize X4 HIV-1 as well as DC-SIGN+ DCs, although binding of virions is reduced. Strikingly, DC-SIGN knockdown in DCs selectively impairs infectious synapse formation between DCs and resting CD4+ T cells, but does not prevent the formation of DC–T cells conjugates. Our results demonstrate that DC-SIGN is required downstream from viral capture for the formation of the infectious synapse between DCs and T cells. These findings provide a novel explanation for the role of DC-SIGN in the transfer and enhancement of HIV infection from DCs to T cells, a crucial step for HIV transmission and pathogenesis.

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