Engineered Bacteriophage T4 Nanoparticle as a Potential Targeted Activator of HIV-1 Latency in CD4+ Human T cells

The latent HIV-1 reservoir containing stably integrated and transcriptionally silent proviruses in CD4+ T cells is a major barrier for virus eradication. Targeted reactivation of the latent reservoir remains a major challenge in establishing a path for an HIV-1 cure. Here, we investigated the possibility of reactivating the HIV-1 reservoir by targeting engineered bacteriophage T4 capsid nanoparticles to reservoir cells. The surface lattice of the 120 x 86 nm phage capsid was arrayed with CD4 binding ligands such as recombinant CD4DARPin or the HIV-1 gp140 envelope protein. When exposed to either PBMCs or the resting CD4+ T cells in vitro, these nanoparticles caused T cells activation without inducing global T cell activation. Furthermore, the nanoparticles reactivated HIV-1 proviral transcription that led to virus assembly and release in the J-Lat cells, a cell line model of HIV-1 latency. Intriguingly, the observed T cell activation and HIV-1 latency reversal did not occur through the classic PKC or NFAT pathways suggesting the involvement of a yet unknown pathway. These studies demonstrate that engineered non-infectious bacteriophages could be potentially exploited for HIV-1 cure and other targeted T cell therapies.

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Inconsistent Reversal of HIV-1 Latency Ex Vivo by Antigens of HIV-1, CMV, and Other Infectious Agents

10.21203/rs.3.rs-35386/v1 ◽

2020 ◽

Author(s):

Thomas Vollbrecht ◽

Aaron O. Angerstein ◽

Bryson Menke ◽

Nikesh M. Kumar ◽

Michelli Faria Oliveira ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Ex Vivo ◽

Latent Reservoir ◽

Antigen Specificity ◽

Pcr Assay ◽

Hiv 1

Abstract BackgroundA reservoir of replication-competent but latent virus is the main obstacle to a cure for HIV-infection. Much of this reservoir resides in memory CD4 T cells. We hypothesized that these cells can be reactivated with antigens from HIV and other common pathogens to reverse latency. ResultsWe obtained mononuclear cells from the peripheral blood of antiretroviral-treated patients with suppressed viremia. We tested pools of peptides and proteins derived from HIV and from other pathogens including CMV for their ability to reverse latency ex vivo by activation of memory responses. We assessed activation of the CD4 T cells by measuring the up-regulation of cell-surface CD69. We assessed HIV-expression using two assays: a real-time PCR assay for virion-associated viral RNA and a droplet digital PCR assay for cell-associated, multiply spliced viral mRNA. Reversal of latency occurred in a minority of cells from some participants, but no single antigen induced HIV-expression ex vivo consistently. When reversal of latency was induced by a specific peptide pool or protein, the extent was proportionally greater than that of T cell activation. ConclusionsIn this group of patients in whom antiretroviral therapy was started during chronic infection, the latent reservoir does not appear to consistently reside in CD4 T cells of a predominant antigen-specificity. Peptide-antigens reversed HIV-latency ex vivo with modest and variable activity. When latency was reversed by specific peptides or proteins, it was proportionally greater than the extent of T cell activation, suggesting partial enrichment of the latent reservoir in cells of specific antigen-reactivity.

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CCR7 ligands CCL19 and CCL21 increase permissiveness of resting memory CD4+ T cells to HIV-1 infection: a novel model of HIV-1 latency

Blood ◽

10.1182/blood-2007-06-097907 ◽

2007 ◽

Vol 110 (13) ◽

pp. 4161-4164 ◽

Cited By ~ 162

Author(s):

Suha Saleh ◽

Ajantha Solomon ◽

Fiona Wightman ◽

Miranda Xhilaga ◽

Paul U. Cameron ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Lymphocyte Migration ◽

Major Barrier ◽

Memory Cd4 T Cells ◽

Novel Model ◽

Hiv 1

Latent HIV-1 infection of resting memory CD4+ T cells represents the major barrier to HIV-1 eradication. To determine whether the CCR7 ligands involved in lymphocyte migration can alter HIV-1 infection of resting CD4+ T cells, we infected purified resting CD4+ T cells after incubation with the chemokines CCL19 and CCL21. Incubation with CCL19 or CCL21 did not alter markers of T-cell activation or proliferation. However, after HIV-1 infection of CCL19- or CCL21-treated CD4+ T-cells, we observed low-level HIV-1 production but high concentrations of integrated HIV-1 DNA, approaching that seen in mitogen-stimulated T-cell blasts. Restimulation of CCL19-treated infected CD4+ T cells resulted in virus production consistent with establishment of postintegration latency. CCR7 ligands facilitate efficient entry of HIV-1 into resting CD4+ T cells. These studies demonstrate a unique action of the chemokines CCL19 and CCL21 and provide a novel model with which to study HIV-1 latency in vitro.

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Inconsistent reversal of HIV-1 latency ex vivo by antigens of HIV-1, CMV, and other infectious agents

10.21203/rs.3.rs-35386/v2 ◽

2020 ◽

Author(s):

Thomas Vollbrecht ◽

Aaron O. Angerstein ◽

Bryson Menke ◽

Nikesh M. Kumar ◽

Michelli Faria Oliveira ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Ex Vivo ◽

Latent Reservoir ◽

Antigen Specificity ◽

Pcr Assay ◽

Hiv 1

Abstract BackgroundA reservoir of replication-competent but latent virus is the main obstacle to a cure for HIV-1 infection. Much of this reservoir resides in memory CD4 T cells. We hypothesized that these cells can be reactivated with antigens from HIV-1 and other common pathogens to reverse latency. ResultsWe obtained mononuclear cells from the peripheral blood of antiretroviral-treated patients with suppressed viremia. We tested pools of peptides and proteins derived from HIV-1 and from other pathogens including CMV for their ability to reverse latency ex vivo by activation of memory responses. We assessed activation of the CD4 T cells by measuring the up-regulation of cell-surface CD69. We assessed HIV-1 expression using two assays: a real-time PCR assay for virion-associated viral RNA and a droplet digital PCR assay for cell-associated, multiply spliced viral mRNA. Reversal of latency occurred in a minority of cells from some participants, but no single antigen induced HIV-1 expression ex vivo consistently. When reversal of latency was induced by a specific peptide pool or protein, the extent was proportionally greater than that of T cell activation. ConclusionsIn this group of patients in whom antiretroviral therapy was started during chronic infection, the latent reservoir does not appear to consistently reside in CD4 T cells of a predominant antigen-specificity. Peptide-antigens reversed HIV-1 latency ex vivo with modest and variable activity. When latency was reversed by specific peptides or proteins, it was proportionally greater than the extent of T cell activation, suggesting partial enrichment of the latent reservoir in cells of specific antigen-reactivity.

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Inconsistent reversal of HIV-1 latency ex vivo by antigens of HIV-1, CMV, and other infectious agents

Retrovirology ◽

10.1186/s12977-020-00545-x ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Thomas Vollbrecht ◽

Aaron O. Angerstein ◽

Bryson Menke ◽

Nikesh M. Kumar ◽

Michelli Faria de Oliveira ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Ex Vivo ◽

Latent Reservoir ◽

Antigen Specificity ◽

Pcr Assay ◽

Hiv 1

Abstract Background A reservoir of replication-competent but latent virus is the main obstacle to a cure for HIV-1 infection. Much of this reservoir resides in memory CD4 T cells. We hypothesized that these cells can be reactivated with antigens from HIV-1 and other common pathogens to reverse latency. Results We obtained mononuclear cells from the peripheral blood of antiretroviral-treated patients with suppressed viremia. We tested pools of peptides and proteins derived from HIV-1 and from other pathogens including CMV for their ability to reverse latency ex vivo by activation of memory responses. We assessed activation of the CD4 T cells by measuring the up-regulation of cell-surface CD69. We assessed HIV-1 expression using two assays: a real-time PCR assay for virion-associated viral RNA and a droplet digital PCR assay for cell-associated, multiply spliced viral mRNA. Reversal of latency occurred in a minority of cells from some participants, but no single antigen induced HIV-1 expression ex vivo consistently. When reversal of latency was induced by a specific peptide pool or protein, the extent was proportionally greater than that of T cell activation. Conclusions In this group of patients in whom antiretroviral therapy was started during chronic infection, the latent reservoir does not appear to consistently reside in CD4 T cells of a predominant antigen-specificity. Peptide-antigens reversed HIV-1 latency ex vivo with modest and variable activity. When latency was reversed by specific peptides or proteins, it was proportionally greater than the extent of T cell activation, suggesting partial enrichment of the latent reservoir in cells of specific antigen-reactivity.

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Costimulation of T-cell activation and virus production by B7 antigen on activated CD4+ T cells from human immunodeficiency virus type 1-infected donors

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.90.23.11094 ◽

1993 ◽

Vol 90 (23) ◽

pp. 11094-11098 ◽

Cited By ~ 30

Author(s):

O K Haffar ◽

M D Smithgall ◽

J Bradshaw ◽

B Brady ◽

N K Damle ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Immunodeficiency Virus ◽

T Cell Lines ◽

Antigen Presenting ◽

Hiv 1

Infection with the human immunodeficiency virus type 1 (HIV-1) requires T-cell activation. Recent studies have shown that interactions of the T-lymphocyte receptors CD28 and CTLA-4 with their counter receptor, B7, on antigen-presenting cells are required for optimal T-cell activation. Here we show that HIV-1 infection is associated with decreased expression of CD28 and increased expression of B7 on CD4+ T-cell lines generated from seropositive donors by alloantigen stimulation. Loss of CD28 expression was not seen on CD4+ T-cell lines from seronegative donors, but up-regulation of B7 expression was observed upon more prolonged culture. Both T-cell proliferation and interleukin 2 mRNA accumulation in HIV-1-infected cultures required costimulation with exogenous B7 because these events were blocked by CTLA4Ig, a soluble form of CTLA-4 that binds B7 with high avidity. In contrast, levels of HIV-1 RNA were not affected by CTLA4Ig, indicating that regulation of virus transcription in these cultures did not depend upon CD28-B7 engagement. Infected T cells could present alloantigen to fresh, uninfected CD4+ T cells, leading to increased proliferation and virus spread to the activated cells. Both of these events were blocked by CTLA4Ig. Thus, chronic activation of HIV-1-infected CD4+ T cells reduces expression of CD28 and increases expression of B7, thereby enabling these T cells to become antigen-presenting cells for uninfected CD4+ T cells; this might be another mechanism for HIV-1 transmission via T-cell-T-cell contact.

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HIV-1 Nef Enhances Dendritic Cell-Mediated Viral Transmission to CD4+ T Cells and Promotes T-Cell Activation

PLoS ONE ◽

10.1371/journal.pone.0034521 ◽

2012 ◽

Vol 7 (3) ◽

pp. e34521 ◽

Cited By ~ 19

Author(s):

Corine St. Gelais ◽

Christopher M. Coleman ◽

Jian-Hua Wang ◽

Li Wu

Keyword(s):

T Cells ◽

T Cell ◽

Dendritic Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Viral Transmission ◽

Hiv 1

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FOXP3 expressing CD127lo CD4+ T cells inversely correlate with CD38+ CD8+ T cell activation levels in primary HIV-1 infection

Journal of Leukocyte Biology ◽

10.1189/jlb.0507281 ◽

2007 ◽

Vol 83 (2) ◽

pp. 254-262 ◽

Cited By ~ 64

Author(s):

Lishomwa C. Ndhlovu ◽

Christopher P. Loo ◽

Gerald Spotts ◽

Douglas F. Nixon ◽

Frederick M. Hecht

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Cd8 T Cell ◽

Hiv 1

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Low SAMHD1 expression following T-cell activation and proliferation renders CD4+ T cells susceptible to HIV-1

AIDS ◽

10.1097/qad.0000000000000594 ◽

2015 ◽

pp. 1 ◽

Cited By ~ 15

Author(s):

Nicolas Ruffin ◽

Vedran Brezar ◽

Diana Ayinde ◽

Cécile Lefebvre ◽

Julian Schulze Zur Wiesch ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Samhd1 Expression ◽

Hiv 1

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A subgroup of Ugandan elite and viremic controllers naturally control HIV-1 infection by blocking R5-tropic viral entry.

10.21203/rs.3.rs-86395/v1 ◽

2020 ◽

Author(s):

Alex Kayongo ◽

Derrick Semugenze ◽

Mary Nantongo ◽

Fred Semitala ◽

Anxious Jackson Niwaha ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Viral Entry ◽

Peripheral Blood ◽

Cd4 T Cells ◽

Cell Activation ◽

Cd4 T Cell ◽

Controlled Study ◽

Hiv 1

Abstract Background: World over, there are antiretroviral therapy naïve individuals infected with HIV who maintain their CD4+T cell count above 500 cells/µl over 7-10 years and viral loads well controlled below undetectable levels (termed elite controllers, ECs) or at least 2,000 copies/mL (termed viremic controllers, VCs) for at least 12 months. Mechanisms responsible for HIV control in these individuals have not been fully elucidated. We hypothesized that CD4+T cells from elite and viremic controllers are naturally resistant to HIV-1 infection by blocking R5-tropic viral entry. We conducted a case-controlled study in which archived peripheral blood from 31 ECs/VCs and 15 progressors were investigated using in vitro HIV-1 infectivity assays. Results: Briefly, we purified CD4+T cells from peripheral blood using EasySep CD4+ positive selection kit followed by CD4+T cell activation using IL-2, anti-CD28 and anti-CD3. Three days post-activation, CD4+T cells were spinoculated and co-cultured with vesicular stomatitis virus G (VSV-G)-pseudotyped HIV, R5 (ADA-enveloped)- and X4 (NL4.3-enveloped v)-tropic HIV-1. Three days post infection, we quantified and compared the percentage infection of CD4+T cells in cases and controls. We demonstrate that a subgroup of Ugandan elite and viremic controllers possess CD4+T cells that are specifically resistant to R5-tropic virus, remaining fully susceptible to X4-tropic virus. Conclusion: Our study suggests that a subgroup of Ugandan elite and viremic controllers naturally control HIV-1 infection by blocking R5-tropic viral entry. Further research is needed to explore mechanisms of HIV control in the African population.

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