VGTI Florida A Systems Biology Approach to HIV Eradication and - - PowerPoint PPT Presentation

T R A N S L AT I N G R E S E A R C H I N T O H E A LT H

VGTI Florida A Systems Biology Approach to HIV Eradication and Control

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

VGTI Florida Translating Research Into Health

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

Systems Biology Approaches

• We know very little about
• The determinants and mechanisms of HIV disease progression, HIV

susceptibility and acquisition, HIV eradication

• We will measure all immune responses, we will avoid biases
• We will work mostly with human subjects by analysing the immune

response after perturbing the immune system by:

– An infection: why some control infections and others do not in subjects infected by different routes – Compare protective immunity induced by vaccines or other interventions and by natural protection – Why some licensed vaccines work in some and not in all – Test impact of routes of immunisation , age , gender and ethnic groups on response to vaccines and immune therapeutics – Adjuvants

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E Protective vaccine Natural infection In vivo models

Gene array qRT-PCR siRNA Functional protein validation In vivo validation

System Biology Platform to Identify Protective Immune Signatures

Bioinformatics

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

HIV Research Agenda at VGTI-FL

• Basic HIV Pathogenesis

– Mechanisms of HIV induced immune dysfunction in primary infection – Mechanisms of induced dysfunction – Mechanisms of HIV latency – Correlates of immune protection from disease progression – Correlates of immune protection from infection

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

HIV Research Agenda at VGTI-FL

• Translational Research

– Define Predictors of:

• Efficacy of interventions that are aimed at HIV acquisition and

prevention from HIV infection

• HIV disease evolution prior to and from earliest stages of HIV

infection ( Fiebeg I-II)

• Efficacy of immune interventions that are aimed, at

preventing HIV disease progression and in particular hyper immune activation, and at immune reconstitution

• Efficacy of immune and antiviral interventions that are aimed

at HIV eradication

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HIV Eradication It’s All About Synergy

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

THE HIV RESERVOIR

• The HIV Reservoir

– Where and how does HIV persists: role of hyperimmune activation – What triggers HIV latency :

• Role of negative regulators of T cell activation
• Role of myeloid : T cell interactions

– How do we eliminate latency and persistence – Immune reconstitution v/s eradication

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

Latency V/S Persistence

• Latent genomes: little if no viral replication in

slowly dividing homeostatically renewing cells

• Persistent genomes: low levels of viral

replication in myeloid cells; transmission to effector memory cells

Sorted PD-1high Cells Preferentially Harbor HIV-1 Integrated DNA When Compared to Their PD-1low Counterparts Hypothesis: PD-1 plays a role in the establishment of the HIV reservoir The establishment of a stable reservoir for HIV necessitates the establishment of viral latency = inhibition of viral production. Does PD-1 triggering inhibit viral production in HIV infected primary CD4+T cells?

PD-1 expression correlates with the reservoir size. Impact of PD-1 signaling on the maintenance and/or establishment of the HIV reservoir?

Integrated HIV DNA copies per 106 CD4 T cells % PD-1+ CD4 T cells 10 20 30 1 10 100 1000 10000  = 0.45 p = 0.01 100 200 300 400 500

Cm Tm Em PD-1Hi CD4 T cells PD-1Lo CD4 T cells HIV DNA copies per 106 cells Sorted PD-1 high cells are enriched in total and integrated HIV DNA compared to sorted PD-1 low cells : PD-1 high cells constitute a preferential reservoir for the virus.

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

Conclusions

• PD-1+ Central and Transitional memory CD4+T cells are enriched for HIV integrated DNA
• PD-1 receptor may be used as a specific marker to target HIV-1 reservoir cells
• PD-1 receptor triggering inhibits viral production. Role in the establishment of a reservoir?
• Blocking PD-1/PD-L1 interaction induces viral production. Role in the maintenance of a reservoir?

Can we purge the HIV reservoir by disrupting the PD-1 negative pathway in HAART individuals?

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CD4+ Central and Transitional Memory T Cells But Not CD4+ Naïve Cells Proliferate in Response to PD-1 Blockade

Time post PD-1 blockade (days)

CD4+ central memory CD4+ central memory CD4+ transitional memory CD4+ transitional memory CD4+ naive CD4+ naive

Δ %Ki67+ (change from baseline) Δ %Ki67+ (change from baseline) Δ %Ki67+ (change from baseline) Δ %Ki67+ (change from baseline) Δ %Ki67+ (change from baseline) Δ %Ki67+ (change from baseline)

Anti-PD1 (5mg/Kg) Anti-PD1 (5mg/Kg) Anti-PD1 (5mg/Kg) Anti-PD1 (5mg/Kg) Anti-PD1 (5mg/Kg) Anti-PD1 (5mg/Kg)

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

PD1 Blockade Leads to an Increase in SIV Specific CD8+ T Cell Responses in Blood

Anti-PD1 treated IgG control treated

CD8+ memory responses (%TNFα+ or IFNγ+) CD8+ memory responses (%TNFα+ or IFNγ+) CD8+ memory responses (%TNFα+ or IFNγ+)

Time post anti-PD1 administration (days)

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

Summary

• PD-1 is a master regulator of the immune

response

• It targets the earliest step of T cell activation
• It is critical for the establishment of the HIV

reservoir

• Intervention aimed at blocking PD-1 engagement

by its ligand can rescue T cell function .

• At least one trial will take place in the coming

year with anti-PD1

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

ARV CD4 T cells from virally suppressed subject RT-qPCR Stimulation HIV particles produced

Quantifying the Reservoir Reactivation Assay

The reactivation assay detects HIV particles that are produced by latently infected cells in the presence of ARVs.

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1 10 100 1000 10000

Duration of exposure to HIV > 1 year < 1 year Integrated HIV DNA copies per 106 CD4 T cells p < 0.0001 CD4/CD8 ratio

> 1 < 1 p < 0.0001

1 10 100 1000 10000

Integrated HIV DNA copies per 106 CD4 T cells

• Duration of Exposure to HIV (time before initiating HAART)
• CD4/CD8 ratio

Factors Impacting the Reservoir Size

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E

A Constellation of Therapies May Eradicate HIV

Vision

Those who are HIV+ would be started on:

• A HAART regimen of an

appropriate composition and at the earliest time

• One or more host modifiers,

e.g., SAHA, IL-15, and/or inhibitors of IL-7, chemokines, IDO, or MCSF

• Eliminate PD-1 TCM
• Virus would go away completely!

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A Systems Biology Approach to Define Mechanisms of Immune Dysfunction Induced by Cocaine and Other Substances of Abuse

V A C C I N E & G E N E T H E R A P Y I N S T I T U T E Cocaine blocks the reuptake of neurotransmitters such as dopamine and serotonin. Their increased extracellular concentrations modulate production of hormones essential for thymic activity. Cocaine can directly impact T cell homeostasis through opiate and sigma receptors present on immune cells leading to increased secretion of IL-10 and TFG-b (Zhu 2003).

How Can Cocaine Impact the Immune System?

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CD4 T cell counts in cocaine users, cocaine and marijuana users versus age-matched non-cocaine users CD4 T cells are significantly decreased in illicit drug users PART II. HIV+ treated cohort

ART+ coc+ ART+ coc+ mar+ ART+ non users

500 1000 1500

p=0.04 p=0.01 CD4 counts/ul

Impact of Cocaine Use on CD4 T Cell Counts in ART Treated Subjects

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ART+ cocaine+ ART+ non users

10 20 30 40

p=0.016 RTE T cell counts/ul

PART II. HIV+ treated cohort

ART+ cocaine+ ART+ non users 100 200 300 400

p=0.03 CD4 naive counts/ul

Naive and RTE cell counts in cocaine users (cocaine only or cocaine plus marijuana) versus age-matched non-cocaine users RTEs are the only subset significantly decreased in drug users Decreased CD4 T cells in drug users could be due to impaired thymic function

Impact of Cocaine Use on T Cell Homeostasis in ART Treated Subjects: Decreased Thymic Output?

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2D multidimensional scaling (MDS) revealed that cocaine users, cocaine and marijuana users and non users cluster into 3 distinct groups

Gene Array Profiling of Whole Blood From ART Treated HIV Infected Subjects

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Agenda

• Focus on performing proof of concept clinical trials aimed at

using drugs and biologics to answer specific questions of HIV pathogenesis and prevention in specific populations including

• lder subjects , hard to reach subjects ( drug abuse ) and very

early infection . Trials would be focused on:

• HIV eradication
• Immune dysfunction and hyper immune activation
• Immune reconstitution
• Develop of a cohort in very early infection : SEEK and TREAT
• Develop a pan Florida data base of subjects , samples and

tissues

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