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

VGTI Florida A Systems Biology Approach to HIV Eradication and Control 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 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

System Biology Platform to Identify Protective Immune Signatures Gene In vivo array validation Bioinformatics Protective vaccine Natural infection In vivo qRT-PCR models siRNA Functional protein validation 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 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 Eradication It ’ s All About Synergy 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

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 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

Sorted PD-1 high Cells Preferentially Harbor HIV-1 Integrated DNA When Compared to Their PD-1 low Counterparts 10000 Integrated HIV DNA copies per HIV DNA copies per 10 6 cells 500 1000 PD-1 Hi CD4 T cells 10 6 CD4 T cells 400 PD-1 Lo CD4 T cells 100 300 200 10  = 0.45 p = 0.01 100 1 0 Cm Tm Em 0 10 20 30 % PD-1+ CD4 T cells Sorted PD-1 high cells are enriched in PD-1 expression correlates with the total and integrated HIV DNA compared to reservoir size. sorted PD-1 low cells : PD-1 high cells Impact of PD-1 signaling on the constitute a preferential reservoir for the maintenance and/or establishment of the virus. HIV reservoir? 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?

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? 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

CD4+ Central and Transitional Memory T Cells But Not CD4+ Naïve Cells Proliferate in Response to PD-1 Blockade CD4+ central memory CD4+ transitional memory CD4+ naive Anti-PD1 Anti-PD1 Anti-PD1 (5mg/Kg) (5mg/Kg) (5mg/Kg) (change from baseline) (change from baseline) (change from baseline) Δ %Ki67+ Δ %Ki67+ Δ %Ki67+ CD4+ central memory CD4+ transitional memory CD4+ naive Anti-PD1 Anti-PD1 Anti-PD1 (5mg/Kg) (5mg/Kg) (5mg/Kg) (change from baseline) (change from baseline) (change from baseline) Δ %Ki67+ Δ %Ki67+ Δ %Ki67+ Time post PD-1 blockade (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

PD1 Blockade Leads to an Increase in SIV Specific CD8+ T Cell Responses in Blood Anti-PD1 treated CD8+ memory responses CD8+ memory responses (%TNFα + or IFNγ + ) (%TNFα + or IFNγ + ) CD8+ memory responses (%TNFα + or IFNγ + ) IgG control treated 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

Quantifying the Reservoir Reactivation Assay Stimulation ARV HIV particles produced RT-qPCR CD4 T cells from virally suppressed subject The reactivation assay detects HIV particles that are produced by latently infected cells in the presence of ARVs. 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

Factors Impacting the Reservoir Size Integrated HIV DNA copies p < 0.0001 10000 Integrated HIV DNA copies p < 0.0001 per 10 6 CD4 T cells 10000 per 10 6 CD4 T cells 1000 1000 100 100 10 10 1 1 < 1 year > 1 year < 1 > 1 CD4/CD8 ratio Duration of exposure to HIV • Duration of Exposure to HIV (time before initiating HAART) • CD4/CD8 ratio 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! 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 Systems Biology Approach to Define Mechanisms of Immune Dysfunction Induced by Cocaine and Other Substances of Abuse 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

How Can Cocaine Impact the Immune System? 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). 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

Impact of Cocaine Use on CD4 T Cell Counts in ART Treated Subjects PART II. HIV+ treated cohort p=0.04 p=0.01 1500 CD4 counts/ul 1000 500 0 ART+ coc+ ART+ coc+ mar+ ART+ non users 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 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

Impact of Cocaine Use on T Cell Homeostasis in ART Treated Subjects: Decreased Thymic Output? PART II. HIV+ treated cohort p=0.03 p=0.016 40 400 RTE T cell counts/ul CD4 naive counts/ul 30 300 20 200 10 100 0 0 ART+ cocaine+ ART+ non users ART+ cocaine+ ART+ non users 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 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

Gene Array Profiling of Whole Blood From ART Treated HIV Infected Subjects 2D multidimensional scaling (MDS) revealed that cocaine users, cocaine and marijuana users and non users cluster into 3 distinct groups 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