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Track A – Basic Science Final Report . Giulia Marchetti Dept of Medicine, Surgery and Dentistry – Clinic of Infectious Diseases – University of Milan, San Paolo Hospital, Milan, Italy. PREVENTION. In the era of PrEP and treatment as prevention, do we still need vaccine? Vaccine is given once
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Track A – Basic ScienceFinal Report Giulia Marchetti Dept of Medicine, Surgery and Dentistry – Clinic of Infectious Diseases – University of Milan, San Paolo Hospital, Milan, Italy
PREVENTION • In the era of PrEP and treatment as prevention, do we still need vaccine? • Vaccine is given once • Durable protection • Cost-effectiveness G Nable, IAS 2011
Vaccine research • Gary Nable (USA)- The changing face of HIV vaccine research • development of resurfaced stabilized cores that can be used as probes for Human neutralizing antibodies and templates for immunogens • VRC01 Ab: neutralise 90% natural circulating viruses; determined the crystal structure of VRC01 in complex with a HIV-1 gp120 core; VRC01 partially mimics CD4 interaction with gp120 • A shift from the CD4-defined orientation, however, focuses VRC01 onto the vulnerable site of initial CD4 attachment, allowing it to overcome the glycan and conformational masking that diminishes the neutralization potency of most CD4-binding-site antibodies • maturation of VRC01 can now be reconstituted in laboratory settings- immunogen (vaccine research); passive transfer
Vaccine research • Barbara Ensoli (Italy) • vaccine involving a combination of HIV Tat and Env: efficacious in protecting macaques from mucosal SHIV challenge. • Susan Zolla-Pazner (USA) “Structural Vaccinology Approach” • cross-clade neutralizing antibodies using a gp120 DNA-based prime followed by a boost with a Env V3 attached to a Cholera Toxin B protein scaffold immunogen. • Susan Barnet (USA) • results from the RV144 trial and other studies utilizing non-human primates, which suggest that vaccine protection from HIV is an achievable goal. • identify a candidate that will provide this type of protection in humans. • David Weiner (USA) • “enhanced” DNA vaccine candidate: DNA containing consensus sequences of the target antigen combined with better delivery methods, such as tissue electroporation, and an IL-12 adjuvant - robust cell immune responses. • Felipe Garcia (USA) • dendritic cell based vaccine strategies. • HIV-specific responses and reduction in viral load in a limited number of individuals.
Time to consider a combination approach to biomedical interventions Robin Shattock (UK) • Mucosal exposure in the context of PrEP influence immune response (animal models) • VAXPrEP could deliver better protection by providing protection during immunization period, reducing infectious challenge, and increasing eclipse phase providing an extended opportunity for adaptive immunity to respond. • Vaccine candidates can be co-formulated with microbicides • Gp120 stable within genital gels • mucosal vaccination boost localized immunity
RESERVOIRS AND STRATEGIES TO ELIMINATE RESERVOIRS • CCR6: marker for memory T-cells imprinted with a transcriptional program favorable to HIV replication – LB Gosselin Canada • Lymph nodes reservoirs and alteration/dysregulation- LB J. Zaunders Australia; J Mudd USA • TH22 cells: gut HIV reservoir and immune activation on HAART – KIM (Canada)
GAMMA-CHAIN CYTOKINES – HAART INTENSIFICATION IL-7 & IL-15 - IL-7 resulted in higher proportion of proliferating Ki67+CD4+, but viral reactivation was increased only following IL-15 stimulation.Strategy to deplete the latent HIV reservoir -C. Vandergeeten RALTEGRAVIR INTENSIFICATION – In virologically suppressed patients on stable long-term HAART, intensification with raltegravir did not result in decay of HIV viral reservoirs in GALT CD4+ T-lymphocytes obtained from sigmoid colon biopsies at 48 weeks of follow up - J. Brunetta RAL intensification significantly accelerated the decay of latently infected CD4+ memory T cells, with no evidence of an effect on viral replication. - C. Gutiérrez
MECHANISMS OF DISEASE PROGRESSION • Naïve T cell recruitment is not the major source of CD4+ memory T cell production after infection; CD4+ memory T cells are intrinsically capable of self-renewal– LB A. OKOYE USA
Intestinal microbioma as driver of inflammation? • Greater representation of proinflammatory/inflammation-thriving class-level bacteria. Unique distributions of bacteria in samples from different anatomical sites which were not clearly impacted by HAART therapy – CL Ellis • Tryptophan catabolism as correlate of HIV disease progression and mortality? • Lower pretreatment tryptophan predict slower CD4+ recovery after 12 months therapy; lower pretreatment/month 6 tryptophan predict death, also adjusting for self-reported dietary protein intake – P Hunt
IMMUNE ACTIVATION/INFLAMMATION AND HIV DISEASEorWHAT DO WE KNOW (AND WHAT WE DO NOT KNOW) ON HOW HIV CAUSES AIDS?
The facts: • Immune activation predicts disease progression and response to HAART; • Immune activation persists on virologically-suppressive HAART; • Immune activation/inflammation on HAART associates to non-infectious complications • The questions: • What drives immune activation on HAART? • How can we target immune activation as an anti-HIV therapy?
Possible mechanisms behind elevated activation upon virologically-suppressive HAART– S. Deeks (USA) • Frequencies of PD-1+-expressing CD4+ T cells and cell-based measures of viral persistence were elevated in treated patients with low CD4+ T cell counts, suggesting that these individuals may be more difficult to cure and will require unique interventions- LB- Hatano, USA • Biomarkers of inflammation/coagulation: associations (and predictive role of) with • end-organ disease - J. Lundgren (Denmark); • metabolic complications - G. Behrens (Germany) • Hepatic flares in HIV/HCV and/ore HBV-co-infected patients after ART initiation are associated with high anti-inflammatory cytokine and HA (hyaluronic acid) levels; biomarkers indicative of inflammation and coagulation are associated with death – LB- I Sereti (USA)
HOW DO WE MOVE FORWARD? • MODELS OF PROTECTION • Non-pathogenicity of SIV-1 for African monkeys (get infected, present viremia, present immune activation only during acute infection) - M Mueller-Trutwin (France) • Elite controllers • VIRAL DETERMINANTS OF AIDS PATHOGENESIS • Which of the features that HIV genes acquired are critical for the immune activation and the infection outcome - F Kirchhoff (Germany) • INTERVENTIONAL TRIALS • “Interventional Trials targeting key pathways of “activation” can concurrently test hypotheses of pathogenesis and also explore promising treatment strategies for persons at risk for morbidity” – M Lederman (USA) – PANEL CONSENSUS • APPROACHES TO BLOCK INFLAMMATION/IMMUNE ACTIVATION–A Landay, P. Hunt (USA)
MODELS OF PROTECTION • Non-pathogenicity of SIV-1 for African monkeys (get infected, present viremia, present immune activation only during acute infection) - M Mueller-Trutwin (France) • Elite controllers • VIRAL DETERMINANTS OF AIDS PATHOGENESIS • Which of the features that HIV genes acquired are critical for the immune activation and the infection outcome - F Kirchhoff (Germany) • INTERVENTIONAL TRIALS • “Interventional Trials targeting key pathways of “activation” can concurrently test hypotheses of pathogenesis and also explore promising treatment strategies for persons at risk for morbidity” – M Lederman (USA) – PANEL CONSENSUS • APPROACHES TO BLOCK INFLAMMATION/IMMUNE ACTIVATION–A Landay, P. Hunt (USA)
MODELS OF PROTECTION- the monkey model Experimental depletion of CD25+CD4+ Treg (i.e. induction of immune activation ) in SIV-infected agm: delayed control of viral replication and of CD4+ T cell recovery despite no AIDS - I. Pandrea (USA) Reduced CCR5 expression on SM CD4+ TCM partially protects these cells from SIV infection, thus favoring CD4+ T-cell homeostasis – B Cervasi (USA) Alternative receptor usage in SM? – N.E. Riddick (USA) Maintenance of IL-21 producing CD4+ T-cells in SM? – M. Paiardini (USA) The ability of stimulated DN cells to produce Th1 and Th2 cytokines at levels comparable to CD4 cells indicates their potential to compensate for low CD4 levels in CD4-low SIV-infected SMs – D Sodora (USA)
MODELS OF PROTECTION- the “human model” Why do elite controllers have high T-cell activation but low HIV RNA? TNFα-skewed Gag and Nef specific CD8+ T cell profile and Microbial translocation in EC - M. Lopez (SPAIN); also S. DESAI (USA); ON THYMUS: XU YU (USA), ON FUNCTION: L.A. CHAKRABARTI (FRANCE) p21 acts as an intrinsic inhibitor of CDK9-mediated transcriptional elongation of HIV-1 in CD4 T cells from elite controllers-M. Lichterfeld (USA) REDUCED MACROPHAGE INFECTION: A. SAEZ-CIRION(FRANCE)
MODELS OF PROTECTION • Non-pathogenicity of SIV-1 for African monkeys (get infected, present viremia, present immune activation only during acute infection) - M Mueller-Trutwin (France) • Elite controllers • VIRAL DETERMINANTS OF AIDS PATHOGENESIS • Which of the features that HIV genes acquired are critical for the immune activation and the infection outcome - F Kirchhoff (Germany) • INTERVENTIONAL TRIALS • “Interventional Trials targeting key pathways of “activation” can concurrently test hypotheses of pathogenesis and also explore promising treatment strategies for persons at risk for morbidity” – M Lederman (USA) – PANEL CONSENSUS • APPROACHES TO BLOCK INFLAMMATION/IMMUNE ACTIVATION–A Landay, P. Hunt (USA)
High degree of HIV-1 group M genetic variability in North Angolan population, challenging diagnostic, treatment and prevention of HIV-1 in this low HIV/AIDS prevalence country - J.F. MACHADO DE MORAIS AFONSO (Brasil, Angola) • Attenuation of in vitro viral replication capacity in HIV-1 clade B subtype viruses circulating in Japan between 1993-2009 – S NOMURA (TOKYO) • Nef can inactivate ABCA1 by blocking the interaction between this cholesterol transporter and calnexin, the cellular endoplasmic reticulum chaperone involved in regulation of folding and maturation of glycosylated proteins - M. BUKRINSKY (USA)
MODELS OF PROTECTION • Non-pathogenicity of SIV-1 for African monkeys (get infected, present viremia, present immune activation only during acute infection) - M Mueller-Trutwin (France) • Elite controllers • VIRAL DETERMINANTS OF AIDS PATHOGENESIS • Which of the features that HIV genes acquired are critical for the immune activation and the infection outcome - F Kirchhoff (Germany) • INTERVENTIONAL TRIALS • “Interventional Trials targeting key pathways of “activation” can concurrently test hypotheses of pathogenesis and also explore promising treatment strategies for persons at risk for morbidity” – M Lederman (USA) – PANEL CONSENSUS • APPROACHES TO BLOCK INFLAMMATION/IMMUNE ACTIVATION–A Landay, P. Hunt (USA)
Chloroquine : Activation inhibitor • Statins/anti-IL-6: Inflammation inhibitors • Rifaxamin/Sevalamer: MT inhibitors • Multinational 4-week Phase IIa, double blinded, placebo controlled study OF AntiViral-HyperActivation Limiting Therapeutics (AV-HALT VS411), a novel fixed-dose combination of an antiviral and an antiproliferative drug: • Within 28 days treatment AV-HALTs decrease the degree of naïve cells proliferation allowing the replenishment of the naïve cells pool- LB - F. Lori (Italy)
Human stem cell-based gene therapy to engineer HIV-specific T-cell immunity can elicit functional anti-viral CTL in vivo S. KITCHEN (USA) • Non-human primate model of penile transmission (RM- SIVMAC251): SIV can be transmitted by penile SIV exposure but is ~50% less efficient than vaginal challenge B. KEELE (USA) • Genetic variations in Defensins and TLRs may affect host-virus interactions and impact the disease progression K. GIANESIN, ITALY
CRYPTOCOCCAL MENINGITIS: • Enhanced immunoregulatory/activated phenotype of CNS NK (chemoattraction via CXCL-10/CXCR3) - V. NARANBHAI (Durban- South Africa) • Enriched CD4/CD8 TEM CCR5 AND CXCR3-expressing in CSF , and CD4+ TEM in CSF in C-IRIS VS. NON-C-IRIS - C.C. CHANGM.A. FRENCH (Australia) • Placenta malaria associated with increased risk of MTCT of HIV-1 (aOR = 6.5; 1.4-30.9), especially among primigravidae (aOR = 12.0; 1.0-150; p< 0.05) - P. BULTERYS (USA/Rwanda) • GBV-C infection reduces B/NK activation and monocyte CCR5 surface expression -J.T. STAPLETON (USA) • Destruction of nervous cells is potentiated in the simultaneous presence of gp41 and Toxoplasma gondii- E.E. ESCOBAR GUEVARA (Venezuela)
1% Tenofovir gel (CAPRISA 004), has a direct anti-herpetic activity: • (i) it inhibits HSV-1 and HSV-2; • (ii) reduces HSV-1 and HSV-2 replication at different sites; • Topical drug administration appears to be a key requirement to enable this dual prophylactic effect of tenofovir - L. MARGOLIS (USA)
Leonid Margolis & Cristophe Vanpouille, USA Scott G Kitchen, USA A Special Thanks To: Camilla Tincati, Andrea Nannipieri Alessandra La Palombara and all the volunteers at the Rapporteur Office Valentina Svicher, Roma
THE ITALIAN GOVERNMENT STILL OWES 260 MILLION EUROS TO THE GLOBAL FUND AND NEVER PLEDGED FOR 2011 - 2013 ITALY:KEEP THE PROMISE, NOW!FUND THE FUND, NOW! AIDS, TUBERCOLOSIS AND MALARIA WILL NOT WAIT!