bluuebunny/crossref_metadata_2025 huggingface dataset:
A-103 Combined immune-based strategies targeting viral persistence in ART-suppressed SIV-infected rhesus macaques
Authors: Paiardini Mirko
Published: April 2018

Antiretroviral therapy (ART) suppresses viral replication in HIV-infected individuals, but does not eliminate an extremely durable reservoir of latently infected cells that is established early after infection. Understanding the phenotype and location of latently infected cells represents a critical challenge in designing a cure for HIV; furthermore, many HIV-infected individuals given ART exhibit residual inflammation, which may contribute to virus persistence. This presentation will discuss immune based strategies targeting HIV persistence developed over the past several years using the model of SIV infection in rhesus macaques. Recent work identified PD-1+ follicular helper CD4+ T-cells as an important cellular compartment for viral persistence. We have described that CTLA-4+PD-1-memory CD4+ T-cells, which share phenotypic markers with regulatory T-cells and localize outside the B-cell follicle of the lymph nodes, are significantly enriched in SIV-DNA; contain robust levels of replication-competent virus; and increase their contribution to the SIV reservoir with prolonged ART. Finally, we showed that Interleukin-21 and IFN-alpha administration in ART-treated, SIV-infected RMs reduces residual immune activation during ART and temporally delay viral rebound after ART treatment interruption.

These recent advancements highlight the complexity and diversity of the mechanisms and T-cell populations that can contribute to the residual reservoirs of virally infected cells. Developing a range of different interventions to target individual components of viral reservoirs represent both a formidable challenge and an exciting opportunity for the years to come.
A-104 Immune Targeting of the Latent Reservoir
Authors: Nixon Douglas F.
Published: April 2018

HIV is a human infectious exogenous retrovirus which is thought to have infected human populations from cross primate species transmissions. Within our genomes are remnants of past infectious retroviruses which have endogenized, called “endogenous retroviruses” (ERVs). We have previously shown that human ERVs (HERVs) can be transcribed in an HIV infected cell, but had not identified which sub-family or unique HERV was transcribed. Using a novel computational pipeline, Telescope, we have identified which HERVs are expressed in HIV infected cells.

We have received funding for a Martin Delaney Collaboratory grant called “Believe” in which we research towards HIV eradication based upon enhanced targeted cell therapy. As part of this program, we have investigated whether we can identify markers which uniquely identify the latent reservoir. New data will be presented on 2 putative markers, CD32a and IFITM1.
B-101 Shooting many cytokines with a single Stone-a novel anti-cytokine technology with broad clinical application
Authors: Tagaya Yutaka , Zapata Juan , Wu Xiaorong , Basheer Asjad , Frohna Paul , Azimi Nazli
Published: April 2018

gc-cytokines (IL-2, -4, -7, -9, -15, -21) control major immune responses and lymphocyte development. Their aberrant production drives multiple human diseases including HTLV-1 associated myelopathy (HAM), T-cell malignancies, graft-versus-host (GvH) disease and autoimmunity (e.g., alopecia areata, Celiac disease, asthma). Importantly, these diseases are caused by 2 or more cytokines (multi-cytokine diseases) which cannot be effectively and safely treated by the current anti-cytokine approaches.

To address this issue, we developed a novel class of multi-cytokine inhibitors (MCI) that are designed as cytokine-mimetic peptides each of which contains a short motif shared by only the targeted cytokines of the γc family. Our first MCI, BNZ 132-1, selectively inhibits IL-2, -9, -15 without affecting other γc- or non-γc-cytokines. BNZ 132-1 efficiently eradicated LGL leukemic cells without damaging normal cells in the IL-15 leukemic model we developed, in which a Jak inhibitor (Tofacitinib) showed only limited efficacy (Nata et al 2015 J Biol Chem).

In humanized-mice infected with LCMV (a mouse model of cytokine release syndrome [CRS]), animals treated with BNZ 132-1 survived while all control animals died. BNZ 132-1 reversed the cytokine storm (IL-6, TNF-γ, IFN-γγ within 5 days, which is likely caused by the over-production of IL-2/IL-15). Similarly, GvH naturally occurring in humanized mice was effectively suppressed by the BNZ 132-1 treatment. These results suggest a potential application of BNZ 132-1 for GvH post transplantation and CRS post microbial infection, in addition to HAM and T-cell malignancies that we are targeting in our clinical trials. Thus, our new MCI technology fills in a major gap of anti-cytokine therapy.
P-A9 Transformation of Darunavir into a long acting nanoformulated prodrug
Authors: Banoub Mary , Bade Aditya , McMillan JoEllyn , Edagwa Benson , Gendelman Howard
Published: April 2018

Antiretroviral therapy (ART) has improved the quality and longevity of HIV-1 patients. Despite such advances limitations in drug bioavailability, resistance, and secondary toxicities abound affecting regimen adherence. We posit that such pharmaceutical limitations may be overcome by drug transformation into long acting slow effective release ART (LASER ART); a pharmaceutical approach that improves cell and tissue drug penetrance and depot formation leading to extended dosing intervals and improved antiretroviral responses. To this end, a hydrophobic bioreversible derivative prodrug of darunavir (DRV) was synthesized by medicinal chemistry. Modified DRV (MDRV) was synthesized by covalent linkage of a 14-carbon hydrophobic fatty acid moiety to the parent drug through a hemiaminal bond. A stable poloxamer 407 coated prodrug DRV nanoformulations (NMDRV) produced by high-pressure homogenization. Physicochemical properties of NMDRV and resultant particle cell uptake, antiretroviral efficacy pharmacokinetic and biodistribution studies were performed with subsequent comparisons made between prodrug and native drug formulations. Laboratory and pharmacokinetic tests were performed in monocyte derived macrophages (MDM) and BALB/c mice, respectively. NMDRV displayed up to 86 mg per 106 cells in 24 hours and retention up to 2 weeks compared to undetectable levels in the native DRV treatment. Effective plasma DRV concentration was detected in the prodrug arm through day 7 following a single dose of 40 mg/kg compared to undetectable levels in the parent drug treatment arm. The results highlight opportunities for LASER ART to achieve improved ART distribution and dissolution with limited toxicity for long-term HIV/AIDS treatments.
P-E4 The MoMent Study: Correlates of viral suppression at 6 months postpartum among HIV-positive women in rural Nigeria
Authors: Ramadhani Habib , Isah Christopher , Charurat Manhattan , Sam-Agudu Nadia
Published: April 2018

Introduction:

The risk of mother-to-child transmission of HIV (MTCT) reduces with sustained pre & postpartum administration of suppressive maternal ARVs. The MoMent study evaluated for maternal viral suppression & its correlates among HIV+ Nigerian women.

Methods:

This prospective cohort study compared structured Mentor Mother (MM) vs unstructured peer support (PS) for PMTCT outcomes. Pregnant women were recruited at 20 matched Primary Healthcare Centers in rural North-Central Nigeria. Structured PS included daily MM supervision, standardized documentation, client tracking, & MM performance evaluations. Maternal viral load (VL) was performed at 6 months postpartum; women lost to followup were tracked back for VL tests. Viral suppression was defined as VL <20 copies/mL. All participants were on ART for ≥6 months. Multivariate logistic regression with generalized estimating equations was used to account for clusters and for adjusting confounders.

Results:

Among 497 enrolees, 296 (59.6%) presented for VL; 273/296 (92.2%) had samples collected. Of the 238/273 (87.2%) with available results, 138 (58%) were suppressed. Correlates of suppression were structured MM support (aOR 4.9, CI 2.6 to 9.2); age >30 years (aOR 2.3, CI 1.0 to 4.9); ≥secondary education (aOR 2.0, CI 1.2 to 3.3); Christian religion (aOR 1.4, CI 1.1 to 2.1); PI-based ART (aOR 4.6, CI 1.3 to 16.0), and retention (aOR 3.7, CI 2.5 to 5.5). Marital/disclosure status & distance from facility were not significant.

Discussion:

Organized PS, older age, education, potent ARVs & retention supported viral suppression in our study. The role of religion is unclear & should be further explored.

Conclusion:

Structured PS should be targeted to young & lesser educated women to reduce MTCT risk.
P-G5 Differential immune response to HCV peptides as cancer-progression biomarkers of HCV-infections
Authors: Tornesello AnnaLucia , Reimer Ulf , Holenya Pavlo , Knaute Tobias , Tornesello MariaLina , Maria Buonaguro Franco
Published: April 2018

HCV infections are the main cause of chronic liver disease and in part of lymphoproliferative disorders. Most HCV infections (>90%) determine chronic hepatitis, 30% of which progress to liver cirrhosis and 3% annually to Hepatocellular Carcinoma (HCC). The progression rate is mainly articulated in low (>40 years) and high (<10 years) speed progressors, with the latter being associated to male gender, <40 years of age, >150mL daily alcohol consumption. Current progression markers are mainly based on biochemical evaluation of liver damage (elevation of alanine and aspartate transaminases) and inflammation (elevation of alpha-fetoprotein). Such markers are not specific and elevated also for other infections (ie, HBV and HCMV) or metabolic disorders (ie, steatosis). Specific HCV-related markers would be relevant to identify HCV co-factors and to select high priority people for direct anti-viral treatment.

To identify HCC progression markers, samples from HCV+ patients at different infection stage have been analyzed on the HCV-peptide platform newly developed by JPT Peptide Technologies GmbH (Germany). It covers the complete HCV-protein arrays with >3000 overlapping 15-amino-acid-long peptides from all structural and non structural HCV proteins. The currently available data (from 7 HCV+ asymptomatic, 5 HCV+ with cryoglobulinemia, 9 HCV cirrhosis/HCC and 5 HCV− patients) demonstrates that in asymptomatic patients the level of anti-HCV is in general very low (including anti-capsid/core proteins), while high levels of immunoresponse anti-non-structural proteins is present in patients with liver cancer. Confirmation of such data would support the anti-non structural response as biomarker of cancer progression in HCV+ patients.
P-A10 Accumulation and persistence of deleted HIV proviruses following prolonged ART
Authors: Anderson Elizabeth , Hill Shawn , Bell Jennifer , Simonetti Francesco , Rehm Catherine , Jones Sara , Gorelick Rob , Kearney Mary
Published: April 2018

HIV-1 immunotherapy offers an alternative to cART or as a “functional cure” by eliminating reactivated viral reservoirs. Both cellular and antibody mediated immune responses have been identified which are capable of reducing either HIV-1 infection risk or severity of infection. We present data on both T-cell based (Vacc4x) and antibody based (vacc-C5) vaccine antigen under development for HIV-1 immunotherapy. Vacc4x has undergone phase II trials demonstrating reductions in viral load and sustained anti-HIV-1 T-cell responses. Additional immune modulation, such as that used in cancer immunotherapy, may have utility in HIV-1 Immunotherapy. For this reason we combined Vacc4x with the immune modulator Lenalidomide both in vitro and in a phase I trial of 24 subjects in order to assess the ability of this combination to enhance CD4+ T cell responses. The combination was safe, well tolerated and demonstrated increases in CD4+ T-cell counts after a 2 week vaccine protocol. We have identified that antibodies specific for a heterodimeric peptide construct comprising the C5501-512 and gp41732-744 regions of the HIV envelope protein (Vacc-C5) are correlated with slow disease progression, lower viral load and markers of immune function in HIV-1 patients and are capable of mediating antibody dependent cytotoxicity. We conducted a phase I/II trial of 36 ART treated patients vaccinated with Vacc-C5 antigen. Vacc-C5 was safe, well tolerated and increased anti-Vacc-C5 titre in a subset of patients. These data support the continued development of Vacc4x, Lenalidomide and Vacc-C5 in an HIV-1 immunotherapeutic setting.
P-C1 Development of HIV-1 Immunotherapy with Vacc4x and Vacc-C5
Authors: Smith Peter , Sommerfelt Maja , Stjernholm Grete , Ökvist Mats , Zeldis Jerome , Sorenson Birger , Kvale Dag , Dalgleish Angus
Published: April 2018

HIV-1 immunotherapy offers an alternative to cART or as a “functional cure” by eliminating reactivated viral reservoirs. Both cellular and antibody mediated immune responses have been identified which are capable of reducing either HIV-1 infection risk or severity of infection. We present data on both T-cell based (Vacc4x) and antibody based (vacc-C5) vaccine antigen under development for HIV-1 immunotherapy.

Vacc4x has undergone phase II trials demonstrating reductions in viral load and sustained anti-HIV-1 T-cell responses. Additional immune modulation, such as that used in cancer immunotherapy, may have utility in HIV-1 Immunotherapy. For this reason we combined Vacc4x with the immune modulator Lenalidomide both in vitro and in a phase I trial of 24 subjects in order to assess the ability of this combination to enhance CD4+ T cell responses. The combination was safe, well tolerated and demonstrated increases in CD4+ T-cell counts after a 2 week vaccine protocol.

We have identified that antibodies specific for a heterodimeric peptide construct comprising the C5501-512 and gp41732-744 regions of the HIV envelope protein (Vacc-C5) are correlated with slow disease progression, lower viral load and markers of immune function in HIV-1 patients and are capable of mediating antibody dependent cytotoxicity. We conducted a phase I/II trial of 36 ART treated patients vaccinated with Vacc-C5 antigen. Vacc-C5 was safe, well tolerated and increased anti-Vacc-C5 titre in a subset of patients.

These data support the continued development of Vacc4x, Lenalidomide and Vacc-C5 in an HIV-1 immunotherapeutic setting.
P-E1 A novel way to test and discover new inhibitors against drug resistant HIV-1 proteases
Authors: Li Ge , Ferrer Marc , Zhao Richard
Published: April 2018

HIV-1 protease (PR) inhibitor (PI) is one of the most potent anti-HIV drugs. When it is used in combination with other drugs, if could suppress HIV to an undetectable level. However, successful treatment is often threaten by emergence of viral drug resistance of PRs (vdrPRs). Three vdrPRs were isolated from HIV-infected patients that carry 7 (M7PR), 10 (M10PR) and 11 (M11PR) PR gene mutations, respectively. They were expressed in a gene-inducible fission yeast system to allow the measurement of PR-specific activities. All 3 vdrPRs proteolyzed natural HIV viral substrates and conferred drug resistance to Indinavir in the fission yeast, suggesting they maintained the same proteolytic and drug resistant activities in the fission yeast as in mammalian cells. Moreover, the viral enzymatic activities of these vdrPRs coupled with the induction of growth inhibition and cell death, which could potentially be used as endpoints to test the efficacy of PI activities. In this study, 5 investigational PIs were used to test the utility of the PR-producing yeast system with Darunavir (DRV) as a control. All 6 compounds suppressed the wildtype PR and the M7PR-mediated activities. However, none of them suppressed activities conferred by M10PR or M11PR. The fact that M10PR and M11PR were resistant to all of the existing PI drugs including DRV, underscores the importance of continued searching for new PIs against vdrPRs. The described fission yeast cell-based system might be suitable for future testing or discovery of new PIs through high-throughput drug screening. Because this yeast cell-based method is function-driven. It has no presumption of what kind of PI will be found. It has the potential to uncover novel PIs.
B-106 Development of anti-tumor cytotoxic lymphocytes using engineered human primary blood dendritic cells
Authors: Wu Long , Zhang Huan , Jiang Yixing , Gallo Robert , Cheng Hua
Published: April 2018

Dendritic cell (DC)-based immunotherapy has achieved modest clinical benefits, however, several technical hurdles in DC preparation, activation and cancer-associated antigen (TAA) delivery limit its broad applications in cancer therapy. We have developed immortalized and activated human primary blood dendritic cell (DC) lines, ihv-DCs. Human primary blood dendritic cells can be immortalized from several cc of peripheral blood and can be expanded at large quantity at normal cell culture condition. The ihv-DCs are a subset of CD11c+/CD205+ DCs that persistently display co-stimulatory molecules and produce interferon gamma. These DCs are engineered to constitutively express a TAA such as hTERT, which prime donor-derived T cells to generate antigen-specific CTLs that induce cytolysis of hTERT-expressing target cells in an HLA-A2-restricted manner. In addition, the engineered DCs are able to induce simultaneous production of both anti-cancer CTLs and NK cells from naive PBMCs. In NSG mouse model, infusion of the activated CTLs and NK cells that are generated from naive PBMCs using the engineered DCs suppress lung metastasis of human lung cancer cells. Both CTLs and NK cells are found to infiltrate lung as well as lymphoid tissues, mimicking the in vivo trafficking patterns of cytotoxic lymphocytes. This new approach should facilitate the development of cell-based immunotherapy for human lung cancer.
C-105 Quaternary Configuration of the HIV-1 Receptor-Binding Site
Authors: Lusso Paulo , Liu Qingbo , Acharya Priyamvada , Dolan Michael , Zhang Peng , Guzzo Christina , Lu Jacky , Kwon Alice , Gururani Deepali
Published: April 2018

The native trimeric HIV-1 envelope (Env) spike displayed on the surface of mature virions is the sole functional form that mediates viral attachment and entry. Interaction of conserved elements in the external envelope glycoprotein, gp120, with the CD4 receptor is the first critical step in the HIV-1 infectious cycle. Although the CD4-binding site in gp120 has been extensively characterized by mutagenesis and co-crystallization with soluble CD4, most of these studies were performed on monomeric gp120 subunits, precluding the recognition of potential quaternary-specific components. Here, we show that the functional HIV-1 Env trimer interacts with CD4 through a quaternary surface formed by coalescence of the previously defined CD4-contact region in the gp120 outer domain with a second binding site (CD4-BS2) in the inner domain of a neighboring gp120 protomer. Disruption of CD4-BS2 in diverse HIV-1 Envs reduces the stability of CD4-trimer interaction and abrogates HIV-1 infectivity by preventing the acquisition of coreceptor-binding competence. A corresponding reduction in HIV-1 infectivity occurs upon mutation of CD4 residues that interact with CD4-BS2. A 6.8-Å cryoEM structure of a stabilized trimer (DS-SOSIP) in complex with soluble CD4 confirmed the quaternary contact. Selected neutralizing human antibodies also recognize a quaternary surface that spans CD4-BS2, providing evidence that this region is immunogenic in vivo. These results document the quaternary configuration of the functional HIV-1 receptor-binding site, with implications for treatment and vaccine design.
D-102 Immune-based interventions for HIV cure: lessons from NHP models
Authors: Silvestri Guido
Published: April 2018

While the availability of potent anti-retroviral therapy, ART, has dramatically reduced the mortality and morbidity associated with HIV infection, no intervention that can functionally “cure” the infection is yet available. This is due to a persistent reservoir of latently infected cells that is resistant to both ART (which targets specific phases of the “productive” virus life cycle) and immune-based interventions (which require expression of viral proteins as target antigens). Over the past few years, the non-human primate model of SIV/SHIV infection of rhesus macaques has been developed and validated for studies of HIV eradication in the setting of fully suppressive ART. In this presentation, I will review: (i) the opportunities presented by the SIV/SHIV macaque models to conduct studies aimed at developing and testing novel interventions to achieve a functional cure for HIV infection; (ii) the main immune-based strategies that are currently explored to reduce or eliminate the virus reservoir in the NHP model (i.e., shock & kill, block & lock; soothe & schmooze; push & vanish; as well as transplant and gene therapy); and (iii) the published and ongoing preclinical trials of immune-based interventions that are conducted by our team in ART-treated SIV-infected rhesus macaques with the goal of inducing a functional cure. Among the used interventions I will discuss type I interferons, interleukin-21, FTY720, check-point blockade inhibition (i.e., inhibitors of PD-1, CTLA4, and LAG-3), CD8+ T cell depletion, CD4+ T cell depletion, and autologous stem cell transplantation.
D-105 Reversible HIV-1 Latency Induced in Primary Human Monocyte-Derived Macrophages by Repeated M1 Polarization
Authors: Graziano Francesca , Aimola Giulia , Forlani Greta , Turrini Filippo , Accolla Roberto , Vicenzi Elisa , Poli Guido
Published: April 2018

The contribution of tissue-associated macrophages to the viral reservoir in HIV-1 infected individuals receiving cART remains highly debated. In this regard, we have previously reported that functional M1 polarization of primary human MDM by short-term (18 h) stimulation with pro-inflammatory cytokines (IFN-γ plus TNF-α) leads to a significant containment of virus replication. Here, we demonstrate that restimulation of infected M1-MDM with the same pro-inflammatory cytokines 7 days after infection (M12 MDM) leads to a superior containment of virus replication to near undetectable levels, as determined by RT activity released in culture supernatants, in comparison to both control (CTR) MDM and to M1-MDM that were not restimulated by polarizing cytokines. M12 MDM showed an upregulation of APOBEC3A and 3G, with a significant reduction of HIV DNA and virtual lack of viral mRNA expression together with the expression of transcriptional inhibitors of proviral gene expression, namely CIITA and TRIM22, although expression and phosphorylation of transcriptional inducers of HIV-1 provirus, such as NF-kB and STAT-1, were not impaired. Latently infected M12-MDM harbored replication-competent virus that was promptly reactivated by allogeneic PHA blasts or their culture supernatant. Thus, our study provides a formal demonstration that a state of reversible latent HIV-1 infection can be established in primary human MDM upon their repeated M1 polarization by stimulation with pro-inflammatory cytokines before and after in vitro infection leading to a dominance of restrictive over permissive factors.
D-108 Innate-primed alternative signaling pathways enhance functional mucosal mobilization of memory-like NK cells in HIV/SIV infection
Authors: Reeves Keith
Published: April 2018

Burgeoning evidence indicates a broader functional repertoire for NK cells beyond innate immunity including adaptive functions. Specifically, memory-like NK cells lacking the FcR γ-signaling chain (FcRΔg-NK cells) still require antibody to grant antigen-specificity, but are pre-sensitized for rapid mobilization against viral antigens. Interestingly, FcRΔg-NK cells require innate priming by CMV, but execute memory-like killing against HIV and SIV through poorly understood mechanisms.

Sixty rhCMV−, rhCMV+, and chronically SIV-infected macaques were studied and compared to thirty naive and untreated HIV-infected humans. FcRΔg-NK cells were systemically distributed but, correlating with viral load, increased four-fold in CMV+ and HIV/SIV-subjects, including in the GI tract. Upregulated CD16 and α4β7 suggested memory-like priming is required for both antibody-dependent functions and mucosal homing. FcRΔg-NK cells exhibited two-fold more robust IFN-γ secretion and cytotoxicity in the presence of antibody, but reduced expression of Helios and Eomes—indicative of epigenetic modifications, and clustered independently from traditional NK cells in multidimensional t-SNE. The γ-chain adaptor, Syk was absent or dephosphorylated in FcRΔg-NK cells, but ζ-chain, phosphorylated by adaptor Zap70, was significantly upregulated, indicating use of the alternative ζ-chain/Zap70 pathway to achieve greater functional potency.

Our work presents the first description of a combinatorial mechanism of innate-priming and alternative signaling to explain the memory-like phenomena of NK cells mobilized against HIV/SIV. Future studies harnessing memory-like NK cells could create exciting modalities for both vaccine and curative therapies.
D-109 Defining a potent new class of latency reversing agents devoid of toxicity and detrimental cell activation that enhance CTL/NK cell killing
Authors: Gramatica Andrea , Schwarzer Roland , Montano Mauricio , Herzig Eytan , Packard Thomas , Greene Warner C.
Published: April 2018

Despite long-term administration of antiretroviral therapy (ART), HIV-1 persists in a broadly distributed latent reservoir mainly comprised of resting CD4+ T cells. Cells harboring latent provirus typically display little to no HIV-1 gene expression and thus remain invisible to the immune system. To achieve a durable sustained viral remission in HIV-infected patients off ART (a functional cure), it will be important to both “reduce the size of the reservoir and to control viral rebound by eliciting an effective immune response capable of restraining viral spread from the smaller reservoir. This approach will likely require the combined use of potent and safe latency-reversing agent (LRA) and a therapeutic HIV vaccine.

Our recent studies have shown that activators of the AKT/mTOR pathway form a promising group of LRAs. Our interest has focused on two small molecules, SB-216763 and Tideglusib that commonly inhibit glycogen synthase kinase-3 (GSK-3). This inhibition triggers a metabolic shift to glycolysis and results in sequential activation of mTORC2, AKT, and mTORC1. Both compounds are known to have high tissue penetration including the brain.

We found that these GSK-3 inhibitors potently activate latent HIV-1 in both a tissue-based model of HIV latency formed in primary CD4 T cells, and in CD4 T cells isolated from HIV-infected patients. In some experiments, these agents are more potent than anti-CD3/anti-CD28 antibodies even though the GSK-3 inhibitors do not appear to induce T cell activation (measured by changes in CD69 and CD25 expression). Finally, in contrast to the undesirable compromise of CTL/NK function associated with many first generation LRAs (PKC activators, HDAC inhibitors), the GSK-3 inhibitors actually enhance CTL and NK cell effector function.

In summary, our findings reveal GSK-3 inhibitors as an interesting new class of potent, safe, non-cell activating LRAs. Next, it will be key to define their activity in vivo using SIV-infected macaques on suppressive ART. The fact that tideglusib is already in phase II human trials for myotonic dystrophy and autism could accelerate its ultimate testing as an LRA in HIV-infected patients.
F-102 Inflammation and immune modulation: tackling age-related stem cell dysfunction
Authors: Jasper Heinrich
Published: April 2018

In aging and diseased tissues, regeneration and regenerative therapies are limited by stem cell dysfunction and unfavorable tissue environments. Promising strategies to improve success include interventions that enhance stem cell function and that harness and boost endogenous tissue repair mechanisms. We study stem cells and tissue repair in barrier epithelia and the retina of Drosophila and mice to explore the causes and consequences of age-related regenerative dysfunction. These studies have led to the discovery of interventions targeting age-related inflammation, stem cell proliferation, stem cell metabolism, innate immune responses, and the commensal microbiota as strategies to enhance regeneration and extend lifespan. I will discuss these strategies and provide perspectives for the development of targeted interventions to improve tissue function in the elderly. I will highlight strategies to improve stem cell activity by targeting endogenous proliferation, differentiation and nutrient response pathways, and strategies to improve tissue repair by modulating innate immunity and host/commensal interactions. Combining such strategies is likely to significantly improve tissue homeostasis and regenerative therapies in the elderly, ultimately extending the healthy years of life.
F-103 Targeting aberrant transcription in pre-cancerous stem cells
Authors: Steidl Ulrich G.
Published: April 2018

Relapse continues to be the most common cause of death in acute myeloid leukemia (AML) and many other cancers. Recent evidence has shown that the accumulation of stepwise genetic and epigenetic changes in tissue-specific stem cells lead to the formation of pre-cancerous/pre-leukemic stem cells (pre-LSC) that play a pivotal role not only in disease origination but also in relapse. While the existence and essentiality of such pre-cancerous cell states has been demonstrated in mice and humans, still very little is known about the molecular mechanisms driving pre-LSC formation and progression. We have recently performed molecular studies of pre-leukemic cell states in mouse genetic models as well as primary cells from patients, and discovered new transcription factors and regulatory mechanisms in pre-LSC in myelodysplastic syndromes (MDS) and AML. We have uncovered critical roles for several transcription factors in pre-LSC, and found that enhancer haplodeficiency and resulting minimal reduction of key transcription factors can be sufficient to induce pre-LSC formation and subsequent progression to MDS and AML. Such models provide novel tools for mechanistic study of pre-LSC and their progression to overt MDS and AML, and for the development and testing of pharmacological approaches to therapeutically interfere with these processes.

In summary, recent studies have started to shed light on pre-cancerous stem cell states as the earliest origin of various malignancies including MDS and AML, as well as molecular mechanisms driving their formation and progression. These advances provide a basis for the specific therapeutic targeting of pre-cancerous stem cells for the causative treatment of MDS and AML and other cancers.
G-101 Human papillomaviruses and carcinogenesis: well-established and novel models
Authors: Tommasino Massimo
Published: April 2018

Human papillomaviruses (HPVs) infect the cutaneous or mucosal epithelia. More than 200 HPV types have been isolated so far, and they are classified phylogenetically as genera and species. Persistent infections by the mucosal high-risk (HR) HPV types from genus alpha have been clearly associated with cancer development of the genital and upper respiratory tracts. The products of two early genes, E6 and E7, are the major HR HPV oncoproteins, being essential in all steps of the carcinogenic process. They exert their functions by interacting with a large number of cellular proteins, including the products of tumour suppressor genes, and altering their properties. Biological and epidemiological data indicate that beta HPV types, together with ultraviolet (UV) radiation, promote non-melanoma skin cancer development. However, in contrast to the HR mucosal HPV types, cutaneous beta HPV types appear to be required only at an early stage of carcinogenesis, facilitating the accumulation of UV-induced DNA mutations. Several findings also suggest that these HPV types and other carcinogens may synergize in the induction of malignancies at different anatomical sites.
H-102 The detente between herpes simplex viruses and their human host
Authors: Roizman Bernard
Published: April 2018

The key mission of viruses is to spread within its ecological niche. To achieve their mission viruses must multiply efficiently, be available at appropriate body sites for transmission and yet not kill the host since extreme virulence that kills the host curtails the spread of viruses in a population as illustrated by SARS and Ebola viruses. HSV infects a very large fraction of human population and is therefore a successful pathogen. To achieve it mission the virus encodes functions of omission that fail to block host immune responses and functions of commission that specifically curtail its replication. The net effect is the evolution of a pathogen that controls its replication so as to maintain a high level of contacts between infected and uninfected individuals.
H-103 Towards a universal influenza virus vaccine
Authors: Palese Peter
Published: April 2018

Despite FDA-approved vaccines and antivirals, seasonal and pandemic influenza remains a serious threat associated with substantial morbidity and mortality. While annual seasonal influenza virus vaccination is frequently effective–albeit underutilized in most countries–a safe universal influenza virus vaccine providing broad and long-lasting immunity would represent a major breakthrough. We have developed vaccine constructs which express chimeric hemagglutinins resulting in the redirection of the immune response away from the immunodominant (variant) head domain of the hemagglutinin toward the much more conserved stalk of the hemagglutinin and the highly conserved neuraminidase. Such vaccine constructs work well in animal challenge models and await extensive clinical trials in humans. The mechanism by which these novel vaccines mediate protection is via antibodies which do not rely on hemagglutination inhibitory (HI) activity but rather on ADCC (antibody-dependent cell-mediated cytotoxicity) effects, activation of complement and/or inhibition of virus replication through directly binding to viral proteins. It is hoped that the universal influenza virus vaccine based on chimeric hemagglutinins will provide long-lasting protection against all seasonal and pandemic influenza virus strains in the future with the possibility of eventually eliminating influenza B.
I-101 The changing natural history of HIV infection: From opportunistic infections to inflammation and chronic diseases
Authors: Masur Henry
Published: April 2018

Clinicians are well aware of the changing natural history of HIV infection in regions where antiretroviral therapy is accessible. Clinical investigations of HIV in the first 20 years of the epidemic focused on the diagnosis, treatment and prevention of opportunistic infections. While there has always been a need to improve management strategies, effective approaches were developed for most opportunistic infections, although the quality and duration of survival were short until antiretroviral therapy became effective and durable. As patients have live longer, morbidity due to comorbidities related to viral diseases (HCV, HBV, HPV, CMV), metabolic disorders, chronic inflammation, and neoplastic processes have become more prevalent. Health care systems have had to augment and expand their screening programs for such morbidities, and develop more comprehensive health care for HIV infected patients who survive with these co morbidities. Washington, D.C. is an example of a city which is realigning its resources to focus on these emerging comorbidities and to integrate care. Data on these comorbidities provide insight into research challenges that must be met.
I-103 The metabolic complications of HIV
Authors: Peters Barry
Published: April 2018

Some conditions of metabolic origin are, at least in part, considered to be associated or driven by HIV infection or its treatment. These include hyperlipidaemia, lipodystrophy, type 2 diabetes, non-alcoholic fatty liver disease (non-ALFLD), fragility fractures, and some elements of cardiovascular disease.

There are several behavioural factors, particularly diet exercise, alcohol, smoking, and there are some antiretroviral drugs, that contribute to the high incidence of metabolic disease in people living with HIV (PLWH). Some fundamental biological and cellular mechanisms may be important in driving metabolic abnormalities in PLWH. Irisin, a cleaved part of a protein encoded by the FNDC5 (Fibronectin type III domain-containing protein 5) gene, has been correlated in PLWH with adiposity, and inversely correlated with fat free mass and some strength parameters. HIV may disrupt fundamental metabolic host cell processes and further enable a preferential environment for virion assembly. The metabolic syndrome and obesity appear to be key for many cases of liver fibrosis in PLWH with concomitant hepatitis virus infection. The METAFIB study found that adipokines and SCD163 (a soluble form of Cluster of Differentiation receptor163), were significantly associated with fibrosis of the liver.

To improve metabolic health outcomes in PLWH, we need further studies to increase our evidence base and develop better therapies. Therapeutic strategies include the identification of risk factors for metabolic disease in PLWH, such as fatty liver, and screening for diabetes, affording the opportunity to encourage behavioural change such as diet and exercise, and the selection of appropriate antiretroviral medication.
I-108 Assessing the contribution of myeloid cells to HIV-1 persistence under ART
Authors: Stevenson Mario , Machado Viviane
Published: April 2018

Assessing whether myeloid cells support HIV-1 persistence in the face of effective ART represents a significant technical challenge. As a result, there is as yet, no direct evidence that myeloid cells play any role in viral persistence in ART-suppressed individuals. As a consequence, research on myeloid cell reservoirs is falling into obscurity. Infection of macrophages can only be initiated by HIV-1 variants that have the ability to use low levels of CD4 on the cell surface. Therefore, if a functional myeloid reservoir contributes to viral persistence under effective ART, we would predict that viremia that rebounds following analytic treatment interruption (ATI), would contain viral variants that have a high affinity for CD4. We have developed an approach that allows identification of low frequency macrophage-tropic variants in rebounding viremia post ATI. Through single genome amplification (SGA), we cloned a large number of viral envelopes from plasma of individuals who underwent ATI. Furthermore, we have assessed whether macrophage-tropic viruses contributed to viral rebound in individuals who exhibited prolonged remission after receiving reduced intensity bone marrow transplant When these envelopes were used to construct recombinant molecular clones, they conferred the ability to fuse with, and replicate within primary macrophages. We believe that these results provide strong evidence for the existence of a myeloid cell reservoir in infected individuals on suppressive ART and furthermore, that this reservoir contributes to viral rebound when ART is interrupted. The longevity and the anatomic source of the reservoir from which these macrophage-tropic viruses originate, is under investigation.
J-101 Current challenges in HIV diagnostics–Time to revise our approach?
Authors: Peel Sheila A.
Published: April 2018

HIV infection remains a public health challenge; HIV testing serving as the gateway to entrance into the HIV care, treatment, and prevention cascade. Whether laboratory evidence of infection is generated by Point of Care test algorithms or highly sophisticated 4th and 5th generation immunoassay/supplemental serological and/or molecular confirmatory algorithms, diagnostic accuracy, correct classification of HIV infection status, is now challenged by the HIV field's most notable advances in the arenas of HIV Prevention and Intervention. Paradigms such as Test and Treat, Treatment as Prevention, Pre-exposure Prophylaxis (PrEP), and Post-exposure Prophylaxis (PEP) reduce viral burden, viral reservoir constitution, the potential for onward HIV transmission, and decrease the risk of serious AIDS related health outcomes. These highly effective strategies however, have also been shown to cause the delay, reduction, or reversal of evolution of serological responses to infection and/or reduce molecular markers to below limits of detection by currently employed assay. Lack of evolution and/or suppression of markers long used by the laboratory to generate evidence confirming or refuting HIV infection can thus lead to misclassification of status. This talk will focus on current HIV testing modalities, challenges of HIV testing under the aforementioned scenarios, presentation of case studies, and considerations for a revised approach.
J-104 Geenius HIV 1/2 Supplemental Assay: A Rapid, Reliable and Simple System for the Confirmation and Differentiation of Antibodies to HIV
Authors: Shriver Kathleen , Cardona Muriel , Gadelle Stephane , Sarfati Patrice
Published: April 2018

INTRODUCTION:

In 2017 Bio-Rad Laboratories completed launching the FDA-approved Geenius HIV-1/HIV-2 Supplemental assay to replace Multispot HIV-1/HIV-2 in the current CDC HIV Diagnostic Algorithm. The Geenius cassette contains antibody-binding protein A, which is conjugated to colloidal gold dye particles; HIV-1 (p31, gp160, p24, gp41) and HIV-2 (gp36, gp140) antigens are bound to the membrane solid phase. Serum, plasma, or whole blood may be tested. Geenius uses an automated cassette reader and proprietary software to interpret HIV-1 and HIV-2 results. We report more recent performance data for this system, as well as an investigational protocol for testing dried blood spot (DBS) specimens.

METHODS:

(1) WHO evaluated the Geenius HIV-1/HIV-2 Supplemental testing system with a panel of 1117 specimens. (2) DBS specimens were tested on Geenius using an investigational procedure (40 μL of DBS eluate and one drop of assay buffer). Samples included established infections (131 HIV-1, 31 HIV-2, one dual), 60 seroconversion specimens, and 106 DBS collected by CDC during HIV surveillance.

RESULTS:

(1) Geenius sensitivity in the WHO evaluation was 100% and specificity was 97.4%. Seroconversion samples were detected +0.875 days vs. the benchmark. All the mixed titer and reference specimens were correctly classified. (2) Geenius DBS correctly detected HIV-1 and HIV-2 DBS with minor exceptions. DBS seroconversions showed slightly reduced sensitivity vs. plasma.

CONCLUSIONS:

(1) The Geenius HIV-1/2 Confirmatory Assay was accepted for the WHO list of prequalified diagnostics (March 17, 2017). (2) Results of an investigational Geenius DBS procedure appear promising for settings without capacity for venipuncture.
J-105 Recent developments in HIV testing in the US: Where we are, what's new, and where we hope to go
Authors: Delaney Kevin
Published: April 2018

In the last 30+ years, there have been significant advances in the field of HIV testing. Improvements in test sensitivity for early or acute HIV infection have occurred largely because test developers have targeted analytes that appear sooner after infection. But there have also been advances in other aspects of the tests, including things like reductions in the time to it takes for tests to produce a result in the laboratory, and tests that can be performed accurately outside of laboratory settings (e.g. in a park, nightclub, or a church). While the performance of individual tests improved incrementally over the last 30 years, from 1989 until 2014 the algorithm for laboratory diagnosis of HIV infection remained largely unchanged. But, since 2014, that guidance has already been updated twice as new data and new tests continue to emerge. However, challenges have also been identified as laboratories try to implement the recommended algorithm. In addition to logistical issues with the algorithm, recent data have documented how PrEP and early treatment initiation have led to new questions for HIV diagnostics. In the face of these challenges, the landscape of available HIV tests continues to expand and improve. Several groups are developing platforms for single use devices that quantify HIV nucleic acid in less than an hour. In fact, similar technologies have already been implemented for other viral diseases. This presentation will review the latest information on HIV test technologies, describe the challenges and opportunities that current and emerging technologies create for HIV testing, and discuss barriers to implementation and new opportunities for HIV prevention and care in the context of this evolving technology.
P-A1 CBF-1 promotes the establishment and maintenance of HIV latency by recruiting Polycomb repressive complexes, PRC1 and PRC2, at HIV LTR
Authors: Tyagi Mudit , Zicari Sonia , Farley Kalamo , Sun Lin , Simon Gary
Published: April 2018

The type of chromatin structure around the LTR promoter of integrated HIV provirus provides critical signals that regulate transcription during both productive and latent HIV infections. The C-promoter binding factor-1 (CBF-1) is a potent and specific inhibitor of the HIV-1 transcription, which perform its function after binding to specific sites at HIV LTR. Here we demonstrate that the knockdown of endogenous CBF-1 in latently infected primary CD4+ T cells, using specific small hairpin RNAs (shRNA), resulted in the reactivation of latent HIV proviruses. By performing Chromatin immunoprecipitation (ChIP) assays, using latently infected primary T cells and Jurkat T-cell lines, we demonstrated that CBF-1 induces the establishment and maintenance of HIV latency by recruiting Polycomb Group (PcG/PRC) corepressor complexes or Polycomb repressive complexes 1 and 2 (PRC1 and PRC2). Knockdown of CBF-1 resulted in the dissociation of PRCs corepressor complexes and enhanced the recruitment of RNA polymerase II (RNAPII) at HIV LTR. Knockdown of certain components of PRC1 and PRC2 leads to the reactivation of latent proviruses. Similarly, treatment of latently infected primary CD4+ T cells with the EZH2 inhibitor, 3-deazaneplanocin A (DZNep), led to their reactivation.

Importance:

Instead of inhibiting individual enzymes, targeting factors such as CBF-1, which mediate the establishment of multiple repressive epigenetic changes, could be more beneficial in designing strategies to reactivate and subsequently eliminate latent HIV reservoirs.
P-A2 Development of anti-Tat compound: MD Simulation of the Tat/Cyclin T1/CDK9 Complex Revealing the Hidden Catalytic Cavity within the CDK9 Molecule Upon Tat Binding
Authors: Okamoto Takashi , Asamitsu Kaori , Hirokawa Takatsugu
Published: April 2018

We applied molecular dynamics (MD) simulation to analyze the dynamic behavior of the Tat/CycT1/CDK9 tri-molecular complex and revealed the structural changes of P-TEFb upon Tat binding. We found that Tat could deliberately change the local flexibility of CycT1. Although the structural coordinates of the H1 and H2 helices did not substantially change, H1', H2', and H3' exhibited significant changes en masse. Consequently, the CycT1 residues involved in Tat binding, namely Tat-recognition residues (TRRs), lost their flexibility with the addition of Tat to P-TEFb. In addition, we clarified the structural variation of CDK9 in complex with CycT1 in the presence or absence of Tat. Interestingly, Tat addition significantly reduced the structural variability of the T-loop, thus consolidating the structural integrity of P-TEFb. Finally, we deciphered the formation of the hidden catalytic cavity of CDK9 upon Tat binding. MD simulation revealed that the PITALRE signature sequence of CDK9 flips the inactive kinase cavity of CDK9 into the active form by connecting with Thr186, which is crucial for its activity, thus presumably recruiting the substrate peptide such as the C-terminal domain of RNA pol II. These findings provide vital information for the development of effective novel anti-HIV drugs with CDK9 catalytiactivity as the target.