Treatment with indinavir, zidovudine, and lamivudine in adults with human immunodeficiency virus infection and prior antiretroviral therapy

Evolution of Intravitreal Therapy for Retinal Diseases-From CMV to CNV: The LXXIV Edward Jackson Memorial Lecture

PURPOSE

To present the evolution of intravitreal therapy for retinal diseases and its impact on clinical practice.

DESIGN

Retrospective literature review and personal perspective.

METHODS

Retrospective literature review and personal perspective.

RESULTS

Pharmacotherapeutic advances in retinal disease have been remarkable over the last 25 years. Almost all of the new drugs developed have required intravitreal administration to be highly effective, leading to an exponential increase in the annual number of intravitreal injections given. The use of intravitreal antibiotic injections to treat endophthalmitis, usually on a one-time basis, first familiarized ophthalmologists with this method of drug delivery. Ganciclovir was the first widely available, relatively inexpensive compounded drug that was used for repeat intravitreal injection to treat a chronic retinal disease, followed by triamcinolone for diabetic macular edema and bevacizumab for neovascular age-related macular degeneration. Ganciclovir was formulated for sustained-release drug delivery to avoid frequent intravitreal injections, a goal that has been more elusive for anti-VEGF drugs. Political obstacles encountered while conducting some of the trials to evaluate these treatments were substantial. Addressing the issues they raised led to important national policy changes that will impact the conduct of future clinical trials. The first comparative efficacy trial of intravitreal therapies was the Comparison of AMD Treatments Trials (CATT). The primary results from CATT and the many publications that followed continue to shape the use of intravitreal therapy today.

CONCLUSION

Intravitreal therapy has proven highly effective for the treatment of many retinal diseases. The treatment burden for patients from numerous injections, the cost to health care systems, and the impact on workflows in clinical practice have been substantial. Efforts to develop effective intravitreal therapies with reduced treatment burden and cost are ongoing.

Cell Death Pathways in Mutant Rhodopsin Rat Models Identifies Genotype-Specific Targets Controlling Retinal Degeneration

Retinitis pigmentosa (RP) is a group of inherited neurological disorders characterized by rod photoreceptor cell death, followed by secondary cone cell death leading to progressive blindness. Currently, there are no viable treatment options for RP. Due to incomplete knowledge of the molecular signaling pathways associated with RP pathogenesis, designing therapeutic strategies remains a challenge. In particular, preventing secondary cone photoreceptor cell loss is a key goal in designing potential therapies. In this study, we identified the main drivers of rod cell death and secondary cone loss in the transgenic S334ter rhodopsin rat model, tested the efficacy of specific cell death inhibitors on retinal function, and compared the effect of combining drugs to target multiple pathways in the S334ter and P23H rhodopsin rat models. The primary driver of early rod cell death in the S334ter model was a caspase-dependent process, whereas cone cell death occurred though RIP3-dependent necroptosis. In comparison, rod cell death in the P23H model was via necroptotic signaling, whereas cone cell loss occurred through inflammasome activation. Combination therapy of four drugs worked better than the individual drugs in the P23H model but not in the S334ter model. These differences imply that treatment modalities need to be tailored for each genotype. Taken together, our data demonstrate that rationally designed genotype-specific drug combinations will be an important requisite to effectively target primary rod cell loss and more importantly secondary cone survival.

Reasons and predictors for antiretroviral therapy change among HIV-infected adults at South West Ethiopia

OBJECTIVE

This retrospective cohort study is aimed to assess reasons and predictors of regimen change from initial highly active antiretroviral therapy among 1533 Human Immunodeficiency virus-infected adult patients at the Jimma University Tertiary Hospital.

RESULTS

One in two (47.7%) adults changed their antiretroviral therapy regimen. Patients who were above the primary level of education [Hazard ratio (HR) 1.241 (95% CI 1.070-1.440)] and with human immunodeficiency virus/tuberculosis co-infection [HR 1.405 (95% CI 1.156-1.708)] had the higher risk of regimen change than their comparator. Individuals on Efavirenz [HR 0.675 (95% CI 0.553-0.825)] and non-stavudine [HR 0.494 (95% CI 0.406-0.601)] based regimens had lower risk of regimen change.

Characterization of designed, synthetically accessible bryostatin analog HIV latency reversing agents

HIV latency in resting CD4+ T cell represents a key barrier preventing cure of the infection with antiretroviral drugs alone. Latency reversing agents (LRAs) can activate HIV expression in latently infected cells, potentially leading to their elimination through virus-mediated cytopathic effects, host immune responses, and/or therapeutic strategies targeting cells actively expressing virus. We have recently described several structurally simplified analogs of the PKC modulator LRA bryostatin (termed bryologs) designed to improve synthetic accessibility, tolerability in vivo, and efficacy in inducing HIV latency reversal. Here we report the comparative performance of lead bryologs, including their effects in reducing cell surface expression of HIV entry receptors, inducing proinflammatory cytokines, inhibiting short-term HIV replication, and synergizing with histone deacetylase inhibitors to reverse HIV latency. These data provide unique insights into structure-function relationships between A- and B-ring bryolog modifications and activities in primary cells, and suggest that bryologs represent promising leads for preclinical advancement.

Trends in HIV Terminology: Text Mining and Data Visualization Assessment of International AIDS Conference Abstracts Over 25 Years

Background

The language encompassing health conditions can also influence behaviors that affect health outcomes. Few published quantitative studies have been conducted that evaluate HIV-related terminology changes over time. To expand this research, this study included an analysis of a dataset of abstracts presented at the International AIDS Conference (IAC) from 1989 to 2014. These abstracts reflect the global response to HIV over 25 years. Two powerful methodologies were used to evaluate the dataset: text mining to convert the unstructured information into structured data for analysis and data visualization to represent the data visually to assess trends.

Objective

The purpose of this project was to evaluate the evolving use of HIV-related language in abstracts presented at the IAC from 1989 to 2014.

Methods

Over 80,000 abstracts were obtained from the International AIDS Society and imported into a Microsoft SQL Server database for data processing and text mining analyses. A text mining module within the KNIME Analytics Platform, an open source software, was then used to mine the partially processed data to create a terminology corpus of key HIV terms. Subject matter experts grouped the terms into categories. Tableau, a data visualization software, was used to visualize the frequency metrics associated with the terms as line graphs and word clouds. The visualized dashboards were reviewed to discern changes in terminology use across IAC years.

Results

The major findings identify trends in HIV-related terminology over 25 years. The term “AIDS epidemic” was dominantly used from 1989 to 1991 and then declined in use. In contrast, use of the term “HIV epidemic” increased through 2014. Beginning in the mid-1990s, the term “treatment experienced” appeared with increasing frequency in the abstracts. Use of terms identifying individuals as “carriers or victims” of HIV rarely appeared after 2008. Use of the terms “HIV positive” and “HIV infected” peaked in the early-1990s and then declined in use. The terms “men who have sex with men” and “MSM” were rarely used until 1994; subsequently, use of these terms increased through 2014. The term “sex worker” steadily increased in frequency throughout conference years, whereas the term “prostitute” decreased over time.

Conclusions

The results of this study highlight changes in HIV terminology use over 25 years, including the addition, disappearance, and changing use of terms that reflect advances in HIV research and medical practice and destigmatization of the disease. Coupled with findings from related quantitative research, HIV-related terminology recommendations based on results of this study are included. Adoption of these recommendations will further efforts to use less stigmatizing language and facilitate effective communication between health professionals and people affected by HIV.

Virological failure on first-line antiretroviral therapy; associated factors and a pragmatic approach for switching to second line therapy-evidence from a prospective cohort study in rural South-Western Uganda, 2004-2011

Introduction

We investigated factors affecting Virological failure (VF) on first line Antiretroviral Therapy (ART) and evaluated a pragmatic approach to switching to second line ART.

Methods

Between 2004 and 2011, we assessed adults taking ART. After 6 months or more on ART, participants with VL >1000 copies/ml or two successive VL > 400 copies/ml (Conventional VF) received intensified adherence counselling and continued on first-line ART for 6 more months, after which participants who still had VL > 1000 copies/ml (Pragmatic VF) were switched to second line ART. VF rates were calculated and predictors of failure were found by fitting logistic regression and Cox proportional hazards models.

Results

The 316 participants accrued 1036 person years at risk (pyar), 84 (26.6%) had conventional VF (rate 8.6 per 100 pyar) of whom 28 (33.3%) had pragmatic VF (rate 2.7 per 100 pyar). Independent predictors of conventional VF were; alcohol consumption, (adjusted Hazard Ratio; aHR = 1.71, 95% CI 1.05-2.79, P = 0.03) and ART adherence: per 10% decrease in proportion of adherent visits, (aHR = 1.83, 95% CI 1.50-2.23; P < 0.001). Using reference age group < 30 years, among conventional failures, the adjusted odds ratio (aOR) of pragmatic failure for age group 30-39 years were 0.12, 95% CI 0.03-0.57, P = 0.02 and for age group > 40 years were 0.14, 95%CI 0.03-0.71, P = 0.02. Alcohol consumers had a threefold odds of pragmatic failure than non-alcohol consumers (aOR = 3.14, 95%CI 0.95-10.34, P = 0.06).

Conclusion

A pragmatic VF approach is essential to guide switching to second line ART. Patient tailored ART adherence counselling among young patients and alcohol users is recommended.

Blood biomarkers of expressed and inducible HIV-1

OBJECTIVE

To define the relationships between molecular measures of viral persistence in blood (i.e., plasma viremia, cellular HIV-1 DNA, and mRNA) and expressed or inducible virus from resting CD4 T cells of individuals on suppressive antiretroviral therapy.

DESIGN

We compared molecular measurements of HIV-1 in plasma and in uncultured peripheral blood mononuclear cells (PBMCs) to the levels of virions produced by either unstimulated or phorbol myristate acetate and ionomycin (PMA/iono)-stimulated PBMC or resting CD4 T cells from 21 donors on suppressive antiretroviral therapy.

RESULTS

We found that unstimulated virion release from cultured resting CD4 T cells was positively correlated with the levels of plasma viremia in vivo (Spearman rho = 0.67, P = 0.0017). We also found that levels of both cellular HIV-1 DNA and unspliced HIV-1 mRNA per million uncultured PBMC were positively correlated with the levels of inducible virion release from both PMA/iono-stimulated PBMC (total HIV-1 DNA: rho = 0.64, P = 0.0017; unspliced HIV-1 RNA: rho = 0.77, P < 0.001) and PMA/iono-stimulated resting CD4 T cells (total HIV-1 DNA: rho = 0.75, P < 0.001; unspliced HIV-1 RNA: rho = 0.75, P < 0.001).

CONCLUSION

These results show for the first time that there are strong associations between in-vivo measures of HIV-1 persistence and ex-vivo measures of spontaneous and inducible virus production from cultured PBMC and resting CD4 T cells. Findings from this study provide insight into the biology of HIV-1 persistence and suggest methods to guide the evaluation of clinical strategies to reduce the size of the viral reservoir.

The Aging Brain With HIV Infection: Effects of Alcoholism or Hepatitis C Comorbidity

As successfully treated individuals with Human Immunodeficiency Virus (HIV)-infected age, cognitive and health challenges of normal aging ensue, burdened by HIV, treatment side effects, and high prevalence comorbidities, notably, Alcohol Use Disorders (AUD) and Hepatitis C virus (HCV) infection. In 2013, people over 55 years old accounted for 26% of the estimated number of people living with HIV (~1.2 million). The aging brain is increasingly vulnerable to endogenous and exogenous insult which, coupled with HIV infection and comorbid risk factors, can lead to additive or synergistic effects on cognitive and motor function. This paper reviews the literature on neuropsychological and in vivo Magnetic Resonance Imaging (MRI) evaluation of the aging HIV brain, while also considering the effects of comorbidity for AUD and HCV.

Next generation fixed dose combination pharmacotherapies for treating HIV

INTRODUCTION

Treatment options for patients with HIV-1 infection have grown over the past two decades to include multiple fixed-dose combination pharmacotherapies that have greatly simplified administration of antiretroviral therapy (ART) for both patients and providers. Effective virologic control can often be achieved with once-daily use of a single-tablet regimen. Over the past three years, ART drug development has focused on the next generation of fixed-dose combinations for initial and maintenance therapy with improved efficacy, safety and tolerability.

AREAS COVERED

This review covers pre-clinical and clinical data searched through PubMed and presented at major conferences through November 2017.

EXPERT OPINION

Currently available single-tablet regimens have clinical limitations related to adverse event profiles, drug-drug and drug-food interactions and variable barriers to resistance. Anticipated advances in ART fixed-dose combinations promise combinations of current multiple tablet regimens into single tablets, as well as combinations with novel drugs with improved safety and tolerability. The traditional dogma of effective ART containing at least three active antiretroviral drugs is being challenged by promising data to support efficacy of certain regimens containing two drugs. Implementation of next generation ART will bring to light issues of clinical preference and cost-effectiveness as patents of existing drugs expire and more generic formulations become available.

Polypharmacology in HIV inhibition: can a drug with simultaneous action against two relevant targets be an alternative to combination therapy?

HIV infection still has a serious health and socio-economical impact and is one of the primary causes of morbidity and mortality all over the world. HIV infection and the AIDS pandemic are still matters of great concern, especially in less developed countries where the access to highly active antiretroviral therapy (HAART) is limited. Patient compliance is another serious drawback. Nowadays, HAART is the treatment of choice although it is not the panacea. Despite the fact that it suppresses viral replication at undetectable viral loads and prevents progression of HIV infection into AIDS HAART has several pitfalls, namely, long-term side-effects, drug resistance development, emergence of drug-resistant viruses, low compliance and the intolerance of some patients to these drugs. Moreover, another serious health concern is the event of co-infection with more than one pathogen at the same time (e.g. HIV and HCV, HBV, herpes viruses, etc). Currently, the multi-target drug approach has become an exciting strategy to address complex diseases and overcome drug resistance development. Such multifunctional molecules combine in their structure pharmacophores that may simultaneously interfere with multiple targets and their use may eventually be more safe and efficacious than that involving a mixture of separate molecules because of avoidance or delay of drug resistance, lower incidence of unwanted drug-drug interactions and improved compliance. In this review we focus on multifunctional molecules with dual activity against different targets of the HIV life cycle or able to block replication, not only of HIV but also of other viruses that are often co-pathogens of HIV. The different approaches are documented by selected examples.

From CD4-Based Initiation to Treating All HIV-Infected Adults Immediately: An Evidence-Based Meta-analysis

Background

The World Health Organization (WHO) Consolidated antiretroviral therapy (ART) guidelines set the CD4⁺ T-cell counts threshold to 500 cells/mm³ in 2013, and 2015 guidelines recommend treating all HIV-infected adults regardless of their CD4⁺ T-cell counts. To inform the decision-making around ART guidelines for people living with HIV, we systematically reviewed the literature to estimate differences in clinical benefits between individuals starting treatment with baseline CD4⁺ T-cell counts ≥500 cells/mm³ (early initiation) as compared to <500 cells/mm³ (deferred initiation).

Methods

We systematically searched the electronic databases and abstracts for randomized controlled trials (RCT) and observational studies. Outcomes were mortality, AIDS progression, AIDS or death, immunologic recovery, and virologic suppression. We pooled data across studies and performed analyses of effect sizes.

Results

We identified 13 studies comparing early and deferred treatment. The pooled risk ratio (RR) of mortality of 11 observational studies was 0.90 (95% CI 0.82–0.99), with moderate heterogeneity (I² = 53%). The pooled RR for progression to AIDS from two observational studies was 0.77 (95% CI 0.47–1.24). Five observational studies found a pooled RR of death or AIDS of 0.94 (95% CI 0.93–0.95). For the outcome of immunologic recovery, defined as CD4⁺ T-cell counts reaching at least 800 cells/mm³ after ART, one observational study found early initiation of ART had an HR (hazard ratio) of 2.39 (95% CI 1.93–2.96). The pooled RR of viral suppression (a viral load <50 copies/ml) after 9 months from one cohort was 1.04 (95% CI 0.99–1.09).

Conclusion

Mortality risk and risk for AIDS appear to be reduced among people living with HIV with early initiation of ART, based on current WHO guidelines, as compared to those with deferred initiation of ART (<500 cells/mm³).

The role of latency reversal agents in the cure of HIV: A review of current data

The definitive cure for human immunodeficiency virus type-1 (HIV) infection is represented by the eradication of the virus from the patient's body. To reach this result, cells that are infected but do not produce the virus must become recognizable to be killed by the immune system. For this purpose, drugs defined "latency reverting agents" (LRA) that reactivate viral production are under investigation. A few clinical studies have been performed in HIV-infected patients treated with LRA and combined antiretroviral therapy (cART). The strategy is thus to combine cART and LRA to reactivate the virus and unmask latently infected cells that, because of cART, cannot produce a fully competent form of the virus. Unmasked cells can present viral antigens to the immune system, that ultimately recognizes and kills such latently infected cells. This review reports and discusses recent studies that have been published on this topic.

Thirty years of confronting the Aids epidemic in Brazil, 1985-2015

The Brazilian response to AIDS started in 1985, with government, civil society and academic community coming together with common goals. This was strengthened with the establishment in 1988 of an universal public health system (SUS), pivotal to a comprehensive and human rights-based national STD/AIDS programme, aiming at achieving equality, integrality, inclusion and fighting prejudice and discrimination. In 1996 Brazil was a pioneer in providing treatment free-of-charge to all PLHA. This article depicts achievements and setbacks that occurred in these 30 years and the perspectives for controlling and eventually eliminating HIV/AIDS. It is fair to affirm that it is possible to defeat prejudice and discrimination and to confront the unacceptable levels of disparity, fertile ground for dissemination of HIV/AIDS and other epidemics. Tools to eliminate transmission, to adequately treat PLHA, to protect their rights, to eliminate discrimination and to end AIDS are already at hand. However, the needed changes for this to happen involve expansion of access to education, including sexual education and to quality public health care to all. It is also necessary to constant confront conservatism and to combat violence and discrimination. Brazil's track record in the confrontation of AIDS is an invaluable asset to achieve these goals.

Genetically Intact but Functionally Impaired HIV-1 Env Glycoproteins in the T-Cell Reservoir

HIV-infected subjects under antiretroviral treatment (ART) harbor a persistent viral reservoir in resting CD4⁺ T cells, which accounts for the resurgence of HIV replication after ART interruption. A large majority of HIV reservoir genomes are genetically defective, but even among intact proviruses few seem able to generate infectious virus. To understand this phenomenon, we examined the function and expression of HIV envelope glycoproteins reactivated from the reservoir of four HIV-infected subjects under suppressive ART. We studied full-length genetically intact env sequences from both replicative viruses and cell-associated mRNAs. We found that these Env proteins varied extensively in fusogenicity and infectivity, with strongest functional defects found in Envs from cell-associated mRNAs. Env functional impairments were essentially explained by defects in Env protein expression. Our results support the idea that defects in HIV Env expression, preventing cytopathic or immune HIV clearance, contribute to the persistence of the HIV T-cell reservoir in vivoIMPORTANCE In most individuals, evolution of HIV infection is efficiently controlled on the long-term by combination antiviral therapies. These treatments, however, fail to eradicate HIV from the infected subjects, a failure that results both in resurgence of virus replication and in resumption of HIV pathogenicity when the treatment is stopped. HIV resurgence, in these instances, is widely assumed to emerge from a reservoir of silent virus integrated in the genomes of a small number of T lymphocytes. The silent HIV reservoir is mostly composed of heavily deleted or mutated HIV DNA. Moreover, among the seemingly intact remaining HIV, only very few are actually able to efficiently propagate in tissue culture. In this study, we find that intact HIV in the reservoir often carry strong defects in their capacity to promote fusion to neighboring cells and infection of target cells, a defect related to the function and expression of the HIV envelope glycoprotein. Impaired envelope glycoprotein expression and function could explain why cells harboring these viruses tend to remain undetected and unharmed in the reservoir.

Temporal trends of transmitted HIV drug resistance in a multinational seroconversion cohort

BACKGROUND

The rate of transmitted drug resistance (TDR) may increase with wider use of antiretroviral therapy and can contribute to therapeutic failure. We analysed time trends in TDR among HIV seroconverters.

METHODS

Using CASCADE data of individuals with well estimated dates of HIV seroconversion, we examined HIV nucleotide sequences collected prior to antiretroviral therapy use from 1996-2012. All samples were taken within 12 months of testing HIV positive. Using logistic regression, we examined the association between TDR and year of seroconversion, adjusting for confounders.

RESULTS

Of 4717 individuals seroconverting between 1996 and 2012, median (IQR) age at seroconversion was 33 (27, 39) years. The majority (3839; 92%) were male, mainly exposed through MSM (3767; 80%), and infected with subtype B (3464; 73%). Overall, 515 (11%) individuals had at least one drug resistance-related mutation; 280 individuals with nucleoside reverse transcriptase, 185 with nonnucleoside reverse transcriptase, and 144 with protease inhibitor mutations. Estimated TDR prevalence was 19.4% (8.2, 36.0) in 1996, significantly decreasing to 8.5% (5.9, 11.9) in 2012 [odds ratio (OR; 95% confidence interval (CI)) = 0.92 (0.90, 0.95) per year increase]. Individuals exposed through sex between men and women were significantly less likely to have been infected with a drug-resistant strain [OR (95% CI) = 0.59 (0.41, 0.87) compared with MSM], and there was marginal evidence that sampling during acute infection was associated with higher odds of resistance [OR (95% CI) = 1.20 (0.97, 1.7), P = 0.093] compared with later sampling.

CONCLUSION

TDR has decreased over calendar time although a significant proportion of new infections still carry resistance-related mutations.

Candidates for inclusion in a universal antiretroviral regimen: dolutegravir

PURPOSE OF REVIEW

The review addresses the role of dolutegravir (DTG) in first-line therapy. In the era of test and treat, where United Nations AIDS Program and WHO have set the ambitious targets of 90/90/90, new efficacious, well tolerated, and simple therapeutic options are needed.

RECENT FINDINGS

DTG has been tested in large clinical trials in treatment-naïve patients, showing noninferiority to raltegravir and superiority compared with efavirenz and ritonavir-boosted darunavir, respectively. The main features of DTG are reviewed in this study, including efficacy, safety, high-resistance barrier, daily treatment schedule, and coformulation as single-tablet regimen. Use of DTG in special populations is also reviewed. Tolerability, with focus in neuropsychiatric disturbances is discussed in particular. DTG has shown high efficacy level, tested in males and females, has no limitations in patients with renal and/or hepatic impairment and is available as single drug (to be combined with two nucleoside reverse transcriptase inhibitors in fixed combinations) or as a single-tablet regimen combined with abacavir and lamivudine.

SUMMARY

DTG is an excellent candidate for initial therapy in HIV-infected patients. If safety of DTG in pregnant women are confirmed by ongoing studies, DTG might become the first option in WHO antiretroviral guidelines.

In Vitro Transduction and Target-Mutagenesis Efficiency of HIV-1 pol Gene Targeting ZFN and CRISPR/Cas9 Delivered by Various Plasmids and/or Vectors: Toward an HIV Cure

Efficiency of artificial restriction enzymes toward curing HIV has only been separately examined, using differing delivery vehicles. We compared the in vitro transduction and target-mutagenesis efficiency of consortium plasmid and adenoviral vector delivered HIV-1 pol gene targeting zinc finger nuclease (ZFN) with CRISPR/Cas, Custom-ZFN, CRISPR-Cas-9, and plasmids and vectors (murCTSD_pZFN, pGS-U-gRNA, pCMV-Cas-D01A, Ad5-RGD); cell lines (TZM-bl and ACH-2/J-Lat cells); and the latency reversing agents prostratin, suberoylanilide hydroxamic acid, and phorbol myristate acetate. Cell lines were grown in either Dulbecco's modified Eagle's medium or Roswell Park Memorial Institute with the antibiotics kanamycin, zeocin, and efavirenz. Efficiency was assayed by GFP/luciferase activity and/or validated by yeast MEL1 reporter assay, CEL1 restriction fragment assay, and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Ad5-RGD vectors had better transduction efficiency than murCTSD and pGS-U-gRNA/pCMV-Cas-D01A plasmids. CRISPR/Cas9 exhibited better target-mutagenesis efficiency relative to ZFN (delivered by either plasmid or Ad5 vector) based on gel electrophoresis of pol gene amplicons within ACH-2 and J-Lat cells. Ad-5-RGD vectors enhanced target mutagenesis of ZFN, relative to murCTSD_pZFN plasmids, to levels of CRISPR/Cas9 plasmids. Similar reduction of luciferase activity among TZM-bl treated with Ad5-ZFN vectors relative to CRISPR/Cas-9 and murCTSD_pZFN plasmids was observed on challenge with HIV-1. qRT-PCR of HIV-1 pol gene transcripts affirmed that Ad5 (RGD) vectors enhanced target mutagenesis of ZFN. Whereas CRISPR/Cas-9 may possess inherent superior target-mutagenesis efficiency; the efficiency of ZFN (off-target toxicity withstanding) can be enhanced by altering delivery vehicle from plasmid to Ad5 (RGD) vectors.

Noncoding RNAs in Retrovirus Replication

Although a limited percentage of the genome produces proteins, approximately 90% is transcribed, indicating important roles for noncoding RNA (ncRNA). It is now known that these ncRNAs have a multitude of cellular functions ranging from the regulation of gene expression to roles as structural elements in ribonucleoprotein complexes. ncRNA is also represented at nearly every step of viral life cycles. This chapter will focus on ncRNAs of both host and viral origin and their roles in retroviral life cycles. Cellular ncRNA represents a significant portion of material packaged into retroviral virions and includes transfer RNAs, 7SL RNA, U RNA, and vault RNA. Initially thought to be random packaging events, these host RNAs are now proposed to contribute to viral assembly and infectivity. Within the cell, long ncRNA and endogenous retroviruses have been found to regulate aspects of the retroviral life cycle in diverse ways. Additionally, the HIV-1 transactivating response element RNA is thought to impact viral infection beyond the well-characterized role as a transcription activator. RNA interference, thought to be an early version of the innate immune response to viral infection, can still be observed in plants and invertebrates today. The ability of retroviral infection to manipulate the host RNAi pathway is described here. Finally, RNA-based therapies, including gene editing approaches, are being explored as antiretroviral treatments and are discussed.

BET inhibitors RVX-208 and PFI-1 reactivate HIV-1 from latency

Persistent latent reservoir in resting CD4+ T cells is a major obstacle in curing HIV-1 infection. Effective strategies for eradication of the HIV-1 reservoir are urgently needed. We report here for the first time that two BET inhibitors, RVX-208, which has entered phase II clinical trials for diverse cardiovascular disorders, and PFI-1, which has been widely studied in oncology, can reactivate HIV-1 from latency. RVX-208 and PFI-1 treatment alone or in combination with other latency reversing agents efficiently reactivated HIV-1 transcription through an up-regulation of P-TEFb by increasing CDK9 Thr-186 phosphorylation in latently infected Jurkat T cells in vitro. The two BET inhibitors also reactivated HIV-1 transcription in cART treated patient-derived resting CD4+ T cells ex vivo, without influence on global immune cell activation. Our findings, in combination with previous reports, further confirm that BET inhibitors are a group of leading compounds for combating HIV-1 latency for viral eradication.

Human influences on evolution, and the ecological and societal consequences

Humans have dramatic, diverse and far-reaching influences on the evolution of other organisms. Numerous examples of this human-induced contemporary evolution have been reported in a number of 'contexts', including hunting, harvesting, fishing, agriculture, medicine, climate change, pollution, eutrophication, urbanization, habitat fragmentation, biological invasions and emerging/disappearing diseases. Although numerous papers, journal special issues and books have addressed each of these contexts individually, the time has come to consider them together and thereby seek important similarities and differences. The goal of this special issue, and this introductory paper, is to promote and expand this nascent integration. We first develop predictions as to which human contexts might cause the strongest and most consistent directional selection, the greatest changes in evolutionary potential, the greatest genetic (as opposed to plastic) changes and the greatest effects on evolutionary diversification We then develop predictions as to the contexts where human-induced evolutionary changes might have the strongest effects on the population dynamics of the focal evolving species, the structure of their communities, the functions of their ecosystems and the benefits and costs for human societies. These qualitative predictions are intended as a rallying point for broader and more detailed future discussions of how human influences shape evolution, and how that evolution then influences species traits, biodiversity, ecosystems and humans.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.

The Role of Brincidofovir in Preparation for a Potential Smallpox Outbreak

Smallpox (variola) virus is considered a Category A bioterrorism agent due to its ability to spread rapidly and the high morbidity and mortality rates associated with infection. Current recommendations recognize the importance of oral antivirals and call for having at least two smallpox antivirals with different mechanisms of action available in the event of a smallpox outbreak. Multiple antivirals are recommended due in large part to the propensity of viruses to become resistant to antiviral therapy, especially monotherapy. Advances in synthetic biology heighten concerns that a bioterror attack with variola would utilize engineered resistance to antivirals and potentially vaccines. Brincidofovir, an oral antiviral in late stage development, has proven effective against orthopoxviruses in vitro and in vivo, has a different mechanism of action from tecovirimat (the only oral smallpox antiviral currently in the US Strategic National Stockpile), and has a resistance profile that reduces concerns in the scenario of a bioterror attack using genetically engineered smallpox. Given the devastating potential of smallpox as a bioweapon, preparation of a multi-pronged defense that accounts for the most obvious bioengineering possibilities is strategically imperative.

Dolutegravir-lamivudine as initial therapy in HIV-1 infected, ARV-naive patients, 48-week results of the PADDLE (Pilot Antiretroviral Design with Dolutegravir LamivudinE) study

Introduction: A proof-of-concept study was designed to evaluate the antiviral efficacy, safety and tolerability of a two-drug regimen with dolutegravir 50 mg once daily (QD) plus lamivudine 300 mg once daily as initial highly active antiretroviral therapy (HAART) among antiretroviral (ARV)-naive patients.

Methods: PADDLE is a pilot study including 20 treatment-naive adults. To be selected, participants had no IAS-USA-defined resistance, HIV-1 RNA ≤100,000 copies/mL at screening and negative HBsAg. Plasma viral load (pVL) was measured at baseline; days 2, 4, 7, 10, 14, 21 and 28; weeks 6, 8 and 12; and thereafter every 12 weeks up to 96 weeks. Primary endpoint was the proportion of patients with HIV-1 RNA <50 copies/mL in an intention to treat (ITT)-exposed analysis at 48 weeks (the FDA snapshot algorithm).

Results: Median HIV-1 RNA at entry was 24,128 copies/mL (interquartile range (IQR): 11,686–36,794). Albeit as per protocol, all patients had pVL ≤100,000 copies/mL at screening as required by inclusion criteria, four patients had ≥100,000 copies/mL at baseline. Median baseline CD4+ T-cell count was 507 per cubic millimetre (IQR: 296–517). A rapid decline in pVL was observed (median VL decay from baseline to week 12 was 2.74 logs). All patients were suppressed at week 8 onwards up to week 24. At week 48, 90% (18/20) reached the primary endpoint of a pVL <50 copies/mL. Median change in CD4 cell count between baseline and week 48 was 267 cells/mm³ (IQR: 180–462). No major tolerability/toxicity issues were observed. Nineteen patients completed 48 weeks of the study, and one patient (with undetectable VL at last visit) committed suicide. One patient presented a low-level protocol-defined confirmed virological failure at week 36, being the only observed failure. This patient had pVL <50 copies/mL at the end-of-study visit without having changed the two-drug regimen. Observed failure rate was 5%. This is the first report of integrase strand transfer inhibitor/lamivudine dual regimen in ARV-naive patients.

Conclusions: This novel dual regimen of dolutegravir and lamivudine warrants further clinical research and consideration as a potential therapeutic option for ARV-therapy-naive patients.

ClinicalTrials.gov Identifier: NCT02211482.

Short-Term Antiretroviral Treatment Recommendations Based on Sensitivity Analysis of a Mathematical Model for HIV Infection of CD₄⁺Τ Cells

HIV infection is one of the most difficult infections to control and manage. The most recent recommendations to control this infection vary according to the guidelines used (US, European, WHO) and are not patient-specific. Unfortunately, no two individuals respond to infection and treatment quite the same way. The purpose of this paper is to make use of the uncertainty and sensitivity analysis to investigate possible short-term treatment options that are patient-specific. We are able to identify the most significant parameters that are responsible for ART outcome and to formulate some insights into the ART success.

A historical review of HIV prevention and care initiatives in British Columbia, Canada: 1996-2015

INTRODUCTION

British Columbia has made significant progress in the treatment and prevention of HIV since 1996, when Highly Active Antiretroviral Therapy (HAART) became available. However, we currently lack a historical summary of HIV prevention and care interventions implemented in the province since the introduction of HAART and how they have shaped the HIV epidemic. Guided by a socio-ecological framework, we present a historical review of biomedical and health services, community and structural interventions implemented in British Columbia from 1996-2015 to prevent HIV transmission or otherwise enhance the cascade of HIV care.

METHODS

We constructed a historical timeline of HIV interventions implemented in BC between 1996 and 2015 by reviewing publicly available reports, guidelines and other documents from provincial health agencies, community organizations and AIDS service organizations, and by conducting searches of peer-reviewed literature through PubMed and Ovid MEDLINE. We collected further programmatic information by administering a data collection form to representatives from BC's regional health authorities and an umbrella agency representing 45 AIDS Service organizations. Using linked population-level health administrative data, we identified key phases of the HIV epidemic in British Columbia, as characterized by distinct changes in HIV incidence, HAART uptake and the provincial HIV response.

RESULTS AND DISCUSSION

In total, we identified 175 HIV prevention and care interventions implemented in BC from 1996 to 2015. We identify and describe four phases in BC's response to HIV/AIDS: the early HAART phase (1996-1999); the harm reduction and health service scale-up phase (2000-2005); the early Treatment as Prevention phase (2006-2009); and the STOP HIV/AIDS phase (2010-present). In doing so, we provide an overview of British Columbia's universal and centralized HIV treatment system and detail the role of community-based and provincial stakeholders in advancing innovative prevention and harm reduction approaches, as well as "seek, test, treat and retain" strategies.

CONCLUSIONS

The review provides valuable insight into British Columbia's HIV response, highlights emerging priorities, and may inform future efforts to evaluate the causal impact of interventions.

Reactivation of HIV-1 from Latency by an Ingenol Derivative from Euphorbia Kansui

Cells harboring latent HIV-1 pose a major obstacle to eradication of the virus. The ‘shock and kill’ strategy has been broadly explored to purge the latent reservoir; however, none of the current latency-reversing agents (LRAs) can safely and effectively activate the latent virus in patients. In this study, we report an ingenol derivative called EK-16A, isolated from the traditional Chinese medicinal herb Euphorbia kansui, which displays great potential in reactivating latent HIV-1. A comparison of the doses used to measure the potency indicated EK-16A to be 200-fold more potent than prostratin in reactivating HIV-1 from latently infected cell lines. EK-16A also outperformed prostratin in ex vivo studies on cells from HIV-1-infected individuals, while maintaining minimal cytotoxicity effects on cell viability and T cell activation. Furthermore, EK-16A exhibited synergy with other LRAs in reactivating latent HIV-1. Mechanistic studies indicated EK-16A to be a PKCγ activator, which promoted both HIV-1 transcription initiation by NF-κB and elongation by P-TEFb signal pathways. Further investigations aimed to add this compound to the therapeutic arsenal for HIV-1 eradication are in the pipeline.

Relative efficacy of T cell stimuli as inducers of productive HIV-1 replication in latently infected CD4 lymphocytes from patients on suppressive cART

Quantification of cell-associated replication-competent HIV, in blood samples from patients with undetectable plasma viremia, requires specialized culture conditions that include exogenous pan T cell stimulation. Different research groups have used several stimuli for this purpose; however, the relative efficacies of these T cell stimuli to induce productive HIV replication from latently infected cells ex vivo have not been systematically evaluated. To this end, we compared four commonly used T cell stimuli: 1) irradiated allogeneic cells plus phytohaemagglutinin (PHA); 2) PHA alone; 3) phorbol myristate acetate plus Ionomycin; and 4) immobilized αCD3 plus αCD28 antibodies. End-point dilutions of patient CD4 T cells were performed, using virion RNA production to quantify HIV induction. Our results demonstrated that these activation approaches were not equivalent and that antibody cross-linking of CD3 and CD28 membrane receptors was the most effective means to activate HIV replication from a resting cell state, closely followed by stimulation with irradiated allogeneic cells plus PHA.

The Latent Reservoir for HIV-1: How Immunologic Memory and Clonal Expansion Contribute to HIV-1 Persistence

Combination antiretroviral therapy (ART) for HIV-1 infection reduces plasma virus levels to below the limit of detection of clinical assays. However, even with prolonged suppression of viral replication with ART, viremia rebounds rapidly after treatment interruption. Thus, ART is not curative. The principal barrier to cure is a remarkably stable reservoir of latent HIV-1 in resting memory CD4(+) T cells. In this review, we consider explanations for the remarkable stability of the latent reservoir. Stability does not appear to reflect replenishment from new infection events but rather normal physiologic processes that provide for immunologic memory. Of particular importance are proliferative processes that drive clonal expansion of infected cells. Recent evidence suggests that in some infected cells, proliferation is a consequence of proviral integration into host genes associated with cell growth. Efforts to cure HIV-1 infection by targeting the latent reservoir may need to consider the potential of latently infected cells to proliferate.

Engineering hematopoietic stem cells toward a functional cure of human immunodeficiency virus infection

The battle with human immunodeficiency virus (HIV) has been ongoing for more than 30 years, and although progress has been made, there are still significant challenges remaining. A few unique features render HIV to be one of the toughest viruses to conquer in the modern medicine era, such as the ability to target the host immune system, persist by integrating into the host genome and adapt to a hostile environment such as a single anti-HIV medication by continuously evolving. The finding of combination anti-retroviral therapy (cART) about 2 decades ago has transformed the treatment options for HIV-infected patients and significantly improved patient outcomes. However, finding an HIV cure has proven to be extremely challenging with the only known exception being the so-called "Berlin patient," whose immune system was replaced by stem cell transplants from a donor missing one of HIV's key co-receptors (CCR5). The broad application of this approach is limited by the requirement of an HLA-matched donor who is also homozygous for the rare CCR5 delta32 deletion. On the other hand, the Berlin patient provided the proof of concept of a potential cure for HIV using HIV-resistant hematopoietic stem cells (HSCs), revitalizing the hope to find an HIV cure that is broadly applicable. Here we will review strategies and recent attempts to engineer HIV-resistant HSCs as a path to an HIV cure.

On the way to find a cure: Purging latent HIV-1 reservoirs

Introduction of cART in 1996 has drastically increased the life expectancy of people living with HIV-1. However, this treatment has not allowed cure as cessation of cART is associated with a rapid viral rebound. The main barrier to the eradication of the virus is related to the persistence of latent HIV reservoirs. Evidence is now accumulating that purging the HIV-1 reservoir might lead to a cure or a remission. The most studied strategy is the so called "shock and kill" therapy. This strategy is based on reactivation of dormant viruses from the latently-infected reservoirs (the shock) followed by the eradication of the reservoirs (the kill). This review focuses mainly on the recent advances made in the "shock and kill" therapy. We believe that a cure or a remission will come from combinatorial approaches i.e. combination of drugs to reactivate the dormant virus from all the reservoirs including the one located in sanctuaries, and combination of strategies boosting the immune system. Alternative strategies based on cell and gene therapy or based in inducing deep latency, which are evoked in this review reinforce the idea that at least a remission is attainable.

Trends in racial/ethnic disparities of new AIDS diagnoses in the United States, 1984-2013

PURPOSE

In the United States, human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) disproportionately impacts racial/ethnic minorities. We describe and evaluate trends in the Black-White and Hispanic-White disparities of new AIDS diagnoses from 1984 to 2013 in the United States.

METHODS

AIDS diagnosis rates by race/ethnicity for people ≥13 years were calculated using national HIV surveillance and Census data. Black-White and Hispanic-White disparities were measured as rate ratios. Joinpoint Regression was used to identify time periods across which to estimate rate-ratio trends. We calculated the estimated annual percent change in disparities for each time period using log-normal linear regression modeling.

RESULTS

Black-White disparity increased from 1984 to 1990, followed by a large increase from 1991 to 1996, and a smaller increase from 1997 to 2001. Black-White disparity moderated from 2002 to 2005 and rose again from 2006 to 2013. Hispanic-White disparity increased from 1984 to 1997 but declined after 1998. Black-White and Hispanic-White disparities increased for men who have sex with men during 2008 to 2013.

CONCLUSIONS

Recent increases in racial/ethnic disparities of AIDS diagnoses were observed and may be due in part to care continuum inequalities. We suggest assessing disparities in AIDS diagnoses as a high-level measure to capture changes at multiple stages of the care continuum collectively. Future research should examine determinants of racial/ethnic differences at each step of the continuum to better identify characteristics driving disparities.

Overview of cancer incidence and mortality among people living with HIV/AIDS in British Columbia, Canada: Implications for HAART use and NADM development

Background

The objective of this study is to evaluate the incidence of non-AIDS defining malignancies (NADMs) among people living with HIV/AIDS (PLWHA) in British Columbia, focusing on clinical correlates, highly active antiretroviral therapy (HAART) use, and survival, in order to elucidate mechanisms for NADM development.

Methods

A retrospective population based analysis was carried out for individuals with HIV/AIDS that began their treatment between 1996 and 2008.

Results

There were 145 (2.95%) NADMs and 123 (2.50%) AIDS defining malignancies (ADMs) identified in 4918 PLWHA in the study population. NADMs were represented by a range of cancer types including, most commonly, lung cancer, followed by anal, breast, head/neck, prostate, liver, rectal, and renal cancers. PLWHA had a SIR of 2.05 (CI:1.73, 2.41) for the development of NADMs compared to individuals without an HIV/AIDS diagnosis in the general population. Independent factors significantly associated with a NADM were: male gender, older age, lower CD4 cell counts, previous NADM, absence of HAART (non-HAART versus HAART) and treatment during the early-HAART era (before 2000 versus after 2000).

Conclusions

NADMs represent an important source of morbidity for PLWHA. Use of HAART with its associated improvement in immune-restoration, and tailored targeted cancer screening interventions, may be beneficial and improve outcomes in this unique patient population.

The HIV care cascade: Japanese perspectives

Japan has been known as a low HIV-prevalence country with a concentrated epidemic among high-risk groups. However, it has not been determined whether Japan meets the 90-90-90 goals set by the Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO). Moreover, to date, the HIV care cascade has not been examined. We estimated the total number of diagnosed people living with HIV/AIDS (PLWHA) (n = 22,840) based on legal reports to the Ministry of Health, Labour and Welfare by subtracting the number of foreigners who left Japan (n = 2,273) and deaths (n = 2,321) from the cumulative diagnosis report (n = 27,434). The number of total undiagnosed PLWHA was estimated by age and sex specific HIV-positive rates observed among first-time blood donors between 2011–2015 in Japan. Our estimates show that 14.4% (n = 3,830) of all PLWHA (n = 26,670) were undiagnosed in Japan at the end of 2015. The number of patients retained in care (n = 20,615: 77.3% of PLWHA), the percentage of those on antiretroviral therapy (n = 18,921: 70.9% of PLWHA) and those with suppressed viral loads (<200 copies/mL; n = 18,756: 70.3% of PLWHA) were obtained through a questionnaire survey conducted in the AIDS Core Hospitals throughout the country. According to these estimates, Japan failed to achieve the first two of the three UNAIDS/WHO targets (22,840/26,670 = 85.6% of HIV-positive cases were diagnosed; 18,921/22,840 = 82.8% of those diagnosed were treated; 18,756/18,921 = 99.1% of those treated experienced viral suppression). Although the antiretroviral treatment uptake and success after retention in medical care appears to be excellent in Japan, there are unmet needs, mainly at the surveillance level before patients are retained in care. The promotion of HIV testing and treatment programs among the key affected populations (especially men who have sex with men) may contribute to further decreasing the HIV epidemic and achieving the UNAIDS/WHO targets in Japan.

The absence of hyperbilirubinaemia is highly predictive of treatment failure in advanced HIV-infected patients treated with indinavir

In order to determine prognostic factors associated with treatment failure (TF) in advanced HIV-infected patients treated with a regimen including indinavir, a prospective cohort study of 80 patients was set up between 1 March and 31 December 1996. TF time was calculated using the Kaplan–Meier method, from treatment induction to the first of the following events: treatment modification for adverse event or lack of significant virological and/or immunological response, AIDS-defining diagnosis or death. Date of point was 31 December 1998. Multivariate analysis was performed using a Cox model. At baseline, 60% of the patients were AIDS-free, median viral load and CD4+ count were respectively 4.8 log/ml and 79/μl. After a median follow-up of 26 months, 70% of the patients experienced a TF in a median time of 8 months. Seventy-two per cent presented an hyperbilirubinaemia (>2 mg/dl). In multivariate analysis, initial AIDS stage (hazard ratios [HR]=1.94, P=0.04) and digestive intolerance (HR=2.32, P=0.003) were predictive of TF. Conversely, hyperbilirubinaemia was associated with a better outcome (HR=0.35, P<0.0001). These 2 latter parameters very likely reflected patients' treatment compliance.

Organelles - understanding noise and heterogeneity in cell biology at an intermediate scale

Many studies over the years have shown that non-genetic mechanisms for producing cell-to-cell variation can lead to highly variable behaviors across genetically identical populations of cells. Most work to date has focused on gene expression noise as the primary source of phenotypic heterogeneity, yet other sources may also contribute. In this Commentary, we explore organelle-level heterogeneity as a potential secondary source of cellular 'noise' that contributes to phenotypic heterogeneity. We explore mechanisms for generating organelle heterogeneity and present evidence of functional links between organelle morphology and cellular behavior. Given the many instances in which molecular-level heterogeneity has been linked to phenotypic heterogeneity, we posit that organelle heterogeneity may similarly contribute to overall phenotypic heterogeneity and underline the importance of studying organelle heterogeneity to develop a more comprehensive understanding of phenotypic heterogeneity. Finally, we conclude with a discussion of the medical challenges associated with phenotypic heterogeneity and outline how improved methods for characterizing and controlling this heterogeneity may lead to improved therapeutic strategies and outcomes for patients.

Small-molecule HIV-1 entry inhibitors targeting gp120 and gp41: a patent review (2010-2015)

INTRODUCTION

It is essential to discover and develop small-molecule HIV-1 entry inhibitors with suitable pharmaceutical properties. Areas covered: We review the development of small-molecule HIV-1 entry inhibitors as evidenced in patents, patent applications, and related research articles published between 2010 and 2015. Expert opinion: HIV-1 Env gp120 and gp41 are important targets for development of HIV-1 entry inhibitors. The Phe43 pocket in gp120 and the highly conserved hydrophobic pocket on gp41 NHR-trimer are important targets for identification of HIV-1 attachment and fusion inhibitors, respectively. Compounds that bind to Phe43 pocket can block viral gp120 binding to CD4 on T cells, thus inhibiting HIV-1 attachment. However, most compounds targeting Phe43 pocket identified so far are HIV-1 entry agonists with the ability to enhance infectivity of HIV-1 in CD4-negative cells. Therefore, it is essential to identify HIV-1 entry antagonist-based HIV-1 attachment/entry inhibitors. Compounds binding to the gp41 hydrophobic pocket may inhibit CHR binding to the gp41 NHR trimer, thus blocking six-helix bundle formation and gp41-mediated virus-cell fusion. However, most lead compounds targeting this pocket have low potency, possibly because the pocket is too big or too deep. Therefore, it is necessary to identify other pockets in gp41 for developing HIV-1 fusion/entry inhibitors.

Assays to Measure Latency, Reservoirs, and Reactivation

HIV-1 persists even in patients who are successfully treated with combination antiretroviral therapy. The major barrier to cure is a small pool of latently infected resting CD4⁺ T cells carrying an integrated copy of the viral genome that is not expressed while the cells remain in a resting state. Targeting this latent reservoir is a major focus of HIV-1 cure research, and the development of a rapid and scalable assay for the reservoir is a rate-limiting step in the search for a cure. The most commonly used assays are standard PCR assays targeting conserved regions of the HIV-1 genome. However, because the vast majority of HIV-1 proviruses are defective, such assays may not accurately capture changes in the minor subset of proviruses that are replication-competent and that pose a barrier to cure. On the other hand, the viral outgrowth assay that was used to initially define the latent reservoir may underestimate reservoir size because not all replication-competent proviruses are induced by a single round of T cell activation in this assay. Therefore, this assay is best regarded as a definitive minimal estimate of reservoir size. The best approach may be to measure all of the proviruses with the potential to cause viral rebound. A variety of novel assays have recently been described. Ultimately, the assay that best predicts time to viral rebound will be the most useful to the cure effort.

Nuclear landscape of HIV-1 infection and integration

To complete its life cycle, HIV-1 enters the nucleus of the host cell as reverse-transcribed viral DNA. The nucleus is a complex environment, in which chromatin is organized to support different structural and functional aspects of cell physiology. As such, it represents a challenge for an incoming viral genome, which needs to be integrated into cellular DNA to ensure productive infection. Integration of the viral genome into host DNA depends on the enzymatic activity of HIV-1 integrase and involves different cellular factors that influence the selection of integration sites. The selection of integration site has functional consequences for viral transcription, which usually follows the integration event. However, in resting CD4⁺ T cells, the viral genome can be silenced for long periods of time, which leads to the generation of a latent reservoir of quiescent integrated HIV-1 DNA. Integration represents the only nuclear event in the viral life cycle that can be pharmacologically targeted with current therapies, and the aspects that connect HIV-1 nuclear entry to HIV-1 integration and viral transcription are only beginning to be elucidated.

Envelope-specific antibodies and antibody-derived molecules for treating and curing HIV infection

HIV-1 is a retrovirus that integrates into host chromatin and can remain transcriptionally quiescent in a pool of immune cells. This characteristic enables HIV-1 to evade both host immune responses and antiretroviral drugs, leading to persistent infection. Upon reactivation of proviral gene expression, HIV-1 envelope (HIV-1 Env) glycoproteins are expressed on the cell surface, transforming latently infected cells into targets for HIV-1 Env-specific monoclonal antibodies (mAbs), which can engage immune effector cells to kill productively infected CD4+ T cells and thus limit the spread of progeny virus. Recent innovations in antibody engineering have resulted in novel immunotherapeutics such as bispecific dual-affinity re-targeting (DART) molecules and other bi- and trispecific antibody designs that can recognize HIV-1 Env and recruit cytotoxic effector cells to kill CD4+ T cells latently infected with HIV-1. Here, we review these immunotherapies, which are designed with the goal of curing HIV-1 infection.

Evaluating the Impact of a HIV Low-Risk Express Care Task-Shifting Program: A Case Study of the Targeted Learning Roadmap

In conducting studies on an exposure of interest, a systematic roadmap should be applied for translating causal questions into statistical analyses and interpreting the results. In this paper we describe an application of one such roadmap applied to estimating the joint effect of both time to availability of a nurse-based triage system (low risk express care (LREC)) and individual enrollment in the program among HIV patients in East Africa. Our study population is comprised of 16,513 subjects found eligible for this task-shifting program within 15 clinics in Kenya between 2006 and 2009, with each clinic starting the LREC program between 2007 and 2008. After discretizing follow-up into 90-day time intervals, we targeted the population mean counterfactual outcome (i. e. counterfactual probability of either dying or being lost to follow up) at up to 450 days after initial LREC eligibility under three fixed treatment interventions. These were (i) under no program availability during the entire follow-up, (ii) under immediate program availability at initial eligibility, but non-enrollment during the entire follow-up, and (iii) under immediate program availability and enrollment at initial eligibility. We further estimated the controlled direct effect of immediate program availability compared to no program availability, under a hypothetical intervention to prevent individual enrollment in the program. Targeted minimum loss-based estimation was used to estimate the mean outcome, while Super Learning was implemented to estimate the required nuisance parameters. Analyses were conducted with the ltmle R package; analysis code is available at an online repository as an R package. Results showed that at 450 days, the probability of in-care survival for subjects with immediate availability and enrollment was 0.93 (95% CI: 0.91, 0.95) and 0.87 (95% CI: 0.86, 0.87) for subjects with immediate availability never enrolling. For subjects without LREC availability, it was 0.91 (95% CI: 0.90, 0.92). Immediate program availability without individual enrollment, compared to no program availability, was estimated to slightly albeit significantly decrease survival by 4% (95% CI 0.03,0.06, p<0.01). Immediately availability and enrollment resulted in a 7 % higher in-care survival compared to immediate availability with non-enrollment after 450 days (95% CI-0.08,-0.05, p<0.01). The results are consistent with a fairly small impact of both availability and enrollment in the LREC program on incare survival.

Effect of HIV Antibody VRC01 on Viral Rebound after Treatment Interruption

BACKGROUND

The discovery of potent and broadly neutralizing antibodies (bNAbs) against human immunodeficiency virus (HIV) has made passive immunization a potential strategy for the prevention and treatment of HIV infection. We sought to determine whether passive administration of VRC01, a bNAb targeting the HIV CD4-binding site, can safely prevent or delay plasma viral rebound after the discontinuation of antiretroviral therapy (ART).

METHODS

We conducted two open-label trials (AIDS Clinical Trials Group [ACTG] A5340 and National Institutes of Health [NIH] 15-I-0140) of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of VRC01 in persons with HIV infection who were undergoing interruption of ART.

RESULTS

A total of 24 participants were enrolled, and one serious alcohol-related adverse event occurred. Viral rebound occurred despite plasma VRC01 concentrations greater than 50 μg per milliliter. The median time to rebound was 4 weeks in the A5340 trial and 5.6 weeks in the NIH trial. Study participants were more likely than historical controls to have viral suppression at week 4 (38% vs. 13%, P=0.04 by a two-sided Fisher's exact test in the A5340 trial; and 80% vs. 13%, P<0.001 by a two-sided Fisher's exact test in the NIH trial) but the difference was not significant at week 8. Analyses of virus populations before ART as well as before and after ART interruption showed that VRC01 exerted pressure on rebounding virus, resulting in restriction of recrudescent viruses and selection for preexisting and emerging antibody neutralization-resistant virus.

CONCLUSIONS

VRC01 slightly delayed plasma viral rebound in the trial participants, as compared with historical controls, but it did not maintain viral suppression by week 8. In the small number of participants enrolled in these trials, no safety concerns were identified with passive immunization with a single bNAb (VRC01). (Funded by the National Institute of Allergy and Infectious Diseases and others; ACTG A5340 and NIH 15-I-0140 ClinicalTrials.gov numbers, NCT02463227 and NCT02471326 .).

Past, Present, and Future Drug Delivery Systems for Antiretrovirals

The human immunodeficiency virus has infected millions of people and the epidemic continues to grow rapidly in some parts of the world. Antiretroviral (ARV) therapy has provided improved treatment and prolonged the life expectancy of patients. Moreover, there is growing interest in using ARVs to protect against new infections. Hence, ARVs have emerged as our primary strategy in combating the virus. Unfortunately, several challenges limit the optimal performance of these drugs. First, ARVs often require life-long use and complex dosing regimens. This results in low patient adherence and periods of lapsed treatment manifesting in drug resistance. This has prompted the development of alternate dosage forms such as vaginal rings and long-acting injectables that stand to improve patient adherence. Another problem central to therapeutic failure is the inadequate penetration of drugs into infected tissues. This can lead to incomplete treatment, development of resistance, and viral rebound. Several strategies have been developed to improve drug penetration into these drug-free sanctuaries. These include encapsulation of drugs in nanoparticles, use of pharmacokinetic enhancers, and cell-based drug delivery platforms. In this review, we discuss issues surrounding ARV therapy and their impact on drug efficacy. We also describe various drug delivery-based approaches developed to overcome these issues.

Differences in Activation of HIV-1 Replication by Superinfection With HIV-1 and HIV-2 in U1 Cells

Macrophages contribute to HIV-1 pathogenesis by forming a viral reservoir that serve as a viral source for the infection of CD4 T cells. The relationship between HIV-1 latent infection and superinfection in macrophages has not been well studied. Using susceptible U1 cells chronically infected with HIV-1, we studied the effects of HIV superinfection on latency and differences in superinfection with HIV-1 and HIV-2 in macrophages. We found that HIV-1 (MN) superinfection displayed increased HIV-1 replication in a time-dependent manner; while cells infected with HIV-2 (Rod) initially showed increased HIV-1 replication, followed by a decrease in HIV-1 RNA production. HIV-1 superinfection upregulated/activated NF-ĸB, NFAT, AP-1, SP-1, and MAPK Erk through expression/activation of molecules, CD4, CD3, TCRβ, Zap-70, PLCγ1, and PKCΘ in T cell receptor-related signaling pathways; while HIV-2 superinfection initially increased expression/activation of these molecules followed by decreased protein expression/activation. HIV superinfection initially downregulated HDAC1 and upregulated acetyl-histone H3 and histone H3 (K4), while HIV-2 superinfection demonstrated an increase in HDAC1 and a decrease in acetyl-histone H3 and histone H3 (K4) relative to HIV-1 superinfection. U1 cells superinfected with HIV-1 or HIV-2 showed differential expression of proteins, IL-2, PARP-1, YB-1, and LysRS. These findings indicate that superinfection with HIV-1 or HIV-2 has different effects on reactivation of HIV-1 replication. HIV-1 superinfection with high load of viral replication may result in high levels of cytotoxicity relative to HIV-2 superinfection. Cells infected with HIV-2 showed lower level of HIV-1 replication, suggesting that co-infection with HIV-2 may result in slower progression toward AIDS. J. Cell. Physiol. 232: 1746-1753, 2017. © 2016 Wiley Periodicals, Inc.

Prolonged persistence of a novel replication-defective HIV-1 variant in plasma of a patient on suppressive therapy

BACKGROUND

Cell-free residual HIV-1 virions (RVs) persist in plasma below 20-50 vRNA copies/ml in most patients on suppressive antiretroviral therapy (ART). How RVs are produced in the body during therapy is not fully clear. In this study, we have attempted to characterize these viruses of an ART-treated patient in vitro in order to gain insights into the mechanism of their production in vivo.

METHODS

We have reconstructed almost the entire genomes of RVs as DNA forms using the patient's residual plasma vRNA by an overlapping RT-nested PCR method, and then sequence-analyzed the cloned genomes and tested them for their biological activities in vitro.

RESULTS

We found that the reconstructed molecular clones of RVs lacked antiretroviral drug-resistant mutations, as well as G-to-A hypermutations. The vDNA clones, when transfected into TZM-bl cells, released HIV-p24 into the culture media at extremely low levels. This low-level virus production was found to be due to the presence of a unique mutation (GU-to-GC) in the conserved 5'-major splice donor (MSD) motif of the corresponding vRNAs. We found that the incorporation of this point mutation by itself could cause defects in the replication of a standard HIV strain (JRCSF) in vitro. However, this novel viral variant was intermittently detected at 5 of 7 time-points in the patient's plasma over a period of 39 months during therapy.

CONCLUSIONS

This is the first identification of a natural point mutation (GU-to-GC) in the conserved 5'-MSD motif of HIV genomic RNA. The intermittent but prolonged detection of this replication-defective HIV variant in the patient's plasma among other viral populations strongly suggests that this variant is released from highly stable productively infected cells present in vivo during therapy. The potential implication of this observation is that the elimination of such productively infected cells that contribute to residual viremia during suppressive therapy could be an important first step towards achieving a cure for HIV.