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Human-driven environmental changes shape ecological communities from local to global scales. Within cities, landscape-scale patterns and processes and species characteristics generally drive local-scale wildlife diversity. However, cities differ in their structure, species pools, geographies and histories, calling into question the extent to which these drivers of wildlife diversity are predictive at continental scales. In partnership with the Urban Wildlife Information Network, we used occurrence data from 725 sites located across 20 North American cities and a multi-city, multi-species occupancy modelling approach to evaluate the effects of ecoregional characteristics and mammal species traits on the urbanization-diversity relationship. Among 37 native terrestrial mammal species, regional environmental characteristics and species traits influenced within-city effects of urbanization on species occupancy and community composition. Species occupancy and diversity were most negatively related to urbanization in the warmer, less vegetated cities. Additionally, larger-bodied species were most negatively impacted by urbanization across North America. Our results suggest that shifting climate conditions could worsen the effects of urbanization on native wildlife communities, such that conservation strategies should seek to mitigate the combined effects of a warming and urbanizing world.

Purpose of Review: HIV-1 infection contributes substantially to global morbidity and mortality, with no immediate promise of an effective prophylactic vaccine. Combination antiretroviral therapy (ART) suppresses HIV replication, but latent viral reservoirs allow the virus to persist and reignite active replication if ART is discontinued. Moreover, inflammation and immune disfunction persist despite ART-mediated suppression of HIV. Immune checkpoint molecules facilitate immune dysregulation and viral persistence. However, their therapeutic modulation may offer an avenue to enhance viral immune control for patients living with HIV-1 (PLWH)., Recent Findings: The success of immune checkpoint inhibitor (ICI) therapy in oncology suggests that targeting these same immune pathways might be an effective therapeutic approach for treating PLWH. Several ICIs have been evaluated for their ability to reinvigorate exhausted T cells, and possibly reverse HIV latency, in both preclinical and clinical HIV-1 studies., Summary: Although there are very encouraging findings showing enhanced CD8 + T-cell function with ICI therapy in HIV infection, it remains uncertain whether ICIs alone could demonstrably impact the HIV reservoir. Moreover, safety concerns and significant clinical adverse events present a hurdle to the development of ICI approaches. This review provides an update on the current knowledge regarding the development of ICIs for the remission of HIV-1 in PWH. We detail recent findings from simian immunodeficiency virus (SIV)-infected rhesus macaque models, clinical trials in PLWH, and the role of soluble immune checkpoint molecules in HIV pathogenesis., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

The eradication of the viral reservoir represents the major obstacle to the development of a clinical cure for established HIV-1 infection. Here, we demonstrate that the administration of N-803 (brand name Anktiva) and broadly neutralizing antibodies (bNAbs) results in sustained viral control after discontinuation of antiretroviral therapy (ART) in simian-human AD8 (SHIV-AD8)-infected, ART-suppressed rhesus macaques. N-803+bNAbs treatment induced immune activation and transient viremia but only limited reductions in the SHIV reservoir. Upon ART discontinuation, viral rebound occurred in all animals, which was followed by durable control in approximately 70% of all N-803+bNAb-treated macaques. Viral control was correlated with the reprogramming of CD8 + T cells by N-803+bNAb synergy. Thus, complete eradication of the replication-competent viral reservoir is likely not a prerequisite for the induction of sustained remission after discontinuation of ART.

After over 3 decades of research, an effective anti-HIV vaccine remains elusive. The recently halted HVTN702 clinical trial not only further stresses the challenge to develop an effective HIV vaccine but also emphasizes that unconventional and novel vaccine strategies are urgently needed. Here, we report that a vaccine focusing the immune response on the sequences surrounding the 12 viral protease cleavage sites (PCSs) provided greater than 80% protection to Mauritian cynomolgus macaques against repeated intravaginal SIVmac251 challenges. The PCS-specific T cell responses correlated with vaccine efficacy. The PCS vaccine did not induce immune activation or inflammation known to be associated with increased susceptibility to HIV infection. Machine learning analyses revealed that the immune microenvironment generated by the PCS vaccine was predictive of vaccine efficacy. Our study demonstrates, for the first time to our knowledge, that a vaccine which targets only viral maturation, but lacks full-length Env and Gag immunogens, can prevent intravaginal infection in a stringent macaque/SIV challenge model. Targeting HIV maturation thus offers a potentially novel approach to developing an effective HIV vaccine.

In order to assess the efficacy of novel HIV-1 treatments leading to a functional cure, the time to viral rebound is frequently used as a surrogate endpoint. The longer the time to viral rebound, the more efficacious the therapy. In support of such an approach, mathematical models serve as a connection between the size of the latent reservoir and the time to HIV-1 rebound after treatment interruption. The simplest of such models assumes that a single successful latent cell reactivation event leads to observable viremia after a period of exponential viral growth. Here we consider a generalization developed by Pinkevych et al. and Hill et al. of this simple model in which multiple reactivation events can occur, each contributing to the exponential growth of the viral load. We formalize and improve the previous derivation of the dynamics predicted by this model, and use the model to estimate relevant biological parameters from SIV rebound data. We confirm a previously described effect of very early antiretroviral therapy (ART) initiation on the rate of recrudescence and the viral load growth rate after treatment interruption. We find that every day ART initiation is delayed results in a 39% increase in the recrudescence rate (95% credible interval: [18%, 62%]), and a 11% decrease of the viral growth rate (95% credible interval: [4%, 20%]). We show that when viral rebound occurs early relative to the viral load doubling time, a model with multiple successful reactivation events fits the data better than a model with only a single successful reactivation event., Competing Interests: The authors have declared that no competing interests exist.

Studies have shown that vaccine vectors and route of immunization can differentially activate different arms of the immune system. However, the effects of different HIV vaccine immunogens on mucosal inflammation have not yet been studied. Because mucosal sites are the primary route of HIV infection, we evaluated the cervico-vaginal inflammatory cytokine and chemokine levels of Mauritian cynomolgus macaques following immunization and boost using two different SIV vaccine immunogens. The PCS vaccine delivers 12 20-amino acid peptides overlapping the 12 protease cleavage sites, and the Gag/Env vaccine delivers the full Gag and full Env proteins of simian immunodeficiency virus. We showed that the PCS vaccine prime and boosts induced short-lived, lower level increases of a few pro-inflammatory/chemotactic cytokines. In the PCS-vaccine group only the levels of MCP-1 were significantly increased above the baseline ( P = 0.0078, Week 6; P = 0.0078, Week 17; P = 0.0234; Week 51) following multiple boosts. In contrast, immunizations with the Gag/Env vaccine persistently increased the levels of multiple cytokines/chemokines. In the Gag/Env group, higher than baseline levels were consistently observed for IL-8 ( P = 0.0078, Week 16; P = 0.0078, Week 17; P = 0.0156, Week 52), IL-1β ( P = 0.0234, Week 16; P = 0.0156, Week 17; P = 0.0156, Week 52), and MIP-1α ( P = 0.0313, Week 16; P = 0.0156, Week 17; P = 0.0313, Week 52). Over time, repeated boosts altered the relative levels of these cytokines between the Gag/Env and PCS vaccine group. 18 weeks after final boost with a higher dosage, IP-10 levels ( P = 0.0313) in the Gag/Env group remained higher than baseline. Thus, the influence of vaccine immunogens on mucosal inflammation needs to be considered when developing and evaluating candidate HIV vaccines., (Copyright © 2020 Toledo, Li, Omange, Dacoba, Crecente-Campo, Schalk, Kashem, Rakasz, Schultz-Darken, Li, Whitney, Alonso, Plummer and Luo.)

Zika virus infection in humans has been associated with serious reproductive and neurological complications. At present, no protective antiviral drug treatment is available. Here, we describe the testing and evaluation of the antiviral drug, galidesivir, against Zika virus infection in rhesus macaques. We conducted four preclinical studies in rhesus macaques to assess the safety, antiviral efficacy, and dosing strategies for galidesivir (BCX4430) against Zika virus infection. We treated 70 rhesus macaques infected by various routes with the Puerto Rico or Thai Zika virus isolates. We evaluated galidesivir administered as early as 90 min and as late as 72 hours after subcutaneous Zika virus infection and as late as 5 days after intravaginal infection. We evaluated the efficacy of a range of galidesivir doses with endpoints including Zika virus RNA in plasma, saliva, urine, and cerebrospinal fluid. Galidesivir dosing in rhesus macaques was safe and offered postexposure protection against Zika virus infection. Galidesivir exhibited favorable pharmacokinetics with no observed teratogenic effects in rats or rabbits at any dose tested. The antiviral efficacy of galidesivir observed in the blood and central nervous system of infected animals warrants continued evaluation of this compound for the treatment of flaviviral infections., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Human immunodeficiency virus (HIV) infection is characterized by a massive loss of CD4 T cells in the gastrointestinal tract (GIT) that is accompanied by changes in the gut microbiome and microbial translocation that contribute to inflammation and chronic immune activation. Though highly active antiretroviral therapy (HAART) has led to better long-term outcomes in HIV infected patients, it has not been as effective at reverting pathogenesis in the GIT. Using the simian immunodeficiency virus (SIV) infection model, we show that combination antiretroviral therapy (c-ART) partially reverted microbial dysbiosis observed during SIV infection. Though the relative abundance of bacteria, their richness or diversity did not significantly differ between infected and treated animals, microbial dysbiosis was evident via multiple beta diversity metrics: Jaccard similarity coefficient, Bray-Curtis similarity coefficient, and Yue & Clayton theta similarity coefficient. Principal coordinates analysis (PCoA) clustered SIV-infected untreated animals away from healthy and treated animals that were clustered closely, indicating that c-ART partially reversed the gut dysbiosis associated with SIV infection. Metastats analysis identified specific operational taxonomic units (OTUs) falling within the Streptococcus, Prevotella, Acinetobacter, Treponema, and Lactobacillus genera that were differentially represented across the three groups. Our results suggest that complete viral suppression with c-ART could potentially revert microbial dysbiosis observed during SIV and HIV infections.

The clinical application of a PGT-A program implementing single euploid embryo transfer is evaluated over a 6.5 year period, beginning with its early validation phases. Euploidy embryo status is inversely correlated to oocyte source age and positively correlated to blastocyst quality grades. However, once a single euploid embryo is transferred, high levels of implantation and live birth success are attained independent of patient age and embryo quality, with only AA blastocysts exhibiting improved implantation. Factors influencing successful outcomes are discussed, including the management of mosaic NGS profiles. Overall, distinct advantages to a dedicated PGT-A/single euploid embryo transfer program are clearly evident in per cycle start comparisons to control cycles and national average statistics by age groups., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Objective: To determine if Day 7 blastocysts merit biopsy, vitrification and transfer consideration by contrasting their aneuploidy and implantation rates to Day 5 and 6 blastocysts., Methods: A total of 1,925 blastocysts were biopsied from 402 PGT-A cycles over a 12 to 16 month interval. All embryos were cultured under tri-gas, humidified conditions (37ºC) for up to 7 days (168 hours post-insemination). Biopsied blastocysts were vitrified and trophectoderm samples analyzed using NextGen sequencing. Single euploid embryo transfers were performed (n=254) using either a Day 5 (n=145), Day 6 (n=92) or a Day 7 blastocyst (n=16) post-warming. Euploidy rates and pregnancy outcomes were subsequently assessed and differences determined by day of development and blastocyst quality grade., Results: No differences were observed in implantation, pregnancy loss or ongoing pregnancy rates between Day 5 and Day 6 blastocysts. Development to Day 7 accounted for 6.6% of all blastocysts. Euploidy rates were higher in Day 5 blastocysts (53.5%; p <0.05) compared to Day 6 (40.4%) and Day 7 (35.9%). High implantation potential (56.3% to 79.3%) of vitrified-warmed euploid blastocyst occurred independent to the day of development. However, miscarriage/loss rates increased (22.2% vs. 2%; p <0.05) with Day 7 blastocysts, resulting in lower ( p <0.05) live birth rates (43.8% vs. 67.4-77.2%)., Conclusion: Culturing blastocysts to Day 7 has proven beneficial by achieving viable euploid embryos that would have otherwise been discarded. An extra Day of embryo growth allows select patients additional opportunities for in vitro development and possible healthy term live births.

Recent publicized events of cryogenic storage tank failures have created nationwide concern among infertility patients and patients storing embryos and gametes for future use. To assure patient confidence, quality management (QM) plans applied by in vitro fertilization (IVF) laboratories need to include a more comprehensive focus on the cryostorage of reproductive specimens. The purpose of this review is to provide best practice guidelines for the cryogenic storage of sperm, oocytes, embryos, and other reproductive tissues (e.g., testicular and ovarian tissue, cord blood cells, and stem cells) and recommend a strategy of thorough and appropriate quality and risk management procedures aimed to alleviate or minimize the consequences from catastrophic events.

The precise time when the viral reservoir is seeded during acute HIV-1 infection remains unclear. We previously demonstrated that the viral reservoir was seeded by day 3 following SIVmac251 infection in rhesus monkeys. Here we report the impact of initiating ART on day 0 (6 h), 1, 2, or 3 following intrarectal SIVmac251 infection in 20 rhesus monkeys (N = 5/group). After 6 months of daily suppressive ART, antiretroviral drugs were discontinued, and viral rebound was monitored. 0% (0 of 5), 20% (1 of 5), 60% (3 of 5), and 100% (5 of 5) of animals that initiated ART on days 0 (6 h), 1, 2, or 3, respectively, showed viral rebound following ART discontinuation and correlated with integrated viral DNA in lymph node CD4+ T cells. These data demonstrate that the viral reservoir is seeded within the first few days of infection and that early ART initiation limits the viral reservoir.

Antiretroviral therapy (ART) for the treatment of human immunodeficiency virus (HIV) infection represents a major breakthrough in the treatment of HIV/acquired immune-deficiency syndrome. However, it remains unclear how ART influences virus-specific immune responses and understanding this is important for developing novel cure and eradication interventions for HIV-1. In the present study, we evaluate how ART impacts T-cell and antibody responses in simian immunodeficiency virus (SIV) -infected rhesus macaques. We evaluated CD4 and CD8 T-cell responses by multiparameter flow cytometry, viral loads by quantitative RT-PCR by a two-step process using SIV-specific primers and antibody neutralization function by luciferase-based TZM-bl assays. We demonstrate that macaques treated with ART exhibit phenotypic and qualitative effects on T-cell and antibody responses. Macaques on ART exhibited low numbers of virus-specific T-cell responses, and these responses appeared to be partially biased towards central memory subsets. More importantly, there were significantly reduced neutralizing antibody responses in macaques treated with ART. Collectively, these data improve the understanding of how virus-specific immune responses are generated during ART, and suggest the potential importance of therapeutic vaccines to maintain adaptive immunity during treated infection., (© 2018 John Wiley & Sons Ltd.)

In this Brief Communications Arising Comment, the first three authors (Osuna, Lim and Kublin) should have been listed as equally contributing authors; this has been corrected online.

HIV mutates rapidly and infects CD4+ T cells, especially when they are activated. A vaccine targeting conserved, essential viral elements while limiting CD4+ T cell activation could be effective. Learning from natural immunity observed in a group of highly HIV-1 exposed seronegative Kenyan female sex workers, we are testing a novel candidate HIV vaccine targeting the 12 viral protease cleavage sites (PCSs) (the PCS vaccine), in comparison with a vaccine targeting full-length Gag and Env (the Gag/Env vaccine) in a Mauritian cynomolgus macaque/SIV model. In this study we evaluated these vaccines for induction of mucosal antibodies to SIV immunogens at the female genital tract. Bio-Plex and Western blot analyses of cervicovaginal lavage samples showed that both the PCS and Gag/Env vaccines can elicit mucosal IgG antibody responses to SIV immunogens. Significantly higher increase of anti-PCS antibodies was induced by the PCS vaccine than by the Gag/Env vaccine (p<0.0001). The effect of the mucosal antibody responses in protection from repeated low dose pathogenic SIVmac251 challenges is being evaluated., Competing Interests: The authors have declared that no competing interests exist.

The 2015 Brazilian Zika virus outbreak sparked a rapid response to control the spread of the virus. What was first understood to be a mild self-resolving infection is now linked to significant neurological defects in both neonates and adults. The WHO declared the 2016 Zika epidemic a public health emergency and issued an unprecedented recommendation to women in affected regions to delay pregnancy until the risks surrounding Zika virus could be understood, or the epidemic contained. Since that time, considerable effort has been dedicated to understanding Zika transmission and pathogenesis to aid the development of drugs and vaccines. Several models have emerged to study numerous facets of Zika biology; this review details the various model systems., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Antiretroviral therapy (ART) can halt HIV-1 replication but fails to target the long-lived latent viral reservoir. Several pharmacological compounds have been evaluated for their ability to reverse HIV-1 latency, but none has demonstrably reduced the latent HIV-1 reservoir or affected viral rebound after the interruption of ART. We evaluated orally administered selective Toll-like receptor 7 (TLR7) agonists GS-986 and GS-9620 for their ability to induce transient viremia in rhesus macaques infected with simian immunodeficiency virus (SIV) and treated with suppressive ART. In an initial dose-escalation study, and a subsequent dose-optimization study, we found that TLR7 agonists activated multiple innate and adaptive immune cell populations in addition to inducing expression of SIV RNA. We also observed TLR7 agonist-induced reductions in SIV DNA and measured inducible virus from treated animals in ex vivo cell cultures. In a second study, after stopping ART, two of nine treated animals remained aviremic for more than 2 years, even after in vivo CD8 + T cell depletion. Moreover, adoptive transfer of cells from aviremic animals could not induce de novo infection in naïve recipient macaques. These findings suggest that TLR7 agonists may facilitate reduction of the viral reservoir in a subset of SIV-infected rhesus macaques., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Sequestering of latent HIV in follicular helper T cells within B-cell follicles that largely exclude cytotoxic T cells is a major barrier to cellular immune-based approaches to eradicate HIV. Here, we show that the clinical-grade human interleukin-15 (IL-15) superagonist ALT-803 activates and redirects simian immunodeficiency virus (SIV)-specific CD8 + T cells from the peripheral blood into B-cell follicles. In agreement with the increased trafficking of SIV-specific cytotoxic T cells to sites of cryptic viral replication, lymph nodes of elite controlling macaques contained fewer cells expressing SIV RNA or harboring SIV DNA post-ALT-803 treatment. These data establish ALT-803 as an immunotherapeutic for HIV and other chronic viral pathogens that evade host immunity by persisting in B-cell follicles., (© 2018 by The American Society of Hematology.)

Latently infected cells are very infrequent in CD4+ T cells from antiretroviral (ARV) treated individuals, with only approximately one in a million infected CD4+ T cells in blood. Given the low frequency of infected cells in vivo, multiple in vitro latency models have been developed to facilitate investigations into mechanisms of HIV latency, as well as to enable the evaluation of pharmacological and immunological interventions aimed at depleting latently infected cells. These in vitro models include clones of transformed cell lines with integrated HIV proviruses or primary CD4+ T cells from uninfected donors that have been infected with HIV in particular conditions. This chapter presents a description of these various in vitro models, along with an overview of their advantages and limitations.Preclinical animal models represent a critical bridge between in vitro studies and human clinical trials. Simian immunodeficiency virus (SIV) infection of Indian origin rhesus macaques has been well established as an informative model of HIV infection. Recent years have seen breakthroughs in ARVs that permit the potent suppression of SIV replication, enabling studies of latency and putative curative interventions in this model. Small animal models of HIV infection can be generated by engrafting immunodeficient mice with human immune cells. These "humanized mice" have provided valuable insights into HIV pathogenesis and are under development as models for studying HIV latency. We summarize both the promise of these models and outstanding challenges that remain to be overcome to realize their potential to inform efforts to cure HIV infection.

Zika virus is a re-emerging flavivirus transmitted primarily by arthropod vectors. The recent devastating outbreak of Zika virus in Brazil was preceded by the slow global encroachment of this virus over many decades. To date, significant research efforts are underway to understand the spread and the unique pathogenesis of this virus; with the intent to rapidly develop vaccines and therapeutics. Several model systems have emerged to study Zika. This review will focus on the use of nonhuman primates to model Zika infection., (© The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Cynomolgus macaques are an increasingly important nonhuman primate model for HIV vaccine research. SIV-free animals without pre-existing anti-SIV immune responses are generally needed to evaluate the effect of vaccine-induced immune responses against the vaccine epitopes. Here, in order to select such animals for vaccine studies, we screened 108 naïve female Mauritian cynomolgus macaques for natural (baseline) antibodies to SIV antigens using a Bio-Plex multiplex system. The antigens included twelve 20mer peptides overlapping the twelve SIV protease cleavage sites (-10/+10), respectively (PCS peptides), and three non-PCS Gag or Env peptides. Natural antibodies to SIV antigens were detected in subsets of monkeys. The antibody reactivity to SIV was further confirmed by Western blot using purified recombinant SIV Gag and Env proteins. As expected, the immunization of monkeys with PCS antigens elicited anti-PCS antibodies. However, unexpectedly, antibodies to non-PCS peptides were also induced, as shown by both Bio-Plex and Western blot analyses, while the non-PCS peptides do not share sequence homology with PCS peptides. The presence of natural and vaccine cross-inducible SIV antibodies in Mauritian cynomolgus macaques should be considered in animal selection, experimental design and result interpretation, for their best use in HIV vaccine research.

HIV-1 sequence diversity presents a major challenge for the clinical development of broadly neutralizing antibodies (bNAbs) for both therapy and prevention. Sequence variation in critical bNAb epitopes has been observed in most HIV-1-infected individuals and can lead to viral escape after bNAb monotherapy in humans. We show that viral sequence diversity can limit both the therapeutic and prophylactic efficacy of bNAbs in rhesus monkeys. We first demonstrate that monotherapy with the V3 glycan-dependent antibody 10-1074, but not PGT121, results in rapid selection of preexisting viral variants containing N332/S334 escape mutations and loss of therapeutic efficacy in simian-HIV (SHIV)-SF162P3-infected rhesus monkeys. We then show that the V3 glycan-dependent antibody PGT121 alone and the V2 glycan-dependent antibody PGDM1400 alone both fail to protect against a mixed challenge with SHIV-SF162P3 and SHIV-325c. In contrast, the combination of both bNAbs provides 100% protection against this mixed SHIV challenge. These data reveal that single bNAbs efficiently select resistant viruses from a diverse challenge swarm to establish infection, demonstrating the importance of bNAb cocktails for HIV-1 prevention., (Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The recent outbreak of Zika virus (ZIKV) has been associated with fetal abnormalities and neurological complications, prompting global concern. Here we present a mathematical analysis of the within-host dynamics of plasma ZIKV burden in a nonhuman primate model, allowing for characterization of the growth and clearance of ZIKV within individual macaques. We estimate that the eclipse phase for ZIKV, the time between cell infection and viral production, is most likely short (∼4 h), the median within-host basic reproductive number R 0 is 10.7, the rate of viral production is rapid (>25,000 virions d -1 ), and the lifetime of an infected cell while producing virus is ∼5 h. We also estimate that the minimum number of virions produced by an infected cell over its lifetime is ∼5,500. We assess the potential effect of an antiviral treatment that blocks viral replication, showing that the median time to undetectable plasma viral load (VL) can be reduced from ∼5 d to ∼3 d with a drug concentration ∼15 times the drug's EC 50 when treatment is given prophylactically starting at the time of infection. In the case of favipiravir, a polymerase inhibitor with activity against ZIKV, we predict a dose of 150 mg/kg given twice a day initiated at the time of infection can reduce the peak median VL by ∼3 logs and shorten the time to undetectable median VL by ∼2 d, whereas treatment given 2 d postinfection is mostly ineffective in accelerating plasma VL loss in macaques., Competing Interests: The authors declare no conflict of interest.

Background: Understanding natural HIV control may lead to new preventative or therapeutic strategies. Several protective major histocompatibility complex (MHC) genotypes were found in humans and rhesus macaques. Here, we report a simian immunodeficiency virus (SIV) controller MHC genotype in Mauritian cynomolgus macaques (MCMs)., Methods: Twelve MHC-genotyped MCMs were infected with SIVmac251 and monitored for viral loads and CD4+ T-cell counts., Results: Two macaques with M3M4 genotype exhibited the lowest peak viral loads (log plasma SIV RNA copies/mL), nearly 3 logs lower than those in most macaques with other MHC haplotype combinations, and set point viral loads below the level of detection limit by RT-qPCR (<2 log RNA copies/mL). They maintained healthy CD4+ T-cell counts of >500 cells/μL blood, while CD4 counts in the vast majority of other macaques were below this level., Conclusions: The M3M4 MHC genotype may confer enhanced control of SIV replication in MCMs., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Clinical embryo vitrification evolved with the development of unique vitrification devices in the 21 st century and with the misconception that ultra-rapid cooling in an "open" system (i.e., direct LN2 contact) was a necessity to optimize vitrification success. The dogma surrounding the importance of cooling rates led to unsafe practices subject to technical variation and to the creation of vitrification devices that disregarded important quality-control factors (e.g., ease of use, repeatability, reliability, labeling security, and storage safety). Understanding the quality-control flaws of other devices allowed for the development of a safe, secure, repeatable, and reliable µS-VTF method aimed to minimize intra- and inter-technician variation. Equally important, it combined the availability of two existing FDA-compliant devices: 1) a 0.3-mL ionomeric resin embryo straw with internalized, dual-colored, tamper-proof labeling with repeatable weld seal potential; and 2) shortened, commonly-used, 300-µm ID sterile flexipettes to directly load the embryo(s) in order to create a highly-effective global vitrification device. Like other aseptic, closed vitrification systems (e.g., High Security Vitrification (HSV), Rapid-i, and VitriSafe) effectively used in reproductive medicine, microSecure Vitrification (µS-VTF) has proven that it can achieve high post-warming survival and pregnancy outcomes with its attention to simplicity, and reduced technical variation. Although the 0.3-mL embryo straw containing an internal hydrophobic plug was commercially replaced with a standard semen straw possessing cotton-polyvinyl pyrrolidone (PVP) plugs, it maintained its ionomeric resin composition to ensure weld sealing. However, the cotton plugs can wick out the fluid-embryo contents of the flexipettes upon contact. A modified µS-VTF method was adapted to include an additional internal weld seal before the plug on the device loading side. The added technical step to the µS-VTF procedure has not affected its successful application, as high survival rates (> 95%) and pregnancy rates continue today.

Infection with Zika virus has been associated with serious neurological complications and fetal abnormalities. However, the dynamics of viral infection, replication and shedding are poorly understood. Here we show that both rhesus and cynomolgus macaques are highly susceptible to infection by lineages of Zika virus that are closely related to, or are currently circulating in, the Americas. After subcutaneous viral inoculation, viral RNA was detected in blood plasma as early as 1 d after infection. Viral RNA was also detected in saliva, urine, cerebrospinal fluid (CSF) and semen, but transiently in vaginal secretions. Although viral RNA during primary infection was cleared from blood plasma and urine within 10 d, viral RNA was detectable in saliva and seminal fluids until the end of the study, 3 weeks after the resolution of viremia in the blood. The control of primary Zika virus infection in the blood was correlated with rapid innate and adaptive immune responses. We also identified Zika RNA in tissues, including the brain and male and female reproductive tissues, during early and late stages of infection. Re-infection of six animals 45 d after primary infection with a heterologous strain resulted in complete protection, which suggests that primary Zika virus infection elicits protective immunity. Early invasion of Zika virus into the nervous system of healthy animals and the extent and duration of shedding in saliva and semen underscore possible concern for additional neurologic complications and nonarthropod-mediated transmission in humans., Competing Interests: The authors declare no competing financial interests.

Purpose: The study aims to contrast the efficacy of trophectoderm biopsy preimplantation genetic screening (PGS)/vitrification (VTF)-all cycles to past treatment protocols. Specifically, do these applied technologies increase live birth rates on a per cycle/first transfer basis?, Materials and Methods: An observational, retrospective cohort study of first transfer outcomes was performed in two groups. Group 1 (PGS) included PGS/VTF-all cycles, and group 2 (no PGS) included the first transfer from non-PGS fresh cycles or VTF-ALL cycles. In group 1, all blastocysts were biopsied on days 5/6, vitrified and array CGH performed. Group 2 patients had embryo transfers on day 3 or day 5. All blastocysts were vitrified and warmed according to μS-VTF protocols. Clinical pregnancies and implantation were confirmed by ultrasound and live birth information attained. Results were stratified by age with donor cycles excluded, and to eliminate bias, the same groups were then validated on a per cycle basis. Chi-squared used to determine significance., Results: Analyzing 287 embryo transfers and 1,000+ PGS-tested blastocysts, an overall 97 % increase in live births favored group 1 (PGS). When utilizing PGS/VTF-ALL cycles, patients under 43 years old exhibited higher implantation, clinical pregnancy, and ongoing/live birth rates. Re-analyzing the data to include all cycles initiated revealed higher live birth rates in group 1 age groups ≤34 and 38-40 years old., Conclusion: Validating PGS on a per cycle basis eliminated data bias by including patients without blastocysts to biopsy or euploid embryos. Clearly, PGS uses blastocysts more efficiently to achieve success, while many women over 40 may benefit most by understanding why some failures occur., Support: None., Competing Interests: Compliance with ethical standard Conflict of interest The authors declare that they have no conflict of interest.

Objective: Passive administration of broadly neutralizing antibodies has been shown to protect against both vaginal and rectal challenge in the simian/human immunodeficiency virus (SHIV)/macaque model of HIV transmission. However, the relative efficacy of antibody against the two modes of exposure is unknown and, given differences in the composition and immunology of the two tissue compartments, this is an important gap in knowledge. To investigate the significance of the challenge route for antibody-mediated protection, we performed a comparative protection study in macaques using the highly potent human monoclonal antibody, PGT126., Design: Animals were administered PGT126 at three different doses before challenged either vaginally or rectally with a single dose of SHIVSF163P3., Methods: Viral loads, PGT126 serum concentrations, and serum neutralizing titers were monitored., Results: In vaginally challenged animals, sterilizing immunity was achieved in all animals administered 10 mg/kg, in two of five animals administered 2 mg/kg and in one of five animals administered 0.4 mg/kg PGT126. Comparable protection was observed for the corresponding groups challenged rectally as sterilizing immunity was achieved in three of four animals administered 10 mg/kg, in two of four animals administered 2 mg/kg and in none of four animals administered 0.4 mg/kg PGT126. Serological analysis showed similar serum concentrations of PGT126 and serum neutralization titers in animals administered the same antibody dose., Conclusion: Our data suggest that broadly neutralizing antibody-mediated protection is not strongly dependent on the mucosal route of challenge, which indicates that a vaccine aimed to induce a neutralizing antibody response would have broadly similar efficacy against both primary transmission routes for HIV.

Resting CD4+ T-cells harboring inducible HIV proviruses are a critical reservoir in antiretroviral therapy (ART)-treated subjects. These cells express little to no viral protein, and thus neither die by viral cytopathic effects, nor are efficiently cleared by immune effectors. Elimination of this reservoir is theoretically possible by combining latency-reversing agents (LRAs) with immune effectors, such as CD8+ T-cells. However, the relative efficacy of different LRAs in sensitizing latently-infected cells for recognition by HIV-specific CD8+ T-cells has not been determined. To address this, we developed an assay that utilizes HIV-specific CD8+ T-cell clones as biosensors for HIV antigen expression. By testing multiple CD8+ T-cell clones against a primary cell model of HIV latency, we identified several single agents that primed latently-infected cells for CD8+ T-cell recognition, including IL-2, IL-15, two IL-15 superagonists (IL-15SA and ALT-803), prostratin, and the TLR-2 ligand Pam3CSK4. In contrast, we did not observe CD8+ T-cell recognition of target cells following treatment with histone deacetylase inhibitors or with hexamethylene bisacetamide (HMBA). In further experiments we demonstrate that a clinically achievable concentration of the IL-15 superagonist 'ALT-803', an agent presently in clinical trials for solid and hematological tumors, primes the natural ex vivo reservoir for CD8+ T-cell recognition. Thus, our results establish a novel experimental approach for comparative evaluation of LRAs, and highlight ALT-803 as an LRA with the potential to synergize with CD8+ T-cells in HIV eradication strategies.

Simian-human immunodeficiency virus (SHIV) challenge stocks are critical for preclinical testing of vaccines, antibodies, and other interventions aimed to prevent HIV-1. A major unmet need for the field has been the lack of a SHIV challenge stock expressing circulating recombinant form 01&#95;AE (CRF01&#95;AE) env sequences. We therefore sought to develop mucosally transmissible SHIV challenge stocks containing HIV-1 CRF01&#95;AE env derived from acutely HIV-1 infected individuals from Thailand. SHIV-AE6, SHIV-AE6RM, and SHIV-AE16 contained env sequences that were >99% identical to the original HIV-1 isolate and did not require in vivo passaging. These viruses exhibited CCR5 tropism and displayed a tier 2 neutralization phenotype. These challenge stocks efficiently infected rhesus monkeys by the intrarectal route, replicated to high levels during acute infection, and established chronic viremia in a subset of animals. SHIV-AE16 was titrated for use in single, high dose as well as repetitive, low dose intrarectal challenge studies. These SHIV challenge stocks should facilitate the preclinical evaluation of vaccines, monoclonal antibodies, and other interventions targeted at preventing HIV-1 CRF01&#95;AE infection.

Preclinical studies of viral vector-based HIV-1 vaccine candidates have previously shown partial protection against neutralization-resistant virus challenges in rhesus monkeys. In this study, we evaluated the protective efficacy of adenovirus serotype 26 (Ad26) vector priming followed by purified envelope (Env) glycoprotein boosting. Rhesus monkeys primed with Ad26 vectors expressing SIVsmE543 Env, Gag, and Pol and boosted with AS01B-adjuvanted SIVmac32H Env gp140 demonstrated complete protection in 50% of vaccinated animals against a series of repeated, heterologous, intrarectal SIVmac251 challenges that infected all controls. Protective efficacy correlated with the functionality of Env-specific antibody responses. Comparable protection was also observed with a similar Ad/Env vaccine against repeated, heterologous, intrarectal SHIV-SF162P3 challenges. These data demonstrate robust protection by Ad/Env vaccines against acquisition of neutralization-resistant virus challenges in rhesus monkeys., (Copyright © 2015, American Association for the Advancement of Science.)

Unlabelled: The development of a panel of mucosally transmissible simian-human immunodeficiency virus (SHIV) challenge stocks from multiple virus clades would facilitate preclinical evaluation of candidate HIV-1 vaccines and therapeutics. The majority of SHIV stocks that have been generated to date have been derived from clade B HIV-1 env sequences from viruses isolated during chronic infection and typically required serial animal-to-animal adaptation for establishing mucosal transmissibility and pathogenicity. To capture essential features of mucosal transmission of clade C viruses, we produced a series of SHIVs with early clade C HIV-1 env sequences from acutely HIV-1-infected individuals from South Africa. SHIV-327c and SHIV-327cRM expressed env sequences that were 99.7 to 100% identical to the original HIV-1 isolate and did not require in vivo passaging for mucosal infectivity. These challenge stocks infected rhesus monkeys efficiently by both intrarectal and intravaginal routes, replicated to high levels during acute infection, and established chronic setpoint viremia in 13 of 17 (76%) infected animals. The SHIV-327cRM challenge stock was also titrated for both single, high-dose intrarectal challenges and repetitive, low-dose intrarectal challenges in rhesus monkeys. These SHIV challenge stocks should facilitate the preclinical evaluation of vaccines and other interventions aimed at preventing clade C HIV-1 infection., Importance: We describe the development of two related clade C SHIV challenge stocks. These challenge stocks should prove useful for preclinical testing of vaccines and other interventions aimed at preventing clade C HIV-1 infection., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Objective: To document the risk of in vitro monochorionic dizygotic twin formation in the implementation of a program of blastocyst biopsy with preimplantation genetic screening (PGS)., Design: Case report., Setting: Private infertility laboratory., Patient(s): Prospective PGS patients with intracytoplasmic sperm injection-derived, group-cultured blastocysts over a 3-year period., Intervention(s): Group culture in Global medium (Life Global) to optimize blastocyst formation of zygotes produced for blastocyst biopsy for PGS (n ≤ 8 embryos/25 μL droplet), and laser zona dissection (LZD) of all day-3 cleaved embryos to promote pre-expansion trophectodermal extrusion at the blastocyst stage (i.e., premature hatching)., Main Outcome Measure(s): Blastocyst formation and quality grading on days 5 and 6 of in vitro culture for the vitrified embryo transfer of single or dual euploid blastocysts., Result(s): Over 3,000 blastocysts were produced in vitro. On two separate occasions, complete trophectodermal amalgamation was observed between two hatching blastocysts. Vitrified single-euploid blastocyst transfers efficiently implanted and established clinical pregnancies similar to dual-euploid blastocyst transfers, without the risk of twin formation., Conclusion(s): The amazing occurrence of monochorionic dizygotic twin formation has now been documented in vitro, supporting the theory that assisted reproductive technology may facilitate this rare perinatal condition. Furthermore, we have provided clinical evidence that the transfer of a single-euploid blastocyst can optimize a patient's pregnancy success while reducing potentially undesirable conditions associated with monochorionic twin pregnancies., (Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

The viral reservoir represents a critical challenge for human immunodeficiency virus type 1 (HIV-1) eradication strategies. However, it remains unclear when and where the viral reservoir is seeded during acute infection and the extent to which it is susceptible to early antiretroviral therapy (ART). Here we show that the viral reservoir is seeded rapidly after mucosal simian immunodeficiency virus (SIV) infection of rhesus monkeys and before systemic viraemia. We initiated suppressive ART in groups of monkeys on days 3, 7, 10 and 14 after intrarectal SIVMAC251 infection. Treatment with ART on day 3 blocked the emergence of viral RNA and proviral DNA in peripheral blood and also substantially reduced levels of proviral DNA in lymph nodes and gastrointestinal mucosa as compared with treatment at later time points. In addition, treatment on day 3 abrogated the induction of SIV-specific humoral and cellular immune responses. Nevertheless, after discontinuation of ART following 24 weeks of fully suppressive therapy, virus rebounded in all animals, although the monkeys that were treated on day 3 exhibited a delayed viral rebound as compared with those treated on days 7, 10 and 14. The time to viral rebound correlated with total viraemia during acute infection and with proviral DNA at the time of ART discontinuation. These data demonstrate that the viral reservoir is seeded rapidly after intrarectal SIV infection of rhesus monkeys, during the 'eclipse' phase, and before detectable viraemia. This strikingly early seeding of the refractory viral reservoir raises important new challenges for HIV-1 eradication strategies.

Human immunodeficiency virus type 1 (HIV-1)-specific monoclonal antibodies with extraordinary potency and breadth have recently been described. In humanized mice, combinations of monoclonal antibodies have been shown to suppress viraemia, but the therapeutic potential of these monoclonal antibodies has not yet been evaluated in primates with an intact immune system. Here we show that administration of a cocktail of HIV-1-specific monoclonal antibodies, as well as the single glycan-dependent monoclonal antibody PGT121, resulted in a rapid and precipitous decline of plasma viraemia to undetectable levels in rhesus monkeys chronically infected with the pathogenic simian-human immunodeficiency virus SHIV-SF162P3. A single monoclonal antibody infusion afforded up to a 3.1 log decline of plasma viral RNA in 7 days and also reduced proviral DNA in peripheral blood, gastrointestinal mucosa and lymph nodes without the development of viral resistance. Moreover, after monoclonal antibody administration, host Gag-specific T-lymphocyte responses showed improved functionality. Virus rebounded in most animals after a median of 56 days when serum monoclonal antibody titres had declined to undetectable levels, although, notably, a subset of animals maintained long-term virological control in the absence of further monoclonal antibody infusions. These data demonstrate a profound therapeutic effect of potent neutralizing HIV-1-specific monoclonal antibodies in SHIV-infected rhesus monkeys as well as an impact on host immune responses. Our findings strongly encourage the investigation of monoclonal antibody therapy for HIV-1 in humans.

Endogenous serine protease inhibitors (serpins) are anti-inflammatory mediators with multiple biologic functions. Several serpins have been reported to modulate HIV pathogenesis, or exhibit potent anti-HIV activity in vitro, but the efficacy of serpins as therapeutic agents for HIV in vivo has not yet been demonstrated. In the present study, we show that heparin-activated antithrombin III (hep-ATIII), a member of the serpin family, significantly inhibits lentiviral replication in a non-human primate model. We further demonstrate greater than one log(10) reduction in plasma viremia in the nonhuman primate system by loading of hep-ATIII into anti-HLA-DR immunoliposomes, which target tissue reservoirs of viral replication. We also demonstrate the utility of hep-ATIIII as a potential salvage agent for HIV strains resistant to standard anti-retroviral treatment. Finally, we applied gene-expression arrays to analyze hep-ATIII-induced host cell interactomes and found that downstream of hep-ATIII, two independent gene networks were modulated by host factors prostaglandin synthetase-2, ERK1/2 and NFκB. Ultimately, understanding how serpins, such as hep-ATIII, regulate host responses during HIV infection may reveal new avenues for therapeutic intervention.

Retroviruses are known to exhibit remarkable genomic pliancy, a capacity that has been attributed to one or more error prone steps in the viral replication cycle. However, increasing evidence suggests that such error represents a key element in viral survival, as exemplified by studies on virus immune evasion, shifts of cellular tropism, and anatomic compartmentalization, which facilitate persistent virus reservoirs. Understanding the dynamic mechanisms that contribute to the establishment and maintenance of retroviral persistence is critical toward the goal of attaining HIV-1 eradication.

There is considerable variability in host susceptibility to human immunodeficiency virus type 1 (HIV-1) infection, but the host genetic determinants of that variability are not well understood. In addition to serving as a block for cross-species retroviral infection, TRIM5 was recently shown to play a central role in limiting primate immunodeficiency virus replication. We hypothesized that TRIM5 may also contribute to susceptibility to mucosal acquisition of simian immunodeficiency virus (SIV) in rhesus monkeys. We explored this hypothesis by establishing 3 cohorts of Indian-origin rhesus monkeys with different TRIM5 genotypes: homozygous restrictive, heterozygous permissive, and homozygous permissive. We then evaluated the effect of TRIM5 genotype on the penile transmission of SIVsmE660. We observed a significant effect of TRIM5 genotype on mucosal SIVsmE660 acquisition in that no SIV transmission occurred in monkeys with only restrictive TRIM5 alleles. In contrast, systemic SIV infections were initiated after preputial pocket exposures in monkeys that had at least one permissive TRIM5 allele. These data demonstrate that host genetic factors can play a critical role in restricting mucosal transmission of a primate immunodeficiency virus. In addition, we used our understanding of TRIM5 to establish a novel nonhuman primate penile transmission model for AIDS mucosal pathogenesis and vaccine research.

The RV144 vaccine trial in Thailand demonstrated that an HIV vaccine could prevent infection in humans and highlights the importance of understanding protective immunity against HIV. We used a nonhuman primate model to define immune and genetic mechanisms of protection against mucosal infection by the simian immunodeficiency virus (SIV). A plasmid DNA prime/recombinant adenovirus serotype 5 (rAd5) boost vaccine regimen was evaluated for its ability to protect monkeys from infection by SIVmac251 or SIVsmE660 isolates after repeat intrarectal challenges. Although this prime-boost vaccine regimen failed to protect against SIVmac251 infection, 50% of vaccinated monkeys were protected from infection with SIVsmE660. Among SIVsmE660-infected animals, there was about a one-log reduction in peak plasma virus RNA in monkeys expressing the major histocompatibility complex class I allele Mamu-A*01, implicating cytotoxic T lymphocytes in the control of SIV replication once infection is established. Among Mamu-A*01-negative monkeys challenged with SIVsmE660, no CD8(+) T cell response or innate immune response was associated with protection against virus acquisition. However, low levels of neutralizing antibodies and an envelope-specific CD4(+) T cell response were associated with vaccine protection in these monkeys. Moreover, monkeys that expressed two TRIM5 alleles that restrict SIV replication were more likely to be protected from infection than monkeys that expressed at least one permissive TRIM5 allele. This study begins to elucidate the mechanisms of vaccine protection against immunodeficiency viruses and highlights the need to analyze these immune and genetic correlates of protection in future trials of HIV vaccine strategies.

The serine protease inhibitors (serpins) are anti-inflammatory proteins that have various functions. By screening a diverse panel of viruses, we demonstrate that the serpin antithrombin III (ATIII) has a broad-spectrum anti-viral activity for HIV-1, HCV and HSV. To investigate the mechanism of action in more detail we investigated the HIV-1 inhibition. Using gene-expression arrays we found that multiple host cell signal transduction pathways were activated by ATIII in HIV-1 infected cells but not in uninfected controls. Moreover, the signal pathways initiated by ATIII treatment, were more than 200-fold increased by the use of heparin-activated ATIII. The most up-regulated transcript in HIV-1 infected cells was prostaglandin synthetase-2 (PTGS2). Furthermore, we found that over-expression of PTGS2 reduced levels of HIV-1 replication in human PBMC. These findings suggest a central role for serpins in the host innate anti-viral response. Host factors such as PTGS2 elicited by ATIII treatment could be exploited in the development of novel anti-viral interventions.

We characterized the evolution of simian immunodeficiency virus (SIV) in the male genital tract by examining blood- and semen-associated virus from experimentally and sham vaccinated rhesus monkeys during primary infection. At the time of peak virus replication, SIV sequences were intermixed between the blood and semen supporting a scenario of high-level virus "spillover" into the male genital tract. However, at the time of virus set point, compartmentalization was apparent in 4 of 7 evaluated monkeys, likely as a consequence of restricted virus gene flow between anatomic compartments after the resolution of primary viremia. These findings suggest that SIV replication in the male genital tract evolves to compartmentalization after peak viremia resolves.

Background: We have evaluated an attenuated Listeria monocytogenes (Lm) candidate vaccine vector in nonhuman primates using a delivery regimen relying solely on oral vaccination. We sought to determine the impact of prior Lm vector exposure on the development of new immune responses against HIV antigens., Findings: Two groups of rhesus macaques one Lm naive, the other having documented prior Lm vector exposures, were evaluated in response to oral inoculations of the same vector expressing recombinant HIV-1 Gag protein. The efficacy of the Lm vector was determined by ELISA to assess the generation of anti-Listerial antibodies; cellular responses were measured by HIV-Gag specific ELISpot assay. Our results show that prior Lm exposures did not diminish the generation of de novo cellular responses against HIV, as compared to Listeria-naïve monkeys. Moreover, empty vector exposures did not elicit potent antibody responses, consistent with the intracellular nature of Lm., Conclusions: The present study demonstrates in a pre-clinical vaccine model, that prior oral immunization with an empty Lm vector does not diminish immunogenicity to Lm-expressed HIV genes. This work underscores the need for the continued development of attenuated Lm as an orally deliverable vaccine.

Post hoc analysis of the phase 2b Step study evaluating a recombinant adenovirus serotype 5 (rAd5)-based HIV-1 vaccine candidate suggested a potential increased risk of HIV-1 acquisition in subjects who were baseline Ad5 seropositive and uncircumcised. These concerns had a profound impact on the HIV-1 vaccine development field, although the mechanism underlying this observation remains unknown. It has been hypothesized that rAd5 vaccination of baseline Ad5-seropositive individuals may have resulted in anamnestic, vector-specific CD4(+) T lymphocytes that could have trafficked to mucosal sites and served as increased targets for HIV-1 infection. Here we show that Ad5-specific CD4(+) T lymphocyte responses at mucosal sites following rAd5-Gag/Pol/Nef vaccination were comparable in rhesus monkeys with and without baseline Ad5 immunity. Moreover, the total cellular inflammatory infiltrates and the CD3(+), CD4(+), HLA-DR(+), Ki67(+), and langerin(+) cellular subpopulations in colorectal and foreskin mucosa were similar in both groups. Thus, no greater trafficking of Ad5-specific CD4(+) T lymphocytes to mucosal target sites was observed following rAd5 vaccination of rhesus monkeys with baseline Ad5 immunity. These findings from this nonhuman primate model provide evidence against the hypothesis that recruitment of vector-specific target cells to mucosal sites led to increased HIV-1 acquisition in Ad5-seropositive, uncircumcised vaccinees in the Step study.

CCL3 is a ligand for the HIV-1 co-receptor CCR5. There have recently been conflicting reports in the literature concerning whether CCL3-like gene (CCL3L) copy number variation (CNV) is associated with resistance to HIV-1 acquisition and with both viral load and disease progression following infection with HIV-1. An association has also been reported between CCL3L CNV and clinical sequelae of the simian immunodeficiency virus (SIV) infection in vivo in rhesus monkeys. The present study was initiated to explore the possibility of an association of CCL3L CNV with the control of virus replication and AIDS progression in a carefully defined cohort of SIVmac251-infected, Indian-origin rhesus monkeys. Although we demonstrated extensive variation in copy number of CCL3L in this cohort of monkeys, CCL3L CNV was not significantly associated with either peak or set-point plasma SIV RNA levels in these monkeys when MHC class I allele Mamu-A*01 was included in the models or progression to AIDS in these monkeys. With 66 monkeys in the study, there was adequate power for these tests if the correlation of CCL3L and either peak or set-point plasma SIV RNA levels was 0.34 or 0.36, respectively. These findings call into question the premise that CCL3L CNV is important in HIV/SIV pathogenesis., Competing Interests: The authors have declared that no competing interests exist.

While the simian immunodeficiency virus (SIV)-infected rhesus monkey is an important animal model for human immunodeficiency virus type 1 (HIV-1) infection of humans, much remains to be learned about the evolution of the humoral immune response in this model. In HIV-1 infection, autologous neutralizing antibodies emerge 2 to 3 months after infection. However, the ontogeny of the SIV-specific neutralizing antibody response in mucosally infected animals has not been defined. We characterized the kinetics of the autologous neutralizing antibody response to the transmitted/founder SIVmac251 using a pseudovirion-based TZM-bl cell assay and monitored env sequence evolution using single-genome amplification in four rhesus animals that were infected via intrarectal inoculations. We show that the SIVmac251 founder viruses induced neutralizing antibodies at 5 to 8 months after infection. Despite their slow emergence and low titers, these neutralizing antibodies selected for escape mutants that harbored substitutions and deletions in variable region 1 (V1), V2, and V4 of Env. The neutralizing antibody response was initially focused on V4 at 5 to 8 months after infection and then targeted V1/V2 and V4 by 16 months. These findings reveal a striking delay in the development of neutralizing antibodies in SIVmac-infected animals, thus raising questions concerning the suitability of SIVmac251 as a challenge strain to screen AIDS vaccines that elicit neutralizing antibodies as a means to prevent virus acquisition. They also illustrate the capacity of the SIVmac quasispecies to modify antigenic determinants in response to very modest titers of neutralizing antibodies.