Creeping yeast: a simple, cheap and robust protocol for the identification of mating type in Saccharomyces cerevisiae.

Saccharomyces cerevisiae is an exceptional genetic system, with genetic crosses facilitated by its ability to be maintained in haploid and diploid forms. Such crosses are straightforward if the mating type/ploidy of the strains is known. Several techniques can determine mating type (or ploidy), but all have limitations. Here, we validate a simple, cheap and robust method to identify S. cerevisiae mating types. When cells of opposite mating type are mixed in liquid media, they 'creep' up the culture vessel sides, a phenotype that can be easily detected visually. In contrast, mixtures of the same mating type or with a diploid simply settle out. The phenotype is observable for several days under a range of routine growth conditions and with different media/strains. Microscopy suggests that cell aggregation during mating is responsible for the phenotype. Yeast knockout collection analysis identified 107 genes required for the creeping phenotype, with these being enriched for mating-specific genes. Surprisingly, the RIM101 signaling pathway was strongly represented. We propose that RIM101 signaling regulates aggregation as part of a wider, previously unrecognized role in mating. The simplicity and robustness of this method make it ideal for routine verification of S. cerevisiae mating type, with future studies required to verify its molecular basis.

Experimental infection of ostriches with H7N1 low pathogenic and H5N8 clade 2.3.4.4B highly pathogenic influenza A viruses.

Infection dynamics data for influenza A virus in a species is important for understanding host-pathogen interactions and developing effective control strategies. Seven-week-old ostriches challenged with H7N1 low pathogenic viruses (LPAIV) or clade 2.3.4.4B H5N8 high pathogenic viruses (HPAIV) were co- housed with non-challenged contacts. Clinical signs, virus shed in the trachea, cloaca, and feather pulp, and antibody responses were quantified over 14 days. H7N1 LPAIV-infected ostriches remained generally healthy with some showing signs of mild conjunctivitis and rhinitis attributed to Mycoplasma co-infection. Mean tracheal virus shedding titres in contact birds peaked 3 days (106.2 EID50 equivalents / ml) and 9 days (105.28 EID50 equivalents / ml) after introduction, lasting for at least 13 days post infection. Cloacal shedding was substantially lower and ceased within 10 days of onset, and low virus levels were detected in wing feather pulp up until day 14. H5N8 HPAIV -infected ostriches showed various degrees of morbidity, with 2/3 mortalities in the in-contact group. Mean tracheal shedding in contact birds peaked 8 days after introduction (106.32 EID50 equivalents/ ml) and lasted beyond 14 days in survivors. Cloacal shedding and virus in feather pulp was generally higher and more consistently positive compared to H7N1 LPAIV, and was also detectable at least until 14 days post infection in survivors. Antibodies against H5N8 HPAIV and H7N1 LPAIV only appeared after day 7 post exposure, with higher titres induced by the HPAIV compared to the LPAIV, and neuraminidase treatment was essential to remove non-specific inhibitors from the H5N8-positive antisera.

Targeted literature review of current treatments and unmet need in moderate rheumatoid arthritis in the United Kingdom.

OBJECTIVES: The burden and treatment landscape of RA is poorly understood. This research aimed to identify evidence on quality of life, caregiver burden, economic burden, treatment patterns and clinical outcomes for patients with moderate RA in the United Kingdom. METHODS: A systematic literature review was performed across multiple databases and screened against pre-defined inclusion criteria. RESULTS: A total of 2610 records were screened; seven studies presenting evidence for moderate RA were included. These patients were found to incur substantial burden, with moderate to severe levels of disability. Compared with patients in remission, moderate RA patients reported higher levels of disability and decreased EQ-5D utility scores. The majority of patients did not feel that their current therapy adequately controlled their disease or provided sufficient symptom relief. In the United Kingdom, the National Institute for Health and Care Excellence (NICE) have not approved advanced therapies (such as biological disease-modifying anti-rheumatic drugs) for patients with moderate disease, which restricts access for these patients. CONCLUSION: The evidence available on the burden of moderate RA is limited. Despite current treatments, moderate RA still has a substantial negative impact, given that a DAS28 disease activity score defined as being in the moderate range does not qualify them for access to advanced therapies in the United Kingdom. For these patients, there is a particular need for further studies that investigate their burden and the impact of treating them earlier. Such information would help guide future treatment decisions and ensure the most effective use of resources to gain the best outcomes for patients with moderate RA.

Proposal for a trial of early left ventricular venting during venoarterial extracorporeal membrane oxygenation for cardiogenic shock.

Objective: Patients with profound cardiogenic shock may require venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for circulatory support most commonly via the femoral vessels. The rate of cardiac recovery in this population remains low, possibly because peripheral VA-ECMO increases ventricular afterload. Whether direct ventricular unloading in peripheral VA-ECMO enhances cardiac recovery is unknown, but is being more frequently utilized. A randomized trial is warranted to evaluate the clinical effectiveness of percutaneous left ventricle venting to enhance cardiac recovery in the setting of VA-ECMO. Methods: We describe the rationale, design, and initial testing of a randomized controlled trial of VA-ECMO with and without percutaneous left ventricle venting using a percutaneous micro-axial ventricular assist device. Results: This is an ongoing prospective randomized controlled trial in adult patients with primary cardiac failure presenting in cardiogenic shock requiring peripheral VA-ECMO, designed to test the safety and effectiveness of percutaneous left ventricle venting in improving the rate of cardiac recovery. Conclusions: The results of this nonindustry-sponsored trial will provide critical information on whether left ventricle unloading in peripheral VA-ECMO is safe and effective.

Transcriptional response of vaginal epithelial cells to medroxyprogesterone acetate treatment results in decreased barrier integrity.

Medroxyprogesterone acetate (MPA) is a frequently used hormonal contraceptive that has been shown to significantly increase HIV-1 susceptibility by approximately 40 %. However, the underlying mechanism by which this occurs remains unknown. Here, we examined the biological response to MPA by vaginal epithelial cells, the first cells to encounter HIV-1 during sexual transmission, in order to understand the potential mechanism(s) of MPA-mediated increase of HIV-1 infection. Using microarray analysis and in vitro assays, we characterized the response of vaginal epithelial cells, grown in biologically relevant air-liquid interface (ALI) cultures, to physiological levels of female sex hormones, estradiol (E2), progesterone (P4), or MPA. Transcriptional profiling of E2, P4 or MPA-treated vaginal epithelial cells indicated unique transcriptional profiles associated with each hormone. MPA treatment increased transcripts of genes related to cholesterol/sterol synthesis and decreased transcripts related to cell division and cell-cell adhesion, results not seen with E2 or P4 treatments. MPA treatment also resulted in unique gene expression indicative of decreased barrier integrity. Functional assays confirmed that MPA, but not E2 or P4 treatments, resulted in increased epithelial barrier permeability and inhibited cell cycle progression. The effects of MPA on vaginal epithelial cells seen in this study may help explain the increase of HIV-1 infection in women who use MPA as a hormonal contraceptive.

Prehospital Perimortem Caesarean Section - A Survivor.

Cardiac arrest in pregnancy is rare. It has a reported incidence of approximately 1 in 30000 pregnancies worldwide and occurs prehospitally with rates of around 3 in every 100000 live births within the developed world. The management of maternal cardiac arrest is complicated by the anatomical and physiological changes of pregnancy, its rarity and clinician unfamiliarity. The presentation and the prehospital environment can make for an incredibly challenging, stressful and highly emotive scene. One aspect of maternal cardiac arrest management is the perimortem cesarean section, a surgical procedure that is potentially lifesaving for both mother and child. Although rarely reported in the field it is possible to successfully perform the procedure. This report details the emergent prehospital treatment of a 41-year-old woman pregnant with her first child of 30 weeks gestation. It describes a case of maternal cardiac arrest, her resuscitation and the undertaking of a prehospital perimortem cesarean section resulting in a neurologically intact infant survivor.

Myocardial Infarction Due to Coronary Artery Injury following High Force Blunt Trauma to the Upper Chest: A Case Illustrating the Prehospital, Hospital and Autopsy Findings.

Myocardial infarction (MI) is a rare complication of blunt chest trauma (BCT). We describe an extensive antero-lateral MI due to thrombosis of the left main stem coronary artery following a blow to the lower face and upper anterior chest during an industrial accident in a 52-year-old male. The patient presented with acute left ventricular failure. Our case highlights MI as an important differential in a BCT patient presenting with hypoxia where lung pathology has been excluded. We aim to highlight the importance of cardiac assessment in trauma scenarios particularly where patients are unable to report symptoms. Our patient sadly did not survive his injuries. This case describes MI following BCT from the initial prehospital presentation through to postmortem findings and adds to the limited literature on the pathological mechanisms underpinning this rare complication.

Interferon-ß induced in female genital epithelium by HIV-1 glycoprotein 120 via Toll-like-receptor 2 pathway acts to protect the mucosal barrier.

More than 40% of HIV infections occur via female reproductive tract (FRT) through heterosexual transmission. Epithelial cells that line the female genital mucosa are the first line of defense against HIV-1 and other sexually transmitted pathogens. These sentient cells recognize and respond to external stimuli by induction of a range of carefully balanced innate immune responses. Previously, we have shown that in response to HIV-1 gp120, the genital epithelial cells (GECs) from upper reproductive tract induce an inflammatory response that may facilitate HIV-1 translocation and infection. In this study, we report that the endometrial and endocervical GECs simultaneously induce biologically active interferon-ß (IFNß) antiviral responses following exposure to HIV-1 that act to protect the epithelial tight junction barrier. The innate antiviral response was directly induced by HIV-1 envelope glycoprotein gp120 and addition of gp120 neutralizing antibody inhibited IFNß production. Interferon-ß was induced by gp120 in upper GECs through Toll-like receptor 2 signaling and required presence of heparan sulfate on epithelial cell surface. The induction of IFNß was dependent upon activation of transcription factor IRF3 (interferon regulatory factor 3). The IFNß was biologically active, had a protective effect on epithelial tight junction barrier and was able to inhibit HIV-1 infection in TZM-bl indicator cells and HIV-1 replication in T cells. This is the first report that recognition of HIV-1 by upper GECs leads to induction of innate antiviral pathways. This could explain the overall low infectivity of HIV-1 in the FRT and could be exploited for HIV-1 prophylaxis.

Crystal Structures of Full-Length Lanosterol 14α-Demethylases of Prominent Fungal Pathogens Candida albicans and Candida glabrata Provide Tools for Antifungal Discovery.

Targeting lanosterol 14α-demethylase (LDM) with azole drugs provides prophylaxis and treatments for superficial and disseminated fungal infections, but cure rates are not optimal for immunocompromised patients and individuals with comorbidities. The efficacy of azole drugs has also been reduced due to the emergence of drug-resistant fungal pathogens. We have addressed the need to improve the potency, spectrum, and specificity for azoles by expressing in Saccharomyces cerevisiae functional, recombinant, hexahistidine-tagged, full-length Candida albicans LDM (CaLDM6×His) and Candida glabrata LDM (CgLDM6×His) and determining their X-ray crystal structures. The crystal structures of CaLDM6×His, CgLDM6×His, and ScLDM6×His have the same fold and bind itraconazole in nearly identical conformations. The catalytic domains of the full-length LDMs have the same fold as the CaLDM6×His catalytic domain in complex with posaconazole, with minor structural differences within the ligand binding pocket. Our structures give insight into the LDM reaction mechanism and phenotypes of single-site CaLDM mutations. This study provides a practical basis for the structure-directed discovery of novel antifungals that target LDMs of fungal pathogens.

Hormonal influence on HIV-1 transmission in the female genital tract: New insights from systems biology.

Although anti-retroviral treatments have significantly slowed down the spread of the HIV-1 pandemic, approximately 2 million new infections occur every year. The majority of new infections are in sub-Saharan Africa where rates of infection are much higher in women than men. Young women are disproportionately affected and have higher susceptibility to HIV-1. The complex interactions between HIV-1 and the female genital tract (FGT) and the mechanisms regulating susceptibility in women remain incompletely understood. In this review, we focus on the current understanding of the acute events that occur in the FGT following HIV-1 exposure with a particular focus on the effect of endogenous and exogenous sex hormones on HIV-1 susceptibility. We highlight the contribution of the recent transcriptomic and proteomic studies in providing new insights.

Evolution-Guided Structural and Functional Analyses of the HERC Family Reveal an Ancient Marine Origin and Determinants of Antiviral Activity.

In humans, homologous to the E6-AP carboxyl terminus (HECT) and regulator of chromosome condensation 1 (RCC1)-like domain-containing protein 5 (HERC5) is an interferon-induced protein that inhibits replication of evolutionarily diverse viruses, including human immunodeficiency virus type 1 (HIV-1). To better understand the origin, evolution, and function of HERC5, we performed phylogenetic, structural, and functional analyses of the entire human small-HERC family, which includes HERC3, HERC4, HERC5, and HERC6. We demonstrated that the HERC family emerged >595 million years ago and has undergone gene duplication and gene loss events throughout its evolution. The structural topology of the RCC1-like domain and HECT domains from all HERC paralogs is highly conserved among evolutionarily diverse vertebrates despite low sequence homology. Functional analyses showed that the human small HERCs exhibit different degrees of antiviral activity toward HIV-1 and that HERC5 provides the strongest inhibition. Notably, coelacanth HERC5 inhibited simian immunodeficiency virus (SIV), but not HIV-1, particle production, suggesting that the antiviral activity of HERC5 emerged over 413 million years ago and exhibits species- and virus-specific restriction. In addition, we showed that both HERC5 and HERC6 are evolving under strong positive selection, particularly blade 1 of the RCC1-like domain, which we showed is a key determinant of antiviral activity. These studies provide insight into the origin, evolution, and biological importance of the human restriction factor HERC5 and the other HERC family members.IMPORTANCE Intrinsic immunity plays an important role as the first line of defense against viruses. Studying the origins, evolution, and functions of proteins responsible for effecting this defense will provide key information about virus-host relationships that can be exploited for future drug development. We showed that HERC5 is one such antiviral protein that belongs to an evolutionarily conserved family of HERCs with an ancient marine origin. Not all vertebrates possess all HERC members, suggesting that different HERCs emerged at different times during evolution to provide the host with a survival advantage. Consistent with this, two of the more recently emerged HERC members, HERC5 and HERC6, displayed strong signatures of having been involved in an ancient evolutionary battle with viruses. Our findings provide new insights into the evolutionary origin and function of the HERC family in vertebrate evolution, identifying HERC5 and possibly HERC6 as important effectors of intrinsic immunity in vertebrates.

Transcriptional profiling of primary endometrial epithelial cells following acute HIV-1 exposure reveals gene signatures related to innate immunity.

PROBLEM: Genital epithelial cells (GECs) line the mucosal surface of the female genital tract (FGT) and are the first cells that interface with both commensal microbiota and sexually transmitted pathogens. Despite the protective barrier formed by GECs, the FGT is a major site of HIV-1 infection. This highlights the importance of studying the interaction of HIV-1 and GECs. METHOD OF STUDY: Using microarray analysis, we characterized the transcriptional profile of primary endometrial GECs grown in the presence or absence of physiological levels of E2 (10-9  mol/L) or P4 (10-7  mol/L) following acute exposure to HIV-1 for 6 hours. RESULTS: Acute exposure of primary endometrial GECs to HIV-1 resulted in the expression of genes related to inflammation, plasminogen activation, adhesion and diapedesis and interferon response. Interestingly, exposure to HIV-1 in the presence of E2 and P4 resulted in differential transcriptional profiles, suggesting that the response of primary endometrial GECs to HIV-1 exposure is modulated by female sex hormones. CONCLUSION: The gene expression signature of endometrial GECs indicates that the response of these cells may be key to determining host susceptibility to HIV-1 and that sex hormones modulate these interactions. This study allows us to explore possible mechanisms that explain the hormone-mediated fluctuation of HIV-1 susceptibility in women.

Medroxyprogesterone acetate-treated human, primary endometrial epithelial cells reveal unique gene expression signature linked to innate immunity and HIV-1 susceptibility.

PROBLEM: Medroxyprogesterone acetate (MPA), a progestin-based hormonal contraceptive designed to mimic progesterone, has been linked to increased human immunodeficiency virus (HIV-1) susceptibility. Genital epithelial cells (GECs) form the mucosal lining of the female genital tract (FGT) and provide the first line of protection against HIV-1. The impact of endogenous sex hormones or MPA on the gene expression profile of GECs has not been comprehensively documented. METHOD OF STUDY: Using microarray analysis, we characterized the transcriptional profile of primary endometrial epithelial cells grown in physiological levels of E2, P4, and MPA. RESULTS: Each hormone treatment altered the gene expression profile of GECs in a unique manner. Interestingly, although MPA is a progestogen, the gene expression profile induced by it was distinct from P4. MPA increased gene expression of genes related to inflammation and cholesterol synthesis linked to innate immunity and HIV-1 susceptibility. CONCLUSION: The analysis of gene expression profiles provides insights into the effects of sex hormones and MPA on GECs and allows us to posit possible mechanisms of the MPA-mediated increase in HIV-1 acquisition.

Remote classification from an airborne camera using image super-resolution.

The image processing technique known as super-resolution (SR), which attempts to increase the effective pixel sampling density of a digital imager, has gained rapid popularity over the last decade. The majority of literature focuses on its ability to provide results that are visually pleasing to a human observer. In this paper, we instead examine the ability of SR to improve the resolution-critical capability of an imaging system to perform a classification task from a remote location, specifically from an airborne camera. In order to focus the scope of the study, we address and quantify results for the narrow case of text classification. However, we expect the results generalize to a large set of related, remote classification tasks. We generate theoretical results through simulation, which are corroborated by experiments with a camera mounted on a DJI Phantom 3 quadcopter.

Structural and Functional Elucidation of Yeast Lanosterol 14α-Demethylase in Complex with Agrochemical Antifungals.

Azole antifungals, known as demethylase inhibitors (DMIs), target sterol 14α-demethylase (CYP51) in the ergosterol biosynthetic pathway of fungal pathogens of both plants and humans. DMIs remain the treatment of choice in crop protection against a wide range of fungal phytopathogens that have the potential to reduce crop yields and threaten food security. We used a yeast membrane protein expression system to overexpress recombinant hexahistidine-tagged S. cerevisiae lanosterol 14α-demethylase and the Y140F or Y140H mutants of this enzyme as surrogates in order characterize interactions with DMIs. The whole-cell antifungal activity (MIC50 values) of both the R- and S-enantiomers of tebuconazole, prothioconazole (PTZ), prothioconazole-desthio, and oxo-prothioconazole (oxo-PTZ) as well as for fluquinconazole, prochloraz and a racemic mixture of difenoconazole were determined. In vitro binding studies with the affinity purified enzyme were used to show tight type II binding to the yeast enzyme for all compounds tested except PTZ and oxo-PTZ. High resolution X-ray crystal structures of ScErg11p6×His in complex with seven DMIs, including four enantiomers, reveal triazole-mediated coordination of all compounds and the specific orientation of compounds within the relatively hydrophobic binding site. Comparison with CYP51 structures from fungal pathogens including Candida albicans, Candida glabrata and Aspergillus fumigatus provides strong evidence for a highly conserved CYP51 structure including the drug binding site. The structures obtained using S. cerevisiae lanosterol 14α-demethylase in complex with these agrochemicals provide the basis for understanding the impact of mutations on azole susceptibility and a platform for the structure-directed design of the next-generation of DMIs.

Comparative effectiveness of granulocyte colony-stimulating factors to prevent febrile neutropenia and related complications in cancer patients in clinical practice: A systematic review.

INTRODUCTION: Febrile neutropenia (FN) is a serious side-effect of myelosuppressive chemotherapy. Several clinical trials and observational studies have evaluated the effects of prophylactic granulocyte colony-stimulating factors (G-CSFs) on risk of FN and related complications; however, no systematic reviews have focused on effectiveness in routine clinical practice. Here, we perform a systematic review assessing the comparative effectiveness of prophylaxis with a long-acting G-CSF (pegfilgrastim) versus short-acting G-CSFs (filgrastim, lenograstim, and filgrastim biosimilars) in cancer patients in real-world clinical settings. METHODS: A systematic review was performed based on a pre-specified protocol and was consistent with the Cochrane Collaboration Handbook (2009) and the Centre for Reviews and Dissemination's Guidance for Undertaking Reviews in Health Care (2011). MEDLINE, Embase, BIOSIS, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library databases were searched for articles published from January 2002 to June 2014. Congress databases (MASCC/ASCO/ESMO) and Google Scholar were searched for abstracts published from January 2012 to August 2014. Filgrastim (NEUPOGEN®), lenograstim and nivestim (a filgrastim biosimilar) were the only short-acting G-CSFs and pegfilgrastim (Neulasta®) was the only long-acting G-CSF described in eligible studies. Outcomes of interest were FN, FN-related hospitalisation and other FN-related complications (death, chemotherapy dose delays and reductions, antimicrobial treatment, severe neutropenia and costs and resource use). RESULTS: Of 1259 unique records identified, 18 real-world observational studies met predefined inclusion criteria; 15 were retrospective studies, and 3 were prospective studies. Multiple tumour types, chemotherapy regimens and geographical regions were included. Seven studies provided statistical comparisons of the risk of FN; risk of FN among patients receiving prophylaxis with pegfilgrastim versus short-acting G-CSF was significantly lower in three studies, numerically lower in three studies, and numerically higher in one study. Six studies provided statistical comparisons of the risk of FN-related hospitalisation; risk of FN-related hospitalisation among patients receiving prophylaxis with pegfilgrastim versus short-acting G-CSF was significantly lower in all six studies, though some variation was seen in subanalyses. Data for other outcomes were sparse with available results being generally consistent with the results seen for risk of FN and FN-related hospitalisation. CONCLUSIONS: Based on the findings from this review of real-world comparative effectiveness studies, risks of FN and FN-related complications were generally lower for prophylaxis with pegfilgrastim versus prophylaxis with short-acting G-CSFs.

Spatial-frequency-based metric for image superresolution.

The image processing technique known as superresolution (SR) has the potential to allow engineers to specify lower resolution and, therefore, less expensive cameras for a given task by enhancing the base camera's resolution. This is especially true in the remote detection and classification of objects in the environment, such as aircraft or human faces. Performing each of these tasks requires a minimum image "sharpness" which is quantified by a maximum resolvable spatial frequency, which is, in turn, a function of the camera optics, pixel sampling density, and signal-to-noise ratio. Much of the existing SR literature focuses on SR performance metrics for candidate algorithms, such as perceived image quality or peak SNR. These metrics can be misleading because they also credit deblurring and/or denoising in addition to true SR. In this paper, we propose a new, task-based metric where the performance of an SR algorithm is, instead, directly tied to the probability of successfully detecting critical spatial frequencies within the scene.

Dysfunctional HIV-specific CD8+ T cell proliferation is associated with increased caspase-8 activity and mediated by necroptosis.

Decreased HIV-specific CD8(+) T cell proliferation is a hallmark of chronic infection, but the mechanisms of decline are unclear. We analyzed gene expression profiles from antigen-stimulated HIV-specific CD8(+) T cells from patients with controlled and uncontrolled infection and identified caspase-8 as a correlate of dysfunctional CD8(+) T cell proliferation. Caspase-8 activity was upregulated in HIV-specific CD8(+) T cells from progressors and correlated positively with disease progression and programmed cell death-1 (PD-1) expression, but negatively with proliferation. In addition, progressor cells displayed a decreased ability to upregulate membrane-associated caspase-8 activity and increased necrotic cell death following antigenic stimulation, implicating the programmed cell death pathway necroptosis. In vitro necroptosis blockade rescued HIV-specific CD8(+) T cell proliferation in progressors, as did silencing of necroptosis mediator RIPK3. Thus, chronic stimulation leading to upregulated caspase-8 activity contributes to dysfunctional HIV-specific CD8(+) T cell proliferation through activation of necroptosis and increased cell death.

Lentivector integration sites in ependymal cells from a model of metachromatic leukodystrophy: non-B DNA as a new factor influencing integration.

The blood-brain barrier controls the passage of molecules from the blood into the central nervous system (CNS) and is a major challenge for treatment of neurological diseases. Metachromatic leukodystrophy is a neurodegenerative lysosomal storage disease caused by loss of arylsulfatase A (ARSA) activity. Gene therapy via intraventricular injection of a lentiviral vector is a potential approach to rapidly and permanently deliver therapeutic levels of ARSA to the CNS. We present the distribution of integration sites of a lentiviral vector encoding human ARSA (LV-ARSA) in murine brain choroid plexus and ependymal cells, administered via a single intracranial injection into the CNS. LV-ARSA did not exhibit a strong preference for integration in or near actively transcribed genes, but exhibited a strong preference for integration in or near satellite DNA. We identified several genomic hotspots for LV-ARSA integration and identified a consensus target site sequence characterized by two G-quadruplex-forming motifs flanking the integration site. In addition, our analysis identified several other non-B DNA motifs as new factors that potentially influence lentivirus integration, including human immunodeficiency virus type-1 in human cells. Together, our data demonstrate a clinically favorable integration site profile in the murine brain and identify non-B DNA as a potential new host factor that influences lentiviral integration in murine and human cells.