Disruption of MeCP2-TCF20 complex underlies distinct neurodevelopmental disorders.

MeCP2 is associated with Rett syndrome (RTT), MECP2 duplication syndrome, and a number of conditions with isolated features of these diseases, including autism, intellectual disability, and motor dysfunction. MeCP2 is known to broadly bind methylated DNA, but the precise molecular mechanism driving disease pathogenesis remains to be determined. Using proximity-dependent biotinylation (BioID), we identified a transcription factor 20 (TCF20) complex that interacts with MeCP2 at the chromatin interface. Importantly, RTT-causing mutations in MECP2 disrupt this interaction. TCF20 and MeCP2 are highly coexpressed in neurons and coregulate the expression of key neuronal genes. Reducing Tcf20 partially rescued the behavioral deficits caused by MECP2 overexpression, demonstrating a functional relationship between MeCP2 and TCF20 in MECP2 duplication syndrome pathogenesis. We identified a patient exhibiting RTT-like neurological features with a missense mutation in the PHF14 subunit of the TCF20 complex that abolishes the MeCP2-PHF14-TCF20 interaction. Our data demonstrate the critical role of the MeCP2-TCF20 complex for brain function.

Binding of adenovirus species C hexon to prothrombin and the influence of hexon on vector properties in vitro and in vivo.

The majority of adenovirus (Ad) vectors are based on human Ad type 5, which is a member of Ad species C. Species C also includes the closely-related types 1, 2, 6, 57 and 89. It is known that coagulation factors bind to Ad5 hexon and play a key role in the liver tropism of Ad5 vectors, but it is unclear how coagulation factors affect vectors derived from other species C Ads. We evaluated species C Ad vectors both in vitro and following intravenous injection in mice. To assess the impact of hexon differences, we constructed chimeric Ad5 vectors that contain the hexon hypervariable regions from other species C types, including vectors with hexon mutations that decreased coagulation factor binding. After intravenous injection into mice, vectors with Ad5 or Ad6 hexon had strong liver tropism, while vectors with chimeric hexon from other Ad types had weaker liver tropism due to inhibition by natural antibodies and complement. In addition, we discovered a novel ability of hexon to bind prothrombin, which is the most abundant coagulation factor in blood, and we found striking differences in the affinity of Ads for human, mouse and bovine coagulation factors. When compared to Ad5, vectors with non-Ad5 species C hexons had considerably higher affinity for both human and mouse prothrombin. Most of the vectors tested were strongly dependent on coagulation factors for liver transduction, but vectors with chimeric Ad6 hexon showed much less dependence on coagulation factors than other vectors. We found that in vitro neutralization experiments with mouse serum predicted in vivo behavior of Ad5 vectors, but in vitro experiments did not predict the in vivo behavior of vectors based on other Ad types. In sum, hexons from different human Ad species C viruses confer diverse properties on vectors, including differing abilities to target the liver.

Dimensions of anxiety in Major depressive disorder and their use in predicting antidepressant treatment outcome: an iSPOT-D report.

BACKGROUND: Major depressive disorder (MDD) commonly co-occurs with clinically significant levels of anxiety. However, anxiety symptoms are varied and have been inconsistently associated with clinical, functional, and antidepressant treatment outcomes. We aimed to identify and characterise dimensions of anxiety in people with MDD and their use in predicting antidepressant treatment outcome. METHOD: 1008 adults with a current diagnosis of single-episode or recurrent, nonpsychotic, MDD were assessed at baseline on clinical features and cognitive/physiological functioning. Participants were then randomised to one of three commonly prescribed antidepressants and reassessed at 8 weeks regarding symptom change, as well as remission and response, on the 17-item Hamilton Rating Scale Depression (HRSD17) and the 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR16). Exploratory factor analysis was used on items from scales assessing anxiety symptoms, and resulting factors were assessed against clinical features and cognitive/physiological functioning. Factors were also assessed on their ability to predict treatment outcome. RESULTS: Three factors emerged relating to stress, cognitive anxiety, and somatic anxiety. All factors showed high internal consistency, minimal cross-loadings, and unique clinical and functional profiles. Furthermore, only higher somatic anxiety was associated with poorer QIDS-SR16 remission, even after adjusting for covariates and multiple comparisons. CONCLUSIONS: Anxiety symptoms in people with MDD can be separated onto distinct factors that differentially respond to treatment outcome. Furthermore, these factors do not align with subscales of established measures of anxiety. Future research should consider cognitive and somatic symptoms of anxiety separately when assessing anxiety in MDD and their use in predicting treatment outcome.

Annual variation in attentional response after methylphenidate treatment.

Prevalence rates of attention-deficit/hyperactivity disorder (ADHD) differ with geographical areas varying in sunlight intensity. Sun- or daylight reaching the retina establishes entrainment of the circadian clock to daylight. Changes herein, hence, alterations in clock alignment, could be reflected indirectly in inattention via sleep duration. We here studied (1) annual variation in inattention at treatment initiation; (2) annual variation in response to ADHD treatment [methylphenidate (MPH)] by day of treatment initiation; and (3) dose dependence. We predicted least baseline inattention during a period of high sunlight intensity implying more room for improvement (i.e., a better treatment response) when sunlight intensity is low. These hypotheses were not confirmed. High-dose treated patients, however, had significantly better attention after treatment than low-dosed treated patients, only when treated in the period from winter to summer solstice. Change in solar irradiance (SI) during low-dosed treatment period was negatively related to attentional improvement. The above described findings were primarily found in inattention ratings and replicated in omission errors on a continuous performance task. Daylight and inattention have been proposed to be related via mediation of the circadian system. One mechanism of MPH may be to enhance sensitivity to the diurnal entrainment to sunlight and the question can be raised whether appropriate lighting could potentiate the effects of stimulants.

Hepatic glutamine synthetase augmentation enhances ammonia detoxification.

The urea cycle and glutamine synthetase (GS) are the two main pathways for waste nitrogen removal and their deficiency results in hyperammonemia. Here, we investigated the efficacy of liver-specific GS overexpression for therapy of hyperammonemia. To achieve hepatic GS overexpression, we generated a helper-dependent adenoviral (HDAd) vector expressing the murine GS under the control of a liver-specific expression cassette (HDAd-GS). Compared to mice injected with a control vector expressing an unrelated reporter gene (HDAd-alpha-fetoprotein), wild-type mice with increased hepatic GS showed reduced blood ammonia levels and a concomitant increase of blood glutamine after intraperitoneal injections of ammonium chloride, whereas blood urea was unaffected. Moreover, injection of HDAd-GS reduced blood ammonia levels at baseline and protected against acute hyperammonemia following ammonia challenge in a mouse model with conditional hepatic deficiency of carbamoyl phosphate synthetase 1 (Cps1), the initial and rate-limiting step of ureagenesis. In summary, we found that upregulation of hepatic GS reduced hyperammonemia in wild-type and Cps1-deficient mice, thus confirming a key role of GS in ammonia detoxification. These results suggest that hepatic GS augmentation therapy has potential for treatment of both primary and secondary forms of hyperammonemia.

Characterising anxiety in major depressive disorder and its use in predicting antidepressant treatment outcome: An iSPOT-D report.

OBJECTIVE: Major depressive disorder commonly co-occurs with one or more anxiety disorders or with clinically significant levels of anxiety symptoms. Although evidence suggests that anxious forms of depression are prognostic of poorer antidepressant outcomes, there is no clear definition of anxious depression, and inferences about clinical outcomes are thus limited. Our objective was to compare and evaluate definitions of anxious depression and anxiety-related scales according to clinical and antidepressant outcome criteria. METHOD: A total of 1008 adults with a current diagnosis of single-episode or recurrent, nonpsychotic, major depressive disorder were assessed at baseline on clinical features. Participants were then randomised to one of three antidepressants and reassessed at 8 weeks regarding remission and response of the 17-item Hamilton Rating Scale Depression (HRSD17) and the 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR16). Anxious depression was defined as major depressive disorder with one or more anxiety disorders or major depressive disorder with a HRSD17 anxiety/somatisation factor score ⩾7. Anxiety-related scales included the HRSD17 anxiety/somatisation factor and the 42-item Depression Anxiety Stress Scales (DASS42) anxiety and stress subscales. RESULTS: Anxious depression definitions showed poor agreement (κ = 0.15) and the HRSD17 anxiety/somatisation factor was weakly correlated with both DASS42 anxiety (r = 0.24) and stress subscales (r = 0.20). Anxious depression definitions were also associated with few impairments on clinical features and did not predict poorer antidepressant treatment outcome. However, higher DASS42 anxiety predicted poorer HRSD17 and QIDS-SR16 remission, and item-level analysis found higher scores on items 9 (situational anxiety) and 23 (somatic anxiety) of the DASS42 predicted poorer treatment outcome, even after adjusting for covariates and multiple comparisons. CONCLUSION: Common definitions of anxious depression show poor agreement and do not predict poorer treatment outcome. Anxiety symptoms may be better characterised dimensionally using DASS42 when predicting treatment outcome.

Conditional disruption of hepatic carbamoyl phosphate synthetase 1 in mice results in hyperammonemia without orotic aciduria and can be corrected by liver-directed gene therapy.

Carbamoyl phosphate synthetase 1 (CPS1) is a urea cycle enzyme that forms carbamoyl phosphate from bicarbonate, ammonia and ATP. Bi-allelic mutations of the CPS1 gene result in a urea cycle disorder presenting with hyperammonemia, often with reduced citrulline, and without orotic aciduria. CPS1 deficiency is particularly challenging to treat and lack of early recognition typically results in early neonatal death. Therapeutic interventions have limited efficacy and most patients develop long-term neurologic sequelae. Using transgenic techniques, we generated a conditional Cps1 knockout mouse. By loxP/Cre recombinase technology, deletion of the Cps1 locus was achieved in adult transgenic animals using a Cre recombinase-expressing adeno-associated viral vector. Within four weeks from vector injection, all animals developed hyperammonemia without orotic aciduria and died. Minimal CPS1 protein was detectable in livers. To investigate the efficacy of gene therapy for CPS deficiency following knock-down of hepatic endogenous CPS1 expression, we injected these mice with a helper-dependent adenoviral vector (HDAd) expressing the large murine CPS1 cDNA under control of the phosphoenolpyruvate carboxykinase promoter. Liver-directed HDAd-mediated gene therapy resulted in survival, normalization of plasma ammonia and glutamine, and 13% of normal Cps1 expression. A gender difference in survival suggests that female mice may require higher hepatic CPS1 expression. We conclude that this conditional murine model recapitulates the clinical and biochemical phenotype detected in human patients with CPS1 deficiency and will be useful to investigate ammonia-mediated neurotoxicity and for the development of cell- and gene-based therapeutic approaches.

In vivo transduction of primitive mobilized hematopoietic stem cells after intravenous injection of integrating adenovirus vectors.

Current protocols for hematopoietic stem/progenitor cell (HSPC) gene therapy, involving the transplantation of ex vivo genetically modified HSPCs are complex and not without risk for the patient. We developed a new approach for in vivo HSPC transduction that does not require myeloablation and transplantation. It involves subcutaneous injections of granulocyte-colony-stimulating factor/AMD3100 to mobilize HSPCs from the bone marrow (BM) into the peripheral blood stream and the IV injection of an integrating, helper-dependent adenovirus (HD-Ad5/35++) vector system. These vectors target CD46, a receptor that is uniformly expressed on HSPCs. We demonstrated in human CD46 transgenic mice and immunodeficient mice with engrafted human CD34+ cells that HSPCs transduced in the periphery home back to the BM where they stably express the transgene. In hCD46 transgenic mice, we showed that our in vivo HSPC transduction approach allows for the stable transduction of primitive HSPCs. Twenty weeks after in vivo transduction, green fluorescent protein (GFP) marking in BM HSPCs (Lin-Sca1+Kit- cells) in most of the mice was in the range of 5% to 10%. The percentage of GFP-expressing primitive HSPCs capable of forming multilineage progenitor colonies (colony-forming units [CFUs]) increased from 4% of all CFUs at week 4 to 16% at week 12, indicating transduction and expansion of long-term surviving HSPCs. Our approach was well tolerated, did not result in significant transduction of nonhematopoietic tissues, and was not associated with genotoxicty. The ability to stably genetically modify HSPCs without the need of myeloablative conditioning is relevant for a broader clinical application of gene therapy.

Nitric-oxide supplementation for treatment of long-term complications in argininosuccinic aciduria.

Argininosuccinate lyase (ASL) is required for the synthesis and channeling of L-arginine to nitric oxide synthase (NOS) for nitric oxide (NO) production. Congenital ASL deficiency causes argininosuccinic aciduria (ASA), the second most common urea-cycle disorder, and leads to deficiency of both ureagenesis and NO production. Subjects with ASA have been reported to develop long-term complications such as hypertension and neurocognitive deficits despite early initiation of therapy and the absence of documented hyperammonemia. In order to distinguish the relative contributions of the hepatic urea-cycle defect from those of the NO deficiency to the phenotype, we performed liver-directed gene therapy in a mouse model of ASA. Whereas the gene therapy corrected the ureagenesis defect, the systemic hypertension in mice could be corrected by treatment with an exogenous NO source. In an ASA subject with severe hypertension refractory to antihypertensive medications, monotherapy with NO supplements resulted in the long-term control of hypertension and a decrease in cardiac hypertrophy. In addition, the NO therapy was associated with an improvement in some neuropsychological parameters pertaining to verbal memory and nonverbal problem solving. Our data show that ASA, in addition to being a classical urea-cycle disorder, is also a model of congenital human NO deficiency and that ASA subjects could potentially benefit from NO supplementation. Hence, NO supplementation should be investigated for the long-term treatment of this condition.

Reduction of autonomic regulation in children and adolescents with conversion disorders.

OBJECTIVE: Conversion symptoms--functional neurological disturbances of body function--occur in association with extreme arousal, often in the context of emotional distress. The mechanisms that determine how and why such symptoms occur remain unknown. In this study, we used cardiac measures to assess arousal and cardiac autonomic regulation in children and adolescents who presented with acute conversion symptoms. METHODS: Heart rate was recorded in 57 children and adolescents (41 girls; 8.5-18 years old) with acute conversion symptoms and 57 age- and sex-matched healthy controls, during a resting condition and then during tasks involving cognitive and emotional activation. Arousal and autonomic regulation were assessed by measures of heart rate and heart rate variability. Psychological measures included attachment and emotional distress. RESULTS: Children and adolescents with conversion symptoms displayed higher autonomic arousal than did the controls, both at baseline and during task conditions (higher heart rate: baseline mean [standard deviation] = 82 [9.49] versus 74 [10.79] beats/min, p < .001; lower root mean squared successive differences-heart rate variability: 45.35 [27.97] versus 58.62 [25.69] ms(2), p = .012; and lower high-frequency heart rate variability: 6.50 [1.19] versus 7.01 [0.95] ln[ms(2)] p = .017), and decreased autonomic regulation (attenuation of heart rate increases across tasks). The baseline pattern of increased autonomic arousal was especially pronounced in children with coercive-preoccupied patterns of attachment. Autonomic measures were not correlated with measures of emotional distress. CONCLUSIONS: High autonomic arousal may be a precondition for generating conversion symptoms. Functional dysregulations of the cardiac, respiratory, and circulatory systems may mediate fainting episodes and nonepileptic seizures, and aberrant patterns of functional connectivity between motor areas and central arousal systems may be responsible for generating motor conversion symptoms.

Differential type I interferon-dependent transgene silencing of helper-dependent adenoviral vs. adeno-associated viral vectors in vivo.

We previously dissected the components of the innate immune response to Helper-dependent adenoviral vectors (HDAds) using genetic models, and demonstrated that multiple pattern recognition receptor signaling pathways contribute to this host response to HDAds in vivo. Based on analysis of cytokine expression profiles, type I interferon (IFN) mRNA is induced in host mouse livers at 1 hour post-injection. This type I IFN signaling amplifies cytokine expression in liver independent of the nature of vector DNA sequences after 3 hours post-injection. This type I IFN signaling in response to HDAds administration contributes to transcriptional silencing of both HDAd prokaryotic and eukaryotic DNA in liver. This silencing occurs early and is mediated by epigenetic modification as shown by in vivo chromatin immunoprecipitation (ChIP) with anti-histone deacetylase (HDAC) and promyelocytic leukemia protein (PML). In contrast, self-complementary adeno-associated viral vectors (scAAVs) showed significantly lower induction of type I IFN mRNA in liver compared to HDAds at both early and late time points. These results show that the type I IFN signaling dependent transgene silencing differs between AAV and HDAd vectors after liver-directed gene transfer.

SR-A and SREC-I are Kupffer and endothelial cell receptors for helper-dependent adenoviral vectors.

Helper-dependent adenoviral (HDAd) vectors can mediate long-term, high-level transgene expression from transduced hepatocytes with no chronic toxicity. However, a toxic acute response with potentially lethal consequences has hindered their clinical applications. Liver sinusoidal endothelial cells (LSECs) and Kupffer cells are major barriers to efficient hepatocyte transduction. Understanding the mechanisms of adenoviral vector uptake by non-parenchymal cells may allow the development of strategies aimed at overcoming these important barriers and to achieve preferential hepatocyte gene transfer with reduced toxicity. Scavenger receptors on Kupffer cells bind adenoviral particles and remove them from the circulation, thus preventing hepatocyte transduction. In the present study, we show that HDAd particles interact in vitro and in vivo with scavenger receptor-A (SR-A) and with scavenger receptor expressed on endothelial cells-I (SREC-I) and we exploited this knowledge to increase the efficiency of hepatocyte transduction by HDAd vectors in vivo through blocking of SR-A and SREC-I with specific fragments antigen-binding (Fabs).

Specific biases for identifying facial expression of emotion in children and adolescents with conversion disorders.

OBJECTIVE: This study aimed to assess how children and adolescents with conversion disorders identify universal facial expressions of emotion and to determine whether identification of emotion in faces relates to subjective emotional distress. METHODS: Fifty-seven participants (41 girls and 16 boys) aged 8.5 to 18 years with conversion disorders and 57 age- and sex-matched healthy controls completed a computerized task in which their accuracy and reaction times for identifying facial expressions were recorded. To isolate the effect of individual emotional expressions, participants' reaction times for each emotion (fear, anger, sadness, disgust, and happiness) were subtracted from their reaction times for the neutral control face. Participants also completed self-report measures of subjective emotional distress. RESULTS: Children/Adolescents with conversion disorders showed faster reaction times for identifying expressions of sadness (t(112) = -2.2, p = .03; 444 [609] versus 713 [695], p = .03) and slower reactions times for happy expressions (t(99.3) = 2.28, p ≤ .024; -33 [35] versus 174 [51], p = .024), compared with controls (F(33.75, 419.81) = 3.76, p < .001). There were no significant correlations (at the corrected p value of .01) between reaction times and subjective reports of perceived distress (r values ranged from 092 to 0.221; p > .018). There were also no differences in identification accuracy for any emotion (p > .82). CONCLUSIONS: The observation of faster reaction times to sad faces in children and adolescents with conversion disorders suggests increased vigilance and motor readiness to emotional signals that are potential threats to self or to close others. These effects may occur before conscious processing.

Safety profile, efficacy, and biodistribution of a bicistronic high-capacity adenovirus vector encoding a combined immunostimulation and cytotoxic gene therapy as a prelude to a phase I clinical trial for glioblastoma.

Adenoviral vectors (Ads) are promising gene delivery vehicles due to their high transduction efficiency; however, their clinical usefulness has been hampered by their immunogenicity and the presence of anti-Ad immunity in humans. We reported the efficacy of a gene therapy approach for glioma consisting of intratumoral injection of Ads encoding conditionally cytotoxic herpes simplex type 1 thymidine kinase (Ad-TK) and the immunostimulatory cytokine fms-like tyrosine kinase ligand 3 (Ad-Flt3L). Herein, we report the biodistribution, efficacy, and neurological and systemic effects of a bicistronic high-capacity Ad, i.e., HC-Ad-TK/TetOn-Flt3L. HC-Ads elicit sustained transgene expression, even in the presence of anti-Ad immunity, and can encode large therapeutic cassettes, including regulatory elements to enable turning gene expression "on" or "off" according to clinical need. The inclusion of two therapeutic transgenes within a single vector enables a reduction of the total vector load without adversely impacting efficacy. Because clinically the vectors will be delivered into the surgical cavity, normal regions of the brain parenchyma are likely to be transduced. Thus, we assessed any potential toxicities elicited by escalating doses of HC-Ad-TK/TetOn-Flt3L (1×10(8), 1×10(9), or 1×10(10) viral particles [vp]) delivered into the rat brain parenchyma. We assessed neuropathology, biodistribution, transgene expression, systemic toxicity, and behavioral impact at acute and chronic time points. The results indicate that doses up to 1×10(9) vp of HC-Ad-TK/TetOn-Flt3L can be safely delivered into the normal rat brain and underpin further developments for its implementation in a phase I clinical trial for glioma.

Balloon catheter delivery of helper-dependent adenoviral vector results in sustained, therapeutic hFIX expression in rhesus macaques.

Hemophilia B is an excellent candidate for gene therapy because low levels of factor IX (FIX) (≥1%) result in clinically significant improvement of the bleeding diathesis. Helper-dependent adenoviral (HDAd) vectors can mediate long-term transgene expression without chronic toxicity. To determine the potential for HDAd-mediated liver-directed hemophilia B gene therapy, we administered an HDAd expressing hFIX into rhesus macaques through a novel and minimally invasive balloon occlusion catheter-based method that permits preferential, high-efficiency hepatocyte transduction with low, subtoxic vector doses. Animals given 1 × 10(12) and 1 × 10(11) virus particle (vp)/kg achieved therapeutic hFIX levels for the entire observation period (up to 1,029 days). At 3 × 10(10) and 1 × 10(10) vp/kg, only subtherapeutic hFIX levels were achieved which were not sustained long-term. Balloon occlusion administration of HDAd was well tolerated with negligible toxicity. Five of six animals developed inhibitors to hFIX. These results provide important information in assessing the clinical utility of HDAd for hemophilia B gene therapy.

Brainmarker-I Differentially Predicts Remission to Various Attention-Deficit/Hyperactivity Disorder Treatments: A Discovery, Transfer, and Blinded Validation Study.

BACKGROUND: Attention-deficit/hyperactivity disorder is characterized by neurobiological heterogeneity, possibly explaining why not all patients benefit from a given treatment. As a means to select the right treatment (stratification), biomarkers may aid in personalizing treatment prescription, thereby increasing remission rates. METHODS: The biomarker in this study was developed in a heterogeneous clinical sample (N = 4249) and first applied to two large transfer datasets, a priori stratifying young males (<18 years) with a higher individual alpha peak frequency (iAPF) to methylphenidate (N = 336) and those with a lower iAPF to multimodal neurofeedback complemented with sleep coaching (N = 136). Blinded, out-of-sample validations were conducted in two independent samples. In addition, the association between iAPF and response to guanfacine and atomoxetine was explored. RESULTS: Retrospective stratification in the transfer datasets resulted in a predicted gain in normalized remission of 17% to 30%. Blinded out-of-sample validations for methylphenidate (n = 41) and multimodal neurofeedback (n = 71) corroborated these findings, yielding a predicted gain in stratified normalized remission of 36% and 29%, respectively. CONCLUSIONS: This study introduces a clinically interpretable and actionable biomarker based on the iAPF assessed during resting-state electroencephalography. Our findings suggest that acknowledging neurobiological heterogeneity can inform stratification of patients to their individual best treatment and enhance remission rates.

Adenovirus-retrovirus hybrid vectors achieve highly enhanced tumor transduction and antitumor efficacy in vivo.

Murine leukemia virus (MLV)-based replication-competent retrovirus (RCR) vectors have been shown to mediate efficient, selective, and persistent tumor transduction, thereby achieving significant therapeutic benefit in a wide variety of cancer models. To further augment the efficiency of this strategy, we have developed a delivery method employing a gutted adenovirus encoding an RCR vector (AdRCR); thus, tumor cells transduced with the adenoviral vector transiently become RCR vector producer cells in situ. As expected, high-titer AdRCR achieved significantly higher initial transduction levels in human cancer cells both in vitro and in vivo, as compared to the original RCR vector itself. Notably, even at equivalent initial transduction levels, more secondary RCR progeny were produced from AdRCR-transduced cells as compared to RCR-transduced cells, resulting in further acceleration of subsequent RCR replication kinetics. In pre-established tumor models in vivo, prodrug activator gene therapy with high-titer AdRCR could achieve enhanced efficacy compared to RCR alone, in a dose-dependent manner. Thus, AdRCR hybrid vectors offer the advantages of high production titers characteristic of adenovirus and secondary production of RCR in situ, which not only accelerates subsequent vector spread and progressive tumor transduction, but can also significantly enhance the therapeutic efficacy of RCR-mediated prodrug activator gene therapy.

Generation of a Kupffer cell-evading adenovirus for systemic and liver-directed gene transfer.

As much as 90% of an intravenously (i.v.) injected dose of adenovirus serotype 5 (Ad5) is absorbed and destroyed by liver Kupffer cells. Viruses that escape these cells can then transduce hepatocytes after binding factor X (FX). Given that interactions with FX and Kupffer cells are thought to occur on the Ad5 hexon protein, we replaced its exposed hypervariable regions (HVR) with those from Ad6. When tested in vivo in BALB/c mice and in hamsters, the Ad5/6 chimera mediated >10 times higher transduction in the liver. This effect was not due to changes in FX binding. Rather, Ad5/6 appeared to escape Kupffer cell uptake as evidenced by producing no Kupffer cell death in vivo, not requiring predosing in vivo, and being phagocytosed less efficiently by macrophages in vitro compared to Ad5. When tested as a helper-dependent adenovirus (Ad) vector, Ad5/6 mediated higher luciferase and factor IX transgene expression than either helper-dependent adenoviral 5 (HD-Ad5) or HD-Ad6 vectors. These data suggest that the Ad5/6 hexon-chimera evades Kupffer cells and may have utility for systemic and liver-directed therapies.

Modifications of adenovirus hexon allow for either hepatocyte detargeting or targeting with potential evasion from Kupffer cells.

In vivo gene transfer with adenovirus vectors would significantly benefit from a tight control of the adenovirus-inherent liver tropism. For efficient hepatocyte transduction, adenovirus vectors need to evade from Kupffer cell scavenging while delivery to peripheral tissues or tumors could be improved if both scavenging by Kupffer cells and uptake by hepatocytes were blocked. Here, we provide evidence that a single point mutation in the hexon capsomere designed to enable defined chemical capsid modifications may permit both detargeting from and targeting to hepatocytes with evasion from Kupffer cell scavenging. Vector particles modified with small polyethylene glycol (PEG) moieties specifically on hexon exhibited decreased transduction of hepatocytes by shielding from blood coagulation factor binding. Vector particles modified with transferrin or, surprisingly, 5,000 Da PEG or dextran increased hepatocyte transduction up to 18-fold independent of the presence of Kupffer cells. We further show that our strategy can be used to target high-capacity adenovirus vectors to hepatocytes emphasizing the potential for therapeutic liver-directed gene transfer. Our approach may lead to a detailed understanding of the interactions between adenovirus vectors and Kupffer cells, one of the most important barriers for adenovirus-mediated gene delivery.

Intrinsic Functional Connectomes Characterize Neuroticism in Major Depressive Disorder and Predict Antidepressant Treatment Outcomes.

BACKGROUND: Antidepressant efficacy in people with major depressive disorder remains modest, yet identifying treatment-predictive neurobiological markers may improve outcomes. While disruptions in functional connectivity within and between large-scale brain networks predict poorer treatment outcome, it is unclear whether higher trait neuroticism, which has been associated with generally poorer outcomes, contributes to these disruptions and to antidepressant-specific treatment outcomes. Here, we used whole-brain functional connectivity analysis to identify a neural connectomic signature of neuroticism and tested whether this signature predicted antidepressant treatment outcome. METHODS: Participants were 226 adults with major depressive disorder and 68 healthy control subjects who underwent functional magnetic resonance imaging and were assessed on clinical features at baseline. Participants with major depressive disorder were then randomized to 1 of 3 commonly prescribed antidepressants and after 8 weeks completed a second functional magnetic resonance imaging and were reassessed for depressive symptom remission/response. Baseline intrinsic functional connectivity between each pair of 436 brain regions was analyzed using network-based statistics to identify connectomic features associated with neuroticism. Features were then assessed on their ability to predict treatment outcome and whether they changed after 8 weeks of treatment. RESULTS: Higher baseline neuroticism was associated with greater connectivity within and between the salience, executive control, and somatomotor brain networks. Greater connectivity across these networks predicted poorer treatment outcome that was not mediated by baseline neuroticism, and connectivity strength decreased after antidepressant treatment. CONCLUSIONS: Our findings demonstrate that neuroticism is associated with organization of intrinsic neural networks that predict treatment outcome, elucidating its biological underpinnings and opportunity for better treatment personalization.