Faculty Bibliography

Background: Mucosal immunity may be critical to protection from HIV acquisition. Serum antibodies (Abs) targeted specifically to the region of the V2 loop harboring HIV's a4b7 integrin receptor binding site were associated with protection from HIV acquisition in humans. Mucosal Abs of this type may have been further associated with protection in a matched non-human primate model. Cholera toxin B (CTB) is a powerful mucosal adjuvant. We engineered CTB to display the SIVmac251 region of the V2 loop harboring the a4b7 site for testing in Rhesus macaques.
Method(s): The SIVmac251 a4b7 site was fused to CTB and the integrity of the immunogen was confirmed by X-ray crystallography. Antigenicity of the construct was confirmed with the ITS-12 monoclonal antibody. Serum immunogenicity was tested in rabbits and mucosal immunogenicity in young male Rhesus macaques. The macaque study compares 5 intramuscular (IM) and rectal topical co-administrations of CTB-V2 over 24 weeks to a matched-timeline regimen of two sequential DNA SIV gp120 immunizations followed by three ALVAC-SIV immunizations, the last two of which are coadministered with the IM and mucosal CTB-V2 protein boost.
Result(s): The engineered CTB-V2 protein binds galactose, which approximates mucosal GM1-gangliosides, binds ITS-12 potently and elicits titers >10k against the SIVmac251 a4b7 site in 5 of 5 rabbits. Rhesus macaques were successfully inoculated rectally with 200ug of this protein and tolerated the immunization well. The serum and mucosal responses were profiled.
Conclusion(s): Anti-V2, a4b7-site-targeted antibodies may be elicited by mucosal application of an engineered, validated CTB-V2 immunogen. Comparison to potent ALVAC-based regimens may provide insight into protective immune responses elicited by vaccination

Background: Cystic fibrosis (CF) may predispose patients to urinary stone disease (USD) via several proposed mechanisms including antibiotic exposure and intestinal malabsorption. Prevalence of USD in patients with CF was estimated at 2-6% in studies with mean age 16-27 years. These data are limited by small sample sizes and single-center settings. The CF Foundation Patient Registry (CFFPR) began collecting prevalence data on USD in 2006.
Method(s): We studied 29,396 patients in the CFFPR living in 2016 to calculate age-stratified prevalence of USD.USD was assessed by trained CF clinic staff at each encounter. For 15,531 patients age 18 or older we examined associations between age, BMI, demographics, CFTR mutation class, other clinical parameters, and prevalent USD using multivariate logistic regression.
Result(s): Overall prevalence of USD was 3.1% (95% CI 2.9-3.3%). Prevalence under age 18 years was 0.4% (0.3-0.5%), 18 to 24 years, 3.1% (2.7-3.6%), 25 to 34 years, 6.4% (5.8-7.1%), 35 to 44 years, 7.5% (6.5-8.5%), and 45 years and older, 6.7% (5.8-7.8%). Mean age of all patients was 21.3 years. We also calculated prevalence for age ranges 20-29, and 30-39 years to compare with published NHANES data for the general population. Stone prevalence was 4.8% and 7.1% in in CF patients within these two age cohorts, respectively, compared to 3.4 and 6.4% in NHANES. Multivariate adjusted odds ratios for stone prevalence were significant for female sex, OR 1.4 (95% CI 1.2-1.7), severe CFTR mutations, OR 1.8 (1.2-2.5), diabetes, OR 1.2 (1.0-1.5), hypertension, OR 1.4 (1.0-1.9), and chronic macrolide therapy, OR 1.3 (1.1-1.6). BMI was not associated with USD.
Conclusion(s): USD prevalence in CFFPR may be higher than in the general population and increased with age. Some risk factors for stone disease in the general population appear significant for adult patients with CF, including hypertension and diabetes. However, BMI did not show the same relationship. Several novel associations with USD in CF patients also were identified, including a greater prevalence in women. This study is limited by the method of USD assessment; it is possible patients with more severe CF had higher rates of reported asymptomatic stones incidentally diagnosed due to more frequent imaging. As life expectancy of people with CF increases, the prevalence of USD may also increase

Vanishing white matter (VWM) disease is an autosomal genetic leukodystrophy caused by mutations in subunits of eukaryotic translation initiation factor 2B (eIF2B). The clinical symptoms exhibit progressive loss of white matter in both hemispheres of the brain, accompanied by motor functions deterioration, neurological deficits, and early death. To date there is no treatment for VWM disease. The aim of this work was to expedite rational development of a therapeutic opportunity. Our approach was to design a computer-aided strategy for an efficient and reliable screening of drug-like molecules; and to use primary cultures of fibroblasts isolated from the Eif2b5^R132H/R132H VWM mouse model for screening. The abnormal mitochondria content phenotype of the mutant cells was chosen as a read-out for a simple cell-based fluorescent assay to assess the effect of the tested compounds. We obtained a hit rate of 0.04% (20 hits out of 50,000 compounds from the selected library). All primary hits decreased mitochondria content and brought it closer to WT levels. Structural similarities between our primary hits and other compounds with known targets allowed the identification of three putative cellular pathways/targets: 11β-hydroxysteroid dehydrogenase type 1, Sonic hedgehog (Shh), and Sigma-1-Receptor (S1R). In addition to initial experimental indication of Shh pathway impairment in VWM mouse brains, the current study provides evidence that S1R is a relevant target for pharmaceutical intervention for potential treatment of the disease. Specifically, we found lower expression level of S1R protein in fibroblasts, astrocytes, and whole brains isolated from Eif2b5^R132H/R132H compared to WT mice, and confirmed that one of the hits is a direct binder of S1R, acting as agonist. Furthermore, we provide evidence that treatment of mutant mouse fibroblasts and astrocytes with various S1R agonists corrects the functional impairments of their mitochondria and prevents their need to increase their mitochondria content for compensation purposes. Moreover, S1R activation enhances the survival rate of mutant cells under ER stress conditions, bringing it to WT levels. This study marks S1R as a target for drug development toward treatment of VWM disease. Moreover, it further establishes the important connection between white matter well-being and S1R-mediated proper mitochondria/ER function.

Background/UNASSIGNED:The corpus callosum is implicated in the pathophysiology of autism spectrum disorder (ASD). However, specific structural deficits and underlying mechanisms are yet to be well defined. Methods/UNASSIGNED:) diffusivities, which reflect myelination and microstructural organization of the extracellular space. The relationships between DKI metrics and processing speed, a cognitive feature known to be impaired in ASD, were also examined. Results/UNASSIGNED: > .05). Conclusion/UNASSIGNED:Decreased DKI metrics suggested that ASD may be associated with axonal deficits such as reduced axonal caliber and density in the corpus callosum, especially in the mid and posterior callosal areas. These data suggest that impaired interhemispheric connectivity may contribute to decreased processing speed in ASD participants.

Cogmed Working Memory Training (CWMT), an online cognitive training program developed for children, is an increasingly popular non-pharmacological intervention for ADHD amongst all ages, despite limited supporting evidence. The initial objective of the present work was to examine the short- and long-term impacts of CWMT on brain function in adults with ADHD. However, during the conduct of our study, we experienced multiple levels of failures in recruitment and retention that signaled potential concerns about the suitability of CWMT for adults with ADHD. This perspective piece aims to describe the difficulties we encountered in the context of studies examining the efficacy of CWMT in comparable populations. We trace these difficulties to the limited tolerability of the current CWMT structure for adults with ADHD, and review similar limitations in the literature. We suggest that efficacy of CWMT in children may be due in large part to close monitoring and scaffolding provided by clinicians and caregivers. For CWMT to have viability for widespread use in adults, greater support and structure will be needed for users to improve the likelihood of adherence. We discuss implications and considerations for future efforts in both research and clinical practice.

Background/UNASSIGNED:Neurofibromatosis 1 (NF1) is a monogenic model for syndromic autism. Statins rescue the social and cognitive phenotype in animal knockout models, but translational trials with subjects > 8 years using cognition/behaviour outcomes have shown mixed results. This trial breaks new ground by studying statin effects for the first time in younger children with NF1 and co-morbid autism and by using multiparametric imaging outcomes. Methods/UNASSIGNED:A single-site triple-blind RCT of simvastatin vs. placebo was done. Assessment (baseline and 12-week endpoint) included peripheral MAPK assay, awake magnetic resonance imaging spectroscopy (MRS; GABA and glutamate+glutamine (Glx)), arterial spin labelling (ASL), apparent diffusion coefficient (ADC), resting state functional MRI, and autism behavioural outcomes (Aberrant Behaviour Checklist and Clinical Global Impression). Results/UNASSIGNED: = 0.25) at baseline. Three of 12 (25%) simvastatin cases compared to none in placebo met 'clinical responder' criteria for behavioural outcome. Conclusions/UNASSIGNED:We show feasibility of peripheral MAPK assay and autism symptom measurement, but the study was not powered to test effectiveness. Multiparametric imaging suggests possible simvastatin effects in brain areas previously associated with NF1 pathophysiology and the social brain network. Trial registration/UNASSIGNED:EU Clinical Trial Register (EudraCT) 2012-005742-38 (www.clinicaltrialsregister.eu).

A fundamental problem in the field of obstructive sleep apnea (OSA) and memory is that it has historically minimized the basic neurobiology of sleep's role in memory. Memory formation has been classically divided into phases of encoding, processing/consolidation, and retrieval. An abundance of evidence suggests that sleep plays a critical role specifically in the processing/consolidation phase, but may do so differentially for memories that were encoded using particular brain circuits. In this review, we discuss some of the more established evidence for sleep's function in the processing of declarative, spatial navigational, emotional, and motor/procedural memories and more emerging evidence highlighting sleep's importance in higher order functions such as probabilistic learning, transitive inference, and category/gist learning. Furthermore, we discuss sleep's capacity for memory augmentation through targeted/cued memory reactivation. OSA - by virtue of its associated sleep fragmentation, intermittent hypoxia, and potential brain structural effects - is well positioned to specifically impact the processing/consolidation phase, but testing this possibility requires experimental paradigms in which memory encoding and retrieval are separated by a period of sleep with and without the presence of OSA. We argue that such paradigms should focus on the specific types of memory tasks for which sleep has been shown to have a significant effect. We discuss the small number of studies in which this has been done, in which OSA nearly uniformly negatively impacts offline memory processing. When periods of offline processing are minimal or absent and do not contain sleep, as is the case in the broad literature on OSA and memory, the effects of OSA on memory are far less consistent.

Objective-To study transfection efficiency of folate-modified chitosan (FA-CS) nanoparticles as a non-viral vector delivering pEGFP-C3plasmid (FA-CS/P) to 293T cells with or without the combination of ultrasound and microbubble. Method-pEGFP-C3 was used as reporter gene and FA-CS nanoparticles, which prepared by complex coagulation method were used as biological carriers. Transfection efficiency to 293T cells mediated by FA-CS/P nanoparticles, ultrasound (US) and microbubble (MB) was assessed by fluorescence microscopy and flow cytometry. Result-FA-CS/P nanoparticles have a particle size of 355.1 nm and zeta potential of 10.4 mV. Significant green fluorescence could be observed in CS/P group, FA-CS/P group, US+MB/P group, US+FA-CS/P group, Liposome 2000 (L) group under inverted fluorescence microscope, while US+MB+FA-CS/P group only scattered fluorescence observed. Result of flow cytometry showed that transfection rate of US+MB+FA-CS/P group was (2.0 ± 0.2)%, which was significantly lower than other groups (P＜0.05). CCK-8 experiments showed that cell vitality of US+MB+FA-CS/P was (64.1±4.6)%, which was also lower than other groups (P＜0.05). Conclusion-In this study, FA-CS was successfully synthesized. FA-CS could combine with pEGFP-C3 effectively forming nanoparticles with nanoparticle size, well dispersion, high encapsulation efficiency and no significant toxicity to cells. The application of ultrasound increased the transfection rate of FA-CS/P. However, while exposed to ultrasound and microbubble, the transfection rate of FA-CS/P decreased obviously, may indicating that there was no synergistic effect for gene transfection by the combination of ultrasound, folate modified chitosan and microbubbles.

A developing brain shows intense reorganization and heightened neuronal plasticity allowing for environmental modulation of its development. During early life, maternal care is a key factor of this environment and defects in this care can derail adaptive brain development and may result in susceptibility to neuropsychiatric disorders. Nevertheless, the mechanisms by which those maternal interactions immediately impact the offspring's brain activity to initiate the pathway to pathology are not well understood. We do know that multiple neurotransmitter systems are involved, including the serotonergic system, a key neuromodulator involved in brain development and emotional regulation. We tested the importance of the serotonergic system and pups' immediate neural response to maternal presence using wireless electrophysiological recordings, a novel approach allowing us to record neural activity during pups' interactions with their mother. We found that maternal contact modulates the P10-P12 rat pups' anterior cingulate cortex (ACC) activity by notably increasing local-field potential (LFP) power in low-frequency bands. We demonstrated, by blocking serotonergic receptors, that this increase is mediated through 5-HT2 receptors (5-HT2Rs). Finally, we showed in isolated pups that enhancing serotonergic transmission, using a selective-serotonin-reuptake-inhibitor, is sufficient to enhance LFP power in low-frequency bands in a pattern similar to that observed when the mother is in the nest. Our results highlight a significant contribution of the serotonergic system in mediating changes of cortical activity in pups related to maternal presence.