A novel, intergenic enhancer contributes to Il2 gene expression via chromosomal looping

IL-2 is a key immunoregulatory cytokine with pleotropic effects on many immune cell types. Its expression is highly regulated in T cells through multiple signaling pathways, chromatin remodeling, DNA methylation, and cooperative transcription factor binding. Recently, we identified an evolutionarily conserved intergenic enhancer 83 kb upstream of the Il2 gene that augments transcription from the Il2 promoter and upstream regulatory region (URR) by >50-fold in recombinant reporter assays. Upon TCR/CD28 co-stimulation of primary CD4+ T cells, a long-range chromosomal loop is established between the −83 kb CNS and the endogenous Il2 promoter, and both regions become epigenetically marked by histone acetylation and methylation. To determine the relative contribution of the URR vs. this new distal element to inducible transcription of the Il2 gene, we deleted the URR or the −83 kb CNS in mice using CRISPR/CAS genome editing. Deletion of the URR (~500 bp beyond the TATA element) completely abolished the Il2 transcription by CD4+ T cells, while a ~500 bp deletion of the −83 kb CNS resulted in a 2- to 4-fold decrease in IL-2 production. Young mice deficient for the −83 kb enhancer exhibited no major defects in lymphoid development, however, mutant CD4+ T cells showed reduced proliferative capacity in vitro. Furthermore, TGFB-induced iTreg differentiation from mutant conventional CD4+ precursors was strongly impaired, but could be fully restored by addition of exogenous IL-2. These results show that induction of Il2 depends upon cooperation between the promoter-URR and at least one intergenic enhancer, and suggest mechanisms by which graded expression of Il2 might be achieved through ‘modular’ recruitment of distinct enhancer elements.

African-American patients with cancer Talking About Clinical Trials (TACT) with oncologists during consultations: evaluating the efficacy of tailored health messages in a randomised controlled trial-the TACT study protocol

INTRODUCTION

Low rates of accrual of African-American (AA) patients with cancer to therapeutic clinical trials (CTs) represent a serious and modifiable racial disparity in healthcare that impedes the development of promising cancer therapies. Suboptimal physician-patient consultation communication is a barrier to the accrual of patients with cancer of any race, but communication difficulties are compounded with AA patients. Providing tailored health messages (THM) to AA patients and their physician about CTs has the potential to improve communication, lower barriers to accrual and ameliorate health disparities.

OBJECTIVE

(1) Demonstrate the efficacy of THM to increase patient activation as measured by direct observation. (2) Demonstrate the efficacy of THM to improve patient outcomes associated with barriers to AA participation. (3) Explore associations among preconsultation levels of: (A) trust in medical researchers, (B) knowledge and attitudes towards CTs, (C) patient-family member congruence in decision-making, and (D) involvement/information preferences, and group assignment.

METHODS AND ANALYSIS

First, using established methods, we will develop THM materials. Second, the efficacy of the intervention is determined in a 2 by 2 factorial randomised controlled trial to test the effectiveness of (1) providing 357 AA patients with cancer with THM with 2 different 'depths' of tailoring and (2) either providing feedback to oncologists about the patients' trial THM or not. The primary analysis compares patient engaged communication in 4 groups preconsultation and postconsultation.

ETHICS AND DISSEMINATION

This study was approved by the Virginia Commonwealth University Institutional Review Board. To facilitate use of the THM intervention in diverse settings, we will convene 'user groups' at 3 major US cancer centres. To facilitate dissemination, we will post all materials and the implementation guide in publicly available locations.

TRIAL REGISTRATION NUMBER

NCT02356549.

Exercise during Haemodialysis: West of Scotland Pilot Study

Background: Exercise during dialysis (EDD) in End-Stage Renal Disease (ESRD) has been documented as an effective intervention to improving a patient's aerobic capacity. Aims: This pilot study aimed to confirm physiological improvements, to establish its safety and practicality and to form guidelines for a long-term study, leading to the integration of EDD in ESRD therapy. Methods: A total of 17 patients on hospital haemodialysis were recruited: ten exercisers (age 42.4 ± 12.6) and six controls (age 41.0 ± 8.3). Both groups were initially tested for estimated VO2max, heart rate, blood pressure, leg extension peak torque, anxiety and depression levels, as well as biochemical and haematological values. The exercisers then underwent cycling ergometer exercise sessions during dialysis, twice weekly, for a total of 12 sessions. Both groups were re-tested after this period. Results: All test and exercise sessions were completed without complication. Compliance was high with only 1 exerciser failing to complete all 12 sessions. The exercisers showed a statistically significant increase (p < 0.05) in EDD workrates (44.3 to 52.1 watts) during the 12 sessions and a reduction in anxiety (p < 0.05). Statistical analysis showed no other significant changes in either group after the 6-week period. Conclusion: This pilot study has confirmed that aerobic EDD is feasible and well accepted by patients on hospital haemodialysis. EDD reduced anxiety scores and showed a trend for an improved level of aerobic fitness.

Plasmonic gratings with nano-protrusions made by glancing angle deposition for single-molecule super-resolution imaging

Super-resolution imaging has been advantageous in studying biological and chemical systems, but the required equipment and platforms are expensive and unable to observe single-molecules at the high (μM) fluorophore concentrations required to study protein interaction and enzymatic activity. Here, a plasmonic platform was designed that utilized an inexpensively fabricated plasmonic grating in combination with a scalable glancing angle deposition (GLAD) technique using physical vapor deposition. The GLAD creates an abundance of plasmonic nano-protrusion probes that combine the surface plasmon resonance (SPR) from the periodic gratings with the localized SPR of these nano-protrusions. The resulting platform enables simultaneous imaging of a large area without point-by-point scanning or bulk averaging for the detection of single Cyanine-5 molecules in dye concentrations ranging from 50 pM to 10 μM using epifluorescence microscopy. Combining the near-field plasmonic nano-protrusion probes and super-resolution technique using localization microscopy, we demonstrate the ability to resolve grain sizes down to 65 nm. This plasmonic GLAD grating is a cost-effective super-resolution imaging substrate with potential applications in high-speed biomedical imaging over a wide range of fluorescent concentrations.

Rapid eye movements to a virtual target are biased by illusory context in the Poggendorff figure

In order to determine the influence of perceptual input upon oculomotor responses, we examined rapid saccadic eye movements made by healthy human observers to a virtual target defined by the extrapolated intersection of a pointer with a distant landing line. While corresponding perceptual judgments showed no evidence of systematic bias, eye movements showed a strong bias, in the direction of assimilation of the saccade trajectory to the shortest path between the end of the pointer and the landing line. Adding an abutting vertical inducing line to make an angle of 45 deg with the pointer led to a larger bias in the same direction as the classical Poggendorff illusion. This additional Poggendorff effect was similar in direction and magnitude for the eye movements and the perceptual responses. Latency and dynamics of the eye movements were closely similar to those recorded for a control task in which observers made a saccade from the start fixation to an explicit target on the landing line. Further experiments with inducing lines presented briefly at various times during the saccade latency period showed that the magnitude of the saccade bias was affected by inducer presentation during the saccade planning process, but not during the saccade itself. We conclude that the neural mechanisms for extrapolation can feed into the control of eye movements without obvious penalties in timing and accuracy and that this information can instantaneously modify motor response throughout the planning phase, suggesting close association between perceptual and motor mechanisms in the process of visuo-spatial extrapolation.

Aerosol droplet optical trap loading using surface acoustic wave nebulization

We demonstrate the use of surface acoustic wave nebulization (SAWN) to load optical traps. We show that the droplets sizes produced can be tuned by altering the RF frequency applied to the devices, which leads to more control over the sizes of trapped particles. Typically the size distribution of the liquid aerosols delivered using SAWN is smaller than via a standard commercial nebulization device. The ability to trap a range of liquids or small solid particles, not readily accessible using other ultrasonic devices, is also demonstrated both in optical tweezers and dual beam fiber traps.

An anti-CD154 domain antibody prolongs graft survival and induces Foxp3(+) iTreg in the absence and presence of CTLA-4 Ig

The use of monoclonal antibodies targeting the CD154 molecule remains one of the most effective means of promoting graft tolerance in animal models, but thromboembolic complications during early clinical trials have precluded their use in humans. Furthermore, the role of Fc-mediated deletion of CD154-expressing cells in the observed efficacy of these reagents remains controversial. Therefore, determining the requirements for anti-CD154-induced tolerance will instruct the development of safer but equally efficacious treatments. To investigate the mechanisms of action of anti-CD154 therapy, two alternative means of targeting the CD40-CD154 pathway were used: a nonagonistic anti-CD40 antibody and an Fc-silent anti-CD154 domain antibody. We compared these therapies to an Fc-intact anti-CD154 antibody in both a fully allogeneic model and a surrogate minor antigen model in which the fate of alloreactive cells could be tracked. Results indicated that anti-CD40 mAbs as well as Fc-silent anti-CD154 domain antibodies were equivalent to Fc-intact anti-CD154 mAbs in their ability to inhibit alloreactive T cell expansion, attenuate cytokine production of antigen-specific T cells and promote the conversion of Foxp3(+) iTreg. Importantly, iTreg conversion observed with Fc-silent anti-CD154 domain antibodies was preserved in the presence of CTLA4-Ig, suggesting that this therapy is a promising candidate for translation to clinical use.

Usability of virtual-reality simulation training in obstetric ultrasonography: a prospective cohort study

OBJECTIVE

To assess the usability of virtual-reality (VR) simulation for obstetric ultrasound trainees.

METHODS

Twenty-six participants were recruited: 18 obstetric ultrasound trainees (with little formal ultrasonography training) and eight certified experts. All performed five sequential VR-simulated crown-rump length (CRL) scans in a single session and three repetitions of biparietal diameter (BPD), occipitofrontal diameter (OFD) and femur length (FL) measurements. Outcome measures included mean percentage deviation from target for all measurements. Time taken to perform each type of scan was recorded.

RESULTS

The mean percentage difference for the first scan was significantly greater for the trainee group than for the expert group for BPD (P = 0.035), OFD (P = 0.010) and FL (P = 0.008) and for time taken for the first CRL (P < 0.001) and fetal biometry (including BPD, OFD and FL measurements) scan (P < 0.001), demonstrating that trainees were initially significantly less accurate and less efficient. Over subsequent scans, the trainees became more accurate for all measurements with a significant improvement shown for OFD and FL (P < 0.05). The time taken for trainees to complete CRL and fetal biometry scans decreased significantly (all P < 0.05) with repetition, to near-expert efficiency.

CONCLUSIONS

All participants were able to use the simulator and produce clinically meaningful biometry results. With repetition, beginners quickly approached near-expert levels of accuracy and speed. These data demonstrate that obstetricians with minimal experience can improve their ultrasonographic skills with short-phase VR-simulation training. The speed of improvement suggests that VR simulation might be useful as a warm-up exercise before clinical training sessions in order to reduce their impact on clinical service.