VISTA is an acidic pH-selective ligand for PSGL-1.

Co-inhibitory immune receptors can contribute to T cell dysfunction in patients with cancer1,2. Blocking antibodies against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1) partially reverse this effect and are becoming standard of care in an increasing number of malignancies3. However, many of the other axes by which tumours become inhospitable to T cells are not fully understood. Here we report that V-domain immunoglobulin suppressor of T cell activation (VISTA) engages and suppresses T cells selectively at acidic pH such as that found in tumour microenvironments. Multiple histidine residues along the rim of the VISTA extracellular domain mediate binding to the adhesion and co-inhibitory receptor P-selectin glycoprotein ligand-1 (PSGL-1). Antibodies engineered to selectively bind and block this interaction in acidic environments were sufficient to reverse VISTA-mediated immune suppression in vivo. These findings identify a mechanism by which VISTA may engender resistance to anti-tumour immune responses, as well as an unexpectedly determinative role for pH in immune co-receptor engagement.

Author Correction: Discovery of stimulation-responsive immune enhancers with CRISPR activation.

In this Letter, analysis of steady-state regulatory T (Treg) cell percentages from Il2ra enhancer deletion (EDEL) and wild-type (WT) mice revealed no differences between them (Extended Data Fig. 9d). This analysis included two mice whose genotypes were incorrectly assigned. Even after correction of the genotypes, no significant differences in Treg cell percentages were seen when data across experimental cohorts were averaged (as was done in Extended Data Fig. 9d). However, if we normalize the corrected data to account for variation among experimental cohorts, a subtle decrease in EDEL Treg cell percentages is revealed and, using the corrected and normalized data, we have redrawn Extended Data Fig. 9d in Supplementary Fig. 1. The Supplementary Information to this Amendment contains the corrected and reanalysed Extended Data Fig. 9d. The sentence "This enhancer deletion (EDEL) strain also had no obvious T cell phenotypes at steady state (Extended Data Fig. 9)." should read: "This enhancer deletion (EDEL) strain had a small decrease in the percentage of Treg cells (Extended Data Fig. 9).". This error does not affect any of the main figures in the Letter or the data from mice with the human autoimmune-associated single nucleotide polymorphism (SNP) knocked in or with a 12-base-pair deletion at the site (12DEL). In addition, we stated in the Methods that we observed consistent immunophenotypes of EDEL mice across three founders, but in fact, we observed consistent phenotypes in mice from two founders. This does not change any of our conclusions and the original Letter has not been corrected.

Discovery of stimulation-responsive immune enhancers with CRISPR activation.

The majority of genetic variants associated with common human diseases map to enhancers, non-coding elements that shape cell-type-specific transcriptional programs and responses to extracellular cues. Systematic mapping of functional enhancers and their biological contexts is required to understand the mechanisms by which variation in non-coding genetic sequences contributes to disease. Functional enhancers can be mapped by genomic sequence disruption, but this approach is limited to the subset of enhancers that are necessary in the particular cellular context being studied. We hypothesized that recruitment of a strong transcriptional activator to an enhancer would be sufficient to drive target gene expression, even if that enhancer was not currently active in the assayed cells. Here we describe a discovery platform that can identify stimulus-responsive enhancers for a target gene independent of stimulus exposure. We used tiled CRISPR activation (CRISPRa) to synthetically recruit a transcriptional activator to sites across large genomic regions (more than 100 kilobases) surrounding two key autoimmunity risk loci, CD69 and IL2RA. We identified several CRISPRa-responsive elements with chromatin features of stimulus-responsive enhancers, including an IL2RA enhancer that harbours an autoimmunity risk variant. Using engineered mouse models, we found that sequence perturbation of the disease-associated Il2ra enhancer did not entirely block Il2ra expression, but rather delayed the timing of gene activation in response to specific extracellular signals. Enhancer deletion skewed polarization of naive T cells towards a pro-inflammatory T helper (TH17) cell state and away from a regulatory T cell state. This integrated approach identifies functional enhancers and reveals how non-coding variation associated with human immune dysfunction alters context-specific gene programs.

Modulation of ellipses drawing by sonification.

Most studies on the regulation of speed and trajectory during ellipse drawing have used visual feedback. We used online auditory feedback (sonification) to induce implicit movement changes independently from vision. The sound was produced by filtering a pink noise with a band-pass filter proportional to movement speed. The first experiment was performed in 2D. Healthy participants were asked to repetitively draw ellipses during 45 s trials whilst maintaining a constant sonification pattern (involving pitch variations during the cycle). Perturbations were produced by modifying the slope of the mapping without informing the participants. All participants adapted spontaneously their speed: they went faster if the slope decreased and slower if it increased. Higher velocities were achieved by increasing both the frequency of the movements and the perimeter of the ellipses, but slower velocities were achieved mainly by decreasing the perimeter of the ellipses. The shape and the orientation of the ellipses were not significantly altered. The analysis of the speed-curvature power law parameters showed consistent modulations of the speed gain factor, while the exponent remained stable. The second experiment was performed in 3D and showed similar results, except that the main orientation of the ellipse also varied with the changes in speed. In conclusion, this study demonstrated implicit modulation of movement speed by sonification and robust stability of the ellipse geometry. Participants appeared to limit the decrease in movement frequency during slowing down to maintain a rhythmic and not discrete motor regimen.

Generation of knock-in primary human T cells using Cas9 ribonucleoproteins.

T-cell genome engineering holds great promise for cell-based therapies for cancer, HIV, primary immune deficiencies, and autoimmune diseases, but genetic manipulation of human T cells has been challenging. Improved tools are needed to efficiently "knock out" genes and "knock in" targeted genome modifications to modulate T-cell function and correct disease-associated mutations. CRISPR/Cas9 technology is facilitating genome engineering in many cell types, but in human T cells its efficiency has been limited and it has not yet proven useful for targeted nucleotide replacements. Here we report efficient genome engineering in human CD4(+) T cells using Cas9:single-guide RNA ribonucleoproteins (Cas9 RNPs). Cas9 RNPs allowed ablation of CXCR4, a coreceptor for HIV entry. Cas9 RNP electroporation caused up to ∼40% of cells to lose high-level cell-surface expression of CXCR4, and edited cells could be enriched by sorting based on low CXCR4 expression. Importantly, Cas9 RNPs paired with homology-directed repair template oligonucleotides generated a high frequency of targeted genome modifications in primary T cells. Targeted nucleotide replacement was achieved in CXCR4 and PD-1 (PDCD1), a regulator of T-cell exhaustion that is a validated target for tumor immunotherapy. Deep sequencing of a target site confirmed that Cas9 RNPs generated knock-in genome modifications with up to ∼20% efficiency, which accounted for up to approximately one-third of total editing events. These results establish Cas9 RNP technology for diverse experimental and therapeutic genome engineering applications in primary human T cells.

Investigating three types of continuous auditory feedback in visuo-manual tracking.

The use of continuous auditory feedback for motor control and learning is still understudied and deserves more attention regarding fundamental mechanisms and applications. This paper presents the results of three experiments studying the contribution of task-, error-, and user-related sonification to visuo-manual tracking and assessing its benefits on sensorimotor learning. First results show that sonification can help decreasing the tracking error, as well as increasing the energy in participant's movement. In the second experiment, when alternating feedback presence, the user-related sonification did not show feedback dependency effects, contrary to the error and task-related feedback. In the third experiment, a reduced exposure of 50% diminished the positive effect of sonification on performance, whereas the increase of the average energy with sound was still significant. In a retention test performed on the next day without auditory feedback, movement energy was still superior for the groups previously trained with the feedback. Although performance was not affected by sound, a learning effect was measurable in both sessions and the user-related group improved its performance also in the retention test. These results confirm that a continuous auditory feedback can be beneficial for movement training and also show an interesting effect of sonification on movement energy. User-related sonification can prevent feedback dependency and increase retention. Consequently, sonification of the user's own motion appears as a promising solution to support movement learning with interactive feedback.

Continuous Auditory Feedback of Eye Movements: An Exploratory Study toward Improving Oculomotor Control.

As eye movements are mostly automatic and overtly generated to attain visual goals, individuals have a poor metacognitive knowledge of their own eye movements. We present an exploratory study on the effects of real-time continuous auditory feedback generated by eye movements. We considered both a tracking task and a production task where smooth pursuit eye movements (SPEM) can be endogenously generated. In particular, we used a visual paradigm which enables to generate and control SPEM in the absence of a moving visual target. We investigated whether real-time auditory feedback of eye movement dynamics might improve learning in both tasks, through a training protocol over 8 days. The results indicate that real-time sonification of eye movements can actually modify the oculomotor behavior, and reinforce intrinsic oculomotor perception. Nevertheless, large inter-individual differences were observed preventing us from reaching a strong conclusion on sensorimotor learning improvements.

Post traumatic deafness: a pictorial review of CT and MRI findings.

UNLABELLED: Hearing loss is a common functional disorder after trauma, and radiologists should be aware of the ossicular, labyrinthine or brain lesions that may be responsible. After a trauma, use of a systematic approach to explore the main functional components of auditory pathways is essential. Conductive hearing loss is caused by the disruption of the conductive chain, which may be due to ossicular luxation or fracture. This pictorial review firstly describes the normal 2-D and 3-D anatomy of the ossicular chain, including the incudo-malleolar and incudo-stapedial joints. The role of 3-D CT in the post-traumatic evaluation of injury to the temporal bone is then evaluated. In the case of sensorineural hearing loss, CT can detect pneumolabyrinth and signs of perilymphatic fistulae but fails to detect subtle lesions within the inner ear, such as labyrinthine haemorrhage or localized brain axonal damage along central auditory pathways. The role that MRI with 3-D-FLAIR acquisition plays in the detection of inner ear haemorrhage and post-traumatic lesions of the brain parenchyma that may lead to auditory agnosia is also discussed. KEY POINTS: • The most common middle ear injuries are incudo-malleolar and incudo-stapedial joint luxation. • In patients with SNHL, CT can detect pneumolabyrinth or perilymphatic fistula • 3-D-FLAIR MRI appears the best sequence to highlight labyrinthine haemorrhage • Axonal damage and brain hematoma may lead to deafness.

Sensori-Motor Learning with Movement Sonification: Perspectives from Recent Interdisciplinary Studies.

This article reports on an interdisciplinary research project on movement sonification for sensori-motor learning. First, we describe different research fields which have contributed to movement sonification, from music technology including gesture-controlled sound synthesis, sonic interaction design, to research on sensori-motor learning with auditory-feedback. In particular, we propose to distinguish between sound-oriented tasks and movement-oriented tasks in experiments involving interactive sound feedback. We describe several research questions and recently published results on movement control, learning and perception. In particular, we studied the effect of the auditory feedback on movements considering several cases: from experiments on pointing and visuo-motor tracking to more complex tasks where interactive sound feedback can guide movements, or cases of sensory substitution where the auditory feedback can inform on object shapes. We also developed specific methodologies and technologies for designing the sonic feedback and movement sonification. We conclude with a discussion on key future research challenges in sensori-motor learning with movement sonification. We also point out toward promising applications such as rehabilitation, sport training or product design.

Scalar localization by cone-beam computed tomography of cochlear implant carriers: a comparative study between straight and periomodiolar precurved electrode arrays.

OBJECTIVE: To compare the incidence of dislocation of precurved versus straight flexible cochlear implant electrode arrays using cone-beam computed tomography (CBCT) image analyses. STUDY DESIGN: Consecutive nonrandomized case-comparison study. SETTINGS: Tertiary referral center. PATIENTS: Analyses of patients' CBCT images after cochlear implant surgery. INTERVENTION(S): Precurved and straight flexible electrode arrays from two different manufacturers were implanted. A round window insertion was performed in most cases. Two cases necessitated a cochleostomy. The patients' CBCT images were reconstructed in the coronal oblique, sagittal oblique, and axial oblique section. MAIN OUTCOME MEASURES: The insertion depth angle and the incidence of dislocation from the scala tympani to the scala vestibuli were determined. RESULTS: The CBCT images and the incidence of dislocation were analyzed in 54 patients (61 electrode arrays). Thirty-one patients were implanted with a precurved perimodiolar electrode array and 30 patients with a straight flexible electrode array. A total of nine (15%) scalar dislocations were observed in both groups. Eight (26%) scalar dislocations were observed in the precurved array group and one (3%) in the straight array group. Dislocation occurred at an insertion depth angle between 170 and 190 degrees in the precurved array group and at approximately 370 degrees in the straight array group. CONCLUSION: With precurved arrays, dislocation usually occurs in the ascending part of the basal turn of the cochlea. With straight flexible electrode arrays, the incidence of dislocation was lower, and it seems that straight flexible arrays have a higher chance of a confined position within the scala tympani than perimodiolar precurved arrays.

From ear to hand: the role of the auditory-motor loop in pointing to an auditory source.

Studies of the nature of the neural mechanisms involved in goal-directed movements tend to concentrate on the role of vision. We present here an attempt to address the mechanisms whereby an auditory input is transformed into a motor command. The spatial and temporal organization of hand movements were studied in normal human subjects as they pointed toward unseen auditory targets located in a horizontal plane in front of them. Positions and movements of the hand were measured by a six infrared camera tracking system. In one condition, we assessed the role of auditory information about target position in correcting the trajectory of the hand. To accomplish this, the duration of the target presentation was varied. In another condition, subjects received continuous auditory feedback of their hand movement while pointing to the auditory targets. Online auditory control of the direction of pointing movements was assessed by evaluating how subjects reacted to shifts in heard hand position. Localization errors were exacerbated by short duration of target presentation but not modified by auditory feedback of hand position. Long duration of target presentation gave rise to a higher level of accuracy and was accompanied by early automatic head orienting movements consistently related to target direction. These results highlight the efficiency of auditory feedback processing in online motor control and suggest that the auditory system takes advantages of dynamic changes of the acoustic cues due to changes in head orientation in order to process online motor control. How to design an informative acoustic feedback needs to be carefully studied to demonstrate that auditory feedback of the hand could assist the monitoring of movements directed at objects in auditory space.