The rockefeller university

The hierarchical view of the ventral object recognition pathway is primarily based on feedforward mechanisms, starting from a fixed basis set of object primitives and ending on a representation of whole objects in the inferotemporal cortex. Here, we provide a different view. Rather than being a fixed "labeled line" for a specific feature, neurons are continually changing their stimulus selectivities on a moment-to-moment basis, as dictated by top-down influences of object expectation and perceptual task. Here, we also derive the selectivity for stimulus features from an ethologically curated stimulus set, based on a delayed match-to-sample task, that finds components that are informative for object recognition in addition to full objects, though the top-down effects were seen for both informative and uninformative components. Cortical areas responding to these stimuli were identified with functional MRI in order to guide placement of chronically implanted electrode arrays.

Clostridioides difficile causes debilitating colitis via secreted toxins that disrupt the intestinal barrier, and toxemia is associated with severe disease. Thus, therapies that fortify the intestinal barrier will reduce the severity of infection. Innate lymphoid cells (ILCs) are critical in the defense against acute C. difficile infection and represent a promising therapeutic target to limit disease. Here, we report that oral administration of the Toll-like receptor (TLR) 7 agonist R848 limits intestinal damage and protects mice from lethal C. difficile infection without impacting pathogen burden or altering the intestinal microbiome. R848 induced interleukin (IL)- 22 secretion by ILCs, leading to STAT3 phosphorylation in the intestinal epithelium and increased stem cell proliferation. Genetic ablation of ILCs, IL-22, or epithelial-specific STAT3 abrogated R848-mediated protection. R848 reduced intestinal permeability following infection and limited systemic toxin dissemination. Combined, these data identify an immunostimulatory molecule that activates IL-22 production in ILCs to enhance host tissue defenses following C. difficile infection.

Invariant object recognition-the ability to recognize objects across size, rotation, or context-is fundamental for making sense of a dynamic visual world. Though traditionally studied in primates, emerging evidence suggests rodents recognize objects across a range of identity-preserving transformations. We demonstrate that rats robustly perform visual object recognition and explore a neural pathway that may underlie this capacity by developing a pipeline from high-throughput behavior training to cellular resolution imaging in awake, head-fixed animals. Leveraging our optical approach, we systematically profile neurons in primary and higher-order visual areas and their spatial organization. We find that rat visual cortex exhibits several features similar to those observed in the primate ventral stream but also marked deviations, suggesting species-specific differences in how brains solve visual object recognition. This work reinforces the sophisticated visual abilities of rats and offers the technical foundation to use them as a powerful model for mechanistic perception.

A search is presented for fractionally charged particles with charges below 1e, using their small energy loss in the tracking detector as a key variable to observe a signal. The analyzed dataset corresponds to an integrated luminosity of 138 fb(-1) of proton-proton collisions collected at root s = 13 TeV in 2016-2018 at the CERN LHC. This is the first search at the LHC for new particles with a charge between e/3 and 0.9e, including an extension of previous results at a charge of 2e/3. Masses up to 640 GeV and charges as low as e/3 are excluded at 95% confidence level. These are the most stringent limits to date for the considered Drell-Yan-like production mode.

Nanobodies are single domain antibody variants proving themselves to be compelling tools for research, disease diagnostics, and as therapeutics targeting a myriad of disease agents. However, despite this potential, their mechanisms of paratope presentation and structural stabilization have not been fully explored. Here, we show that unlike monoclonal antibodies, a nanobody repertoire maximizes sampling of an antigen surface by binding a single antigen in at least three different orientations, which are correlated with their paratope composition. Structure-guided reengineering of several nanobodies reveals that a single point mutation within the paratope or a highly conserved region of a nanobody's framework 3 (FR3) can markedly improve antigen affinity, nanobody stability, or both. Conversely, we show the negative impact on antigen affinity when "over-stabilizing"nanobodies. Collectively our results provide a universal strategy to tune a nanobody's affinity by modifying specific residues that can readily be applied to guide nanobody optimization and functionalization.

Proteostasis involves degradation and recycling of proteins from organelles, membranes, and multiprotein complexes. These processes can depend on protein extraction and unfolding by the essential mechanoenzyme valosin-containing protein (VCP) and on ubiquitin chain remodeling by ubiquitin-specific proteases known as deubiquitinases (DUBs). How the activities of VCP and DUBs are coordinated is poorly understood. Here, we focus on the DUB VCPIP1, a VCP interactor required for post-mitotic Golgi and ER organization. We determine similar to 3.3 & Aring; cryogenic electron microscopy structures of VCP-VCPIP1 complexes in the absence of added nucleotide or the presence of an ATP analog. We find that up to 3 VCPIP1 protomers interact with the VCP hexamer to position VCPIP1's catalytic domain at the exit of VCP's central pore, poised to cleave ubiquitin following substrate unfolding. We observe competition between VCPIP1 and other cofactors for VCP binding and show that VCP stimulates VCPIP1's DUB activity. Together, our data suggest how the two enzyme activities can be coordinated to regulate proteostasis.

EFFISAYIL 1 was a randomized, placebo-controlled study of spesolimab, an anti-IL-36 receptor antibody, in patients presenting with a generalized pustular psoriasis flare. Treatment with spesolimab led to more rapid pustular and skin clearance versus treatment with placebo in approximately half of the patients. In this study, we present histologic, transcriptomic, and proteomic analyses of lesional and nonlesional skin and whole- blood samples collected from EFFISAYIL 1. Treatment with spesolimab led to a transition toward a nonlesional profile, with a downregulation of gene expressions in the skin of IL-36 transcripts (IL36a, IL36b, IL36g) and those associated with neutrophil recruitment (CXCL1, CXCL6, CXCL8), proinflammatory cytokines (IL6, IL19, IL20), and skin inflammation (DEFB4A, S100A7, S100A8). Changes were manifest at week 1 and sustained to week 8. At the systemic level, reductions in serum biomarkers of inflammation (IL-17, IL-8, IL-6) were sustained until 12 weeks after spesolimab treatment. Considerable overlap was observed in the spesolimab-induced changes in gene and protein expressions from skin and blood samples, demonstrating the molecular basis of the effects of spesolimab on controlling local and systemic inflammation. Data are consistent with the mode of action of spesolimab, whereby inhibition of the IL-36 pathway leads to subsequent reductions in the key local and systemic pathologic events associated with generalized pustular psoriasis flares.

Nuclear pore proteins (nucleoporins [Nups]) physically interact with hundreds of chromosomal sites, impacting transcription. In yeast, transcription factors mediate interactions between Nups and enhancers and promoters. To define the molecular basis of this mechanism, we exploited a separation-of-function mutation in the Gcn4 transcription factor that blocks its interaction with the nuclear pore complex (NPC). This mutation reduces the interaction of Gcn4 with the highly conserved nuclear export factor Crm1/Xpo1. Crm1 and Nups co-occupy enhancers, and Crm1 inhibition blocks interaction of the nuclear pore protein Nup2 with the genome. In vivo, Crm1 interacts stably with the NPC and in vitro, Crm1 binds directly to both Gcn4 and Nup2. Importantly, the interaction between Crm1 and Gcn4 requires neither Ran-guanosine triphosphate (GTP) nor the nuclear export sequence binding site. Finally, Crm1 and Ran-GTP stimulate DNA binding by Gcn4, suggesting that allosteric coupling between Crm1-Ran-GTP binding and DNA binding facilitates the docking of transcription-factor-bound enhancers at the NPC.

The cholinergic interneurons (ChIs) of the nucleus accumbens (NAc) have a critical role in the activity of this region, specifically in the context of major depressive disorder. To understand the circuitry regulating this behavior, we sought to determine the areas that directly project to these interneurons by utilizing the monosynaptic cell-specific tracing technique. Mapping showed monosynaptic projections that are exclusive to NAc ChIs. To determine if some of these projections are altered in a depression mouse model, we used mice that do not express the calcium-binding protein p11 specifically in ChIs (ChAT-p11 cKO) and display a depressive-like phenotype. Our data demonstrated that while the overall projection areas remain similar between wild type and ChAT-p11 cKO mice, the number of projections from the ventral hippocampus (vHIP) is significantly reduced in the ChAT-p11 cKO mice. Furthermore, using optogenetics and electrophysiology we showed that glutamatergic projections from vHIP to NAc ChIs are severely altered in mutant mice. These results show that specific alterations in the circuitry of the accumbal ChIs could play an important role in the regulation of depressive-like behavior, reward-seeking behavior in addictions, or psychiatric symptoms in neurodegenerative diseases.