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Hua, Y.

Publications and source records attributed to Hua, Y..

At least 55 records · Page 3Linked to original sources

Direct measurements of collagen fiber recruitment in the posterior pole of the eye

Collagen is the main load-bearing component of the peripapillary sclera (PPS) and lamina cribrosa (LC) in the eye. Whilst it has been shown that uncrimping and recruitment of the PPS and LC collagen fibers underlies the macro-scale nonlinear stiffening of both tissues with increased intraocular pressure (IOP), the uncrimping and recruitment as a function of local stretch have not been directly measured. This knowledge is crucial for the development of constitutive models associating micro and macro scales. In this project we measured local stretch-induced collagen fiber bundle uncrimping and recruitment curves of the PPS and LC. Thin coronal samples of PPS and LC of sheep eyes were mounted and stretched biaxially quasi-statically using a custom system. At each step, we imaged the PPS and LC with instant polarized light microscopy and quantified pixel-level (1.5 m/pixel) collagen fiber orientations. We used digital image correlation to measure the local stretch and quantified collagen crimp by the circular standard deviation of fiber orientations, or waviness. Local stretch-recruitment curves of PPS and LC approximated sigmoid functions. PPS recruited more fibers than the LC at the low levels of stretch. At 10% stretch the curves crossed with 75% bundles recruited. The PPS had higher uncrimping rate and waviness remaining after recruitment than the LC: 0.9{degrees} vs. 0.6{degrees} and 3.1{degrees} vs. 2.7{degrees}. Altogether our findings support describing fiber recruitment of both PPS and LC with sigmoid curves, with the PPS recruiting faster and at lower stretch than the LC, consistent with a stiffer tissue. Statement of SignificancePeripapillary sclera (PPS) and lamina cribrosa (LC) collagen recruitment behaviors are central to the nonlinear mechanical behavior of the posterior pole of the eye. How PPS and LC collagen fibers recruit under stretch is crucial to develop constitutive models of the tissues but remains unclear. We used image-based stretch testing to characterize PPS and LC collagen fiber bundle recruitment under local stretch. We found that fiber-level stretch-recruitment curves of PPS and LC approximated sigmoid functions. PPS recruited more fibers at a low stretch, but at 10% bundle stretch the two curves crossed with 75% bundles recruited. We also found that PPS and LC fibers had different uncrimping rates and non-zero wavinesss when recruited.

bioengineering↗

ImSpiRE: Image feature-aided spatial resolution enhancement method

The resolution of most spatially resolved transcriptomic technologies usually cannot attain the single-cell level, limiting their applications in biological discoveries. Here, we introduce ImSpiRE, an image feature-aided spatial resolution enhancement method for in situ capturing spatial transcriptome. Taking the information stored in histological images, ImSpiRE solves an optimal transport problem to redistribute the expression profiles of spots to construct new transcriptional profiles with enhanced resolution, together with imputing the gene expression profiles in unmeasured regions. Applications to multiple datasets confirm that ImSpiRE can enhance spatial resolution to the subspot level while contributing to the discovery of tissue domains, signaling communication patterns, and spatiotemporal characterization.

bioinformatics↗

TUMOR ENDOTHELIAL CELL AUTOPHAGY IS A KEY VASCULAR-IMMUNE CHECKPOINT IN MELANOMA

Tumor endothelial cells (TECs) actively repress inflammatory responses and maintain an immune-excluded tumor phenotype. However, the molecular mechanisms that sustain TEC-mediated immunosuppression remain largely elusive. Here, we show that autophagy ablation in TECs boosts antitumor immunity by supporting infiltration and effector function of T cells, thereby restricting melanoma growth. In melanoma-bearing mice, loss of TEC autophagy leads to the transcriptional expression of an immunostimulatory/inflammatory TEC phenotype driven by heightened NF-kB and STING signaling. In line, single-cell transcriptomic datasets from melanoma patients disclose an enriched InflammatoryHigh/AutophagyLow TEC phenotype in correlation with clinical responses to immunotherapy. Congruently, patients responding to immunotherapy exhibit an increased presence of inflamed vessels, interfacing with infiltrating CD8+ T cells. Mechanistically, STING-dependent immunity in TECs is not critical for the immunomodulatory effects of autophagy ablation, since NF-kB-driven inflammation remains functional in STING/ATG5 double knockout TECs. Hence, autophagy is a principal tumor vascular anti-inflammatory mechanism dampening melanoma antitumor immunity.

cancer biology↗

HCC-1 accelerates atherosclerosis by inducing endothelial cells and macrophages pyroptosis and serves as an early diagnostic biomarker

BACKGROUNDHCC-1 (Hemofiltrate CC chemokine-1), a CC-type chemokine, exerts function to change intracellular calcium concentration, induce leukocyte and manipulate enzyme release especially in monocytes. It has been reported that HCC-1 could predict the persistent acute kidney injury (AKI) or suppress hepatocellular carcinoma (HCC) by modulating cell cycle and promoting apoptosis, but the effect of HCC-1 on atherosclerosis is poorly understood. Here, we aimed to clarify the function and mechanism of HCC-1 in atherosclerosis and whether it could serve as a novel biomarker for the diagnosis of atherosclerosis. METHODSHCC-1 expression in serum, atherosclerotic plaques and normal arterial tissue from patients with atherosclerosis and control group was assessed by enzyme-linked immunosorbent assay, immunohistochemistry and con-focal microscope. The atherosclerotic model of HCC-1 overexpressing mice and control mice were generated by infection of AAV9-HCC-1 on an ApoE-/- background. Cell adhesion, polarization and pyroptosis were evaluated in vitro. The relationship between HCC-1 concentration in serum and atherosclerosis was analyzed in patients with atherosclerosis. RESULTSHCC-1 expression increased in patients with atherosclerosis both in serum and atherosclerotic plaque. HCC-1 overexpression mice had an enhancement in macrophage accumulation in plaque, higher levels of inflammatory factors, increased pyroptotic rate in ECs and Macrophages in plaque and decreased atherosclerotic plaque stability. In vitro, HCC-1 promoted monocytes to adhere to endothelial cells and M1 polarization, induced inflammation and pyroptosis both in ECs and Macrophages. CONCLUSIONSHCC-1 expression markedly increased in patients with atherosclerosis and HCC-1 overexpression accelerated atherosclerotic burden via an enhancement in monocytes recruitment, M1 polarization and pyroptosis both in ECs and Macrophages. Our findings suggested that HCC-1 may serve as an early biomarker for the diagnosis of atherosclerosis, with the capacity to reflect the degree of stenosis. GRAPHIC ABSTRACTA graphic abstract is available for this article.

cell biology↗

Presynaptic reorganization in the sensory hair cell after noise exposure

In the mammalian cochlea, moderate acoustic overexposure leads to irreversible loss of ribbon-type synapse between sensory inner hair cell (IHC) and its postsynaptic auditory nerve fiber (ANF), causing a reduced dynamic range of hearing but not a permanently-elevated threshold. A prevailing view is that such ribbon loss (known as synaptopathy) selectively impacts those low-spontaneous-rate and high-threshold ANFs contacting predominantly the modiolar face of IHCs. However, the spatial pattern of synaptopathy remains scarce in the most sensitive mid-cochlear region, where long and short IHCs with distinct ribbon size gradients coexist. Here, we used volume electron microscopy to investigate noise exposure-related changes in the mouse IHCs with and without ribbon loss. Our quantifications reveal that the worst-hit areas of synaptopathy are the modiolar face of long IHCs and the pillar face of short IHCs. Moreover, we show relative enrichment of mitochondrial content in the survived ANF terminals, providing key experimental evidence for the long-proposed role of postsynaptic mitochondria in selective ribbon synapse degeneration following noise insult.

neuroscience↗

Who bears the load? IOP-induced collagen fiber recruitment over the corneoscleral shell

Collagen is the main load-bearing component of cornea and sclera. When stretched, both of these tissues exhibit a behavior known as collagen fiber recruitment. In recruitment, as the tissues stretch the constitutive collagen fibers lose their natural waviness, progressively straightening. Recruited, straight, fibers bear substantially more mechanical load than non-recruited, wavy, fibers. As such, the process of recruitment underlies the well-established nonlinear macroscopic behavior of the corneoscleral shell. Recruitment has an interesting implication: when recruitment is incomplete, only a fraction of the collagen fibers is actually contributing to bear the loads, with the rest remaining "in reserve". In other words, at a given intraocular pressure (IOP), it is possible that not all the collagen fibers of the cornea and sclera are actually contributing to bear the loads. To the best of our knowledge, the fraction of corneoscleral shell fibers recruited and contributing to bear the load of IOP has not been reported. Our goal was to obtain regionally-resolved estimates of the fraction of corneoscleral collagen fibers recruited and in reserve. We developed a fiber-based microstructural constitutive model that could account for collagen fiber undulations or crimp via their tortuosity. We used experimentally-measured collagen fiber crimp tortuosity distributions in human eyes to derive region-specific nonlinear hyperelastic mechanical properties. We then built a three-dimensional axisymmetric model of the globe, assigning region-specific mechanical properties and regional anisotropy. The model was used to simulate the IOP-induced shell deformation. The model-predicted tissue stretch was then used to quantify collagen recruitment within each shell region. The calculations showed that, at low IOPs, collagen fibers in the posterior equator were recruited the fastest, such that at a physiologic IOP of 15 mmHg, over 90% of fibers were recruited, compared with only a third in the cornea and the peripapillary sclera. The differences in recruitment between regions, in turn, mean that at a physiologic IOP the posterior equator had a fiber reserve of only 10%, whereas the cornea and peripapillary sclera had two thirds. At an elevated IOP of 50 mmHg, collagen fibers in the limbus and the anterior/posterior equator were almost fully recruited, compared with 90% in the cornea and the posterior sclera, and 70% in the peripapillary sclera and the equator. That even at such an elevated IOP not all the fibers were recruited suggests that there are likely other conditions that challenge the corneoscleral tissues even more than IOP. The fraction of fibers recruited may have other potential implications. For example, fibers that are not bearing loads may be more susceptible to enzymatic digestion or remodeling. Similarly, it may be possible to control tissue stiffness through the fraction of recruited fibers without the need to add or remove collagen.

bioengineering↗

Single-cell Transcriptomic Analysis of Systemic Autoinflammatory Diseases with Anti-TNFα Therapy

Systemic autoinflammatory diseases (SAIDs) are a group of rare diseases characterized by recurrent or continuous inflammation, typically accompanied by genetic variants. Good responses to anti-TNF therapy were observed in SAIDs patients. However, the mechanisms underlying the disease flare and the response to TNF blocking therapy have not been fully elucidated. Here, we use single-cell RNA sequencing technology to describe the transcriptomic profile of PBMCs and PMNs in SAIDs patients both before and after anti-TNF treatment. We found that interferon responses are involved in the active phase of the disease. After anti-TNF therapy, we observed remission from clinical symptoms while unexpected elevation of TNF and IL-1, indicating that these inflammatory cytokines are not positively correlated with disease activity. Trajectory analysis showed that inhibition of macrophage differentiation, rather than reduction of the inflammatory cytokines, as the potential mechanism of anti-TNF treatment response in SAIDs.

immunology↗

A direct fiber approach to model sclera collagen architecture and biomechanics

Sclera collagen fiber microstructure and mechanical behavior are central to eye physiology and pathology. They are also complex, and are therefore often studied using modeling. Most models of sclera, however, have been built within a conventional continuum framework. In this framework, collagen fibers are incorporated as statistical distributions of fiber characteristics such as the orientation of a family of fibers. The conventional continuum approach, while proven successful for describing the macroscale behavior of the sclera, does not account for the sclera fibers are long, interwoven and interact with one another. Hence, by not considering these potentially crucial characteristics, the conventional approach has only a limited ability to capture and describe sclera structure and mechanics at smaller, fiber-level, scales. Recent advances in the tools for characterizing sclera microarchitecture and mechanics bring to the forefront the need to develop more advanced modeling techniques that can incorporate and take advantage of the newly available highly detailed information. Our goal was to create a new computational modeling approach that can represent the sclera fibrous microstructure more accurately than with the conventional continuum approach, while still capturing its macroscale behavior. In this manuscript we introduce the new modeling approach, that we call direct fiber modeling, in which the collagen architecture is built explicitly by long, continuous, interwoven fibers. The fibers are embedded in a continuum matrix representing the non-fibrous tissue components. We demonstrate the approach by doing direct fiber modeling of a rectangular patch of posterior sclera. The model integrated fiber orientations obtained by polarized light microscopy from coronal and sagittal cryosections of pig and sheep. The fibers were modeled using a Mooney- Rivlin model, and the matrix using a Neo-Hookean model. The fiber parameters were determined by inversely matching experimental equi-biaxial tensile data from the literature. After reconstruction, the direct fiber model orientations agreed well with the microscopy data both in the coronal plane (adjusted R2=0.8234) and in the sagittal plane (adjusted R2=0.8495) of the sclera. With the estimated fiber properties (C10=5746.9 MPa; C01=-5002.6MPa, matrix shear modulus 200kPa), the models stress-strain curves simultaneously fit the experimental data in radial and circumferential directions (adjusted R2s 0.9971 and 0.9508, respectively). The estimated fiber elastic modulus at 2.16% strain was 5.45GPa, in reasonable agreement with the literature. During stretch, the model exhibited stresses and strains at sub-fiber level, with interactions among individual fibers which are not accounted for by the conventional continuum methods. Our results demonstrate that direct fiber models can simultaneously describe the macroscale mechanics and microarchitecture of the sclera, and therefore that the approach can provide unique insight into tissue behavior questions inaccessible with continuum approaches. HighlightsCollagen fibers are the main load-bearing component of eye tissues. Conventional sclera modeling ignores that fibers are long, interwoven and interact. We demonstrate a direct fiber model with long, interwoven and interacting fibers. Collagen fiber mechanical properties were estimated using inverse fitting. The model captures simultaneously sclera fiber structure and macroscale mechanics.

bioengineering↗

Comparing acute IOP-induced lamina cribrosa deformations pre-mortem and post-mortem

PurposeLamina cribrosa (LC) deformations caused by elevated intraocular pressure (IOP) are believed to contribute to glaucomatous neuropathy and have therefore been extensively studied, in many conditions from in-vivo to ex-vivo. We compare acute IOP-induced global and local LC deformations immediately before (pre-mortem) and after (post-mortem) sacrifice by exsanguination. MethodsThe optic nerve heads of three healthy monkeys 12-15 years old were imaged with spectral-domain optical coherence tomography under controlled IOP pre-mortem and post-mortem. Volume scans were acquired at baseline IOP (8-10 mmHg) and at 15, 30, and 40 mmHg IOP. A digital volume correlation technique was used to determine the IOP-induced 3D LC deformations (strains) in regions visible pre-mortem and post-mortem. ResultsBoth conditions exhibited similar nonlinear relationships between IOP increases and LC deformations. Median effective and shear strains were, on average over all eyes and pressures, smaller post-mortem than pre-mortem, by 14% and 11%, respectively (Ps < 0.001). Locally, however, the differences in LC deformation between conditions were variable. Some regions were subjected pre-mortem to triple the strains observed post-mortem, and others suffered smaller deformations pre-mortem than post-mortem. ConclusionsIncreasing IOP acutely caused nonlinear LC deformations with an overall smaller effect post-mortem than pre-mortem. Locally, deformations pre-mortem and post-mortem were sometimes substantially different. We suggest that the differences may be due to weakened mechanical support from the unpressurized central retinal vessels post-mortem. Translational RelevanceAdditional to the important pre-mortem information, comparison with post-mortem provides a unique context essential to understand the translational relevance of all post-mortem biomechanics literature. PrecisThe authors compared in monkeys acute IOP-induced deformations of the lamina cribrosa pre-mortem and post-mortem. Deformation trends were similar pre-mortem and post-mortem, but deformations pre-mortem were generally smaller than those post-mortem, with substantial local variations. The differences are likely due to loss of vessel support post-mortem.

bioengineering↗

ProSelfLC: Progressive Self Label Correction Towards A Low-Temperature Entropy State

To train robust deep neural networks (DNNs), we systematically study several target modification approaches, which include output regularisation, self and non-self label correction (LC). Three key issues are discovered: (1) Self LC is the most appealing as it exploits its own knowledge and requires no extra models. However, how to automatically decide the trust degree of a learner as training goes is not well answered in the literature. (2) Some methods penalise while the others reward low-entropy predictions, prompting us to ask which one is better. (3) Using the standard training setting, a trained network is of low confidence when severe noise exists, making it hard to leverage its high-entropy self knowledge. To resolve the issue (1), taking two well-accepted propositions-deep neural networks learn meaningful patterns before fitting noise and minimum entropy regularisation principle-we propose a novel end-to-end method named ProSelfLC, which is designed according to learning time and entropy. Specifically, given a data point, we progressively increase trust in its predicted label distribution versus its annotated one if a model has been trained for enough time and the prediction is of low entropy (high confidence). For the issue (2), according to ProSelfLC, we empirically prove that it is better to redefine a meaningful low-entropy status and optimise the learner toward it. This serves as a defence of entropy minimisation. To address the issue (3), we decrease the entropy of self knowledge using a low temperature before exploiting it to correct labels, so that the revised labels redefine a low-entropy target state. We demonstrate the effectiveness of ProSelfLC through extensive experiments in both clean and noisy settings, and on both image and protein datasets. Furthermore, our source code is available at https://github.com/XinshaoAmosWang/ProSelfLC-AT.

bioinformatics↗

Connectomic Analysis of Thalamus-driven Disinhibition in Cortical Layer 4

In mammals, sensory signals are transmitted via the thalamus primarily to layer 4 of the primary sensory cortices. While information about average neuronal connectivity in this layer is available, the detailed and higher-order circuit structure is not known. Here, we used 3-dimensional electron microscopy for a connectomic analysis of the thalamus-driven inhibitory network in a layer 4 barrel. We find that thalamic input drives a subset of interneurons with high specificity. These interneurons in turn target spiny stellate and star pyramidal excitatory neurons with subtype specificity. In addition, they create a directed disinhibitory network directly driven by the thalamic input. Together, this circuit can create differential windows of opportunity for activation of the types of excitatory neurons in dependence of strength and timing of thalamic input. With this, we have identified a so-far unknown degree of specialization of the microcircuitry in the main thalamocortical recipient layer of the primary sensory cortex.

neuroscience↗

A broad and potent neutralization epitope in SARS-related coronaviruses

Many neutralizing antibodies (nAbs) elicited to ancestral SARS-CoV-2 through natural infection and vaccination generally have reduced effectiveness to SARS-CoV-2 variants. Here we show therapeutic antibody ADG20 is able to neutralize all SARS-CoV-2 variants of concern (VOCs) including Omicron (B.1.1.529) as well as other SARS-related coronaviruses. We delineate the structural basis of this relatively escape-resistant epitope that extends from one end of the receptor binding site (RBS) into the highly conserved CR3022 site. ADG20 can then benefit from high potency through direct competition with ACE2 in the more variable RBS and interaction with the more highly conserved CR3022 site. Importantly, antibodies that are able to target this site generally neutralize all VOCs, albeit with reduced potency against Omicron. Thus, this highly conserved and vulnerable site can be exploited for design of universal vaccines and therapeutic antibodies.

microbiology↗

Anticancer immunotherapies transition postcapillary venules into high-endothelial venules that generate TCF1+ T lymphocyte niches through a feed-forward loop

The lack of T-cell infiltrates is a major obstacle to effective immunotherapy in cancer. Conversely, the formation of tumor-associated tertiary-lymphoid-like structures (TA-TLS), which are the local site of humoral and cellular immune responses against cancers, are associated with good prognosis and have recently been detected in Immune Checkpoint Blockade (ICB)-responding patients. However, how these lymphoid aggregates develop remains poorly understood. By employing scRNA sequencing, endothelial fate mapping, and functional multiplex immune profiling, we demonstrate that antiangiogenic immune-modulating therapies evoke the transition of postcapillary venules into inflamed high endothelial venules (HEVs), which generate permissive TA-TLS-like lymphocyte niches with PD1neg and PD1+TCF1+CD8 T cell progenitors that differentiate into GrzB+TCF1neg TIM3+ PD1+ CD8 T effector cells. Tumor-HEVs require continuous CD8 and NK cell-derived lymphotoxin signals revealing that tumor-HEV maintenance is actively sculpted by the adaptive immune system through a feed-forward loop. In BriefHua & Vella et al. reveal that effective antiangiogenic immunotherapy transitions postcapillary venules into inflamed high-endothelial venules (HEV), sustained by CD8 T and NK cell-derived signals through a feed-forward loop. Thereby, tumoral HEVs establish perivascular niches in which TCF1+ PD1+ lymphocytes expand and produce cytolytic PD1+ TIM3+ CD8 T cells that facilitate anti-tumoral immunity. HighlightsO_LIHigh endothelial venule induction by anticancer immunotherapies generates perivascular immune niches permissive for TCF1+ PD1+ CD8 progenitor T cell expansion and production of TCF1neg PD1+ TIM3+ CD8 effector T cells C_LIO_LITumoral high-endothelial venules exhibit characteristics of inflamed lymph node HEVs and postcapillary venules C_LIO_LIPostcapillary venules dynamically transdifferentiate into high-endothelial venules in tumors, which requires continuous signals from surrounding immune cells C_LIO_LICD8 and NK cells drive tumoral high-endothelial venule formation during antiangiogenic immunotherapies in a feed-forward loop via lymphotoxin beta receptor signaling C_LI

cancer biology↗

Real-time imaging of optic nerve head collagen microstructure and biomechanics using instant polarized light microscopy

Current tools lack the temporal or spatial resolution necessary to image many important aspects of the architecture and dynamics of the optic nerve head (ONH). We evaluated the potential of instant polarized light microscopy (IPOL) to overcome these limitations by leveraging the ability to capture collagen fiber orientation and density in a single image. Coronal sections through the ONH of fresh normal sheep eyes were imaged using IPOL while they were stretched using custom uniaxial or biaxial micro-stretch devices. IPOL allows identifying ONH collagen architectural details, such as fiber interweaving and crimp, and has high temporal resolution, limited only by the frame rate of the camera. Local collagen fiber orientations and deformations were quantified using color analysis and image tracking techniques. We quantified stretch-induced collagen uncrimping of lamina cribrosa (LC) and peripapillary sclera (PPS), and changes in LC pore size (area) and shape (convexity and aspect ratio). The simultaneous high spatial and temporal resolutions of IPOL revealed complex ONH biomechanics: i) stretch-induced local deformation of the PPS was nonlinear and nonaffine. ii) under load the crimped collagen fibers in the PPS and LC straightened, without torsion and with only small rotations. iii) stretch-induced LC pore deformation was anisotropic and heterogeneous among pores. Overall, with stretch the pores were became larger, more convex, and more circular. We have demonstrated that IPOL reveals details of collagen morphology and mechanics under dynamic loading previously out of reach. IPOL can detect stretch-induced collagen uncrimping and other elements of the tissue nonlinear mechanical behavior. IPOL showed changes in pore morphology and collagen architecture that will help improve understanding of how LC tissue responds to load. HighlightsO_LIWe demonstrate that instant polarized light microscopy allows visualization and quantification of changes in optic nerve head collagen morphology and architecture under dynamic loading C_LIO_LIWe show crimped collagen fibers in the peripapillary sclera and lamina cribrosa straightening under load, without torsion and with only small rotations. C_LIO_LIWe show that stretch-induced local deformation of the peripapillary sclera was nonlinear and nonaffine. C_LIO_LIWe show that stretch-induced lamina cribrosa pore deformation was anisotropic and heterogeneous among pores. C_LIO_LIOur results show this novel imaging technique could help understand the role of collagen microstructure in eye physiology, aging, and in biomechanics-related diseases, such as glaucoma and myopia. C_LI

bioengineering↗

SARS-CoV-2 Beta variant infection elicits potent lineage-specific and cross-reactive antibodies

SARS-CoV-2 Beta variant of concern (VOC) resists neutralization by major classes of antibodies from non-VOC COVID-19 patients and vaccinated individuals. Here, serum of Beta variant infected patients revealed reduced cross-neutralization of non-VOC virus. From these patients, we isolated Beta-specific and cross-reactive receptor-binding domain (RBD) antibodies. The Beta-specificity results from recruitment of novel VOC-specific clonotypes and accommodation of VOC-defining amino acids into a major non-VOC antibody class that is normally sensitive to these mutations. The Beta-elicited cross-reactive antibodies share genetic and structural features with non-VOC-elicited antibodies, including a public VH1-58 clonotype targeting the RBD ridge independent of VOC mutations. These findings advance our understanding of the antibody response to SARS-CoV-2 shaped by antigenic drift with implications for design of next-generation vaccines and therapeutics. One sentence summarySARS-CoV-2 Beta variant elicits lineage-specific antibodies and antibodies with neutralizing breadth against wild-type virus and VOCs.

immunology↗

Screening of cell-virus, cell-cell, gene-gene interactions among kingdoms of life at single cell resolution

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) issued a significant and urgent threat to global health. The exact animal origin of SARS-CoV-2 remains obscure and understanding its host range is vital for preventing interspecies transmission. Previously, we have assessed the target cell profiles of SARS-CoV-2 in pets, livestock, poultry and wild animals. Herein, we expand this investigation to a wider range of animal species and viruses to provide a comprehensive source for large-scale screening of potential virus hosts. Single cell atlas for several mammalian species (alpaca, hamster, hedgehog, chinchilla etc.), as well as comparative atlas for lung, brain and peripheral blood mononuclear cells (PBMC) for various lineages of animals were constructed, from which we systemically analyzed the virus entry factors for 113 viruses over 20 species from mammalians, birds, reptiles, amphibians and invertebrates. Conserved cellular connectomes and regulomes were also identified, revealing the fundamental cell-cell and gene-gene cross-talks between these species. Overall, our study could help identify the potential host range and tissue tropism of SARS-CoV-2 and a diverse set of viruses and reveal the host-virus co-evolution footprints.

cell biology↗

A high-accuracy and high-efficiency digital volume correlation method to characterize in-vivo optic nerve head biomechanics from optical coherence tomography

In-vivo optic nerve head (ONH) biomechanics characterization is emerging as a promising way to study eye physiology and pathology. We propose a high-accuracy and high-efficiency digital volume correlation (DVC) method for the purpose of characterizing the in-vivo ONH deformation from volumes acquired by optical coherence tomography (OCT). Using a combination of synthetic tests and analysis of OCTs from monkey ONHs subjected to acute and chronically elevated intraocular pressure, we demonstrate that our proposed methodology overcomes several challenges for conventional DVC methods. First, it accounts for large ONH rigid body motion in the OCT volumes which could otherwise lead to analysis failure; second, sub-voxel-accuracy displacement can be guaranteed despite high noise and low image contrast of some OCT volumes; third, computational efficiency is greatly improved, such that the memory consumption of our method is substantially lower than with conventional methods; fourth, we introduce a parameter measuring displacements confidence. Test of image noise effects showed that the proposed DVC method had displacement errors smaller than 0.028 voxels with speckle noise and smaller than 0.037 voxels with Gaussian noise; The absolute (relative) strain errors in the three directions were lower than 0.0018 (4%) with speckle noise and than 0.0045 (8%) with Gaussian noise. Compared with conventional DVC methods, the proposed DVC method had substantially improved overall displacement and strain errors under large body motions (lower by up to 70%), with 75% lower computation times, while saving about 30% memory. The study thus demonstrates the potential of the proposed technique to investigate ONH biomechanics.

bioengineering↗

Viral receptor profiles of masked palm civet revealed by single-cell transcriptomics

Civets are small mammals belonging to the family Viverridae. The masked palm civets (Paguma larvata) served as an intermediate host in the bat-to-human transmission of severe acute respiratory syndrome coronavirus (SARS-CoV) in 20031. Because of their unique role in the SARS outbreak, civets were suspected as a potential intermediate host of SARS-CoV-2, the etiological pathogen of the COVID-19 pandemic. Besides their susceptibility to coronaviruses, civets can also be infected by other viruses, such as canine distemper viruses2, parvoviruses3, influenza viruses4, etc. Regarding the ecological and economical role of civets, it is vital to evaluate the potential threats from different pathogens to these animals. Receptor binding is a necessary step for virus entry into host cells. Understanding the distribution of receptors of various viruses provides hints to their potential tissue tropisms. Herein, we characterized the cell atlas of five important organs (the frontal lobe, lung, liver, spleen and kidney) of masked palm civets (Paguma larvata) and described the expression profiles of receptor associated genes of 132 viruses from 25 families, including 16 viruses from 10 families reported before that can attack civets and 116 viruses with little infection record.

immunology↗