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Biology subjects

Limaye, A.

Publications and source records attributed to Limaye, A..

4 recordsLinked to original sources

Unconventional linkers facilitate potent stabilized coronavirus stem antibody responses following nanoparticle vaccination

Vaccine technologies that protect against a range of related pathogens within viral families, such as human immunodeficiency virus (HIV), influenza, and coronaviruses (CoVs) represent the future of viral vaccine development. Towards developing broad-spectrum CoV and influenza vaccines, we and others previously designed and evaluated CoV and influenza stem antigens; but these elicited relatively weak and sub-neutralizing antibody (Ab) responses. Multivalent antigen display on nanoparticles (NPs) is an established strategy to enhance and shape immunogenicity. However, one facet of NP vaccines has been largely overlooked: the indispensable linker segment between the antigen and NP core. Here, we introduce de novo-designed rigid (L2) and rarely used long flexible (L6) linkers to optimally display antigens on NPs, target occluded epitopes, and enhance cross-reactive Ab responses, using prefusion-stabilized Middle East respiratory syndrome coronavirus (MERS-CoV) spike (S-2P) and stem (SS) antigens as prototype antigens. Antigenic characterization of L2-NPs confirmed enhanced Ab binding and exposure of cross-reactive epitopes compared with L6-NPs and soluble antigens. Immunization with SS-L2-NPs elicited broader, more potent cross-reactive Ab responses across the seven human-infecting CoVs and pandemic threat WIV1-CoV, whereas SS-L6-NPs induced stronger neutralizing Ab responses against MERS-CoV, SARS-CoV-2, and WIV1-CoV. Ab competition and systems serology analyses revealed that SS-L2-NPs elicit robust Fc-mediated effector functions. By improving CoV-targeting Ab functionality, these linker approaches have the potential to confer broad-spectrum CoV protection and represent a promising strategy against hypervariable influenza and HIV viruses - as well as other broad viral families with pandemic potential.

bioengineering↗

Systematic discovery and functional interrogation of SARS-CoV-2 viral RNA-host protein interactions during infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a pandemic with growing global mortality. There is an urgent need to understand the molecular pathways required for host infection and anti-viral immunity. Using comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS), we identified 309 host proteins that bind the SARS-CoV-2 RNA during active infection. Integration of this data with viral ChIRP-MS data from three other positive-sense RNA viruses defined pan-viral and SARS-CoV-2-specific host interactions. Functional interrogation of these factors with a genome-wide CRISPR screen revealed that the vast majority of viral RNA-binding proteins protect the host from virus-induced cell death, and we identified known and novel anti-viral proteins that regulate SARS-CoV-2 pathogenicity. Finally, our RNA-centric approach demonstrated a physical connection between SARS-CoV-2 RNA and host mitochondria, which we validated with functional and electron microscopy data, providing new insights into a more general virus-specific protein logic for mitochondrial interactions. Altogether, these data provide a comprehensive catalogue of SARS-CoV-2 RNA-host protein interactions, which may inform future studies to understand the mechanisms of viral pathogenesis, as well as nominate host pathways that could be targeted for therapeutic benefit. Highlights{middle dot} ChIRP-MS of SARS-CoV-2 RNA identifies a comprehensive viral RNA-host protein interaction network during infection across two species {middle dot} Comparison to RNA-protein interaction networks with Zika virus, dengue virus, and rhinovirus identify SARS-CoV-2-specific and pan-viral RNA protein complexes and highlights distinct intracellular trafficking pathways {middle dot} Intersection of ChIRP-MS and genome-wide CRISPR screens identify novel SARS-CoV-2-binding proteins with pro- and anti-viral function {middle dot} Viral RNA-RNA and RNA-protein interactions reveal specific SARS-CoV-2-mediated mitochondrial dysfunction during infection

microbiology↗

A spark of 3D revisualization: new method for re-exploring segmented data

3D scientific visualization is a popular non-destructive investigation tool, however current imaging processing and 3D visualization software has compatibility barriers which make replicability and reproducibility in research difficult. To solve this, we developed a new revisualization method and demonstrated four case studies using three mainstream image processing and 3D visualization software. Our method offers interchangeability amongst current image processing and 3D visualization software.

evolutionary biology↗

A new tool for 3D segmentation of computed tomography data: Drishti Paint and its applications

Computational tomography is more and more widely used in many fields for its non-destructive and high-resolution in detecting internal structures of the samples. 3D segmentation of computed tomography data, which sheds light into internal features of target objects, is increasingly gaining in importance. However, how to efficiently and precisely reconstruct computed tomography data and better represent the data remains a hassle. Here, using a set of scan data of a fossil fish as a case study, we present a new release of open-source volume exploration, rendering, and 3D segmentation software, Drishti v2.6.6, and its protocol for performing 3D segmentation and other advanced applications. We provide new toolsets and workflow to segment computed tomography data thus benefit the scientific community with more accurate and precise digital reconstruction, 3D modelling and 3D printing results. Our procedure is widely applicable not only in palaeontology, but also in biological, medical, and industrial researches, and can be used as a framework to segment computed tomography and other forms of volumetric data from any research field.

evolutionary biology↗