28 research outputs found

    Deep Sequencing of B Cell Receptor Repertoires From COVID-19 Patients Reveals Strong Convergent Immune Signatures.

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    Deep sequencing of B cell receptor (BCR) heavy chains from a cohort of 31 COVID-19 patients from the UK reveals a stereotypical naive immune response to SARS-CoV-2 which is consistent across patients. Clonal expansion of the B cell population is also observed and may be the result of memory bystander effects. There was a strong convergent sequence signature across patients, and we identified 1,254 clonotypes convergent between at least four of the COVID-19 patients, but not present in healthy controls or individuals following seasonal influenza vaccination. A subset of the convergent clonotypes were homologous to known SARS and SARS-CoV-2 spike protein neutralizing antibodies. Convergence was also demonstrated across wide geographies by comparison of data sets between patients from UK, USA, and China, further validating the disease association and consistency of the stereotypical immune response even at the sequence level. These convergent clonotypes provide a resource to identify potential therapeutic and prophylactic antibodies and demonstrate the potential of BCR profiling as a tool to help understand patient responses

    Unlocking saponin biosynthesis in soapwort

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    Soapwort (Saponaria officinalis) is a flowering plant from the Caryophyllaceae family with a long history of human use as a traditional source of soap. Its detergent properties are because of the production of polar compounds (saponins), of which the oleanane-based triterpenoid saponins, saponariosides A and B, are the major components. Soapwort saponins have anticancer properties and are also of interest as endosomal escape enhancers for targeted tumor therapies. Intriguingly, these saponins share common structural features with the vaccine adjuvant QS-21 and, thus, represent a potential alternative supply of saponin adjuvant precursors. Here, we sequence the S. officinalis genome and, through genome mining and combinatorial expression, identify 14 enzymes that complete the biosynthetic pathway to saponarioside B. These enzymes include a noncanonical cytosolic GH1 (glycoside hydrolase family 1) transglycosidase required for the addition of d-quinovose. Our results open avenues for accessing and engineering natural and new-to-nature pharmaceuticals, drug delivery agents and potential immunostimulants

    Arabidopsis CaM Binding Protein CBP60g Contributes to MAMP-Induced SA Accumulation and Is Involved in Disease Resistance against Pseudomonas syringae

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    Salicylic acid (SA)-induced defense responses are important factors during effector triggered immunity and microbe-associated molecular pattern (MAMP)-induced immunity in plants. This article presents evidence that a member of the Arabidopsis CBP60 gene family, CBP60g, contributes to MAMP-triggered SA accumulation. CBP60g is inducible by both pathogen and MAMP treatments. Pseudomonas syringae growth is enhanced in cbp60g mutants. Expression profiles of a cbp60g mutant after MAMP treatment are similar to those of sid2 and pad4, suggesting a defect in SA signaling. Accordingly, cbp60g mutants accumulate less SA when treated with the MAMP flg22 or a P. syringae hrcC strain that activates MAMP signaling. MAMP-induced production of reactive oxygen species and callose deposition are unaffected in cbp60g mutants. CBP60g is a calmodulin-binding protein with a calmodulin-binding domain located near the N-terminus. Calmodulin binding is dependent on Ca2+. Mutations in CBP60g that abolish calmodulin binding prevent complementation of the SA production and bacterial growth defects of cbp60g mutants, indicating that calmodulin binding is essential for the function of CBP60g in defense signaling. These studies show that CBP60g constitutes a Ca2+ link between MAMP recognition and SA accumulation that is important for resistance to P. syringae

    Standards for plant synthetic biology: a common syntax for exchange of DNA parts.

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    Inventors in the field of mechanical and electronic engineering can access multitudes of components and, thanks to standardization, parts from different manufacturers can be used in combination with each other. The introduction of BioBrick standards for the assembly of characterized DNA sequences was a landmark in microbial engineering, shaping the field of synthetic biology. Here, we describe a standard for Type IIS restriction endonuclease-mediated assembly, defining a common syntax of 12 fusion sites to enable the facile assembly of eukaryotic transcriptional units. This standard has been developed and agreed by representatives and leaders of the international plant science and synthetic biology communities, including inventors, developers and adopters of Type IIS cloning methods. Our vision is of an extensive catalogue of standardized, characterized DNA parts that will accelerate plant bioengineering.Biotechnological and Biological Sciences Research Council (BBSRC). Grant Numbers: BB/K005952/1, BB/L02182X/1 Synthetic Biology Research Centre ‘OpenPlant’ award. Grant Number: BB/L014130/1 Spanish MINECO. Grant Number: BIO2013‐42193‐R Engineering Nitrogen Symbiosis for Africa (ENSA) The Bill & Melinda Gates Foundation US Department of Energy, Office of Biological and Environmental. Grant Number: DE‐AC02‐05CH1123 COST Action. Grant Number: FA100

    Directed selection of MIP-1 alpha neutralizing CCR5 antibodies from a phage display human antibody library.

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    The seven trans-membrane chemokine receptor CCR-5 is a coreceptor for macrophage tropic HIV-1 strains. CCR-5 responds to a number of chemokines, including macrophage inflammatory protein (MIP)-1 alpha. We describe the use of MIP-1 alpha in a biotin tyramine-mediated proximity selection to guide the selection of CCR-5-specific phage antibodies from a large phage display human library. Proximity based selections resulted in a population of antibodies recognizing CCR-5 on primary CD4+ lymphocytes, none of which blocked MIP-1 alpha binding to cells. The selected population of phage antibodies were subsequently used as guide molecules for a second phase of selection that was carried out in the absence of MIP-1 alpha. This generated a panel of CCR-5-binding antibodies, of which around 20% inhibited MIP-1 alpha binding to CD4+. The single chain Fvs (scFv) generated by this step-back selection procedure also inhibited MIP-1 alpha-mediated calcium signaling.Journal Articleinfo:eu-repo/semantics/publishe
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