Biology subjects

Lennon, C.

Publications and source records attributed to Lennon, C..

4 recordsLinked to original sources

bioRxiv2024

Simple recombinant monoclonal antibody production from E. coli.

AO_SCPLOWBSTRACTC_SCPLOWAntibodies are valuable biological reagents used in a wide range of discovery research, biotechnology, diagnostic and therapeutic applications. Currently both commercial and lab scale antibody production is reliant on expression from mammalian cells, which can be time consuming and requires use of specialist facilities and costly growth reagents. Here we describe a simple, rapid and cheap method for producing and isolating functional monoclonal antibodies and antibody fragments from bacterial cells that can be used in a range of laboratory applications. This simple method only requires access to basic microbial cell culture and molecular biology equipment, making scalable in-house antibody production accessible to the global diagnostics, therapeutics and molecular bioscience research communities.

molecular biology↗

bioRxiv2023

Transcriptome-wide meta-analysis of codon usage in Escherichia coli

The preference for synonymous codons, termed codon usage bias (CUB), is a fundamental feature of coding sequences, with distinct preferences being observed across species, genomes and genes. Accurately quantifying codon usage frequencies is useful for a range of applications, from guiding mRNA vaccine design, to elucidating protein folding and uncovering co-evolutionary relationships. However, current methods are either based on a single genome assembly, lack functional stratification, or are extremely outdated. To address this, we adopted a data-driven approach and developed Codon Usage Bias estimation from RNA-sequencing data (CUBSEQ), a fully automatic meta-analysis pipeline to estimate CUB at the trascriptome-level and for gene panels. Here, we used CUBSEQ to perform, to our knowledge, the largest and most comprehensive CUB analysis of the transcriptome and highly expressed genes in Escherichia coli, using RNA sequencing data from 6,763 samples across 72 strains. By capturing sequence variants of these genes through variant calls, we constructed a per-sample representation of the E. coli transcriptome revealing a rich mutational landscape. We then identified a set of 81 highly expressed genes with consistent expression patterns across strains, sample library size and experimental conditions, and found significant differences in CUB compared to transcriptome-wide genes and alternative codon usage tables. Finally, we found codons with a high relative frequency were often associated with a larger repertoire of isoaccepting tRNAs and not necessarily high tRNA abundance.

genomics↗

bioRxiv2022

Exceptional yield vesicle packaged recombinant protein production from E. coli.

We describe a novel system that exports diverse recombinant proteins in extracellular vesicles from E. coli. The vesicles not only compartmentalise toxic, insoluble and disulphide bond containing proteins in a soluble and functional form (e.g. DNaseI, nanobodies and IgG-fusions), but the continued release of the inducible vesicle packaged proteins into the media supports continuous isolation of protein from active culture within a micro-environment allowing stable long-term storage. This technology results in unprecedented yields of vesicle packaged functional proteins for efficient downstream processing for a wide range of applications from discovery science to applied biotechnology and medicine.

molecular biology↗

bioRxiv2020

High mannose N-glycans on red blood cells as phagocytic ligands, mediating both sickle cell anaemia and resistance to malaria

In both sickle cell disease (SCD) and malaria, red blood cells (RBCs) are phagocytosed in the spleen, but receptor-ligand pairs mediating uptake have not been identified. Here, we report that patches of high mannose N-glycans (Man5-9GlcNAc2), expressed on diseased or oxidized RBC surfaces, bind the mannose receptor (CD206) on phagocytes to mediate clearance. Extravascular haemolysis in SCD correlates with high mannose glycan levels on RBCs. Infection of RBCs with Plasmodium falciparum expose surface mannose N-glycans on healthy RBCs, which occurred at significantly higher levels on RBCs from subjects with sickle cell trait compared to those lacking haemoglobin S. The glycans were associated with high molecular weight complexes and protease-resistant, lower molecular weight fragments containing spectrin. Recognition of surface N-linked high mannose glycans, a novel response to cellular stress, is the first molecular mechanism common to both the pathogenesis of SCD and resistance to severe malaria in sickle cell trait.

immunology↗