Biology subjects

Schwabe, N. F.

Publications and source records attributed to Schwabe, N. F..

2 recordsLinked to original sources

bioRxiv2024

Functional Activity and Binding Specificity of small Ankyron Repeat Proteins against SARS-CoV-2 variants

Effective management of COVID-19 requires clinical tools to treat the disease in addition to preventive vaccines. Several recombinant mAbs and their cocktails have been developed to treat COVID-19 but these have limitations. Here, we evaluate small ankyrin repeat proteins called Ankyrons that were generated to bind with high affinity to the SARS-CoV-2 virus. Ankyrons are ankyrin repeat proteins comprised of repetitions a structural module. Each module consists of a {beta}-turn followed by two antiparallel -helices. The Ankyrons are directly selected in vitro from a highly diverse library of around a trillion clones in ribosome display and like antibodies can bind with high affinity to almost any target. We assessed Ankyrons that were generated against the wild-type SARS-CoV-2 and the Delta and Omicron variants in a binding assay. We determined that all Ankyrons were specific in that they did not bind to MERS, a related coronavirus. While all Ankyrons bound with high affinity to the variant they were generated against, some also showed cross-reactivity to all three SARS-CoV-2 variants. Binding assays are useful for screening analytes but do not provide information about clinical effectiveness. Therefore, we used a pseudovirus-based neutralization assay to show that five of the Ankyrons evaluated neutralized all three strains of SARS-CoV-2. We have provided a workflow for the evaluation of novel Ankyrons against a viral target. This suggests that Ankyrons could be useful for rapidly developing new research tools for studying other emerging infectious diseases rapidly with the optional further potential for developing Ankyrons into diagnostic and even therapeutic applications. Author SummaryYun-Jong Park: Investigation, Methodology, Format Analysis, Writing - original draft. Wojciech Jankowski: Methodology, Format Analysis, and Review. Nicholas C Hurst, Jeremy W Fry, Nikolai F Schwabe and Linda C C Tan: Resources, Review & Editing. Zuben E Sauna: Conceptualization, Supervision, Writing - original draft and Final editing.

immunology↗

bioRxiv2020

Broad and strong memory CD4+ and CD8+ T cells induced by SARS-CoV-2 in UK convalescent COVID-19 patients.

COVID-19 is an ongoing global crisis in which the development of effective vaccines and therapeutics will depend critically on understanding the natural immunity to the virus, including the role of SARS-CoV-2-specific T cells. We have conducted a study of 42 patients following recovery from COVID-19, including 28 mild and 14 severe cases, comparing their T cell responses to those of 16 control donors. We assessed the immune memory of T cell responses using IFN{gamma} based assays with overlapping peptides spanning SARS-CoV-2 apart from ORF1. We found the breadth, magnitude and frequency of memory T cell responses from COVID-19 were significantly higher in severe compared to mild COVID-19 cases, and this effect was most marked in response to spike, membrane, and ORF3a proteins. Total and spike-specific T cell responses correlated with the anti-Spike, anti-Receptor Binding Domain (RBD) as well as anti-Nucleoprotein (NP) endpoint antibody titre (p<0.001, <0.001 and =0.002). We identified 39 separate peptides containing CD4+ and/or CD8+ epitopes, which strikingly included six immunodominant epitope clusters targeted by T cells in many donors, including 3 clusters in spike (recognised by 29%, 24%, 18% donors), two in the membrane protein (M, 32%, 47%) and one in the nucleoprotein (Np, 35%). CD8+ responses were further defined for their HLA restriction, including B*4001-restricted T cells showing central memory and effector memory phenotype. In mild cases, higher frequencies of multi-cytokine producing M- and NP-specific CD8+ T cells than spike-specific CD8+ T cells were observed. They furthermore showed a higher ratio of SARS-CoV-2-specific CD8+ to CD4+ T cell responses. Immunodominant epitope clusters and peptides containing T cell epitopes identified in this study will provide critical tools to study the role of virus-specific T cells in control and resolution of SARS-CoV-2 infections. The identification of T cell specificity and functionality associated with milder disease, highlights the potential importance of including non-spike proteins within future COVID-19 vaccine design.

immunology↗