Biology subjects

Byun, S. Y.

Publications and source records attributed to Byun, S. Y..

4 recordsLinked to original sources

bioRxiv2021

Analysis of B-cell receptor repertoires in COVID-19 patients using deep embedded representations of protein sequences

Analyzing B cell receptor (BCR) repertoires is immensely useful in evaluating ones immunological status. Conventionally, repertoire analysis methods have focused on comprehensive assessments of clonal compositions, including V(D)J segment usage, nucleotide insertions/deletions, and amino acid distributions. Here, we introduce a novel computational approach that applies deep-learning-based protein embedding techniques to analyze BCR repertoires. By selecting the most frequently occurring BCR sequences in a given repertoire and computing the sum of the vector representations of these sequences, we represent an entire repertoire as a 100-dimensional vector and eventually as a single data point in vector space. We demonstrate that this new approach enables us to not only accurately cluster BCR repertoires of coronavirus disease 2019 (COVID-19) patients and healthy subjects but also efficiently track minute changes in immune status over time as patients undergo treatment. Furthermore, using the distributed representations, we successfully trained an XGBoost classification model that achieved a mean accuracy rate of over 87% given a repertoire of CDR3 sequences.

bioinformatics↗

bioRxiv2020

Non-canonical immune response to the inhibition of DNA methylation via stabilization of endogenous retrovirus dsRNAs

5-Aza-2'-deoxycytidine, also known as decitabine, is a DNA-methyltransferase inhibitor (DNMTi) used to treat acute myeloid leukemia (AML). Decitabine activates the transcription of endogenous retroviruses (ERV), which can induce an immune response by acting as cellular double-stranded RNAs (dsRNAs). Here, we employ an image-based screening platform to identify dsRNA-binding factors that mediate the downstream effect of ERV induction. We find that Staufen1 (Stau1) knockdown decreases the interferon signature and rescues decitabine-mediated cell death. Moreover, Stau1 directly binds to ERV RNAs and stabilizes them, together with a long non-coding RNA TINCR. We further show that TINCR enhances the interaction between Stau1 and ERV RNAs. Analysis of a clinical patient cohort reveals that AML patients with low Stau1 and TINCR expressions exhibits inferior treatment outcomes to the DNMTi therapy. Our study reveals that decitabine-mediated cell death is a consequence of complex interactions among different dsRNA-binding proteins for access to their common dsRNA targets. HIGHLIHGTSO_LIImage-based RNAi screening reveals multiple dsRBPs regulate response to decitabine C_LIO_LIStau1 binds to ERV RNAs and affects their stability and subcellular localization C_LIO_LITINCR binds to Stau1 and enhances Stau1-ERV interactions C_LIO_LIAML/MDS patients with low Stau1 and TINCR expressions show poor response to DNMTis C_LI

molecular biology↗

bioRxiv2020

Identification of antiviral drug candidates against SARS-CoV-2 from FDA-approved drugs

COVID-19 is an emerging infectious disease and was recently declared as a pandemic by WHO. Currently, there is no vaccine or therapeutic available for this disease. Drug repositioning represents the only feasible option to address this global challenge and a panel of 48 FDA-approved drugs that have been pre-selected by an assay of SARS-CoV was screened to identify potential antiviral drug candidates against SARS-CoV-2 infection. We found a total of 24 drugs which exhibited antiviral efficacy (0.1 M < IC50 < 10 M) against SARS-CoV-2. In particular, two FDA-approved drugs - niclosamide and ciclesonide - were notable in some respects. These drugs will be tested in an appropriate animal model for their antiviral activities. In near future, these already FDA-approved drugs could be further developed following clinical trials in order to provide additional therapeutic options for patients with COVID-19.

microbiology↗

bioRxiv2020

Screening of FDA-approved drugs using a MERS-CoV clinical isolate from South Korea identifies potential therapeutic options for COVID-19

Therapeutic options for coronavirus remain limited. To address this unmet medical need, we screened 5,406 compounds, including United States Food and Drug Administration (FDA)- approved drugs and bioactives, for activity against a South Korean Middle East respiratory syndrome coronavirus (MERS-CoV) clinical isolate. Among 221 identified hits, 54 had therapeutic indexes (TI) greater than 6. Time-of-addition studies with selected drugs demonstrated eight and four FDA-approved drugs acted on the early and late stages of the viral life cycle, respectively. Confirmed hits included several cardiotonic agents (TI>100), atovaquone, an anti-malarial (TI>34), and ciclosonide, an inhalable corticosteroid (TI>6). Furthermore, utilizing the severe acute respiratory syndrome CoV-2 (SARS-CoV-2), combinations of remedesivir with selected dugs were evaluated, which identified ciclosonide and nelfinavir to be additive and synergistic drugs in vitro, respectively. Together, we screened FDA-approved drugs using patient-derived MERS-CoV, triaged hits to discriminate between early and late viral life cycle inhibitors, confirmed selected drugs using SARS-CoV-2, and demonstrated the added value of selected medications in combination with remedesivir. Our results identify potential therapeutic options for MERS-CoV infections, and provide a basis to treat coronavirus disease 2019 (COVID-19) and other coronavirus-related illnesses.

microbiology↗