Biology subjects

Bagdonaite, I.

Publications and source records attributed to Bagdonaite, I..

4 recordsLinked to original sources

bioRxiv2022

Glycoengineered keratinocyte library reveals essential functions of specific glycans for all stages of HSV-1 life cycle

Viral and host glycans represent an understudied aspect of host-pathogen interactions, despite potential implications for treatment of viral infections. This is due to lack of easily accessible tools for analyzing glycan function in a meaningful context. Here we generated a glycoengineered keratinocyte library delineating human glycosylation pathways to uncover roles of specific glycans at different stages of herpes simplex virus type 1 (HSV-1) infectious cycle. We show the importance of cellular glycosaminoglycans and glycosphingolipids for HSV-1 attachment, N-glycans for entry and spread, and O-glycans for propagation. While altered virion surface structures had minimal effects on the early interactions with wild type cells, mutation of specific O-glycosylation sites affected glycoprotein surface expression and function. In conclusion, the data demonstrates the importance of specific glycans in a clinically relevant human model of HSV-1 infection and highlights the utility of genetic engineering to elucidate the roles of specific viral and cellular carbohydrate structures.

microbiology↗

bioRxiv2022

Isoform-specific O-glycosylation dictates Ebola virus infectivity

Ebola virus glycoprotein is one of the most heavily O-glycosylated viral envelope glycoproteins. Using glycoengineered cell lines we demonstrate that O-linked glycan truncation and perturbed initiation retarded the production of viral particles and decreased infectivity of progeny virus. Next, using TMT isobaric labelling, we performed quantitative differential O-glycoproteomics on proteins produced in wild type HEK293 cells and cell lines ablated for three key GalNAc-transferases, GalNAc-T1, -T2, and -T3, as well as compared it to patterns on wild type virus-like particles. We demonstrate selective initiation of a subset of O-glycosites by each enzyme, with GalNAc-T1 having the largest contribution. This work represents a comprehensive site-specific analysis of EBOV GP, with 47 O-glycosites identified, and sheds light on differential regulation of EBOV GP glycosylation initiated by host GalNAc-Ts. Together with the effect on viral propagation it opens prospective avenues for tailored intervention approaches and means for modulating immunogen O-glycan density.

microbiology↗

bioRxiv2021

Site-specific O-glycosylation analysis of SARS-CoV-2 spike protein produced in insect and human cells

Enveloped viruses hijack not only the host translation processes, but also its glycosylation machinery, and to a variable extent cover viral surface proteins with tolerogenic host-like structures. SARS-CoV-2 surface protein S presents as a trimer on the viral surface and is covered by a dense shield of N-linked glycans, and a few O-glycosites have been reported. The location of O-glycans is controlled by a large family of initiating enzymes with variable expression in cells and tissues and hence difficult to predict. Here, we used our well-established O-glycoproteomic workflows to map the precise positions of O-linked glycosylation sites on three different entities of protein S - insect cell or human cell-produced ectodomains, or insect cell derived receptor binding domain (RBD). In total 25 O-glycosites were identified, with similar patterns in the two ectodomains of different cell origin, and a distinct pattern of the monomeric RBD. Strikingly, 16 out of 25 O-glycosites were located within three amino acids from known N-glycosites. However, O-glycosylation was primarily found on peptides that were unoccupied by N-glycans, and otherwise had low overall occupancy. This suggests possible complementary functions of O-glycans in immune shielding and negligible effects of O-glycosylation on subunit vaccine design for SARS-CoV-2.

molecular biology↗

bioRxiv2021

The hyperlipidaemic drug fenofibrate significantly reduces infection by SARS-CoV-2 in cell culture models

The SARS-CoV-2 pandemic has caused a significant number of fatalities and worldwide disruption. To identify drugs to repurpose to treat SARS-CoV-2 infections, we established a screen to measure dimerization of ACE2, the primary receptor for the virus. This screen identified fenofibric acid, the active metabolite of fenofibrate. Fenofibric acid also destabilized the receptor binding domain (RBD) of the viral spike protein and inhibited RBD binding to ACE2 in ELISA and whole cell binding assays. Fenofibrate and fenofibric acid were tested by two independent laboratories measuring infection of cultured Vero cells using two different SARS-CoV-2 isolates. In both settings at drug concentrations which are clinically achievable, fenofibrate and fenofibric acid reduced viral infection by up to 70%. Together with its extensive history of clinical use and its relatively good safety profile, these studies identify fenofibrate as a potential therapeutic agent requiring urgent clinical evaluation to treat SARS-CoV-2 infection. TeaserThe approved drug fenofibrate inhibits infection by SARS-COV-2

pharmacology and toxicology↗