Biology subjects

Gruhlke, M. C. H.

Publications and source records attributed to Gruhlke, M. C. H..

3 recordsLinked to original sources

bioRxiv2021

Allicin inhibits SARS-CoV-2 replication and abrogates the antiviral host response in the Calu-3 proteome

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic is a major health burden. Volatile garlic organosulfur compounds, such as the thiol-reactive allicin (diallyl thiosulfinate) exert strong antimicrobial activity against various respiratory pathogens. Here, we investigated the antiviral activity of allicin against SARS-CoV-2 in infected Vero E6 and Calu-3 lung cells. Calu-3 cells showed greater allicin tolerance due >4-fold increased GSH levels compared to Vero E6. However, biocompatible allicin doses efficiently inhibited viral replication in both cell lines. Proteome analyses of SARS-CoV-2 infected Calu-3 cells revealed a strong induction of the antiviral interferon-stimulated gene (ISG) signature (e.g. cGAS, Mx1, IFIT, IFIH, IFI16, IFI44, 25OAS and ISG15), pathways of vesicular transport, tight junctions (KIF5A/B/C, OSBPL2, CLTC1, ARHGAP17) and ubiquitin modification (UBE2L3/5), as well as reprogramming of host metabolism, transcription and translation. Allicin abrogated the ISG host response and reverted the host cellular pathways to levels of uninfected Calu-3 cells, confirming the antiviral and immunomodulatory activity of allicin in the host proteome. Thus, biocompatible doses of allicin could be promising for protection of lung cells against SARS-CoV-2.

microbiology↗

bioRxiv2021

Allicin From Garlic Disrupts the Cytoskeleton in Plants

Allicin is a defence substance produced by garlic cells upon injury. It is a thiosulfinate showing redox-activity and a broad range of antimicrobial and biocidal activity. It is known that allicin efficiently oxidizes thiol-groups and it has been described as a redox toxin. In order to learn more about the effect of allicin on plants we used pure synthetized allicin, and investigated cytoplasmic streaming in sterile filaments of Tradescantia fluminensis, organelle movement using transgenic Arabidopsis with organelle-specifics GFP-tags, and effects on actin and tubulin in the cytoskeleton using GFP-tagged lines. Auxin distribution in roots was investigated using PIN1:GFP, PIN3:GFP, DR5:GFP and DII-VENUS Arabidopsis reporter lines. Allicin inhibited cytoplasmic streaming in T. fluminensis and organelle movement of peroxisomes and the Golgi apparatus in a concentration-dependent manner, inhibited root growth and destroyed the correct root tip distribution of auxin. We speculate that the cytoskeleton can be a primary "receptor" for allicins oxidizing properties and as a consequence cytoskeleton-dependent cellular processes are disrupted.

plant biology↗

bioRxiv2019

Plant-microbe co-evolution: allicin resistance in a Pseudomonas fluorescens strain (PfAR-1) isolated from garlic

The antibiotic defense substance allicin (diallylthiosulfinate) is produced by garlic (Allium sativum L.) after tissue damage, giving garlic its characteristic odor. Allicin is a redox-toxin that oxidizes thiols in glutathione and cellular proteins. A highly allicin-resistant Pseudomonas fluorescens strain (PfAR-1) was isolated from garlic, and genomic clones were shotgun electroporated into an allicin-susceptible P. syringae strain (Ps4612). Recipients showing allicin-resistance had all inherited a group of genes from one of three similar genomic islands (GI), that had been identified in an in silico analysis of the PfAR-1 genome. A core fragment of 8-10 congruent genes with redox-related functions, present in each GI, was shown to confer allicin-specific resistance to P. syringae, and even to an unrelated E. coli strain. Transposon mutagenesis and overexpression analyses revealed the contribution of individual candidate genes to allicin-resistance. Moreover, PfAR-1 was unusual in having 3 glutathione reductase (glr) genes, two copies in two of the GIs, but outside of the core group, and one copy in the PfAR-1 genome. Glr activity was approximately 2-fold higher in PfAR-1 than in related susceptible Pf0-1, with only a single glr gene. Moreover, an E. coli {Delta}glr mutant showed increased susceptibility to allicin, which was complemented by PfAR-1 glr1. Taken together, our data support a multi-component resistance mechanism against allicin, achieved through horizontal gene transfer during coevolution, and allowing exploitation of the garlic ecological niche. GI regions syntenic with PfAR-1 GIs are present in other plant-associated bacterial species, perhaps suggesting a wider role in adaptation to plants per se.

evolutionary biology↗