Azido-Ceramides, a Tool to Analyse SARS-CoV-2 Replication and Inhibition-SARS-CoV-2 Is Inhibited by Ceramides

Recently, we have shown that C6-ceramides efficiently suppress viral replication by trapping the virus in lysosomes. Here, we use antiviral assays to evaluate a synthetic ceramide derivative alpha-NH2-omega-N3-C6-ceramide (AKS461) and to confirm the biological activity of C6-ceramides inhibiting SARS-CoV-2. Click-labeling with a fluorophore demonstrated that AKS461 accumulates in lysosomes. Previously, it has been shown that suppression of SARS-CoV-2 replication can be cell-type specific. Thus, AKS461 inhibited SARS-CoV-2 replication in Huh-7, Vero, and Calu-3 cells up to 2.5 orders of magnitude. The results were confirmed by CoronaFISH, indicating that AKS461 acts comparable to the unmodified C6-ceramide. Thus, AKS461 serves as a tool to study ceramide-associated cellular and viral pathways, such as SARS-CoV-2 infections, and it helped to identify lysosomes as the central organelle of C6-ceramides to inhibit viral replication.

Automated summary

Recently, the effectiveness of C6-ceramides in suppressing viral replication by trapping the virus in lysosomes has been demonstrated. In this study, a synthetic ceramide derivative called AKS461 was evaluated for its antiviral activity against SARS-CoV-2. The results showed that AKS461 accumulated in lysosomes and efficiently inhibited SARS-CoV-2 replication in different cell types. This study highlights the importance of lysosomes as the central organelle for C6-ceramides to inhibit viral replication and provides a tool for studying ceramide-associated cellular and viral pathways.