The consequences of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can range from asymptomatic to fatal disease. Variations in epithelial susceptibility to SARS-CoV-2... Show moreThe consequences of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can range from asymptomatic to fatal disease. Variations in epithelial susceptibility to SARS-CoV-2 infection depend on the anatomical location from the proximal to distal respiratory tract. However, the cellular biology underlying these variations is not completely understood. Thus, air-liquid interface cultures of well-differentiated primary human tracheal and bronchial epithelial cells were employed to study the impact of epithelial cellular composition and differentiation on SARS-CoV-2 infection by transcriptional (RNA sequencing) and immunofluorescent analyses. Changes of cellular composition were investigated by varying time of differentiation or by using specific compounds. We found that SARS-CoV-2 primarily infected not only ciliated cells but also goblet cells and transient secretory cells. Viral replication was impacted by differences in cellular composition, which depended on culturing time and anatomical origin. A higher percentage of ciliated cells correlated with a higher viral load. However, DAPT treatment, which increased the number of ciliated cells and reduced goblet cells, decreased viral load, indicating the contribution of goblet cells to infection. Cell entry factors, especially cathepsin L and transmembrane protease serine 2, were also affected by differentiation time. In conclusion, our study demonstrates that viral replication is affected by changes in cellular composition, especially in cells related to the mucociliary system. This could explain in part the variable susceptibility to SARS-CoV-2 infection between individuals and between anatomical locations in the respiratory tract. (c) 2023 The Author(s). Published by S. Karger AG, Basel Show less
Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) specific CD4(+ )and CD8(+) T cells in SARS- CoV- 2-unexposed donors has been explained by the presence of T cells primed... Show moreDetection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) specific CD4(+ )and CD8(+) T cells in SARS- CoV- 2-unexposed donors has been explained by the presence of T cells primed by other coronaviruses. However, based on the relatively high frequency and prevalence of cross-reactive T cells, we hypothesized cytomegalovirus (CMV) may induce these cross-reactive T cells. Stimulation of pre-pandemic cryo-preserved peripheral blood mononuclear cells (PBMCs) with SARS- CoV- 2 peptides revealed that frequencies of SARS- CoV- 2-specific T cells were higher in CMVseropositive donors. Characterization of these T cells demonstrated that membrane-specific CD4(+ )and spike-specific CD8(+) T cells originate from cross-reactive CMVspecific T cells. Spike-specific CD8(+ )T cells recognize SARS- CoV- 2 spike peptide FVSNGTHWF (FVS) and dissimilar CMV pp65 peptide IPSINVHHY (IPS) presented by HLA- B*35:01. These dual IPS/FVS-reactive CD8(+) T cells were found in multiple donors as well as severe COVID- 19 patients and shared a common T cell receptor (TCR), illustrating that IPS/FVS- cross-reactivity is caused by a public TCR. In conclusion, CMVspecific T cells cross react with SARS-CoV- 2, despite low sequence homology between the two viruses, and may contribute to the pre-existing immunity against SARS-CoV- 2. Show less
Salgado-Benvindo, C.; Thaler, M.; Tas, A.; Ogando, N.S.; Bredenbeek, P.J.; Ninaber, D.K.; ... ; Hemert, M.J. van 2020
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic that originated in Wuhan, China, in December 2019 has impacted public health, society, the global economy, and the daily... Show moreThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic that originated in Wuhan, China, in December 2019 has impacted public health, society, the global economy, and the daily lives of billions of people in an unprecedented manner. There are currently no specific registered antiviral drugs to treat or prevent SARS-CoV-2 infections. Therefore, drug repurposing would be the fastest route to provide at least a temporary solution while better, more specific drugs are being developed. Here, we demonstrate that the antiparasitic drug suramin inhibits SARS-CoV-2 replication, protecting Vero E6 cells with a 50% effective concentration (EC50) of similar to 20 mu M, which is well below the maximum attainable level in human serum. Suramin also decreased the viral load by 2 to 3 logs when Vero E6 cells or cells of a human lung epithelial cell line (Calu-3 2B4 [referred to here as "Calu-3"]) were treated. Time-of-addition and plaque reduction assays performed on Vero E6 cells showed that suramin acts on early steps of the replication cycle, possibly preventing binding or entry of the virus. In a primary human airway epithelial cell culture model, suramin also inhibited the progression of infection. The results of our preclinical study warrant further investigation and suggest that it is worth evaluating whether suramin provides any benefit for COVID-19 patients, which obviously requires safety studies and well-designed, properly controlled randomized clinical trials. Show less
