The SARS-CoV-2 Spike S1 Protein Induces Global Proteomic Changes in ATII-Like Rat L2 Cells that are Attenuated by Hyaluronan

The COVID-19 pandemic continues to impose a major impact on global health and economy since its identification in early 2020, causing significant morbidity and mortality worldwide. Caused by the SARS-CoV-2 virus, along with a growing number of variants that have been characterized to date, COVID-19 has led to 571,198,904 confirmed cases, and 6,387,863 deaths worldwide (as of July 15th, 2022). Despite tremendous advances in our understanding of COVID19 pathogenesis, the precise mechanism by which SARS-CoV2 causes epithelial injury is incompletely understood. In this current study, robust application of global-discovery proteomics applications combined with systems biology analysis identified highly significant induced changes by the Spike S1 protein of SARS-CoV-2 in an ATII-like Rat L2 cells that include three significant network hubs: E2F1, CREB1/ RelA, and ROCK2/ RhoA. Separately, we found that pre-treatment with High Molecular Weight Hyaluronan (HMW-HA), greatly attenuated the S1 effects. Immuno-targeted studies carried out on E2F1 and Rock2/ RhoA induction and kinase-mediated activation, in addition to cell cycle measurements, validated these observations. Taken as a whole, our discovery proteomics and systems analysis workflow, combined with standard immuno-targeted and cell cycle measurements revealed profound and novel biological changes that contribute to our current understanding of both Spike S1 and Hyaluronan biology. This data shows that the Spike S1 protein may contribute to epithelial injury induced by SARS-CoV-2. In addition, our work supports the potential benefit of HMW-HA in ameliorating SARS CoV2 induced cell injury.

Local SARS-CoV-2 peptide-specific Immune Responses in Convalescent and Uninfected Human Lung Tissue Models

Multi-specific and long-lasting T cell immunity have been recognized as indicators for long term protection against pathogens including the novel coronavirus SARS-CoV-2, the causative agent of the COVID-19 pandemic. Functional significance of peripheral memory T cells in individuals recovering from COVID-19 (COVID-19+) are beginning to be appreciated; but little is known about lung resident memory T cells (lung TRM) in SARS-CoV-2 infection. Here, we utilize a perfused three dimensional (3D) human lung tissue model and identify pre-existing local T cell immunity against SARS-CoV-2 proteins in lung tissues. We report ex vivo maintenance of functional multi-specific IFN-{gamma} secreting lung TRM in COVID-19+ and their induction in lung tissues of vaccinated COVID-19+. Importantly, we identify SARS-CoV-2 peptide-responding B cells and IgA+ plasma cells in lung tissues of COVID-19+ in ex vivo 3D-tissue models. Our study highlights the importance of balanced and local anti-viral immune response in the lung with persistent induction of TRM and IgA+ plasma cells for future protection against SARS-CoV-2 infection. Further, our data suggest that inclusion of multiple viral antigens in vaccine approaches may broaden the functional profile of memory T cells to combat the severity of coronavirus infection.