In an accelerated research project to support global efforts in understanding and mitigating the COVID-19 pandemic, researchers from DTU Health Tech and Herlev University Hospital have analyzed the complete SARS-CoV-2 viral genome and identified the viral regions that are main targets for T cell mediated immune response in COVID-19 patients.
These findings are of immense importance in assessing the immune response in COVID-19 disease, to understand the mechanisms that influence disease severity and to optimize future effective vaccine designs.
T cells are important for effective viral clearance and long-term disease protection by recognizing small fragments (antigens) of viral proteins. In SARS-CoV-2 infection, early T cell activation has been reported in several studies. Thus, a detailed evaluation of T cell immunity and its clinical implication in COVID-19 disease is necessary to know the full spectrum of SARS-CoV-2-reactive T cells and their immunogenic properties.
A research team headed by Professor Sine Reker Hadrup, DTU Health Tech, now show that SARS-COV-2 infections generate a broad and strong T cell response against several viral antigens in COVID-19 disease.
Assistant Professor Sunil Kumar Saini explains: “We have found that a few viral fragments dominated the T cell activation in the majority of patients, showing immunodominance of specific viral proteins. This is based on our analysis of more than 3000 viral fragments (peptides) for T cell recognition in COVID-19 patients. Importantly, we identified that strong T cell expansion and activation is associated with severe COVID-19 disease.”
Furthermore, this study provides a detailed analysis of pre-existing T cells in healthy individuals that recognize SARS-CoV-2 antigens. These features of the T cell mediated immunity can be leveraged into therapeutic intervention and vaccine design.
These results have been published in Science Immunology.
(Photo by Jesper Scheel)