Filenews 12 May 2021
Immune response to coronavirus is critical for disease control because there is concern that weakened immunity due to the significant degree of reduction in antibodies coming from spike protein (spike protein, SP) can lead to re-infection by the virus.
However, Immunity due to T-cells plays an important role in controlling SARS-CoV-2 infection but has not been studied enough. In the journal Nature Immunology, a recent study explored the role of T-cells. The main data of the publication are summarized by the Professors of the National and Kapodistrian University of Athens, Antonis Kolokouris (Department of Pharmacy), Evangelos Terpos (Professor of Medical School) and Thanos Dimopoulos (Rector of ekpa) as well as the graduate student of Pharmaceutical Chemistry Vangelis Knife.
The study included 100 volunteers in which, 6 months after SARS-CoV-2 infection, the phenotype and number of specialized T-cells were determined. Levels of antibodies against spike protein had decreased significantly. T-cell responses to cytokines (ELISpot method) were studied and emphasis was placed on CD4+ T-cells which cause the strong response of cytokine interleukin (IL)-2 associated with the degree of response. T-cell responses were 50% higher in donors previously infected with SARS-CoV-2 and had symptoms, indicating T-cell response.
The correlation of T-cell response with the levels of corresponding antibodies was also studied. Specifically, the level of T-cells that respond to spike protein and the level of T-cells that respond to nucleoproteins/membrane proteins of the virus were correlated. T-cell levels specific to the nucleoprotein virus have always been found to be high, which together with antibodies that are specific to nucleoprotein are an immune response for this virus protein. However, such high levels of T-cells combined with the antibodies produced by spike protein were not observed.
In conclusion, these data show that the majority of infected individuals develop specific CD4+ T-cells compared to SARS-CoV-2, the production of which is not derived from a response to spike protein. This specific immunity from T-cells is maintained at least 6 months after infection and needs to be studied afterwards because it gives scientists the idea of developing vaccines that cause constant immunity.
