Team led by a Tyrolean researcher in the USA reports findings in the journal “Science” – could at least partially explain very different disease courses
According to a study by a team led by Tyrolean researcher Daniela Weiskopf, who works in the United States, the body’s own immune defense cells could be partially prepared for SARS-CoV-2 by previous infections with other coronaviruses. In the journal Science, the researchers see a possible explanation for the large differences in the course of Covid 19 disease.
A group around the scientist working at the La Jolla Institute for Immunology (LJI) in Southern California already dealt with the role of T cells in connection with the new corona virus in a study presented in the journal “Science Immunology” in July. This is a group of white blood cells whose job it is to identify new threats and to advance the acquired immune response. In contrast to B lymphocytes, T cells do not produce specific antibodies that position themselves against the virus, but must recognize their target structures directly on the surface of the pathogen.
Not only did the scientists find that they succeeded surprisingly well in the case of the new SARS-CoV-2 virus, but that special T cells could even surprisingly detect large parts of the new pathogen. In the first examination, Weiskopf and colleagues also confronted older blood samples from 2015 to 2018 with the new virus. They noticed that T cells in almost half of the samples taken long before the Covid 19 pandemic showed a reaction to virus parts. Here one could be dealing with cross-immunity “that is caused by normal common cold viruses,” Weiskopf told APA at the time.
The scientist has now investigated this assumption with the first author of the new study, Jose Mateus: Again, they confronted blood samples taken before 2019 with over 100 parts of the new corona virus. It was shown that a whole range of T cells reacted both to SARS-CoV-2 and to a range of human coronaviruses that trigger normal colds. The strongest immune responses were triggered by the characteristic spike protein of the SARS-CoV-2 virus, which the pathogen uses to penetrate human cells.
In contrast to the neutralizing antibodies produced by the B lymphocytes, which the immune system can only position very specifically against individual human cold viruses and not against the new coronavirus, the T cells can apparently also use their information acquired through previous diseases in combat against the new pathogen. According to Weiskopf and colleagues, this could explain at least to some extent why Covid 19 disease takes such different courses.