The SARS-CoV-2 nucleoprotein induces innate memory in human monocytes

The interaction of SARS-CoV-2 with the human immune system is at the basis of the positive or negative outcome of the infection. Monocytes and macrophages, which are major innate im-mune/inflammatory effector cells, are not directly infected by SARS-CoV-2, however they can react to the virus and mount a strong reaction. How this first interaction and reaction may bias innate reactivity to re-challenge, a phenomenon known as innate memory, is currently unex-plored and may be part of the long-term sequelae of COVID-19. Here, we have tested the capac-ity of SARS-CoV-2 and some of its proteins to induce innate memory in human monocytes in vitro. Results show that, while the Spike protein subunits S1 and S2 and the entire heat-inactivated virus have no substantial effect, monocytes pre-exposed to the nucleocapsid N protein react to subsequent viral or bacterial challenges with an increased production of an-ti-inflammatory IL-1Ra, a response profile suggesting a milder response to new infections.

URBAN LOPEZ Patricia;  ITALIANI Paola;  BORASCHI Diana;  GIORIA Sabrina; 

2022-07-20

FRONTIERS MEDIA SA

JRC126517

1664-3224 (online),   

https://www.frontiersin.org/articles/10.3389/fimmu.2022.963627,    https://publications.jrc.ec.europa.eu/repository/handle/JRC126517,   

10.3389/fimmu.2022.963627 (online),