Covid-19, a research by the Istituto Superiore di Sanità confirms that type I interferon can block the progression of the disease
A new weapon could arrive from Italy in the fight against Covid-19. Type I interferon (IFN), released by plasmacytoid dendritic cells (pDc) at the beginning of coronavirus infection, appears to elicit an immune response in the body that blocks the progression of the disease. The discovery comes from the joint work of a team of researchers (University of San Raffaele in Milan, Polyclinic of Tor Vergata, University of Padua, Metabolic Fitness Association) coordinated by the Istituto Superiore di Sanita ‘(ISS). The study published in Plos Pathogens analyzes precisely the mechanisms of innate immune responses in the pathogenesis of Covid-19.
“We studied the early interaction between SARS-CoV-2 and the cells of the immune system in an experimental in vitro model based on human peripheral blood cells – explains Eliana Coccia of the ISS, head of the investigation – and we saw that even in the absence of productive viral replication, the virus promotes an important release of type I and III Ifn and inflammatory cytokines and chemokines (i.e. molecules that act as mediators of natural immunity and inflammatory response), known to contribute to the cytokine storm observed in Covid-19 “.
Covid-19 and interferon: “It could lead to new therapies for the initial phase of the disease”
“It was interesting to observe that type I Ifn, released by pDCs, is able to stimulate the antiviral response in infected lung epithelial cells,” adds Coccia. From these in vitro findings, researchers characterized the pDC phenotype and the balance between antiviral cytokines and pro-inflammatory cytokines of Covid-19 patients based on disease severity. They therefore observed that the expression of the PD-L1 marker on the surface of the pDCs, as well as their frequency in peripheral blood, differs if the patient is asymptomatic or if he has severe symptoms. “Asymptomatic subjects – continues Nicola Clementi of the Vita-Salute San Raffaele University – have pDCs in their circulation that release type I IFNs and this data is perfectly combined with very high serum levels of these factors and with the induction of genes anti-virals stimulated by the IFN itself. In contrast, hospitalized patients with severe Covid-19 show a very low frequency of circulating pDCs with an inflammatory phenotype and high levels of pro-inflammatory chemokines and cytokines in serum “.
“Our study – conclude the authors – confirms the crucial and protective role in Covid-19 disease of the pDC / Ifn type I axis, whose greater understanding can contribute to the development of new pharmacological strategies and / or therapies aimed at to enhance the response of pDCs from the early stages of Sars-CoV-2 infection “. The results obtained in this study were achieved thanks to the close collaboration between researchers and clinicians as specified below: Department of Infectious Diseases, Istituto Superiore di Sanita ‘(Rome) Eliana M Coccia, Marilena P. Etna, Stefano Fiore, Daniela Ricci, Fabiana Rizzo, Martina Severa, Paola Stefanelli; Infectious Diseases Clinic, Tor Vergata Polyclinic (Rome) Massimo Andreoni, Marco Iannetta, Alessandra Lodi; Department of Molecular Medicine, University of Padua (Padua) Luisa Barzon, Alessandro Sinigaglia; Microbiology and Virology Laboratory, San Raffaele Life-Health University (Milan); Massimo Clementi, Nicola Clementi, Elena Criscuolo, Roberta Diotti, Nicasio Mancini; Metabolic Fitness Association (Monterotondo) Stefano Balducci.