Journal Article

In-vitro NET-osis induced by COVID-19 sera is associated to severe clinical course in not vaccinated patients and immune-dysregulation in breakthrough infection

Maugeri, Andrea, Botta, Ciro, Montineri, Arturo, Di Raimondo, Francesco, Barbato, Alessandro, La Ferla, Lucia, Puglisi, Fabrizio, Tibullo, Daniele, Volti, Giovanni Li, Giallongo, Cesarina, Romano, Alessandra, Parrinello, Nunziatina Laura, Iacobello, Carmelo, Palumbo, Giuseppe Alberto, Manuele, Rosy, Triolo, Anna Maria, Barchitta, Martina, Siragusa, Sergio, Agodi, Antonella

2022

Overview

Since neutrophil extracellular traps formation (NET-osis) can be assessed indirectly by treating healthy neutrophils with blood-derived fluids from patients and then measuring the NETs response, we designed a pilot study to convey high-dimensional cytometry of peripheral blood immune cells and cytokines, combined with clinical features, to understand if NET-osis assessment could be included in the immune risk profiling to early prediction of clinical patterns, disease severity, and viral clearance at 28 days in COVID-19 patients. Immune cells composition of peripheral blood, cytokines concentration and in-vitro NETosis were detected in peripheral blood of 41 consecutive COVID-19 inpatients, including 21 mild breakthrough infections compared to 20 healthy donors, matched for sex and age. Major immune dysregulation in peripheral blood in not-vaccinated COVID-19 patients compared to healthy subjects included: a significant reduction of percentage of unswitched memory B-cells and transitional B-cells; loss of naïve CD3 + CD4 + CD45RA + and CD3 + CD8 + CD45RA + cells, increase of IL-1β, IL-17A and IFN-γ. Myeloid compartment was affected as well, due to the increase of classical (CD14 ++ CD16 − ) and intermediate (CD14 ++ CD16 + ) monocytes, overexpressing the activation marker CD64, negatively associated to the absolute counts of CD8+ CD45R0+ cells, IFN-γ and IL-6, and expansion of monocytic-like myeloid derived suppressor cells. In not-vaccinated patients who achieved viral clearance by 28 days we found at hospital admission lower absolute counts of effector cells, namely CD8 + T cells, CD4 + T-cells and CD4 + CD45RO + T cells. Percentage of in-vitro NET-osis induced by patients’ sera and NET-osis density were progressively higher in moderate and severe COVID-19 patients than in mild disease and controls. The percentage of in-vitro induced NET-osis was positively associated to circulating cytokines IL-1β, IFN-γ and IL-6. In breakthrough COVID-19 infections, characterized by mild clinical course, we observed increased percentage of in-vitro NET-osis, higher CD4+ CD45RO+ and CD8+ CD45RO+ T cells healthy or mild-COVID-19 not-vaccinated patients, reduced by 24 h of treatment with ACE inhibitor ramipril. Taken together our data highlight the role of NETs in orchestrating the complex immune response to SARS-COV-2, that should be considered in a multi-target approach for COVID-19 treatment.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 631/250/127 / 631/250/2499 / 631/250/255/2514 / Blood levels / CD14 antigen / CD16 antigen / CD3 antigen / CD4 antigen / CD4-Positive T-Lymphocytes / CD45RA antigen / CD8 antigen / CD8-Positive T-Lymphocytes / Cell activation / Coronaviruses / COVID-19 / COVID-19 - drug therapy / COVID-19 Vaccines / Cytokines / Cytometry / Effector cells / Humanities and Social Sciences / Humans / IL-1β / Immune clearance / Immune response / Immunological memory / Interleukin 6 / Leukocyte Common Antigens / Leukocytes (neutrophilic) / Lymphocytes / Lymphocytes B / Lymphocytes T / Memory cells / Monocytes / multidisciplinary / Patients / Peripheral blood / Pilot Projects / SARS-CoV-2 / Science / Science (multidisciplinary) / Severe acute respiratory syndrome coronavirus 2 / Suppressor cells / γ-Interferon