COVID-19: S-Peptide RBD <sub>484–508</sub> Induces IFN-γ T-Cell Response in Naïve-to-Infection and Unvaccinated Subjects with Close Contact with SARS-CoV-2-Positive Patients
Michela Murdocca,
Gennaro Citro,
Eleonora Centanini,
Rosalinda Giannini,
Andrea Latini,
Federica Centofanti,
Eva Piano Mortari,
Dario Cocciadiferro,
Antonio Novelli,
Sergio Bernardini,
Giuseppe Novelli,
Federica Sangiuolo
Affiliations
Michela Murdocca
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Gennaro Citro
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Eleonora Centanini
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Rosalinda Giannini
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Andrea Latini
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Federica Centofanti
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Eva Piano Mortari
B Cell Unit, Immunology Research Area, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy
Dario Cocciadiferro
Medical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy
Antonio Novelli
Medical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy
Sergio Bernardini
Department of Experimental Medicine, University of Tor Vergata, 00133 Rome, Italy
Giuseppe Novelli
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Federica Sangiuolo
Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
Despite the availability on the market of different anti-SARS-CoV-2 vaccines, there are still unanswered questions on whether they can stimulate long-lasting protection. A deep understanding of adaptive immune response to SARS-CoV-2 is important for optimizing both vaccine development and pandemic control measures. Among cytokines secreted by lymphocytes in response to viral infection, IFN-γ plays a pivotal role both in innate and adaptive immunity. In this study, we report on 28 naïve-to-SARS-Cov-2-infection and unvaccinated subjects, having reported a close and prolonged contact with COVID-19-positive patients. Samples were tested for defective genetic variants in interferon pathway genes by whole exome sequencing and anti-IFN autoantibodies production was investigated. Subject T-cells were cultured and infected with pseudotype particles bearing the S proteins and in parallel stimulated with two S-peptides designed on the RBD region of the spike protein. Our results showed that one of these peptides, RBD 484–508, induces a significant increase in IFN-γ gene expression and protein production in T-cells, comparable to those obtained in cells infected by SARS-CoV-2 pseudovirus. This work deepens our understanding of immune response and highlights the selected peptide as a reasonable approach to induce broad, potent, and variant concern-independent T-cell responses.
