OBJECTIVES: In this preliminary study we investigated cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in blood samples from 14 recovered coronavirus disease 2019 (COVID-19) patients and compared them to those in samples from 12 uninfected/unvaccinated volunteers. METHODS: Cellular immunity was assessed by intracellular detection of IFN-γ in CD3+ T lymphocytes after stimulation with SARS-CoV-2 spike (S1), nucleocapsid (NC), or receptor-binding domain (RBD) recombinant proteins or overlapping peptide pools covering the sequence of SARS-CoV-2 spike, membrane and nucleocapsid regions. The humoral response was examined by ELISAs and/or chemiluminescence assays for the presence of serum IgG antibodies directed to SARS-CoV-2 proteins. RESULTS: We observed differences between humoral and cellular immune profiles in response to stimulation with the same proteins. Assays of IgG antibodies directed to SARS-CoV-2 NC, RBD and S1/S2 recombinant proteins were able to differentiate convalescent from uninfected/unvaccinated groups. Cellular immune responses to SARS-CoV-2 protein stimuli did not exhibit a specific response, as T cells from both individuals with no history of contact with SARS-CoV-2 and from recovered donors were able to produce IFN-γ. CONCLUSIONS: Determination of the cellular immune response to stimulation with a pool of SARS-CoV-2 peptides but not with SARS-CoV-2 proteins is able to distinguish convalescent individuals from unexposed individuals. Regarding the humoral immune response, the screening for serum IgG antibodies directed to SARS-CoV-2 proteins has been shown to be specific for the response of recovered individuals.
【저자키워드】 COVID-19, SARS-CoV-2, immune response, antigens, 【초록키워드】 coronavirus disease, Coronavirus disease 2019, coronavirus, Lymphocytes, Immunity, Cellular immune response, T cells, peptide, Immune profile, Proteins, SARS-CoV-2 peptides, severe acute respiratory syndrome Coronavirus, ELISA, Antigen, serum, T cell, IgG antibody, Receptor-binding domain, Humoral response, IgG antibodies, cellular immunity, nucleocapsid, RBD, immune responses, Patient, peptides, membrane, humoral immune response, T lymphocytes, respiratory, convalescent, chemiluminescence, volunteers, ELISAs, IFN-γ, recombinant proteins, Donor, SARS-CoV-2 spike, Stimulation, cellular, SARS-CoV-2 proteins, Contact, humoral, Recombinant protein, contact with, overlapping, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, Blood samples, pool, individual, domain, blood sample, sequence, S1/S2, T lymphocyte, cellular immune responses, SARS-CoV-2 protein, convalescent individuals, peptide pools, CD3+, serum IgG antibodies, regions, convalescent individual, shown, examined, investigated, individuals, groups, Determination, peptide pool, SARS-CoV-2 peptide, serum IgG antibody, 【제목키워드】 cellular, Recombinant protein, profile, stimulate, COVID-19 convalescent patient,