{
  "abstract": "Although SARS-CoV-2 immunity has been widely investigated, the relationship between antibody levels and cellular immune responses following different routes of exposure to SARS-CoV-2 remains not fully revealed. In this study, cellular immunity was assessed using a newly developed whole-blood interferon-gamma release assay (nano-IGRA) based on gold nanoparticle (AuNP)-conjugated SARS-CoV-2 antigens. AuNP-conjugated and soluble antigens were compared regarding interferon gamma (IFN-γ) responses and intra- and interassay reproducibility in 112 individuals with immunity acquired through infection, vaccination, or both. Humoral immunity was evaluated by enzyme-linked immunosorbent assay (ELISA). Overall, 88% of participants were seropositive. AuNP-conjugated Spike (S) and Nucleocapsid (N) SARS-CoV-2 antigens induced significantly higher IFN-γ responses than soluble antigens in all exposure groups (p < 0.001). AuNP conjugation reduced intraassay variability by 62.4% and 61.4% for S and N, respectively, and interassay variability by 71.7% and 68.3%, respectively. Antibody levels correlated significantly with IFN-γ responses to S (ρ = 0.358, p < 0.001) and N (ρ = 0.309, p < 0.001). An interesting finding is that cellular responses were also detected in some seronegative individuals. Nano-IGRA, based on a novel AuNP-based approach, provides antigen-specific cellular immune assessment, combining enhanced IFN-γ responses with improved reproducibility. Further studies should establish diagnostic cut-offs, sensitivity, specificity, and clinical performance.",
  "abstract_shown": true,
  "affiliations": [
    "Institute for the Application of Nuclear Energy INEP, University of Belgrade, Banatska 31b, 11080 Belgrade, Serbia.",
    "Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Aleksandra Todorović",
      "orcid": "0000-0003-2225-8988"
    },
    {
      "affs": [
        0
      ],
      "name": "Danica Ćujić",
      "orcid": "0000-0002-6145-3850"
    },
    {
      "affs": [
        1
      ],
      "name": "Zorica Knežević Jugović",
      "orcid": "0000-0003-3009-1698"
    },
    {
      "affs": [
        1
      ],
      "name": "Petar Uskoković",
      "orcid": "0000-0001-9543-1732"
    },
    {
      "affs": [
        1
      ],
      "name": "Dušica Stojanović",
      "orcid": "0000-0001-6308-7586"
    },
    {
      "affs": [
        0
      ],
      "name": "Marija Gnjatović",
      "orcid": "0000-0001-8233-1636"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1tr8szq0beecd.bib",
  "cited_by": 0,
  "doi": "10.3390/ijms27198664",
  "fulltext_url": "https://europepmc.org/articles/PMC13664868",
  "id": "1tr8szq0beecd",
  "issns": [
    "1422-0067"
  ],
  "landing_url": "https://europepmc.org/article/MED/42883910",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2725|SARS-CoV-2 and COVID-19 Research"
    ]
  ],
  "openalex": "W7214582219",
  "pdf_url": "https://europepmc.org/articles/PMC13664868?pdf=render",
  "pmcid": "PMC13664868",
  "pmid": "42883910",
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1tr8szq0beecd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:16Z",
      "native_id": "MED:42883910",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42883910"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2725|SARS-CoV-2 and COVID-19 Research",
      "subfield": "infectious-disease"
    }
  ],
  "title": "Integrated Assessment of Humoral and Cellular SARS-CoV-2 Immunity Using ELISA and a Gold Nanoparticle-Based IGRA.",
  "title_text": "Integrated Assessment of Humoral and Cellular SARS-CoV-2 Immunity Using ELISA and a Gold Nanoparticle-Based IGRA.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:16Z",
  "url": "https://research.draconitic.com/paper/1tr8szq0beecd",
  "venue": "International journal of molecular sciences",
  "versions": []
}