{
  "abstract": "Introduction: T cell mediated immunity (T-CMI) is an important component of effective host immunity against intracellular pathogens such as Salmonella enterica serovar Typhi ( S. Typhi; ST). Baseline T-CMI responsiveness to S. Typhi has been previously described in healthy individuals, likely reflecting cross-reactive responsiveness to other Enterobacteriaceae within the gut microbiota. Interestingly, T cell baseline responsiveness has been associated with protection or susceptibility in a human challenge model following exposure to wild-type (wt) ST. To better understand the contribution of this baseline responsiveness to immunity against ST infection, an in-depth characterization of T cell immunity is needed.\n\nMethods: Here, peripheral blood mononuclear cells from eighteen healthy volunteers with no history of typhoid fever vaccination or infection were co-cultured with autologous B-lymphoblastoid cell lines (B-LCL) previously infected with wt ST as antigen presenting cells. Non-infected B-LCL (NI) were used as controls. After 18 h or 40 h of stimulation, cells were stained with a 52-parameter mass cytometry antibody panel and analyzed using manual gating, dimensionality reduction and unsupervised clustering approaches. We studied conventional CD4 ⁺ and CD8 ⁺ T memory cells, including T effector memory (T EM ), T EM re-expressing CD45RA (T EMRA ), and T central memory (T CM ), CD4 ⁺ and CD8 ⁺ T stem cell memory (T SCM ), CD4 ⁺ circulating T follicular helper (cT FH ), CD4 ⁺ T regulatory (T reg ), and CD8 ⁺ T regulatory precursors (T rp ), as well as non-conventional CD8 ⁺ mucosal associated invariant T (MAIT), T gamma delta (Tγδ), and Natural-Killer T (NKT) cells.\n\nResults: All studied cell subsets showed significant (p<0.01) baseline responsiveness to ST-infected target cells when compared to NI target cells. Most functional responses were observed in activation, homing, and cytotoxicity markers across all conventional and non-conventional T cell subsets, defining in great depth the characteristics of baseline T-CMI to S. Typhi.\n\nDiscussion: This high-dimensional approach showed a complex interaction between distinct cell subsets with multifunctional properties and extended previous insights into the baseline T-CMI to S. Typhi. This will help guide future investigations of immunity in healthy individuals following infection or vaccination.",
  "abstract_shown": true,
  "affiliations": [
    "Center for Vaccine Development and Global Health, University of Maryland School of Medicine , , ,"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Laura E. Carreto-Binaghi"
    },
    {
      "affs": [
        0
      ],
      "name": "Jayaum S. Booth"
    },
    {
      "affs": [
        0
      ],
      "name": "Rezwanul Wahid"
    },
    {
      "affs": [
        0
      ],
      "name": "Rosangela Salerno-Goncalves"
    },
    {
      "affs": [
        0
      ],
      "name": "Franklin R. Toapanta"
    },
    {
      "affs": [
        0
      ],
      "name": "Marcelo B. Sztein"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0ftmdwa8sfbp6.bib",
  "cited_by": 0,
  "doi": "10.3389/fimmu.2026.1940148",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669112/?tool=EBI",
  "id": "0ftmdwa8sfbp6",
  "issns": [
    "1664-3224"
  ],
  "landing_url": "https://europepmc.org/article/PMC/PMC13669112",
  "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",
      "2403|T-cell and B-cell Immunology"
    ]
  ],
  "openalex": "W7215052514",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669112/pdf/?tool=EBI",
  "pmcid": "PMC13669112",
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/0ftmdwa8sfbp6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:25Z",
      "native_id": "PMC:PMC13669112",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13669112"
    },
    {
      "first_seen": "2026-10-30T12:19:15Z",
      "native_id": "10.3389/fimmu.2026.1940148",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1940148/full"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2403|T-cell and B-cell Immunology",
      "subfield": "immunology"
    }
  ],
  "title": "Broad systemic T cell immunity to Salmonella enterica serovar Typhi in U.S. healthy adults",
  "title_text": "Broad systemic T cell immunity to Salmonella enterica serovar Typhi in U.S. healthy adults",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:15Z",
  "url": "https://research.draconitic.com/paper/0ftmdwa8sfbp6",
  "venue": "Frontiers in immunology",
  "versions": []
}