{
  "abstract": "Severe Klebsiella pneumoniae pneumonia is associated with substantial mortality and is characterized by intense systemic inflammation that coexists with a failure to control infection. The cellular changes underlying the transition from effective host defense to immune dysfunction remain incompletely defined. Here, we constructed a severity‐focused single‐cell transcriptomic atlas of 708,894 peripheral blood mononuclear cells from 100 individuals (54 healthy controls, 23 patients with mild disease, and 23 patients with severe disease), complemented by plasma protein measurements and flow cytometry. Mild disease was characterized by a relatively coordinated peripheral immune response, with preserved monocyte regulatory and tissue‐repair programs, preserved cytotoxic lymphocyte activity, and coordinated interactions between T follicular helper cells and B cells. Severe disease showed marked monocyte inflammation together with widespread disruption of adaptive immune responses. Classical monocytes expanded and showed increased expression of S100A8/A9/A12, accompanied by enhanced TLR4–MYD88 signaling and elevated plasma S100 proteins. These changes were accompanied by impaired dendritic cell antigen presentation, expansion of immunoregulatory monocyte states resembling monocytic myeloid‐derived suppressor cells, cytotoxicity‐ and exhaustion‐associated changes in CD8+ T cells and natural killer cells, hyperactivated yet poorly coordinated CD4+ T cell states, and weaker B cell receptor signaling despite plasma cell expansion. These findings delineate a severity‐associated peripheral immune state characterized by monocyte‐centered inflammatory signatures and features of altered adaptive immune coordination, and provide a basis for future mechanistic investigation of monocyte‐derived S100 alarmins and severity‐associated myeloid remodeling.",
  "abstract_shown": true,
  "affiliations": [
    "National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention Chinese Center for Disease Control and Prevention & Chinese Academy of Preventive Medicine Beijing China",
    "Department of Clinical Laboratory Shanxi Hospital of Traditional Chinese Medicine Taiyuan China",
    "NHC Key Laboratory of Pneumoconiosis, MOE Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Key Laboratory of Chronic Respiratory Diseases and Pneumoconiosis The First Hospital of Shanxi Medical University Taiyuan Shanxi China",
    "Research Center for Reverse Microbial Etiology, Workstation of Academician Shanxi Medical University Taiyuan People's Republic of China",
    "Ophthalmic Microbiology Laboratory, Shanxi Eye Hospital Shanxi Medical University Taiyuan Shanxi People's Republic of China",
    "Department of Internal Medicine, The First Clinical Medical College Shanxi Medical University Taiyuan Shanxi China",
    "School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and NHC Key Laboratory of Health Technology Assessment Fudan University Shanghai China",
    "Department of Laboratory Medicine First Hospital of Shanxi Medical University 85 Jiefang South Road Taiyuan Shanxi China",
    "Department of Respiratory and Critical Care Medicine Shanxi Hospital of Traditional Chinese Medicine Taiyuan China",
    "Department of Respiratory and Critical Care Medicine, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital Third Hospital of Shanxi Medical University Taiyuan China",
    "College of Pulmonary & Critical Care Medicine Chinese PLA General Hospital Beijing People's Republic of China",
    "Experimental Research Center & Molecular Diagnostic Center, Capital Center for Children's Health Capital Medical University, Capital Institute of Pediatrics Beijing People's Republic of China",
    "Beijing Research Center for Respiratory Infectious Diseases Beijing China"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 24,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Hongquan Chen",
      "orcid": "0000-0001-5341-9508"
    },
    {
      "affs": [
        1
      ],
      "name": "Xiaoling Wang"
    },
    {
      "affs": [
        2
      ],
      "name": "Xiang Liu"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Kui Dong"
    },
    {
      "affs": [
        0,
        5
      ],
      "name": "Yanying Feng"
    },
    {
      "affs": [
        0
      ],
      "name": "Min Yuan"
    },
    {
      "affs": [
        0
      ],
      "name": "Shiyi Wang"
    },
    {
      "affs": [
        2
      ],
      "name": "Fangfang Fan"
    },
    {
      "affs": [
        1
      ],
      "name": "Yong Tian"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Zhiming Kang"
    },
    {
      "affs": [
        6
      ],
      "name": "Xiushuai Du"
    },
    {
      "affs": [
        7
      ],
      "name": "Chaolu Hasi"
    },
    {
      "affs": [
        7
      ],
      "name": "Hong Lu"
    },
    {
      "affs": [
        8
      ],
      "name": "Wei Guan"
    },
    {
      "affs": [
        8
      ],
      "name": "Xu Chen"
    },
    {
      "affs": [
        9
      ],
      "name": "Mengyu Cheng"
    },
    {
      "affs": [
        0
      ],
      "name": "Wei Wei"
    },
    {
      "affs": [
        0,
        3
      ],
      "name": "Nan Guo"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhiguo Liu"
    },
    {
      "affs": [
        0
      ],
      "name": "Xiaotong Qiu"
    },
    {
      "affs": [
        2
      ],
      "name": "Yiwei Shi"
    },
    {
      "affs": [
        10
      ],
      "name": "Kun Xiao"
    },
    {
      "affs": [
        11,
        12
      ],
      "name": "Yi Wang",
      "orcid": "0000-0002-2031-087X"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhenjun Li"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/c81j4y3c69ws2.bib",
  "cited_by": 0,
  "doi": "10.1002/imt2.70172",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13594409/",
  "id": "c81j4y3c69ws2",
  "issns": [
    "2770-5986",
    "2770-596X"
  ],
  "landing_url": "https://doi.org/10.1002/imt2.70172",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Research Article"
    ],
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      "openalex",
      "2403|Immune cells in cancer"
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  "openalex": "W7213979281",
  "pdf_url": null,
  "pmcid": "PMC13594409",
  "pmid": "42774554",
  "published": "2026-09-21",
  "publisher": "Wiley",
  "ris": "https://research.draconitic.com/paper/c81j4y3c69ws2.ris",
  "sources": [
    {
      "first_seen": "2026-11-01T12:23:32Z",
      "native_id": "PMC13594409",
      "source": "pmc",
      "url": "https://doi.org/10.1002/imt2.70172"
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  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2403|Immune cells in cancer",
      "subfield": "immunology"
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  ],
  "title": "Monocyte inflammation and adaptive immune dysfunction in severe Klebsiella pneumoniae pneumonia",
  "title_text": "Monocyte inflammation and adaptive immune dysfunction in severe Klebsiella pneumoniae pneumonia",
  "type": "peer-reviewed",
  "updated_at": "2026-11-02T12:20:46Z",
  "url": "https://research.draconitic.com/paper/c81j4y3c69ws2",
  "venue": "iMeta",
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}