Early Diagnosis of Pathogen Infection by Cell-Based Activation Immunoassay

Cells. 2019 Aug 22;8(9):952. doi: 10.3390/cells8090952.


Diagnostic identification of pathogens is usually accomplished by isolation of the pathogen or its substances, and should correlate with the time and site of infection. Alternatively, immunoassays such as enzyme-linked immunosorbent assay (ELISA) tests for quantification of serum antibodies are expedient and are usually employed for retrospective diagnostic of a particular infective agent. Here, the potential of cell-based immunoassays for early pathogen detection was evaluated by quantification of specific, antigen-activated, low-frequency IFNγ-secreting cells in mouse spleens following infection with various pathogens. Using enzyme-linked immunospot (ELISPOT) assays, specific responses were observed within 3-6 days following infection with F. tularensis, B. anthracis, Y. pestis, or Influenza virus. Blood samples collected from F. tularensis-infected mice revealed the presence of IFNγ-producing activated cells within one week post infection. When non-human primates were infected with B. anthracis, cellular response was observed in peripheral blood samples as early as five days post infection, 3-5 days earlier than serum antibodies. Finally, the expression pattern of genes in splenocytes of F. tularensis-infected mice was inspected by a transcriptomic approach, enabling the identification of potential host targets for the future development of genetic-based cellular immunoassays. Altogether, the data demonstrate the potential of cell-based immunoassays for early pathogen detection.

Keywords: Bacillus anthracis; ELISPOT; Early detection; Francisella tularensis; Influenza virus; Yersinia pestis; animal models; infection biomarkers; lymphocyte activation; lymphocyte transcriptomics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Infections / diagnosis*
  • Early Diagnosis
  • Female
  • Immunoassay*
  • Leukocytes, Mononuclear / microbiology*
  • Leukocytes, Mononuclear / pathology
  • Leukocytes, Mononuclear / virology*
  • Macaca mulatta
  • Mice
  • Mice, Inbred C57BL
  • Virus Diseases / diagnosis*