Enrichment of coronavirus-induced interferon-producing blood leukocytes increases the interferon yield per cell: a study with pig leukocytes.
Porcine peripheral blood mononuclear cells, which secrete IFN alpha in response to a coronavirus, transmissible gastroenteritis virus, were detected by a filter immunoplaque assay (ELISPOT). IFN alpha-producing cells (IPC), which are present at a low frequency in the blood, could be enriched up to 100-fold by sequential depletion of plastic-adherent cells and cell fractionation on metrizamide density gradients. IPC were present in the non-adherent low-density cell subpopulation. Cell selection experiments using antibody (Ab)-coated immunomagnetic beads revealed that porcine IPC could be positively selected by anti-CD4 or -SLA-class-II Ab, but not by anti-CD2 or -CD8 Ab. The estimated IFN yield per IPC was found to increase when IPC were assayed at higher concentrations. These data suggest that IPC represent a unique and distinct cell population in the blood, which could secrete higher amounts of IFN following its accumulation at a site of viral infection.
Laboratoire de Virologie et Immunologie moléculaires, INRA, Jouy-en-Josas, France.
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Nowacki
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Charley
D000818:Animals; D000911:Antibodies, Monoclonal; D015704:CD4 Antigens / Q000276:immunology; D002452:Cell Count; D002458:Cell Fractionation; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D004797:Enzyme-Linked Immunosorbent Assay; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D016898:Interferon-alpha / Q000096:biosynthesis*; D007962:Leukocytes / Q000378:metabolism* / Q000382:microbiology; D008793:Metrizamide; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000502:physiology*
D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D000949:Histocompatibility Antigens Class II; D016898:Interferon-alpha; D008793:Metrizamide