Endogenous IL-15 might be responsible for early protection by natural killer cells against infection with an avirulent strain of Salmonella choleraesuis in mice.
Interleukin (IL)-15 is a novel cytokine with growth factor activity for T cells, B cells, and natural killer cells (NK cells). We investigated the role of IL-15 in the host defense against infection with avirulent Salmonella choleraesuis strain 31N-1 cured of 50-kb virulent plasmid. IL-15 was abundantly expressed at transcription and protein levels in macrophages infected with S. choleraesuis 31N-1. The number of NK cells in the infected sites was increased during the course of infection coincident with IL-15 production. Anti-IL-15 mAb administration inhibited the emergence of NK cells and interferon-gamma (IFN-gamma) production in serum after infection with S. choleraesuis 31N-1 and concurrently impaired the clearance of the bacteria. These results suggested that IL-15 might be responsible for protection against avirulent S. choleraesuis infection at early stage of infection through activation of NK cells in the infected sites.
Hirose
K
K
Laboratory of Host Defense and Germfree Life, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Japan.
Nishimura
H
H
Matsuguchi
T
T
Yoshikai
Y
Y
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002478:Cells, Cultured; D005260:Female; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis; D019409:Interleukin-15 / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008099:Liver / Q000276:immunology; D018655:Lymphocyte Count; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010529:Peritoneal Cavity / Q000473:pathology; D010957:Plasmids; D016692:Receptors, Antigen, T-Cell, gamma-delta; D012475:Salmonella / Q000276:immunology* / Q000472:pathogenicity; D012481:Salmonella Infections, Animal / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014774:Virulence
D000911:Antibodies, Monoclonal; D019409:Interleukin-15; D016692:Receptors, Antigen, T-Cell, gamma-delta; D007371:Interferon-gamma