Reduced interleukin-18 secretion in Brucella abortus 2308-infected murine peritoneal macrophages and in spleen cells obtained from B. abortus 2308-infected mice.
Th1 immune responses in which gamma interferon (IFN-gamma) production predominates are associated with protective immunity against intracellular bacteria. Following infection, interleukin-18 (IL-18) may contribute, in association with IL-12, to optimal IFN-gamma production. In this study, the secretion of IL-18 following intracellular infection with virulent Brucella abortus 2308 in CD-1 cultured peritoneal macrophages and splenocyte cultures was investigated. The production of IL-18 was reduced in both CD-1 mouse peritoneal macrophages infected with B. abortus 2308 and splenocyte cultures obtained from B. abortus 2308-infected mice at 3, 6 and 10 days post-infection (p.i.). In contrast, splenocyte cultures obtained from B. abortus 2308-infected mice at 3 days p.i. secreted significant amounts of IFN-gamma. Stimulation of these cells with recombinant IL-18 (rIL-18) and/or rIL-12 did not significantly increase IFN-gamma secretion at the splenocyte level. These data suggest that once the infection has been established, B. abortus 2308 selectively limits IL-18 secretion without affecting endogenous IFN-gamma production.
Fernández-Lago
Luis
L
Departamento de Microbiología y Genética, Edificio Departamental, Universidad de Salamanca, Plaza Doctores de la Reina s/n, 37007 Salamanca, Spain 2Departamento de Microbiología, Facultad de Medicina, Universidad de Valladolid, Valladolid, Spain.
Orduña
Antonio
A
Departamento de Microbiología y Genética, Edificio Departamental, Universidad de Salamanca, Plaza Doctores de la Reina s/n, 37007 Salamanca, Spain 2Departamento de Microbiología, Facultad de Medicina, Universidad de Valladolid, Valladolid, Spain.
Vizcaíno
Nieves
N
Departamento de Microbiología y Genética, Edificio Departamental, Universidad de Salamanca, Plaza Doctores de la Reina s/n, 37007 Salamanca, Spain 2Departamento de Microbiología, Facultad de Medicina, Universidad de Valladolid, Valladolid, Spain.
D000818:Animals; D021461:Animals, Outbred Strains; D002003:Brucella abortus; D002006:Brucellosis / Q000276:immunology*; D002478:Cells, Cultured; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007371:Interferon-gamma / Q000096:biosynthesis; D018664:Interleukin-12 / Q000494:pharmacology; D020382:Interleukin-18 / Q000096:biosynthesis* / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D013154:Spleen / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology; D013997:Time Factors
D020382:Interleukin-18; D018664:Interleukin-12; D007371:Interferon-gamma