The secretion of interleukin-12 (IL-12) following intracellular infection with virulent strain 2308 was investigated in CD-1 mice and in CD-1 cultured peritoneal macrophages. Bioactive IL-12p70 and free non-immunoactive p40 subunits (IL-12p40) were determined by enzyme-linked immunosorbent assays. In CD-1 mice, 2308 was a potent inducer of IL-12p40 (maximum levels were 5.9 and 3.4 ng/ml in sera and spleen homogenates, respectively). Secretion of IL-12p70 was also demonstrated , although at much lower levels (216.6 and 198.9 pg/ml in sera and spleen homogenates, respectively). Production of IL-12 over the first 7 days after infection was accompanied by active multiplication of in the spleens of infected mice. CD-1 cultured peritoneal macrophages secreted only IL-12p40 (878.4 pg/10 macrophages) in response to infection and no production of IL-12p70 was observed. In contrast, CD-1 peritoneal macrophages secreted detectable amounts of IL-12p70 (16.2 pg/10 macrophages) in response to purified lipopolysaccharide (S-LPS) from 2308. The macrophages also secreted significant amounts of interferon-γ (IFN-γ) (520.1 pg/10 macrophages) in response to intracellular . These results indicate that 2308 is not a potent inducer of IL-12p70 production, whereas purified S-LPS from 2308 induces the secretion of this bioactive form of IL-12 in cultured peritoneal macrophages. CD-1 peritoneal macrophages were able to secrete IFN-γ, as well as high amounts of IL-12p40, in response to intracellular infection by .


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error