No abstract

Interleukin 1 (IL-1) production by A/J (A) and C57BL/6J (B6) mouse peritoneal macrophages stimulated with lipopolysaccharide (LPS) was determined. Strain A macrophages produced low levels of soluble IL-1 bioactivity compared with B6 macrophages. This defect was not reversed by indomethacin, interferon-gamma, phorbol myristate acetate, or calcium ionophore A23187. In contrast, cytosolic IL-1 bioactivity was similar in LPS-stimulated A and B6 macrophages. Western blotting revealed that A macrophage supernatants contained lower levels of both 17-kd IL-1 alpha and 17-kd IL-1 beta but similar levels of tumor necrosis factor alpha compared with B6 macrophages. Cytosolic levels of 31-kd pro-IL-1 alpha and also 31-kd pro-IL-1 beta were similar in A and B6 macrophages. Oligonucleotide probing indicated that A and B6 macrophages contained similar levels of IL-1 alpha and also IL-1 beta mRNA. These findings indicate that LPS-stimulated A macrophage culture supernatants contain low levels of both IL-1 alpha and IL-1 beta compared with B6 macrophages and that these defects in IL-1 production are posttranscriptionally regulated.

No abstract

Bacteroidesgingivalis bound IgG labelled with three different enzymes even in well-buffered isotonic systems. This nonimmunological binding interferes with enzyme linked immunosorbent assay (ELISA) of salivary antibodies against B. gingivalis. B. melaninogenicus and B. intermedius showed only weak IgG binding while nine other species of oral bacteria did not bind IgG. The broad specificity of the receptor binding IgG to B. gingivalis includes not only IgG and IgA, but also proteins unrelated to immunoglobulins. Like the haemagglutinin of B. gingivalis, the receptor that binds IgG has a specificity for arginine residues with an adjacent or neighbouring aromatic amino acid residue. In contrast to the strong IgG binding of its parent, an avirulent variant B. gingivalis W5O/BEl that is deficient in trypsin-like activity, has a low level of IgG binding. Our results suggest firstly either an inactive or deactivated form of a trypsin-or papain-like enzyme, or a molecule such as the haemagglutinin, binds immunoglobulins and other proteins to the surface of B. ginghatis. Secondly, binding to arginine in proteins is an important ecological factor for B. gingivalis since it is a property shared by its IgG binding receptor, its haemagglutinin and its trypsinor papain-like enzyme. Finally, the sensitivity of ELISA to non-immunological reactions necessitates establishment of the specificity of immunoassays at levels of sensitivity comparable to those of the assays themselves.