PASTEURELLA-HAEMOLYTICA A1 PURIFIED CAPSULAR POLYSACCHARIDE DOES NOT STIMULATE INTERLEUKIN-1 AND TUMOR-NECROSIS-FACTOR RELEASE BY BOVINE MONOCYTES AND ALVEOLAR MACROPHAGES

Purified capsular polysaccharide (CPS) stimulated significant release of interleukin-1 (IL-1) activity from bovine blood monocytes but not alveolar macrophages in vitro. The ability of CPS to induce IL-1 release was resistant to boiling and inhibited by the addition of polymyxin-beta. Thus, it is likely that the IL-1 release stimulated by CPS resulted from the small amount of contaminating lipopolysaccharide (LPS) that was present (an estimated 5 pg LPS per-mu-g CPS) rather than to a direct effect of CPS. Tumor necrosis factor activity was not detected in the culture supernatants of bovine monocytes incubated with purified CPS for 1-18 h in vitro.