Partial characterization of chicken spleen cell culture supernatants stimulated with Staphylococcus aureus

The role of accessory cells in the proliferative response of chicken spleen cells to Staphylococcus aureus Cowan I (SAC) was examined. It was found that chicken spleen cells cultured with SAC produced a soluble molecule capable of causing proliferation when culture supernatants were added to spleen cells. The molecules responsible for this activity were stable in terms of exposure to extremes of heat and pH. Gel filtration of culture supernatants revealed biological activity, over a broad range of molecular weights, as measured by spleen cell proliferation. Similar findings were obtained when SAC was sonicated and evaluated following gel filtration. Exposure of culture supernatants to trypsin abrogated biological activity. The pivotal role of adherent cells in the generation of biologically active molecules is suggested by the ability of peritoneal exudate cells incubated with SAC to produce biologically active supernatants. In addition, the proliferative response of spleen cells to SAC was sensitive to chloroquine.