抄録
Splenectomized mice were injected intravenously with Escherichia coli endotoxin or Newcastle disease virus at different intervals. Serum and various organs were taken at different intervals and tested for virus-inhibiting factor (IF) or interferon titer. Production of endotoxin-induced IF was depressed immediately after splenectomy. This depression was recovered in six weeks. IF was then formed mainly in the lung and liver. Splenectomy did not immediately affect IF production induced with virus. In the course of time, the production of late-appearing virus-induced IF was gradually depressed, whereas the formation of early-appearing virus-induced IF was progressively enhanced. These results were interpreted as follows: (1) Endotoxin-induced IF and virus-induced early IF are formed by different mechanisms, although these IFs have similar physicochemical properties; (2) In splenectomized mice, the activity of spleen to form endotoxin-induced IF may be compensated by certain cells in various organs, whereas that for production of virus-induced late IF is not; (3) The production of virus-induced late IF depends on the spleen by a somewhat indirect way. When mice were inoculated with virus within 60 days after splenectomy, the serum IF titer was higher than those of organs. These findings suggested that the organs examined were not the major sources of virus-induced serum IF in splenectomized mice.
