Interferon-producing capacity of germfree mice.

The general capacity of germfree mouse spleen cells to produce interferon in vitro in response to various stimuli was investigated. The interferon response of germfree mouse spleen cells in vitro, when compared with that of the conventionals, appears to be lower to some inducers. Interferon production in vitro stimulated by hemagglutinating virus of Japan (HVJ) or BHK-HVJ cells (BHK cells persistently infected with HVJ) was apparently suppressed in germfree mouse spleen cells as compared with the corresponding conventionals, whereas no difference of interferon production was observed between germfree and conventional mouse spleen cells in response to Newcastle disease virus, Escherichia coli endotoxin, poly(I:C), and phytohemagglutinin. Although monocontamination with HVJ had no enhancing effect on the interferon-producing ability of germfree mouse spleen cells in response to HVJ, conventionalization for 2 weeks greatly enhanced interferon-producing capacity.