This study investigates the effect of intraperitoneal injection of L. bulgaricus and S. thermophilus on interferon production by Swiss mice. The serum from mice given 5 x 10(7) L. bulgaricus in 0.5 ml saline showed a maximal production of 300 U/ml of alpha/beta interferon activity six hours after injection. Cellular integrity appears to be necessary for stimulation; heat-treated bacteria had little effect, while irradiated-bacteria had a greater effect. TNF was also produced, the sera of mice with high IFN also contained 300 U/ml TNF. Streptococcus thermophilus produced no detectable increase in serum IFN, but the 2'-5' A synthetase activity of peritoneal cells was elevated suggesting that small amounts of interferon were produced. Injection of Streptococcus thermophilus plus Lactobacillus bulgaricus did not change the serum interferon response to L. bulgaricus. These observations suggest that non-pathogenic bacteria such as those used in food processing, can stimulate IFN production in mice. There is some evidence that the bacterial cell walls might be responsible for at least part of this effect.

2',5'-Oligoadenylate Synthetase↗

PubMedDate not supplied

Affinity chromatographic analysis of murine interferons induced by viruses and by T and B cell stimulants.

Murine interferons induced by viruses and by non-viral substances such as lectins, tilorone, lipopolysaccharide and Brucella have been analysed by affinity chromatography on a column of Sepharose coupled to antiviral interferon antibodies. The results reported here suggest that virus and B-cell stimulants induced interferons which are antigenically related and that T cell-dependent mitogens induce and "interferon like" molecule which appears to be antigenically and physiocochemically different.

Animals↗

PubMedDate not supplied

Inhibitory effect of interferon on DNA and RNA synthesis in murine spleen cells stimulated by lectins.

Spleen cells from mice inoculated with partially purified preparations of interferon (Sp. Act. 1 X 10(7) i.u./mg protein, 0.2 ml i. v./mouse) were stimulated in vitro with phytohemagglutinin, concanavalin A or lipopolysaccharide. After 2 days of stimulation, the incorporation of 3H-thymidine into TCA-insoluble radioactivity was inhibited 50-90% when compared with cells from animals inoculated with mock interferon. Maximal inhibition, with optimal doses of lectins was obtained when interferon was;inoculated 18 hours before. This effect of interferon on DNA synthesis was preceeded by inhibition of the incorporation of 3H-uridine into TCA-insoluble material. When cells were pretreated in vitro with interferon for 24 hours and subsequently stimulated with PHA, RNA synthesis was inhibited by 30-40%, whatever was the dose of the mitogen. The synthesis of 4S tRNA, 18S and 28S ribosomal RNAs were inhibited to the same degree by interferon. The incorporation of methyl groups into cytoplasmic sRNA was unaltered.

Animals↗