Jerome P. Schmidt

Effect of Interferon Inducers and Interferon on Bacterial Infections

The effect of interferon inducers and exogenous L-cell interferon on the infection of mice by Pasteurella tularensis or Diplococcus pneumoniae was investigated. The results indicate that the degree of protection is dependent on the type of inducer used. A variety of defense mechanisms with limited nonspecific activity appear to be involved.

Tilorone Hydrochloride: Lack of Correlation Between Interferon Induction and Viral Protection

The protection of mice against MM virus infection and the induction of circulating interferon by tilorone hydrochloride were determined. Whereas protection was evident with doses of 0.15 and 1.5 mg/kg, interferon was not detected with doses lower than 150 mg/kg. Protection was apparently not dependent on interferon induction.

Interferon Levels and Resistance to Viral Infection Associated with Selected Interferon Inducers

Summary Comparative studies of protection of mice against infection with MM virus and levels of interferon induced by graded amounts of Escherichia coli endotoxin, statolon, maleic acid-divinyl ether copolymer, and polyinosinic-polycytidylic acid complex have been carried out. In every instance, both protection and interferon response were dose-dependent, but interferon titers did not correlate with protection. The degree of protection could not be correlated to any specified amount of interferon. Possible explanation of these results would include: (i) protective potency of interferon may differ with the type of inducer, (ii) different interferons are utilized for protection in different ways, or (iii) the protective effect of inducers used may be unrelated to interferon.

Role of Interferon in the Antiviral State Elicited by Selected Interferon Inducers

Summary Data are presented which show that protection of mice by endotoxin against viral infection is not mediated by interferon while that of poly(I:C) and pyran can be at least partially attributed to interferon induction. The results also suggest that circulating interferon does not protect against a virus administered intraperitoneally.

Myocardial lesions: spontaneous development in captive ground squirrels.

Summary Microscopic examination revealed that hearts of arctic ground squirrels killed in the field (noncaptive) were free of myocardial lesions but numerous areas of focal necrosis were found in the hearts of animals held captive for 2, 3, or 4 weeks. The etiology of these degenerative changes may be associated with the stress of captivity, but remains to be determined. The authors thank Robert E. Becker of the USAF Arctic Aeromedical Laboratory, Fort Wain-wright, Alaska, for supplying the ground squirrel hearts.

Induction of Viral Resistance by Poly I:C in Cells Which Apparently Produce No Interferon

Summary Data are presented which show that McCoy cells do not produce detectable levels of interferon but respond to the protective action of either interferon or poly I:C. Protection by poly I:C is blocked by actinomycin D treatment, suggesting that an active cellular process is required. It is concluded that, in McCoy cells, poly I:C acts through a mechanism other than interferon induction.