The Defensive Role of the Interferon System

Abstract

The evidence relating the interferon system to the infectious process has been examined. The available evidence supports the view that the interferon system is an important component of the body's nonimmune defenses, which are probably the major causes of recovery from already established virus infections of body tissues. The interferon system can also serve to limit virus spread through the bloodstream. Factors which may influence the interferon system and thereby influence virus infection have been considered. Finally, evidence is presented which indicates that the interferon system is one of the determinants of virulence of certain viruses and is one of the determinants of some persistent virus infections.The discovery of interferons by Isaacs and Lindenmann (1) led, within a short time, to major revisions in concepts of cellular immunity and recovery of multicellular organisms from infection. The significance of the antiviral effect of the interferon system extends to virus infections of the acute, chronic, and oncogenic varieties. More recent evidence suggests that the interferon system may play a role during infection by Chlamydia and certain protozoal parasites. This section will consider the implications of the interferon system as a host defense during infection. Several reviews contain related information (2-9). A more detailed consideration of the various host defenses during viral infection will be published (10). COMPONENTS OF THE INTERFERON SYSTEMThe term "interferon system" is used because this anti-infectious mechanism is now thought to be divisible into several components. For the present purposes we will refer to interferon as a protein(s) which is produced or released by cells following viral infection and certain other stimuli. Available evidence suggests that interferon is not itself directly antiviral, but rather, it reacts with cells to induce the formation of a new intracellular substance which mediates the antiviral activity. This antiviral component of the interferon system may be a polypeptide or a protein.

Ganoderma Tsugae Mycelium Enhances Splenic Natural Killer Cell Activity and Serum Interferon Production in Mice

“…These observations lead us to think that the augmentation of the splenic NK activ ity in mice after administration of GTI may be due to the induced IFN elevation in the mice serum. Inter ferons have been categorized as IFN-a, IFN-/3, and IFN-y based on antigenic heterogeneity (15). In the present results, the serum IFN elevation induced by GTI was reduced by treatment of the serum with either anti- mouse IFN-(a + ,8) or IFN y .…”

Experimental encephalitis following peripheral inoculation of West Nile virus in mice of different ages

“…In our view, such findings fail to suggest a significant role for interferon in this experimental model. A more important role has been proposed for interferon in studies of genetically determined differences in the susceptibility of mice to West Nile virus (Baron, 1970;Hanson, Koprowski, Baron & Buckler, 1969).…”

Mechanism of Recovery From Systemic Vaccinia Virus Infection

“…In general, passive transfer of even large amounts of antibody has not exerted a protective effect when the virus has been introduced directly into an organ such as the brain (24). There are, however, at least two reports of instances in which transfer of antibody may have enhanced the recovery process (25,26).…”