An interference phenomenon in relation to yellow fever and other viruses

The infections produced in ferrets by human influenza virus and canine distemper virus were studied. Cross immunity and cross neutralization tests showed that these two viruses were not related antigenically. Ferrets infected with influenza virus alone rapidly produced considerable quantities of neutralizing antibodies, and after the 6th day virus was not demonstrable in their lungs. Ferrets infected with both influenza and distemper viruses simultaneously produced but small amounts of neutralizing antibody, and influenza virus persisted in undiminished concentration in their lungs throughout the course of the infection.

Section: Discussionsupporting

confidence: 63%

The Synergism of Human Influenza and Canine Distemper Viruses in Ferrets

Horsfall

Lennette

1940

“…This explanation might apply where the "interference" phenomenon has been observed in infections with animal viruses (10--19). In four instances ,involving different viruses (12,13,15,19), however, the manifestations of an otherwise serious virus disease were obscured after two apparently unrdated viruses had been inoculated within a few hours.…”

Section: Discussionmentioning

confidence: 99%

Multiple Virus Infection of Single Host Cells

Syverton

Berry

1947

In considering the intraceUular parasitism that characterizes the host-virus relationship, it has often been tacitly assumed that the parasitization of an individual host cell is limited to infection by a single virus. In contradiction to this belief, however, we have reported experiments (1) in which the cells of a Virus-induced tumor, Shope's rabbit papilloma (2), and of a carcinoma of the sort that frequently succeeds the benign growths (3, 4), were superinfected by other viruses--"superinfected" in the case of the papilloma because its cells contained the causative virus. These same studies, furthermore, included certain instances in which the simultaneous introduction of two viruses for the purpose of inducing superinfection was followed by evidence of the simultaneous activity of both of the viruses within individual cells. This evidence was the presence of two diagnostically significant inclusion bodies, the one cytoplasmic, the other intranuclear, within a single cell. In making our first report, we recognized that the histopathological examination of a stratified epithelial structure, such as the rabbit papilloma, involved the likelihood of error--of the mistaken interpretation that two overlying cells constituted a single cell. If such an error were made, the conclusion might be reached that the two inclusion bodies, cytoplasmic and intranuclear, were present in a single cell, when one of the inclusion bodies might actually be in one host cell and the other inclusion body in an overlying cell. It was for the purpose of eliminating, as far as possible, this opportunity for error that the present investigation was undertaken. The results of these experiments (5), which will now be described in detail, give evidence that an individual host cell can be simultaneously parasitized by more than one virus and amply confirm our earlier findings. Materials and MethodsThe five viruses employed in the present investigations were vaccinia, myxoma virus, B virus, herpes virus, and virus III. The strains of virus employed, and the method for the preparation of the virus suspensions have already been described in detail (1 ¢).Normal host cells for experimental infection were provided by using rabbit's cornea, akin, or testicle. Of the eleven rabbits employed, nine were domestic stock rabbits (Oryctolagus)

“…On the other hand, different conditions seem to obtain in those cases of viral interference in which the competing viruses represent pathogenic and non-pathogenic variants of the same strain, or are otherwise closely related. We are referring to such interference as occurs between the neurotropic and viscerotropic descendants of yellow fever virus or between the virus of yellow fever and the virus of Rift Valley fever; for even though the last two viruses and the diseases which they produce are seemingly unrelated, sufficient analogies exist to raise the question whether both viruses may not have originated from some common ancestral form (10). Obviously, the interference that is demonstrable between the pantropic murine strain of SK poliomyelitis virus and the neurotropic simian strains of poliomyelitis virus falls into the same category; and we probably do not go far astray by assuming that the basic mechanisms responsible for the several interference phenomena listed in this group are very similar.…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, Hoskins (9) found that intramuscular injection of a neurotropic strain of yellow fever virus, which is usually harmless for monkeys, protects these animals against simultaneous infection with a highly pathogenic viscerotropic strain of the same virus. Subsequently, Findlay and MacCallum (10) showed that the injection of a mixture of Rift Valley fever and yellow fever virus into rhesus monkeys served to save a majority of the animals from death by yellow fever infection; conversely, a single inoculation of mice with neurotropic yellow fever virus and pantropic Rift Valley fever virus definitely protected a few mice against the latter disease and delayed the death of others. A well marked sparing effect of the virus of lymphocytic choriomeningitis upon poliomyelitic infection in monkeys has also been described by Dalldorf and his associates (11).…”

mentioning

confidence: 99%

Studies in Rodent Poliomyelitis

Jungeblut

Sanders

1942

1. The murine strain of SK poliomyelitis virus interferes with the propagation in rhesus monkeys of SK, Aycock, and RMV poliomyelitis monkey virus. 2. This interference is demonstrable by intracerebral injection of mixtures of murine and monkey virus prepared in vitro as well as by separate injection of the two viruses by diverse routes. 3. Mixture tests carried out with graded doses of murine and monkey virus show that 0.5 cc. of a 10 per cent suspension prepared from the brains of paralyzed mice is capable of counteracting at least 100 minimal paralyzing doses of two strains of monkey virus. 4. No interference was demonstrable with suspensions of brains infected with murine virus which had been inactivated by heating for ½ hour at 75°C., or with suspensions prepared from normal mice, or with brain suspensions prepared from mice infected with herpes virus. 5. When murine virus is introduced into monkeys by the intravenous route, before or after intracerebral infection with monkey virus, distinct prophylactic or therapeutic results may be obtained. 6. Analysis of the figures shows that the success of interference depends upon (a) the size of the infecting dose of monkey virus, (b) the amount of murine virus injected, and (c) the choice of proper intervals between the injection of monkey and murine virus. 7. The mechanism of the interference phenomenon here described is discussed in the light of the available data.