Viruses interference between

However, in a systemic host of TMV (P. floridana) the infiltration of tannic acid (0.034%) 24 hours after virus inoculation reduced virus titer about 75% during the first week after infection. After two weeks there was no significant difference in total virus content between tannic acid-treated and water-treated samples. Thus tannic acid does interfere with virus synthesis at an early stage in a temporary way. 

In Moss (1992), the subject of interference between viruses is studied. He notes that a harmless virus can be used to negate the effects of a lethal virus. In experiments on mice infected with a rabies strain, the death rate could be reduced from 50% to 15% by injecting a harmless avian encephalitis virus (Moss, 1992, p. 441). 

Moss has another chapter about the use of MTH-68 vaccine, a unique form of immunotherapy developed by Laszlo K. Csatay, M.D., of Fort Lauderdale, Florida (Moss, 1992, pp. 437 44). It involves the interference between two viruses, which is a well-known phenomenon. One virus interferes with the activities of the other, in one way or another. The situation may also be looked upon as a case where one virus stimulates the immune system to destroy the other less desirable virus, the latter being the cause of the cancerous condition. 

Exposure of cells to HLA virus interfers with superinfection by intact virus (Borgert et al., 197I). Therefore, the low efficiency of HLA virus even at high concentrations could be due to interference between the physically intact but biologically inactivated RNA of HLA virus and the infectious RNA added later. 

Because of their interference with the interaction between the viral envelope gpl20 glycoprotein and the cellular CD4 receptor, poly anionic substances not only inhibit virus adsorption to the cells but also block syncytium (giant cell) formation between the HIV-infected (gpl20 + ) cells and uninfected (CD4 + ) cells. Since syncytium formation results in a selective destruction of the CD4+ cells, this syncytium formation may play an important role in the pathogenesis of AIDS (a hallmark of which is a progressive decline of the CD4+ cells). 

Alick Isaacs (1921-1967) and Jean Lindenmann (1924- ) publish their pioneering report on the drug interferon, a protein produced by interaction between a virus and an infected cell that can interfere with the multiplication of viruses. 

Caspase-8 is recruited to FADD via interaction between death effector domains. We found that ORF E8 of the equine herpes virus-2 encoded a protein with two predicted death effector domains. This protein, called v-FLIP, is also present in several other viruses including human herpes virus-8. It interferes with the apoptotic pathway of FasL by binding to FADD and potently inhibits TRAIL-mediated cell death (Thome et al., 1997). The sequence information from v-FLIP led to the discovery of a mammalian homo-logue, cellular FLIP (c-FLIP, also called CASPER/I-... 

Research work on the mode of action of these compounds furnished the theoretical basis for the chemical control of insects by means of chemosterilants, and most of the compounds showing such action were first described as antitumour agents. In no other field is the interaction between plant protection and human therapy so close as that between the chemotherapy of cancer and insect control by chemosterilants. The capacity of these substances to interfere with the biosynthesis of DNA served as the common theoretical basis. In addition to other effects such as antitumour and antimitotic effects, deactivation of viruses, etc., a characteristic outcome of this interference is the mutagenic effect and, closely related to this, inhibition of reproduction (Bofkovec, 1962). 

The mechanism of actions involves tubulin binding, reverse transcriptase inhibition, integrase inhibition and topoisomerase inhibition. Podophyllo-toxins bind to tubulin and are able to disrupt the cellular cytoskeleton and interfere with some vital virus processes. There is no relationship between the inhibition of reverse transcriptase (RT) and chemical structure in the case of lignans, because all the chemical antiviral structures are able to bind to the enzyme. As to the rest of the mechanism, there is not much information available. The effects of rabdosiin may be due to its topoisomerase inhibitory effects. Charlton concluded that the antiviral activity of lignans is not strong and that except for podophyllotoxin, which is used topically to treat various warts caused by HPV, none of them are of interest for commercial application. 

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