Enucleated cells

How does UV-induced free radical formation activate immune suppression Some have suggested that UV-induced cytokine production is involved. Because both DNA damage and oxidative stress can activate transcription of the cytokines that activate immune suppression,23>24one of the problems faced by investigators in the field was to divorce the effects of DNA damage from membrane oxidation. One approach was to look at the activation of transcription factors in UV-irradiated enucleated cells. Devary and colleagues25 observed that both NF-kB and AP-1 were activated in enucleated... 

You have extracted the nucleus from an oocyte. You have a nucleus and the rest of the cell. Neither of these two components is alive. Now you insert again the nucleus into the cell - or, in this respect - into a different enucleated cell (as in the cloning experiments). You get a living cell. Can this be taken as a demonstration for the emergence of life, to namely that hfe can be generated out of non-living components ... 

Studies of Con A induced agglutination of live cells are susceptible to complications such as irreversibility of the agglutinated cells upon aging (17), endocytosis of bound lectin (18) and effects of experimental conditions such as temperature, pH and ionic strength on membrane properties (J). Alternatively, the use of aldehyde-fixed cells (19), heatkilled cells (20), enucleated cells (21) and glycoprotein-incorporated liposomes (22) may lead to less problems being encountered. 

All functions of a cell need not remain intact to retain susceptibility to viral infections. However, loss of certain functions will predispose to resistance to certain viruses and not others. For example, cells enucleated by cytochalasin B will support the replication of vesicular stomatitis virus but not influenza virus, which also fails to inhibit protein synthesis in enucleated cells (Follett et al., 1974). 

Bossart and Bienz (1979) showed that poliovirus-infected enucleated HEp-2 cells exhibited the same cytopathic effect as poliovirus-infected nucleated cells. However, enucleated cells did not show the same redistribution of lysosomal enzymes (p-glucuronidase and p-glucosaminidase) into the cytoplasm as do infected nucleate cells however, it should be noted that enucleated cells do not support the replication of poliovirus as well as do nucleated cells. A temporal analysis of the events occuring in poliovirus-infected cells, as well as their cellular location, was made by Bienz et al. (1980). By kinetic analysis, viral protein synthesis was found to reach a maximum at 2.5 hr before cell alterations can even be detected. Poliovirus RNA synthesis reached a peak later (at 3.0-3.5 hr postinfection) when new vacuoles can be seen, although viral RNA synthesis continues as vacuoles coalesce to form the typical poliovirus cytopathic effect. Therefore, these authors consider that viral RNA synthesis and not protein synthesis is more closely related to structural changes possibly this could also include lysosomal structural changes. 

Follett, E. A. C., Pringle, C. R., Wunner, W. H. and Skehel, J. J., 1974, Virus replication in enucleate cells Vesicular stomatitis virus and influenza virus, J. Virol. 13 394. 

Fenwick, M. L., and Roizman, B., 1977, Regulation of herpesvirus macromolecular synthesis. VI. Synthesis and modification of viral polypeptides in enucleated cells, J. Virol. 22 720. 

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