Host Cell-Specific Interactions

A complication to this perhaps simplistic reasoning arose with the observation that EMC infection of mouse L cells resulted in a rapid inhibition of host cell translation, prior to the utilization of viral mRNA to synthesize viral proteins (Jen and Thach, 1982). These kinetics differed from those observed in mouse plasmacytoma, Krebs, or Ehrlich ascites cells, and were not consistent with direct competition of viral with cellular mRNA to preferentially yield viral protein synthesis. Different responses in protein synthesis patterns by different cell types was also reported for mengovirus (Otto and Lucas-Lenard, 1980). 

Infected L cell extracts showed no reduction in initiation activity on cellular or globin mRNA in vitro. Fractionation of these extracts, however, revealed a marked increase in a component which stimulated translation of capped (but not uncapped EMC) mRNAs in the soluble (200,000 x g supernatant) cell fraction, compared with uninfected cells (Jen and Thach, 1982). This suggested that EMC infection of L cells resulted in a subcellular redistribution of at least 

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The surface of a virion contains many copies of one type of protein that binds specifically to multiple copies of a receptor protein on a host cell. This interaction determines the host range—the group of cell types that a virus can Infect—and begins the infection process. Most viruses have a rather limited host range. 

Among the known human retroviruses are human T-cell lymphotrophic virus (FITLY), which causes a form of leukemia, and human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS). Both of these viruses can infect only specific cell types, primarily certain cells of the immune system and, in the case of HIV, some central nervous system neurons and glial cells. Only these cells have cell-surface receptors that interact with viral envelope proteins, accounting for the host-cell specificity of these viruses. Unlike most other retroviruses, HIV eventually kills its host cells. The eventual death of large numbers of... 

The immobilisation of proteins into inorganic mesoporous host materials has attracted considerable attention due to the potential applications in biochemical, biomedical, industrial and bio-analytical fields [1] Biocompatible supports endowed with fluorescent tracers and adequately modified for specific interactions with cellular antigens are an amenable tool for image in living cells processes that are relevant to diseases. 

The endoparasite C. sonorensis has evolved with the ability to generate extrachromosomal genetic elements in the form of multiple double-stranded, superhelical DNA molecules. These DNA molecules are amplified in the calyx cell nucleus, packaged into viruses, and secreted in a complex process of viral maturation, which also provides a complex double viral envelope. One viral envelope is assembled in the cell nucleus, and the other is obtained during budding from the calyx cell surface into the oviduct lumen. Viral envelopes, which are derived from cellular membranes, may mediate species-specific virus host cell and tissue interactions. This could be one important aspect of the species-specific endoparasite-host relationship fundamental to parasite survival. 

Adsorption (Binding). The process of adsorption by a host cell depends first upon the operation of general intermolecular forces, then upon more specific interactions between the molecules of the nucleocapsid or the virus membrane and the molecules of the host cell membrane. In most cases there has... 

Host Cell Impurities Various organisms have been used to produce recombinant proteins yeast, bacteria (e.g., E. coli), insect cells, and mammalian cells such as Chinese hamster ovary (CHO) cells. During the purification process, some HCPs can copurify with the protein product. Because of the specificity of the antigen-antibody interaction, an ELISA can be used to detect and quantitate the contaminating HCPs. Detecting host impurities is important for quality process control as well as for product safety issues. The intent is to avoid unsafe levels of residual HCPs which might lead to adverse reactions.11... 

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