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Use of HeLa cells in Parvo Virus testing
Testing for how feline parvo virus and canine parvo virus infect cells and what pathways are taken; scientists used cat cells, mouse cells, cat and mouse hybrid cells, mink cells, dog cells, human cells, and HeLa cells. /> Both feline parvo virus and canine parvo virus enter their hosts, follow specific pathways, and infect at certain parts of cells before infecting major organs. Parvo viruses are specific viruses that are determined by what receptors they attack. /> Testing found that parvo virus infects carnivorous animals through the oropharyngeal pathway. Parvo virus infects the oropharyngeal cells that come in immediate contact with the virus. Parvo virus contains a plasmid that infects and binds to transferrin receptors, a glycoprotein, on the plasma membrane. /> />  The parvo virus plasmid is stored in a small non- enveloped capsid. />  Once oropharyngeal cells become infected the virus spreads to dividing lymph cells and continues to work to the bone marrow and spread to target organs through blood.

Testing of HeLa cells and human cells to exposure of both feline parvo virus and canine parvo virus resulted in infections of the cells at human transferrin receptors. When anti-bodies and parvo virus samples were added at the same time to human cells and HeLa cells it was found that no infection would take place; experiments showed that both human cells and HeLa cells have transferrin receptors but there is no evidence of humans contracting parvo virus.

Certain chromosomes in cells show more susceptibility to parvo virus than others. Testing of feline parvo virus on cat cells and cat mouse hybrid cells found cultures with cells having the highest concentrations of the C2 chromosome were the most highly infected cells. Slight mutations of binding sites were found to slow down or completely stop the infection of the given parvo virus; whereas cells that are naturally missing the receptors or are mutated to not have them cannot be mutated. Both feline parvo virus and canine parvo virus express plasticity during cellular infection. /> Although transferrin receptors may be limited on cell surfaces the parvo viruses will find available transferrin receptors and will use different pathways to gain entry to the cells plasma membrane. Unlike plasma membrane infection plasticity, all strains of parvo virus show related routes to the cell nucleus.

Canine parvo virus is a mutated strain of feline parvo virus. The conditions needed for the mutation had to be perfect for the virus to change species of infection. The mutation occurred in the capsid proteins of feline parvo virus that gave it the ability to infect dogs. Both viruses remain similar so once the mutation occurred strains of canine parvo virus had a tradeoff of becoming more receptive to canine cells and less receptive to feline cells; only mutated feline parvo virus, the canine parvo virus, can infect both species of cats and dogs cells but standard un- mutated feline parvo virus can only infect feline cells. Both feline parvo virus and canine parvo virus bind to and infect the transferrin receptors but both have different sequences in the cells and animals. Infection by both feline parvo virus and canine parvo virus are relatively quick; but because of constant mutation of canine parvo virus, canine parvo virus has a slower infection time than feline parvo virus. Studies of other strains of mutated canine parvo virus have revealed that changes in the viral capsid by just one protein can be fatal to the virus. Wrong mutations have been noted to lead to inability to bind to transferrin receptors, bind to non- receptive parts of the cell membrane, and identification of the virus by the host’s antibody cells.